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This application is a continuation of application Ser. No. 08/720,671, filed Oct. 2, 1996, now abandoned, which in turn is a continuation of application Ser. No. 08/467,189, filed Jun. 6, 1995, now abandoned, which in turn is a divisional application of application Ser. No. 08/360,944, filed Dec. 21, 1994, now U.S. Pat. No. 5,616,512. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for manufacturing integrated circuits, particularly of intelligent power semiconductor devices. 2. Discussion of the Related Art In manufacturing integrated circuits, the problem of obtaining chip regions which are electrically insulated from one another exists. For example, in power semiconductor devices provided with on-chip driving circuitry (also called intelligent power semiconductor devices), the power device must be electrically insulated from the driving circuitry. The most common technique to achieve this electrical insulation is PN junction isolation. However, this technique gives rise to some problems, especially related to the introduction of parasitic components. Considering for example a Vertical Intelligent Power semiconductor device (VIP), such as an NPN power bipolar transistor constituted by an N++ emitter region diffused into a P-type base region which is in turn diffused into an N-type epitaxial layer representing the collector of the transistor. The driving circuitry is obtained inside a P-type well which is diffused into the N-type epitaxial layer and connected to the lowest voltage among those utilized in the chip to keep the P-type well/N-type epitaxial layer junction reverse biased. Inside the P-type well, vertical NPN transistors and lateral PNP transistors are generally obtained. In this structure, a number of parasitic bipolar transistors are present, both NPN and PNP, having base, emitter and collector represented by the various P-type or N-type regions inside the P-type well, the P-type well itself and the N-type epitaxial layer. Another PNP parasitic transistor has emitter, base and collector respectively represented by the P-type base region of the power transistor, the N-type epitaxial layer and the P-type well. All such parasitic components limit VIP performances. SUMMARY OF THE INVENTION In view of the state of art described, the object of the present invention is to develop a process for manufacturing integrated circuits, particularly for intelligent power semiconductor devices which creates devices wherein the electrical insulation between various semiconductor regions does not give rise to parasitic components. According to the present invention, this object is attained by means of a process for manufacturing integrated circuits which includes the following steps. An oxide layer is formed on at least one surface of two respective semiconductor material wafers to obtain a single semiconductor material wafer with a first layer and a second layer of semiconductor material and a buried oxide layer interposed therebetween starting from said two semiconductor material wafers by direct bonding of the oxide layers previously grown. The single wafer is exposed to a controlled reduction of the thickness of the first layer of semiconductor material, and then the top surface of the first layer of semiconductor material is lapped. Next dopant impurities are selectively introduced into selected regions of the first layer of semiconductor material to form the desired integrated components. An insulating material layer is then formed over the top surface of the first layer of semiconductor material. The insulating material layer, and the first layer of semiconductor material are selectively etched down to the buried oxide layer to form trenches laterally delimiting respective portions of the first layer of semiconductor material wherein integrated components are present which are to be electrically isolated from other integrated components. Finally, the walls of the trenches are coated with an insulating material and the trenches are filled with amorphous silicon According to the present invention, it is possible to fabricate integrated circuits, particularly intelligent power semiconductor devices with an integrated driving circuitry, which are not affected by the presence of parasitic devices since the electrical isolation between the various devices is not accomplished by means of junction isolation, but by means of dielectric isolation. If the integrated circuit to be fabricated is an intelligent power semiconductor device with an integrated driving circuitry, the process according to the invention comprises two additional steps. The first semiconductor material layer is selectively etched down to the buried oxide layer to obtain selected portions of the single wafer wherein the buried oxide layer is uncovered, and dopant impurities are selectively introduced into selected regions of the second layer of semiconductor material to form the desired power device. It is thus possible to fabricate intelligent power semiconductor devices with an integrated driving circuitry which are not affected by the presence of parasitic devices since the electrical isolation between the power devices and the driving circuitry and between the various components of the driving circuitry is not accomplished by means of junction isolation, but by means of dielectric isolation. The features of the present invention will be made more evident by the following detailed description of its preferred embodiment, illustrated as a non-limiting example in the annexed drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 7 are cross-sectional views of a part of an integrated circuit taken at intermediate steps of a manufacturing process according to the preferred embodiment of the invention. DETAILED DESCRIPTION As shown in FIG. 1, a manufacturing process according to the invention starts from two distinct silicon wafers 1 and 2, generally doped with donor impurities. A first wafer 1 comprises an N-type semiconductor bulk 9 and an N+ heavily doped silicon layer 3 at its bottom surface The second wafer 2 has resistivity and thickness values depending on the particular power device that is to be obtained. The two silicon wafers 1 and 2 are then submitted to a thermal oxidation process to grow on the bottom surface of the first wafer 1 and on the top surface of the second wafer 2 respective thermal oxide layers 5 and 6. During this step, thermal oxide layers 4 and 7 are also grown on the top surface of the first wafer 1 and the bottom surface of the second wafer 2, respectively. The two wafers 1 and 2 are then bonded together by means of the so-called "Silicon Direct Bonding" (SDB) technique, known per se and described for example in the European Patent Application No. 89202692.3. After this step, a single silicon wafer is obtained from the two silicon wafers 1 and 2. The bottom oxide layer 5 of the first wafer 1 and the top oxide layer 6 of the second wafer 2 constitute a single oxide layer 8 sandwiched between the second wafer 2 and the N+ layer 3 of the first wafer 1, and thus, this oxide layer is buried under the first wafer 1 (FIG. 2). Among the various Silicon On Insulator (SOI) techniques, the SDB technique produces buried oxide layers of better quality. The top oxide layer 4 of the first wafer 1 and the bottom oxide layer 7 of the second wafer 2 are then removed, and the N-type semiconductor bulk 9 of the first wafer 1 is submitted to a controlled reduction of its thickness. The top surface of the N-type semiconductor bulk 9 of the first wafer 1 is then polished by means of a precision lapping and polishing machine (with a thickness tolerance of about 0.1 mm). The top surface of N-type semiconductor bulk 9 of the first wafer 1, at the end of these steps, represents the top side of the single silicon wafer composed by the two bonded silicon wafers 1 and 2 (FIG. 3). If the integrated device to be fabricated is a Vertical Intelligent Power (VIP) device, such as a bipolar power transistor, the N-type semiconductor bulk 9 and the N+ layer 3 of the first wafer 1 are selectively etched and removed down to the single oxide layer 8. At the end of this step, within all the regions 10 of the single silicon wafer wherein power devices are to be fabricated, the buried oxide layer 8 is uncovered. However, within all the regions 11 reserved to the driving circuitries for the power devices, the oxide layer 8 is still buried under the N-type semiconductor bulk 9 and the N+ layer 3 (FIG. 4). It is important to note that the etching angle a should be as small as possible, to avoid the creation of high steps so that the following depositions of the various layers (such as vapox, aluminum, nitride, etc.) is readily facilitated. After this step, a thermal oxide layer is grown over the entire top surface of the wafer, i.e. over the top surface of the N-type silicon bulk 9 (in the wafer regions 11) and over the uncovered oxide layer 8 (in the wafer regions 10). The power devices and their driving circuitries are fabricated in their respective wafer regions 10 and 11 according to a standard and per se known manufacturing process. It is to be noted that if the depth of field of the photolitographic apparatus employed in the manufacturing process is lower than the difference in height between the wafer regions 11 and 10, all the photolitographic steps in the wafer regions 10 reserved to the power devices are to be performed separately from those in the wafer regions 11 reserved to the driving circuitries. FIG. 5 shows on an enlarged scale a part of a wafer region 11 wherein a vertical NPN transistor is present. As known to anyone skilled in the art, the transistor comprises a P-type base region 12 diffused into the N-type semiconductor bulk 9, and an N+ emitter region 13 diffused into said base region 12. The collector region is represented by a portion of the N-type semiconductor bulk 9 which is located under the emitter region 13. When the transistor is biased in the forward active region, electrons are injected from the emitter region 13 into the base region 12 wherefrom they diffuse into the collector region. The N+ layer 3 represents a buried layer offering a low resistive path for the electrons to an N+ collector contact region 14. To electrically insulate the transistor shown in FIG. 5 from other integrated components defined in the same wafer region 11, the process according to the present invention provides for the realization of vertical trenches. To obtain said trenches, a per se known technique is used providing for the deposition over the top surface of the N-type silicon bulk 9 of an insulating material layer generally composed by three layers: a thin thermal oxide layer 15; a nitride layer 16 and a vapour-deposited oxide layer ("vapox") 17 (FIG. 5). Successively, the three layers 15, 16 and 17, together with the N-type semiconductor bulk 9 and the N+ layer 3, are selectively etched down to the buried oxide layer 8, to form a trench 18 around the lateral transistor shown as well as around all the other elements of the driving circuitry in the wafer region 11 which are to be electrically isolated from one another (FIG. 6). The trench 18 must then be filled with an insulation material. According to the known technique, the walls of the trench 18 are first covered by an oxide layer 19, and the trench 18 is filled with amorphous silicon 20. In this way the wafer region 11 is divided into portions which are electrically insulated from one another laterally by means of the trench 18 and at the bottom by means of the buried oxide layer 8. The top surface of the N-type silicon bulk 9 is then planarized, the three layers 15, 16 and 17 are removed from the surface of the N-type bulk 9, and a thermal oxide layer 21 is grown over the entire surface. Said oxide layer 21 is then selectively etched to form contact areas 22 (FIG. 7), and an aluminum layer (not shown) is deposited over the thermal oxide layer 21 and selectively etched to form the desired pattern of interconnection lines between the various components. The process according to the present invention is suitable for the manufacturing of integrated circuits in general and not only of VIP devices. If no power devices are to be fabricated, neither the step of selective removal of the N-type semiconductor bulk 9 and of the N+ layer 3, nor the subsequent thermal oxidation of the entire wafer surface, are performed. Apart from these differences, the process is totally similar to that already described. Having thus described one particular embodiment of the invention, various alterations, modifications and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements are intended to be part of this disclosure and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only, and not intended as limiting the invention is limited only as defined in the following claims and equivalents thereto.

Semiconductor device chips having a first layer of semiconductor material, a second layer of a semiconductor material and an insulating layer disposed therebetween. The first layer of semiconductor material has doped semiconductor regions disposed therein, and the second layer of semiconductor material has a power device disposed therein. The power device is disposed beneath the doped semiconductor region of the first layer. Trenches may be located within the first layer of semiconductor material to electrically isolate different areas having doped semiconductor regions. The insulating layer is typically formed from an oxide.

CROSS-REFERENCE [0001] This application claims the benefit of U.S. Provisional Application No. 61/175,397, filed May 4, 2009, which application is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] Diabetes mellitus is a disease characterized by elevated levels of plasma glucose. Uncontrolled hyperglycemia is associated with increased risk of vascular disease including, nephropathy, neuropathy, retinopathy, hypertension, and death. There are two major forms of diabetes. Type 1 diabetes (or insulin-dependent diabetes) and Type 2 diabetes (or noninsulin-dependent diabetes). The American Diabetes Association has estimated that approximately 6% of the world population has diabetes. The goal of diabetic therapy is to maintain a normal level of glucose in the blood. The American Diabetic Association has recommended that diabetics monitor their blood glucose level at least three times a day in order to adjust their insulin dosages and/or their eating habits and exercise regimen. While, glucose tests can only measure a point in time result and do not provide an overall assessment of glycemic control over a period of time, it is an important tool in diabetes care management. [0003] Integrated cell phones with glucose testing capabilities have been developed. However, a significant drawback to these integrated devices is that they do not provide the opportunity to upgrade glucose hardware or meter functionality without replacing the entire phone. Moreover, if either the phone or glucose testing functionality is damaged, the entire device must be replaced to regain full functionality. In addition, for example, the iPhone® and iPod® Touch offer superior graphics and data display capability potential, along with the flexibility of unlimited applications to manage data and communications. [0004] Other efforts to develop integrated treatment system with a glucose meter include, for example, insulin pump and wrist strap controller, as well as an effort to integrate the glucose meter and a cell phone. These integrated glucose meter/cellular phone combinations are under testing and currently cost $149.00 USD retail. Testing strips are proprietary and available only through the manufacturer without reimbursement by an insurance company. These “Glugophones” are currently offered in at least three forms: as a dongle for the iPhone, an add-on pack for LG model UX5000, VX5200, and LX350 cell phones, as well as an add-on pack for the Motorola Razr® cell phone. This further limits providers to AT&T for the iPhone and Verizon for the others. Similar systems have been tested for a longer time in Finland. SUMMARY OF THE INVENTION [0005] Module adaptable to communicate with a suitable handheld devices or PDAs. Suitable devices include, but are not limited to, the Apple iPhone® or iPod®, Research in Motion Blackberry® smart phones, Motorola Droid smart phones, and Palm Pre smart phones. The module can be used without adding to the cost of the handheld device. This allows direct reimbursement for the replaceable meter module portion if payers choose to limit coverage for the full system, as well as the possibility of reimbursement for the entire system including the handheld device. Other solutions build the cost into the phone, which must be replaced to upgrade or replace the glucose function. Moreover, information from the glucose meter reading can be communicated from the PDA to a remote station for reporting the results. With an iPod-like approach, this could be accomplished without the need for a cellular signal or carrier, as long as a WiFi internet connection is available anywhere in the world. [0006] The glucose device described here is an attachment module using the standard connector interface of the handheld device. A single module could be used on multiple handheld devices, saving cost. This flexibility also means that the module could be used with a handheld device, such as an iPod, in the gym, or with a handheld device, such as an iPhone, in the office, etc. Since it is detachable, it does not require extra space or size in the handheld devices itself—it is only attached when a reading is required. It also does not add cost to the handheld device hardware, unlike the integrated units. The functionality of the module could range from a simple electronic interface to the strip (using the handheld device to do all calculations, data processing, display, and communications with health care providers or data services) to an interface plus glucose calculation engine (where the module delivers an answer, and the handheld device provides further data processing, display, and communications with health care providers or data services) to a fully contained meter with a small display, using the handheld device for much richer data processing, display, and communications. [0007] An aspect of the disclosure is directed to an apparatus for use to determine blood glucose levels. The apparatus comprises: an aperture adapted and configured to receive a glucose test strip; a detector adapted and configured to detect at least one of a presence or amount of a substance indicative of glucose level; a connector adapted and configured to engage the first device; a power source; and one or more input buttons or touch screen controls wherein the apparatus further comprises a logic apparatus adapted and configured to read instructions from a computer readable storage media associated with at least one of a first device having connectable to the Internet and the apparatus, wherein the computer readable storage media is configured to tangibly store thereon computer readable instructions. Components, such as the logic apparatus and detector can be positioned within a suitable housing or can be configured to be engaged to functionally form a housing. The apparatus is typically handheld. A display screen adapted and configured to display at least one of instructions or measurement results can also be provided. A data processor can be adapted to determine a blood glucose value from a measurement. [0008] Another aspect of the disclosure is directed to a method for detecting the blood glucose levels. The method comprises: obtaining a sample from a mammal; applying the sample to a test strip wherein the test strip is inserted into an aperture adapted and configured to receive the strip in an apparatus further comprising a detector adapted and configured to detect at least one of a presence or amount of a substance indicative of glucose level; a connector adapted and configured to engage the first device; a power source; and one or more input buttons or touch screen controls, wherein the apparatus further comprises a logic apparatus adapted and configured to read instructions from a computer readable storage media associated with at least one of a first device having connectable to the Internet and the apparatus, wherein the computer readable storage media is configured to tangibly store thereon computer readable instructions; and determining a glucose level from the sample; communicating the glucose level to a handheld apparatus in communication with the blood glucose apparatus. Additional method steps can include, for example, one or more of, instructing a device with mobile communication functionality to contact one or more of an emergency service agency, doctor, and caregiver; displaying results of a the blood glucose measurement; and storing the measurement results on a memory device. [0009] Still another aspect of the disclosure is directed to a networked apparatus for determining blood glucose. The networked apparatus comprises: a memory; a processor; a communicator; a display; and an apparatus for detecting a blood glucose level comprising an aperture adapted and configured to receive a glucose test strip; a detector adapted and configured to detect at least one of a presence or amount of a substance indicative of glucose level; a connector adapted and configured to engage the first device; a power source; and one or more input buttons or touch screen controls, wherein the apparatus further comprises a logic apparatus adapted and configured to read instructions from a computer readable storage media associated with at least one of a first device having connectable to the Internet and the apparatus, wherein the computer readable storage media is configured to tangibly store thereon computer readable instructions. [0010] Still another aspect is directed to communication system. The communication system comprises: an apparatus for detecting blood glucose level comprising an aperture adapted and configured to receive a glucose test strip; a detector adapted and configured to detect at least one of a presence or amount of a substance indicative of glucose level; a connector adapted and configured to engage the first device; a power source; and one or more input buttons or touch screen controls, wherein the apparatus further comprises a logic apparatus adapted and configured to read instructions from a computer readable storage media associated with at least one of a first device having connectable to the Internet and the apparatus, wherein the computer readable storage media is configured to tangibly store thereon computer readable instructions; a server computer system; a measurement module on the server computer system for permitting the transmission of a measurement from a system for detecting blood glucose levels over a network; at least one of an API engine connected to at least one of the system for detecting blood glucose levels and the device for detecting blood glucose levels to create an message about the measurement and transmit the message over an API integrated network to a recipient having a predetermined recipient user name, an SMS engine connected to at least one of the system for detecting blood glucose levels and the device for detecting blood glucose levels to create an SMS message about the measurement and transmit the SMS message over a network to a recipient device having a predetermined measurement recipient telephone number, and an email engine connected to at least one of the system for detecting blood glucose levels and the device for detecting blood glucose levels to create an email message about the measurement and transmit the email message over the network to a recipient email having a predetermined recipient email address. Additionally, the system can further comprise a storing module on the server computer system for storing the measurement on the system for detecting blood glucose levels server database. In some configurations at least one of the system for detecting blood glucose levels and the device for detecting blood glucose levels is connectable to the server computer system over at least one of a mobile phone network and an Internet network, and a browser on the measurement recipient electronic device is used to retrieve an interface on the server computer system. Additionally, a plurality of email addresses can be held in a system for detecting blood glucose levels database and fewer than all the email addresses are individually selectable from the diagnostic host computer system, the email message being transmitted to at least one recipient email having at least one selected email address. wherein at least one of the system for detecting blood glucose levels and the device for detecting blood glucose levels is connectable to the server computer system over the Internet, and a browser on the measurement recipient electronic device is used to retrieve an interface on the server computer system. A plurality of user names can be held in the system for detecting blood glucose levels database and fewer than all the user names are individually selectable from the diagnostic host computer system, the message being transmitted to at least one measurement recipient user name via an API. Additionally, measurement recipient electronic device (e.g., smart phone, computer or glucose measurement device) is connectable directly or indirectly to the server computer system over the Internet, and a browser on the measurement recipient electronic device is used to retrieve an interface on the server computer system. Typically, the measurement recipient electronic device is connected to the server computer system over a cellular phone network. In many cases, the measurement recipient electronic device is a mobile device. An interface can also be provided on the server computer system, the interface being retrievable by an application on the mobile device. An SMS message is received by a message application on the mobile device. In some instances, a plurality of SMS messages are received for the measurement, each by a respective message application on a respective recipient mobile device. Typically, at least one SMS engine receives an SMS response over the cellular phone SMS network from the mobile device and stores an SMS response on the server computer system. Additionally, the measurement recipient phone number ID is transmitted with the SMS message to the SMS engine and is used by the server computer system to associate the SMS message with the SMS response. The server computer system can be configured to be connectable over a cellular phone network to receive a response from the measurement recipient mobile device. Additionally, the SMS message can include a URL that is selectable at the measurement recipient mobile device to respond from the measurement recipient mobile device to the server computer system, the server computer system utilizing the URL to associate the response with the SMS message. In some configurations, the system can further comprise, a downloadable application residing on the measurement recipient mobile device, the downloadable application transmitting the response and a measurement recipient phone number ID over the cellular phone network to the server computer system, the server computer system utilizing the measurement recipient phone number ID to associate the response with the SMS message; a transmissions module that transmits the measurement over a network other than the cellular phone SMS network to a measurement recipient user computer system, in parallel with the measurement that is sent over the cellular phone SMS network; and/or a downloadable application residing on the measurement recipient host computer, the downloadable application transmitting a response and a measurement recipient phone number ID over the cellular phone network to the server computer system, the server computer system utilizing the measurement recipient phone number ID to associate the response with the SMS message. [0011] Another aspect of the disclosure is directed to a networked apparatus. The networked apparatus comprises: a memory; a processor; a communicator; a display; and an aperture adapted and configured to receive a glucose test strip; a detector adapted and configured to detect at least one of a presence or amount of a substance indicative of glucose level; a connector adapted and configured to engage the first device; a power source; and one or more input buttons or touch screen controls, wherein the apparatus further comprises a logic apparatus adapted and configured to read instructions from a computer readable storage media associated with at least one of a first device having connectable to the Internet and the apparatus, wherein the computer readable storage media is configured to tangibly store thereon computer readable instructions. [0012] Still another aspect of the disclosure is directed to a communication system. The communication system comprises: an apparatus for detecting blood glucose level comprising an aperture adapted and configured to receive a glucose test strip; a detector adapted and configured to detect at least one of a presence or amount of a substance indicative of glucose level; a connector adapted and configured to engage the first device; a power source; and one or more input buttons or touch screen controls, wherein the apparatus further comprises a logic apparatus adapted and configured to read instructions from a computer readable storage media associated with at least one of a first device having connectable to the Internet and the apparatus, wherein the computer readable storage media is configured to tangibly store thereon computer readable instructions; a server computer system; a measurement module on the server computer system for permitting the transmission of a measurement from a system for detecting blood glucose levels over a network; at least one of an API engine connected to at least one of the system for detecting blood glucose levels and the device for detecting blood glucose levels to create an message about the measurement and transmit the message over an API integrated network to a recipient having a predetermined recipient user name, an SMS engine connected to at least one of the system for detecting blood glucose levels and the device for detecting blood glucose levels to create an SMS message about the measurement and transmit the SMS message over a network to a recipient device having a predetermined measurement recipient telephone number, and an email engine connected to at least one of the system for detecting blood glucose levels and the device for detecting blood glucose levels to create an email message about the measurement and transmit the email message over the network to a recipient email having a predetermined recipient email address. A storing module can also be provided on the server computer system for storing the measurement on the system for detecting blood glucose levels server database. In some configurations at least one of the system for detecting blood glucose levels and the device for detecting blood glucose levels is connectable to the server computer system over at least one of a mobile phone network and an Internet network, and a browser on the measurement recipient electronic device is used to retrieve an interface on the server computer system. Additionally, a plurality of email addresses are held in a system for detecting blood glucose levels database and fewer than all the email addresses are individually selectable from the diagnostic host computer system, the email message being transmitted to at least one recipient email having at least one selected email address. In some configurations, at least one of the system for detecting blood glucose levels and the device for detecting blood glucose levels is connectable to the server computer system over the Internet, and a browser on the measurement recipient electronic device is used to retrieve an interface on the server computer system. A plurality of user names can be held in the system for detecting blood glucose levels database and fewer than all the user names are individually selectable from the diagnostic host computer system, the message being transmitted to at least one measurement recipient user name via an API. Moreover, the measurement recipient electronic device is connectable to the server computer system over the Internet, and a browser on the measurement recipient electronic device is used to retrieve an interface on the server computer system. The measurement recipient electronic device can be connected to the server computer system over a cellular phone network, such as where the measurement recipient electronic device is a mobile device. Additionally, an interface on the server computer system, the interface being retrievable by an application on the mobile device. The SMS message can be received by a message application on the mobile device and, in at least some instances, a plurality of SMS messages are received for the measurement, each by a respective message application on a respective recipient mobile device. At least one SMS engine can be configured to receive an SMS response over the cellular phone SMS network from the mobile device and stores an SMS response on the server computer system. A measurement recipient phone number ID is transmitted with the SMS message to the SMS engine and is used by the server computer system to associate the SMS message with the SMS response. A server computer system is connectable over a cellular phone network to receive a response from the measurement recipient mobile device. The SMS message can includes, for example, a URL that is selectable at the measurement recipient mobile device to respond from the measurement recipient mobile device to the server computer system, the server computer system utilizing the URL to associate the response with the SMS message. The system can further include a downloadable application residing on the measurement recipient mobile device, the downloadable application transmitting the response and a measurement recipient phone number ID over the cellular phone network to the server computer system, the server computer system utilizing the measurement recipient phone number ID to associate the response with the SMS message; a transmissions module that transmits the measurement over a network other than the cellular phone SMS network to a measurement recipient user computer system, in parallel with the measurement that is sent over the cellular phone SMS network; a downloadable application residing on the measurement recipient host computer, the downloadable application transmitting a response and a measurement recipient phone number ID over the cellular phone network to the server computer system, the server computer system utilizing the measurement recipient phone number ID to associate the response with the SMS message. INCORPORATION BY REFERENCE [0013] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. BRIEF DESCRIPTION OF THE DRAWINGS [0014] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which: [0015] FIG. 1A is a perspective view of a handheld device suitable for use with the invention; [0016] FIG. 1B is a depiction of a testing strip suitable for glucose testing; [0017] FIG. 2A is a depiction of a handheld device in communication with an attachable glucose monitor; [0018] FIG. 2B is a depiction of a handheld device in communication with an attachable glucose monitor wherein the monitor has a read-out screen; [0019] FIGS. 3A-B are schematic block diagrams of devices for diabetes monitoring; [0020] FIG. 4 is a flow chart illustrating method steps; and [0021] FIG. 5A is a block diagram showing a representative example of a logic device through which a dynamic modular and scalable system can be achieved; and [0022] FIG. 5B is a block diagram showing the cooperation of exemplary components of a system suitable for use in a system where dynamic data analysis and modeling is achieved. DETAILED DESCRIPTION OF THE INVENTION [0023] Currently there is no way for a handheld device to directly interface with a blood glucose meter thereby providing the potential for a rich data processing, display, and communications capabilities of the handheld device (e.g., iPhone and iPod Touch). These configurations provide the advantage of: flexibility of functionality and reimbursement coverage; ability for module provider to upgrade module over time without user having to upgrade phone; ability for any diabetes company to develop a module to work with the handheld device. These benefits also limit the cost of phone hardware and provide limited capability to develop and use future applications. [0024] The present invention relates to glucose monitoring systems and methods, and more particularly to a system that adapts to engage a handheld device and which is configured to monitor the amount and rate of change of glucose in a patient, communicating the results to an easy-to-read display of such monitored information. I. DEVICE PLATFORM/INTERFACE [0025] FIG. 1 a illustrates a suitable smart phone device or handheld device 100 suitable for use in the system described. The handheld device 100 has a touch screen 102 and ports 104 suitable for use as, for example, data import and export, and buttons 106 . However, as will be appreciated by those in skill in the art, a device which provides a keyboard could also be used without departing from the scope of the invention. FIG. 1 b illustrates a standard glucose test strip 110 , such as those currently available from J&J and Abbot Diabetes Care. [0026] A standard connector interface adapted to communicate with the handheld device 100 , such as a iPhone/iPod dock connector can be used to achieve communication of information between the handheld device and, for example, a measurement device or other peripheral device. [0027] As illustrated in FIGS. 2 a and 2 b, the handheld device 200 is adapted and configured to engage the glucose measurement device 220 . The handheld device and glucose measurement device connection can be wireless (e.g., Blue Tooth), or wired. The device 200 is illustrated to include a touch screen 202 , ports, 204 , and buttons 206 . A test strip 210 is inserted into an aperture or channel configured to receive the strip. An aperture for receiving the test strip could, for example, be positioned on the glucose meter from a side of the measurement device that does not engage the handheld device, as illustrated in FIGS. 2 . In the configuration shown in FIG. 2 b, a display 222 is also provided. The test strip 210 typically contains a chemical for detecting glucose, such as glucose oxidase. This chemical reacts with the glucose in the blood sample provided by the user to create gluconic acid. Gluconic acid then reacts with, for example, ferricyanide, to create ferrocyanide. Once the ferrocyanide is created, the measurement device 220 runs an electronic current through the blood sample on the strip 210 . This current is then able to detect the ferrocyanide and determine how much glucose is in the sample of blood on the test strip 210 . That number is then relayed on the screen of the measurement device or on the handheld device connected to the measurement device. [0028] FIG. 3A-B is an illustration of a measurement device 320 . A power source 330 , which may be removable, adapted and configured to provide power to the system, is shown. The power source 330 can be removable, rechargeable, or fixed (as in the case of a power cord). Suitable power sources include, but are not limited to, batteries. The power source 330 may be activated by a control button 334 . Moreover, power can come from an auxiliary device that the measurement device is connected to such as a computer or mobile phone. Additionally, a microcontroller can be provided on the device in order to facilitated manipulation and analysis of the information obtained from the sample. Alternatively, the information can be transmitted to a secondary device for manipulation. [0029] An electromagnetic data storage device 336 (such as ROM, RAM, digital data storage, etc., such as in devices where data processing is provided) can be provided which stores instructions for operation of the measurement device. A memory, flash memory, and/or a full chip set or integrated circuit can be provided that interfaces (such as universal serial bus (USB) with the device. For the purposes of this disclosure a computer readable medium stores computer data, which data can include computer program code that is executable by a computer, in machine readable form. Computer readable medium may comprise computer readable storage media, for tangible or fixed storage of data, or communication media for transient interpretation of code-containing signals. Computer readable storage media includes physical or tangible storage (as opposed to signals) and includes without limitation volatile and non-volatile, removable and non-removable storage media implemented in any method or technology for the tangible storage of information such as computer-readable instructions, data structures, program modules or other data. Computer readable storage media includes, but is not limited to, RAM, ROM, EPROM, EEPROM, flash memory or other solid state memory technology, CD-ROM, DVD, or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other physical or material medium which can be used to tangibly store the desired information or data or instructions and which can be accessed by a computer or processor. [0030] A port or channel 340 is provided for interfacing with the test strip (shown above). Additionally, input buttons 338 can be provided that enable a user to input information into the device itself. In some configurations a display 350 is provided. Suitable displays include, for example, liquid crystal displays (LCD). [0031] As will be appreciated by those skilled in the art, the system can be contained within a suitably designed housing 332 or the components can be configured such that the components are interconnected in such a way as to function as a housing. A channel or port 340 is provided which is adaptable and configurable to receive a commercially available glucose test strip (shown in FIG. 2 ). A blood sample placed in fluid communication with the test strip which then determines the amount of ferrocyanide by measuring an electrical current. [0032] As will be appreciated by those skilled in the art, connectivity can also be provided which enables the system to send the information to a printer, or a network. Connectivity can be, for example, wirelessly via the internet as well as via suitable connection ports. II. GLUCOSE MEASUREMENTS [0033] Electrochemical glucose monitors consist of a disposable sensor strip ( 110 , in FIG. 1 ) that is made with multiple layers of conductive and reactive components, including enzymes to catalyze the reaction of the blood glucose in proximity to electrodes which capture and carry the generated current through conductors to the measurement electronics. Examples include, but are not limited to LifeScan's OneTouch Ultra® series, or Abbott's Therasense FreeStyle® series, or Roche's Accu-Chek®. FIG. 2 illustrates the OneTouch Ultra ® sensor strip, with 3 electrical contact connections on the left and blood application capillary on the right. [0034] The module adaptor is adapted for measuring blood glucose values and for generating blood glucose data in response to measuring said blood glucose values. As discussed more fully below, the module adaptor can be configured such that it is connected to a glucose measuring apparatus. Moreover, the monitor can be adapted and configured such that it is capable of receiving, storing and evaluating data. Examples include: (a) receiving and storing blood glucose data, (b) receiving and storing physician-supplied data, (c) prompting and receiving patient input into the monitor means at periodic times of patient data relating to diet, exercise, emotional stress and symptoms of hypoglycemia and other illness experienced by the patient during a preceding time period, (d) receiving and storing the patient data supplied by the patient, and (e) generating recommendations relative to patient insulin dosage based at least in part upon the received blood glucose data, physician data and patient data. III. METHODS [0035] Typical Use Steps are illustrated in FIG. 4 : Typical use steps include connecting a glucose measurement device to handheld device 410 , e.g., through standard dock interface, a cable, or Blue Tooth connection; once the two devices are in communication, the adaptor of the invention powers-up 420 , confirms ready to insert strip; instructions may then be provided to apply blood to the test strip; thereafter the device measures glucose from the sample 430 by automatically starting, and counts down to result; reports result 440 , either on handheld device 450 or the measurement device, and/or instructing the device to call emergency services 460 (e.g., 911) where the sugar level is below a pre-set or patient-specific pre-determined threshold, and/or storing the data 470 on either the measurement device or the handheld device to which the measurement device is attached. [0036] The handheld device can then be used to chart data, graph data, sort and trend data for specifics like “pre-breakfast” etc. (standard and new custom applications are possible); handheld device can transmit sets of data to diabetes professionals for further analysis or advice. Moreover, parameters can be set for the device where transmission of data occurs when, for example, a reading exceeds a certain blood glucose threshold; a series of readings exceeds an blood glucose trend, etc. Where a patient takes a blood reading and the blood glucose level is dangerously low —thus resulting in the patient being confused and unable to make a call for emergency assistance—the device could call 911 and provide a message that the patient has a dangerously low blood glucose level and may not be able to stabilize without professional intervention. IV. GLUCOSE MOBILE ADAPTOR DEVICES AND COMMUNICATION NETWORKS [0037] As will be appreciated by those skilled in the art, modular and scalable system employing one or more of the glucose measurement devices discussed above can be provided which comprises a controller and more than one glucose measurement devices. Controller communicates with each glucose measurement device over a communication media. Communication media may be a wired point-to-point or multi-drop configuration. Examples of wired communication media include Ethernet, USB, and RS-232. Alternatively communication media may be wireless including radio frequency (RF) and optical. The glucose measurement device may have one or more slots for fluid processing devices such as test strips discussed above. Networked devices can be particularly useful in some situations. For example, networked devices that provide blood glucose monitoring results to a care provider (such as a doctor) can facilitate background analysis of compliance of a diabetic with diet, medication and insulin regimes which could then trigger earlier intervention by a healthcare provider when results begin trending in a clinically undesirable direction. Additionally, automatic messages in response to sample measurements can be generated to either the patient monitoring their glucose level and/or to the care provider. In some instances, automatic messages may be generated by the system to either encourage behavior (e.g., a text message or email indicating a patient is on track) or discourage behavior (e.g., a text message or email indicating that sugars are trending upward). Other automated messages could be either email or text messages providing pointers and tips for managing blood sugar. The networked communication system therefore enables background health monitoring and early intervention which can be achieved at a low cost with the least burden to health care practitioners. Additionally, live chat or texting can be facilitated via the mobile device to enable a care provider to intervene with a user real time in response to a recent communication. The user can easily review the results on the glucose measurement device while communicating with the care giver, or other person, on the wireless communication device. [0038] To further appreciate the networked configurations of multiple glucose measurement device in a communication network, FIG. 5A is a block diagram showing a representative example logic device through which a browser can be accessed to control and/or communication with glucose measurement device described above. A computer system (or digital device) 500 , which may be understood as a logic apparatus adapted and configured to read instructions from computer readable storage media 514 which is configured to tangibly store thereon computer readable instructions and/or network port 506 , is connectable to a server 510 , and has a fixed media 516 . The computer system 500 can also be connected to the Internet or an intranet. The system includes central processing unit (CPU) 502 , disk drives 504 , optional input devices, illustrated as keyboard 518 and/or mouse 520 and optional monitor 508 . Data communication can be achieved through, for example, communication medium 509 to a server 510 at a local or a remote location. The communication medium 509 can include any suitable means or mechanism of transmitting and/or receiving data. For example, the communication medium can be a network connection, a wireless connection, or an internet connection. It is envisioned that data relating to the use, operation or function of the one or more glucose measurement devices (shown together for purposes of illustration here as 560 ) can be transmitted over such networks or connections. The computer system can be adapted to communicate with a user (users include healthcare providers, physicians, lab technicians, nurses, nurse practitioners, patients, and any other person or entity which would have access to information generated by the system) and/or a device used by a user. The computer system is adaptable to communicate with other computers over the Internet, or with computers via a server. Moreover the system is configurable to activate one or more devices associated with the network (e.g., diagnostic devices and/or glucose measurement device) and to communicate status and/or results of tests performed by the devices and/or systems. [0039] As is well understood by those skilled in the art, the Internet is a worldwide network of computer networks. Today, the Internet is a public and self-sustaining network that is available to many millions of users. The Internet uses a set of communication protocols called TCP/IP (i.e., Transmission Control Protocol/Internet Protocol) to connect hosts. The Internet has a communications infrastructure known as the Internet backbone. Access to the Internet backbone is largely controlled by Internet Service Providers (ISPs) that resell access to corporations and individuals. [0040] The Internet Protocol (IP) enables data to be sent from one device (e.g., a phone, a Personal Digital Assistant (PDA), a computer, etc.) to another device on a network. There are a variety of versions of IP today, including, e.g., IPv4, IPv6, etc. Other IPs are no doubt available and will continue to become available in the future, any of which can, in a communication network adapted and configured to employ or communicate with one or more glucose measurement devices, be used without departing from the scope of the disclosure. Each host device on the network has at least one IP address that is its own unique identifier and acts as a connectionless protocol. The connection between end points during a communication is not continuous. When a user sends or receives data or messages, the data or messages are divided into components known as packets. Every packet is treated as an independent unit of data and routed to its final destination—but not necessarily via the same path. [0041] The Open System Interconnection (OSI) model was established to standardize transmission between points over the Internet or other networks. The OSI model separates the communications processes between two points in a network into seven stacked layers, with each layer adding its own set of functions. Each device handles a message so that there is a downward flow through each layer at a sending end point and an upward flow through the layers at a receiving end point. The programming and/or hardware that provides the seven layers of function is typically a combination of device operating systems, application software, TCP/IP and/or other transport and network protocols, and other software and hardware. [0042] Typically, the top four layers are used when a message passes from or to a user and the bottom three layers are used when a message passes through a device (e.g., an IP host device). An IP host is any device on the network that is capable of transmitting and receiving IP packets, such as a server, a router or a workstation. Messages destined for some other host are not passed up to the upper layers but are forwarded to the other host. The layers of the OSI model are listed below. Layer 7 (i.e., the application layer) is a layer at which, e.g., communication partners are identified, quality of service is identified, user authentication and privacy are considered, constraints on data syntax are identified, etc. Layer 6 (i.e., the presentation layer) is a layer that, e.g., converts incoming and outgoing data from one presentation format to another, etc. Layer 5 (i.e., the session layer) is a layer that, e.g., sets up, coordinates, and terminates conversations, exchanges and dialogs between the applications, etc. Layer- 4 (i.e., the transport layer) is a layer that, e.g., manages end-to-end control and error-checking, etc. Layer- 3 (i.e., the network layer) is a layer that, e.g., handles routing and forwarding, etc. Layer- 2 (i.e., the data-link layer) is a layer that, e.g., provides synchronization for the physical level, does bit-stuffing and furnishes transmission protocol knowledge and management, etc. The Institute of Electrical and Electronics Engineers (IEEE) sub-divides the data-link layer into two further sub-layers, the MAC (Media Access Control) layer that controls the data transfer to and from the physical layer and the LLC (Logical Link Control) layer that interfaces with the network layer and interprets commands and performs error recovery. Layer 1 (i.e., the physical layer) is a layer that, e.g., conveys the bit stream through the network at the physical level. The IEEE sub-divides the physical layer into the PLCP (Physical Layer Convergence Procedure) sub-layer and the PMD (Physical Medium Dependent) sub-layer. [0043] Wireless networks can incorporate a variety of types of mobile devices, such as, e.g., cellular and wireless telephones, PCs (personal computers), laptop computers, tablet computers, wearable computers, cordless phones, pagers, headsets, printers, PDAs, etc. and suitable for use in a system or communication network that includes one or more glucose measurement devices. For example, mobile devices may include digital systems to secure fast wireless transmissions of voice and/or data. Typical mobile devices include some or all of the following components: a transceiver (for example a transmitter and a receiver, including a single chip transceiver with an integrated transmitter, receiver and, if desired, other functions); an antenna; a processor; display; one or more audio transducers (for example, a speaker or a microphone as in devices for audio communications); electromagnetic data storage (such as ROM, RAM, digital data storage, etc., such as in devices where data processing is provided); memory; flash memory; and/or a full chip set or integrated circuit; interfaces (such as universal serial bus (USB), coder-decoder (CODEC), universal asynchronous receiver-transmitter (UART), phase-change memory (PCM), etc.). Other components can be provided without departing from the scope of the disclosure. [0044] Wireless LANs (WLANs) in which a mobile user can connect to a local area network (LAN) through a wireless connection may be employed for wireless communications between one or more glucose measurement devices. Wireless communications can include communications that propagate via electromagnetic waves, such as light, infrared, radio, and microwave. There are a variety of WLAN standards that currently exist, such as Bluetooth®, IEEE 802.11, and the obsolete HomeRF. [0045] By way of example, Bluetooth products may be used to provide links between mobile computers, mobile phones, portable handheld devices, personal digital assistants (PDAs), and other mobile devices and connectivity to the Internet. Bluetooth is a computing and telecommunications industry specification that details how mobile devices can easily interconnect with each other and with non-mobile devices using a short-range wireless connection. Bluetooth creates a digital wireless protocol to address end-user problems arising from the proliferation of various mobile devices that need to keep data synchronized and consistent from one device to another, thereby allowing equipment from different vendors to work seamlessly together. [0046] An IEEE standard, IEEE 802.11, specifies technologies for wireless LANs and devices. Using 802.11, wireless networking may be accomplished with each single base station supporting several devices. In some examples, devices may come pre-equipped with wireless hardware or a user may install a separate piece of hardware, such as a card, that may include an antenna. By way of example, devices used in 802.11 typically include three notable elements, whether or not the device is an access point (AP), a mobile station (STA), a bridge, a personal computing memory card International Association (PCMCIA) card (or PC card) or another device: a radio transceiver; an antenna; and a MAC (Media Access Control) layer that controls packet flow between points in a network. [0047] In addition, Multiple Interface Devices (MIDs) may be utilized in some wireless networks. MIDs may contain two independent network interfaces, such as a Bluetooth interface and an 802.11 interface, thus allowing the MID to participate on two separate networks as well as to interface with Bluetooth devices. The MID may have an IP address and a common IP (network) name associated with the IP address. [0048] Wireless network devices may include, but are not limited to Bluetooth devices, WiMAX (Worldwide Interoperability for Microwave Access), Multiple Interface Devices (MIDs), 802.11x devices (IEEE 802.11 devices including, 802.11a, 802.11b and 802.11g devices), HomeRF (Home Radio Frequency) devices, Wi-Fi (Wireless Fidelity) devices, GPRS (General Packet Radio Service) devices, 3 G cellular devices, 2.5 G cellular devices, GSM (Global System for Mobile Communications) devices, EDGE (Enhanced Data for GSM Evolution) devices, TDMA type (Time Division Multiple Access) devices, or CDMA type (Code Division Multiple Access) devices, including CDMA2000. Each network device may contain addresses of varying types including but not limited to an IP address, a Bluetooth Device Address, a Bluetooth Common Name, a Bluetooth IP address, a Bluetooth IP Common Name, an 802.11 IP Address, an 802.11 IP common Name, or an IEEE MAC address. [0049] Wireless networks can also involve methods and protocols found in, Mobile IP (Internet Protocol) systems, in PCS systems, and in other mobile network systems. With respect to Mobile IP, this involves a standard communications protocol created by the Internet Engineering Task Force (IETF). With Mobile IP, mobile device users can move across networks while maintaining their IP Address assigned once. See Request for Comments (RFC) 3344. NB: RFCs are formal documents of the Internet Engineering Task Force (IETF). Mobile IP enhances Internet Protocol (IP) and adds a mechanism to forward Internet traffic to mobile devices when connecting outside their home network. Mobile IP assigns each mobile node a home address on its home network and a care-of-address (CoA) that identifies the current location of the device within a network and its subnets. When a device is moved to a different network, it receives a new care-of address. A mobility agent on the home network can associate each home address with its care-of address. The mobile node can send the home agent a binding update each time it changes its care-of address using Internet Control Message Protocol (ICMP). [0050] In basic IP routing (e.g., outside mobile IP), routing mechanisms rely on the assumptions that each network node always has a constant attachment point to the Internet and that each node's IP address identifies the network link it is attached to. Nodes include a connection point, which can include a redistribution point or an end point for data transmissions, and which can recognize, process and/or forward communications to other nodes. For example, Internet routers can look at an IP address prefix or the like identifying a device's network. Then, at a network level, routers can look at a set of bits identifying a particular subnet. Then, at a subnet level, routers can look at a set of bits identifying a particular device. With typical mobile IP communications, if a user disconnects a mobile device from the Internet and tries to reconnect it at a new subnet, then the device has to be reconfigured with a new IP address, a proper netmask and a default router. Otherwise, routing protocols would not be able to deliver the packets properly. [0051] Computing system 500 , described above, can be deployed as part of a computer network that includes one or devices 560 , such as glucose measurement devices disclosed herein. In general, the description for computing environments applies to both server computers and client computers deployed in a network environment. FIG. 5B illustrates an exemplary illustrative networked computing environment 500 , with a server in communication with client computers via a communications network 550 . As shown in FIG. 5B , server 510 may be interconnected via a communications network 550 (which may be either of, or a combination of a fixed-wire or wireless LAN, WAN, intranet, extranet, peer-to-peer network, virtual private network, the Internet, or other communications network) with a number of client computing environments such as tablet personal computer 502 , mobile telephone 504 , telephone 506 , personal computer 502 ′, and personal digital assistant 508 . In a network environment in which the communications network 550 is the Internet, for example, server 510 can be dedicated computing environment servers operable to process and communicate data to and from client computing environments via any of a number of known protocols, such as, hypertext transfer protocol (HTTP), file transfer protocol (FTP), simple object access protocol (SOAP), or wireless application protocol (WAP). Other wireless protocols can be used without departing from the scope of the disclosure, including, for example Wireless Markup Language (WML), DoCoMo i-mode (used, for example, in Japan) and XHTML Basic. Additionally, networked computing environment 500 can utilize various data security protocols such as secured socket layer (SSL) or pretty good privacy (PGP). Each client computing environment can be equipped with operating system 538 operable to support one or more computing applications, such as a web browser (not shown), or other graphical user interface (not shown), or a mobile desktop environment (not shown) to gain access to server computing environment 500 . [0052] In operation, a user (not shown) may interact with a computing application running on a client computing environment to obtain desired data and/or computing applications. The data and/or computing applications may be stored on server computing environment 500 and communicated to cooperating users through client computing environments over exemplary communications network 550 . A participating user may request access to specific data and applications housed in whole or in part on server computing environment 500 . These data may be communicated between client computing environments and server computing environments for processing and storage. Server computing environment 500 may host computing applications, processes and applets for the generation, authentication, encryption, and communication data and applications and may cooperate with other server computing environments (not shown), third party service providers (not shown), network attached storage (NAS) and storage area networks (SAN) to realize application/data transactions. [0053] V. KITS [0054] Bundling all devices, tools, components, materials, and accessories needed to use a measurement device to test a sample into a kit may enhance the usability and convenience of the devices. Suitable kits for glucose measurement can also include, for example, power source; test strips; wireless communication apparatus; and a glucose measurement device. VI. EXAMPLES Example 1 [0055] In some configurations, the module adaptor can be configured to connect to standard 3 conductor (or two, or more) electrochemical glucose sensor strip, and simply passes the connection through the interface with minimal circuitry or processing. The handheld device connected to the module electronically monitors the signal, and the glucose application within the handheld device contains the glucose calculation engine to convert the measured voltages/currents into a blood glucose result. The adaptor could be self powered by a rechargeable battery (e.g., from its handheld device connection) or replaceable internal battery, or could simply derive power solely off handheld device connection power. Example 2 [0056] In some configurations, the adapter or module itself can be configured to contain circuitry and software to power and monitor a sensor strip, and to calculate a glucose result internally before transferring this result to the handheld device. This offers some advantages in terms of completely controlling the glucose calculation, to help ensure that future changes to the handheld device or their glucose applications will not interfere with calculating a correct glucose result as detected by the adapter. Such a configuration could be configured such that it is powered by rechargeable or replaceable battery, or, as described above, off the handheld device. Moreover, permanent memory resident to the adapter could be configured to include firmware. Example 3 [0057] In other configurations, the adaptor or module is configured to calculate glucose values internally as described above for Example 2. Additionally, the adaptor can be configured to provide a small or simple display screen that can be used to compare/confirm the result as reported by handheld device. Also has the advantage of being a tiny stand-alone meter that can be used either attached or detached from the handheld device. For detachable use, the device would be configured to include a rechargeable or replaceable battery. However, it could also be powered off of the handheld device when it is in an attached configuration. Memory can also be provided for storing one or multiple glucose results. Stored results can then be uploaded to the handheld device in a separate step when the device is connected to a handheld device. In most configurations, the handheld device is capable of any level of complexity in glucose data reporting and storage, including simply reporting the current result in large, easy to read format, storing multiple results for later review, graphing, and otherwise trending and reporting results, and transmitting any or all of these and more to a central service or physician. [0058] Advantages of the adapter include flexibility. As new applications come out, new data management features can be introduced. Unlike current fully integrated glucose monitoring cell phones, the adaptor module is detachable, transferable, and replaceable without purchasing a new handheld device. [0059] While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

Module adaptable to communicate with a suitable handheld devices or PDAs. Suitable devices include, but are not limited to, the Apple iPhone® or iPod®, Research in Motion Blackberry® smart phones, Motorola Droid smart phones, and Palm Pre smart phones. The module can be used without adding to the cost of the handheld device. This allows direct reimbursement for the replaceable meter module portion if payers choose to limit coverage for the full system, as well as the possibility of reimbursement for the entire system including the handheld device. Other solutions build the cost into the phone, which must be replaced to upgrade or replace the glucose function. Moreover, information from the glucose meter reading can be communicated from the PDA to a remote station for reporting the results. With an iPod-like approach, this could be accomplished without the need for a cellular signal or carrier, as long as a WiFi internet connection is available anywhere in the world.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to fabrication of an optical fiber preform. More specifically, the present invention relates to removing soot particles and controlling the diameter of the preform during a chemical vapor deposition (CVD) process. [0003] 2. Description of the Related Art [0004] The present invention is useable with a process for manufacturing a preform from which optical fibers may be drawn. Such optical fibers are used for transmitting optical signals in telecommunications applications. The preform may be manufactured by a variety of methods, including the CVD process in which glassy particles (soot) are deposited onto the inside wall of a glass substrate tube. The soot generally comprises silica that has been doped to provide a desired index of refraction. During the deposition process the soot is passed longitudinally through the glass tube by a carrier gas and a heat source is passed over the outside of the glass tube. The heat from the heat source sinters the soot to provide a homogenous glass layer. Heating the tube softens the tube and the pressure must be controlled inside the tube to achieve a desired tube diameter. Without a constant target pressure, the tube diameter may detrimentally increase, decrease, or otherwise deform, thereby affecting the quality of the preform and the resulting fibers drawn from the preform. [0005] Methods for controlling the pressure inside the tube are currently unsatisfactory. For example, known methods of controlling the pressure inside the tube include using a valve to control the flow of the soot and carrier gas, and introducing a counterflow of a gas, such as oxygen, nitrogen, or other inert gas, at a downstream position relative to the flow of soot. In either example, a back-pressure is thereby created in the tube. However, such prior art methods suffer from several drawbacks including, for example, “blowback” caused by the valve sticking in a “closed” position, or imbalances that develop between the tube inlet and exit pressures. Specifically, the valve may become clogged with soot and is prevented from opening properly, some other obstruction within the apparatus may develop, or the counterflow gas may “spike” due to an unintended control loop command. Regardless of the cause, the pressure imbalance must eventually correct itself, often to the detriment of the preform. Short-term imbalances such as those described above can result in large soot agglomerations being propelled backwards into the substrate tube. These instances of blow-back cause imperfections, such as bubbles, that reduce the quality of the preform. Long-term pressure imbalances can cause catastrophic failures if the over-pressurization persists for a sufficient amount of time to cause the preform to burst. [0006] In view of the preceding discussion, a need exists for an apparatus and method for controlling the pressure in the glass substrate tube without causing imperfections or preform bursting during a CVD process. ASPECTS OF THE INVENTION [0007] In a first aspect of the present invention an optical fiber preform fabricating device is provided. The preform fabricating device includes a particle remover for removing soot from a carrier gas, the soot being particles that are not deposited on a substrate tube. A soot collector communicates with the particle remover and contains the soot removed by the particle remover. Further, a control valve communicates with the particle remover. The control valve adjusts a pressure within the substrate tube. [0008] In a second aspect of the present invention an optical fiber preform fabricating device is provided. The preform fabricating device includes a particle remover, a collector and a valve. The particle remover removes soot from a carrier gas, the soot being particles that are not deposited on a substrate tube. The collector communicates with the particle remover and contains the soot removed by the particle remover. The valve adjusts a pressure within the substrate tube. [0009] In another aspect of the present invention, a method for fabricating a preform is provided. The method includes the step of removing soot from a carrier gas before the carrier gas passes through a valve, the soot being particles that are not deposited on a substrate tube. The method also includes the step of controlling a pressure and a flow rate of the carrier gas within the substrate tube. [0010] These and other aspects, features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0011] [0011]FIG. 1 is a plan view of a preferred embodiment of the present invention. [0012] [0012]FIG. 2 is a plan view of features of the preferred embodiment of the present invention. [0013] [0013]FIG. 3 is a cross-sectional view of a glass tube during a CVD operation. DETAILED DESCRIPTION OF THE INVENTION [0014] As explained below in detail, preferred embodiments of the present invention provide an apparatus and method for removing soot particles from a carrier gas and for controlling the diameter of a glass substrate tube during a CVD process. Of course the invention should not be limited solely to such features. These and other features of the preferred embodiments of the present invention are discussed below in detail. [0015] A deposition apparatus 10 for performing a CVD operation in accordance with the present invention is illustrated in FIG. 1. The deposition apparatus 10 includes a glass working lathe 12 having a headstock 14 and a tailstock 16 . The headstock 14 and tailstock 16 support a substrate tube 18 in such a manner that the substrate tube 18 may be rotated about its longitudinal axis. The substrate tube 18 is mounted in the headstock 14 and tailstock 16 such that a stream of reactants, collectively referred to as soot, entrained in a carrier gas passes longitudinally through the substrate tube 18 . Specifically, the reactants and the carrier gas are fed through the headstock 14 , they react and form soot particles in the substrate tube 18 , and the effluent, which includes carrier gasses and undeposited soot, flows through the tail stock 16 . The soot includes dopants, such as germanium, for affecting optical properties of the finished preform. In a preferred embodiment the soot may also include phosphorous, fluorine, or any other desired materials. [0016] The glass working lathe 12 also includes a heat source 20 such as a hydrogen and oxygen burner that directs heat against the substrate tube 18 in a defined heated area. The heated area creates a reaction zone within the substrate tube 18 . The heat source 20 is moved co-axially along the rotating substrate tube 18 during the CVD process, thereby causing the reaction zone to move along the substrate tube 18 . Soot is deposited onto the inner surface of the substrate tube 18 within and downstream of the reaction zone and is fused into a homogenous layer by the heat from the heat source 20 . Moving the heat source 20 along the substrate tube 18 is repeated one or more times to deposit additional layers of soot onto the inner wall of the substrate tube 18 . The wall of the substrate tube 18 is thereby increased to a desired thickness. See FIG. 3. [0017] Not all of the soot is deposited onto the wall of the substrate tube 18 when the soot and carrier gas mixture passes through the reaction zone. The remaining soot and carrier gas mixture exits the substrate tube 18 through the tailstock 16 . As shown in FIGS. 1 and 2, the soot and gas mixture passes through the tailstock 16 and enters a particle removing device 22 for removing the soot particles from the gas stream. Soot particles are thereby prevented from passing back into the substrate tube 18 if there is any inadvertent counterflow of the carrier gas. The particle removing device 22 may be any suitable mechanism for removing the soot particles. Examples of such a device include separators such as a cyclone, impaction box, impingement separator, filter, scrubber, thermal separator or a settling chamber. In a preferred embodiment, a soot collector 24 communicates with the particle removing device 22 and collects the soot particles for later disposal or recycling. The soot collector 24 may be configured as a removable drawer, a bag or box, or any other easily replaceable or easily cleanable structure. Of course the invention is not limited to the above-described structures, and other devices for separating and holding the soot particles are also considered to be within the scope of the present invention. [0018] In the preferred embodiment, the gas stream exits the particle removing device 22 then passes across a pressure transducer 26 . The pressure transducer 26 may be any known pressure transducer. The pressure transducer 26 detects the pressure of the carrier gas as it exits the particle removing device 22 and, from this detected pressure, the pressure inside the substrate tube 18 may be closely approximated. The position shown in FIGS. 1 and 2 for pressure transducer 26 is only one example. Other ports for pressure measurement can be placed at various points within the system. Also, for increased accuracy, multiple pressure transducers 26 may be used to detect the pressure at multiple points within the deposition apparatus 10 . For example, a pressure transducer 26 may be incorporated into one or more of the particle removing device 22 , the tailstock 16 and the headstock 14 . The pressure within the substrate tube 18 may thus be accurately approximated in accordance with measurements from one or more of the pressure transducers 26 . [0019] As shown in FIG. 2, the carrier gas passes through a control valve 28 after passing across the pressure transducer 26 . The control valve 28 controls the flow rate of the gas stream as the gas stream passes through the deposition apparatus 10 and thereby controls the gas pressure inside the substrate tube 18 . Specifically, the control valve 28 is adjusted by a controller 30 to regulate the flow rate of the gas in accordance with the pressure detected by the pressure transducer 26 . By way of example, the controller 30 may include a central processing unit and memory with executable code for manipulating data received from the pressure transducer 26 and for outputting a corresponding control signal to the control valve 28 . The control valve 28 may be any conventional pressure proportioning or flow control valve assembly, or any other variable aperture device useable for regulating the flow of gas and/or pressure in response to a control signal or other input. The controller 30 controls the control valve 28 such that the pressure of the carrier gas inside substrate tube 18 reaches and maintains a desired value. The pressure of the carrier gas in the substrate tube 18 is decreased by controlling the control valve 28 to adjust to a more open position. The flow rate of the carrier gas through the control valve 28 and out of the substrate tube 18 is thereby increased, and the pressure within the substrate tube 18 is decreased. Alternatively, the pressure of the carrier gas in the substrate tube 18 is increased by controlling the control valve 28 to adjust to a more closed position. The flow rate of the carrier gas through the control valve 28 and out of the substrate tube 18 is thereby decreased, and the pressure within the substrate tube 18 increases. In accordance with a preferred embodiment of the present invention, the control valve 28 does not suffer performance degradation caused by soot accretion. Instead, the particle removing device 22 removes the soot from the carrier gas before the carrier gas enters the control valve 28 , and the control valve 28 is thus protected from becoming clogged or fouled. Blow-back of gas into the substrate tube 18 resulting from the control valve 28 sticking in the closed position, leading to an imbalance in gas pressures, is thereby prevented. If more than one pressure transducer 26 is used to monitor pressures within the deposition apparatus 10 , the controller 30 adjusts the control valve 28 in accordance with the pressures detected by each of the pressure transducers 26 , or by pre-determined combinations of the pressure transducers 26 . [0020] The gas stream exits the control valve 28 and passes to downstream components such as a scrubber 32 for further removing components from the carrier gas. For example, the scrubber 32 removes any remaining particles, chlorine gases, germanium, silica, byproducts of reactions in the reaction zone, or any other predetermined components of the carrier gas. [0021] As described above in detail, a preferred embodiment of the present invention prevents fouling of the control valve 28 , and prevents blow-back of the carrier gas and soot into the substrate tube 18 . In addition to preventing fouling and blow-back, a preferred embodiment of the present invention also controls the diameter of the substrate tube 18 . Specifically, the wall of the substrate tube 18 in the reaction zone is softened when the wall is heated by the heat source 20 . The pressure of the carrier gas is detected by one or more of the pressure transducers 26 and the pressure within the reaction zone of the substrate tube 18 is approximated. The controller 30 then controls the control valve 28 to increase or decrease the flow rate of the carrier gas through the substrate tube 18 in accordance with the pressure detected by the pressure transducer. The difference in pressure between the carrier gas in the substrate tube 18 and ambient pressure outside the substrate tube 18 causes the softened walls of the substrate tube 18 to expand or collapse to reach a desired diameter. Further, unwanted and potentially dangerous expansion of the substrate tube 18 resulting from obstructions caused by soot build-up in the exhaust apparatus is prevented in the manner previously discussed. Specifically, the control valve 28 is prevented from becoming fouled, and an unwanted pressure differential does not occur, because the particle removing device 22 removes unwanted soot particles from the carrier gas stream before the carrier gas stream passes through the control valve 28 . In the foregoing manner the diameter of the substrate tube 18 in the reaction zone is reliably controlled. As the heat source 20 moves along the substrate tube 18 the reaction zone also moves along the substrate tube 18 . The diameter of the entire substrate tube 18 is then controlled in the foregoing manner. [0022] Although specific embodiments of the present invention have been described above in detail, it will be understood that this description is merely for illustration purposes. Various modifications of and equivalent structures corresponding to the disclosed aspects of the preferred embodiments in addition to those described above may be made by those skilled in the art without departing from the spirit of the present invention which is defined in the following claims, the scope of which is to be accorded the broadest interpretation so as to encompass such modifications and equivalent structures.

An optical fiber preform fabricating device is disclosed. The device includes a particle remover for removing soot from a carrier gas, the soot being particles that are not deposited on a substrate tube. The device also includes a soot collector communicating with the particle remover for containing the soot removed by the particle remover. A control valve communicates with the particle remover, and adjusts a pressure within the substrate tube.

CROSS-REFERENCE TO RELATED APPLICATION This application is a United States national phase application of co-pending international patent application number PCT/SI2011/000030, filed Jun. 2, 2011, which claims the benefit of Slovenia Application No. P-201000257 filed Aug. 26, 2010, of which is hereby incorporated by reference in its entirety. BACKGROUND The invention refers so a varistor fuse element, which comprises at least a varistor and a melting member and can be integrated into each appropriate DC or AC electric circuit. According to the International Patent Classification, such inventions belong to electricity, namely to basic electric elements, in particular to overvoltage protection components on the basis of varistors. Furthermore, such invention may also belong to emergency protective circuit arrangements, which are adapted to interrupt the circuit automatically, as soon as undesired deviations with respect to usual operating conditions occur and/or when transient voltage occurs. The invention is rest on the problem how to arrange a varistor fuse element comprising a combination of a varistor and a melting member that in a simple manner and when possible without introducing additional parts, components and wirings an efficient overvoltage protection will be maintained despite to possible variations of resistance if/whenever these would occur. Consequently, the purpose of the invention is to create such a fuse, which should in a single and uniform casing comprise a varistor part, which should be capable to protect electric installations against overvoltage impulses and current strokes, as well as an electric fuse, which should be capable to transmit the current stroke due to increased voltage and to interrupt the circuit in the case of permanently increased current, which might occur due to damages in the varistor part. At the same time, such fuse element be available in the form of commonly used protective appliances, in particular electric melting fuses, and should not exceed dimensions thereof. A varistor fuse element is one of protective appliances, which are intended for integration into electric circuits, in particular such circuits in which the probability of generating transient or transitional voltage due to direct or indirect lightning strike into particular building or its surrounding is pretty high. Such varistor fuse element may be used both in AC or DC installations, and also in electric installations used in exploitation of renewable energy resources, for example in photovoltaic power plants. Protection against overvoltage, namely protection against short-term overvoltage impulses, is generally known to those skilled in the art and is a standard part in a sequence of protective measures in low-voltage electric installations. Namely, a voltage-depending resistance, the so-called varistor is usually used for such purposes. Varistors are usually manufactured in the form of plates consisting of a special sintered material, e.g. of zinc oxide (ZnO). Thanks to their properties, in normal circumstances the resistance thereof is very high. When exposed to an overvoltage impulse, e.g. due to a lightning strike, the resistance of such varistor is essentially decreasing, and the undesired overvoltage stroke is transmitted to the earth. Upon that, the resistance is increasing again towards the range of electric insulators. As known, upon several successive current strokes through the varistor problems may occur in regard of changing the resistance of the varistor. By such changing, certain lower currents may be generated within the resistor even by nominal voltage. Such currents lead to overheating of the resistor, which results in further damages within the resistor, until it becomes completely out of order. Of that reason the varistor is normally serial connected with a thermal switch, which is able to operate in such a manner that by to high temperature on the body of the varistor the last is separated out from the circuit. Such thermal switch is usually manufactured in the form of resilient strip, which is soldered onto the varistor body. As soon as the body is then overheated due to current conducted by the nominal voltage, the solder is molten and the circuit is then interrupted by means of such switch. The main deficiency of such switch is the arc, which may occur in such switch and cannot be managed by the switch, which may be quite dangerous in photovoltaic (PV) installations. In such cases the explosion may occur in the switch, by which a part of installation may be damaged or at risk. The situation with said PV installations is in particular problematic because the parallel arc cannot be extinguished until the panel is exposed to the light. Said problem is not just a hypothetic one, and the users have complained that at present available overvoltage protection in PV installations is definitively bound with such problems. Several approaches in the course of resolving such problems are known in the prior art. The fist possibility is given by the so-called SRF fuse (Surge Rated Fuse), which is serial connected to the varistor and is merely dealing with the question of essentially decreased resistance, through which a short circuit may occur at the nominal voltage. However, the melting threshold of such SRF fuse must be pre-determined at sufficiently high level since otherwise the fuse would be molten whenever the current stroke would occur. Consequently, the fuse is declared with regard to each value kA of impulse, which may still be conducted through such SRF fuse. The main deficiency of such approach results in two separate parts within two separate casings, namely a varistor within its casing and serial SRF fuse in its casing or stand, which have to be integrated installation. Such approach then requires much more space and wirings, which is undesired. A further approach is described in WO2008/69870 (Ferraz Shawmut). In this case, the varistor is serial interconnected with a thermal switch, which is parallel interconnected with a fuse. A resilient strip of the thermal switch is soldered onto the varistor. When by too high temperature of the varistor the switch is activated, the current is redirected towards the fuse, in which the melting member is then molten, and the arc is herewith extinguished. Such appliance consists of three parts, which is a main deficiency, and moreover, two processes are successively performed, wherein in the first step the solder is molten on the contact of the switch, by which the switch is activated, and upon that in the second step the melting member within the fuse must be molten. A still further approach is described in WO2004/072992 where the tubular varistor is foreseen, which simultaneously serves as a casing for a fuse having a melting member. However, when the overvoltage occurs, the casing of such fuse cannot serve as a resistance anymore, since the varistor becomes conductive at least for a short time period, so that the melting member of such fuse is then unable to perform correctly the main function thereof. Of that reason, at least according to the knowledge of the present inventor, this solution has never been practically applied. It is moreover known to those skilled in the art that a so-called M-effect is performed for the purposes of interrupting each melting member whenever to high current has occurred, which might lead to overloading of installations. Such effect is based on the fact that the melting temperature of a copper-tin alloy is lower than the melting temperature of each of these metals as such. From quite construction point of view, melting members in fuses are manufactured in such a manner that the tin in the form of solder is placed on a copper melting member adjacent to a weak portion which is also foreseen on such melting member. When exposed to sufficiently high current, the temperature of the weak portion is increased, which leads to melting of tin within the solder, wherein said copper-tin alloy has not only a lower melting temperature but also higher electric resistance. Consequently, the resistance of the melting member in the area of said weak portion is increased, which leads to still further heating of the solder and still more intensive producing the copper-tin alloy. The whole process is developed quickly up to interruption of the melting member in the area of said weak portion. Operation of melting fuses and melting members is described in literature relating to operation and exploitation of such fuses. SUMMARY The invention refers to a varistor fuse element, comprising a cylindrical varistor, the resistance of which depends on voltage, as well as a cylindrical fuse, which are serial electric connected to each other. Said varistor consists of a pair of electric conductive electrodes, which are separated from each other by means of a body consisting of a material having a resistance which is depending on electric voltage, while said fuse consists of an electric insulating body, which is furnished with contact means which consist of an electric conductive material and are located on the end portions thereof and connected to each other by means of a melting member, which consists of electric conductive material and is furnished with a weak portion having a pre-determined cross-section which is adjusted for the purpose of melting and interrupting the contact between said contact means when the fuse is electrically overloaded. In this case the invention provides that the fuse comprising a round tubular body and a varistor also comprising round tubular body are inserted within each other in such a manner that the varistor is placed within a longitudinal passage in the body of the fuse which is filled with the arc extinguishing material, and that electric conductive contact means are available on the end portions of said fuse body, wherein the electrode on the external surface of the varistor is electrically interconnected with one contact means of the fuse, while the other contact means thereof is via the melting member electrically interconnected with the other electrode of the varistor, which is available on the internal surface of the body of said varistor. Another aspect of the invention refers to a varistor fuse element, comprising a cylindrical varistor, having the resistance which depends on voltage, as well as a cylindrical fuse, which are electric interconnected in a serial manner, wherein said varistor consists of a pair of electric conductive electrodes, which are separated from each other by a body consisting of a material having a resistance which is depending on electric voltage, and wherein said fuse consists of an electric insulating body, which is furnished with electric conductive contact means which are located on the end portions thereof and are connected to each other by means of a melting member, which consists of electric conductive material and comprises a weak portion having a pre-determined cross-section which is adjusted for the purposes of melting and interrupting the contact between said contact means when the fuse is electrically overloaded. In this case the invention provides that the fuse comprising a round tubular body and the varistor also comprising a round tubular body are inserted within each other, so that the fuse is inserted within a longitudinal passage in the round tubular body of said varistor comprising the first electrode placed on the external surface and at least partially on one of the front surface thereof, while the second electrode of the varistor is located on the internal surface of said varistor body, wherein said fuse is exposed to the heat generated within the varistor due to varying the resistance thereof and comprises a longitudinal passage which is filled with an arc extinguishing material as well as melting member which extends throughout said passage and by means of which two contact means arranged on the end portions of the fuse are connected to each other indirectly via appropriate solder, and wherein the first contact means of the fuse is arranged within said passage in the body of the varistor and is electrically interconnected with the electrode on the internal surface of the body of the varistor, while the second contact means is arranged outside of the passage of the body of the varistor and is included in the electric circuit together with the other electrode located on the external surface and/or the front surface of the body of the varistor. Said melting member comprises at least one weak portion having a pre-determined transversal cross-section. In accordance with the first aspect of the invention, the melting member is via the solder electrically connected to the second electrode of the varistor, which is located on the internal surface of the body of the varistor. The weak portion on the melting member is preferably located adjacent to the solder. Moreover, said second electrode of the varistor and the melting member are both interconnected i.e. coated with the colder until the last is molten. The melting member is preferably pre-tensioned prior to coating thereof by solder and has a tendency of deflecting apart from the electrode of the varistor. In general, the invention also provides that the melting temperature of the solder is lower than the melting temperatures of materials of the melting member and of the electrode of the varistor cooperating therewith. The material of the solder is preferably defined in such a manner that the resistance thereof is increasing by increasing the temperature. Moreover, the arc extinguishing material, which is present within the passage of the fuse and preferably also within the passage of the varistor, is preferably silica. BRIEF DESCRIPTION OF THE DRAWINGS The invention is described in more detail on the basis of two embodiments, which are shown in the attached drawing, wherein FIG. 1 is a longitudinal cross-section through the first embodiment; and FIG. 2 is a longitudinal cross-section through the second embodiment. DETAILED DESCRIPTION The object of the invention is a construction concept of product, by which the previously exposed problem has been resolved. The proposed solution is based on a cylindrical fuse 2 and a varistor 1 in the form of a cylindrical tube. Two embodiments of will be described. In both embodiments, said fuse 2 and said varistor are arranged coaxially within each other, wherein in the first embodiment according to FIG. 1 the varistor 1 is placed within the passage of a round tubular body 20 of the fuse 2 , while in the second embodiment on the contrary the fuse 2 is inserted within a passage in a round tubular body 10 of the varistor. In this, the term “round tubular” body 10 of the varistor 1 or “round tubular” body 20 of the fuse 2 means a body in the form of a round tube, namely of a tube having a round transversal cross-section. Said round tubular body 10 of the varistor consists of a material (e.g. of ZnO) by which the conductivity is depending on contact voltage, so that such material may be used as insulator up to a pre-determined value of voltage. As soon as the voltage has overcome such pre-determined value, depending on thickness and configuration, the conductivity is essentially increased, by which the current stroke due to the increased voltage is discharged via the earth connection. In addition to that, due to such cylindrical shape of said body 10 in comparison with commonly used plate-like varistor 1 the complete fuse element as a commercial product is then available in a much more compact form. As known to those skilled in the art, said tubular body 2 of the fuse 2 consists of an insulating material, preferably of ceramics or a plastic composite. Two contact means 21 , 22 are placed on the end portions 23 , 24 of the body 20 and are electrically interconnected via a melting member 25 . The first embodiment according to FIG. 1 is based on a cylindrical fuse 2 having a sufficiently wide internal diameter of the tubular body 20 . (i.e. at least Type CH 22 or larger). In such case, the varistor 1 is manufactured as a cylinder, which is then inserted into a passage of the tubular body 20 of the fuse 2 . A cylindrical varistor 1 is manufactured in such a manner that both electrodes 11 , 12 , which are separated from each other by means of said body 10 of the varistor 1 , are available in the form of silver layers on the external surface 14 and the internal surface 13 of said body 10 , wherein the outer electrode 11 is electrically interconnected with the adjacent first contact means 21 of the fuse 2 , which is in this particular case performed in the area of one of both front surfaces 15 , 16 of the body 10 , while the melting member 25 of the fuse 2 is in this particular case attached to the internal electrode 12 of the varistor 1 by means of a solder 250 and is moreover electrically interconnected with the second contact means 22 of the fuse 2 . Said melting member 25 of the fuse 2 preferably consists of copper and extends throughout the passage in the tubular body 20 of the fuse 2 , which should be normally filled with an arc extinguishing material 26 , in particular with sand on the basis of silica, which is capable to eliminate arc, which might occur when the melting member 25 is interrupted. Said solder 250 preferably consists of an alloy on the basis of copper and tin. The melting member 25 is conceived in such a manner that the first weak portion 25 ′ is located quite in the initial area adjacent to the solder 250 i.e. adjacent to the location of soldering to the electrode 12 of the varistor. Such, the solder 250 is simultaneously used on the one hand for the purposes of establishing of an electric conductive interconnection between the melting member 25 and the electrode 12 of the varistor, and on the other hand also for performing a so-called M-effect, which is required for the purposes of interrupting the melting member 25 in the case of overloading, or by low currents, respectively. The area, in which the solder 250 is applied, is arranged in such a manner that the melting member 25 as such is not in contact with the internal electrode 12 of the varistor 1 which is located on the internal surface 13 of the body 10 , and prior to applying the solder 250 , the melting member 25 is located at certain gap apart from said electrode 12 of the varistor, which gap is then filled with the solder 250 . As soon as the solder 250 is molten, the liquid solder flows out from said gap between the melting member 25 and the electrode 12 of the varistor 1 towards the arc extinguishing material 26 , namely into pores between silica particles. In fact, two processes of interrupting the contact between the melting member 25 and the electrode 12 are actually available and applied simultaneously or separately, depending on each particular conditions related to electric current and temperature. The rest of the melting member 25 outside of said weak portion 25 ′ is conceived in such a manner that the electric circuit throughout the fuse 2 is interrupted as soon as a short-circuit occurs, or when the current is essentially increased. Besides, the melting integral thereof must be sufficiently high, so that quite similarly like in a so-called SRF-fuse, the current stroke of nominal range in kA should not initiate melting of the melting member 25 and interrupt protective effect during the period of such impulse. In this particular case, the complete interior of the fuse 2 and also of the varistor 2 is filled with silica, which is used as the material 26 for extinguishing the arc, which might be generated by when the melting member 25 is interrupted. In accordance with a further aspect of the invention, the melting member 25 is mounted within the fuse 2 in a pre-tensioned state, by which upon melting it is then automatically deflected away from the corresponding electrode 12 of the varistor, so that efficiency and reliability of such varistor fuse element according to invention may be still additionally improved. Whenever an overvoltage impulse occurs, conductivity of the varistor 1 is essentially increasing, so that the current is able to pass the body 10 between the electrodes 11 , 12 radially and then via the melting member 25 , which is however not melting in such situation. Such stroke i.e. overvoltage is then lead to the earth connection. Whenever the varistor 1 is disabled or at least partially damaged, conductivity of the varistor is always increasing, although the overvoltage does not occur at all. Depending on the current intensity, the following possibilities may occur: Whenever a low current of several mA up to approximately 1A is passing through the varistor 1 , the body 10 of the varistor starts overheating, and the solder 250 between the varistor 1 and the melting member 25 starts melting, by which the contact between the electrode 12 of the varistor 1 and the melting member 25 of the fuse 2 is interrupted; whenever the medium current within the range between approx. 1 A and approx. 10A is passing through the varistor 1 , said M-effect occurs in the first weak portion 25 ′ of the melting member 25 , by which the heat is generated both in said weak portion 25 ′ and in the varistor 25 , and interruption is then performed much earlier than in situation without overheating of the varistor 1 ; whenever the current within the range between several hundred A and several kA is passing the varistor 1 , the varistor 1 as such cannot represent a high resistance, while the melting member 25 is held in a short-circuit and is molten across the complete cross-section within a quite short interruption period of several ms. In all three above situations, interruption of the path of the current occurs within the passage in the body 20 of the fuse 2 and therefore in the area where the arc extinguishing material 26 i.e. the silica is present, so that the arc is rapidly extinguished. The fact that the arc can never occur outside of the fuse 2 is apparently an essential benefit in comparison with known solutions, and may simultaneously with a compact construction and combining the fuse 2 with a thermal switch lead to achieving much higher interrupting efficiency of the fuse 2 . Another embodiment according to FIG. 2 is based on a cylindrical varistor 1 , wherein the fuse 2 , e.g. a cylindrical SRF fuse, is embedded within the passage and where the thickness of the wall of the body 10 is determined with regard to each expected level of the voltage. Functioning of the varistor 1 is performed radially through the active body 10 between both electrodes 11 , 12 , and the fuse 2 is serial interconnected with the varistor 1 . Also in this case the varistor 1 and the fuse 2 are arranged coaxially within each other, wherein the fuse 2 is placed within the passage extending throughout the varistor 1 . However, in this case the serial interconnection of the varistor 1 and the fuse 2 is much more conventional. Namely, the melting member 25 is not soldered directly to the electrode 12 like in the first embodiment, and the complete fuse 2 is inserted within the cylindrical varistor 1 . Said M-effect occurs on the melting member 25 in a classic manner like in any other fuse 2 . Whenever the varistor 1 is damaged, the heat generated by such damaged varistor 1 is then via both contact means 21 , 22 and the body 20 of the fuse 2 transferred to the melting member 25 . In this case, the fuse 2 and the varistor 1 , which are inserted within each other, are embedded between contact plates 31 , 32 , which are furnished with contact protrusions 310 , 320 , which are adapted for inserting into not-shown seats for receiving the fuse 2 . The external electrode 11 of the varistor 1 is maintained in the electricity conducting contact with the contact plate 32 on the front surface 16 , while the contact 21 means 21 of the fuse 2 is maintained in the electricity conducting contact with the other contact plate 31 . Electric current between the contact plates 31 , 32 is therefore able to pass through the fuse 2 and through the varistor 1 which is serial interconnected therewith, namely through the contact plate 32 and then through the external electrode 11 as well as the body 10 towards the internal electrode 11 of the varistor 1 , and then via the contact means 22 and the melting member 25 , which is by means of the solder 250 connected thereto, towards the other contact means 21 of the fuse and then through the other contact plate 31 .

The purpose of the invention is to create such a varistor fuse element, which should within a single housing include both a varistor ( 1 ) as well as an electric fuse ( 2 ), wherein said varistor part i.e. a varistor ( 1 ) is intended to protect each electric installation against overvoltage impulses and consequently against current strokes, while the fuse ( 2 ) is capable to transmit the current stroke due to increased voltage and to interrupt each permanently increased electric current, which might occur due to defects on the varistor ( 1 ). Moreover, such varistor fuse should not exceed dimensions of already known and widely used protective means, in particular melting fuses. In accordance with the invention, the fuse ( 2 ) with its round tubular casing ( 20 ) and the varistor, which is also embedded within a round tubular casing ( 10 ), are serial interconnected and arranged coaxially within each other.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a semiconductor device in which electrical connection between a pad of semiconductor chip and an electrode of a circuit substrate is performed via a coil spring. The present invention also relates to a method of manufacturing such semiconductor device. [0003] 2. Description of the Prior Art [0004] In order to comply with increase in processing speed of a semiconductor chip, it has been known and put into practice use that a semiconductor chip is mounted or connected to a circuit substrate in a flip chip bonding manner to shorten interconnection length there between. [0005] In the flip chip bonding manner, a pad formed on the semiconductor chip and an electrode of the circuit substrate are directly bonded together via, for example, a solder ball. This method can provide the shortened interconnections, thereby preventing the occurrence of floating capacitance and inductance and permitting high-speed processing. [0006] However, due to the direct bonding of the pads of the semiconductor component and the electrodes of the circuit substrate, stresses caused by the difference in thermal expansion between the semiconductor chip and the circuit substrate are concentrated in the bonding area of the chip and board to damage those areas. It has been proposed in the Japanese Patent Laid-Open No. 2002-151550 such a device that is shown in FIG. 1. In this device, each pad 102 of a semiconductor chip 101 and each electrode 105 of a circuit substrate 104 are bonded via an electrically conductive coil spring 107 by the both ends of the spring 107 are solder-connected respectively to a solder bump 103 of the chip 101 and a solder electrode 106 of the substrate 104 . With this construction, the coil spring 107 can absorb the differences in thermal expansion between the chip 101 and the circuit substrate 104 . [0007] The present inventor, however, recognized that each of the solders 103 and 106 is sucked into the interior of the coil spring due to the capillary phenomenon, resulting to decrease in bonding strength between the coil spring 107 and the chip 101 and/or between the coil spring 107 and the substrate 104 . The inventor has made it clear that this decrease in strength is due to the fact that the substantive amount of solder 103 and/or 106 has flown into the coil spring 107 . SUMMARY OF THE INVENTION [0008] According to the present invention, there is provided a semiconductor device in which a pad of a semiconductor chip is solder-bonded to an electrode of a circuit substrate via a coil spring, at least on inner surface of which is covered with a material of low wettability against a solder. [0009] The capillary phenomenon that a solder is sucked into the interior of the coil spring during solder bonding is prevented by the material of low solder. As a result, in the bonding area between the coil spring and the pad or the bonding area between the coil spring and the electrode, the solder remains in an amount necessary for solder bonding. Strong soldering bonding can be obtained by this action. BRIEF DESCRIPTION OF THE DRAWINGS [0010] The above and other objects, advantages and features of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: [0011] [0011]FIG. 1 is a view showing a semiconductor device according to the prior art; [0012] [0012]FIG. 2 is a sectional view of a bonding area of the prior art; [0013] [0013]FIG. 3 is a view of a semiconductor device of the first embodiment of the invention; [0014] [0014]FIG. 4 is an enlarged view of a coil spring 7 of FIG. 3; [0015] [0015]FIG. 5 is a schematic representation of an example of the second embodiment of the invention; [0016] [0016]FIG. 6 is a schematic representation of an example of the second embodiment of the invention; [0017] [0017]FIG. 7 is a schematic representation of an example of the fourth embodiment of the invention; [0018] [0018]FIG. 8 is a schematic representation of an example of the fourth embodiment of the invention; [0019] [0019]FIG. 9 is an explanatory drawing of a method of forming a coil spring of FIG. 8; [0020] [0020]FIG. 10 is an explanatory drawing of a method of forming a coil spring in which a material of high wettability by the solder is formed further on an outer surface in FIG. 8; [0021] FIGS. 11 ( a ) and ( b ) are each an explanatory drawing of a method of manufacturing a semiconductor device of the first embodiment of the invention; and [0022] FIGS. 12 ( c ) and ( d ) are each an explanatory drawing of a method of manufacturing a semiconductor device of the first embodiment of the invention (continued from FIGS. 11 ( a ) and ( b )) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0023] Before describing of the present invention, the prior art will be further explained in detail with reference to FIG. 2 in order to facilitate the understanding of the present invention. FIG. 2 shows an enlargement view of the FIG. 1 device and corresponds to the solder bonding between the coil spring 107 and the pad 102 of the semiconductor chip 101 . As shown in the figure, the solder, which has been originally formed on the pad 102 as a solder bump, is sucked up along an inner side surface of the coil spring 107 as indicated by the reference numeral 1031 . For this reason, the amount of solder which remains in the solder bonding area decrease. As a result, the strength of solder bonding decrease. [0024] The invention will be now described hereinbelow with reference to illustrative embodiments. Those skilled in the art will recognize that many alternative embodiments can be accomplished using the teachings of the present invention and that the invention is not limited to the embodiments illustrated for explanatory purposes. [0025] [0025]FIG. 3 is a side view showing the configuration of a semiconductor device in the first embodiment of the invention and FIG. 4 shows an example of coil spring used in the flip chip bonding of this semiconductor device. This semiconductor device 10 is comprised by a semiconductor chip 1 , a circuit substrate 4 and a coil spring 7 . The semiconductor chip 1 is formed from Si, GaAs, Ge, etc. The circuit substrate is formed from glass epoxy, alumina, ceramics, etc. The coil spring 7 is formed from a material of high electrical conductivity, such as Cu. The coil spring 7 used in this embodiment is fabricated by winding a Cu conductive wire having a thickness of 30 μm and has a length of 500 μm, a diameter of 150 μm and a pitch of 25 μm. The pitch called here refers to. “P” shown in FIG. 4. A plurality of pads 2 are formed on a surface of the semiconductor chip 1 and a plurality of electrodes 5 are formed on a surface of the circuit substrate 4 . In this embodiment, the diameter of the pad 2 and electrode 5 is 150 μm, the same value as the diameter of the coil spring 7 . The pad 2 and electrode 5 are formed from Al (aluminum), Ni (nickel), Cu (copper), etc. [0026] The semiconductor chip 1 and circuit substrate 4 are arranged in such a manner that the surface on which the pads 2 are formed and the surface on which the electrodes 5 are formed are opposed to each other. A solder 3 formed from a Pb—Sn alloy is formed on the surface of the pad 2 and a solder 6 formed from a similar alloy is formed on the surface of the electrode 5 . By use of these solders the pad 2 and an end of the coil spring 7 are bonded together and the electrode 5 corresponding to this pad and the other end of the coil spring 7 are bonded together. As shown in FIG. 4, a material 27 of low solder wettability is formed on the surface of the coil spring 7 so that the solder is not sucked into the interior of the coil spring 7 . As a result, the solder remains on the pad 2 and electrode 5 in an amount necessary for the bonding with the coil spring 7 and strong solder bonding can be obtained. [0027] A semiconductor device of this embodiment can be manufactured by the following procedure. [0028] First, as shown in FIG. 11( a ), a bonding pad 2 is formed on a surface of a semiconductor chip 1 and a solder 3 is formed on this bonding pad 2 . The solder 3 can be formed by the ball mounting method, a printing method using a mask, the plating method, etc. [0029] Next, as shown in FIG. 11( b ), a coil spring 7 with the material 27 of low solder wettability is supplied and arranged in each spring positioning hole 11 of a jig 12 in an upright manner. It is desirable that the jig 12 be formed from a material having a coefficient of thermal expansion close to that of the semiconductor chip 1 and heat resistance. The spring positioning hole 11 is formed by a processing method using a drill, a laser, etc. When the diameter of the spring positioning hole 11 is about 10 μm larger than the diameter of the coil spring 7 , it becomes easy to set the coil spring 7 . An evacuation hole 13 is provided on the back surface of the jig 12 . [0030] Next, as shown in FIG. 12( c ), the jig 12 is inverted with the coil spring 7 kept in the positioning hole 11 by evacuating air from the evacuation hole 13 . Subsequently, the jig 12 is moved in such a manner that each coil spring 7 is positioned above the solder 3 formed on the semiconductor chip 1 . Incidentally, a flux is applied beforehand to the solder 3 or coil spring 7 . Subsequently, with the semiconductor chip 1 and the jig 12 kept as one piece, local heating treatment is performed by a reflow furnace or the pulse heat method. At this time, the solder 3 is melted and one end of each coil spring 7 is bonded to the pad 2 by the solder 3 . Although the melted solder is sucked into the interior of the coil spring of the prior art, the material 27 of low solder wettability of this invention prevents the melted solder 3 from being sucked into the coil spring 7 . Subsequently, by performing the cleaning and removal of the flux, a semiconductor chip in which one end of the coil spring 7 is bonded to the pad 2 by the solder 3 is obtained. [0031] Next, as shown in FIG. 12( d ), a circuit substrate 4 on which electrodes 5 are formed is prepared. The electrode 5 is fabricated from Cu, Ni, Au, etc. The circuit substrate 4 is formed from glass epoxy, alumina, ceramics, etc. A solder 6 is formed on the electrode 5 . Subsequently, the semiconductor chip 1 to which the coil springs 7 are bonded is reversed and the semiconductor chip 1 is mounted on the circuit substrate 4 in such a manner that the coil spring 7 is positioned above the solder 6 formed on the circuit substrate 6 . [0032] Next, the same local heating treatment as described above is performed and the solder 6 is melted, whereby the end of the coil spring 7 is bonded to the electrode 5 by the solder 6 . In this case, the compositions of the solder 3 and the solder 6 are adjusted so that the melting point of the solder 6 becomes lower than the melting point of the solder 3 . As a result of this, the other end of the coil spring 7 can be bonded to the electrode 5 by the solder 6 without affecting the bonded state already completed between coil spring 7 and solder 3 . Other embodiments of this invention can be manufactured in the same manner mentioned above. [0033] In the second embodiment, the shape of the coil spring 7 in the first embodiment is changed. Examples of shape of the coil spring 7 are shown in FIGS. 5 and 6. FIG. 5 shows an example of coil spring in which the pitch between ends 8 a and 8 b is smaller than the pitch between middle parts 8 c and 8 d . As shown in this example, the pitch of smaller one can be set to 0. By adopting this shape, the contact area between the end of the coil spring 7 and the solder increases and stronger solder bonding can be obtained. FIG. 6 shows a coil spring in which the middle part is linear. By adopting this shape, the space in the interior of the coil spring decreases and the amount of solder sucked into the interior of the coil spring can be reduced. As a result, the solder remains on the pad and electrode in an amount necessary for solder bonding and strong solder bonding can be obtained. [0034] In the third embodiment, the material of low solder wettability in the first embodiment is changed. Insulating materials, such as resin and metal oxide, and metals of low wettability, etc. can be used as the material of low wettability 27 in FIG. 4. When resin is used, a resin layer can be formed on the coil spring surface by applying a prescribed resin to the surface of a coil spring formed from a material of good electrical conductivity. When a metal oxide film is used, a metal oxide film can be formed on the coil spring surface by heating a metallic coil spring in an oxygen atmosphere. For example, when the coil spring is formed from Cu, the metal oxide film becomes a copper oxide film. When a metal of low wettability is used, a metal film of low wettability can be formed on the coil spring surface by using electrolysis plating or electroless plating. Cr etc. can be used as a metal material of low wettability. [0035] In the fourth embodiment, the place where a material of low wettability is formed in the first embodiment is changed. A material of low wettability may be formed on the whole surface of the coil spring or may be partly formed as shown in FIGS. 7 and 8. In FIG. 7, the material of low wettability 27 is formed in parts other than ends 30 a . By adopting this configuration, it is possible to ensure wettability at the ends 30 a where the solder must adhere. As a result, stronger solder bonding can be obtained. Furthermore, by forming a material of high wettability at the 30 a where a material of low wettability is not formed, the ends 30 a and the solder are brought into closer contact with each other and stronger solder bonding can be obtained. In FIG. 8, the material of low wettability 27 is formed on an inner side surface 26 a of the coil spring. If the material of low wettability 27 is formed on the inner side surface 26 a of the coil spring, it is possible to reduce the degree of the capillary phenomenon. As a result, the solder remains on the pad 2 and electrode 5 in an amount necessary for solder bonding and it is possible to adequately obtain the effect that solder bonding becomes strong. Also, by preventing the material of low wettability 27 from being formed on an outer side surface 26 b of the coil spring, the outer side surface 26 b of the coil spring and the solder come into close contact with each other and stronger solder bonding can be obtained. [0036] In forming a material of low wettability in part of the coil spring, the following method can be adopted. When resin is used as a material of low wettability, a prescribed resin is applied to a necessary place. When a metal oxide film is used as a material of low wettability, a metallic coil spring is first heated in an oxygen atmosphere and a metal oxide film is formed on the whole surface of the metallic coil spring. By causing the part 30 a of FIG. 7 and the part 26 b of FIG. 8 in the metal oxide film to fly by laser irradiation thereby to remove them, it is possible to form a metal oxide film in parts other than the end and outer side surface of the coil spring as shown in FIGS. 7 and 8. When the metal material of low wettability 27 is formed on the inner side surface 26 a of the coil spring as shown in FIG. 8, the following method can be adopted. First, as shown in FIG. 9, a metal of low wettability 271 is formed by the plating method etc. only on one side of a conductive wire 28 . By winding this conductive wire 28 in such a manner that the metal of low wettability 271 is provided on the inner side surface of the coil spring, it is possible to obtain the coil spring in which the metal of low wettability 271 is formed on the inner side surface. [0037] Stronger solder bonding can be obtained when a material of high solder wettability is formed on the outer side surface in addition to the formation of the metal of low wettability on the inner side surface of the coil spring. This is due to the following principle. Because the material of low wettability is formed on the inner side surface in the interior of the coil spring, the suction of the solder into the interior of the coil spring is suppressed. On the other hand, because the material of high wettability is formed on the outer side surface of the coil spring, the solder spreads up along the outer side surface of the coil spring. At this time, the sucking up of the solder into the interior of the coil spring is more suppressed because a large amount of solder gathers on the outer side surface. At the same time, a larger amount of solder comes into contact with the outer side surface of the coil spring. Owing to the combined effects of the two phenomena, strong solder bonding can be obtained. For example, Au can be used as the material of high wettability. [0038] A coil spring in which a material of low wettatbility is formed on the inner side surface and a material of high wettatbility is formed on the outer side surface can be made by the following method. First, as shown in FIG. 10, a material of low wettability 27 such as Cr is formed on one half surface of the conductive wire 28 and a material of high wettability 29 such as Au is formed on the other half surface. Next, this conductive wire 28 is wound in such a manner that the material of low wettability 27 is provided on the inner side surface to form a coil spring. [0039] It is apparent that the present invention is not limited to the above embodiments, but may be modified and changed without departing from the scopes and spirits of the invention.

Disclosed herein is a semiconductor device in which a semiconductor chip is bonded at its pad to an electrode of a circuit substrate via a coil spring by solder-connecting both ends of the spring respectively to the pad and the electrode. There is provided a material having low solder wettability that covers at least part of the surface of the coil spring, so that the solder is prevented from being sucked into the Interior of the coil spring. A semiconductor device of the present invention comprises a semiconductor chip, a circuit substrate and a coil spring electrically connecting the semiconductor chip and the circuit substrate by a solder. In order to prevent the solder from being sucked into the interior of the coil spring, a material having low wettability by the solder is formed on the surface of the coil spring.

CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of application Ser. No. 08/241,035, filed May 10, 1994, and issuing as U.S. Pat. No. 5,480,409 on Jan. 2, 1996. BACKGROUND OF THE INVENTION This invention relates in general to surgical instruments and in particular to an improved structure for a laparoscopic surgical instrument. Laparoscopic surgery is a relatively new operating technique which is much less invasive than conventional surgery and, therefore, may be performed using only a local anesthetic. Such laparoscopic surgery involves puncturing a relatively small opening through the abdominal wall and introducing an inert gas within the abdomen. The introduction of the inert gas expands the abdomen to facilitate access to the body parts requiring surgery and visual observation of the procedure. A hollow cylindrical tube is inserted into the puncture and is subsequently used as a conduit through which one or more elongated surgical instruments may be inserted within the abdomen. If desired, a plurality of such relatively small punctures may be formed through the abdominal wall to facilitate the use of several surgical instruments. A number of laparoscopic surgical instruments are known in the art for use in laparoscopic surgical procedures. Although they vary widely in structure and operation, such laparoscopic surgical instruments generally include three basic components. First, a typical laparoscopic surgical instrument includes a handle which is grasped and manipulated by the user. The handle may be designed in the general hand of the user. Alternatively, the handle may be designed in the general shape of a hypodermic needle grip for engagement only by the thumb and fingers of the user. In either event, the handle usually includes one or more movable components which can be manipulated by the user for a purpose described below. Second, a typical laparoscopic surgical instrument includes an elongated shaft portion which extends from the handle. The elongated shaft portion is provided for extending through the hollow cylindrical tube discussed above during the laparoscopic surgical operation. The elongated shaft portion may include an actuator member which is connected for movement or other operation with the movable component of the handle. Third, a typical laparoscopic surgical instrument includes a tool portion mounted on the end of the elongated shaft portion. The tool portion is connected to the actuator member of the elongated shaft portion such that movement of the movable component of the handle causes operation of the tool portion. As mentioned above, a number of laparoscopic surgical instruments of this general type are known in the art. In some of such known laparoscopic surgical instruments, the associated tool portions may be rotated relative to the handle to a desired orientation by manually rotating a thumbwheel fixed to the associated shaft portions. It would be desirable to provide an improved structure for a laparoscopic surgical instrument of this general type that can be motorized to facilitate the use thereof. Additionally, in other ones of such known laparoscopic surgical instruments, the elongated shaft portions and associated tool portions are permanently secured to the handle. Thus, the entire laparoscopic surgical instrument must be sterilized or disposed of after use. It would also be desirable to provide an improved structure for a laparoscopic surgical instrument of this general type in which the elongated shaft portion and associated tool portion are removable from the handle. This will allow the relatively inexpensive elongated shaft portion and associated tool portion to be disposed of after use, while allowing the relatively expensive handle to be sterilized and reused. SUMMARY OF THE INVENTION This invention relates to a surgical instrument including a handle adapted to releasably engage a shaft portion mounting a tool having relatively moveable parts. The handle is provided with an actuating structure which includes a trigger arm selectively moveable relative to the handle to cause concurrent movement of the relatively moveable parts of the tool. The actuating structure may include a locking mechanism for releasably fixing the position of the handle relative to the handle, thus releasably fixing the relative positions of the moveable parts of the tool. The handle is also provided with an operating mechanism which is operatively coupled to the tool to selectively rotate the tool relative to the handle. The operating mechanism may be motorized. The operating mechanism may include a control circuit which can be programmed to activate the motor to rotate the tool through specific intervals of displacement is a chosen direction according to selective manipulations of control switches. Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a laparoscopic surgical instrument in accordance with this invention showing a first side thereof FIG. 2 is another perspective view of the instrument illustrated in FIG. 1, showing a second side thereof. FIG. 3 is an enlarged fragmentary elevational view, partly in section, of the instrument illustrated in FIGS. 1 and 2, with one side piece of the handle removed to reveal the interior components thereof. FIG. 4 is an enlarged elevational view, partly in section, taken along the line 4--4 of FIG. 3. FIG. 5 is an enlarged elevational view, partly in section, taken along the line 5--5 of FIG. 3. FIG. 6 is an enlarged view of the contact shown in FIG. 3. FIG. 7 is an enlarged elevational view, partly in section, taken along the line 7--7 of FIG. 3. FIG. 8 is a fragmentary elevational view, partly in section, of a second embodiment of a laparoscopic surgical instrument in accordance with this invention. FIG. 9 is an enlarged elevational view, partly in section, of the receiver portion shown in FIG. 8. FIG. 10 is an enlarged elevational view, partly in section, of the tool of the instrument shown in FIG. 8. FIG. 11 is an elevational view, partly in section, of a third embodiment of a laparoscopic surgical instrument in accordance with this invention, and having an adjustably mounted grip portion. FIG. 12 is a proximal end view, partly in section, of the instrument shown in FIG. 11. FIG. 13 is a view similar to FIG. 11 showing a fourth embodiment of the instrument of this invention, showing a different structure for adjustably mounting the grip portion of the handle portion. FIG. 14 is a proximal end view, partly in section, of the instrument shown in FIG. 13. FIG. 15 is fragmentary view, partly in section, showing a fifth embodiment of the instrument of this invention, showing a different structure for adjustably mounting the grip portion of the handle portion. FIG. 16 is a view similar to FIG. 15, showing the cam of the locking mechanism thereof in a lock position. FIG. 17 is a proximal end view, partly in section, of the instrument shown in FIGS. 15 and 16. FIG. 18 is a view similar to FIG. 11 showing a sixth embodiment of the instrument of this invention, showing a different structure for adjustably mounting the grip portion of the handle portion. FIG. 19 is a proximal end view of the instrument shown in FIG. 18. FIG. 20 is a view similar to FIG. 15 showing a seventh embodiment of the instrument of this invention, showing a different structure for adjustably mounting the grip portion of the handle portion. FIG. 21 is a view taken along the line 21--21 of FIG. 20, illustrating the locking mechanism thereof in an unlock condition. FIG. 22 is a view similar to FIG. 21, illustrating the locking mechanism thereof in an lock condition. FIG. 23 is a side elevation view of an eighth embodiment of the instrument of this invention, showing a different structure for adjustably mounting the grip portion of the handle portion. FIG. 24 is a view similar to that of FIG. 23, partly broken away to illustrate the locking mechanism thereof. FIG. 25 is an enlarged view of the locking mechanism illustrated in FIG. 24. FIG. 26 is a view taken along the line 26--26 of FIG. 25, showing the locking mechanism in a lock position. FIG. 27 is a view similar to that of FIG. 26, showing the locking mechanism thereof in an intermediate position. FIG. 28 is a view similar to that of FIG. 26, showing the locking mechanism thereof in an unlock position. FIG. 29 is a side elevation view of a ninth embodiment of the instrument of this invention, showing a different structure for adjustably mounting the grip portion of the handle portion. FIG. 30 is a proximal end view of the instrument shown in FIG. 29. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, there is illustrated in FIGS. 1 through 3 a first embodiment of a laparoscopic surgical instrument, indicated generally at 10, in accordance with this invention. The instrument 10 includes a pistol-shaped handle 11, a shaft portion 12 which is releasably secured by the proximal end thereof to the handle 11, and a tool 13 secured to the distal end of the shaft portion 12, each of which will be described in greater detail below. As used in this application, "proximal" means that portion of the structure under discussion which is normally close to the user when the instrument 10 is in use. Similarly, "distal" refers to that portion of the structure under discussion which is farther away from the user holding the instrument 10. The handle 11 includes a hollow pistol grip portion 14 on top of which integrally extends a hollow receiver portion 15. Preferably, the pistol-shaped handle 11 is made of two symmetrical side pieces 16 and 17, preferably molded of a plastic material, that are detachably connected by conventional means, such as screws 18. Each of the side pieces 16 and 17 define half of the grip portion 14 and half of the receiver portion 15. The side pieces 16 and 17 of the handle 11 are preferably formed of a material which can be repeatedly sterilized in a conventional manner without degrading the performance of the instrument 10. It is anticipated that the handle 11 of the instrument 10 will frequently be grasped by the grip portion 14 such that the grip portion 14 extends generally downwardly toward the floor and the receiver portion 15 is disposed generally upwardly of the grip portion 14 and extends generally horizontally. Therefore, the terms "up", "down", "upper", and "lower", and terms of similar import used to describe the layout of the instrument 10 will be understood to refer to the instrument 10 while held in that orientation, although the instrument 10 may certainly be operated in other orientations. As shown in FIG. 3, the handle 11 is sized and shaped to contain an operating mechanism 19 for actuating and rotating the tool 13. In the preferred embodiment, the portion of the operating mechanism 19 which rotates the tool 13 is powered by batteries 20 disposed within the grip portion 14. Lithium batteries are preferred for their relatively long shelf life and flat discharge characteristics. It has been estimated that two DL123A (3 volt, 1310 milliamp-hour) lithium batteries will operate the instrument 10 long enough to perform approximately one thousand typical surgical procedures, or approximately two years in normal use. Of course, other battery arrangements may be used. For example, a rechargeable battery may be utilized, and provided with an electrical plug molded through the grip portion 14 to permit recharging of the battery between uses of the instrument 10. Alternatively, the grip portion 14 may be provided with a window to permit easy access to relatively frequently replaced disposable batteries contained within the grip portion 14. Each of the side pieces 16 and 17 is provided with a rib 21 (only the rib 21 on the side piece 17 is shown, in FIG. 3) extending transversely across the grip portion 14. The ribs 21 of the side pieces 16 and 17 mate to form a bulkhead separating the batteries 20 from the rest of the operating mechanism 19. An electrical connector 22 is supported by the ribs 21. The connector 22 is electrically connected to and supports one end of the batteries 21. A second, similar connector (not shown) is supported by a similar set of ribs (also not shown) traversing a lower part 23 (FIGS. 1 and 2) of the grip portion 14. This second connector is electrically connected to and supports the other end of the batteries 20. An electrical conductor 24, electrically connected to the second connector, passes through the bulkhead formed by the ribs 21. The penetrations of the conductor 24 and the connector 22 through the bulkhead formed by the ribs 21 as well as the joint between the two opposed ribs 21 are substantially leak-tight, to protect the rest of the operating mechanism 19 in the event of leakage from the batteries 20. The battery powered portion of the operating mechanism 19 is preferably regulated by a control circuit 25. The conductor 24 and the connector 22 are electrically connected to the control circuit 25, thereby connecting the batteries 20 as a power source to the control circuit 25. The control circuit 25 includes conventional low battery voltage detection circuitry (not shown) which controls the operation of a low battery indicating light 26 (FIG. 2) mounted on the side piece 16. Of course, although only a single low battery indicating light 26 is shown, a second low battery indicating 26 may be provided in the side piece 17, or the location of the low battery indicating light 26 moved to any desired location to provide ambidextrous indication of a discharged battery condition. Commands to direct rotation of the tool 13 are input to the control circuit 25 by means of a pair of identical thumb switches 27 and 28 (FIGS. 1 and 2). The thumb switch 27 is mounted on the side piece 16 where it may be conveniently operated by the user's right thumb as the instrument 10 is held in the user's right hand (FIG. 2). Similarly, the thumb switch 28 is mounted on the side piece 17 where it may be conveniently operated by the user's left thumb as the instrument 10 is held in the user's left hand (FIG. 1), providing for ambidextrous operation of the instrument 10. The thumb switches 27 and 28 are preferably of the conventional rocker switch type, in which single member, centrally pivoted, may have either end depressed to actuate a respective microswitch under the selected end. A microswitch which is believed to be suitable is available from C&K Switch of Newton, Mass. By actuating one of the microswitches of the thumb switch 27, the user can direct clockwise rotation of the tool 13; by actuating the other of the microswitches of the thumb switch 27, the user can direct counter-clockwise rotation of the tool 13. Similarly, the thumb switch 28 can be used to direct clockwise or counter-clockwise rotation of the tool 13. The control circuit 25 preferably includes a programmable microprocessor to precisely regulate the operation of the operating mechanism 19 in response to engagement of the thumb switches 27 and 28. For example, the microprocessor may be programmed to cause the operating mechanism 19 to rotate the tool 13 continuously in the clockwise direction while a first one of the microswitches of the thumb switch 27 is actuated, stopping the tool 13 when the thumb switch 27 is released. The microprocessor can be programmed to rotate the tool 13 continuously in the counter-clockwise direction while the other one of the microswitches of the thumb switch 27 is depressed, stopping if the thumb switch 27 is released or after the tool 13 has rotated a first predetermined amount (such as 360°). Preferably the microprocessor in the control circuit 25 will be programmed to respond to the thumb switch 28 in a manner similar to that programmed for the thumb switch 27. In one suitable ergonomic arrangement, the thumb switches 27 and 28 will be connected to the control circuit 25 such that actuation of the upper microswitch of the thumb switch 27 or the lower microswitch of the thumb switch 28 will result in clockwise rotation of the tool 13. Similarly, actuation of the upper microswitch of the thumb switch 28 or the lower microswitch of the thumb switch 27 will, result in counter-clockwise rotation of the tool 13. Of course, those of ordinary skill in the art will recognize that the microprocessor of the control circuit 25 may be programmed to control the rotation of the tool 13 in a variety of ways in response to actuation and release of the thumb switches 27 and 28. For an additional example, it is contemplated that the control circuit 25 can be caused to keep track of the number of times a thumb switch 27 or 28 is actuated within a predetermined period of time, and vary control of the tool 13 in response thereto. The output of the control circuit 25 is directed to a conventional motor assembly 29. The motor assembly 29 includes an encoder 30, a motor 31 and a set of reduction gears 32. A motor assembly which is believed to be suitable is available as Model No. 1219E006GK380 from Micro Mo Electronics, Inc., of St. Petersburg, Fla. An output member 33 is pressed onto, or otherwise suitably secured to the output shaft of the reduction gears 32 of the motor assembly 29. In the preferred embodiment, the output member 33 has a generally oval cross-section. The purpose of the output member 33 will be explained below. The motor assembly 29 is supported within a tubular support 35. An axial bore 36 is defined through the support 35. A proximal portion 37 of the bore 36 defines a relatively large diameter. A distal portion 38 of the bore 36 defines a relatively small diameter. An intermediate portion 39 is defined between the proximal portion 37 and the distal portion 38, and defines a diameter which is smaller than that of the proximal portion 37 but larger than that of the distal portion 38. Thus, a first shoulder 40 is defined between the proximal portion 37 and the intermediate portion 39 of the bore 36. A second shoulder 41 is defined between the intermediate portion 39 and the distal portion 38 of the bore 36. The distal end of the motor assembly 29 is mounted within the proximal portion 37 of the bore 36 with the distal end of the motor assembly 29 abutting the first shoulder 40 within the bore 36 to axially position the motor assembly 29. A pair of opposed set screws 42, which are threaded into the support 35, engage the motor assembly 29 to retain the motor assembly 29 in the support 35 and to prevent the motor assembly 29 from rotating relative thereto. The support 35 has an outwardly extending flange 43 at the distal end thereof. The flange 43, which has a rectangular cross-section, engages a mating recess 44 extending about the inner surface of the hollow receiver portion 15 of the handle 11, so that the support 35 is axially positioned and supported within the handle 11 (FIGS. 3 and 4). The receiver portion 15 of the handle 11 has a generally rectangular cross-section and thus engages the rectangular flange 43 to prevent rotation of the support 35 relative to the handle 11. Preferably the recess 44 provides a close fit with the flange 43, such that a moisture resistant seal is formed therebetween. A generally cylindrical coupling 45 is provided to transmit torque from the output member 33 on the output shaft of the motor assembly 29 to the shaft portion 12 of the instrument 10. The coupling 45 includes a body 46 which is preferably molded of a plastic material which transmits torque well and, for reasons which will be discussed below, has good electrical insulation properties. The body 46 has a first axially extending recess 47 formed on the proximal end thereof, and has a second axially extending recess 48 formed on the distal end thereof. A radially outwardly extending flange 49 is formed on the proximal end of the body 45. A circumferential groove 50 is formed in the outer surface of the body 46, intermediate the flange 49 and the distal end of the body 46. A hollow metallic insert 51 is preferably secured in the first recess 47. The insert 51 may be secured therein using any conventional means such as an adhesive, or molding the body 45 about the insert 51. The insert 51 has a cavity 52 adapted to receive the output member 33 of the motor assembly 29 to couple the output member 33 of the motor assembly 29 for rotation of the coupling 45. The flange 49 is rotatable within the intermediate portion 39 of the bore 36 through the support 35. The flange 43 defines a diameter which is greater than the diameter of the distal portion 38 of the bore 36. Thus, the coupling 46 is prevented from moving away from the motor assembly 29 beyond a first axial position relative to the motor assembly by the second shoulder 41 of the support 35. The coupling 45 is prevented from moving toward the motor assembly 29 beyond a second axial position defined where the output member 33 bears against the bottom of the cavity 52 in the insert 51 in the proximal end of the coupling 45. The fit of the output member 33 within the cavity 52 in the insert 51 is such that the coupling 45 can move axially between the first and second axial positions relative to the motor assembly 29. The coupling 45 can thus rotate freely with the flange 49 thereof free to move axially to a position spaced slightly apart from the second shoulder 42 of the support 35. An elastomeric O-ring 53 disposed in the groove 50 and bears against the distal portion of the bore 36 through the support 35, thereby providing a moisture resistant seal between the coupling 45 and the support 35. It will be appreciated that the O-ring, cooperating with the coupling 45 and the support 35 prevent passage of moisture from the distal end of the handle 11 to the proximal end thereof. Recalling the bulkhead formed by the cooperating ribs 21 formed on the side pieces 16 and 17, it will be further appreciated that the motor assembly 29 and the control circuit 25 are thus contained in a moisture-proof compartment. Thus, these electrical components are protected from the various fluids to which the instrument 10 may be exposed, such as during surgery and during sterilization. Additionally, the motor assembly 29 and control circuit 25 may be shielded against induced voltages from other electrical equipment or components which may be in use nearby. For example, the compartment in which the motor assembly 29 and control circuit 25 are contained may be lined with a conductive foil 54 (shown diagrammatically by a broken line in FIG. 3) to shield these components. A metallic insert 55 is fixed in the recess 48 formed on the distal end of the coupling 45. As with the insert 51 in the recess 47, the insert 55 may be fixed in the recess 48 by conventional means. As seen in FIG. 4, the insert 55 is hollow and provided with inwardly extending splines 56, the purpose of which will be explained below. Referring again to FIG. 3, the shaft portion 12 of the instrument 10 an inner rod or actuating member 60 which is moveable within an outer tube 61. A circumferential groove 62 is formed intermediate the proximal and distal ends of the actuating member 60, preferably near the proximal end thereof. The proximal end of the actuating member 60 is formed as an axially extending flat tongue 63. The tongue 63 extends within the insert 55 of the coupling 45, and engages the splines 56 therein. Thus, rotation of the coupling 45 by the motor assembly 29 causes the actuating member 60 of the shaft portion 12 of the instrument 10 to rotate. In the embodiment illustrated in FIGS. 1 and 2, the distal end of the actuating member 60 (not shown) is fixed to the tool 13 in a conventional manner. Thus, rotation of the actuating member 60 causes the tool 13 to rotate. The operating mechanism 19 further includes an actuating structure 65 for moving the actuating member 60 axially relative to the tube 61, in order to actuate the tool 13. The actuating structure 65 can move the actuating member 60 only a relatively short distance. Such movement of the actuating member 60 relative to the coupling 45 is accommodated by movement of the tongue 63 forming the proximal end of the actuating member 60 relative to the splines 56 within the insert 55 in the coupling 45. The actuating structure 65 includes a trigger arm 66. The trigger arm 66 which is preferably made from a plastic material, may be formed as a single piece, or, as is shown in FIGS. 1 and 2, formed from two mating portions 67 and 68 secured together by suitable conventional means, such as screws 69. In either case, the lower portion of the trigger arm 66 is provided with a finger grip 70 for actuating the trigger arm 66. The finger grip 70 is preferably formed as an elongate opening through the trigger arm to aid the user (not shown) in grasping the instrument 10. The upper portion of the trigger arm 66 is formed as a yoke, having a pair of yoke arms 71 and 72 extend on either side of the receiver portion 15 of the handle 11 (as best seen by referring to FIGS. 1, 2, and 5). An aperture 71a is formed through the yoke arm 71. Similarly, an aperture 72a is formed through the yoke arm 72. The purpose of the apertures 71a and 72a will be explained below. A pin 73 extends between the yoke arms 71 and 72, and through the receiver portion 15 of the handle 11, to pivotally mount the trigger arm 66 on the handle 11 for movement relative thereto. A bore 74 extends vertically through the upper portion of the trigger arm 66, extending from between the yoke arms 71 and 72 to a central recess 75 formed in the distal face of the trigger arm 66. A second central recess 76 is formed on the proximal face of the trigger arm 66. The purpose of the bore 74 and of the recesses 75 and 76 will be explained below. A spring 77 or similar resilient structure is provided for urging the trigger arm 66 to a first position, relatively away from the grip portion 14 of the handle 11. The first position of the trigger arm 66 corresponds to the unactuated condition of the tool 13. As will be further explained below, when the trigger arm 66 is moved toward the handle 11 to a second position, the tool 13 is actuated. A pin extends between the side pieces 16 and 17, and through a loop in the spring 77 to retain the spring 77 in place relative to the handle 11. One arm 77a of the spring 77 is retained in the recess 76 formed in the proximal face of the trigger arm 66, and bears against the trigger arm 66. The other arm 77b of the spring 77 bears against the grip portion 14 of the handle 11. The trigger arm 66 is provided with a releasable locking mechanism 78 for selectively retaining the trigger arm 66 (and thus the moveable portions of the tool 13) at substantially any selected position within the range of movement thereof. Preferably, the locking mechanism 78 is embodied as a surface feature forming a ratchet 79 and a pawl 80 which can easily engage and disengage the ratchet 79 to lock and unlock the instrument 10 as desired. The ratchet 79 is preferably formed as a series of laterally extending teeth 81 formed in a convex arc on the underside of the receiver portion 15 of the handle 11. However, it will be understood that other surface features, such as slots formed in the handle 11 may be suitably used. The pawl 80 is reciprocal in the bore 74 of the trigger arm 66 to selectively engage and disengage the ratchet 79. Preferably the upper surface of the pawl 80 is provided with a plurality of laterally extending teeth 82 arranged on a concave arc. This arcuate arrangement of the teeth 81 and 82 permits multiple teeth 82 of the pawl 80 to engage the teeth 81 of the ratchet 79 at any point in the travel of the trigger arm 66. Thus, multiple ones of the teeth 81 and 82 can share any loads which may be experienced. The pawl 80 is pivotally connected to a toggle arm 83 which in turn is pivotally connected to a bell crank lever 84. The lever 84 has arms 84a and 84b formed at an angle to one another. The lever 84 is pivotally mounted within the recess 75 on the distal face of the trigger arm 66. The arm 84a of the lever 84 and the toggle arm 83 form a toggle joint such that if the user presses the arm 84a or the toggle arm 83 inwardly into the recess 75, the pawl 80 will be moved upwardly into engagement with the ratchet 79. The user presses the arm 84b inwardly into the recess 75 to cause the lever 84 to pivot the arm 84a outwardly. This in turn causes the toggle arm 83 to pull the pawl 80 out of engagement with the ratchet 79. Thus the user can selectively lock or unlock the trigger arm 66 in the first position thereof, the second position thereof, or at any intermediate position by pressing a finger against, respectively, the arm 84a or the arm 84b of the lever 84. As most clearly shown in FIG. 5, a trunnion 85 extends between the yoke arms 71 and 72 of the trigger arm 66 and through openings 86 and 87 in, respectively, the side pieces 16 and 17 of the handle 11. As shown by the broken line in FIG. 3, the opening 87 in the side piece 17 is an elongated oval with sufficient clearance to accommodate the movement of the trunnion 85 as the trigger arm 66 is moved between the first and second positions thereof. The opening 86 in the side piece 16 has a similar shape. The trunnion 85 includes a generally cubical receiver portion 88. The receiver portion 88 has a pair of relatively smaller cylindrical extensions 89 extending out of opposed faces. The extensions 89 extend through the openings 86 and 87 in the side pieces 16 and 17 to engage respective ones of the apertures 71a and 72a in the yoke arms 71 and 72 of the trigger arm 66. The lateral faces of the receiver portion 88 bear against the side pieces 16 and 17 to secure the trunnion 85 laterally relative to the receiver portion 15 of the handle 11. The trunnion 85 is provided with a first bore 90 extending from a first end 91 of the trunnion to a point adjacent a second end 92 of the trunnion. Thus the first bore 90 forms a recess in the first end 91 which extends more than half way, but not all the way, through the trunnion 85. Additionally, a second bore 93 extends horizontally through the middle of the trunnion 85 perpendicular to, and communicating with, the first bore 90. The actuating member 60 of the shaft portion 12 extends through the second bore 93. A detent 94 is mounted for reciprocation in the first bore 90 in the trunnion 85. The detent 94 is generally cylindrical, and includes a first generally cylindrical bearing portion 95, a receiver portion 96 formed as a flat plate, a second cylindrical bearing portion 97, and a reduced diameter cylindrical guide portion 98. The bearing portions 95 and 97 slidingly engage the surface of the first bore 90 of the trunnion 85 to radially position the detent 94. A pear-shaped opening 99 is formed through the receiver portion 96 of the detent 94. The actuating member 60 extends through the pear-shaped opening 99. The pear-shaped opening 99 is oriented such that the larger diameter portion 100 thereof is closer to the first bearing portion 95 of the detent 94, and the smaller diameter portion 101 is closer to the second bearing portion 97 of the detent 94. The smaller diameter portion 101 of the pear-shaped opening 99 has a vertical diameter which is slightly greater than the diameter of the actuating member 60 at the base of the groove 62 therein, and less than the diameter of the actuating member 60 adjacent to the groove 62. The larger diameter portion 100 of the pear-shaped opening 99 has a vertical diameter which is slightly greater than the diameter of the actuating member 60 adjacent to the groove 62. Thus, when the detent 94 is positioned such that the actuating member 60 passes through the larger diameter portion 100 of the pear-shaped opening 99, the actuating member 60 may be moved axially relative to the detent 94. Thus the detent 94 is in a disengaged position. However, when the groove 62 in the actuating member 60 is aligned with the receiver portion 96 of the detent 94, the detent 94 may be moved laterally relative to the actuating member 60, such that the receiver portion 96 of the detent 94 engages the groove 62. When the actuating member 60 is thus engaged by the detent 94, the axial position of the actuating member 60 is fixed relative to the detent 94 within the trunnion 85. Thus, when the trunnion 85 is moved by the trigger arm 66 of the actuating structure 65, the actuating member 60 will move axially with the detent 94 within the trunnion 85. The detent 94 is thus in the engaged position. It will be noted that the apertures 71a and 72a in respective yoke arms 71 and 72, are moved through an arc by the trigger arm 66, while the actuating member 60 to which the trunnion 85 is fixed reciprocates linearly. However, the arc of movement of the apertures 71a and 72a is relatively short, so that little change in vertical position occurs. What little vertical displacement of the trunnion 85 which would otherwise occur is accommodated by sizing the apertures 71a and 72a to receive the trunnion 85 with a relatively loose fit. A vertical bore 102 is formed through the first bearing portion 95 of the detent 94. A pin 103 extends through the bore 102, and is fixed at either end thereof in the cylindrical extension 89 at the first end 91 of the trunnion 85. The bore 102 is laterally elongated, thus permitting the detent 94 to be reciprocated within the first bore 90 of the trunnion 85. However, the pin 103 through the bore 102 prevents the detent 94 from being removed or ejected from the trunnion 85. A spring 104 or similar resilient structure is provided for urging the detent 94 toward the engaging position toward the first end 91 of the trunnion 85. The spring 104 is preferably formed as a coil disposed about the guide portion 98 of the detent 92, bearing against the second bearing portion 97 of the detent 92 and the closed end of the first bore 90. When the detent 94 is positioned in the engaging position, the end of the first bearing portion 95 extends outwardly beyond the yoke arm 72 of the trigger arm 66. As will be further explained below, the user may push the face of the protruding first bearing portion 95 to move the detent 94 toward the disengaged position, compressing the spring 104. When the detent 94 is released, the spring 104 urges the detent 94 to move toward the engaged position thereof. If desired, means for electrically energizing the actuating member 60 may be provided in order to use the instrument 10 for cauterization. Although the concept of using a laparoscopic surgical instrument for cauterization is conventional, the instrument 10 has a unique contact assembly 105 for energizing the actuating member 60 while permitting axial and rotary relative movement therebetween. As best seen in FIG. 6, the contact assembly 105 includes a socket 106 having a central bore 107 through which the actuating member 60 extends. The socket 106 is formed of a conductive solid material, preferably a copper alloy. A circumferential groove 108 is formed on the inner surface of the socket 106, within the bore 107. A conventional canted coil spring 109 is retained in the groove 108, and provides a sliding conductive contact with the actuating member 60. The spring 109 may be formed from a beryllium-copper alloy and then silver plated. A suitable canted coil spring may be obtained from Bal Seal Engineering Company, Inc. of Santa Ana, Calif. In the canted coil spring 109, the coils are canted to one side about the circumference of the looped coil. This arrangement permits the actuating member 60 to be inserted through the bore 107 of the disk 105 with reduced effort to expand the spring 109, when compared to the effort required to insert the actuating member 60 past a coil spring in which the coils are not canted. The socket 106 is provided with a set screw 110 which secures an electrical conductor 111 to the socket 106. As seen in FIG. 3, the conductor 111 is electrically connected to a plug 112 mounted to extend through the handle 11 of the instrument 10. Thus, electrical power for cauterization is supplied to the tool 13 through the plug 112, the conductor 110, the socket 106, the spring 104, and the actuating member 60. The patient is electrically grounded in a conventional manner to complete the electrical circuit required for cauterization. The contact assembly 105 further includes a tubular socket housing 113 for supporting the socket 106. The socket housing 113 is fixed at the proximal end thereof to the distal face of the receiver portion 88 of the trunnion 85. The socket housing 113 holds the socket 106 with the bore 107 in the socket 106 in axial alignment with the second bore 93 through the trunnion 85. The socket 106 is captured in the socket housing 113 by a socket housing cap 114 fixed to the distal end of the socket housing 113. The socket housing cap 114 is disk-shaped and is formed with a central opening 115, through which the actuating member 60 extends into the socket 106. Preferably the distal end of the central opening 115 is chamfered or otherwise enlarged to ease the alignment and insertion of the actuating member 60 through the socket housing cap 114. The socket housing 113 and the socket housing cap 114 are slidingly supported for reciprocation with the trunnion 85 within a tubular part of the receiver portion 15 of the handle 11. It should be noted that sufficient clearance must be provided between non-axially moveable components and the reciprocating trunnion 85 and contact assembly 105 to accommodate relative movement therebetween caused by movement of the trigger arm 66 between the actuated position and unactuated position. The distal end of the receiver portion 15 of the handle 11 is formed into an opening 116, through which the actuating member 60 extends. A circumferential groove 117 is formed on the inner surface of the distal end of the receiver portion 115, spaced inwardly of the opening 116. The purpose of the groove 117 will be explained below. Referring now to FIGS. 3 and 7, an adapter assembly 118 is provided for releasably securing the tube 61 of the shaft portion 12 to the handle 11. The adapter assembly 118 includes an adapter body 119. The adapter body 119 is formed with a central opening 120 to accommodate insertion of the shaft portion 12. The adapter body 119 is preferably formed with an annular extension 121 on the proximal end thereof. The extension 121 extends into the receiver portion 15 of the handle 11 through the opening 116. The extension 121 is formed with a radially outwardly extending flange 122 which engages the circumferential groove 117 in the receiver portion 15 of the handle 11 to retain the adapter body 119 on the distal end of the handle 11. Preferably the flange 122 fits tightly within the groove 117 so that adapter body 119 does not rotate freely relative to the handle 11, but rather will remain in a position to which the adapter body 119 is rotated by the user. The periphery of the adapter body 119 is preferably scalloped, as seen in FIG. 7, to enable the user to easily grasp and turn the adapter body 119. The adapter body 119 is formed with a slot 123 extending linearly across the distal face thereof. Inwardly extending flanges 124 and 125 are formed on either side of the slot 123. An longitudinally extending groove 126 is formed in the radially outer surface of the adapter body 119 from the base of the slot 123 to the proximal face of the adapter body 119. A radially inwardly extending recess 127 is formed in the adapter body 119 spaced slightly apart longitudinally from the distal end of the groove 126. The purpose of the slot 123, the groove 126 and the recess 127 will be explained below. The adapter body is preferably molded of a suitable plastic material. The adapter assembly 118 also includes an adapter detent 128. The adapter detent 128 is preferably a metallic part cast as a flat strip having a proximally-extending flange 129 formed at one end thereof. A generally pear-shaped opening 130 is formed through the adapter detent 128. The opening 130 has a wide portion 131, a receiver portion 132, and an elongated narrow portion 133. Preferably, the receiver portion 132 is beveled outwardly on the distal side thereof, for a purpose which will be discussed below. The adapter detent 128 is reciprocally mounted in the slot 123. The flanges 124 and 125 extend over the adapter detent 128 to retain the adapter detent 128 in the slot 123. The flange 129 is disposed in the groove 126, and extends over the recess 127. A spring 134 is seated in the recess 127, and acts to urge the flange 129, and thus the adapter detent 128, radially outwardly. The detent is prevented from moving radially outwardly out of the slot 123 by a screw 135. The screw 135 extends through the narrow portion 133 of the opening 130 and is threaded into the adapter body 119. When a user presses the flange 129 radially inwardly, compressing the spring 134, the wide portion 131 of the opening 130 in the adapter detent 128 is moved into alignment with the opening 115 in the socket housing cap 114. When the flange 129 is released, the spring 134 moves the adapter detent 128 radially outwardly until the adapter detent 128 is stopped by the screw 135. In this position, the receiver portion 132 of the opening 130 is in alignment with the opening 115 in the socket housing cap 114. The shaft portion 12 has an adapter bushing 136 fixed about the proximal end of the tube 61. As best seen in FIG. 3, the bushing 136 generally increases in thickness toward the distal end thereof. A circumferential groove 137 is defined in the bushing 136 spaced from the distal end thereof. When the shaft 12 is installed in the handle 11, the adapter detent 128 is aligned with the groove 137 on the bushing 136. The wide portion 131 of the pear-shaped opening 130 has a diameter which is slightly greater than the diameter of the adapter bushing 136 adjacent to the groove 137, but less than the diameter of the distal end of the adapter bushing 136. Thus, when the adapter detent 128 is positioned such that the wide portion 131 of pear-shaped opening 130 is aligned with the opening 115 in the socket housing cap 114, and thus centered about the adapter bushing 136, the adapter detent 128 is disengaged from the adapter bushing 136. When the adapter detent 128 is in this disengaged position, the adapter bushing 136 may be moved distally out of the adapter detent 128. However, when the groove 137 in the adapter bushing 136 is aligned with the adapter detent 128, the adapter detent 128 may be moved laterally relative to the adapter bushing 136, such that the receiver portion 96 of the adapter detent 128 engages the groove 137. When the adapter bushing 136 is thus engaged by the adapter detent 128, the position of the adapter bushing 136 is axially fixed relative to the adapter detent 128 and thus to the handle 11 to which the adapter assembly 118 is secured. The adapter detent 128 is thus in the engaged position. As indicated above, the shaft portion 12 is releasably secured to the handle 11. To install the shaft portion 12, locking mechanism 78 is first released, to allow the trigger arm 66 to move distally to the first position thereof. Then, the detent 94 and the adapter detent 128 are moved to their disengaged positions. This may be easily accomplished by holding the handle in one hand such that the exposed first bearing portion 95 of the detent 94 is depressed with one finger while flange 129 of the adapter detent 128 is simultaneously depressed by the thumb of the same hand. The adapter assembly 118 may be rotated relative to the handle 11 to the most convenient position for operating the adapter detent 128. With the adapter detent 128 and the detent 94 held in their disengaged positions, the shaft portion 12 is inserted into the opening 130 through the adapter detent 128 with the user's other hand. The actuating member 60 is guided through the contact assembly 105, the trunnion 85, and into the insert 55 in the coupling 45. As indicated above, the distal end of the central opening 115 through the socket housing cap 114 is chamfered to ease the alignment and insertion of the actuating member 60 through the contact assembly 105. The coils of the spring 109 twist as they are pushed out of the way of the actuating member 60 as the actuating member 60 passes through the contact assembly 105. The spring 109 bears against the exterior of the actuating member 60 to provide an electrically conducting contact. As the actuating member 60 is inserted into the coupling 45, the tongue 63 engages the splines 56 on the interior of the insert 55, thus coupling the actuating member 60 for rotation with the motor assembly 29. As the actuating member 60 is inserted into the handle 11, the adapter bushing 136 on the tube 61 is simultaneously inserted into the adapter assembly 118. The shaft portion 12 is inserted until the adapter bushing 136 bears against the distal face of the adapter body 119. The detent 94 can then be released to engage the groove 62 on the actuating member 60, and the adapter detent 128 released to engage the groove 137 on the adapter bushing 136. Thus the shaft portion 12 is installed on the handle 11 with the tube 61 axially fixed relative to the handle 11, and the actuating member 60 is connected to the operating mechanism 19 for reciprocation and rotation relative to the handle 11. As indicated above, rotation of the actuating member 60 to rotate the tool 13 will normally cause the tool 13 to rotate the tube 61. This will cause the adapter bushing 136, which is fixed to the tube 61, to rotate relative to the adapter assembly 118 since the adapter body 119 does not rotate freely relative to the handle 11. To release the shaft portion 12 from the handle 11, the detent 94 and the adapter detent 128 are each moved to their respective disengaged positions. The actuating member 60 and the tube 61 are thus quickly freed to permit removal of the shaft portion 12 from the handle 11. Note that the unique attachment mechanism provided by the detent 94 and the adapter detent 128 permits rapid and simple removal and replacement of the shaft portion 12. This may be desired during the course of surgery, for example, to change from the gripping tool 13 to a scissors tool which would be supported on another shaft portion 12. In previously known instruments, removable shaft portions were secured to respective handles by means of a rotating locking ring, thumb screw, or threaded collar which first had to be rotated to release the shaft portion before the shaft portion could be grasped and removed from the handle. In operation, a user selects the type of tool 13 which is to be used. For the sake of illustration, assume that the user wishes to perform suturing of an internal organ during laparoscopic surgery using a conventional suture needle with an attached ligature or suture. The tool 13 chosen by the user would be a gripper as illustrated in FIGS. 1 and 2. The user then installs the shaft portion 12 having the selected tool 13 onto the handle 11, as described above. Grasping the grip portion 14 of the handle 11 with one hand, the user can use fingers of the same hand to move the trigger arm 66 toward the grip portion 14 and thereby actuate the tool 13 to grasp the suture needle (not shown). The user then actuates the locking mechanism 78 by pressing on the arm 84a of the bell crank lever 84, thus locking the trigger arm 66 in place. This allows the user to release the trigger arm 66 without dropping the suture needle. It will be understood that, as pointed out above, the locking mechanism 78 is capable of securing the position of the trigger arm 66 relative to the handle 11 at any point in the travel of the trigger arm 66. This advantageously permits the instrument 10 to be locked grasping any item within the range capable of being grasped by the tool 13, not merely relatively small objects like a needle. The instrument 10 is then positioned for use by inserting the tool 13 and shaft portion 12 through a laparoscopic guide tube (not shown) installed through a patient's abdominal wall. By manipulating the instrument 10, the user can pass the needle partially through the tissue to be sutured. While gripping the finger grip 70 of the trigger arm 66 with one or two fingers, the user presses on the arm 84b of the lever 84 with another finger, causing the locking mechanism 78 to move the pawl 80 out of engagement with the ratchet 79, and release the trigger arm 66. Since the user was gripping the trigger arm 66, the user can control the rate at which the spring 77 moves the trigger arm back to the first position thereof, causing the tool 13 to release the needle. The tool 13 can then be closed on the protruding portion of the needle to pull it the rest of the way through the tissue, thus pulling the suture fixed to the needle through the tissue. The suture is cut between the tissue and the needle, leaving first and second ends of the suture (not shown) extending from the tissue. The user grasps the first end of the suture in the tool 13. The user depresses a thumb switch 27 or 28 to cause the tool 13 and the tube 61 to rotate three revolutions in a first direction. As discussed above, the microprocessor of the control circuit 25 can be programmed to cause, for example, a full rotation for a single momentary depression of a thumb switch 27 or 28. Simultaneously the user manipulates a second instrument(not shown), which may be a conventional gripper tool, to guide the portion of material between the tissue and the first end of the suture proximally, thus causing the suture to form three wraps around the tube 61. The first end of the suture is then grasped by the second instrument, and the tool 13 operated to release the first end of the suture. The tool 13 is then moved to grasp the second end of the suture, while maintaining the wraps around the tube 61. The instrument 10 and the second instrument are then pulled relatively away from each other, causing the wraps to slide off the tube 61 and down around the second end of the suture. Carefully releasing the first end of the suture so that the wraps remain around the second end of the suture, the user grasps the second end of the suture with the second instrument. Then the user manipulates the instrument 10 to release the second end of the suture and grasp the first end of the suture with the tool 13. The user actuates a thumb switch 27 or 28 to cause the tool 13 rotate in the opposite direction from the first direction, causing a single wrap to form about the tube 61. After exchanging grips once again, without allowing the wrap to slide off the tube 61, the user grasps the second end of the suture in the tool 13, and the first end of the suture with the second instrument. The instruments are then pulled apart again to form a slip knot of a type conventionally used in surgery for securely suturing tissue. Referring now to FIG. 8, a second embodiment of a laparoscopic surgical instrument, indicated generally at 150, in accordance with this invention is shown. The instrument 150 includes a pistol-shaped handle 151, a shaft portion 152 releasably fixed to the distal end of the handle 151, and a tool 153 mounted on the distal end of the shaft portion 152. The handle 151 is preferably constructed of two symmetrical side pieces to form a grip portion 154 and a hollow receiver portion 155, in a manner similar to the handle 11 described above. The handle 151 includes an actuating structure 156, which is structurally similar to the actuating structure 65 described above. The actuating structure 156 includes a trigger arm 157 pivotally mounted on the receiver portion 155 of the handle 151 for movement relative thereto. A spring 158 or other resilient structure is provided for urging the trigger arm 157 to a first position, relatively away from the grip portion 154 of the handle 151. The first position of the trigger arm 157 corresponds to the unactuated condition of the tool 153. As with the first embodiment described above, when the trigger arm 157 is moved toward the handle 151 to a second position relatively closer to the grip portion 154, the tool 153 is actuated. The trigger arm 157 is provided with a releasable locking mechanism, identical in structure and operation to the locking mechanism 78 described above, for selectively retaining the trigger arm 157 in a selected position relative to the grip portion 154. The spring 158 is preferably a leaf spring formed from a curved metallic strap, generally formed as a continuous arc, but having an S-shaped curve 159 near the proximal end thereof. A first opening 160 is formed through the spring 158, spaced slightly from the proximal end thereof. A second opening 161 is formed through the spring 158 near the distal end thereof. A threaded stud 162, which is fixed to the lower end of the grip portion 154 extends through the first opening 161 in the spring 158. A thumbnut 163 is threaded onto the stud 162 to secure the spring 158 to the grip portion 153. Tightening the thumbnut 163 will urge the spring 158 to pivot about a portion of the S-shaped curve 159, urging the trigger arm 157 away from the grip portion 154 of the handle 151. Thus, tightening the thumbnut 163 increases the tension in the spring 158. Conversely, loosening the thumbnut 163 decreases the tension in the spring 158, thus making it easier for a user to move the trigger arm 157 toward the grip portion 154 of the handle 151. In this manner, operation of the thumbnut 163 permits the user to select a desired amount of tension in the spring 158. The spring 158 is coupled to the trigger arm 157 by a link 164. The link 164 is pivotally mounted at a first end thereof in a recess formed on the proximal side of the trigger arm 157. A hook 165 is formed on a second end of the link 164 which engages the opening 161 in the distal end of the spring 158 to couple the link 164 and the spring 158. The spring 158 exerts a force axially through the link 164 to urge the trigger arm 164 away from the grip portion 154 of the handle 151 as described above. As the trigger arm 157 is moved relative to the grip portion 154 of the handle 151, the link 164 pivots to accommodate the resultant relative motion between the distal end of the spring 158 and the trigger arm 164. Referring now to FIG. 9, the receiver portion 155 of the handle 151 has a pair of opposed oval openings 166 (one of which is shown by a broken line) formed through the side pieces thereof. A trunnion 167, identical in structure and function to the trunnion 85 described above, extends through the openings 166 in the receiver portion 155, between the yoke arms of the trigger arm 157. Thus, the trigger arm 157 may be moved to move the trunnion 167 axially within the receiver portion 155. A bore 168 extends through the trunnion 167 coaxially with the receiver portion 155. A cap 169 is fixed to the proximal face of the trunnion 167, sealing the proximal end of the bore 168. A detent 170 is reciprocal within the trunnion 167. The detent 170 has a pear-shaped opening 171 therethrough for releasably engaging the shaft portion 152 as will be further described below. A contact assembly 172, generally similar to the contact assembly 105 described above, includes a generally cylindrical socket housing 173 fixed to the distal face of the trunnion 167 for movement therewith. A proximal socket 174 and a distal socket 175, each of which are identical in structure to the socket 106 described above, are supported within the socket housing 173. A canted coil spring 176, or other suitable means for providing a sliding conductive contact with the shaft portion 152, is captured within a circumferential groove within the bore formed through each of the sockets 174 and 175. An electrically insulating washer 177 is interposed between the sockets 174 and 175. An annular socket housing cap 178 is secured to the distal end of the socket housing 173 to capture the sockets 174 and 175 within the socket housing 173. The central openings of the sockets 174 and 175, the insulating washer 177, and the socket housing cap 178 are coaxially aligned with the bore 168 through the trunnion 167. The sockets 174 and 175 may be electrically energized via respective conductors 179 from a conventional bipolar plug 180 extending through the proximal end wall of the receiver portion 155 of the handle 151. As in the first embodiment, the conductors 179 must be sufficiently long and flexible to accommodate the relative movement between the plug 180 and the contact assembly 172. The handle 151 preferably includes a molded annular guard 181 about the outwardly projecting portion of the plug 180. An adapter assembly 182, similar in structure and function to the adapter assembly 118 described above is rotatably mounted on the distal end of the receiver portion 155. The adapter assembly 182 includes a body 183 having an axial bore 184 therethrough. An adapter detent 185 having a pear-shaped opening 186 therethrough is reciprocally mounted on the body 183. As will be further discussed below, the body 183 is preferably provided with axially-extending grooves 187 to facilitate a user's rotation of the body 183 relative to the receiver portion 155 of the handle 151. Unlike the adapter assembly 118, the adapter assembly 182 includes a pair of opposed conventional ball plungers 188. Each ball plunger 188 is mounted by means of external threads thereon in a respective threaded bore 189 extending radially from exterior of the body 183 to the axial bore 184 through the body 183 of the adapter assembly 182. The spring-loaded balls of each ball plunger 188 extends at least partially into the axial bore 184 of the body 183, for a purpose which will be explained below. As illustrated in FIGS. 8 through 10, the shaft portion 152 of the instrument 150 is generally similar to the shaft portion 12 described above. The shaft portion 152 includes an outer tube 190. The interior surface of the distal end of the tube 190 is threaded for mounting the tool 153. An adapter bushing 191 is fixed about the proximal end of the tube 190. The adapter bushing 191 has a structure which is similar to the adapter bushing 136 described above, being tapered inwardly toward the proximal end thereof, and having a circumferential groove 192 formed near the distal end thereof. A plurality of opposed pairs of semi-spherical recesses 193 are spaced about the circumference of the adapter bushing 136 intermediate the groove 192 and the proximal end of the adapter bushing 136, the purpose of which will be explained below. The shaft portion 152 also includes an actuating member 194 which is axially reciprocal within the tube 190. The proximal end of the actuating member 194 is fixed to a cylindrical connector body 195, preferably by molding the connector body 195 around the distal end of the actuating member 194. The distal end of the actuating member 194 may be knurled or otherwise shaped to improve resistance to being pulled out of the connector body 195. The connector body 195 is provided with a pair of electrical contacts 196 and 197, each made of a suitable electrically conductive material. The contact 196 is generally cylindrical, and has a circumferential groove 198 formed about a portion thereof. A reduced diameter distal portion 199 of the contact 196 extends into the proximal end of the connector body 195. An electrical conductor 200 is electrically connected, for example by soldering, to the distal portion 199 of the contact 196. The contact 197 is generally tubular and is disposed about the distal portion 199 of the contact 196. The contact 197 is swaged or otherwise formed to reduce the diameter of a distal portion 201 of the contact 197. The inner diameter of the distal portion 201 of the contact 197 is greater than the outer diameter of the distal portion 199 of the contact 196, so that the contact 197 is spaced apart from the contact 196. The distal portion 201 of the contact 197 is electrically connected to an electrical conductor 202. The contacts 196 and 197 are held in fixed relationship relative to the actuating member 194 by the connector body 195. The connector body 195 is preferably formed by insert molding an insulating plastic material over the distal portions of the contacts 196 and 197, and over the proximal ends of the conductors 200 and 202, along with the proximal end of the actuating member 194 as described above. Thus the proximal ends of the contacts 196 and 197 are left exposed, the purpose of which will be described below. Referring now to FIG. 10, the distal end of the actuating member 194 is fixed to a cylindrical connector body 203, preferably by insert molding the connector body 203 around the distal end of the actuating member 194. The distal end of the actuating member 194 may be knurled or otherwise shaped to improve resistance to being pulled out of the connector body 203. The conductors 200 and 202 extend through the connector body 203. A pair of spaced apart connecting members 204 and 205 extend axially from the distal end of the connector body 203. The connecting members 204 and 205 are fixed to the connector body 203, preferably by insert molding the connector body 203 about the respective proximal ends of the connecting members 204 and 205. The connecting members 204 and 205 may advantageously be formed from a single U-shaped length of spring wire, the bight (not shown) of which is encased in the connector body 203. The distal end of each of the connecting members 204 and 205 is formed into a respective inwardly extending arm 206 and 207. The connecting members 204 and 205 are bent radially outwardly in opposite directions so that the arms 206 and 207 are transversely offset from one another. The purpose of the arms 206 and 207 will be explained below. As is best seen in FIG. 10, the tool 153 includes a generally tubular body 210. The body 210 is provided with threads on the outer surface of the proximal end thereof which engage the threads formed on the interior surface of the outer tube 190 of the shaft portion 152 to fix the body 210 on the distal end of the shaft portion 152. The body 210 has a pair of axially extending yoke arms 211 (FIG. 8) and 212 (shown in broken line in FIG. 10). A respective pivot hole 214 is formed through each of the yoke arms 211 and 212, the purpose of which will be explained below. The tool 153 further includes a pair of jaws 215 and 216 which are mutually relatively moveable. The jaw 215 includes an elongate gripping portion 217. A metallic contact 218 is fixed to the gripping portion 217. Preferably, the contact 218 is formed by stamping, although other forms of forming the contact 218, such as wire forming are also contemplated. The electrical conductor 202 is electrically connected, for example by soldering, to the contact 218. The gripping portion 217 is preferably formed of an electrically insulating, rigid plastic material which is molded about portions of the contact 218 and the distal portion of the conductor 202 to fix the contact 218 to the gripping portion 217 for a purpose which will be discussed below. A flange 220 is formed on the proximal end of the gripping portion 217, preferably being integrally molded with the gripping portion 217. A pivot pin 221 extends perpendicularly from the flange 220 into the pivot hole 214 (FIG. 8) of the yoke arm 211 adjacent to the jaw 215, the purpose of which will be explained below. An opening 222 is formed through the proximal end of the flange 220, and is engaged by the arm 206 formed on the connecting member 204. The jaw 215 is thus connected to the connector body 203 for actuation thereby. A connector pin 224 extends from the flange 220 opposite the pin 221 to engage a mating recess 225 in a flange 223 formed on the jaw 216 with a snap fit, thereby allowing the jaws 215 and 216 to be coupled together and pivoted relative to one another. Except for the recess 225 described above, the jaw 216 is otherwise constructed similarly to the jaw 215, having a gripping portion 226 formed on the distal end of the flange portion 223. The gripping portion 226 is provided with an exposed contact 227 which is electrically connected to the conductor 200. Note that since the gripping portions 217 and 226 are formed of an electrically insulating material, no current path is provided between the conductors 202 and 200 through the jaws 215 and 216. A second pivot pin (not shown), similar to the pivot pin 221, extends outwardly from the flange portion 223 to engage the pivot hole 214 of the yoke arm 212. The second pivot pin and the pivot pin 221 are coaxially aligned with the connector pin 224 and cooperate with the pivot holes 214 in the respective adjacent yoke arms 212 and 211 to pivotally mount the coupled jaws 215 and 216 to the body 210 of the tool 153. An opening 228 is formed through the proximal end of the flange portion 223, which is engaged by the arm 207 on the connecting member 205. The jaw 216 is thereby connected to the connector body 203 for actuation thereby. The procedure for connecting the shaft portion 152 to the handle 151 is generally the same as that for connecting the shaft 12 to the handle 11 of the first embodiment, as described above. The locking mechanism is first released, to allow the trigger arm 157 to move distally to the first position thereof. Then the detent 170 and the adapter detent 185 are moved to their disengaged positions. The adapter assembly 182 may be rotated relative to the handle 151 to the most convenient position for operating the adapter detent 185. With the adapter detent 185 and the detent 170 held in their disengaged positions, the shaft portion 152 is inserted into the opening 186 through the adapter detent 185 with the user's other hand. The actuating member 194 is guided through the contact assembly 172, the trunnion 167, and into the cap 169. The spring 176 in the socket 174 bears against the electrical contact 196 provide an electrically conducting contact therebetween. Similarly, the spring 176 in the socket 175 bears against the electrical contact 197 to provide an electrically conducting contact therebetween. As the actuating member 194 is inserted into the handle 151, the adapter bushing 191 on the outer tube 190 is simultaneously inserted into the adapter assembly 182. The shaft portion 152 is inserted until the adapter bushing 191 bears against the distal face of the adapter body 183. The detent 170 can then be released to engage the groove 198 on the actuating member 194, and the adapter detent 185 released to engage the groove 192 on the adapter bushing 191. It may be necessary to move the trigger arm 157 slightly to permit the detent 170 to engage the groove 198 on the actuating member 194. The shaft portion 152 is thus installed on the handle 151 with the outer tube 190 axially fixed relative to the handle 151, and the actuating member 194 is connected to the actuating structure 156 for reciprocation with the trigger arm 157. Additionally, the balls of the ball plungers 188 are axially aligned to engage the recesses 193 on the adapter bushing 191. The recesses 193 may be engaged by the ball plungers 188 immediately upon insertion of the shaft portion 152 into the handle 151. However, it may be necessary to rotate the outer tube 190 and the attached adapter bushing 191 relative to the handle 151 to radially align a pair of the recesses 193 with the ball plungers 188. Once the ball plungers 188 are axially and radially aligned with a pair of the recesses 193, the balls of the ball plungers 188 will engage respective ones of the recesses 193. The adapter bushing 191 and the outer tube 190 are thereby releasably fixed to the adapter assembly 182 for rotation therewith. In operation, a user (not shown) will grasp the instrument 150 by the handle 151 with one hand. To rotate the tool 153 to a desired orientation relative to the handle 151, the user grasps and rotates the body 183 of the adapter assembly 182. The grooves 187 provide a relatively slip-resistant surface for grasping the body 183. The ball plungers 188 couple the body 183 to the adapter bushing 191 such that when the body 183 is rotated, the adapter bushing 191 and the outer tube 190 also rotate. The tool 153 is fixed to the outer tube 190 and thus rotates therewith. To actuate the tool 153, the user moves the trigger arm 157 from the first position thereof proximally to a second position relatively closer to the grip portion 154 of the handle 151. The trunnion 167 consequently moves the actuating member 194 proximally within the handle 151, causing the connector body 203 to move proximally relative to the outer tube 190. This in turn causes the connecting members 204 and 205 attached to the connector body 203 to draw the openings 222 and 228 relatively closer together, and the gripping portions 217 and 226 to move toward one another. Releasing the trigger arm 157 permits the spring 158 to drive the trigger arm 157 back toward the first position thereof, resulting in the connector body 203 moving relatively toward the tool 153. This causes the connecting members 204 and 205 to drive the proximal end of flanges 220 and 223 relatively apart and also causes the gripping portions 217 and 226 to move relatively apart. As indicated above, the contacts 218 and 227 are electrically isolated from one another by the respective gripping portions 217 and 226 which are made of an electrically insulating material. A conventional electrosurgical generator having a bipolar electrical potential output may be connected to the instrument 150 via the plug 180. A user may then actuate the tool 153 to grasp selected tissue between the jaws 215 and 216. The user can then actuate the generator to apply an electrical potential between the contacts 218 and 227, thereby causing electrical current to flow through the tissue interposed between the contacts 218 and 227. This may be desired, for example, to cauterize a wound during surgery. Referring now to FIGS. 11 and 12, a third embodiment of a laparoscopic surgical instrument in accordance with this invention is shown generally at 300. The instrument 300 includes a pistol-shaped handle 302, which is preferably constructed of two symmetrical side pieces to form a hollow receiver portion 304, in a manner similar to the handles 11 and 151 described above. The handle 302 includes an actuating structure having a trigger arm 306 pivotally mounted on the receiver portion 304 of the handle 302 for movement relative thereto. The proximal end of the receiver portion 304 is provided with an elongated flange 308 defining a longitudinal axis of the receiver portion 304. The flange 308 has a T-shaped cross section for adjustably mounting a grip portion 310 on the receiver portion 304. As shown in FIG. 12, each half of the receiver portion 304 preferably forms one half of the flange 308. The grip portion 310 is preferably constructed of two symmetrical side pieces, 310a and 310b. Each of the side pieces 310a and 310b is provided with a respective flange 311 which extends about most of the periphery of the respective side piece 310a or 310b, and which extends toward the other of the side pieces 310a and 310b. The flanges 311 on the side pieces 310a and 310b cooperate with the side pieces 310a and 310b to generally define a hollow interior space 312 within the grip portion 310. A discontinuity in the flanges 311 forms a first opening 314 into the grip portion 310. A second opening 316 into the grip portion 310 exposes the T-shaped flange 308 of the receiver portion 304 to the interior space 312 of the grip portion 310, for a purpose which will be discussed below. Each of the side pieces 310a and 310b is provided with a respective longitudinally extending recess, 318a and 318b. The recesses 318a and 318b cooperate to define a T-shaped slot which receives the flange 308 to mount the grip portion 310 for sliding movement relative to the receiver portion 304 along the longitudinal axis defined by the flange 308. Each of the side pieces 310a and 310b is also provided with a respective cylindrical recess, 320a and 320b. The recesses 320a and 320b cooperate to mount a pin 322 therein. A locking mechanism is provided for selectively fixing the relative positions of the grip portion 310 and the receiver portion 304. The locking mechanism includes a locking cam 324. The cam 324 has a disc-shaped body 325 and a depending arm 326, which is eccentrically mounted on the pin 322. The arm 326 extends out of the interior space 312 of the grip portion 310 through the opening 314, where it may be easily manipulated by a user of the surgical instrument 300. In a first position, illustrated in solid line in FIG. 11, the body 325 of the cam 324 is spaced apart from the flange 308, and the grip portion 310 is free to move longitudinally relative to the receiver portion 304 of the handle 302. In this manner, a user of the surgical instrument 300 may adjust the distance between the trigger arm 306 and the grip portion 310 as needed to provide a comfortable grip. Once a position is found which is comfortably fits the size of the user's hand, the arm 326 of the cam 324 is operated to move the cam 324 to the lock position illustrated in dashed line in FIG. 11. As the cam 324 is rotated into the lock position, the eccentrically mounted body 325 is urged through the opening 316 into contact with the flange 308. The cam 324 is wedged against the flange 308 in the lock position, fixing the position of the grip portion 310 on the receiver portion 304. FIGS. 13 and 14 illustrate a fourth embodiment of a laparoscopic surgical instrument, indicated generally at 400, in accordance with this invention. The instrument 400 includes a pistol-shaped handle 402, which is generally similar to the handle 302 described above. The handle 402 includes a receiver portion 404 having a proximal end which is generally cylindrical. The handle 402 also includes a grip portion 406 which is adjustably mounted on the receiver portion 404. Unlike the grip portion 310, the grip portion 406 is provided with a pair of clamp members 410 and 412. Each of the clamp members 410 and 412 has a respective curved wall 414, and a respective ear 416 extending from one longitudinally extending edge of the respective curved wall 414. The curved walls 414 of the clamp members 410 and 412 cooperate to substantially encircle the proximal end of the receiver portion 404. The flat plates 416 of the clamp members 410 and 412 are parallel and spaced apart from one another. Each of the flat plates 416 has an aperture formed therethrough. A pin 418 is fixed in the apertures formed in the flat plates 416 of the clamp members 410 and 412, extending between the flat plates 416. The flat plates 416 of the clamp members 410 and 412 are fixed to respective halves of the grip portion 406 by any suitable means. Note that although the grip portion 406 is preferably formed from two symmetric mating pieces, the grip portion 406 of the laparoscopic surgical instrument 400, as in the other embodiments of the laparoscopic surgical instrument of this invention, may be suitably formed as a unitary part, or formed from any suitable number of parts. Also, the clamp members 410 and 412 may be formed as a single piece, or may be formed as integral parts of respective ones of the two halves of the grip portion 406. A locking mechanism is provided, which includes a locking cam 420. The locking cam 420, similar to the cam 324 described above, is eccentrically mounted on the pin 418. While holding the laparoscopic surgical instrument 400, the user may use his or her fingers to easily move the cam 420 from an unlock position (shown in solid line in FIG. 13) to a lock position (shown in dashed lines in FIG. 13). In the unlock position, the cam 420 is disengaged from the receiver portion 404, and the grip portion 406 may be moved relative to the receiver portion 404. If desired, the grip portion 406 may be rotated relative to the receiver portion 404, as well as being moved longitudinally relative thereto as depicted by the phantom lines of FIG. 13. When the cam 420 is moved to the lock position, the cam 420 moves into engagement with the proximal end of the receiver portion 404, and is wedged between the pin 418 and the receiver portion 404 to fix the position of the grip portion 406 on the receiver portion 404. FIGS. 15 through 17 illustrate a fifth embodiment of a laparoscopic surgical instrument in accordance with this invention, which is indicated generally at 500. The instrument 500 is generally similar to the instrument 400 described above, and has a grip portion 502 adjustably mounted on the cylindrical proximal end of a receiver portion 504. The grip portion 502 is fixed to, or integrally formed with a clamp member 510. The clamp member 510 includes a tubular body 512 encircling the proximal end of the receiver portion 504. A longitudinally extending opening 514 is formed through the body 512 opposite to the grip portion 502. Adjacent each longitudinally extending edge of the opening 514 is a respective outwardly extending ear 516. The ears 516 are parallel to each other, and are spaced apart from one another by the transverse width of the opening 514. A pin 518 is mounted transversely on the clamp 510, extending between the ears 516. A locking mechanism is provided, which includes a locking cam 520. The locking cam 520 is eccentrically mounted on the pin 518. The locking cam 520 is similar in function to the locking cam 420 described above, but mounted on the opposite side of the receiver portion 504 from the grip portion 502 of the instrument 500. The locking cam 520 is shown in an unlock position in FIG. 15. In the unlock position, the cam 520 is disengaged from the receiver portion 504, and the grip portion 502 may be moved relative to the receiver portion 504. If desired, the grip portion 502 may be rotated relative to the receiver portion 504, as well as being moved longitudinally relative thereto as depicted by the phantom lines of FIG. 15. When the cam 520 is moved to the lock position, illustrated in FIG. 15, the cam 520, extending into the opening 514, moves into engagement with the proximal end of the receiver portion 504. The cam 520 is wedged between the pin 518 and the receiver portion 504 to fix the position of the grip portion 502 on the receiver portion 504. The instrument 500 may thus be seen to be very similar in structure and function to the instrument 400, but having the locking cam 520 mounted to engage the upper surface (as seen in FIGS. 15 through 17) of the receiver portion 504 rather than the lower surface thereof. FIGS. 18 and 19 illustrate a sixth embodiment of a laparoscopic surgical instrument in accordance with this invention, which is indicated generally at 600. The instrument 600 is generally similar to the instrument 500 described above, with three exceptions. The proximal end of a receiver portion 604 of the instrument 600 has a generally square cross section, rather than a cylindrical one like the receiver portion 504 described above. The clamp member 610 includes a hollow body 612 also having a generally square cross section loosely conforming to the proximal end of the receiver portion 604. The clamp member 610, and the attached grip portion 614, can thus move longitudinally relative to the receiver portion, but not rotate relative thereto. Finally, instead of a locking cam similar to the cam 520 described above, the clamp member 610 is provided with a thumb screw 616 for a locking mechanism. The thumbscrew 616 engages a threaded opening 618 in the body 612, and may be selectively screwed inwardly to engage the receiver portion 604 to fix the relative positions of the grip portion 610 and the receiver portion 604. The thumb screw 616 may be selectively loosened to reposition the grip portion 610 on the receiver portion 604. It will be appreciated that the opening 618 may be provided to mount the thumb screw 616 at other locations on the body 612. For example the thumb screw could be mounted to extend upwardly through the grip portion 614 as shown in phantom line in FIG. 18, or through the side of the body 614, as shown in FIG. 19. It will be appreciated that the locking cams 420 and 520 described above could be mounted to engage the side of their respective receiver portions. However such an arrangement may be less desirable than the designs illustrated and discussed above, since such an arrangement would likely be less ambidextrous than the discussed designs. FIGS. 20 through 22 illustrate a seventh embodiment of a laparoscopic surgical instrument in accordance with this invention, which is indicated generally at 700. The instrument 700 is generally similar to the instruments described above which have adjustably mounted grip portions. The proximal end of a receiver portion 704 of the instrument 700 has a longitudinally extending flange 706 depending therefrom. Note that although the receiver portion 704 is shown as a single piece, the receiver portion 704 may suitably be formed from two or more pieces fixed together like, for example, the two symmetrical side pieces forming the receiver portion 304 described above. The flange 706 has a cruciform cross section, as shown in FIGS. 21 and 22. As shown in FIG. 20, the lower portion of the flange 706 is scalloped, having a plurality of recesses 708 extending transversely from side to side of the lower surface of the flange 706. The purpose of the recesses 708 will be described below. A grip portion 714, formed from a symmetric pair of mating halves 714a and 714b, is slidably mounted on the flange 706. Each of the halves 714a and 714b is formed with respective longitudinally extending recess 716. The recesses 716 cooperate to form a cruciform slot within which the flange 706 is slidably received. Each half 714a and 714b of the grip portion 714 is formed with a respective cylindrical recess, the two cylindrical recesses cooperating to define a transversely extending cylindrical bore 718 in the grip portion 714. At each end of the cylindrical bore 718, a square opening (or other non-circular opening) 720 extends through the respective half 714a and 714b of the grip portion 714. A locking pin 722 is slidably disposed within the bore 718. The locking pin 722 has a cylindrical central portion 724. The central portion 724 is shorter in length than the bore 718, so that the locking pin 722 can slide in the bore 718 between a first position, shown in FIG. 21, and a second position, shown in FIG. 22. A pair of extensions 726 and 728 are formed on respective ends of the central portion 724. The extensions 726 and 728 have square cross sections, and extend into respective ones of the openings 720. The openings 720 cooperate with the extensions 726 and 728 to prevent the locking pin 722 from rotating within the bore 718. A user of the instrument 700 can move the locking pin 722 transversely to the first position by pressing against the extension 726, which extends outwardly from the grip portion 714 when the locking pin 722 is not in the first position. The user can move the locking pin 722 to the second position by pressing against the extension 728, which extends outwardly from the grip portion 714 when the locking pin is not in the second position. The central portion 724 of the locking pin 722 has a notch 730 which extends longitudinally (with respect to the axis of the receiver portion 704 of the instrument 700) through the upper part (as viewed in FIGS. 21 and 22) of the central portion 724 of the locking pin 722. When the locking pin 722 is placed in the first position, the notch 730 is aligned with the flange 706, as shown in FIG. 21, and the grip portion 714 may be selectively moved longitudinally along the flange 706. The grip portion 714 may be selectively locked in place by the user by aligning the locking pin 722 with one of the transverse recesses 708 formed in the flange 706, and then pressing the extension 728 to move the locking pin to the second position shown in FIG. 22. An unnotched upper part of the central portion 724 of the locking pin 722 is moved into the selected one of the recesses 708, thereby preventing longitudinal movement of the grip portion 714 relative to the receiver portion 704. To unlock the grip portion 714, the user presses against the extension 726, moving the locking pin 722 back to the first position, and aligning the notch 730 with the flange 706. With the notch 730 of the locking pin 722 aligned with the flange 706, the portions of the flange 706 between the recesses 708 slide through the notch 730. The locking pin 722 will preferably fit within the bore 718 with a tight sliding fit, so that friction will hold the locking pin 722 in the position selected by the user. However, if necessary the locking pin 722 can be provided with a circumferentially extending groove within which an O-ring 750 is mounted. The O-ring 750 is compressed between the locking pin 722 and the wall of the bore 718 to increase the friction therebetween. It will be understood that the locking mechanism may be formed with a locking pin which prevents relative movement between the grip portion 714 and the receiver portion 704 in other ways than described above. For example, if a locking pin were provided with an enlarged head (not shown) extending from one end thereof, the locking pin could be moved between a first, unlocked position and a second, locked position by manipulating only the enlarged head. Such a locking pin need not extend completely through the receiver portion 704, but could engage a selected one of a plurality of recesses (not shown) formed on an adjacent side of the flange 706. Such recesses could extend completely through the flange 706 to form bores (not shown) in which such a locking pin could be selectively inserted. FIGS. 23 through 28 illustrate an eighth embodiment of a laparoscopic surgical instrument according to the invention and indicated generally at 800. A handle portion 802 of the instrument 800 is provided with a grip portion 804 which is adjustably mounted on a receiver portion 806. The receiver portion 806 has a depending flange 808, similar to the flange 308, which has a T-shaped cross section and which cooperates with longitudinally extending recesses (not shown, but similar to the recesses 318a and 318b described above) to adjustably mount the grip portion 804 on the receiver portion 806. An L-shaped locating pin 810 is fixed to the receiver portion 806. The locating pin 810 has a notched portion 812 which extends parallel to the flange 808. The notched portion 812 of the locating pin 810 has a plurality of circumferentially extending notches 814 formed thereon, as best seen in FIGS. 24 and 25. The grip portion 804 is provided with a locking mechanism 816 for selectively engaging the notches 814 on the locating pin 810, thereby selectively fixing the relative positions of the grip portion 804 and the receiver portion 806. The locking mechanism 816 may be easily operated by the user of the instrument 800 to disengage the notches 814 to permit the grip portion 804 to be moved longitudinally on the flange 808 to a suitable position relative to the receiver portion 806. As best seen in FIGS. 25 through 28, the latch mechanism 816 includes two parallel disks 820 and 822. The disks 820 and 822 are arranged in the grip portion 804 on either side of the locating pin 810. The disks 820 and 822 are identical, and the reference numbers assigned to features on the disk 822 described below will also be used to indicated corresponding features on the disk 820. A finger pad 824 is formed on the outer surface of the disk 822. Three spring retaining pins 826 are fixed to the inner surface of the disk 822 and extend perpendicularly therefrom, the pins 826 being equally spaced about the periphery of the inner surface of the disk 822. A grasper attachment pin 828 is fixed to the inner surface disk 822, and extends perpendicularly therefrom. A coil spring 830 is seated about each of the spring retaining pins 826 on the disks 820 and 822. The springs 830 act to urge the disks 820 and 822 apart. A disk shaped grasper plate 832 is operatively coupled to the disk 822, and another grasper plate 834, identical to the plate 832, is operatively coupled to the disk 820 for movement therewith. Each of the plates 832 and 834 is provided with a longitudinally extending groove 836 on the inner surface thereof. The plate 832 has a first bore 838 formed therethrough into which the grasper attachment pin 828, extending from the disk 822, is fixed, such as by pressing. The grasper attachment pin 828 couples the plate 832 and the disk 822 with the inner face of the plate 832 facing the inner face of the disk 822. The plate 834 has a similar first bore 840 formed therethrough. The associated grasper attachment pin 828 is fixed in the bore 840 to couple the plate 834 and the disk 820 with the inner face of the plate 834 facing the disk 820. The plate 832 has a second bore 842, of slightly greater diameter than the first bores 838 and 840. The grasper attachment pin 828 coupling the plate 834 to the disk 820 is slidably disposed within the second bore 842. Similarly, the plate 834 has a second bore 844, of the same size as the bore 842, through which passes the grasper attachment pin 828 coupling the plate 832 to the disk 822. Each of the grasper plates 832 and 834 is provided with a longitudinally extending groove 846 formed in the inner face thereof. The grooves 846 each have a semicircular cross section so that when the plates 832 and 834 are pressed against one another, as shown in FIG. 26, the grooves 846 cooperate to form a generally cylindrical bore, within which the locating pin 810 extends. An inwardly extending flange 848 is formed in each of the grooves 846, which as shown in FIG. 25, can be positioned in a manner described below to engage one of the notches 814 of the locating pin 810. As depicted in FIG. 26, the springs 830 urge the disks 820 and 822 apart. The grasper plates 834 and 832 are coupled to the associated disks 820 and 822, and are thus urged together such that their respective inner faces are in contact. The flange 848 on each of the grasper plates 834 and 832 is held in a selected one of the notches 814 on the locating pin 810. To move the grip portion 804 relative to the receiver portion 806, the finger pads 824 of the locking mechanism 816 are pressed toward each other by the user, compressing the springs 830. This causes the grasper plates 832 and 834 to be moved apart from one another, as shown progressively in FIGS. 27 and 28. When the flanges 848 are fully disengaged from the notch 814, the grip portion 804 may be moved along the flange 808 to a desired position. When the flanges 848 are next to the notch 814 corresponding to the desired position of the grip portion 804 on the receiver portion 806, the finger pads 824 of the locking mechanism 816 are released. The springs 830 urge the flanges 848 into the selected notch 814. If the finger pads are released in a slightly wrong position, the flanges 848 may engage the locating pin 810 between the notches 814. In this situation, the grip portion 804 may be pushed longitudinally along the flange 808 until the flanges 848 snap into the selected notch 814 under the urging of the springs 830. Note that it is contemplated that a locating pin (not shown) similar to the locating pin 810 could be fixed to the moveable grip portion 804. Likewise, a locking mechanism (not shown) similar to the locking mechanism 816 could be mounted on the receiver portion 806 and cooperate with the locating pin on the grip portion 804 to selectively prevent movement of the grip portion 804 relative to the receiver portion 806. FIGS. 29 and 30 illustrate a ninth embodiment of a laparoscopic surgical instrument according to the invention and indicated generally at 900. A handle portion 902 of the instrument 900 is provided with a grip portion 904 which is adjustably mounted on a receiver portion 906. The grip portion 904 has a flange 908 formed thereon. The flange 908 has a T-shaped cross section and cooperates with a mating slot 910 to mount the grip portion 904 on receiver portion 906. The slot 910 extends along a longitudinal axis in the lower surface of the distal end of the receiver portion 906. Serrated teeth 912 are formed on the underside of each arm of the flange 908 on the grip portion 904, with mating teeth 914 formed on the adjacent surfaces of the slot 910 formed in the receiver portion 906. A leaf spring 916, or other suitable spring, is fixed to the upper surface of the flange 908, urging the teeth 912 into engagement with the teeth 914. Axial movement of the grip portion 904 on the receiver portion 906 is thereby prevented by the locking mechanism comprised of the spring 916 and the teeth 912 and the teeth 914. To adjust the position of the grip portion 904 on the receiver portion 906, a user presses the grip portion 904 toward the receiver portion 906, compressing the spring 916, and disengaging the teeth 912 from the teeth 914. While continuing to compress the spring 916, the grip portion 904 may be moved to a desired position on the distal end of the receiver portion 906 and released, causing the teeth 912 and the teeth 914 to mesh to fix the grip portion 904 in the selected position. As the teeth 912 and the teeth 914 mesh, the grip portion 904 may move slightly from the selected position, in order to reach full engagement of the teeth. The amount of this movement is dependent upon the pitch of the teeth 912 and the teeth 914. In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.

A surgical instrument including a handle adapted to releasably engage a shaft mounting a tool having relatively moveable parts. The handle is provided with an actuating structure which includes a trigger arm selectively moveable relative to the handle to cause concurrent movement of the relatively moveable parts of the tool. The actuating structure may include a locking mechanism for releasably fixing the position of the trigger arm relative to the handle, thus releasably fixing the relative positions of the moveable parts of the tool. The handle is also provided with an operating mechanism which is operatively coupled to the tool to selectively rotate the tool relative to the handle. The operating mechanism may be motorized. The operating mechanism may include a control circuit which can be programmed to activate the motor to rotate the tool through specific intervals of displacement is a chosen direction according to selective manipulations of control switches. The handle may be provided with an adjustable grip. The adjustable grip includes a grip portion which is repositionable relative to the rest of the handle for adjustment of the distance between the trigger arm and the grip portion, to provide the most comfortable grip for users regardless of hand size.

BACKGROUND OF THE INVENTION [0001] 1. Field of Invention [0002] This invention is directed to systems, methods and structures for manipulating the airflow resulting from fluid ejector carriage motion in fluid ejection devices. [0003] 2. Description of Related Art [0004] A variety of systems, methods, structures and/or devices are conventionally used to remove mist which is generated during the operation of fluid ejection devices, such as, for example, ink jet printers. In fluid ejection systems, mist removal is recognized as a significant problem. Very small residual droplets of fluid, such as, for example, ink in ink jet printers, are produced during the fluid ejection process. The residual droplets get caught up in the airflow generated by fluid ejector carriage motion. The residual droplets land indiscriminately, over a period of time, on internal surfaces of the fluid ejection devices. The film left by the residual droplets coats various internal surfaces of the fluid ejection device resulting in, not only cleanliness issues, but also impact to the operation of the fluid ejection device. Specifically, when the film that results from dry residual droplets accumulating on structures along which the carriage is designed to translate, such as, for example, fluid ejector carriage guide rods, the film can impede carriage motion. Additionally, accumulation on various internal sensors degrades the performance of these sensors. [0005] The conventional solution for dealing with mist removal is to add separate, often electrically-driven, fans that can include filters. The disadvantages associated with the addition of separate fans include additional weight and/or structure, greater noise, and increased potential for failure, as well as increased cooling and energy requirements to support the additional fans and like devices. [0006] A variety of systems, methods, structures and/or devices are conventionally used to dissipate heat in thermal fluid ejector modules of fluid ejection devices. The thermal fluid ejector modules of fluid ejection devices, such as, for example, ink jet printers, generate significant amounts of residual heat as the fluid is ejected by heating the fluid to the point of vaporization. This residual heat changes the performance, and ultimately the ejection quality, if the heat remains within the fluid ejector module. During lengthy operation or heavy coverage ejection, the temperature of the thermal fluid ejector module can exceed an allowable temperature limit. Once the temperature limit is exceeded, a slow down or cool down period is normally required to maintain ejection quality. [0007] Many fluid ejection devices, such as, for example, printers, copiers and the like, improve throughput by improving thermal performance. Various techniques are used to remove heat from the fluid ejector module. These techniques include: diverting excess heat into the fluid being ejected; using heat sinks to conduct heat away from the fluid ejector module; and, as with residual mist removal, adding separate fans to increase the total volume of air circulating throughout the fluid ejection device facilitating additional cooling. [0008] Improving heat transfer away from fluid ejection elements can be accomplished by directing flow of ambient air through the fluid ejector carriage and across the heater elements of the fluid ejection module housed in the carriage, and additionally across heat sinks, when installed. U.S. Pat. No. 6,382,760 to Peter, incorporated herein by reference in its entirety, discloses various exemplary embodiments of structures and/or devices for the manipulation of airflow through a fluid ejector carriage for cooling the heater elements and heat sinks. [0009] A variety of systems, methods, structures and/or devices are conventionally used to dry the fluid deposited on a receiving medium by fluid ejection devices and/or to set certain “hot melt” fluids deposited on a receiving medium in a semi-molten state. Print quality in fluid ejection printer devices is enhanced when the fluid ejected onto the receiving medium is rapidly dried and/or set. Again here, separate fans usable to force airflow across the receiving medium have conventionally facilitated this function. [0010] In all cases, the addition of separate fans for mist removal, fluid ejection element cooling, and receiving medium drying results in the disadvantages of additional weight, size, noise, heat production, and/or energy required in the fluid ejection device. SUMMARY OF THE INVENTION [0011] This invention provides systems, methods and structures for manipulating the airflow resulting from fluid ejector carriage motion. [0012] This invention separately provides systems, methods and structures for containing the sweep path of a fluid ejector carriage as the fluid ejector carriage is driven in a substantially reciprocating fashion along structures upon which the fluid ejector carriage translates, such as, for example, carriage guide rods and/or rails. [0013] This invention is separately directed to systems, methods and structures for improving mist removal, fluid ejector element cooling and fluid drying/setting in fluid ejection devices. [0014] In various exemplary embodiments of the systems, methods and structures according to this invention, the fluid ejector carriage sweep path is enclosed by forming the interior cavity of the fluid ejection device to closely surround a fluid ejector carriage containing at least one fluid ejection module and structures upon which the fluid ejector carriage translates, such as, for example, carriage guide rods and/or rails. For ease of understanding and depiction, guide rods and/or rails will be shown and referred to as exemplary structures upon which a fluid ejector carriage translates. It should be appreciated, however, that the use of the terms guide rods and/or rails throughout is intended to be exemplary only and in no way limiting to the embodiment of any structure upon which a fluid ejector carriage translates. [0015] In various exemplary embodiments of the systems, methods and structures according to this invention, the interior cross-sectional area of a resulting sweep path containment is sized such that it closely fits the silhouette of the sides of the fluid ejector carriage as manufactured or as modified with the addition of separate conforming structures. [0016] In various exemplary embodiments of the systems, methods and structures according to this invention, the sweep path containment is generally closed on all sides, except for the face bounded by the receiving medium, and vented to a specific receiving area adjoining the containment or vented outside the fluid ejection device within which it is contained. The resulting effect is the ability to manipulate the airflow generated by fluid ejector carriage motion in order to accomplish one or more beneficial purposes. [0017] In various exemplary embodiments of the systems, methods and structures according to this invention, containment of the fluid ejector carriage sweep path is accomplished by specifically molding or manufacturing the internal surfaces of existing fluid ejection device components, such as, for example, casings and/or covers, to substantially enclose the fluid ejector carriage sweep path to contain airflow therein. In various exemplary embodiments of the systems, methods, and structures according to this invention, separate structures, such as, for example, shrouds, and/or individual panels may be inserted in the vicinity of the fluid ejection carriage to form a sweep path containment. [0018] In various exemplary embodiments of the systems, methods and structures according to this invention, the cross-sectional area of the sweep path containment should conform as nearly as possible with the cross-sectional profile, or silhouette, of the fluid ejector carriage as manufactured or as augmented. [0019] In various exemplary embodiments of the systems, methods and structures according to this invention, the silhouette of the sides of the fluid ejector carriage can be manipulated, shaped and/or enlarged to fit the internal cross-sectional profile of the fluid ejector sweep path containment by molding or manufacture, or, for example, with the addition of appropriately sized and shaped lightweight baffles to the sides of the fluid ejector carriage. [0020] In various exemplary embodiments of the systems, methods and structures according to this invention, openings, such as, for example, vents and/or channels, are provided at either end of the fluid ejector carriage sweep path containment to channel air from the fluid ejector carriage sweep path containment to outside the fluid ejection device. The fluid ejector carriage, conforming in silhouette to the internal cross-sectional area of the fluid ejector carriage sweep path containment, acts as a piston to draw air in through the opening at one end of the containment while expelling air through the opening at the other end of the containment to facilitate mist removal. [0021] In various exemplary embodiments of the systems, methods and structures according to this invention, simple channels usable to direct the exhausted air out through the top, bottom, back, or front of the fluid ejection device are added. In various exemplary embodiments of the systems, methods and structures according to this invention, filters are added in proximity to the openings. [0022] In various exemplary embodiments of the systems, methods and structures according to this invention, openings, such as, for example, vents and/or channels, are added to the fluid ejector carriage to allow air to flow through the fluid ejector carriage to be drawn past heater elements, and/or installed heat sinks, if any, contained in the fluid ejector carriage to facilitate cooling. [0023] In various exemplary embodiments of the systems, methods and structures according to this invention, at least one additional opening in the face of the fluid ejector carriage that houses or mounts the fluid ejection module may be introduced. Airflow exhausted through such opening facilitates drying and/or setting the fluid deposited on the receiving medium. [0024] It should be appreciated that the functions of mist removal, fluid ejector cooling and fluid drying/setting can be accomplished as individual tasks, or in any combination, based on the manipulation of the airflow accomplished in the various embodiments of systems, methods and structures according to this invention. [0025] These and other features and advantages of the disclosed embodiments are described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems, methods and structures according to this invention. BRIEF DESCRIPTION OF THE DRAWINGS [0026] Various exemplary embodiments of the invention will be described in detail, with reference to the following figures, wherein [0027] FIG. 1 illustrates a first exemplary embodiment of a fluid ejector carriage sweep path containment, and a fluid ejector carriage, usable with various exemplary embodiments of the systems, methods and structures according to this invention; [0028] FIGS. 2 A-B illustrate a first exemplary embodiment of a fluid ejector carriage usable with various exemplary embodiments of the systems, methods and structures according to this invention; [0029] FIG. 3 illustrates a bottom view of a first exemplary embodiment of a fluid ejector carriage usable with various exemplary embodiments of the systems, methods and structures according to this invention; [0030] FIG. 4 illustrates a side view of a first exemplary embodiment of a fluid ejector carriage in a fluid ejector carriage sweep path containment usable with various exemplary embodiments of the systems, methods and structures according to this invention; [0031] FIGS. 5 A-B are schematic diagrams illustrating a first exemplary embodiment of an airflow pattern to support mist removal from a fluid ejector carriage sweep path containment; [0032] FIGS. 6 A-B are schematic diagrams illustrating a second exemplary embodiment of an airflow pattern to support mist removal from a fluid ejector carriage sweep path containment; [0033] FIG. 7 illustrates a second exemplary embodiment of a fluid ejector carriage usable with various exemplary embodiments of the systems, methods and structures according to this invention; [0034] FIG. 8 illustrates a bottom view of a second exemplary embodiment of a fluid ejector carriage usable with various exemplary embodiments of the systems, methods and structures according to this invention; [0035] FIG. 9 illustrates a side view of a second exemplary embodiment of a fluid ejector carriage in a fluid ejector carriage sweep path containment usable with various exemplary embodiments of the systems, methods and structures according to this invention; [0036] FIGS. 10 A-B are schematic diagrams illustrating a first exemplary embodiment of an airflow pattern to support fluid ejection element cooling through the fluid ejector carriage; [0037] FIGS. 11 A-B are schematic diagrams illustrating a second exemplary embodiment of the airflow pattern to support fluid ejection element cooling through the fluid ejector carriage; [0038] FIGS. 12 A-B are schematic diagrams illustrating a first exemplary embodiment of an airflow pattern to support drying the ejected fluid onto receiving medium; [0039] FIG. 13 illustrates a side view of a third exemplary embodiment of a fluid ejector carriage in a fluid ejector carriage sweep path containment usable with various exemplary embodiments of the systems, methods and structures according to this invention; and [0040] FIG. 14 illustrates a fourth exemplary embodiment of a fluid ejector carriage usable with various exemplary embodiments of the systems, methods and structures according to this invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0041] The following detailed description of various exemplary embodiments of the fluid ejector carriage sweep path containment and conforming fluid ejector carriage systems according to this invention may refer to and/or illustrate one specific type of fluid ejection system, an ink jet printer, for the sake of clarity and familiarity. However, it should be appreciated that the principles of this invention, as outlined and/or discussed below, can be equally applied to any known, or later-developed, fluid ejection system beyond the ink jet printer specifically discussed herein. [0042] Various exemplary embodiments of the systems, methods and structures according to this invention enable the manipulation of airflow generated by fluid ejector carriage motion in devices, such as, for example, ink jet printers, copiers and/or facsimile machines, to at least one beneficial purpose. These beneficial purposes include: removing residual fluid mist generated in the fluid ejection process; cooling fluid ejector elements heated in the fluid ejection process; drying the fluid deposited on a receiving medium during the fluid ejection process; setting hot melt fluid deposited on a receiving medium during the fluid ejection process; and/or any other purpose wherein it would be advantageous to direct airflow created by the reciprocating motion of a fluid ejector carriage, such as, for example, to supplement or replace separate fans installed to induce airflow for such purpose. [0043] In the various exemplary embodiments of the systems, methods and structures according to this invention, random airflow generated by fluid ejector carriage motion is contained and focused such that increased efficiency is gained with each sweep of the fluid ejector carriage within a fluid ejector carriage sweep path containment to accomplish one or more beneficial purposes. While 100% efficiency in movement and resultant manipulation of the airflow in the sweep path containment is not achievable, particularly in consideration of the requirement for access of the fluid ejection elements to the receiving medium, it is desirable to reduce random leakage from the fluid ejector carriage sweep path containment to the greatest extent. It is further desirable to maintain generally strict tolerances between the silhouette of the fluid ejector carriage and the internal faces of the fluid ejector carriage sweep path containment in order that, with each sweep of the fluid ejector carriage, a maximum percentage of the volume of the air contained within the fluid ejector sweep path containment is manipulated to at least one beneficial purpose. These tolerances, however, should not be designed, manufactured or molded so strictly to risk contact between the fluid ejector carriage and the internal surfaces of the fluid ejector carriage sweep path containment. Such contact would impede fluid ejector carriage motion, produce unintentional frictional drag, and/or generate unwanted noise within the fluid ejection device. [0044] FIG. 1 illustrates a first exemplary embodiment of a fluid ejector carriage sweep path containment 100 , and a fluid ejector carriage 200 , usable with various exemplary embodiments of the systems, methods and structures according to this invention. As shown in FIG. 1 , the fluid ejector carriage sweep path containment 100 substantially encloses the fluid ejector carriage 200 and the structures upon which the fluid ejector carriage 200 translates, such as, for example, carriage guide rods and/or rails 250 , in a generally reciprocating motion. [0045] In various exemplary embodiments of the systems, methods and structures according to this invention, the fluid ejector carriage sweep path containment 100 is formed from a plurality of individual elements which combine to substantially enclose the fluid ejector carriage 200 and structures upon which the fluid ejector translates. For simplicity, clarity and ease of explanation, the depicted embodiment of the fluid ejector carriage sweep path containment 100 is substantially a box-like containment structure that includes a bottom panel 110 , end panels 120 , a front panel 130 , a back panel 140 (removed in FIG. 1 ) and a fixed or movable top panel 150 . It should be appreciated that the fluid ejector carriage sweep path containment can be of any shape or size as long as the essential characteristic of generally maximum airflow manipulation is maintained. It should be appreciated further that the individual panel elements 110 / 120 / 130 / 140 / 150 , which combine to embody the fluid ejector carriage sweep path containment 100 , may be permanent or temporary, fixed or movable, individual elements. Additionally, the individual panel elements 110 / 120 / 130 / 140 / 150 may be molded individually into the structure of the housing of the fluid ejection device or secured to the internal structure of the fluid ejection device in various exemplary combinations. [0046] In various exemplary embodiments of the systems, methods and structures according to this invention, at least one full-span slotted opening (not shown), as will be described below, usable to provide access for fluid ejection from the fluid ejector elements housed in the fluid ejector carriage 200 to the receiving medium, is included. [0047] In various exemplary embodiments of the systems, methods and structures according to this invention, the motion of the fluid ejector carriage 200 , as it translates along at least one structure inside the fluid ejector carriage sweep path containment 100 , creates airflow that can be manipulated to beneficial purposes as described in detail below. [0048] In the various exemplary embodiments of the systems, methods and structures according to this invention, openings 300 usable to facilitate desired airflow patterns are added. It should be appreciated that, though depicted in FIG. 1 as located in the end panels 120 , these openings can be located anywhere, generally at either end of the carriage sweep path, to facilitate desired airflow through and out of the fluid ejector carriage sweep path containment 100 . In various exemplary embodiments of the systems, methods and structures according to this invention, the openings 300 are completely unobstructed holes, or are in the form of vents with louvers, screen and/or other such structures added. As will be detailed below, the openings 300 may include filters usable to trap mist or other contaminants. Also, separate structures, such as, for example, channels, ducting, accordion-style bellows and/or other enclosures usable to direct exhaust air to specific areas inside or outside the fluid ejection device may be added. [0049] FIGS. 2 A-B illustrate a first exemplary embodiment of a fluid ejector carriage 200 usable with various exemplary embodiments of the systems, methods and structures according to this invention. As shown in FIG. 2 , the fluid ejector carriage 200 includes a receiving area 210 to house the elements of at least one fluid ejection system. In various exemplary embodiments of the systems, methods and structures according to this invention, fluid ejection elements are mounted to a platform 215 . The fluid ejector carriage 200 also includes at least one housing 220 which houses at least one interface structure to provide interface between the fluid ejector carriage and the structure upon which the fluid ejector carriage translates. In cases where these structures are guide rods, the interface structures are then referred to and depicted, in exemplary manner, as fluid ejector carriage rod guides 225 . While depicted in FIG. 2 as a single separate housing 220 , it should be appreciated that the housing 220 need not be a separate compartment internal to the fluid ejector carriage 200 . Rather, any structure to facilitate passage of at least one structure upon which fluid ejector carriage translates (not shown) through the fluid ejector carriage 200 , while leaving generally intact the silhouette of the sides of the fluid ejector carriage 200 such that they conform to the overall cross-sectional size and shape of the inside of the fluid ejector carriage sweep path containment, depicted in FIG. 1 as element 100 , may be included. [0050] In various exemplary embodiments of the systems, methods and structures according to this invention, the fluid ejector carriage 200 has a top face 230 , a front face 232 , a rear face 234 , side faces 236 and 238 , and a bottom face 240 . It should be appreciated that the side faces 236 and 238 are necessary to the operation of the invention as described herein. These side faces 236 and 238 conform in silhouette, shape and size to the internal cross-section of the fluid ejector carriage sweep path containment 100 . In various exemplary embodiments of the systems, methods and structures according to this invention, faces 230 , 232 , 234 and 240 may be present or absent as fixed or movable structures as are necessary for the structural integrity of the fluid ejector carriage 200 , or for securing the fluid ejection elements therein, while providing access for servicing and/or replacement of these elements in the fluid ejector carriage 200 . [0051] FIG. 3 illustrates a bottom view of a first exemplary embodiment of a fluid ejector carriage 200 usable with various exemplary embodiments of the systems, methods and structures according to this invention. As shown in FIG. 3 , the fluid ejector carriage 200 is mounted on at least one structure upon which the fluid ejector carriage translates, such as, for example, at least one fluid ejector carriage guide rod 250 and between front and back panels 130 and 140 of the fluid ejector carriage sweep path containment 100 (depicted in FIG. 1 ). At least one fluid ejector element 265 (enlarged for clarity) is mounted on a face of the fluid ejector carriage 200 to deposit fluid on a receiving medium (not shown) as the fluid ejector carriage 200 translates along the at least one fluid ejector carriage guide rod 250 in direction A. It should be appreciated that, though depicted in FIG. 3 as mounted on the bottom face 240 of the fluid ejector carriage, the fluid ejector element 265 could be mounted on, or integral to, any face, front, top, bottom, or back of the fluid ejector carriage 200 that would facilitate access through the corresponding front, top, bottom, or back of the fluid ejector carriage sweep path containment 100 to accomplish fluid ejection from the fluid ejector element 265 onto the receiving medium. [0052] In various exemplary embodiments of the systems, methods and structures according to this invention, the gap between the fluid ejector carriage 200 and the internal faces of the fluid ejector carriage sweep path containment, represented in FIG. 3 by the front panel 130 and the back panel 140 , is generally minimized to promote nearly complete airflow manipulation, minimizing leakage around the fluid ejector carriage 200 , as the fluid ejector carriage 200 translates along the at least one fluid ejector carriage guide rod 250 in direction A. [0053] FIG. 4 illustrates a side view of a first exemplary embodiment of a fluid ejector carriage 200 in a fluid ejector carriage sweep path containment usable with various exemplary embodiments of the systems, methods and structures according to this invention. As shown in FIG. 4 , the fluid ejector carriage 200 is surrounded by the panels 110 , 130 , 140 and 150 of the fluid ejector carriage sweep path containment. The gap between the internal faces of the fluid ejector carriage sweep path containment panels 110 / 130 / 140 / 150 and the fluid ejector carriage 200 is generally minimized on all sides to facilitate as complete airflow movement on either side of, and to minimize leakage past, the fluid ejector carriage 200 as the fluid ejector carriage 200 translates along the at least one structure or fluid ejector carriage guide rod 250 depicted in FIG. 3 . [0054] In the various exemplary embodiments of the systems, methods and structures according to this invention, the side faces 236 / 238 of the fluid ejector carriage 200 , conforming in size and shape to the internal cross-sectional area of the fluid ejector carriage sweep path containment, are solid to facilitate the manipulation of the air within the fluid ejector carriage sweep path containment completely external to the fluid ejector carriage 200 , as will be described below. It should be appreciated that, although depicted for simplicity and clarity as having a generally rectangular silhouette, the silhouette of the fluid ejector carriage 200 could embody any simple or complex shape, or combination of shapes, and may include at least one protrusion or extension as a structure to facilitate alignment of the fluid ejector carriage in the fluid ejector carriage sweep path containment. For example, see the complex shape illustrated in FIG. 13 . In the various exemplary embodiments of the systems, methods and structures according to this invention, the plurality of panels or structures which combine to form the fluid ejector carriage sweep path containment are molded or manufactured such that the internal surfaces of the plurality of panels substantially enclose a volume with a cross-sectional area that conforms in shape and is slightly larger in size than the simple or complex silhouette of the side faces 236 / 238 of the fluid ejector carriage. [0055] In the various exemplary embodiments of the systems, methods and structures according to this invention, a slot 115 is included to provide access for the fluid ejector element 265 to the receiving medium 500 . The slot 115 generally traverses the entire length of a face, for example, the bottom face 110 as depicted in FIG. 4 , of the fluid ejector carriage sweep path containment. The receiving medium 500 is separately moved past the fluid ejector carriage sweep path containment in a direction generally perpendicular to the motion of the fluid ejector carriage 200 such that, with each successive sweep of the fluid ejector carriage 200 along the at least one fluid ejector carriage guide rod 250 (depicted in FIG. 3 ), fluid is ejected in a plurality of generally parallel lines or fields onto the receiving medium 500 . It should be appreciated that, though depicted in FIG. 4 as being mounted on the bottom face of the fluid ejector carriage 200 , the fluid ejector element 265 necessary for ejecting fluid onto the receiving medium may be mounted on, or integrally into, any face, front, top, bottom or back, of the fluid ejector carriage 200 . The slot 115 which provides access for the fluid ejector element 265 to the receiving medium 500 is present in corresponding position on the fluid ejector carriage sweep path containment. [0056] The width of the slot 115 which provides access for the fluid ejector element 265 to the receiving medium 500 does provide the opportunity for leakage of the manipulated airflow based on carriage motion from the fluid ejector carriage sweep path containment. This leakage is, however, minimized as the receiving medium 500 provides a boundary that effectively closes the slot 115 in the bottom face 110 . It should be appreciated that, in conventional systems, fluid throw distance from a fluid ejector element to a receiving medium is generally about 2.5 mm or less. The slight gap between the open face 110 of the fluid ejector carriage sweep path containment 100 and the receiving medium 500 results in the receiving medium effectively acting as the airflow boundary to contain the manipulated airflow produced by carriage motion on this side of the fluid ejector sweep path containment 100 . [0057] FIGS. 5 A-B are schematic diagrams illustrating a first exemplary embodiment of the airflow pattern to support mist removal from the fluid ejector carriage sweep path containment 100 . As the fluid ejector carriage 200 translates along at least one structure (not shown) inside the fluid ejector carriage sweep path containment 100 in direction X, air is drawn in through opening 300 into the airflow zone R and is expelled through opening 300 from airflow zone S in the direction shown by the arrows in FIG. 5A . As fluid is ejected by the fluid ejection system onto the receiving medium, residual droplets are formed and trail the fluid ejector carriage 200 in the area of the intake airflow zone R. When fluid ejector carriage motion is reversed, on subsequent sweep in direction Y, the airflow direction in airflow zones R and S reverse, as shown by the arrows in FIG. 5B . As fluid is ejected onto the receiving medium, residual droplets are created and trail the carriage in airflow zone S. The residual fluid mist droplets created on prior sweeps are forcibly expelled by the airflow in airflow zone R through opening 300 before they have a chance to settle on any of the internal structures or surfaces of the fluid ejector sweep path containment. [0058] FIGS. 6 A-B are schematic diagrams illustrating a second exemplary embodiment of the airflow pattern to support mist removal from the fluid ejector carriage sweep path containment 100 . Optional filters 600 are introduced in proximity to the openings 300 . As the fluid ejector carriage 200 translates along at least one structure (not shown) inside the fluid ejector carriage sweep path containment 100 in direction X, air is drawn in through opening 300 into the airflow zone R and is expelled through opening 300 from airflow zone S in the direction shown by the arrows in FIG. 6A . When carriage motion is reversed, on subsequent sweep in direction Y, the airflow direction in airflow zones R and S reverses, as shown by the arrows in FIG. 6B . The residual fluid mist droplets created are forcibly expelled in the fluid ejection process by the airflow motion on subsequent sweeps, through filter 600 and opening 300 before the mist droplets settle on any internal structure or surface of the fluid ejector sweep path containment. The addition of fluid mist filters 600 , while restricting airflow to some extent, has the advantage that on subsequent sweeps in directions X and Y the fluid mist droplets are generally captured and managed by the filters 600 rather than being freely or completely exhausted out through openings 300 . [0059] FIG. 7 illustrates a second exemplary embodiment of a fluid ejector carriage usable with various exemplary embodiments of the systems, methods and structures according to this invention. Openings 400 are added in the side faces 236 / 238 of the fluid ejector carriage 200 , and in any structures that may be added so that the silhouette of the carriage approximates the cross-sectional area of the inside of the fluid ejector carriage sweep path containment. These openings facilitate airflow movement through the fluid ejector carriage 200 , as will be described in detail below. In various exemplary embodiments of the systems, methods and structures according to this invention, the openings 400 are completely unobstructed holes in the sides of the carriage, or are in the form of vents with louvers, screen and/or other such structures added. The openings 400 may include filters usable to trap mist or other contaminants. The openings 400 are added to facilitate manipulation of a percentage of the resultant airflow, based on fluid ejector carriage motion, through the fluid ejector carriage 200 . [0060] FIG. 8 illustrates a bottom view of a second exemplary embodiment of a fluid ejector carriage 200 usable with various exemplary embodiments of the systems, methods and structures according to this invention. FIG. 9 illustrates a side view of a second exemplary embodiment of a fluid ejector carriage 200 in a fluid ejector carriage sweep path containment. As shown in FIGS. 8 and 9 , the fluid ejector carriage 200 is mounted on at least one structure along which the carriage translates such as, for example, a fluid ejector carriage guide rod 250 and between the front and back panels 130 / 140 of the fluid ejector carriage sweep path containment 100 (depicted in FIG. 1 ). [0061] In various exemplary embodiments of the systems, methods and structures according to this invention, at least one structure or device 275 usable to manipulate the resultant airflow that passes through the fluid ejector carriage 200 through the side openings 400 (depicted in FIG. 7 ) is added. The at least one structure and/or device 275 directs the resultant airflow, generated by fluid ejector carriage motion in direction A, across the heater elements of the fluid ejection module and heat sinks, if installed, to dissipate the heat generated by the fluid ejection operation. [0062] FIGS. 10 A-B are schematic diagrams illustrating a first exemplary embodiment of the airflow pattern to support fluid ejector element and/or heat sink cooling through the fluid ejector carriage 200 . As the fluid ejector carriage 200 translates along at least one structure (not shown) inside the fluid ejector carriage sweep path containment 100 in direction X air is drawn in through opening 300 into airflow zone R and expelled through opening 300 from airflow zone S in the direction shown by the arrows in FIG. 10A . A percentage of the air inside the fluid ejector carriage sweep path containment 100 passes through the fluid ejector carriage 200 in resultant direction V. This airflow is manipulated by one or more structures and/or devices 275 (depicted in FIG. 8 ) across the heater elements of the fluid ejector module and heat sinks, if installed, housed in the fluid ejector carriage 200 , to dissipate heat. When fluid ejector carriage motion is reversed on a subsequent sweep in direction Y, airflow direction in airflow zones R and S reverse, as shown by the arrows in FIG. 10B . Heated air that remained in airflow zone R based on the resultant airflow V from the previous sweep is then expelled from airflow zone R while resultant airflow W in FIG. 10B is directed through the fluid ejector carriage 200 to continue the cooling process. [0063] FIGS. 11 A-B are schematic diagrams illustrating a second exemplary embodiment of the airflow pattern to support fluid ejector element and/or heat sink cooling through the fluid ejector carriage 200 . As shown in FIG. 11A , optional louvers 700 are introduced. [0064] In the various exemplary embodiments of the systems, methods and structures according to this invention, the percentage of the resultant airflow generated by fluid ejector carriage 200 movement in the fluid ejector carriage sweep path containment 100 that is available for fluid ejector element and/or heat sink cooling is dependent on the size of the openings 400 in the side of the fluid ejector carriage 200 and constriction of exhaust air from the fluid ejector carriage sweep path containment 100 . Constriction of exhaust air can be accomplished by: decreasing the size of the openings 300 in the ends of the fluid ejector carriage sweep path containment 100 ; increasing the density of the filter elements 600 , depicted in FIG. 6 ; introducing one-way air vents and/or louvers 700 A and B; or, if airflow across the fluid ejector elements and/or heat sink is the only objective, doing away with the openings 300 altogether, resulting in substantially closed ends to the fluid ejector carriage sweep path containment 100 . [0065] In the exemplary embodiment of this invention depicted in FIGS. 11 A-B, as the fluid ejector carriage 200 translates along at least one structure (not shown) inside the fluid ejector carriage sweep path containment 100 in direction X, air is drawn in through the open louvers 700 , in proximity to opening 300 , into airflow zone R and exhausted from airflow zone S through louvers 700 . A portion of the resultant airflow generated by the fluid ejector carriage motion is forced through the opening in the fluid ejector carriage 200 in the direction depicted by the arrow V in FIG. 11A . When fluid ejector carriage motion is reversed, on a subsequent sweep in direction Y, the airflow patterns in airflow zones R and S stop when the louvers 700 close, as shown in FIG. 11B . Motion of the fluid ejector carriage 200 in direction Y causes air in airflow zone R in front of the fluid ejector carriage, restricted by the closed louvers, from being exhausted, to be reversed such that a larger percentage of the airflow is forced through the openings in the fluid ejector carriage 200 in the resultant direction W, as depicted in FIG. 11B . [0066] FIGS. 12 A-B are schematic diagrams illustrating a first exemplary embodiment of an airflow pattern to support drying and/or setting of the fluid ejected onto a receiving medium. In the various exemplary embodiments of the systems, methods and structures according to this invention, the fully closed carriage depicted in FIGS. 3 and 4 facilitates drying/setting of the fluid deposited on the receiving medium as a portion of the airflow in front of the carriage as it translates along at least one structure will be sheared across the face of the receiving medium based on the piston like effect of the carriage and the fact that the face of the fluid ejector sweep path containment adjacent to the receiving medium is essentially open such that the airflow generated by the carriage motion is not restricted by the structure of the face but rather by the presence of the receiving medium. As the fluid ejector carriage 200 translates along at least one structure (not shown) inside the fluid ejector carriage sweep path containment 100 in direction X, air is drawn in through opening 300 into airflow zone R. Based on constriction in the exit side opening, a portion of the resultant airflow V which meets the face of the fluid ejector carriage 200 is deflected generally in the direction of the receiving medium 500 as shown in FIG. 12A . When fluid ejector carriage 200 motion is reversed, on a subsequent sweep in direction Y, airflow direction in airflow zones R and S reverses, as shown in FIG. 12B , the process of fluid drying/setting continues with each subsequent sweep and the directing of a portion of the resultant airflow toward the receiving medium 500 . [0067] In the various exemplary embodiments of the systems, methods and structures according to this invention, enlarging the span-wise slot in the side of the fluid ejector sweep path containment that faces the receiving medium, specifically in the direction that the receiving medium translates, can further facilitate the process of drying/setting fluid deposited on the receiving medium. [0068] FIG. 13 illustrates a side view of a third exemplary embodiment of a fluid ejector carriage in a fluid ejector carriage sweep path containment usable with various exemplary embodiments of the systems, methods and structures according to this invention. As shown in FIG. 13 , the fluid ejector carriage 200 is surrounded by a bottom panel 110 , a front panel 130 , a back panel 140 , and a movable top panel 150 . The movable top panel 150 facilitates access to the fluid ejector carriage 200 , for example, when opened in direction C. Movable top panel 150 may be provided with any conventional or subsequently developed removable mounting structure, such as a hinge or a fully removable mount so as to provide access to the sweep path for maintenance, repair or other purpose. It should be appreciated that any of the panels or combinations of panels may be removably provided to facilitate access to the fluid ejector carriage 200 or sweep path. [0069] In the exemplary embodiment depicted in FIG. 13 , the fluid ejector carriage 200 includes a structural interface such as a fluid ejector carriage rod guide 225 to accommodate a structure upon which the fluid ejector carriage translates such as, for example, a fluid ejector carriage guide rod (not shown). The side panels 236 / 238 of the fluid ejector carriage 200 have a complex shape which substantially conforms to the internal cross-sectional shape of the fluid ejector carriage sweep path containment 100 comprising the fluid ejector carriage sweep path containment panels 110 / 130 / 140 / 150 . In the exemplary embodiment shown in FIG. 13 , the fluid ejector element 265 is mounted on the bottom face of the fluid ejector carriage 200 . The fluid ejector carriage sweep path containment 100 provides an opening 115 in the bottom panel 110 to facilitate access of the fluid ejector element 265 to the receiving medium 500 . [0070] In the exemplary embodiment depicted in FIG. 13 , the gap between the internal faces of the fluid ejector carriage sweep path containment panels 110 / 130 / 140 / 150 and the fluid ejector carriage 200 is generally minimized to facilitate as complete air flow movement on either side of, and to minimize leakage past, the fluid ejector carriage 200 as the fluid ejector carriage 200 translates along the at least one structure. It should be appreciated that the silhouette of the fluid ejector carriage 200 could embody any simple or complex shape or combination of shapes, and may include at least one protrusion or extension as a structure to facilitate alignment of the fluid ejector carriage 200 in the fluid ejector carriage sweep path containment 100 . [0071] FIG. 14 illustrates a fourth exemplary embodiment of a fluid ejector carriage usable with various exemplary embodiments of the systems, methods and structures according to this invention. As depicted in FIG. 14 , structures 910 and 920 are added to the sides of the fluid ejector carriage 200 . These structures 910 and 920 are manipulated, shaped and/or enlarged to fit the cross-sectional silhouette of the fluid ejector carriage sweep path containment. Such structures 910 and 920 include, but are not limited to, simple lightweight baffles specifically designed to mirror the cross-sectional shape and size of the inside of the fluid ejector carriage sweep path containment. For simplicity, clarity and ease of depiction, the structures 910 and 920 depicted in FIG. 14 are generally rectangular. It should be appreciated that these structures 910 and 920 can be of any simple or complex shape, and an appropriate size, as long as the essential characteristic of generally promoting maximum airflow manipulation within the fluid ejector sweep path containment is maintained. [0072] In the various exemplary embodiments of the systems, methods and structures according to this invention, at least one non-fluid ejection sweep of the fluid ejector carriage in the fluid ejector carriage sweep path containment may be added to the end of, or interleaved throughout, the fluid ejection process to facilitate: better mist removal and control; additional fluid ejection device cooling; and/or improved drying/setting of all lines or fields of fluid deposited on the receiving medium. [0073] While this invention has been described in conjunction with the exemplary embodiments outlined above, various alternatives, modifications, variations, and/or improvements, whether known or that are, or may be, presently unforeseen, may become apparent. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and/or scope of the invention. Therefore, the systems, methods, structures and/or devices according to this invention are intended to embrace all known, or later-developed alternatives, modifications, variations, and/or improvements.

A system, method and structure that promotes removing mist, dissipating heat, and/or drying a receiving medium in a fluid ejection device. This is achieved by substantially enclosing the sweep path of the fluid ejector carriage and manipulating the generally enclosed airflow that results from translating the fluid ejector carriage in a sweep direction.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority of U.S. provisional applications No. 60/330,689 filed on Oct. 29, 2001 and No. 60/333,753 filed on Nov. 29, 2001. FIELD OF THE INVENTION [0002] The present invention relates to a simulation system, a simulation method and a computer-readable medium for analysis, and synthesis of human motion under partial assist from powered augmentation devices. BACKGROUND OF THE INVENTION [0003] Effective usage of human assistive systems or augmentation devices for restoration or enhancement of motor function is an important area of research in rehabilitation and performance enhancement. A partial list of important and desired features of an effective assistive system include: (1) a decrease in energy rate and cost with respect to able-bodied subjects performing the same task, (2) minimum disruption and maximum comfort of normal activities when employing the assistive system, and (3) practicality. [0004] The third requirement considers the ease of wearing such a device and its power consumption needs. These requirements and available technology have led to the development of externally powered orthoses and prostheses that interface directly or indirectly with the human neuromuscular system. Although significant progress has been made in meeting many of the requirements needed for development of practical human assist devices (Popovic, D., Externally Powered and Controlled Orthotics and Prosthetics. The Biomedical Engineering Handbook, Editor Bronzino, J. D., 2nd ed. Vol. 2, Chapter 142, 2000), realization of such systems for daily applications is still in its infancy. The complexity of the central nervous system (CNS) control and the interface between voluntary control and external artificial control are still challenging, unanswered questions. [0005] At Honda's Wako Research Center, a mechanically powered walking assist prototype system was recently unveiled (Katoh and Hirata, The Concept of a Walking Assistance Suit, Welfare Engineering Symposium, The Japan Society of Mechanical Engineers, August 2001). The target application is to help the elderly and disabled people to either execute daily tasks they could not previously perform, or use less physical exertion than they currently employ for these tasks. The tasks considered include walking, lifting, sitting/standing, and climbing stairs. Two important and challenging questions to consider in the implementation of the Honda prototype and similar human augmentation systems include: 1) analysis and monitoring of biomechanical as well as physiological quantities which cannot be readily measured and 2) the synthesis of an active control which can safely and effectively augment voluntary control. By developing computational methods to study these issues, future performance of human augmentation devices can be studied through simulation, without constraints imposed by hardware implementations of current technology. Simulation studies also enable us to estimate physiological quantities that cannot be easily measured, including muscle forces, joint forces, and energetics of motion. We can simulate effects of aging, predict muscular activity, estimate muscle fatigue and capacity, and detect potential dangerous physiological conditions. It should be mentioned that the exclusive use of simulation is not a substitute for eventual testing on live human subjects. However, an accurate subject-specific simulation allows control algorithms to be designed and refined for the walking assist device. This is especially relevant in our target user population because they already have existing health constraints. [0006] U.S. Pat. No. 6,152,890 discloses a device and a method for the recording, presentation and automatic classification of biomechanical variables measured on a freely moving test person during a work shift. [0007] Japanese patent publication unexamined No. 2000-249570 discloses a method for generating human kinematic data. [0008] “Gruber, K. et. al., 1998. A comparative study of impact dynamics: wobbling mass model versus rigid body models. Journal of Biomechanics 31, 439-444” discloses inverse dynamics model used to simulate the human body. [0009] However, any of the above documents does not deal with analysis and synthesis of human motion under assist from powered augmentation devices. [0010] Accordingly, what is needed is a system and a method for analysis and synthesis of human motion under assist from powered augmentation devices. SUMMARY OF THE INVENTION [0011] According to one aspect of the invention, a simulation system is provided for a combined musculoskeletal and augmentation device system including segments and joints connecting the segments. The simulation system comprises a dynamics model of the combined musculoskeletal and augmentation device system and an augmentation device controller for control of the augmentation device. The simulation system further comprises an inverse dynamics model for the musculoskeletal and augmentation device system and a muscle force and muscle capacity module for checking and adjusting the computed torques. The dynamics model of the combined musculoskeletal and augmentation device system receives feasible computed torques at the joints as inputs and delivers simulated kinematic data of the segments as outputs. The augmentation device controller for control of the augmentation device, receives the simulated kinematic data as inputs and delivers assist torques as outputs. The inverse dynamics model for the musculoskeletal and augmentation device system, receives the simulated kinematic data, desired kinematic data of the segments and the assist torques as inputs and delivers the computed muscle torques and net joint torque as outputs. The muscle force and muscle capacity module for checking and adjusting the computed torques, receives the computed muscle torques as inputs and delivers feasible computed torques as outputs after making adjustments to the computed torques. [0012] According to another aspect of the invention, a method is provided for simulating a combined musculoskeletal and augmentation device system including segments and joints connecting the segments. The method comprises the steps of computing assist torques of the augmentation device, based on simulated kinematic data and computing torques based on the simulated kinematic data, desired kinematic data of the segments and the assist torques. The method further comprises the steps of checking and adjusting the computed torques and computing the simulated kinematic data of the segments based on the computed torques at the joints. [0013] According to another aspect of the invention, a computer readable medium containing a program for simulating a combined musculoskeletal and augmentation device system including segments and joints connecting the segments, is provided. The program comprises instructions of computing assist torques of the augmentation device, based on simulated kinematic data and of computing torques based on the simulated kinematic data, desired kinematic data of the segments, and the assist torques. The program further comprises instructions of checking and adjusting the computed torques and of computing the simulated kinematic data of the segments based on computed torques at the joints. [0014] According to an embodiment of the invention, muscle forces are deduced from the computed torques, compared with maximum force limits and adjusted if the muscle forces exceed limits, to obtain feasible torques. [0015] According to another embodiment of the invention, muscle forces with and without the assist torques are compared in order to asses whether the assist torque control helps or hinders motion and if the assist torque control hinders motion the muscle forces are adjusted and feasible joint torques are computed. [0016] According to another embodiment of the invention, muscle forces with and without the assist torques are compared in order to asses whether the assist torque control helps or hinders motion and if the assist torque control hinders motion the assist torque control law is adjusted to ensure that feasible joint torques are computed. [0017] According to another embodiment of the invention, muscle forces are deduced based on a static optimization criterion in which a sum of muscle activation squared is minimized. [0018] According to another embodiment of the invention, modified accelerations of kinematic data are obtained through non-linear position and velocity feedback from the simulated kinematic data. [0019] According to another embodiment of the invention, the kinematic data include position data, velocity data and acceleration data and estimates of kinematic data are computed, through non-linear feedback based on desired acceleration data, error between simulated position data and desired position data and error between simulated velocity data and desired velocity data. [0020] According to another embodiment of the invention, the kinematic data include position data, velocity data and acceleration data and estimates of kinematic data are computed, through non-linear feedback based on error between simulated position data and desired position data and/or error between simulated velocity data and desired velocity data. [0021] According to another embodiment of the invention, computed reaction forces under the segments contacting the ground are obtained based on the feasible computed torques and the simulated kinematic data. [0022] According to another embodiment of the invention, gravity compensation control algorithm is employed, in which the assist torques are obtained to reduce the computed muscle force by artificially compensating for the forces due to gravity. [0023] According to another embodiment of the invention, change in the computed torques, due to compensation for gravity is obtained, using coordinates of the center of the mass of the segments. [0024] According to another embodiment of the invention, the coordinates of the center of the mass of the segments, are obtained from measurements of joint angles and segment lengths. [0025] According to another embodiment of the invention, change in the computed torques, due to compensation for gravity, is obtained using measured reaction forces under the feet. [0026] According to another embodiment of the invention, the feedback gains are selected to produce the fastest possible non-oscillatory response. DESCRIPTION OF THE DRAWINGS [0027] [0027]FIG. 1 a biped system having five degrees of freedom in the sagittal plane with intermittent ground contact during double support, single support, and air-born phase; [0028] [0028]FIG. 2 is a system model description with intermittent contact of left and right feet with the ground; [0029] [0029]FIG. 3 is an inverse dynamics controller with position and velocity feedback for calculation of torques that when applied to a system model, will track and reproduce the desired kinematic data; [0030] [0030]FIG. 4 is a muscle force and muscle capacity module; [0031] [0031]FIG. 5 is a block-diagram of the integrated simulation system; [0032] [0032]FIG. 6 is a flowchart illustrating a simulation process according to an aspect of the present invention; [0033] [0033]FIG. 7 is a simulation of the joint angles during a squatting maneuver without employing the desired accelerations (a=0), in which nearly perfect tracking of desired kinematic trajectories is illustrated; [0034] [0034]FIG. 8 is a simulation of the joint torques during a squatting maneuver without employing the desired accelerations (a=0), in which the proposed method using nonlinear feedback (NLF) produces nearly identical joint torque estimates as compared to the ground truth (ideal) joint torques obtained by a noise free inverse dynamics computation; and [0035] [0035]FIG. 9 is a simulation of the horizontal and vertical ground reaction forces during a squatting maneuver without employing the desired accelerations (a=0), in which the proposed method using nonlinear feedback (NLF) produces nearly identical ground reaction estimates as compared to the ground truth (ideal) ground reaction forces obtained by an Iterative Newton Euler inverse dynamics procedure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0036] The present invention provides computational methods for analysis, and synthesis of human motion under partial assist from powered augmentation devices. The algorithms are integrated in a simulation platform to be used as a test-bed for prototyping, simulating, and verifying algorithms to control human motion under artificial control. The analysis and synthesis problems in human motion are formulated as a trajectory tracking control algorithm using inverse and forward models coupled by proportional and derivative feedback terms. A muscle force distribution and capacity module is used to monitor the computed joint torques in order to assess the physiological consequences of the artificial control, and if needed to make modifications. This framework allows us to verify robustness, stability, and performance of the controller, and to be able to quickly change parameters in a simulation environment. We can study many different motions in a simulation environment. Thus, future performance and designs of human augmentation devices can be studied through simulation, without the risk and constraints imposed by hardware implementations of current technology. [0037] The System Model [0038] The system (or plant) refers to a dynamic model of the combined musculoskeletal and augmentation device system. The system may be designed having various degrees of complexity, depending on the requirements imposed by the study. Without loss of generality, we consider a simple planar biped system to illustrate the concepts (See FIG. 1). The equations of motion are formulated in such a way to handle three phases of biped motion as shown in FIG. 1. They include single support, double support, and airborn. Let q be the coordinates corresponding to the rotational and translational degrees of freedom. q=[x 3 y 3 Θ 1 Θ 2 Θ 3 Θ 4 Θ 5 ] T   (1) [0039] where (x 3 , y 3 ) corresponds to the center of mass of the torso and the joint angles Θ are measured clockwise from the vertical. [0040] The system is actuated by voluntary control from the muscles and artificial control from the augmentation device. The total torque applied at the joints (net joint torque) are the combined torque from the muscles (τ m ) and the assist actuators (τ a ) τ=τ a +τ m   (2) [0041] Let C(q) represent the foot-floor contact constraints and Γ=[Γ L Γ R ] T be the vector corresponding to the ground reaction forces under the left and right feet. The equations of motion of the system are given by, J  ( q )  q ¨ + B  ( q , q . )  q . + G  ( q ) + T ad = ∂ C T ∂ q  Γ ′ + D     τ ( 3 ) [0042] where J, B, and G correspond to the inertia, coriolis and centrifugal torques, and gravitational terms, respectively. The vector T ad models the augmentation device dynamics and the constant matrix D characterizes the torque coupling effects at the joints. The matrix D is present because absolute coordinates for the joint angles are used in the formulation of the equation of motion, as opposed to relative coordinates. The ground reaction forces may be expressed as a function of the state and inputs by (Hemami, H., A feedback On-Off Model of Biped Dynamics. IEEE Transactions on Systems, Man, and Cybernetics, Vol. SMC-10, No. 7, July 1980). Γ =    ( ∂ C ∂ q  J  ( q ) - 1  ∂ C T ∂ q ) - 1  ( - ∂   ∂ q  ( ∂ C ∂ q  q . )  q . +    ∂ C ∂ q  J  ( q ) - 1  ( B  ( q , q . )  q . + G  ( q ) + T ad - D     τ ) ) ( 4 ) [0043] [0043]FIG. 2 shows a system model description with intermittent contact of left and right feet with the ground. Forward dynamic simulations are performed by computing the induced accelerations {umlaut over (q)} obtained from Equation 3 and Equation 4, using the simulated state variable q and {dot over (q)} which are obtained by numerical integration. [0044] The Internal (Inverse) Model [0045] It has been demonstrated that the behavior of the human body when coupled with a novel mechanical system is very similar to the behavior that results when the controller relies on an internal model. One such internal model is thought to be a forward model, a term used to describe the computations involved in predicting sensory consequences of a motor command. There are a number of studies that have suggested that a forward model may be used by the human central nervous system (CNS) to estimate sensory consequences of motor actions (Wolpert, D. M., Miall, R. C., Kerr, G. K., Stein, J. F. Ocular limit cycles induced by delayed retinal feedback. Exp Brain Res., 96: 173-180, 1993; Flanagan. J. R., Wing, A. M. The role of internal models in motion planning and control: evidence from grip force adjustment during movements of hand held loads. J. Neurosci, 17:1519-1528, 1997). This theory is easily understood when considering transmission delays inherent in the sensory-motor loop. Although a forward model is particularly relevant to feedback control of time delayed systems, an inverse model is sometimes considered to predict the motor commands that are appropriate for a desired behavior (Atkeson, C. G. Learning arm kinematics and dynamics. Annu Rev. Neurosci, 12:157-183, 1989; Kawato, M., Adaptation and learning in control of voluntary movement by the central nervous system. Advanced Robotics 3, 229-249, 1989; Shadmehr, R., Leaming virtual equilibrium trajectories for control of a robot arm. Neural Comput, 2:436-477, 1990; Gomi, H., Kawato, M., The cerebellum and vor/okr learning models. Trends Neurosci, 15:445-453, 1992). [0046] Inverse models are generally not considered for control of time delayed systems since the controller would seem to not have the ability to respond to the error and results in instability. However, it is plausible that local or intrinsic feedback mechanisms in conjunction with an inverse model can function to stabilize a system with latencies. Local feedback with stabilizing characteristics is believed to exist in humans in the form of viscoelastic properties of muscles and spinal reflex loop. The concept of an inverse model is also attractive for analysis problems of biomechanical quantities, whereby internal loads are estimated from kinesiological measurements. The approach adopted here in developing a computational model of human sensory motor control is based on the concept of an inverse model coupled with nonlinear feedback (FIG. 3). This mechanism is compelling from the standpoint of biomechanical analysis of human motion as well as the synthesis of artificial control. Let q d represent the desired kinematics, obtained from motion capture data. The following control law (Dτ′), when applied to the system equations, will result in a simulated response that will track and reproduce the desired kinematics data, D     τ ′ = J  ( q )  q ¨ * + B  ( q , q . )  q . + G  ( q ) + T ad - ∂ C T ∂ q  Γ ′ ( 5 ) [0047] where, {umlaut over (q)}*=a{umlaut over (q)} d +K p ( q d −q )+ K v ( {dot over (q)} d −{dot over (q)} )  (6) [0048] The diagonal matrices K p and K v represent the position and velocity feedback gains, respectively. The eigenvalues of the closed loop system are related to the feedback gains by the following, K p =−(λ 1 +λ 2 )  (7) K v λ 1 λ 2   (8) [0049] A critically damped response (fastest possible non-oscillatory response) to the tracking error can be achieved by specifying the eigenvalues to be equal, real, and negative. The parameter a is constant and set to 0 or 1, depending on the severity of noise in the measurements. If the desired trajectories are obtained from noisy motion capture measurements, it may be appropriate to set a=0 and to specify the eigenvalues to be large and negative. This way, tracking is achieved without the need to compute unreliable accelerations from noisy kinematics data. [0050] Muscle Force and Muscle Capacity [0051] The muscle force and muscle capacity module should ideally be implemented in the forward path of the closed loop system (as shown in FIG. 5). However, it may also be implemented as a separate module whose output is used for analysis purpose only. In the latter case, the module's inputs would tap into the required variables of the closed loop system, but the module would not alter the closed loop dynamics. [0052] In either case, a number of different muscle force distribution algorithms may be implemented. The underlying concepts of our choice of muscle force distribution algorithm is presented below. [0053] The relationship between the net muscular moment τ m and the muscle forces F m is given by, D     τ m = - ∂ L T ∂ q  F m ( 9 ) [0054] where L is the overall length of the muscle actuator, and ∂L T /∂q is an (n×m) muscle moment arm matrix. Since the number of muscles (m) exceeds the degrees of freedom (n), the computation of the muscle actuator's excitation inputs (and the resulting forces) from an inverse dynamics computation amounts to solving a problem that is inherently ill-posed. Static, nonlinear optimization has been used extensively to predict the individual muscle forces to produce the required torque. There are several compelling reasons for using static optimization to predict the individual muscle forces: first, static, non-linear optimization techniques have well developed theoretical foundations. With the advance of commercial software for solving general, constrained, multi-variable non-linear optimization problems, it is now possible to solve sophisticated problems numerically in relatively short time. Second, the notion that muscle forces are controlled in some way to optimize physiological criteria has great intuitive appeal. It has been shown that for motions like walking, static optimization yields very similar results to dynamic optimization (Anderson, F C and Pandy, M G., Static and Dynamic Optimization Solutions for Gait are practically equivalent, Journal of Biomechanics 34, 2001, 153-161, 2001). [0055] A muscle force and muscle capacity module takes the computed torques from the inverse model (denoted by Dτ′) as inputs and calculates the muscle forces based on a static optimization criterion (module 410 in FIG. 4). While any cost function can be defined in solving the optimization problem, the one used here minimizes the sum of muscle activations squared J = ∑ i = 1 m  a i 2 ( 10 ) [0056] where m is the number of muscles crossing the joint, a i is the activation level for muscle i and is constrained to be between 0.01 and 1.0. A muscle force F i for muscle i can be represented as below; F i = a i  F i 0 ( 11 ) [0057] where F i 0 [0058] represents a maximum force limit for muscle i. A gradient based technique can be used to numerically solve for the muscle activations that minimize the cost function J while satisfying the joint moment equilibrium for all degrees of freedom of interest. The optimization problem can be solved using constrained nonlinear optimization (Sequential Quadratic Programming; AEM Design). Once the muscle activations are obtained, the muscle force can then be determined using the force-length-velocity-activation relationship of muscle (Zajac, F. E. Muscle and tendon: Properties, models, scaling, and application to biomechanics and motor control. Critical Reviews in Biomedical Engineering, 17(4):359-41 1, 1989; Anderson, F C and Pandy, M G., Static and Dynamic Optimization Solutions for Gait are practically equivalent, Journal of Biomechanics 34, 2001, 153-161, 2001 ; Hungspreugs, P., Thelen, D., Dariush, B., Ng-Thow-Hing, V., Muscle Force Distribution Estimation Using Static Optimization Techniques. Technical Report-Honda R&D Americas, April 2001). [0059] The computed muscle forces are then compared with physiological capacity of the muscle in the muscle capacity module 420 . The maximum force limits can be ascertained from the well-studied force-length-velocity relationship of muscle (Zajac 1989, cited above). In addition, the muscle forces with and without the assist torque are compared in order to assess whether the assist torque control has helped (improved efficiency) or hindered the motion. If the assist torque control hinders motion, the muscle forces are adjusted and feasible joint torques are computed (modules 430 and 440 in FIG. 4). A poorly designed assist control would then result in Dτ′≠Dτ, producing a simulated response that would not track the desired response. If the assist torques are well designed, Dτ′=Dτ and the resulting motion would track the desired motion. [0060] Augmentation Device Controller [0061] The inputs to the human augmentation device may include the sensed state variables q s and/or {dot over (q)} s , which can be directly measured or estimated. These inputs, denoted by (q s , {dot over (q)} s ) represent a subset of the total number of state variables (q, {dot over (q)}) in our human model. In addition to the sensed state variables, measurements may also be used as input to the augmentation device controller. The augmentation device controller output represents the assist torque τ a , which is then input to the inverse model. [0062] Different control strategies may be used by the human augmentation device controller. For example, gravity compensation control can be used for tasks requiring an increase in potential energy of the total system (human and exoskeleton). Such tasks would include lifting objects, carrying loads, climbing stairs, rising from a chair, etc. A different control strategy, or hybrid control strategies, may be suitable for other tasks such as walking or running. Here, we will present the gravity compensation control algorithm. [0063] By using the Lagrangian, we can assess the total potential energy of the musculoskeletal system. Let U denote the total potential energy stored in the system, U = ∑ i - 1 n  m j  g T  X 1 ( 12 ) [0064] The torque at joint i due to gravity can be computed by taking the partial derivative of U with respect to q i , D     τ gr = ∂ U ∂ q i = ∑ j = 1 n  m j  g T  ∂ X j ∂ q i ( 13 ) [0065] where g T represents the gravitational acceleration vector, and X j represents the coordinates of the center of mass of segment j. Suppose the knee joint between segment 1 and segment 2 is actuated by an augmentation device and the angle corresponding to q 2 (represents q s ⊂q) is measurable. The following control law may be used as one algorithm for the augmentation device controller D     τ a = D     τ g     r = ∂ U ∂ q 2 = ∑ j = 1 n  m j  g T  ∂ X j ∂ q 2 ( 4 ) [0066] Note that the above control algorithm requires the center of mass positions of all the link segments (denoted by X j ). Although X j can be derived from measurement of joint angles and segment lengths, it may not be feasible to measure all joint angles and all segment lengths. Alternatively, if the vertical component of the ground reaction force under each foot can be measured or estimated, it is possible to derive an iterative “ground up” gravity compensation algorithm which would eliminate the need for access to center of mass of every segment. [0067] Integration of Modules [0068] The block-diagram of the integrated modules as has been presented in the description is shown in FIG. 5. The Augmentation device controller is presumed to have as inputs the sensed states and output the assist torques. The overall framework is very general and enables flexible design of the augmentation device control signals. The details of such designs are easily made by those skilled in the art. [0069] [0069]FIG. 6 shows a flowchart illustrating a simulation process according to an embodiment of the present invention. At step S 605 , time t is set to 0. At step S 610 , desired kinematic data for the combined musculoskeletal and augmentation device system are obtained. The desired kinematic data may be obtained from motion capture data. [0070] At step S 612 , the simulated kinematic data is fed back to obtain tracking error. [0071] At step S 615 , modified accelerations {umlaut over (q)}* are computed using Equation 6. [0072] At step 617 , the sensed kinematic data is fed back. [0073] At step S 620 , assist torques Dτ a are computed using the augmentation device controller 500 . [0074] At step S 625 , torques Dτ′ are computed using Equation 5 (inverse model 300 ). [0075] At step S 630 , muscle forces are checked and adjusted to modify the corresponding torques (muscle force and capacity module 400 ). [0076] At step S 635 , the induced accelerations {umlaut over (q)} are computed using Equations 3 and 4 and the simulated kinematic data q and {dot over (q)} are obtained by numerical integration (modules 200 , 210 and 220 ). [0077] At step S 640 , time t is incremented and at step S 645 , whether t is less than t c or not is determined. If t is less than t c , the process returns to step S 610 . If t is equal to or greater than t c , the process ends. [0078] It should be noted that the above-mentioned equations, modules or functions can be implemented in any kind of computing devices, including general-purpose computers such as personal computers, work stations and main frame computers, and ASICs (Application Specific Integrated Circuits). [0079] In an embodiment a general-purpose computer is employed to implement the invention. The general-purpose computer comprises software representing the above-mentioned equations, modules or functions. The software is preferably contained in computer readable mediums. Computer readable mediums include read only memories, random access memories, hard disks, flexible disks, compact disks and so on. [0080] Simulations [0081] A very simple simulation of the tracking system is carried out to illustrate some of the concepts proposed in the description. [0082] A simulation illustrating the tracking characteristics of the proposed method without acceleration estimates of the reference trajectory, is provided. In particular, the double support phase of the biped system during a squatting maneuver was simulated. The results are illustrated in FIGS. 7 to 9 . [0083] In FIG. 7, the desired and simulated joint trajectories illustrate the effectiveness of the tracking procedure. These results were obtained by setting a=0, i.e. no acceleration estimates were used as inputs to the inverse model. The corresponding joint torques and ground reaction forces are depicted in FIG. 8 and FIG. 9, respectively. [0084] It should be noted that those skilled in the art can modify or change the above-mentioned embodiments, without departing from the scope and spirit of the present invention. It should therefore be noted that the disclosed embodiments are not intended to limit the scope of the invention, but only to exemplarily illustrate the invention.

A system, a method and a computer readable medium are provided for simulating a combined musculoskeletal and augmentation device system. The dynamics model of the combined musculoskeletal and augmentation device system receives computed torques at the joints as inputs and delivers simulated kinematic data of the segments as outputs. The augmentation device controller for control of the augmentation device, receives the simulated kinematic data as inputs and delivers assist torques as outputs. The inverse dynamics model for the musculoskeletal and augmentation device system, receives the simulated kinematic data, desired kinematic data of the segments and the assit torques as inputs and delivers the computed net joint torque and muscle torque. The muscle force and muscle capacity module for checking and adjusting the computed torques, receives the computed torques as inputs and delivers computed torques as outputs after the checking and adjustment.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the priority benefit of China application serial no. 201110100828.0, filed on Apr. 21, 2011. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a DC to DC buck converting controller, and more particularly a DC to DC buck converting controller with programmable output voltage. [0004] 2. Description of Related Art [0005] FIG. 1 is a schematic diagram of a conventional DC to DC buck converting circuit. The DC to DC buck converting circuit comprises a controller 10 , two switches M 1 and M 2 , an inductance L, a capacitance C, a bootstrap circuit BS and a voltage divider VD. The voltage divider VD detects an output voltage of the buck converting circuit and accordingly generates a feedback signal FB. The controller 10 turns the switches M 1 and M 2 on/off according to the feedback signal FB, so as to make the DC to DC buck converting circuit to convert an input signal Vin into an output voltage Vout which is stabilized at a preset output voltage. [0006] The controller 10 comprises a comparator 12 , a constant on-time period circuit 14 , a logic control circuit 16 and two gate driving units 18 , 20 . The comparator 12 generates a feedback control signal according to the feedback signal FB and a reference voltage Vref. An on-time period of the constant on-time period circuit 14 is determined by the input voltage Vin and the output voltage Vout, and the constant on-time period circuit 14 generates an constant on-time signal according to the feedback control signal. The logic control circuit 16 determines conduction timing and cut-off timing of the switches M 1 and M 2 , and makes the switches M 1 and M 2 turned on and off separately via the gate driving units 18 and 20 . The switch M 2 is a N-type MOSFET. For avoiding that the gate driving unit 20 in the controller 10 cannot generate a signal which is high enough to turn on the switch M 2 . The bootstrap circuit BS is used supply a sufficiently high voltage to the gate driving unit 20 . [0007] The constant on-time period circuit 14 adjusts the constant on-time period according to the input voltage Vin and the output voltage Vout to make the DC to DC buck converting circuit operate in a quasi-constant frequency. Therefore, an electromagnetic interference (EMI) generated by the switches M 1 and M 2 can be easily filtered out, regardless of the levels of the input voltage Vin and the output voltage Vout. [0008] However, the DC to DC buck converting circuit must economize on energy to meet the current energy-saving trend, which means that the DC to DC buck converting circuit needs energy-saving mode to adjust output voltage. Therefore, it is an important issue to support the energy-saving mode on the DC to DC buck converting circuit. SUMMARY OF THE INVENTION [0009] The invention uses an extra setting signal to set the level of the output voltage to achieve the function of energy-saving mode for adjusting the output voltage. [0010] To accomplish the aforementioned and other objects, an exemplary embodiment of the invention provides a DC to DC buck converting controller, adapted to control a DC to DC buck converting circuit which converts an input voltage into an output voltage. The DC to DC buck converting controller comprises a feedback circuit and a driving circuit. The feedback circuit generates a feedback control signal according to a reference voltage and a feedback signal representative of the output voltage. The driving circuit generates at least one control signal to control the DC to DC buck converting circuit according to the feedback control signal. The driving circuit comprises a constant on-time period unit. The constant on-time period unit sets a constant on-time period to make the driving circuit to determine a duty cycle of the DC to DC buck converting circuit according to the level of the reference voltage. Wherein, the level of the reference voltage is determined by a preset output voltage. [0011] It needs to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. In order to make the features and the advantages of the invention comprehensible, exemplary embodiments accompanied with figures are described in detail below. BRIEF DESCRIPTION OF THE DRAWINGS [0012] The present invention will now be specified with reference to its preferred embodiment illustrated in the drawings, in which: [0013] FIG. 1 is a schematic diagram of a conventional DC to DC buck converting circuit; [0014] FIG. 2 is a schematic diagram of a DC to DC buck converting circuit according to a first embodiment of the invention; and [0015] FIG. 3 is a schematic diagram of a constant on-time period circuit according to an example shown in the FIG. 2 . DESCRIPTION OF EMBODIMENTS [0016] In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawings. [0017] FIG. 2 is a schematic diagram of a DC to DC buck converting circuit according to a first embodiment of the invention. The DC to DC buck converting circuit comprises a controller 100 , two switches M 1 and M 2 , an inductance L, a capacitance C, a bootstrap circuit BS and a voltage divider VD. The voltage divider VD detects an output voltage Vout of the DC to DC buck converting circuit and accordingly generates a feedback signal FB. The controller 100 turns the switches M 1 and M 2 on/off according to the feedback signal FB, so as to make the DC to DC buck converting circuit convert an input voltage Vin into an output voltage Vout which is stabilized at a preset output voltage. [0018] The controller 100 comprises a feedback circuit 112 , a driving circuit which comprises a constant on-time period circuit 114 , a logic control circuit 116 and two gate driving units 118 , 120 . The feedback circuit 112 comprises a comparator. An inverting input terminal of the comparator receives the feedback signal FB and a non-inverting input terminal thereof receives a reference voltage Vr and accordingly outputs a feedback control signal Sfb. The constant on-time period circuit 114 receives the feedback control signal Sfb and the reference voltage Vr and accordingly generates a constant on-time signal Sto. A pulse width (time period) of the constant on-time signal Sto is determined by a level of the reference voltage Vr. A starting timing of the constant on-time signal Sto, i.e., rising/falling edge, is determined according to the feedback control signal Sfb. The logic control circuit 116 is coupled with a connection node of the two switches M 1 and M 2 to detect a current of the inductance L and determine turned-on timings and turned-off timings of the two switches M 1 and M 2 according to the feedback control signal Sfb and the current of the inductance L. The logic control circuit 116 turns the two switches M 1 and M 2 on/off via the gate driving units 118 and 120 respectively. In the present embodiment, a duty cycle of the DC to DC buck converting circuit, i.e., a time ratio of a period time to transmit the power from the input voltage Vin into the DC to DC buck converting circuit via the switch M 1 and a cycle time thereof, is determined by turned-on period of the switch M 1 . That is, when a beginning of each cycle (when the level of the feedback signal FB is lower than the level of the reference voltage Vr), the feedback circuit 112 generates a feedback control signal Sfb to make the constant on-time period circuit 114 to generate the constant on-time signal Sto with a constant pulse width (time period). The logic control circuit 116 turns on the switch M 1 according to the constant on-time signal Sto. After the constant pulse width (time period), the logic control circuit 116 turns the switch M 1 off and turns the switch M 2 on to make the current of the inductance L freewheel through the switch M 2 . When the current of the inductance L is decreased to zero, the switch M 2 is turned off. [0019] The reference voltage Vr may be an external control signal, which a level of the reference voltage Vr is determined by an external circuit or set by users according to a preset output voltage. In the present embodiment, the controller 100 further comprises a reference voltage generating circuit 115 . The reference voltage generating circuit 115 generates a reference base voltage Vr 0 . The user makes the reference base voltage Vr 0 divided into a demand reference voltage Vr by a voltage divider and transmits the reference voltage Vr into the feedback circuit 112 and the constant on-time period circuit 114 . The voltage divider comprises the resistances RV 1 , RV 2 and a voltage division ratio thereof is set by the input voltage Vin and the preset output voltage. In addition, the voltage division ratio of the voltage divider VD may affect the ratio of the feedback signal FB and the output voltage Vout. Therefore, the ratio of the resistances RV 1 , RV 2 is set according to the voltage division ratio of the voltage divider VD. [0020] FIG. 3 is a schematic diagram of a constant on-time period circuit according to a second embodiment of the invention. The constant on-time period circuit 114 comprises a current source I, a period capacitance Cton and a comparator 1141 . The current of the current source I is set by a current mirror MI and an on-time period resistance Rton. The on-time period resistance Rton is coupled with the input voltage [0021] Vin and so a current flowing through the on-time period resistance depends on the the input voltage Vin. The current flowing through the on-time period resistance is mirrored to the current source I by the current mirror MI. On the beginning of each cycle, the period capacitance Cton is charging from zero by the current source I. The comparator 1141 compares the voltage of the period capacitance Cton with one of the original voltage Vset and the reference voltage Vr to generate the constant on-time signal Sto, and the original voltage Vset is higher than the reference voltage Vr. On the beginning of enabling the circuit, the comparator 1141 compares the voltage of the period capacitance Cton with the original voltage Vset to make the on-time period longer and so the output voltage Vout could be increased faster. Just before or when the output voltage Vout reaches the preset voltage, the comparator 1141 compares the voltage of the period capacitance Cton with the reference voltage Vr to make the output voltage Vout to be stabilized on the preset output voltage. The constant on-time period circuit 114 further comprises a SR flip-flop 1142 and an inverter 1143 . A set terminal S of the SR flip-flop 1142 is coupled with the output terminal of the comparator 1141 through the inverter 1143 , a reset terminal R thereof is coupled with the feedback circuit 112 and an output terminal is coupled with the discharging unit SWd. The discharging unit SWd is coupled with two ends of the period capacitance Cton to discharge the period capacitance Cton according to the controlling of the SR flip-flop 1142 . When the voltage of the period capacitance Cton is higher than the reference voltage Vr, the constant on-time signal Sto is changed into low level to trigger the SR flip-flop 1142 through the inverter 1143 . Then, the discharging unit SWd discharges the period capacitance Cton. When the output voltage Vout is lower than the preset voltage, the feedback control signal Sfb is at high level to make the SR flip-flop 1142 reset to stop the discharging unit SWD discharging. Therefore, on the beginning of each cycle, the output voltage Vout is lower than the preset output voltage and the period capacitance Cton is charged by the current sources I. When the voltage of period capacitance C is higher than the reference voltage Vr, the period capacitance Cton is discharged to zero voltage to wait for the next cycle. [0022] All the features disclosed in this specification (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

A constant on-time period of a DC to DC buck converting controller is adjusted according to a level of a preset output voltage. Therefore, the DC to DC buck converting controller of the present invention is suitable for any applications with different requests of output voltages or different operating mode.

FIELD OF INVENTION [0001] The present invention relates to pharmaceutical formulations for topical application and manufacturing processes therefor, which are suitable for the treatment of various topical infections. BACKGROUND OF THE INVENTION [0002] Anaerobic bacteria are frequently found in infections of the skin, soft tissue, bones and in bacteremia. Injury to skin, bone or soft tissue by trauma, ischemia or surgery creates a suitable environment for anaerobic infections. Since the sites that are colonized by anaerobic bacteria contain many species of bacteria, disruption of anatomic barriers allows penetration of many organisms, resulting in mixed infections involving multiple species of anaerobes combined with facultative or microaerophilic organisms. [0003] Two-thirds of clinically significant anaerobic infections involve following five anaerobes: Bacteroides fragilis group, Bacteroides melaninogenicus groups, Fusobacterium nucleatum, Clostridium perfringens , and anaerobic cocci. [0004] Certain types of infections as stated below in Table 1 commonly involve anaerobic bacteria including lower extremity infections in diabetics or in patients with severe peripheral vascular disease. TABLE 1 Skin and soft Incidence of anaerobic tissue infections involvement (%) Diabetic foot ulcers 95 Infected diabetic gangrene 85 Non-clostridial crepitant cellulitis 75 Decubitus ulcer with bacteremia 63 Cutaneous abscesses 62 Soft tissue abscesses 60 Topical infection of head and neck 48 Topical infection of trunk 36 Topical infection of hand 31 Topical infection of buttock 33 [0005] Therefore, there are many conditions such as diabetic ulcers, decubitus ulcers, cellulitis, pyoderma etc. that have aerobic and anaerobic microflora. Thus, it is rational to use an agent having action on both types of organisms. [0006] U.S. Pat. No. 4,803,066 describes antibacterial and antifungal composition for topical application the composition comprise azole derivative with silver compound. Metronidazole 1% solution is reported to be effective in treating various ulcers which included pressure sores in elderly and chronically ill patients, diabetic ulcers, venous ulcers. The solution was also used as irrigation or packs in the management of ischiorectal abscess, large abscesses in other areas, undermining subcutaneous cavitation complicating simple sacral pressure sores. Metronidazole topical therapy is also recommended for anaerobic decubitus ulcers (Grade III & IV), marginal cellulitis and sacral ulcers. [0007] U.S. Pat. No. 5,407,670 describes topical ointment for the treatment of epidermal trauma such as burns, rashes, lesions, wounds and decubital ulcers, which contains povidone-iodine along with polymyxin, bacitracin, neomycin, and sugar. U.S. Pat. No. 5,137,718 describes infection fighting composition for topical application containing povidone-iodine complex for viricidal or microbial agent. [0008] Patients admitted in ICU, trauma ward, emergency wards, burn wards, unconscious patients, patients with neurological/spinal disorders and patients undergoing urinary tract surgery are often catheterized. Bladder irrigation with Povidone-Iodine is effective in prevention of urinary tract infection after single or intermittent catheterization.[Van Den Broek P J, Lancet, March, 1(8428), 5635, 1985]. [0009] Metronidazole is a bactericidal. It has activity against the facultative anaerobes Gardnerella vaginalis and Helicobacter pyroli and is effective against some spirochetes. Moreover, several protozoa and anaerobic bacteria including Bacteroides and Clostridium Spp. are sensitive to Metronidazole. Efficacy of metronidazole against obligate anaerobic bacteria in vitro including the gram-negative organisms Bacteroides fragilis , Fusobacterium Spp., Peptococcus Spp., Peptostreptococcus Spp., and Villanelle Spp. is well established. [0010] The mechanism of action of Metronidazole is thought to involve interference with DNA by a metabolite in which a nitro group of metronidazole has been reduced by bacterial nitroreductases to an unstable intermediate, which interacts with DNA, effectively preventing further replication. [0011] A Variety of nitroimidazoles are widely used as anti bacterial, antitrichomonal, anti-parasitic agents. Representative active agents are tinidazole, nimorazole, panidazole, flunidazole, ronidazole but metronidazole is the only one which is widely accepted in therapy. [0012] Metronidazole is considered the ‘gold standard’ against which other antimicrobials with perceived anti-anaerobic activity are compared. This is due primarily to its killing of Baceroides spp., and the very low rate of resistance acquired by these bacteria.(Olsson-Liljequist B, Nord C E, Scand. J. Infect. Dis., 1981: Suppl. 26: 24-5, Aldridge K E, Gelfand M, Relier L B, et al; Aldridge K E, Gelfand M, Relier L B, et al; Diagn. Microbiol. Infect. Dis.; 1994; 18:235-41; Selkon J B, Scand. J. Infect. Dis., 1981: Suppl. 26: 19-23; Sigeti J S, Guiney Jr D G, Davis C E, J. Infect. Dis., 1983; 148:1083-9; Scher K. S., Surg. Gyn. Obstet., 1988: 167:175-9) [0013] The cure rates in patients with intra abdominal infections such as Gangrenous or perforated appendicitis improvement occurred in 100% of the patients. (Willis A. T., Ferguson I. R., et al., B. Med. J., 1976: 1: 318-21; Foster M. C., Kaplia L et al., Rev. Infect. Dis., 1986: 8 Suppl.5: 5634-8.) [0014] Metronidazole is much more in therapeutic use compared to other nitormidazoles. Metronidazole was marketed for therapeutic use in February 1960. [0015] Metronidazole is the only nitroimidazole available for topical treatment. Metronidazole 0.8% gel is used for treatment of malodeorous fungating tumors, Decebitus ulcers and varicose ulcers. Metronidazole 0.75% cream is employed for treatment of rosacea. [0016] Iodine has long been accepted as a uniquely effective antiseptic and used widely both for the prevention and treatment of infection. It has a broad antimicrobial spectrum: bacteria, viruses, bacterial endospores, fungi, and protozoas are destroyed, however, been limited by a number of undesirable factors. The disadvantages of iodine are an unpleasant odor and staining properties, unstability and irritation potential of solutions to animal tissue. Iodine solutions may prove toxic to open wounds. [0017] An iodophor which is a complex of iodine in ionic or molecular form or both with a carrier that serves to increase the solubility of iodine in water and also provides a reservoir of iodine for a controlled and sustained release over time. There are two categories of iodophors, water-soluble and water insoluble. An example of a water-soluble iodophor is the polyvinylpyrrolidone-iodine complex widely used as a germicidal solution. An example of a water insoluble iodophor is polyvinyl alcohol sponge complexed with iodine, which can be used to wipe down and disinfect hard surfaces. [0018] It was discovered that Povidone-Iodine [iodine complexed with the inert polymer, polyvinylpyrrolidone (povidone)] ceases to irritate, sensitize or stain and yet retains its unique microbicidal activity as iodine is continually delivered. Biochemical research has indicated that this high degree of microbiocidal activity is the result of the interruption of vital metabolic pathways. This is accomplished by the iodination of the amino acid sequence of the microorganisms' proteins. [Bloomfield S. F., “Chlorine & Iodine Formulations”, in Handbook of Disinfectants & Antiseptics, Ed. By Ascezi J. M., Marcel Dekker Inc., NY, 1996, pp 147-149] [0019] Povidone-Iodine is effective against variety of strains such as Staphylococcus aureus, Proteus mirabilus, Proteus vulgaris, Escherichia coli, Enterobacter areogenes , Enterobacter Spp., Streptococcus faecalis, Streptococcus pyogenes, Streptococcus hemolyticus, Salmonella typhimurium, Salmonella typhosa , Salmonella type C1, Salmonella Spp., Serratia marcescens , Serratia Spp., Shigella sonni, Pseudomonas aeruginosa, Klebsiella pneumoniae, Diplococcus pneumoniae, Mycobacterium tuberculosis, Bacillus subtillis, Clostridium septicum, Clostridium tetani, Bacillus subtillis spores, Trichophyton rubrum, Candida albicans, richomonas vaginalis, Aspergillus flavus, Aspergillus niger. [0020] Povidone-iodine is used for the treatment of burns and of different skin lesions (decubitus and leg ulcers, etc.). In special preparations it is available for the therapy of inflammations in the mouth and pharynx and for vaginitis. Povidone-Iodine is used in the treatment of skin disinfection in the prevention of nosocomial infections, especially, prior to invasive procedures such as the insertion of peripheral catheters, treatment of exit site infection [Tanaka S., Advances in Peritoneal Dialysis, 12, 214-7, 1996] and bacteraemia in haemodyletic patients [Fong I. W., Postgraduate Medicinal Journal, 69, Suppl 3S15-7, 1993]. It is also used as surgical scrub as an effective method for avoiding intra as well as post-surgical infection. [Tucci V. J., Stone A. M., Thompson C., Isenberg H. D., Wise L, Surg. Gynecol. Obstet., 145(3), 415-6,1977] Povidone-iodine cream effectively limits bacterial infection in patients with traumatic lacerations requiring sutures. [Gravett et al, Annals of Emergency Medicine, 16(2), 167-71, 1987]. [0021] Water soluble iodophors forms micellar aggregates which enables a reduction in the concentration of free available iodine in water as well as simultaneous reduction in the disadvantages of iodine i.e. its unpleasant odor, irritation and staining of tissue, and corrosion of metal surfaces. An important factor in creating an iodophor is that one wishes to keep the concentration of free iodine in the solution as low as possible; to be effective SUMMARY OF THE INVENTION [0022] Thus, taking into consideration the limitations associated with the conventional topical composition with individual active agents stated above, the present inventor has discovered a composition comprising of an iodophor and a alkyl imidazole, which has a wide antimicrobial activity against aerobic as well as anaerobic bacteria. Preferably, the composition comprises metronidazole and povidone-iodine. Povidone-Iodine acts against aerobic organisms and metronidazole acts against anaerobic organisms. [0023] The present invention provides formulations and methods for the treatment of individuals affected with various skin infections and injuries, such as pre-operative and post-operative antisepsis, diabetic ulcers, lapromatous ulcers, decubitus ulcers, cellulitis, and other skin infection showing the presence of both aerobic and anaerobic microorganisms, as well as wounds, such as contaminated lacerations, accidental wounds, traumatic wounds, abrasions, thermal wounds (Burns of 1st, 2nd, 3rd degree), and animal and human bites. The present invention also provides formulations and methods for the treatment of mycotic infections such as pyoderma, otitis externa, tinea pedis, tinea cruris, tinea corporis, tinea versicolor, and cutaneous candidiasis, topical treatment of monialliasis, trichomoniasis, and non-specific vaginitis. Moreover, the present invention provides formulations and methods for prophylactic treatment of patients, such as bladder irrigation during catheterisation and before catheter removal, and as a disinfectant in small surgical procedures, and in catheter (peritoneal/dialysis) exit site wounds. [0024] None of the references mentioned earlier in the text teach the combination of metronidazole and povidone-iodine for treatment of microbial and mycotic infections caused by aerobic as well as anaerobic microorganisms. It is a object of this invention to provide a pharmaceutical formulation comprising combination of metronidazole and Povidone-Iodine in the form of topical pharmaceutical composition having the effect on aerobic and anaerobic bacteria. This combination has been found to be therapeutically advanced over either metronidazole or Povidone-Iodine individually with improved patient compliance. [0025] The combination offers following advantages: [0026] Easy application schedule i.e. single application takes care of both the types i.e. aerobic and anaerobic organisms. [0027] Reduced number of applications. [0028] Broad spectrum of anti microbial activity [0029] Rapid control of infection. [0030] This formulation when applied on the affected part, flows and fills out the wounded area after application and thereafter comes into contact with the damaged tissue with microbial infection. Metronidazole exerts its aerobicidal activity and Povidone-Iodine reacts with amino acids of microbial cell wall of anaerobic bacteria present thereby killing the microbes. Thus, the combination comprising Metronidazole and Povidone-Iodine is therapeutically better over either metronidazole or Povidone-Iodine individually. The combination has a topical microbicidal activity against bacteria including spores, fungi, yeast, protozoa and viruses, even in presence of blood, serum, pus and necrotic tissue. DETAILED DESCRIPTION OF THE INVENTION [0031] The present invention is a pharmaceutical composition for topical application comprising of an iodophor and a alkyl imidazole, which has a wide antimicrobial activity against aerobic as well as anaerobic bacteria. Preferably, the composition comprises metronidazole and povidone-iodine. Povidone-Iodine acts against aerobic organisms and metronidazole acts against anaerobic organisms. [0032] The term “pharmaceutical composition for topical application”, as used herein, means various compatible dosage forms which are suitable for administration to a human or veterinary application. [0033] Suitably, the compositions is adapted for topical administration which include for instance, ointments, solutions, creams or lotions, powder, topical patches, aerosols and can be used in the form of scrub, irrigating solution and paint. In addition, compositions of the present invention may be used in impregnated dressings. Compositions of the present invention may also contain appropriate conventional additives such as preservatives, chelating agents, solvents to assist drug penetration and emollients, hydrocarbon waxes, oleaginous substances, fatty acids and fatty alcohol in ointments and creams. Ingredients present in the topical carrier of the present invention are suitable for administration to different infected sites. [0034] Such a preparation is most preferably administered in the form of ointment and solution although the other dosage forms are also advantageously envisioned. Advantages to administering the composition as a ointment and solution include convenience, ease of application, increased safety. [0035] Preferred pharmaceutical compositions for topical application according to the present invention comprises of metronidazole or a pharmaceutically acceptable salt or ester thereof from 0.01 to 10%, preferably from 0.05 to 5% and most preferably 1% by weight of the composition. [0036] Metronidazole, i.e., 1-(beta-hydroxyethyl)-2-methyl-5-nitroimidazole, belongs to the class of alkyl imidazole derivatives and are useful as antimicrobial agents. The term “metronidazole,” as used in this specification and claims, includes not only 1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole, but also those analogs and derivatives of metronidazole (salts, esters etc) that are soluble in the pharmaceutical compositions described herein and which exhibit therapeutic activity when applied as taught by the present invention. [0037] A preferred pharmaceutical compositions for topical application according to the present invention comprises of Povidone-Iodine from 1 to 20%, preferably from 3 to 10% and most preferably 5% by weight of the composition. [0038] Specific examples of iodophors useful in this invention include polyvinylpyrrolidone-iodine, polyvinyl alcohol-iodine, polyvinyl oxazolidone-iodine, polyvinyl imidazole-iodine, polyvinyl morpholone-iodine, polyvinyl caprolactam-iodine, soluble starch-iodine, betacyclodextrin-iodine, polyoxyethylenepolyoxypropylene condensate-iodine, and ethoxylated linear alcohol-iodine, with polyvinyl pyrrolidone-iodine being the most preferred. The iodophor as mentioned in the present invention is characterized by enhanced bactericidal, germicidal and other biocidal activity, and reduced vapor pressure and odor. Staining is virtually non-existent and wide dilution with water is possible. [0039] The preferred pharmaceutical composition of the present invention is in the form of ointment comprising metronidazole and povidone-iodine impregnated in a suitable water soluble base. The means of formulating water soluble ointment bases are known to those skilled in the art. A water soluble base lowers surface tension of the composition aiding uniform distribution of the composition. [0040] Water soluble bases are prepared from mixtures of high and low molecular weight polythylene glycols, which have general formula HOCH 2 [CH 2 OCH 2 ] n CH 2 OH. Suitable derivatives include ethers and esters of the poly (substituted or unsubstituted alkylene) glycols, such as macrogol ethers and esters e.g. cetomacrogol; glycofurol; block copolymers including poly (substituted or unsubstituted alkylene) glycols such as block copolymers of polyethylene glycol and polypropylene glycol and cross-linked polyethylene glycols. [0041] Various grades of poly (substituted or unsubstituted alkylene) glycols and derivatives thereof may be used in combination to achieve the desired physical properties of the formulation. Preferably the formulation comprises polyethylene glycol or a derivative thereof which are commercially available in a variety of chain lengths and with a variety of consistencies. Suitable polyethylene glycols include PEG 300 and PEG 400 (liquids); PEG 1000 (semi-solids); and PEG 4000 and PEG 6000 (hard solids). [0042] These may be used singly or admixed in suitable proportions to achieve the desired consistency of formulation. A preferred combination comprises PEG 4000 and PEG 400, suitably in a ratio of from 0.5:1 to 1:5, preferably from 1:1 to 1:3; most preferably about 1:2. [0043] Typically, the vehicle comprises at least 70%, preferably at least 80%, most preferably at least 90% by weight of a pharmaceutically acceptable poly (substituted or unsubstituted alkylene) glycol or a derivative thereof. [0044] Where the pharmaceutical composition is in the form of solution the active ingredients are combined with following ingredients: [0045] Surface active agent [0046] Co-solvent [0047] Buffering agent [0048] The expression “Surface active agent” as used in this specification refers to anionic surfactant. Such a sufactant provides better surface contact of the composition with infected area. [0049] Specific preferred anionic surfactants include, but are not limited to, lauryl sulfates, octyl sulfates, 2-ethylhexyl sulfates, decyl sulfates, tridecyl sulfates, cocoates, lauroyl sarcosinates, lauryl sulfosuccinates, diphenyl oxide disulfonates, lauryl sulfosuccinates, myristyl sulfates, oleates, stearates, tallates, ricinoleates, cetyl sulfates, and similar surfactants. [0050] However, sodium lauryl sulphate is preferably used as a surface active agent in the solution composition of the present invention in an amount of 0.1% to about 5.0% by wt. and preferably, in an amount of about 0.5% by wt. based on the total wt. of the composition. [0051] The expression “co-solvent” as used in this specification refers to used in combination to increase the solubility of the solutes. Examples of preferred class are ethanol, sorbitol, glycerin, propylene glycol and members of polyethylene glycol polymer series. However, Polyethylene glycol 400 is preferably used as a cosolvent in the solution composition of the present invention in an amount of 2.5% to about 10.0% by wt. and preferably, in an amount of about 5.0% by wt. based on the total wt. of the composition. [0052] The expression buffering agent as used in this specification refers to combination of basic pH adjuster and acidic pH adjuster. [0053] Examples of preferred classes of basic pH adjusters are ammonia; mono-, di- , and tri-alkyl amines; mono-, di-, and tri-alkanolamines; alkali metal and alkaline earth metal hydroxides; alkaline phosphates and mixtures thereof. However, the identity of the basic pH adjuster is not limited, and any basic pH adjuster known in the art can be used. However, Dibasic sodium phosphate is preferably used as basic pH adjuster in the solution composition of the present invention in an amount of 2.5% to about 5.0% by wt. and preferably, in an amount of about 3.83% by wt. based on the total wt. of the composition. [0054] The preferred classes of acidic pH adjusters are the mineral acids and polycarboxylic acids. Examples of mineral acids are hydrochloric acid, nitric acid, phosphoric acid, and sulfuric acid. Nonlimiting examples of polycarboxylic acids are citric acid, glycolic acid, and lactic acid. The identity of the acidic pH adjuster is not limited and any acidic pH adjuster known in the art, alone or in combination can be used. However, Citric acid is preferably used as acidic pH adjuster in the solution composition of the present invention in an amount of 0.5% to about 2.0% by wt. and preferably, in an amount of about 1.63% by wt. based on the total wt. of the composition. [0055] The most preferred composition has a pH of below 7, most preferably between 5 to 6.5. [0056] The pharmaceutical composition of the invention in the form of ointment can be prepared as follows: Metronidazole is dissolved in a mixture of PEG 400 and water under stirring. Then Povidone-Iodine is added to above solution and dissolved under stirring. Then PEG 4000 is melted by heating to 60-65° C. and then added to the above viscous solution under stirring. The mixture is allowed to cool to room temperature to form uniform viscous ointment. [0057] The pharmaceutical composition of the invention in the form solution can be prepared by the method stated below: [0058] The buffer is prepared by dissolving dibasic sodium phosphate and citric acid in water. Povidone-Iodine is dissolved in buffer under stirring. Metronidazole is dissolved in PEG 400 under stirring and added to the above solution containing Povidone-Iodine with mixing. Sodium lauryl sulphate is dissolved in water and added to the bulk solution under stirring. The volume is adjusted with water to get the specified concentration. [0059] To investigate the effectiveness of the present invention in various types of wounds, controlled clinical trials were carried out all over India. [0060] This study is not disclosed to the public and the trials are done in confidence. The results of clinical study in India are given below. [0061] 40 patients having lacerated wound were included in the study to evaluate the efficacy and safety of Metronidazole and Povidone-Iodine ointment as described in present invention and its comparison with Povidone-Iodine ointment 5%. Patients were divided in to two groups of twenty each. Group one received treatment with Povidone-Iodine ointment 5% where as group two received treatment with Metronidazole and Povidone-Iodine ointment as described in present invention. General and wound parameters such as pain, tenderness, edema, discharge, stages of healing, final healing, type and strength of scar were recorded. Treatment was given twice a day in each group. In group one healing took place in 8 weeks where as in group 2 it took 5 weeks. The improvement in pain, tenderness, edema and discharge improved much faster in Metronidazole and Povidone-Iodine ointment group as described in present invention group compared to Povidone-Iodine 5% group. Similarly scar formation was much faster in Metronidazole and Povidone-Iodine ointment as described in present invention group than Povidone-Iodine 5% ointment. [0062] 50 patients suffering from Bacterial and mycotic skin infections were included in the trial. They were divided in to two groups 25 each. Group 1 received treatment with Povidone-Iodine ointment 5% and group 2 received Metronidazole and Povidone-Iodine ointment as described in present invention ointment. Both the ointments applied twice a day. The time for recovery, signs of inflammation and response of the lesions were monitors. All patients completed study without any side effect. The healing of lesions in Povidone-Iodine ointment 5% group occurred in 9 days while in Metronidazole and Povidone-Iodine ointment as described in present invention ointment group healing occurred in 6 days. Inflammatory parameters showed faster remission in Metronidazole and Povidone-Iodine ointment as described in present invention group than Povidone-Iodine ointment 5% group. [0063] 50 patients undergoing gastrointestinal surgery were included in the evaluation of Metronidazole and Povidone-Iodine solution as described in present invention 5% solution and its comparison with Povidone-Iodine 5% solution as pre operative and post-operative anti-sepsis. They were divided two groups of 25 each group 1 received treatment with Povidone-Iodine 5% solution as pre and post operative scrub and Povidone-Iodine 5% ointment post operatively applied twice a day on operation wound. Group 2 received Metronidazole and Povidone-Iodine solution as described in present invention 5% solution as pre and post-operative scrub and Metronidazole and Povidone-Iodine solution as described in present invention 5% ointment as application twice a day on surgical wound. There were no serious post operative wound infections in any of the group. However, healing of the wound was much faster in Metronidazole and Povidone-Iodine solution as described in present invention group than Povidone-Iodine 5% solution group. [0064] 30 patients undergoing gastrointestinal surgery were included in the evaluation of Metronidazole 1% gel and Metronidazole and Povidone Iodine ointment. 30 patients were divided in to group of 15 each Group I received Metronidazole 1% Gel in form of topical application over incision post-operatively and Group II received Metronidazole and Povidone Iodine ointment applied topically on incision post-operatively. The dressing in both the group done daily and ointment and gel were applied twice daily. There were no serious post-operative wound infection in any of the group however healing of the wound was faster in Metronidazole and Povidone Iodine ointment group compared to Metronidazole 1% gel group. [0065] Above clinical studies confirm the efficacy of the present pharmaceutical composition of this invention: [0066] From this trial it can be concluded that Metronidazole and Povidone-Iodine as described in present invention is better than Povidone-Iodine alone in the management of bacterial and mycotic skin infections. This can be attributed to the unique combination comprising Metronidazole, an anaerobicidal agent and Povidone-Iodine, an aerobicidal agent which offered significantly rapid reduction due to the synergistic effect. This can be attributed to the unique combination comprising metronidazole, an anaerobicidal agent, and povidone-iodine, an aerobicidal agent, that offers significant rapid reduction of infection due to their combined action, which increases the effectiveness of each other. [0067] The invention will now be illustrated by the following Examples: EXAMPLE 1 [0068] [0068] Metronidazole  1.00% Povidone-Iodine  5.00% Polyethylene glycol 4000 30.00% Polyethylene glycol 400 59.75% Purified Water  4.25% [0069] The ointment preparations of the invention can be prepared by dissolving Metronidazole in a mixture of PEG 400 and water under stirring. Then adding Povidone-Iodine to above solution and dissolving under stirring. Then melting PEG 4000 by heating to 60-65° C. and adding to the above viscous solution under stirring. Allowing to cool to room temperature to form uniform viscous ointment. Metronidazole  2.00% Povidone-Iodine 10.00% Polyethylene glycol 4000 30.00% Polyethylene glycol 400 59.75% Purified Water  4.25% [0070] The same procedure as used in Example 1 was repeated only change is the concentration of the metronidazole and Povidone-Iodine are different to that of Example 1. Metronidazole 1.00% Povidone-Iodine 5.00% Polyethylene glycol 400 5.00% Sodium lauryl sulphate 0.50% Dibasic Sodium phosphate 3.83% Citric acid 1.63% Purified Water 4.25% [0071] The solution preparation of this invention can be prepared by dissolving dibasic sodium phosphate and citric acid in water. In this solution dissolving Povidone-Iodine under stirring. Then dissolving metronidazole in PEG 400 under stirring and adding this solution to the above solution containing Povidone-Iodine. Mixing well. Then dissolving sodium lauryl sulphate in water and adding this to the bulk solution under stirring. Mixing well and adjusting the volume with water to get the specified concentration. Metronidazole  2.00% Povidone-Iodine 10.00% Polyethylene glycol 400  5.00% Sodium lauryl sulphate  0.50% Dibasic Sodium phosphate  3.83% Citric acid  1.63% Purified Water  4.25% [0072] The same procedure as used in example 3 was repeated only change is the concentration of the metronidazole and Povidone-Iodine are different to that of example 3. [0073] In addition the combination of Metronidazole and Povidone-Iodine may be applied or formulated contemporaneously with other topical agents to provide synergistic or amplified activity for management of wounds. [0074] It is to be understood that the example and embodiments described hereinabove are for the purpose of providing a description of the present invention by way of example and are not to be viewed as limiting the present invention in any way. Various modifications or changes that may be made to that described hereinabove by those of ordinary skill in the art are also contemplated by the present invention and are to be included within the spirit and purview of this application and the stated claims.

A pharmaceutical composition for topical application and manufacturing process thereof for treatment of microbial and mycotic infections caused by aerobic and anaerobic microorganisms is provided comprising metronidazole and Povidone-Iodine, in effective amounts. Such a composition can be administered topically to patients in need thereof in various pharmaceutical dosage forms.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of U.S. application Ser. No. 10/804,845, filed Mar. 19, 2004, which claims the benefit of U.S. Provisional Application Ser. No. 60/550,050, filed Mar. 3, 2004, which are hereby incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] Diabetes is a major cause of morbidity and mortality in industrialized societies. It has been estimated that one of every seven health-care dollars goes to treating diabetes and its complications. Type 1 diabetes (also called insulin-dependent or juvenile diabetes, henceforth referred to in this document as “diabetes”) is due to the autoimmune destruction of the insulin-producing pancreatic beta cells. Type 1 diabetes is less common than type 2, accounting for only 10-20% of cases in Caucasians. However, because it is much more severe and starts much earlier in life, it accounts for a large proportion of diabetes-related morbidity and mortality. [0003] Autoimmune destruction of the pancreatic islet beta cells is the major cause of type 1 diabetes mellitus. 1 This destruction is associated with cellular and humoral immune responses to several beta-cell autoantigens, both of which can precede clinical onset of disease. Indeed, the presence of antibodies against glutamic acid decarboxylase (GADA), insulinoma-associated antigen (IA-2A) or insulin (IAA) alone or in combination has been shown to predict type 1 diabetes. 2,3 Together with islet-cell antibodies (ICA), IA-2A and GADA are present at the time of diagnosis in 80-90% of patients with type 1 diabetes. 4 These autoantibodies, especially GADA, may also occur in up to 10% of adults initially classified as type 2 diabetes, a condition referred to as Latent Autoimmune Diabetes in Adults (“LADA”). 5 The disease process in LADA patients is in some ways similar to that in type 1 diabetes in that they share some HLA genetic susceptibility and some type 1 diabetes-associated autoantibodies. In type 1 diabetes compared to LADA, however, insulin secretion is lower and the rate of progression to insulin dependency is higher. 6,7 [0004] Preclinical studies in the spontaneously non-obese type 1 diabetic (NOD) mouse demonstrated that the destruction of pancreatic islet beta-cells was associated with T cells recognising GAD65. 8 It was also shown that small quantities of GAD65 effectively prevented autoimmune beta-cell destruction and reduced or delayed the development of spontaneous diabetes. 8-14 [0005] Given the irreversibility of the destruction of pancreatic beta cells, it is desirable to provide a treatment for autoimmune diabetes where it cannot be otherwise prevented. Although the specific causative autoantigen(s) in diabetes is/are not known, insulin, the main product of the beta cell appears to be an autoantigen of major importance. Accordingly, it is desirable to have safe and efficacious medications and treatment and prevention methods and regimes for autoimmune diabetes, as well as treatments for all diabetes types. [0006] Based on the pre-clinical data presented herein, controlled clinical studies were initiated to assess the potential of recombinant human GAD65 to halt beta-cell destruction and prevent or reduce insulin dependence. Following extensive pre-clinical safety evaluation and one clinical phase I trial with the bulk rhGAD65 without adjuvant, a phase II study with rhGAD65 formulated with alum (the medication in accordance with the present invention) was conducted in LADA-patients. The study objectives were to investigate the clinical safety of the subcutaneously administered medication of the present invention, and to assess its impact on the immune system and diabetic status, and to identify an immunomodulatory dose level. SUMMARY OF THE INVENTION [0007] The present invention relates to methods and formulations for preventing autoimmune diabetes and for treatment of human diabetes in general. [0008] In general terms, the invention includes a method of treating diabetes in a human comprising administering to a the human an effective amount of a human recombinant GAD65 protein and at least one adjuvant for an effective time so as to stimulate the production of insulin in the human to a level above that existing prior to the administration. [0009] The administration may be by any acceptable means, such as by subcutaneous injection or use of an implant. [0010] The adjuvant may be any pharmaceutically acceptable adjuvant substance, such as aluminum hydroxide. [0011] The human recombinant GAD65 protein is administered in a dosage such that the human recombinant GAD65 protein is at a level of at least 20 micrograms, preferably in the range of from about 20 micrograms to about 500 micrograms. [0012] Following the first administration of the human recombinant GAD65 protein, additional booster dosages may be given over a treatment period (typically 4-24 weeks), preferably at a level of at least 20 micrograms and most preferably in the range of from about 20 micrograms to about 500 micrograms. [0013] The invention also includes a method of suppressing or reducing the immune response of a human to glutamic acid decarboxylase comprising administering to the human an effective immunosuppressive dose of human recombinant GAD65 protein, so as to help prevent autoimmune diabetes. [0014] The administration methods, adjuvants, dosage and booster levels and ranges may be as given above. [0015] The level of beta cell function may be determined through measurement of CD4+ lymphocytes prior to the at least one booster dosage as described herein. [0016] The invention also includes a pharmaceutical composition for suppressing or reducing the immune response of a human to glutamic acid decarboxylase comprising a dosage form whose components comprise an effective immunosuppressive dose of human recombinant GAD65 protein and a pharmaceutically acceptable adjuvant. [0017] The method of the present invention thus also includes generally a method to increase insulin production in a diabetes patient with beta cell antibodies, the method comprising administering to a human an effective amount of beta cell antigens in a pharmaceutical carrier for an effective time so as to stimulate the production of insulin in the human to a level above that existing prior to the administration. [0018] The beta cell antigens that may be used in the method of the present invention include at least one from the group: GAD65, GAD67, insulin, insulin-peptide, proinsulin, proinsulinpeptide, sulfatide, heat schock protein, S100 beta protein, IA-2, or any peptide, altered peptide ligand, chimeric molecule, or conjugated molecule or fragment of any of the above. [0019] The aforementioned methods may be practiced by replacing at least one of the beta cell antigens with DNA or RNA nucleotides coding for at least one from the group: GAD65, GAD67, insulin, insulin-peptide, proinsulin, proinsulinpeptide, sulfatide, heat schock protein, S100 beta protein, IA-2, or any peptide, altered peptide ligand, or by anti-sense oligos to at least one of the nucleotide. [0020] These methods may be carried out with at least one of the aforementioned components are produced recombinantly in a prokaryotic expression system capable of posttranslational palmitoylation. This may be done with any appropriate expression system, such as for instance baculovirus is grown in Spodotera frugiperda 9 (Sf9) cells. [0021] The administration of the antigen may be by any effective and appropriate method, such as subcutaneous administration, intravenous administration and oral administration; or by gene therapy. [0022] Although all effective amounts are included in the subject disclosure, it is typical, and preferred, that each of the administered components are administered in a dosage such that at least one of the components is in the range of from about 5 micrograms to about 100 micrograms or, in other terms, in the range of from about 0.001 mgs/kg to about 0.1 mgs/kg. [0023] The method of the present invention may also include the optional administering of at least one booster dosage of the components following the first administration, and wherein the booster is administered in a dosage such that at least one of the components is in the range of from about 5 micrograms to about 100 micrograms. [0024] The at least one booster dosage of the components preferrably is administered in a dosage such that at least one of the components is in the range of from about 0.001 mgs/kg to about 0.1 mgs/kg. [0025] The method of the present invention may also be described as a method to treat beta cell inflammation by means of in vivo activation of regulatory CD4+CD25+ T cell subsets. This may be done as a method to activate regulatory CD4+CD25+ T cells by means of administering an effective amount of at least one components described above. [0026] The invention also includes a pharmaceutical composition for treatment of diabetes comprising of at least one of the aforedescribed components where at least one of the components is produced according to the methods of the present invention described herein. [0027] The invention also features a pharmaceutical composition as described herein, preferrably wherein Zwittergent is included in a concentration relation to at least one of the components in a relative ratio of between about 1:1 to about 1:8. The preferred pharmaceutical composition includes a pharmaceutical carrier such as alum, preferrably species specific serum albumin, such as human serum albumin. [0028] One of the findings are that an effective dosing regimen, such as a 20 microgram dose prime and boost regimen, improves beta cell function in most patients and that this can be verified by looking at an increase in a subset of CD4+ lymphocytes namely the CD4+CD25+ lymphocytes. The increase may be measured in absolute terms or CD4+CD25+ in relative terms such as the quotient CD4+CD25+/CD4+CD25−. [0029] If an increase of CD4+CD25+ cells is not seen a reboost may be given. If no increase another reboost. In fact to look for an increase in CD4+CD25+ cells is a way to look for efficacy of other treatments for other autoimmune diseases as well. [0030] It has also been found that the medication of the present invention not only maintained the beta cells' capacity to produce insulin (measured as C-peptide) which was expected—but indeed, unexpectedly did the insulin production increase significantly (measured as c-peptide). This means that the present invention may have allowed new beta cells to regenerate and to produce more insulin. It may also mean that the present invention may have turned off the inflammation in the beta cells and thus cleared the milieu so that increased insulin production was allowed. So the present invention may now bee used as a treatment for type 1 and type 2 diabetes, not only a vaccine to avoid acquiring type 1 diabetes. [0031] A study of the treatment in accordance with the present invention determined that alum-formulated human recombinant GAD65 given to patients with Latent Autoimmune Diabetes in Adults (LADA) is safe and does not compromise beta cell function, and was aimed at identifying an immunomodulatory dose for further clinical development. [0032] This study was conducted as a randomised, double blind, placebo-controlled, dose-escalation clinical trial in a total of 47 LADA patients who received either placebo or 4, 20, 100 or 500 μg of the medication in accordance with one embodiment of the pre subcutaneously at weeks one and four. Safety evaluations including neurology, beta-cell function tests, diabetes status assessment, haematology, biochemistry and cellular and humoral immunological markers were repeatedly assessed over 24 weeks. [0033] None of the patients had significant study-related adverse events. Fasting c-peptide at 24 weeks increased compared to placebo (p=0.0011) in the 20 μg but not in the other dose groups. In addition, both fasting (median 36%, p=0.008) and stimulated (median 19%, p=0.0156) c-peptide increased from baseline to 24 weeks in the 20 μg dose group alone. GADA levels clearly increased (p<0.001) in response to 500 μg of the medication of one embodiment of the present invention. An increase in CD4 + CD25 + /CD4 + CD25 − T cell ratio was positively correlated with a change in fasting (r=0.51; p<0.005) and stimulated (r=0.34; p<0.05) c-peptide levels over 24 weeks. [0034] The positive findings of this study of clinical safety and efficacy supports further clinical development of the present medication compositions and treatments as a therapeutic to prevent autoimmune diabetes. [0035] It is an object of the present invention to provide a method for treating autoimmune diabetes in man. BRIEF DESCRIPTION OF THE DRAWINGS [0036] FIGS. 1A-1E are graphs of the percentage change in log GAD antibody levels (U/ml) before and at 4, 8, and 24 weeks from prime dose of the medication of the present invention, wherein the individual patients in the (A) Placebo, (B) 4 μg, (C) 20 μg, (D) 100 μg dose and (E) 500 μg dose groups are shown, in accordance with one embodiment of the invention. [0037] FIGS. 2A-2C are graphs of the median percentage change before and at 8, 12 and 24 weeks from prime dose shown for the placebo, 4 μg, 20 μg, 100 μg and 500 μg dose groups, respectively as follows: (A) Effects on HbA 1c ; *p=0.013, (B) Effects on fasting c-peptide/glucose; *p=0.0078 and + p=0.0008, and (C) Effects on post-Sustacal® c-peptide/glucose. *p=0.0391 at 20 μg and p=0.0312 at 500 μg, in accordance with one embodiment of the invention. [0038] FIGS. 3A and 3B are graphs of the mean change before and at 8 and 24 weeks from prime dose are shown for the placebo, 4 μg, 20 μg, 100 μg and 500 μg dose groups in respectively as follows: (A) CD4/CD8 ratio, and (B) CD4 + CD25 + /CD4 + CD25 − ratio, showing an increase in the ratio of CD4 + CD25 + /CD4 + CD25 − cells over time (*p=0.012) and relation to placebo ( + p=0.03), in accordance with one embodiment of the invention. [0039] FIGS. 4A and 4B are graphs of results showing change in fasting C-peptide levels in individuals studied in accordance with one embodiment of the method of the present invention. [0040] FIGS. 5A-5Y are graphs of results from this a phase II clinical study in accordance with one embodiment of the present invention. [0041] FIG. 6 is a graph describing induction of GAD65-specific regulatory T cells in NOD mice. [0042] FIG. 7 is a chart describing the patient disposition in a Phase II trial conducted using a method in accordance with one embodiment of the present invention. [0043] FIG. 8 is a graph describing C-peptide/glucose at 6 months, 12 months and 18 months in a Phase II trial conducted using a method in accordance with one embodiment of the present invention. [0044] FIG. 9 is a graph describing the log of fasting C-peptide/fasting glucose at 6 months, 12 months and 18 months in a Phase II trial conducted using a method in accordance with one embodiment of the present invention. [0045] FIG. 10 is a graph describing HbA 1c (%) at 6 months, 12 months and 18 months in a Phase II trial conducted using a method in accordance with one embodiment of the present invention. [0046] FIG. 11 is a graph describing the log of GAD65Ab at 6 months, 12 months and 18 months in a Phase II trial conducted using a method in accordance with one embodiment of the present invention. [0047] FIG. 12 is a graph describing the change in CD4 + CD25 + /CD4 + CD25 − T cell ratio in a Phase II trial conducted using a method in accordance with one embodiment of the present invention. [0048] FIG. 13 is a graph describing the percent of treated and control LADA patients receiving insulin in 24 Months in a Phase II trial conducted using a method in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0049] In order to treat autoimmune diabetes, the following provides an example of one embodiment that demonstrates the safe efficacy of the present invention. This is considered to be the best mode of the invention. [0000] Trial Design [0050] The study design was a randomised, double blind, placebo-controlled, group comparison, dose-escalation study conducted in LADA patients at the Department of Endocrinology, University Hospital MAS, Malmö, and the Department of Medicine, St. Gorans Hospital, Stockholm, Sweden. A total of 47 patients were allocated to either one of four groups receiving 4 (n=9), 20 (n=8), 100 (n=9), or 500 μg (n=8) of the medication of the present invention, or placebo (n=13). Sequential immunisation of each dosage group was conducted once the absence of safety issues were determined at lower doses. Interim safety evaluation to approve dose escalation was conducted by a separate committee 4 weeks after receipt of an injection of the medication of the present invention. In each group, nine patients were planned to receive the medication of the present invention, and three to receive placebo. Patients treatment allocation was centrally organised by Chiltern International Ltd., Slough, Berkshire, UK. [0051] Patients were eligible to enter the trial if they fulfilled the following entry criteria at Visit 1:1) male or female patients aged 30-70 years, 2) diagnosed with diabetes and classified with type 2 diabetes within the previous 5 years, 3) presence of GADA, 4) only requiring diabetes treatment with diet, oral hypoglycaemic agents, or both, 5) females of non child-bearing potential, 6) absence of associated serious diseases or conditions which in the opinion of the investigator would exclude the patient from the trial, and 7) patients who had given written informed consent at the screening visit. [0052] After all patients in the 4 μg dosing group had completed visit 8 (week 8), and provided that there were no safety concerns, the next schedule of visits for the 20 μg dosing group was initiated. The same procedure was repeated for the 20, 100 and 500 μg groups. In addition, a maximum of two additional booster injections was allowed in the 500 μg dose group alone depending on the patients GADA response. The criterion for additional booster injections in the top dose group were a GADA titre that remained unchanged at week 8 (defined as less than a doubling of titre prior to receipt of the first dose) and the absence of safety concerns for that patient. A final booster injection (i.e. 4 th administration) was performed if there was still no change in GADA titre four weeks after the initial booster injection and if no safety concerns were apparent. All patients stayed at the hospital overnight for safety observation after each injection. [0053] During the 24-week study period, each patient was followed at regular intervals as outpatients with a total of 10 study visits during which assessment of immunological markers, diabetic status, fasting lipids, haematological and biochemical parameters, as well as physical examinations, reporting of concomitant medication and adverse effects were performed. GADA and IA-2A were determined as previously described. 15 Our laboratory is number 156 in the Diabetes Antibody Standardisation Program (DASP) for GADA and IA-2A. 16 Diabetes status assessment included fasting glucose, fasting and 2-hr Sustacal® stimulated c-peptide, and long-term metabolic control assessed by HbA 1c . Blood samples for haematology were analysed for haemoglobin, red cell count (including MCV and MCHC), haematrocrit ratio (PCV), white cell count, differential white cell count and platelets, and biochemical parameters included analysis of plasma levels of glucose, c-peptide, HbA 1c , urea, creatinine, phosphorus, total bilirubin, alkaline phosphatase, alanine transferase, glutamyl transferase, lactic dehydrogenase, amylase, albumin, c-reactive protein, total protein and fasting lipid and lipoproteins. Clinical neurological assessment and EMG were performed at baseline and after 6 months to detect any adverse effects on the neuromuscular system. 17,18 [0000] Patients [0054] Patient characteristics for patients receiving placebo and for the four dose groups at baseline are given in Table 1. All patients remained in the study for 24 weeks. One patient given placebo started insulin treatment at 12 weeks along with one patient in each of the 100 μg and 500 μg groups, who started insulin treatment after 12 but before 24 weeks. At week 24, only fasting c-peptide was available from these patients. For technical reasons, c-peptide were not available at week 24 from one patient in the placebo (fasting) and another in the 100 μg (stimulated) group, respectively. Three patients did not complete the study for personal reasons, one each in the 4, 20 and 100 μg groups. [0000] Test Substances [0055] Sterile, pre-filled vials of the medication of the present invention were provided by Diamyd Therapeutics AB, Stockholm, Sweden for clinical trial use. The unmodified recombinant form of human GAD65 (bulk rhGAD65) was formulated with aluminium hydroxide, such as that sold under the trademark Alhydrogel®. The bulk rhGAD65 was manufactured using baculovirus/insect cell expression of the cDNA for hGAD65. 19 Both manufacture of the bulk rhGAD65 and that of the medication of the present invention were performed under strict conditions of current Good Manufacturing Practice. Each vial contained a sterile formulation of either 4, 20, 100, or 500 μg of the medication of the present invention having a constant amount of Alhydrogel®. Coded vials containing an identical amount of Alhydrogel® alone were used as placebo. [0000] Flow Cytometric Analysis [0056] Flow cytometric analysis of lymphocyte subsets was conducted using standard techniques. Whole blood was stained at room temperature for 20-30 minutes with monoclonal antibodies against CD3, CD4, CD8, CD25, CD19, CD56 and CD16 (all from Becton Dickinson, Calif., USA). Erythrocytes were lysed using a FACS® tradeamrk lysis buffer containing paraformaldehyde (Becton Dickinson, CALIFORNIA, USA). Thereafter, cells were washed, resuspended in staining PBS buffer containing 0.5% bovine serum albumin and 2 mM EDTA (pH 7.4) and analysed within 24 hrs using a FACSCalibur® (Becton Dickinson, Franklin Lakes, N.J., USA) and CellQuest® software (Becton Dickinson). Between 10,000 and 50,000 events were acquired and the absolute number of each subset was calculated by multiplying the percentage of cells by the total lymphocyte count obtained at the hospital clinical laboratory for the same blood sample. Isotype-matched control antibodies (IgG2a FITC) were used to set the dot plot quadrant and calculate the percent of CD4 + CD25 + lymphocyte population. [0000] Statistical Analysis [0057] All graphs and analyses were performed using Splus6.1 (from Insightful Corp., Seattle, Wash.). Two-sample t-test was used for differences in means between variables normally or symmetrically distributed. When distributions were not symmetric, medians were used as a summary measure and the corresponding Wilcoxon two-sample test was used to evaluate statistical significances. Change in plasma glucose, c-peptide and HbA 1c for each subject was presented as percent change in level from baseline. Change in T cell counts was summarised as change in ratio totals. Multiple linear regression was used to test whether differences observed in the univariate analyses remained after adjusting for variables such as age, BMI and gender as well as GADA and IA-2A. C-peptide was log transformed to assure normality and constant variance assumption. The 4 μg dose group was considered as having no effect and was therefore combined with placebo as controls and compared to a treatment group. Spearman's correlation coefficient tested the association between change in c-peptide levels and change in CD25 + /CD25 − composition within CD4 + T cells. P-values less than 0.05 were considered significant. [0000] Results [0000] Study-Related Adverse Events [0058] There were 32/47 patients (68%) with 51 adverse events (AE). The majority experienced influenza-like symptoms, with nasopharyngitis being the most common AE. Prior to study completion and unblinding three AEs were judged to be probably related to the trial treatment, i.e. vitiligo (later found to be in the placebo group), mild leukocytosis (100 μg dose group) and a mild inflammation at the injection site on the left arm (500 μg dose group). As a precautionary measure the patient with vitiligo was withdrawn from the trial two weeks after the first injection. However, leukocytosis and inflammation were completely resolved in the two other patients and no separate treatment was required. There were no severe AEs or deaths during the trial. [0059] Injection site reactions were absent at the majority of visits. All reactions were mild and most, in particular tenderness, occurred primarily on the day of the first injection (day 1) and on the day of the second injection (week 4). [0060] Mean haematology and biochemistry parameters were within normal limits in each treatment group at most visits. There were no significant changes from baseline (day 1) in any of the parameters except for two patients had abnormal clinically significant laboratory results; one patient (20 μg dose group) having raised liver enzymes and another (placebo dose group) having raised blood iron levels, later diagnosed with haemochromatosis. [0061] There were no differences between treatment groups in blood pressure or pulse rate, no deterioration in neurological assessment, muscle tone and spasms, and no abnormal EMG assessments. [0000] GAD65 Autoantibody (GADA) Levels [0062] The percentage change in GADA levels from day 1 for all patients and all groups indicate no change after 1, 4 (when the boost injection was given), 8 and 24 weeks in the placebo ( FIG. 1A ) and 4 μg ( FIG. 1B ) groups. Levels in the 20 μg dose group did not change during the first 4 weeks; however, between 8 and 24 weeks 7/8 (88%) patients showed a decline ( FIG. 1C ). Similarly, in the 100 μg dose group there was a decline in 8/9 (89%) patients despite an increase in three patients between 4 and 24 weeks ( FIG. 1D ). In these two groups the number of patients with a decline (15/17) was different from the placebo group (6/13; p<0.05). All eight patients in the 500 μg group developed either an early increase before week 4 or a gradual increase after additional boost injections during the 24 weeks ( FIG. 1E ). [0000] Blood Glucose and HbA 1c Levels [0063] There were no changes in fasting blood glucose during the first 24 weeks. Within the placebo group, however, there was considerable variability in percentage change. An increase in HbA 1c levels (p=0.01) was found in the placebo but not in the other dose-groups ( FIG. 2A ). [0000] Fasting and Stimulated C-Peptide [0064] The groups did not differ in fasting c-peptide levels at visit 2 (Table 1). However, the 20 μg dose group showed an increase in fasting c-peptide compared to placebo (p=0.0011) as well as an increase in both fasting (36%, p=0.008) and stimulated (19%, p=0.0156) c-peptide at 24 weeks. This effect was also evident when the data were calculated as a function of c-peptide/glucose ( FIGS. 2B and C) and compared to both baseline (47% increase, p=0.0078) and to placebo (p=0.0008) ( FIG. 2B ). An increase in levels compared to baseline within the 20 μg group was also recorded in stimulated c-peptide/glucose (24% increase, p=0.0391) ( FIG. 2C ). A decline in stimulated c-peptide/glucose levels was apparent in the 500 μg dose group (p=0.03). Patients given placebo or the 4 μg dose had almost identical changes in c-peptide/glucose ratio during the 24 weeks follow-up ( FIG. 2C ). [0000] Blood Lymphocytes and T Cell Subsets [0065] At day 1 and during the 24 weeks of observation no differences between the groups were observed in total CD3 + , CD4 + , or CD8 + T cells, B cells, NK cells or T cells with NK cell markers or in the CD4 + /CD8 + T cell ratio (data not shown). In contrast, we observed that the ratio of CD4 + CD25 + /CD4 + CD25 − T cells increased (p=0.012) over time in the 20 μg group, but not in the other groups ( FIG. 3 ). This change was also different from the placebo group (p=0.03, FIG. 3 ). There was a positive correlation in all medication-treated patients between change in CD4 + CD25 + /CD4 + CD25 − T cell ratio and change in fasting c-peptide (r=0.51; p<0.005) as well as in post-Sustacal® c-peptide (r=0.34; p<0.05), demonstrating that patients exhibiting an increase in c-peptide also had an increase in CD4 + CD25 + /CD4 + CD25 − T cell ratio. [0000] Multiple Linear Regressions [0066] Changes in HbA 1c , fasting glucose, fasting and stimulated log c-peptide in the control (n=21) were compared to the treatment (n=24) group. Unadjusted analyses confirmed the increase compared to controls in fasting log c-peptide (+0.208, p=0.025) and a decrease in HbA 1c (−0.603, p=0.024). The effect on fasting log c-peptide remained after adjusting separately for age, gender, BMI, HbA 1c at baseline as well as GADA and IA-2A. [0000] Findings and Discussion [0067] The results of the study support the clinical safety of subcutaneous administration of alum-formulated recombinant human GAD65 as well as its ability to increase c-peptide levels and affect the CD4 + CD25 + T cell subset in peripheral blood. [0068] Cutaneous reactions to the treatment of the present invention were minor and of no clinical significance. These findings support the results of a phase I clinical study demonstrating that subcutaneous administration of rhGAD65 was well-tolerated. In the study of the present invention, inclusion of a patient group receiving a provisional no effect dose level (4 μg) was intended to provide clinical outcomes indistinguishable from placebo and from which dose escalation could be safely performed. The additional booster injections with 500 μg of the medication of the present invention were intended to maximise the likelihood of immunomodulation resulting therefrom (apparent as a doubling in GADA). Three patients in the 500 μg dose group received additional injections. Of these, two patients received one additional injection (a total of 3 injections) and one patient received two additional injections (a total of 4 injections). No study-related adverse events were observed in any of the patients in the 500 μg group despite a more than two-fold increase in GADA. The stimulatory effects of 20 μg of the medication of the present invention on both fasting and stimulated (post-Sustacal®) c-peptide was observed when the patients were either compared to their change from baseline or when compared to the placebo group. It is possible that the c-peptide response to the medication of the present invention is dependent on both the dose and the individual since some of the patients receiving 100 μg of the medication also showed an increase in fasting c-peptide levels. It is also noted that patients receiving 500 μg of the medication tended to show a decline in fasting c-peptide, indicating a possible dose dependent effect. The effects of 20 μg of the medication on both fasting and stimulated c-peptide were statistically significant whether or not these were calculated as c-peptide/glucose ratio or c-peptide levels alone. As the increase in c-peptide levels in the 20 μg medication dose group was not associated with a corresponding decrease in HbA 1c levels, the increase in c-peptide was probably not an effect of decreased glucose toxicity on the beta cell. However, the positive correlation of CD4 + CD25 + T cells to the increase in c-peptide in the 20 μg dose group suggests an immunomodulatory mechanism. Further evidence for immunomodulation is provided by the median decline in log GADA after 20 μg (−0.17 U/ml) and 100 μg (−0.33 U/ml) of the medication, indicating a possible suppressive effect on GADA production. This suppressive effect may be explained by an increase in CD4 + CD25 + T cells since the CD4 + /CD25 + /CD4 + CD25 − ratio among patients in either the 20 or 100 μg dose groups showing a decline in GADA correlated to an increase in fasting c-peptide (r=0.83; p<0.005). These results also support the increase in c-peptide being related to a quantitative increase in CD4 + CD25 + T cells. [0069] CD4 + CD25 + T cells are regarded as regulatory T cells 20,21 and in experimental animals their presence confer inhibition of autoimmunity. 22 Although not limited by the mechanism of the invention, several mechanisms may explain the positive effect on c-peptide levels in patients receiving 20 μg (and in some receiving 100 μg). First, 20 μg of the medication may induce specific T cells recognising immunodominant GAD65 epitopes. These GAD65-specific regulatory T cells would down-regulate existing GAD65 autoreactive T cells and thereby preserve c-peptide. As a second possibility, non-antigen specific CD4 + CD25 + T cells may be induced in numbers sufficient to allow their detection in peripheral blood. 23 As such, CD4 + CD25 + T cells were shown to be immuno-suppressive 24 their greater number could possibly down-regulate self-reactive T cells, thereby inhibiting T-cell-mediated beta cell killing. As no changes in other lymphocyte subsets were found, the present treatment could be considered immunologicaly safe with regard to its clinical impact on peripheral lymphocytes. [0070] The effect of the medication of the present invention may be highly dose dependent, as is well-known in specific immunomodulation of certain allergies. In addition to T cell subset immunomodulation, administration of the medication may also impact on B cell activity, since GADA levels in the 20 μg and all but three patients in the 100 μg dose groups tended to decrease over time. Indeed, it cannot be excluded that therapeutic activity also extends to the 100 μg dose level, since some of these patients showed an increase in fasting c-peptide that was associated with an increase in CD4 + CD25 + ratio and a decrease in GADA. Although it is possible that the immune response to administration of low levels of the medication involves a shift towards less aggressive cytokines produced by certain T cell subsets, the effect of 20 μg dose does not suggest a shift from a Th1 to a Th2 response, as this would otherwise be indicated by an increase in GADA. 13 Rather, because of their reported regulatory activity 20,21 and their demonstrated decrease in conditions of autoimmunity, 22,23 the induction of CD4 + CD25 + T cells by low doses of the medication suggest a novel mechanism by which autoimmunity is down-regulated. [0071] GAD65 immunomodulation in GAD65 autoantibody positive type 2 diabetes patients was studied to determine the immunomodulation of GAD-specific autoimmunity as a potential therapy of type 1 diabetes. A phase II clinical trial on 47 GAD65 autoantibody positive type 2 diabetes patients previously reported no severe adverse events after six months. The primary aim was to examine if the proposed invention was still clinically safe after 12 months. A secondary goal was to determine whether GAD65 administration prevents progression to insulin dependency after one year. Patients with LADA received placebo or 4, 20, 100 or 500 μg subcutaneously at weeks 1 and 4 in a randomised, double blind, group comparison dose-escalation study. Beta-cell function tests were performed at 2, 6, 9 and 12 months. The 4 μg was a non-effect dose group and therefore combined with placebo to form a control group. None of the patients showed significant study related adverse events and there was no sign of beta-cell collapse. While 4 of 47 received insulin before 6 months, 7 of 43 patients became insulin dependent between 6 and 12 months, and an additional 3 of 43 dropped out for unrelated reasons. Of these insulin-dependent patients 6 of 19 where controls, 1 of 8 was given 20 μg, 0 of 7 100 μg and 0 of 6 500 μg doses (p<0.05). Of the remaining 33 patients followed for the entire year, HbA1c level at the start of the study in treatment patients correlated with a decline over 12 months (n=20; r=0.84; p<0.0005), but no such association was seen in the control group (n=13; r=0.32; p=NS). Fasting and stimulated C-peptide levels, which increased in the 20 μg dose group after first 6 months, remained unchanged in the second 6 months. One year follow-up confirm that alum-formulated recombinant human GAD65 is safe. Patients receiving 20 μg show no evidence of further decline in beta-cell function between 6 and 12 months. FIGS. 5A-5Y are graphs of results from this a phase 11 clinical study in accordance with one embodiment of the present invention. [0072] In conclusion, the main outcomes of this phase II clinical trial support the clinical safety of the treatment and prevention methods of the present invention, together with evidence for the therapeutic efficacy of a 20 μg dose as reflected by an increase in both fasting and stimulated c-peptide. Evidence for this effect being mediated by an increase in regulatory T cells was also obtained. [0073] Additional data was also obtained from an 18 month and 24 month follow-up study as described below. [0074] Therapeutic Rationale [0075] The majority of patients with insulin dependent (Type 1) diabetes, and also a 10% subset of non-insulin dependent (Type 2) diabetes patients (i.e. those with antibodies to GAD65), are currently recognised as having an autoimmune form of diabetes. [0076] Although the contribution by the different components of the immune system is different for different autoimmune diseases, it is generally understood that the destructive process in autoimmune diabetes is orchestrated and executed by T lymphocytes, not antibodies. While this destructive process is primarily contributed to by autoreactive cytotoxic T lymphocytes (i.e. displaying the CD8+ cell surface marker) their activity is controlled by another lymphocyte subclass, T “helper” cells (instead displaying the CD4+ marker). T helper cells are therefore providing important regulatory functions in the activity of cytotoxic lymphocytes, and their manipulation provides a potent target for therapeutics to treat or prevent autoimmune diseases. [0077] Interest in GAD65 in Type 1 diabetes stems from observations in the 1980s of the frequent occurrence (˜90%) of antibodies to GAD65 in patients with insulin-dependent diabetes. Since then, the clinical presence of GAD65 antibodies has become increasingly accepted as both a diagnostic and prognostic marker for this disease. Most importantly pre-clinical and clinical studies have confirmed the GAD65 protein as the most important autoantigen in the prediction and prevention of autoimmune diabetes. [0078] In animal models for different autoimmune diseases, the appropriate administration of the autoantigen itself has been found capable of precipitating, as well as preventing, the associated autoimmune disease. These findings therefore provide strong support for the involvement of specific antigens in the aetiology of autoimmune diseases and also, conversely, of the possibility for “antigen-specific tolerisation therapies” in their treatment and cure. [0079] Briefly, tolerisation involves the appropriate presentation of the autoantigen itself back to the immune system to enable an immune “re-programming” process to occur. It seems that the appropriate dose regimen, i.e. the quantity, route, frequency, adjuvant etc required for each autoantigen/autoimmune disease, is critical in determining which of several tolerisation mechanisms are activated. If the appropriate immune mechanism is engaged, then tolerisation to that autoantigen will occur and autoimmunity will be extinguished. [0080] By way of background, in November 1993, two independent research groups in the U.S. simultaneously reported (in the scientific journal “Nature”) that administration of microgram quantities of GAD65 could induce tolerance and prevent insulin requirement in the NOD mouse pre-clinical model. Since then, the capability of GAD65 as a toleragen to prevent autoimmune diabetes has been confirmed experimentally in several independent laboratories. These include research groups at UCLA (Tian et al), Stanford (Tisch et al), Hopital Necker (Pleau et al) and University of Calgary (Yoon et al). [0081] The immune mechanisms involved in GAD65 tolerisation in NOD mice have since been intensely investigated. Several published reports now support this type of immunomodulatory mechanism being evoked early in GAD65 tolerisation, and the down-regulation in autoimmunity that this induces is sufficient to preserve beta cell function and prevent exogenous insulin requirement. [0082] Particularly because of close similarities in the NOD mouse model to its clinical counterpart, these pre-clinical findings support the possibility of rhGAD65 administration providing a clinical therapeutic for the prevention and treatment of autoimmune diabetes. Accordingly, administration of microgram quantities of alum-formulated rhGAD65 (referred to as “Alhydrogel-Diamyd™”) via an immunomodulatory “prime-and-boost” dose regimen to patients with autoimmune diabetes is proposed for therapeutic evaluation. The intended preservation of beta cell function is proposed to be clinically manifested by an increase in levels of insulin (or its surrogate: C-peptide) and result in prevention or delay in time to insulin requirement in diabetes patients with GAD65 antibodies. [0000] Target Product Profile [0083] The target product profile is supported by experimental data, but remains to be confirmed through continued clinical trials. Property Target Product Profile Indication Indicated for the treatment of Type 1 diabetes patients and Type 2 diabetes patients with GAD antibodies Contraindications None identified in clinical trials conducted to date Dosage 20 μg Dosage Regimen Initiaal prime followed by a boost after one month. Additional boost after six months if indicated by a decrease in or unchanged C-peptide levels Yearly boosts thereafter if indicated by a decrease in C-peptide levels compared to previous visit If decrease or unchanged C-peptide levels after three injections (one prime and two boosts) the treatment is terminated Efficacy >30% increase in C-peptide levels in fasting patients. Maintained or decreased existing insulin requirement (as a measure of beta cell function) Shel Life 3 years Clinical Development [0084] Clinical trials have been conducted with the Diamyd™ product available at different stages in development. The first clinical study used “laboratory grade” Diamyd™ Bulk Drug in a skin “prick test” study in selected volunteers. This was followed by a Phase I clinical trial in volunteers using GLP-grade Diamyd™ Bulk Drug from the commercial manufacturing process. The Phase II clinical trial in LADA patients has recently been completed with the (GMP) Alhydrogel-Diamyd™ formulation. Study Individuals Study Location & Study (& Study Study Type CRO dates Number) Endpoint(s) Outcome Skin Sweden 11 Feb Type 1 Delayed No DTH Prick-Test (Karolinska 1995 Diabetics Type Reactions GAD Hospital) (7) Hyper- No AEs & Healthy sensitivity controls (DTH) (8) Phase I UK Jan-Dec Healthy Safety/ Safe (Pharmaco,-LSR) 1999 volunteers Tolerability Well-tolerated (24) Phase II Sweden May 2001- LADA Safety/ No treatment (Chilterm Apr 2003 Patients Efficacy related AEs International) (47) Efficacy in 20 μg dose group (C-peptide) Immuno- modulation demonstrated Phase II Study Design [0085] A Phase II randomized, double blind, placebo controlled, group comparison dose escalation study was performed in a total of 47 patients. The study was designed to assess both safety and efficacy of treatment with Alhydrogel-formulated Bulk drug (Diamyd™). [0086] Patient disposition is shown in FIG. 7 . There were 39 males (83.0%) and 8 female (17.0%) patients randomised in the trial. There was a similar number of female patients in the placebo, 4 μg , 20 μg, and 100 μg dose groups, however there were no female patients in the 500 μg dose group. [0087] All study groups were comparable with regard to age, BMI, and basal levels of fasting glucose, fasting and meal-stimulated C-peptide, and HbA 1c as seen in Table 1 below. Baseline Characteristics Group 1 Group 2 Group 3 Group 4 Placebo (4 μg) (20 μg) (100 μg) (500 μg) n 13 9 8 9 8 Age (years) 56 (37-66) 58 (39-69) 57 (48-67) 57 (30-69) 53 (39-62) Males (n) 12 7 6 6 8 Log GADA (U/ml) 4.6 (3.3-13.3) 5.0 (3.9-9.4) 4.1 (3.5-7.3) 3.8 (3.4-7.8) 4.7 (3.3-7.5) BMI (kg/m 2 ) 26 (23-32) 27 (20-35) 28 (23-33) 27 (20-39) 26 (21-33) HbA1c (%) 5.9 (4.7-7.4) 6.7 (5.5-10.9) 5.9 (5.1-9.9) 6.0 (4.6-7.11 6.0 (5.4-8.1) P-glucose (mmol/L) Pre-Sustacal 7.8 (5.5-9.5) 9.6 (5.9-15.8) 9.1 (6.3-17.4) 7.7 (6.2-9.0) 9.1 (6.3-15.1) P c-peptide (nmol/L) Pre-Sustacal ® 0.67 (0.3-1.7) 0.6 (0.3-1.6) 0.7 (0.5-1.4) 0.7 (0.3-1.5) 0.6 (0.3-1.8) Post-Sustacal ® 1.6 (0.5-3.7) 1.3 (0.7-2.9) 1.5 (1.0-2.0) 2.0 (0.6-3.9) 1.3 (0.8-5.1) IA-2A positive (n) 1 0 2 1 1 Total T-cells (× /10 9 /L) 1.3 (0.7-2.0) 1.1 (0.8-1.6) 1.3 (0.8-2.0) 2.0 (0.9-2.4) 1.1 (0.6-2.0) CD4+/CD8+ ratio 1.7 (0.8-3.8) 1.6 (0.7-9.3) 1.2 (0.8-3.2) 1.8 (1.1-4.9) 1.9 (1.0-3.0) CD4+ CD25+/ 0.18 (0.05-0.27) 0.20 (0.17-0.32) 0.15 (0.08-0.27) 0.20 (0.07-0.28) 0.09 (0.03-0.35) CD4+ CD25− ratio Median values (range) are shown Study Endpoints [0088] Apart from routine safety variables such as Clinical Examination and Adverse Event reporting and assessment, special emphasis was put on evaluating the impact of treatment on the patients diabetic status. [0089] Efficacy parameters included Blood Glucose, HbA 1c and C-peptide levels (both fasting and meal-induced). These were measured on day 1, and at 1, 2, 3 and 6 months after initial treatment. In addition, antibody and lymphocyte parameters were assessed to investigate the impact of treatment on the patients immune system. These included antibody assays for autoantigens recognised as being involved in the autoimmune diabetes (GAD65, insulin, IA-2, and ICA), and lymphocytes potentially involved in the autoimmune process. These assays included FACS on whole blood for lymphocyte subsets, ELISPOT analysis of frozen polymorphonuclear cells from blood, and ELISA for serum cytokines. [0090] Immunoassays were performed on patient samples obtained from visits on day 1, and weeks 1, 4 (i.e. immediately pre-boost), 5 (i.e. 1 week post-boost), 8, and 24. These immunoassays will be performed at month 9 and 12 during the first 6 months of the 4.5 year study follow-up, and then for GAD Ab titre alone every 6 months for the remaining 4 years. [0091] Standard Haematology and Biochemistry analyses were performed at screening, day 1, and weeks 1, 2, 4, 8, 12 and 24. [0000] Clinical Safety [0092] There were no SAEs or deaths during the trial. There were 32/47 patients (68%) with 51 AEs. The majority of patients in each treatment group had at least one AE, most of which were due to influenza-like symptoms, with nasopharyngitis as the most common AE. [0000] Clinical Efficacy [0000] C-peptide at 6 Months, 12 Months and 18 Months: [0093] A 36% (p=0.008) increase in fasting and a 19% (p=0.0156) increase in meal-stimulated C-peptide levels at week 24 were seen in the 20 μg dose group. The increase in fasting C-peptide was significantly different compared to placebo (p=0.0011). The effect appeared to be maintained throughout the study period (18 months) No other statistically significant changes in C-peptide were seen in the other dose groups. [0094] The increase in fasting plasma C-peptide seen in the 20 μg dose group was also evident when the data were normalised for glucose and compared to either baseline (47% increase, p=0.0078) or placebo (p=0.0008). An increase in meal-stimulated C-peptide/glucose (24% increase, p=0.0391) compared to baseline was also observed within the 20 μg group. [0095] Patients given placebo or the 4 μg dose had almost identical plasma C-peptide/glucose ratio during the 24 weeks follow-up, inferring the absence of impact in the 4 μg dose group and supporting this as being defined a “no-effect” dose level. However, over the 18 months follow-up period a small gradual increase in the C-peptide/glucose ratio was seen. This was however not statistically significant. HbA 1c : [0096] A steady gradual increase in HbA 1c levels (p=0.01) was found in the placebo but not in the other dose-groups, inferring a reduction in glycemic control as diabetes progressed in untreated patients through the 18 months study period. A greater trend towards elevated HbA 1c levels was indicated for the placebo, 4 μg dose group, than for the 100 μg dose group, suggesting, in contrast, an improvement in glycemic control in patients receiving the latter dose level. In the 20 μg dose group in particular a decrease in HbA 1c levels was seen throughout the 18 month follow-up period indicating an improvement in glycemic control. [0097] The average rate of change in HbA 1c per month was statistically significant compared to placebo in the 20 μg dose group (P20 01 ) which was estimated by a linear mixed model assuming random intercepts and slopes. Mean Difference 95% Cl p-value Placebo group Reference 4 μg dose group −0.05 (−0.12, 0.03) 0.20 20 μg dose group −0.09 (−0.17, −0.02) <0.01 100 μg dose group −0.07 (−0.14, 0.00) 0.06 Rate of change per month compared to placebo group Impact on Patient Immune System: GAD65 Antibodies: [0098] No significant change in GAD65Ab levels (expressed as U/ml) was found in the placebo or 4 μg group. Levels in the 20 μg dose group did not change during the first 4 weeks, however, between 8 and 24 weeks 7/8 (88%) patients showed a decline. Similarly, in the 100 μg dose group there was a decline in 8/9 (89%) patients despite an increase in three of these patients between 4 and 24 weeks. All eight patients in the 500 μg group developed either an early increase before week 4 or a gradual increase after additional boost injections during the 24 weeks, and showed between a 2.1-fold and 22.1-fold maximum increase in GAD65Ab levels. Measurement of GAD65Ab is currently the most robust marker used to identify autoimmune diabetes and predict future insulin requirement in LADA. Their clear induction in the top dose group (p=0.001) support the impact of Diamyd™ treatment on the immune system. The decrease in GAD65Ab levels associated with efficacy at the 20 μg dose level may reflect a preservation of beta cells. This may be rationalized by reduced beta cell destruction lowering the amount of GAD65 released and presented to the immune system, resulting in reduced quantities of antibodies produced. A direct down-modulatory effect on B lymphocyte activity is also possible. [0000] T Lymphocytes: [0099] There were no differences between the groups in the majority of peripheral T lymphocyte subsets (CD3+, CD4+, CD8+, NK) analysed on day 1 and during the 24 weeks of observation. In contrast however, a statistically significant increase over time was found for the ratio of a particular T cell subset in patients receiving 20 μg Diamyd™ (p=0.012), and this increase was different from that in the placebo group (p=0.03). This T lymphocyte subset (with the surface markers CD4+ and CD25+) are currently implicated in regulating the activity of other T cells, and their involvement in inhibition of autoimmunity has also been demonstrated in animal models. [0100] A positive correlation between the change in this CD4 + CD25 + /CD4 + CD25 − T cell ratio and change in fasting C-peptide (r=0.51; p<0.005) was found, supporting the increase in C-peptide being related to an increase in this T cell ratio. This correlation was also found for meal-stimulated C-peptide (r=0.34; p<0.05). [0101] In view of the critical involvement of GAD65-specific T helper and cytotoxic T cells in the autoimmune destructive process leading to insulin dependence, positive evidence for the induction of a different T cell subset, capable of down-regulating autoimmunity, is considered to be an important study finding. CONCLUSIONS [0102] The foregoing study supports the following conclusions: [0103] Statistically significant increases in fasting and meal-stimulated C-peptide levels were apparent in the 20 μg dose, and these positive effects were confirmed when these data were normalised against fasting blood glucose. The positive effects was maintained throughout an 18 months follow up period. [0104] Positive evidence for immunomodulation was provided by analysis of T cell subsets. This strongly indicates that two injections of Diamyd™ effectively increases C-peptide production as a result of specific down regulation of beta cell inflammation by activated regulatory T cells. [0105] The Diamyd™ treatment raises no safety concerns. In particular, GAD65Ab levels, even after re-boosts at the top dose (4×500 μg), do not support the likelihood of Diamyd™ treatment causing neurological disease (e.g. Stiff Man). [0106] At two years, 7/14 patients in a control group (a “no-effect” 4 μg dose group +placebo) versus 1/8 of patients receiving the effective 20 μg dose became insulin dependent. [0107] Positive evidence for safety and efficacy together with the provision of insights into the mechanism of action of the treatment therefore strongly support the potential for Diamyd™ as a therapy for autoimmune diabetes. [0108] All publications and patents mentioned herein are hereby incorporated by reference to the same extent as if each individual publication or patent was specifically and individually indicated to be incorporated by reference. Related Provisional Patent Application Ser. No. 60/478,392 and the corresponding U.S. patent application based thereupon is also hereby incorporated herein by reference. Many variations of the present invention within the scope of the appended claims will be apparent to those skilled in the art once the principles described herein are understood. REFERENCES [0000] 1. Gepts W. Pathologic anatomy of the pancreas in juvenile diabetes mellitus. Diabetes 1965; 14:619-633. 2. Leslie R D, Atkinson M A, Notkins A L. Autoantigens IA-2 and GAD in Type I (insulin-dependent) diabetes. Diabetologia 1999; 42:3-14. 3. Verge C F, Gianani R, Kawasaki E, et al. Number of autoantibodies (against insulin, GAD or ICA512/IA2) rather than particular autoantibody specificities determine risk of type I diabetes. J Autoimmun 1996; 9:379-383. 4. Graham J, Hagopian W A, Kockum I, et al. Genetic effects on age-dependent onset and islet cell autoantibody markers in type 1 diabetes. Diabetes 2002; 51:1346-1355. 5. Zimmet P Z, Tuomi T, Mackay I R, et al. Latent autoimmune diabetes mellitus in adults (LADA): The role of antibodies to glutamic acid decarboxylase in diagnosis and prediction of insulin dependency. Diabetic Med 1994; 11:299-303. 6. Turner R, Stratton I, Horton V, et al. UKPDS 25: autoantibodies to islet-cell cytoplasm and glutamic acid decarboxylase for prediction of insulin requirement in type 2 diabetes. UK Prospective Diabetes Study (UKPDS). Lancet 1997; 350:1288-1293. 7. Tuomi T, Carlsson, A Li H, et al. Clinical and genetic characteristics of type 2 diabetes with and without GAD antibodies. Diabetes 1999; 48:150-157. 8. Kaufman D L, Clare-Salzler M, Tian J, et al. Spontaneous loss of T-cell tolerance to glutamic acid decarboxylase in murine insulin-dependent diabetes. Nature 1993; 366:69-72. 9. Tisch R, Yang X D, Singer S M, Liblau R S, Fugger L, McDevitt H O. Immune response to glutamic acid decarboxylase correlates with insulitis in non-obese diabetic mice. Nature 1993; 366:72-75. 10. Pleau J M, Fernandez-Saravia F, Esling A, Homo-Delarche F, Dardenne M. Prevention of autoimmune diabetes in nonobese diabetic female mice by treatment with recombinant glutamic acid decarboxylase (GAD65). Clin Immunol Immunopathol. 1995; 76: 90-95. 11. Petersen J S, Karlsen A E, Markholst H, Worsaae A, Dyrberg T, Michelsen B. Neonatal tolerization with glutamic acid decarboxylase but not with bovine serum albumin delays the onset of diabetes in NOD mice. Diabetes 1994; 43:1478-1484. 12. Tian J Atkinson M A, Clare-Salzler M, Herschenfeld A, Forsthuber T, Lehmann P V, Kaufman D L. Nasal administration of glutamate decarboxylase (GAD65) peptides induces Th2 responses and prevents murine insulin-dependent diabetes. J Exp Med 1996a; 183:1-7. 13. Tian J, Clare-Salzler M, Herschenfeld A, et al. Modulating autoimmune responses to GAD inhibits disease progression and prolongs islet graft survival in diabetes-prone mice. Nat Med. 1996b; 2:1348-1353. 14. Tisch R, Liblau R S, Yang X D, Liblau P, McDevitt H O. Induction of GAD65-specific regulatory T-cells inhibits ongoing autoimmune diabetes in nonobese diabetic mice. Diabetes 1998; 47:894-899. 15. Lethagen Å L, Ericsson U B, Hallengren B, Groop L, Tuomi T. Glutamic acid decarboxylase antibody positivity is associated with an impaired insulin response to glucose and arginine in nondiabetic patients with autoimmune thyroiditis. J Clin Endocrinol Metab 2002; 87:1177-1183. 16. Bingley P J, Bonifacio E, Mueller P W. Diabetes antibody standardization program: first assay proficiency evaluation. Diabetes 2003; 52:1128-1136. 17. Brown P, Rothwell J C, Marsden C D. The stiff leg syndrome. J Neurol Neurosurg Psychiatry. 1997; 62: 31-37. 18. Barker R A, Revesz T, Thom M, Marsden C D, Brown P. Review of 23 patients affected by the stiff man syndrome: clinical subdivision into stiff trunk (man) syndrome, stiff limb syndrome, and progressive encephalomyelitis with rigidity. J Neurol Neurosurg Psychiatry 1998; 65: 663-640. 19. Smith G E, Summers M D, Fraser M J. Production of human beta interferon in insect cells infected with baculovirus expression vector. Mol Cell Biol. 1983; 3:2156-2165. 20. Shevach E M. CD4+CD25+ suppressor T cells: more questions than answers. Nat Rev Immunol 2002; 2:389-400. 21. Sakaguchi S. Regulatory T cells: key controllers of immunologic self-tolerance. Cell 2000; 101:455-458. [0130] 22. Shevach E M, McHugh R S, Piccirillo CALIFORNIA, Thornton A M. Control of T-cell activation by CD4+CD25+ suppressor T cells. Immunol Rev 2001; 182:58-67. 23. Jonuleit H, Schmitt E, Stassen M, Tuettenberg A, Knop J, Enk A H. Identification and functional characterization of human CD4(+)Cd24(+) T cells with regulatory properties isolated from peripheral blood. J Exp Med 2001; 193:1285-1294. 24. Stephens L A, Moftet C, Mason D, Powrie F. Human CD4(+)CD25(+) thymocytes and peripheral T cells have immune suppressive activity in vitro. Eur J Immunol 2001; 31:1247-1254. [0133] The preferred embodiment herein disclosed is not intended to be exhaustive or to unnecessarily limit the scope of the invention. The preferred embodiments were chosen and described in order to explain the principles of the present invention so that others skilled in the art may practice the invention. Having shown and described preferred embodiments of the present invention, those skilled in the art will realize that many variations and modifications may be made to affect the described invention. Many of those variations and modifications will provide the same result and fall within the spirit of the invention. It is the intention, therefore, to limit the invention only as indicated by the scope of the claims.

The present invention regards methods and formulations for the treatment of diabetes and the prevention of autoimmune diabetes. The invention includes the administration of human recombinant GAD65 protein in a pharmaceutically acceptable adjuvant.

BACKGROUND OF THE INVENTION 1. Field of the Invention The subject invention relates generally to sharpeners for writing or drawing implements and, more specifically, to electric sharpeners for crayons. 2. The Prior Art Crayon or pencil sharpeners are common consumer products. Typically such devices are designed to be either portable or mounted to a surface in a fixed fashion. The configuration of conventional sharpeners provide a conical block with opposed walls defining an implement receiving channel. The walls provide sharpening edges, of either metallic or plastic composition, that extend from the base of the housing to its apex. The edges engage and shave the surface of the crayon or pencil as the implement is pressed into the opening and rotated. In regard specifically to crayon sharpeners, the crayon is inserted downward into the conical housing and rotated against the wall edges. The tip of the crayon, formed of wax, plastic, or similar material, is shaved layer by layer into a conical form, tapering to a point. The shavings pass through openings between the wall edges into a receptacle below that can be detached and emptied when full. Electric sharpeners are designed to rotate the cutting block while the user holds the writing implement stationary against the cutting edges. Representative of known sharpeners are the embodiments set forth in U.S. Pat. Nos. 2,857,881; 4,248,283; and 4,991,299. The cutting elements in each are of the type described above. The '881 embodiment is of note for showing a crayon carton that provides a sharpening element in one of the carton sidewalls. The shavings are collected within a separate internal compartment of the carton and emptied by opening one of the carton flaps. The state of the art sharpeners work well and are widely accepted by their users. However, several shortcomings are attendant their use, particularly in the sharpening of crayons. In order to appreciate the shortcomings it is important to note that crayons are coloring implements formed by a molding operation into a specific point configuration of plastic or wax, to provide a coloring tip of optimal utility. The form of the tip is frustroconical, tapering downward from a inwardly stepped annular shoulder to a flat circular nose. The flat nose, wider than a point, is more suitable for coloring than a point for it enables a wider band of color to be applied with each stroke. A paper or plastic sleeve is formed to encase the crayon and is either removed by hand prior to sharpening the point or removed by the sharpener during the sharpening procedure. The molded form of the tip created in the manufacture of the crayon is optimal for its intended use, but quickly deteriorates with use. The post manufacture sharpening of the crayon into a sharp point, as done with prior art sharpeners, however, creates a crayon tip that is inferior to that formed in the original mold. A sharp point will wear down quickly into all undesirable dull round shape. Moreover, a sharp point is much more inefficient in laying) a wide band of color with each stroke. In addition, the paper jacket surrounding the crayon is relatively abrasive to cut when compared to the soft crayon material. Repeated use of known sharpeners against such a jacket can cause plastic cutting blades of conventional sharpeners to dull quickly. Removing the sleeve by hand can eliminate this deficiency but is inconvenient from the user's standpoint. Another deficiency in available sharpeners, particularly electrically driven versions, is that they lack adequate user safeguards. Since the users of crayon sharpeners are young children, it is important to guard the user from contact with the cutting blades of the sharpener, both during the sharpening procedure and when the shavings receptacle is being emptied. Moreover, safeguards are needed to insure that young users will not damage the crayon sharpener by inserting into the cutting station inappropriate objects that are much harder than crayons, such as pencils or pens. Commercial sharpeners have blades that are relatively difficult to maintain or repair. Lastly, young users are more likely to use sharpeners in such a manner as to cause end portions of the crayon to break off in the cutting station. Available sharpeners neither deter such breakage nor facilitate easy removal of the broken pieces from the cutting station. SUMMARY OF THE INVENTION The subject invention overcomes the aforementioned shortcomings by providing a crayon sharpener that restores the crayon tip to its manufactured configuration, facilitates safe and convenient repair and maintenance but reduces the need therefor; and contains safety features that protect young users. In addition, the sharpener incorporates a built-in piece ejection pin for expelling broken crayon tips from the cutting station. The subject sharpener comprises a carry case having an internal storage compartment or storing crayons and other supplies, and a battery driven crayon sharpener built into one of he carry case sidewalls. The sharpener comprises a fixedly mounted battery and drive tear rain and a removable cartridge module. The cartridge module couples to the drive gear train in use and includes a cartridge block having four independently oriented cutting blades and a shaving collecting drawer therebeneath. The cartridge block has an axial bore therethrough dimensioned to receive a crayon and a pair of conically beveled plastic blades at an inward end of the bore positioned to contact a forward end of the inserted crayon. The motor drive train rotates the cartridge block, causing the plastic blades to impart a conical nose to the forward crayon end and to cut an instepped annular shoulder around the conically formed crayon tip. A preparatory steel blade is also provided, mounted to the cartridge block and oriented normal to the crayon axis and positioned to contact a forward peripheral surface of the canyon and score the jacket therearound. A secondary steel blade is mounted to the cartridge block and oriented parallel to the axis of the crayon. The secondary blade rotates with the block to peel off and remove the paper covering that was scored by the preparatory steel blade mounted normal to the crayon axis. An ejector pin is positioned to extend coaxially with the forward end of the cartridge block bore and provides a vertical forward surface that operates to form a flat vertical nose surface on the crayon tip during the sharpening procedure. Combined, the action of the blades and ejector pin forward surface restore the crayon tip to its original manufactured configuration. In addition, the ejector pin is spring loaded by insertion of the crayon into the cartridge block. Upon removal of the crayon the forward surface of the ejector pin moves into the cartridge block bore to dislodge any broken crayon pieces therein which thereupon fall down into the module drawer. Automatic motor engagement and disengagement responsive to insertion of the crayon is provided and the gear train driving the cartridge block is configured to disengage the drive whenever an article harder than a crayon such as a pencil or pen, is inserted into the cartridge bore. The motor also is disabled whenever the cartridge module is removed from the carry case sidewall. The cartridge module shaving drawer can be readily emptied through a side door and an internal flange within the drawer prevents the user from placing fingers in proximity to the cartridge block blades above the drawer. The blades, however, can be accessed if necessary when the cartridge module is disattached for repair or replacement of the blades. Accordingly it is an objective of the subject invention to provide a crayon sharpener that restores the forward tip of a worn crayon to its original configuration. A further objective is to provide a sharpener that self-ejects broken crayon pieces from the cutting station. Another objective is to provide a crayon sharpener that provides ready access to cutting blades for maintenance or replacement. An objective of the invention is to provide a crayon sharpener having automatic drive motor engagement and disengagement responsive to the presence of a crayon. An objective of the invention is to provide a crayon sharpener that automatically disables the drive motor when a harder implement such as a pen or pencil is inserted into the cutting station. Yet a further objective is to provide a crayon sharpener having cutting blades of respective material composition. A further objective is to provide a crayon sharpener having a removable module for blade access and for shavings disposal. Still a further objective is to provide a crayon sharpener that is made of relatively few parts and that requires a low level of maintenance. Another objective is to provide a crayon sharpener that is economically and readily produced, readily assembled and that is convenient to the user. These and other objectives, which will be apparent to those skilled in the art, are achieved by a preferred embodiment that is described in detail below and illustrated in the accompanying drawings. DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the assembled sharpener. FIG. 2 is an exploded perspective view of the carry case and motor housing. FIG. 3 is a right end elevation view of the assembled sharpener. FIG. 4 is a longitudinal section view through the sharpener taken along the line 4--4 of FIG. 3. FIG. 5 is an exploded perspective view of the module cover plate and retention cap. FIG. 6 is a planar inward end view of the cartridge module. FIG. 7 is a longitudinal section view of the cartridge module taken along the line 7--7 of FIG. 6. FIG. 8 is a planar outward end view of the cartridge module with the cover plate removed. FIG. 9 is an exploded perspective view of the ejector pin, drive housing, clutch collar, cartridge block, and motor controlling contacts. FIG. 10 is an exploded perspective view of the cartridge block and blades and a representative crayon. FIG. 11 is a top plan view of the assembled cartridge block. FIG. 12 is a transverse section view through the cartridge block, taken along the line 12--12 of FIG. 11. FIG. 13 is a transverse section view through the cartridge block, taken along the line 13--13 of FIG. 11. FIG. 14 is a transverse section view through the cartridge block, taken along the line 14--14 of FIG. 11. FIG. 15 is an exploded side elevation view of the cartridge block, clutch collar, and drive housing. FIG. 16 is a longitudinal section view through the assembly of FIG. 15, taken along the line 16--16. FIG. 17 is a longitudinal section view through the assembled drive housing. FIG. 18 is a plan view of the motor and drive train assembly. FIG. 19 is an exploded side elevation view of the drive housing, electrical motor contacts, and the cartridge housing, shown with the contacts in the disengaged position. FIG. 20 is an exploded side elevation view of the drive and cartridge housing shown with the electrical motor contacts in the engaged position. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring initially to FIGS. 1, 2, and 4, the subject sharpener assembly 10 is seen to comprise a lower housing 12, an upper housing 14, a lid 16, a handle 18, a cartridge module 20, a gear box housing 22, and a cover plate 24. The assembly 10 combines to form a hand carried portable crayon storage container having an integral battery powered crayon sharpener built therein. The four sided lower housing 12 is molded from conventional plastics material by conventional means, and is defined by sidewalls 26, 28, and end walls 30, 32 projecting from a bottom floor surface 29 to an upper rim 31. Extending upward from within the housing, proximate the four corners, are four assembly sockets 34, each having an upwardly opening axial bore 35. A series of three parallel spacer walls 36 project upward from the floor 29 include upwardly concave upper edges 37. A bottom opening battery compartment 38 extends into the floor 29 as shown. Formed within the end wall 30 at the top rim 31 is a semicircular pivot pin flange 40. Across from the flange 40, extending into the top rim 31 of the opposite end wall 32 is a semicircular opening 42. The upper housing 14 is a four sided plastic molded form, having sidewalls 44 and end walls 46, 48. A semi-circular pivot post flange 50 projects outward form end wall 46 and extending upwardly into the opposite end wall 48 is a semi-circular opening 52 (FIG. 5). The housing 14 further includes an inner storage compartment 54 and a raised platform at one end of the compartment 54 that is formed to provide adjacent crayon holding channels 56. A through-bore 58 exists through the vertical wall 55 of the raised platform as shown. The lid 16 is a concave body 60 formed from plastic by conventional means. The body 60 merges at opposite ends with raised shoulder portions 62, each having a handle socket recess 64 formed downward therein and a through slot 66 extending downwardly through the lid to an underside. The lid is configured to have an end flap portion 68 through which a circular hole 70 extends. The opposite lid side is formed having a larger end flap portion 72 through which a larger circular hole 74 extends. The handle 18 is an elongate plastic form having a central grip portion 76 of inverted U-shaped cross-section, defined by side surfaces 78. Four dependent rectangular retention tabs 80 extend from the side surfaces 78, each having a locking flange 82 at a lower free end. The components 12, 14, 16, 18, 20, 22, and 24 fit together to form the assembly shown in FIG. 1. The cartridge module and gear box housing 22 are cylindrical cans of plastic construction that are supported by the arcuate edges 37 of the lower housing support walls 36. So located, the locking cover 24 is adjacent the end wall 32. The upper housing attaches to the lower housing and includes like-shaped downwardly directed edges (not shown) that, with edges 37, encircle and entrap the components 20, 22. The upper housing further has dependent posts (not shown) that extend from an underside into the bores 35 of the support posts 34, whereby connecting the housings 12, 14 together. So joined, the flanges 40, 50 of the housings 12, 14 form a circular pivot post extending outward from on end of the assembly, and the openings (FIG. 5) 42, 52 of the housings 12, 14 at the opposite end form a circular opening that communicates with an internal chamber defined by the components 12, 14. The lid is pivotally connected to the upper housing 14 by the placement of flap through hole 70 around the pivot post formed by flanges 40, 50, and flap through hole 74 around the circular opening formed by the openings 42, 52. Pivotally mounted lid 16 encloses the storage compartment 54 of the upper housing 14, and moves along an arcuate path between open and shut conditions. The handle 18 snaps into the upper sockets 64 of the lid 16, as tabs 80 project downward through lid slots 66 and the locking flanges 82 catch over an underside edge of the slots 66. The handle call then be used to transport the container or to rotate the lid into an open position. With reference to FIGS. 2, 4, 5, and 7, it will be seen that the end flap 72 of the lid 16 is formed having an arcuate cutout channel 84 along the top perimeter hole 74. Intermediately positioned along the channel 84 is a rectangular notch 86. The notch 86 operates as a keyway for facilitating the removal of the cartridge module from the container as will be explained below. The lock cover 24 is of a concave dish shape, having a radiussed outer wall 88. A slot 90 projects rearward from the outer wall 88 at the top, and a lip 92 projects rearward from wall 88 at the bottom. Proximate the slot 90, a cylindrical sleeve 94 projects rearward and throughbore 96 projects through the sleeve 94 from an outward surface of the wall 88. A rectangular alignment tab 95 projects outward from the peripheral edge of wall 88 and includes a locking flange 97 at the remote end thereof. Finger depressions 98 extend into the outward facing surface of the wall 88 to facilitate manual grasping and turnings of the cover 24. Continuing, with reference to FIGS. 5, 6, 7, and 7, the subject crayon sharpening incorporates a removable cartridge module 100 that comprises a drawer housing 102, a pivotal drawer door 104, and a cartridge block 106. The drawer housing 102 is of plastic construction having an internal upper chamber 108 and a lower, shavings collection chamber 110, with chambers 108, 110 being separated by a horizontally extending, downwardly concave partition flange 112. The housing 102 has a forward wall interrupted by a forwardly projecting cylindrical sleeve 116 proximate a top end. The sleeve has forward ends 118 inwardly formed as shown. The cover 24 attaches to the housing 102 by two screws 119 as shown in FIG. 6 that fit into two counter bored bosses 117 (FIG. 8) on the drawer housing and into two screw bosses (not shown) in the rearward facing surface of cover 24. A pair of spaced apart cylindrical pivot pins 120 extend from the sides of the drawer housing into the lower chamber 110 thereof The door component 104 is of plastic construction, preferably transparent, and comprises a forward wall 122 and a bottom wall 124 connected at a right angle. The door has a pair of pivot post sockets 126, 128 formed and located to capture the pivot posts 120 therein, making the door reciprocally rotatable about the posts 120. A latch 130 of U-shape configuration is provided having a reversely formed upper free end 132 and a locking flange 134 extending thereacross. The latch flange 134 catches over the lower edge of drawer housing front surface 114 to lock the door component 104 in an upright condition, below the upper chamber 108. The door 104 can be freed to rotate clockwise by compressing the latch 130 sufficiently to enable free end and flange 132, 134 to clear the lower edge of the front wall 114. So freed, the door can rotate clockwise into an inverted condition, whereupon the shavings contents accumulated upon the door in an upright condition will be expelled. The phantom lines of FIG. 7 depict the inverted state. Thereafter, the door can be rotated counter clockwise until latch end 132 and flange 134 snap back over the lower end of wall 114. Thus, the drawer readily and conveniently can be emptied and returned to its original state. It will be appreciated that the cartridge module 100 shown in FIG. 7 is a self-contained assembly that is transportable by grasping the cover 24. Also, it will be noted that the cover 24 attaches to the outward edge of the housing 102 by means of two screws 119. A protrusion 135 of elongate cylindrical configuration and having a rounded remote end, extends rearward from the housing surface 114 through an aperture 137 in module housing 20 as will be appreciated from FIGS. 6, 19, and 20. The protrusion 135 functions to apply a biasing force to the motor actuating contacts as will be explained below. As seen from FIGS. 4, 7, 9, and 10, the cartridge block 106 seats lengthwise within the upper chamber 108 of the drawer housing 102. The block 106 comprises a cylindrical rearward sleeve 136 having conical outwardly projecting annular gear teeth 138 therearound and bore 140 therethrough; an intermediate larger diameter sleeve 142 adjoining the forward sleeve 136 and having a series of spaced apart retention ribs 144 therearound and extending lengthwise along the sleeve 136; and an outwardly directed semi-circular retention flange 146 at a forward edge of sleeve 136. Internally, the bore 140 terminates at an inward partition wall 148, and an aperture 150 that is coaxially aligned with the bore 140 proceeds through wall 148 to the forward side thereof. A cutting station generally referenced at 152 exists forward of partition wall 148. The cartridge block 106 includes a central planar surface 154 extending forward from the flange 146, through which a centrally disposed elongate opening 156 extends. Opposite sides of the opening 156 comprise cutting blade edges 158, 160 that converge from a forward end to a rearward end of the station 152. The central planar surface 154 is flanked on both sides by sidewalls 162,164, and extends forwardly to a vertical, semi-circular mounting flange 166. A blade supporting pedestal 168 is positioned upon the surface 154 in abutment with the flange 166. The flange 166 has three apertures 170, 172, and 174 therethrough and a fourth aperture 173 extends through the surface 154 to one side of the central opening 156. A forward cylindrical sleeve 176 extends from the flange 166 to a forward end of the cartridge block; the sleeve 176 having a coaxial bore 178 extending from the forward end of the cartridge block backward to the inner partition wall 148 as best seen in FIG. 7. The bore 178 has a rearward end portion that extends through the cutting station 152 and is of circular dimension in cross section, diametrically sized to closely admit a standard sized crayon. A secondary blade 180 is provided that flat, horizontally oriented body 182 and a beveled cutting edge 184 that projects into the bore 178 and is oriented offset from yet parallel to the major axis of the cartridge block bore 178. The blade body 182 has a central through aperture 186. A preparatory blade 188 is further provided that has a flat, vertically oriented square shaped body 190 and a lower cutting edge 192 that extends into the bore 178 and is oriented transverse to the major axis of the cartridge bore. The body 190 has a step 194 formed in a lower corner adjacent to the cutting edge 192 and a centrally disposed through aperture 195. A blade retainer 196 is provided having a flat elongate center portion 206; stepped end portions 198, 200, and central mounting apertures 202, 204 extending through portions 198, 200. A horizontal cantilever flange 208 extends forward from an upper edge of portion 206 and a horizontal cantilever flange 210 extends rearward from a lower edge of portion 200. Flange 210 has a downwardly formed free end 212. Four assembly eyelets 214 are provided, each having a circular head 216 and a central cylindrical shank projecting therefrom. Assembly of the blades to the cartridge block will be understood from FIGS. 10, 11, 13, and 14. The blade 180 is positioned upon the cartridge block surface 154 with the flat forward edge of the blade against the flange 166, the aperture 186 in alignment over the aperture 173, and the side facing edge of the blade 180 against the sidewall 164. So positioned, the cutting edge 184 projects into the axial bore and bevels outwardly therefrom toward the rear of the cartridge block surface 154. A forward portion of the cutting edge 184 projects forward beyond the forward end of the cutting edges 158, 160. The cutting edge 184 is parallel to and offset from the central axis of bore 178. One eyelet 214 is inserted through aligned apertures 186, 173 to secure the blade 180 to surface 154. The blade 188 is likewise assembled to surface 154, with the forward facing side of body 190 abutting the flange 166, step 194 brought to rest upon the support 168, and aperture 195 aligned over aperture 172. The lower cutting edge 192 depends into the upper portion of the axial bore and is oriented perpendicular to the axis of the axial bore. One eyelet 214 extends through apertures 195, 172 to secure blade 188 to surface 166. The blade retainer 196 provides means for attachment of the blades 180, 188 to the surface 154. The retainer 196 is positioned upon the surface 154 with the tab 212 inserted down into the eyelet 214 within apertures 186, 173, and retainer tab 208 projecting, through the aperture 172 of flange 166. At the opposite end of the retainer, center portion 206 overlaps the blade 188 and the flange 166, and apertures 202 and 170 are in alignment and receive one eyelet 214 to secure the retainer 196 to the cartridge block. The final eyelet is inserted through aligned apertures 204 of the retainer and 174 of the flange 166. The retainer and the eyelet serve as mutually redundant connections for attachment of the blades 180,188 to the cartridge block. Together, the retainer 196 and eyelets 214 ensure that the blades 180, 188 will not move through use from their intended positions on surface 154, 166. The assembled cartridge block, retainer, and blades, are received within the cartridge module 100 as will be appreciated from a combined consideration of FIGS. 7 and 10. The cartridge block 106 assembles from the forward end of the drawer housing 102, residing in the upper chamber 108 thereof. Upon insertion of the cartridge block 106, the intermediate sleeve 142 of the block 106 resides within the cylindrical socket 116 of housing 102, and the sleeve 136 projects from the rearward housing end 118 with clearance. It will be noted that the gear teeth 138 of sleeve 136 are spaced inward from the housing end 118 and that a circumferential gap exists about the block sleeve 136. The retention ribs 144 of block sleeve 142 extend into close proximity to the sidewalls of socket 116 and cannot clear the inwardly formed end 118 to thereby prevent the cartridge block from exiting the rearward end of the drawer housing 102. The cylinder sleeve 94 of the cover member 24 captures the forward sleeve 176 of the cartridge block 106 therein with nominal clearance as shown. Spanning, the upper chamber 108, the cartridge block is free at both ends and along its intermediary length to rotate about the longitudinal axis thereof. The bore 178 of the block 106 coaxially aligns with the bore 96 of the cover member 24. The distance between the forward end of the bore 178 and the inner partition wall 148 at the rearward end of the cutting station 152, and the diameter of the coaligned bores 96, 178 are designed to accommodate the axial receipt of a standard crayon therein. As depicted in FIG. 10, a crayon 220 of the type commonly used is manufactured by a molding process to include an inner cylindrical core of colored wax, plastic, or the like 222, an outer jacket 224 of paper or plastic, and a frustroconical nose 226 that terminates at a circular nose end surface 228. The crayon end surface 228 is ideally suited for coloring in that it applies a relatively wider band of color with each stroke that achievable with a sharpened point. Referring to FIGS. 4, 9, 15, 16, and 17, a clutch collar 230 is shown having a cylindrical body 232; a throughbore 234 extending through body 232; a pair of diametrically opposite peripheral arched flanges 236, 238; and a radiussed lobe projection 240 directed outward from each flange 236, 238. The internal surface of the body 232 includes an annular ring of gear teeth 242. A cylindrical drive housing 244 is configured having, a main body 246 and a frontal annular bore 248 extending inward into the body 246 to an internal partition wall 247. An annular rearward bore 249 is provided on the rearward side of wall 247 and extends rearward to a rearward end of body 246. An outwardly projecting annular flange 250 extends about body 246 proximate the forward end thereof. An axial sleeve 252 extends through the body 246, with a forward sleeve end 254 projecting beyond the forward end of body 246 and a rearward sleeve end 259 projects beyond the rearward end of the body 246. An aperture 256 extends through the forward sleeve end 254 and an axial through bore 258 extends through the sleeve 252 from the rearward end 259 to the forward end 254 and communicates with the aperture 256. A ring of internal annular gear teeth 260 circumscribe an inner wall of the housing 244 in the forward bore 248 and a ring of outward directed annular gear teeth 262 circumscribe the outer surface of the housing 244 proximate the rearward housing end. A circular ring 264 is positioned within the rearward bore 249, having a body 265 and a throughbore 266. The ring body 265 has an annular forward facing channel 268 adapted to receive and seat a helical compression spring 270 and to press the spring against the internal surface of chamber 249. An ejector pin 272 is shown to comprise a forward segment 274 terminating at a circular forward end surface 275; an annular retention collar 276 positioned axially rearward of the forward segment 274; an elongate main body segment 278 terminating at a rearward end 280. A helical compression spring 282 receives the rearward end 280 therethrough and is positioned against the forward collar 276. An end cap 284 having a central socket 286 receives the rearward end 280 of the ejector pin 272 therein to prevent separation of the spring 282 therefrom. Referring to FIGS. 2, 9 and 18, a motor 288 is mounted to the gear box housing 22 and lead 290 electrically connects the motor 288 to contact 300 and lead 292 goes from the motor to the battery compartment 38. Motor 288 is a conventional drive motor that is common in the industry and operates on 4 "AA" alkaline batteries that are stored and electrically connected with the compartment 38. The electric motor 288 drives a worm gear 294 that meshes with and drives a combination gear 296. The gear 296 in turn meshes with and drives a spur gear 298 that engages and drives the outward gear teeth 262 of the drive housing 244. The gear train described above thus mechanically rotates whenever the motor 288 is actuated and rotational movement of the drive housing 244 stops whenever the motor 288 is deactivated. The switching of motor 288 between the on and off modes occurs via two separate electrical contacts 300 and 302 that are positioned adjacent to one another but electrically isolated by an insulation spacer 304. Contact arm 300 is L-shaped and includes a mounting aperture 306 and a remote contact tip 308. The spacer 304 is likewise L-shaped and includes an aperture 310; and L-shaped contact arm 302 is provided with mounting aperture 312 and includes a remote contact end 314. The position of the contact arms relative to the drive housing 244 will be understood from FIGS. 9, 18, 19, and 20. The contact arm 302 is longer that the contact arm 300 and the remote end of arm 302 is positioned forward and adjacent to the peripheral flange 250 of the drive housing 244. The protrusion 135 of the drawer housing 102 projects from surface 114 through an aperture 137 in the cartridge housing 20 and presses against the contact 302, biasing the contact 302 against contact 300. Whenever the drive housing is in the rearwardly biased position, as shown in FIG. 20, the spring 270 is compressed, and the contact end 308 of contact arm 300 is in electrical contact with the contact arm 302 and a circuit is established therethrough which activates the drive motor 288. However, when in the forward, or released position, as depicted in FIG. 17 and 19, spring 270 will exert a forward force and move the drive housing 244 forward and flange 250 of the housing will contact and force the remote end 314 of contact 302 forward, whereby breaking electrical contact between the contacts 300, 302, and disabling the motor 288. The force exerted by housing 244 against contact end 314 causes end 314 to resiliently flex about the remote end of protrusion 135, breaking the connection with contact 300. As will be explained below, the housing 244 moves axially rearward responsive to a crayon inserted into the cartridge block to activate the motor and returns to a forward axial position in the absence of a crayon to deactivate the motor 288. With reference to FIGS. 4, 7, 9, and 17, the operation of the subject sharpener will be explained. The clutch collar 230 is coaxially seated within the drive housing 244, with the housing center sleeve 252 projecting through the clutch collar 230 and the inward gear teeth 260 of housing 244 meshing with the lobe projections 240 of the clutch collar. The gear teeth 262 of the housing 244 mesh with the drive gear train as described above. The housing 244 reciprocates axially along the ejector pin 272 between a forward position, shown in FIG. 17, in which compression the spring 270 is relaxed and exerts no biasing force on the housing 244, and a rearward position in which the compression spring 270 is compressed against the inward surface of housing 22. The cartridge block 106 is rotationally seated within the removable cartridge drawer assembly 100. As the assembly 100 is inserted into the cartridge module 20, the leading end of the cartridge block sleeve 136 enters into the clutch collar 230 and a leading portion of the cartridge block gear teeth 138 mesh with the internal gear teeth 242 of the clutch collar. The cartridge block 106 reciprocates axially along the major axis of the housing cylindrical socket 116 a small distance indicated in FIG. 7 at 316. Axial movement in the rearward direction is initiated when a crayon 220 is inserted axially into cartridge block bore 178 and a forward end of the crayon contacts sharpening, edges 158, 160. Pushing the crayon inward causes the cartridge block forward gear teeth 138 further into the clutch collar teeth 242 and pushes the drive housing 244 axially rearward. Rearward movement of housing 244 causes spring 270 to compress, the peripheral flange 250 to disengage from the motor contact arm 302, and the contacts 300 and 302 to re-engage. With the re-engagement of contacts 300 and 302, motor 288 is activated and begins rotation of the housing 244 through worm gear 294 combination gear 296, and spur gear 298. Rotation of housing 244 causes rotation of the clutch collar 230 as lobes 240 are rotationally driven by gear teeth 260. The rotation of clutch collar 230 in turn causes the cartridge block 106 to rotate about its longitudinal axis as clutch teeth 242 drive the cartridge block teeth 138. Rotation of the cartridge block 106 causes rotation of the sharpening blades 158, 160, 180, 188 relative to the forward nose of the crayon 220. The vertical blade 188 scores the circumference of outer jacket 224 proximate the forward end as it rotates and the horizontal blade 180 initiates a horizontal annular cut into the forward end of the crayon as it rotates, stripping away the outside crayon jacket back to the cut made by vertical blade 188. Contemporaneously, the rotating blades 158, 160, oriented to converge from front edge to rearward edge, carve the nose portion 226 into a conical form. The shavings resulting from the cutting blades fall between the blades 158, 160 into the upper drawer chamber 108, thence onto the downwardly concave flange 112, and thereafter fall off into the lower drawer chamber 110 and onto the lower door panel 124. The subject invention incorporates means for disabling the rotation of the cartridge block 106 whenever an article harder than a crayon, such as a pen or pencil, is inserted into the cartridge block bore by mistake. As will be appreciated from the configuration of the clutch collar lobes 240 and the drive housing internal gear teeth 260, shown in FIG. 18, rotation of the clutch collar by the drive housing will occur only at a relatively low torque loading level. A higher torque loading will cause the lobes 280 to slip over the housing gear teeth 260, preventing the rotation of the collar 230 and the cartridge block 106 therein. For example, if the cartridge block is loaded with a harder object such a pencil, a larger torque will be required to turn the blades 158, 160, 180, 188 against the object. However, the torque required to rotate the cartridge block 106 will exceed the preset torque limits designed into the clutch collar lobes 240 and rotation of the clutch collar and cartridge block will be inhibited. Thus, the subject sharpener incorporates a fail-safe mechanism for disabling the rotation of the sharpening blades against an object that is harder than the relatively soft crayon for which the sharpener was designed. Removal of the crayon after it has been sharpened from the cartridge block releases earward pressure on the cartridge block 106 and drive housing 244, freeing spring 270 to direct a forward force on the housing 244 and cartridge block 106. Forward movement of housing 244 causes flange 250 to re-enrage motor contact arm 302, separating it from contact arm 300, whereby breaking the motor circuit and deactivating the motor. Consequently, rotation of housing 244 terminates and with rotation of the cartridge block 106. Insertion of a crayon into the cartridge block 106 thus initiates rotation of the cartridge block by engaging the motor 288 and withdrawal of the crayon terminates the rotation of the cartridge block 106 by electrically breaking the circuit of the motor 288. The contact between contacts 300 and 302 is also broken by the removal of the shavings drawer assembly 100 from the sharpener housings. As the assembly is withdrawn, the spring 270 causes the drive housing 244 to move axially forward, causing peripheral flange 250 to engage contact 302 and break electrical engagement between contact 302 and 300, whereby disabling the motor 288. Thus, removal of the drawer assembly 100 effectively disables the drive motor and prevents actuation of the drive assembly during its absence. The manner of removal of the drawer assembly 100 will be appreciated from consideration of FIGS. 5 and 6. The cover 24 of the drawer assembly 100 is provided with the lock tab 95, located at approximately the ten o'clock position. The lid 16 of the sharpener has a channel 84 formed in a peripheral edge of the opening 74, and a notch 86 is located within the channel at the twelve o'clock position. In order to remove the drawer assembly 100, the lid 16 must be rotated until the notch 86 aligns with the cover member tab 95, whereupon the cover member 24 and the drawer assembly 100 may be pulled out of engagement with the sharpener case. Replacement of the drawer assembly occurs in reverse sequence. That is, the lid 16 must be rotated so that the notch 86 is in the ten o'clock position so that the drawer assembly cover tab 95 can be inserted therethrough. The lid 16 is thereafter rotated into an upright position and tab 95 is trapped against the inside surface of channel 84. The removal of the drawer assembly 100 most frequently is for the emptying of shavings from the lower housing chamber 110. To effectuate removal, the latch end 132 is pushed down and in, causing the flange 134 to clear the lower end of wall 114. The lower door 104 can thereafter be rotated clockwise into an inverted position and its shavings contents emptied. It will be noted that with the door 104 open, the blade area of the cartridge block is digitally inaccessible because of the presence of flange 112. A child, therefore, cannot reach into the blade area and inadvertently be injured. A second reason for removal of the drawer assembly 100 is to replace the blades 158, 160, 180, or 188. Also, if the forward end of the crayon breaks off during the sharpening procedure and cannot be dislodged by the ejector pin as explained below, the cartridge block can be accessed by removal of the drawer face 114 by the loosening of two captive screws (not shown) and freeing the cartridge assembly for replacement or cleaning. The ejector pin 272 as seen in FIGS. 4, 7, and 9, extends through sleeve 252 of the drive housing 244 and the forward pin segment 274 projects through the aperture 256 in the sleeve end wall 254. The spring 282 is received over the ejector pin segment 278, and abuts the annular collar 276 at a forward end, and seats within an annular channel 318 at a rearward end. The rearward end 280 of the ejector pin projects through the through bore 58 within the wall 55 of the upper housing 14 and has end cap 284 secured thereover. As such, the end 280 of the ejector pin is digitally accessible from the storage compartment 54 of the upper housing 14. The forward end 274 of the pin 272 extends through the sleeve end wall 254 and through the inner partition wall 148 of the cartridge block as shown in FIGS. 7,9, 16, and 17. The forward circular end surface 275 of the pin 272 projects through end wall aperture 255 and into the cutting station 152. As the crayon is inserted into the cutting station 152 and is sharpened, the forward nose surface of the crayon will abut the forward end surface 275 of the pin 272 and take a circular form. The ejector pin 272 will be pushed by the crayon axially rearward, compressing the spring 282. After the sharpened crayon is removed, the spring 282 will force the pin 272 forward end surface 275 will push any residual crayon shavings or any small broken crayon pieces from cutting station 152 and they will drop out. If the pieces lodged in the cutting station 152 are of a larger size, the ejector pin may be forced axially forward by digitally pressing the rearward end 280 of the pin forward from within the storage compartment 54 of the upper housing 14. If that proves unsuccessful, the drawer assembly 100 can be removed and the cartridge block accessed and serviced. From the foregoing it will be appreciated that the subject invention functions to restore the forward tip of a crayon to its manufactured state. The outer jacket of the crayon is scored by the vertical blade 188, referred to as the preparatory blade, and the horizontal blade 180 lifts the paper and peels it away and in so doing cuts an annular shoulder 223 into the forward end. The convergent blades 158, 160 form a conical nose to the crayon and elector pin forward end surface 275 gives the crayon tip a circular flat nose end surface that is optimal for coloring purposes. The blades 180, 188 are formed of steel for durability since repeated cutting through the jackets of crayons can dull plastic blades. The blades 158, 160 are of plastic construction since they encounter only soft core material. The safeguards incorporated in the subject invention are apparent from the forgoing. First, the motor will be automatically engaged when the crayon is inserted into the cartridge block and therethrough forces the drive housing rearward. Removal of the crayon causes the motor to automatically disengage in reverse manner. Secondly, the insertion of a harder object, such as a pen or pencil, into the cartridge bore will cause the clutch collar to slip out of meshing engagement with the drive housing, whereby preventing the cartridge block blades from rotating against the harder object. The softer crayon, however, will not cause such slippage and the clutch collar will remain in engagement with the drive housing and be rotated thereby. Thirdly, the subject motor is disabled by the removal of the drawer assembly 100, an additional safeguard. The drawer assembly further facilitates easy removal of shavings through a bottom dropping door and incorporates an internal flange to render the cartridge block blades inaccessible to fingers when the bottom door is open. Lastly, the subject invention incorporates a self-ejecting pin for dislodging broken crayon pieces from the cutting station. While the preferred embodiment of the subject invention has been described above, the invention is not intended to be limited thereto. Other embodiments that will be apparent to those skilled in the art and which utilize the teachings herein set forth, are intended to be within the scope and spirit of the subject invention.

A crayon sharpening assembly is disclosed comprising an axially rotating cartridge block (106) having an axial bore (178) for axial receipt of a crayon with a forward end of the crayon positioned within a cutting station (152). A pair of convergent sharpening blades (158, 160) carve a conical nose into the forward crayon end; a secondary horizontal blade (180) engages the forward crayon end and cuts an annular stepped shoulder surrounding the conical nose; and a preparatory vertical blade (188) makes a vertical circumscribing cut through the jacket of the crayon proximate the forward end, whereby restoring the forward crayon end into its manufactured form. A carrying case (12, 14) is provided having a pivotal lid (16), with the sharpener drive assembly (20, 22) built into one end wall. A drawer assembly (100) is removable from the end wall and contains the cartridge block (106) and a housing (102) for collecting shavings generated in the sharpening procedure. A bottom housing door (104) opens to allow expulsion of the shavings. Rotation of the cartridge block (106) is facilitated by an electrically driven drive assembly that is automatically engaged and disengaged by the respective insertion and removal of the crayon and disengaged by the removal of the drawer housing assembly. Rotation of the cartridge block (106) is defeated by a clutch member (230) whenever an article that has a hardness greater than that of a crayon is inserted into the cartridge block cutting station (152).

FIELD OF THE INVENTION [0001] The present invention pertains to the field of the food industry, in particular it relates to those useful processes for preparing concentrated foaming compositions, preferably compositions of drinks sweetened with honey and such compositions. [0002] The present invention is also related to the cosmetic, pharmaceutical, and biochemical industries where these compositions can be employed. PREVIOUS ART [0003] In the previous art there are various documents that refer to the use of coffee and honey together for different purposes. [0004] The application US2003129267 (A1) discloses a Kona coffee and 100% pure honey based skin cleansing product that is applied as a facial mask and helps to smooth and soften the skin. This document is linked to the cosmetic industry and proposes the use of 2 raw materials: insoluble coffee beans and heated honey. [0005] The document CN102028071 (A) refers to honey to which starch, dextrin, cellulose and other binders are added. The preparation thus obtained is dehydrated by food additives. It is combined with coffee, tea, and other flavoring substances. The end result is a solid drink At least 8 raw materials are used, including some food additives (binders, gelling agents or thickeners and flavoring substance). In the mixing process mechanical intervention is not mentioned, nor is the way in which the coffee is combined in the preparation, which at the end a solid drink is obtained. There is no concrete information about its consistency. [0006] The publication AR041612 (A1) refers to a mix of pure honey with strawberry, pineapple, banana, green apple, orange, lemon, vanilla, coffee, chocolate and butter flavors. These are added in a greater or lesser degree according to the required flavor. This is mixed until a uniform mass is obtained. Here 2 raw materials are used and the result of the process is a uniform mass of flavored honey. [0007] The document GT198400028 (A) discloses a product that can be whipped to form mousse. Here multiple raw materials are used, among those, some food additives. The process is relatively simple and the result thereof is a solid storable product that can be turned into mousse. The base of the product is fat, binder and emulsifier, and it contains sugar or another natural or artificial sweetener plus additional flavorings. [0008] The application ES212322 (A1) refers to the preparation of coffee with liquid milk. The raw materials are mixed; namely whole natural cow or sheep's milk as a base, roasted natural coffee, sugar or honey, and salt. The mixture is then heated. To the thus obtained mass is added rennet and is fermented. The product is stirred until the curd is separated from the whey. Then, the solid mass is separated, dried and then taken to mature. The end result is a solid fermented product similar in consistency to semi-soft cheese. 5 raw materials are used in a very complex process: raw materials are subject to mixing, stirring, cooking, fermentation, drying, and maturation. The end result is a coffee with milk in a solid semi-soft block. [0009] None of the documents mentioned provide for a manufacturing method to make concentrated foaming compositions, preferably compositions to make drinks in the form of a dense consistent and stable product, which is used to make coffee, coffee with milk, or foaming milk by adding preferably hot water, without the necessity of beating. Such concentrated compositions are stable and can be used to fill sandwich cookies, cakes, or chocolates. SUMMARY OF THE PRESENT INVENTION [0010] It is therefore the purpose of this application, a process to prepare concentrated foaming compositions sweetened with honey, that consists of: [0000] a) provision and weighing the necessary quantities of raw materials to be used. b) provision of pure honey in a mixer and whipped at about 250 rpm to 1,500 rpm for about 5 to 30 minutes. c) adding at least one raw material selected from soluble coffee, powdered milk and honey to the mixed honey from step b) while it is being mixed, and d) once the desired consistency is achieved, divide the composition obtained in step c) into containers for distribution and marketing. [0011] Additionally, a stabilizer is incorporated together with the raw material in step c). [0012] Still further, chocolate in the form of cocoa powder, spices, natural flavors, alcohol, or natural alcohol flavors are added after step c) while it is still being mixed. [0013] Alternatively, the milk used may be condensed or evaporated. [0014] Preferably, the stabilizer used in the compositions is natural. [0015] Said stabilizer is selected from the group consisting of carob gum (gum from carob seeds) guar gum, tragacanth gum, Arabic gum, xanthan gum, karaya gum, tara gum, gellan gum, pectins, pectin, amidated pectin, cellulose, cellulose powder, microcrystalline cellulose, modified celluloses such as methylcellulose, ethlycellulose, carboxymethylcellulose, and mixtures thereof. [0016] Moreover, the spices are ground and selected from the group consisting of: anise, saffron, cardamom, cinnamon, juniper, ginger, nutmeg, vanilla, and mixtures thereof. [0017] Additionally, natural essences are selected from the group consisting of almond, hazelnut, orange, vanilla, and mixtures thereof. [0018] Also, the alcohol or natural alcohol essences are selected from the group consisting of rum, vodka, whiskey, whiskey cream, limoncello, amaretto, gin, triple-sec (Cointreau), cognac, grappa, and mixtures thereof. [0019] Another object of the present invention, a composition to prepare foaming coffee sweetened with honey obtained through the described process, consists of: 70% to 85% pure honey, and 10% to 30% soluble coffee, where the % are expressed as weight to weight %. [0022] Yet another objective of the present invention, a composition for preparing foaming coffee with milk sweetened with honey obtained by the described process, consists of: [0023] 70% to 85% pure honey, [0024] 10% to 25% soluble coffee, and [0025] 5% to 15% powdered milk, [0000] where the % are expressed as weight to weight %. [0026] Yet another objective of the present invention, a composition for preparing foaming milk sweetened with honey obtained by the described process, consists of: [0027] 70% to 85% pure honey, [0028] 15% to 30% powdered milk, [0000] where the % are expressed as weight to weight %. [0029] The described compositions also have a stabilizer. [0030] Still further, the composition consists of chocolate in the form of cocoa powder, spices, natural essences, alcohol, or natural alcohol essences, and mixtures thereof. [0031] Alternatively, the milk can be condensed or evaporated. [0032] Preferably, the stabilizer present in the compositions is natural. [0033] The stabilizer is selected from the group consisting of carob gum (gum from carob seeds) guar gum, tragacanth gum, Arabic gum, xanthan gum, karaya gum, tara gum, gellan gum, pectins, pectin, amidated pectin, cellulose, cellulose powder, microcrystalline cellulose, modified celluloses such as methylcellulose, ethlycellulose, carboxymethylcellulose, carboxyethylcellulose, hydroxyprpylcellulose, hydroxypropylmethylcellulose, ethyl methylcellulose, and mixtures thereof. [0034] Moreover, the spices are ground and selected from the group consisting of: anise, saffron, cardamom, cinnamon, juniper, ginger, nutmeg, vanilla, cloves, and mixtures thereof. [0035] Additionally, natural essences are selected from the group consisting of almond, hazelnut, orange, vanilla, and mixtures thereof. [0036] Also, the alcohol or natural alcohol flavor essences of are selected from the group consisting of rum, whiskey, whiskey cream, vodka, limoncello, amaretto, gin, triple-sec (Cointreau), cognac, grappa, and mixtures thereof. [0037] Preferably, the stabilizer is present from 0.1% to 3% per weight of the composition. [0038] Also preferably, the spices are present from 0.1% to 1.5% per weight of the composition. [0039] In its preferred that the natural essences be present from 0.01% to 0.05% per weight of the composition. [0040] Also in its preferred form, the alcohol, or natural alcohol flavor essences of are present from 0.01% to 0.5% per weight of the composition. [0041] Meanwhile, the chocolate in form of cocoa powder is present from 1% to 3% per weight of the composition. [0042] The condensed or evaporated milk is present from 2.5% to 8% per weight of the composition. [0043] The shelf life of the compositions ranges from at least 6 months to approximately two years. [0044] Lastly, the described compositions are for obtaining foaming coffee sweetened with honey or foaming coffee with milk sweetened with honey, or for foaming milk sweetened with honey by adding hot water. BRIEF DESCRIPTION OF THE FIGURES [0045] FIG. 1 shows the inside of the mixer with the whipping accessory in contact with concentrated composition of foaming coffee sweetened with honey. This mixer is used to put into practice the process of the present invention. [0046] FIG. 2 shows the appearance of a concentrated composition of foaming coffee sweetened with honey in a jar, obtained by the process according to the preferred aspect of the present invention. [0047] FIG. 3 shows the dense and stable consistency of the concentrated composition of foaming coffee sweetened with honey of FIG. 2 prepared by the process according to the preferred aspect of the present invention. [0048] FIG. 4 shows a cup of coffee with foam prepared with a concentrated composition of foaming coffee sweetened with honey (Composition 1.a) obtained according to the preferred method of the process of the present invention without additives or stabilizers. [0049] FIG. 5 shows a cup of coffee with foam prepared with a concentrated composition of foaming coffee sweetened with honey (Composition 4) obtained according to the preferred method of the process of the present invention with a natural stabilizer. [0050] FIG. 6 shows a cup of coffee with milk with foam prepared with a concentrated composition of foaming coffee sweetened with honey (Composition 5) obtained according to the preferred method of the process of the present invention with a natural stabilizer. [0051] FIG. 7 shows a cup of milk with foam prepared with a concentrated composition of foaming coffee sweetened with honey (Composition 20) obtained according to the preferred method of the process of the present invention with a natural stabilizer. DETAILED DESCRIPTION OF THE INVENTION [0052] The present invention consists of the manufacturing method for a new food product preferably with a base of coffee and/or milk sweetened with honey. It is healthier, foaming, instant, of practical usage, and has multiple applications. [0053] The particular characteristics of this product effectually permit it to be used mainly in the food industry, making it possible to utilize it for various purposes and applications in other categories of the same industry. [0054] This product can also be used as a base for use in other industries such as cosmetics, pharmaceuticals, and biochemistry. [0055] The innovative and inventive activity characteristics of the manufacturing process of the products described here, concentrated foaming compositions, preferably compositions to prepare, coffee, coffee with milk, and foaming milk sweetened with honey, respond to two surprising effects obtained unexpectedly during the implementation of this process: [0056] a) the unexpected capacity for honey to contain and maintain the air bubbles incorporated during this process for a long time, transforming the raw materials used in the concentrated foaming composition; and [0057] b) the yield of the final products obtained show an increase of between 40% and 70% in the original volume of the raw materials used. [0058] It is known in the art that the bubbles formed during the handling of honey, one of the raw materials used as a principal material base here, are eliminated, when the honey is left to rest for the necessary time. The present bubbles gradually move within the mass of honey until they reach the surface and are eliminated. [0059] During the manufacturing process here described, a great quantity of bubbles are incorporated in such a way that said displacement is stopped in such a way that they do not move within the mass of the final product, and are not eliminated. This makes the product stable enough to give it a shelf life of at least six months up to around 2 years, or more, preferably on the order of a year to a year and a half. In this way, the product can be conserved maintaining its properties, principally that of providing foam by adding water, preferably hot or very hot, without the necessity of whipping, which is common for these types of preparations. The foam achieved in this way is stable and consistent, providing a practically instant beverage. [0060] The processes for handling honey described below show demonstrably that since prior to 1959 up to the present day, have not changed, and because of that, honey has been processed and marketed in basically three ways: filtered/liquid, crystallized/solid, and creamy. [0061] Comparison between traditional processes and the mentioned ways of marketing honey regarding the proposed procedure here for the production of concentrated foaming compositions sweetened with honey, and such compositions can highlight two fundamental distinctive observations. [0062] a) As for the presence of air bubbles: [0063] Both producers and processors have worked and are working with honey nowadays with some incorporation of technology to a greater or lesser degree, or completely without, but the process always ends with a last or second to last stage of decantation or second filtration in decanter tanks in maturation holdings. [0064] Decanting is carried out for a period of time ranging from 2 or 3 days to a month or more. This is considered necessary since with this the density of the air bubbles hidden in the honey are eliminated, along with impurities that were left from previous stages. [0065] It's true that honey has the distinctive characteristic of “containing” hidden air bubbles in it during its handling, which can be removed by decantation. This means that with adequate resting time, the bubbles rise to the surface, break and disappear, but that they can not be “maintained.” That is, honey can not accommodate these bubbles without them being altered or disappearing during the resting stage. This quality is modified by way of preparing and presenting “foam,” which can be achieved through the application of a preferred way of preparing the product process here proposed. [0066] b) As for the type or form of preparation and commercial presentation of the obtained by the product process applied by this here proposed: [0067] The usual way that honey products are presented on the market are as “liquid or filtered honey,” “creamy honey,” or “crystallized honey.” [0068] To this day, a honey processed in the production process like the one of the present invention here proposed has not been presented. This process combines raw materials in concentrated foaming compositions. This product thus elaborated ceases to have the typical physical-chemical composition of honey, to become new foaming compositions which is a sine qua non that air bubbles are incorporated by intense whipping. [0069] Therefore, the application of this procedure as detailed below, not covered so far, results in a stable product in a new commercial presentation of honey as “foaming.” This gives the honey presented in this way the quality of maintaining and containing the air bubbles incorporated in the long term, giving it the particular characteristic of transforming into a “foaming” product which is instant, creamy, and of practical usage. [0070] Obtaining a versatile product based on natural ingredients was sought for the following reasons: [0071] 1) For its beneficial health implications. The main objective is to offer the consumer a food product developed and sweetened with excellent raw materials: pure honey with unique characteristics which make it naturally healthier; soluble coffee, preferably unroasted, powdered milk, or a mix of both. This objective justifies further application in multiple categories of the food industry. [0072] By “pure honey” we refer to the sweet and viscous fluid produced by honey bees as their main product. They make this from nectar collected mainly from flowers. Being a natural product, it is free from contaminants and/or additives of any kind. The bees collect, transform and combine the nectar with the invertase enzyme contained in their saliva. They then store it in the honeycombs where it matures, transforming it from a thin and perishable liquid substance to a stable high-carbohydrate substance. The physical chemical and organoleptic properties of honey are determined by the type of nectar the bees collect. The botanical origin of the plants used for honey also make it harder or easier to crystallize. [0073] By “soluble” or instantaneous coffee, we refer to a product obtained by a process in which the soluble solids are extracted from the roasted and ground coffee by an operation of solid-liquid extraction. The solvent water is partially evaporated and the subsequently removed using a drying spray (the extract is atomized in a drying chamber where it is put into contact with hot air) or lyophilization (the extract is frozen at low temperatures and is later submerged in water at low pressure) to achieve a powdered or granulated product capable of rapidly dissolving in water for consumption. [0074] By “powdered milk” or dehydrated milk we refer to the product obtained by dehydrating pasteurized milk. This is done in atomization towers where the water present in the milk is evaporated, obtaining a yellowish white powder which contains the natural properties of the milk. To turn it into a liquid state before drinking it, the powder should be dissolved in drinking water. This product is important because it does not have to kept cold, elongating its shelf life. [0075] By “natural stabilizer” we refer to any accepted and commonly used product used as a stabilizer in the food industry. It is from a natural source, or at least comes from a natural source and was chemically or enzymatically modified. With this clarification, it should be understood that “stabilizer” and “natural stabilizer” are used interchangeably here. However for the purposes of the present invention those stabilizers which are naturally occurring without chemical modifications of any kind are preferred. The person skilled in the art will perfectly know how to distinguish one from another considering this definition. The stabilizer provides stability for the foam and stability against temperature changes that the product could be exposed to. Without intending this to be considered limiting, and any stabilizer can be used, the preferred stabilizers are in the group consisting of carob gum (gum from carob seeds) guar gum, tragacanth gum, Arabic gum, xanthan gum, karaya gum, tara gum, gellan gum, pectins, pectin, amidated pectin, cellulose, cellulose powder, microcrystalline cellulose, modified celluloses such as methylcellulose, ethlycellulose, carboxymethylcellulose, carboxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, ethyl methylcellulose, and mixtures thereof, [0076] 2) For the exclusive characteristics of raw honey. The product obtained by the process of the present invention is specially made with pure honey. An identical or similar product with these singular characteristics and health benefits could not be achieved if it were replaced by any other sweetener. For example, any honey that is diluted or adulterated with other products that are not bee products, such as any kind of sugar would not be acceptable. [0077] 3) It allows the consumer to taste a product that, because of its manufacturing process is already sweetened, at its ideal point. It has foam without requiring this to be done manually and separately. Also, because of its particular characteristics in its consistency, it is of practical usage and allows for multiple applications. [0078] Therefore, the object of the present invention is a process for the manufacturing of a concentrated foaming composition sweetened with honey to prepare coffee, late, or foamy milk, ready to consume and for the products obtained in the same way. The obtained compositions are coffee or milk based food products sweetened with honey, healthier, foaming, of instant preparation, of practical usage, and with multiple applications. [0079] The first stage of manufacturing of the food products of the present invention, compositions to prepare coffee, coffee with milk, and foaming milk sweetened with honey, consists of the selection of the raw materials, that in its base formula, are pure honey, soluble coffee and/or powdered milk. [0080] For example, the preparation of a concentrated coffee, coffee with milk, or foaming milk composition requires the application of a production process that involves: [0081] a) Selecting the materials and raw materials needed, and dividing their proportions according to the variables to prepare, according to the components and parameters established in the section corresponding to the formulations. [0082] b) Placing the raw materials in a properly conditioned container to start the production process. It should be noted that, given the yield you get from this product, the containers used should hold approximately at least 50% more volume to contain the increase in volume generated in the process. [0083] c) Submitting the honey with the soluble coffee, powdered milk, or soluble coffee and powdered milk to a process of mechanical mixing and aerating. This is the same whether or not other ingredients are added. [0084] d) This production process should be applied to the raw materials, in proportions indicated in the corresponding composition, at a beating power of medium/high for the raw materials to be whipped and aerated with a beater from about 250 rpm to 1,500 rpm, and for 5 to 30 minutes. That is, for enough time to obtain a desired consistency as to achieve a shelf life on the order of at least about six months to about two years. [0085] During the whipping of the raw materials of the composition to be prepared, the product should not exceed 35° C., and more preferably 30° C. And during the dividing and packaging process, the obtained product should be in the best state between approximately 24° C. and 27° C. [0086] Thus, the mentioned raw materials are transformed, becoming a new product: a concentrated foaming composition, airy, and creamy, of a consistency highly superior to mousse. It can be used to make foamy honey sweetened coffee, foamy honey sweetened coffee with milk, or foamy honey sweetened milk by adding hot water. [0087] e) For example, with the application of the production process, a quantity of 1 kg of raw material, whipped for a period indicated in point (d), an incremental yield of between 40% and 70% compared to the original volume of the raw materials used is achieved. That is, approximately 1,400 cm 3 to 1,700 cm 3 of a concentrated foaming final product. [0088] The principal process variables of the process, rpm, and stirring time can be selected according to the characteristics of the desired final product, the machinery used, and the volume of the mixture of the raw materials used. In this way, and according to circumstances, more rpm needs less time to achieve the same result achieved with less rpm and more stirring or beating time. [0089] The concentrated foaming composition to prepare foaming coffee sweetened with honey or coffee with foaming milk sweetened with honey, or foaming milk sweetened with honey obtained with the process proposed here is not as yet typified in the Argentine Food Code, or in other equivalents documents of the same or similar importance with specific name that identifies it. [0090] Nor was it found in the various markets that sell food products of this type, any identical or similar products. [0091] The name foaming coffee, foaming coffee with milk, or foaming milk is directly related to 2 important considerations: [0092] 1) To the particular mechanical whipping and aeration process applied to the combination of raw materials used according to the type of product. The process makes it possible to obtain the composition for preparing foaming coffee sweetened with honey or coffee with foaming milk sweetened with honey, or for foaming milk sweetened with honey by providing such a quantity of air bubbles that they transform the utilized raw materials into a new product, with a base of coffee, coffee with milk, or foaming and aerated milk, with a consistency far superior to mousse, since the bubbles are contained and maintain in the product in the long term, from around approximately 6 months to 24 months, without it suffering alterations over time. Additionally, it preserves a delicate balance between the taste and body of the coffee, milk or mixture of the two, with the sweet aroma of the honey. [0093] 2) The air bubbles formed at the time of preparing the composition to prepare the foaming coffee sweetened with honey or coffee with foaming milk sweetened with honey, or for foaming milk sweetened with honey are distributed throughout the product evenly. They do not bind together or get lost. Thus, once prepared, only some of the bubbles, those that are in contact with the interior of the container, rise slowly to the surface, without changing the consistency of the end result in the interior of the composition to prepare foaming coffee sweetened with honey or coffee with foaming milk sweetened with honey, or for foaming milk sweetened with honey, just like the bubbles in fine sparkling wines do. Approximately not less than about 95% of the bubbles are contained and maintained thanks to the transformation undertaken by the raw materials used, generated with the application of the production process described here before. Raw Materials Used According to Type of Composition: According to the Formula Base and Variants [0094] The composition to prepare a foaming coffee sweetened with honey may be presented with, but is not limited to, the following varieties of flavors, although they: Original flavor (coffee and honey) with or without natural stabilizer With cinnamon (coffee, honey, and cinnamon) With cinnamon and chocolate (coffee, honey, cinnamon, and chocolate) With spices (various ground spices, such as anise, saffron, cardamom, cinnamon, juniper, ginger, nutmeg, vanilla, cloves, etc.) With powdered milk With condensed or evaporated milk With alcohol or natural essences or different alcohol flavors (such as rum, whiskey, whiskey cream, vodka, limoncello, gin, coffee liqueur, créme de cacao, amaretto, triple-sec (Cointreau), cognac, grappa, etc.) With natural essences of different flavors (almond, hazelnut, orange, vanilla, etc.) Examples of Compositions [0103] The following compositions are examples of how to best implement the present invention, but should not be considered limiting. Thus, variants of these compositions should be considered as falling within the scope of the present invention. [0000] COMPOSITION 1: This is a composition for preparing foaming coffee sweetened with honey or original flavor foaming honey coffee of mild or strong intensity. [0104] The original formula also supports all flavors that are formulated with a natural stabilizer. a) Mild Intensity: [0105] [0000] COMPONENT % w/w Pure honey 83.5 Soluble coffee 16.5 b) Strong Intensity: [0106] [0000] COMPONENT % w/w Pure honey 75.2 Soluble coffee 24.8 COMPOSITION 2: Composition for preparing foaming coffee sweetened with honey with at least one natural stabilizer. [0000] COMPONENT % w/w Pure honey 81.50% Soluble coffee 16.50% Natural stabilizer 2.00% [0107] The natural stabilizer used is microcrystalline cellulose (Avicel, Avicel-plus, NovaGel). [0108] The “microcrystalline cellulose” E-461 (i) or MCC (English acronym for Microcrystalline Cellulose) is a partially depolymerised purified cellulose, obtained by treatment with mineral acids of the alpha-cellulose in vegetable fibers. [0000] COMPOSITION 3: Composition for preparing foaming coffee sweetened with spiced honey. [0000] COMPONENT % w/w Pure honey 81.5 Soluble coffee 15.5 Natural stabilizer 2 Spices 1 [0109] The natural stabilizer employed is microcrystalline cellulose (MCC) and the spices are selected from anise, saffron, cardamom, cinnamon, juniper, ginger, nutmeg, vanilla, cloves, and mixtures thereof. In this case, anise and juniper were used in equal parts [0000] COMPOSITION 4: Composition for preparing foaming coffee sweetened with honey with the addition of cinnamon and chocolate. [0000] COMPONENT % w/w Pure honey 81.5 Soluble coffee 14 Natural stabilizer 2 Spices 1 Chocolate (cocoa powder) 1.5 [0110] The natural stabilizer is microcrystalline cellulose (MCC). In addition to the cinnamon used here, other spices can be added in varying proportions depending on the result sought to achieve in the taste of the final product, where such spices are selected from anise, saffron, cardamom, juniper, ginger, nutmeg, vanilla, cloves, and mixtures thereof. [0000] COMPOSITION 5: Composition to prepare foaming coffee with milk sweetened with honey made with powdered milk. [0000] COMPONENT % w/w Pure honey 71.5 Soluble coffee 16.5 Natural stabilizer 2 Powdered milk 10 [0111] The natural stabilizer is microcrystalline cellulose (MCC). [0000] COMPOSITION 6: Composition to prepare foaming coffee with milk sweetened with honey made with condensed milk. [0000] COMPONENT % w/w Pure honey 71.5 Soluble coffee 21.5 Natural stabilizer 2 Condensed milk 5 [0112] The Natural stabilizer is carboxymethylcellulose. [0113] The “carboxymethylcellulose” E-466 or CMC (Carboxymethyl Cellulose English acronym) is a cellulose derivative comprised of carboxymethyl groups bonded to hydroxyl present in some groups of glucopyranose polymers. [0000] COMPOSITION 7: Composition for preparing foaming coffee sweetened with honey with natural essences. [0000] COMPONENT % w/w Pure honey 81.49 Soluble coffee 16.5 Natural stabilizer 2 Natural essences 0.01 [0114] The natural stabilizer is microcrystalline cellulose (MCC). The Natural essences are selected from almond, hazelnut, orange, vanilla, and mixtures thereof. In this case orange essence was used. [0000] COMPOSITION 8: Composition for preparing foaming coffee sweetened with honey with at least one natural stabilizer. [0000] COMPONENT % w/w Pure honey 81.5 Soluble coffee 16.5 Natural stabilizer 2 [0115] The natural stabilizer was locust bean gum. [0116] “Locust bean gum” is also known as carob bean gum or E410, it is a type of galactomannan vegetable gum extracted from the seeds of the carob tree. The fruit of the carob tree is used to prepare the rubber that is used as a stabilizer [0000] COMPOSITION 9: Composition for preparing foaming coffee sweetened with spiced honey. [0000] COMPONENT % w/w Pure honey 83 Soluble coffee 15.5 Natural stabilizer 0.5 Spices 1 [0117] The natural stabilizer is locust bean gum. The spices are selected from anise, saffron, cardamom, cinnamon, juniper, ginger, nutmeg, vanilla, cloves, and their mixtures in varying proportions depending on the flavor you want to achieve. In this case weight equal parts of vanilla, juniper, anise and cardamom was used. [0000] COMPOSITION 10: Composition for preparing foaming coffee sweetened with honey with the addition of cinnamon and chocolate. [0000] COMPONENT % w/w Pure honey 82.5 Soluble coffee 14.5 Natural stabilizer 0.1 Spices 1.3 Chocolate (cocoa powder) 1.6 [0118] The natural stabilizer is locust bean gum. In addition to cinnamon as was used in this example, other spices can be added in varying proportions depending on the result in the flavor that is intended to achieve, where these spices are selected from anise, saffron, cardamom, juniper, ginger, nutmeg, vanilla, cloves, and mixtures thereof. [0000] COMPOSITION 11: Composition to prepare foaming coffee with milk sweetened with honey made with powdered milk. [0000] COMPONENT % w/w Pure honey 72 Soluble coffee 16.5 Natural stabilizer 1.5 Powdered milk 10 [0119] The natural stabilizer es carob gum. [0000] COMPOSITION 12: Composition to prepare foaming coffee with milk sweetened with honey made with condensed milk. [0000] COMPONENT % w/w Pure honey 73 Soluble coffee 21.5 Natural stabilizer 0.5 Condensed milk 5 [0120] The natural stabilizer es carob gum. [0121] “Condensed milk” is basically cow's milk from which the water has been extracted and sugar added has been added, yielding a thick and sweet product. It is preserved for a long time without refrigeration as long as the package remains sealed. Alternatively, it is preferred to employ “evaporated milk” which is a canned milk product that also supports large storage periods due to the dehydration process performed on the raw milk, whereby it eliminates about 60% of the water existing in milk. The latter product is preferred due to the fact that the compositions obtained would be sweetened only with honey. [0000] COMPOSITION 13: Composition for preparing foaming coffee sweetened with honey with natural essences. [0000] COMPONENT % w/w Pure honey 81.49 Soluble coffee 16.5 Natural stabilizer 2 Natural essences 0.01 [0122] The natural stabilizer is carob gum and the natural essences are selected from almond, hazelnut, orange, vanilla, and mixtures thereof. In this case, equal parts of hazelnut and orange were used. [0000] COMPOSITION 14: Composition for preparing foaming coffee sweetened with honey with at least one natural stabilizer. [0000] COMPONENT % w/w Pure honey 81.5 Soluble coffee 16.5 Natural stabilizer 2 [0123] The natural stabilizer is xanthan gum. [0124] “Xanthan gum” or simply “Xanthan” refers to an extracellular polysaccharide produced by the bacterium Xanthomonas campestris . It is a cream colored powder that dissolves in hot or cold water to produce solutions of relatively high viscosity at low concentrations, hence its use as a thickener. [0000] COMPOSITION 15: Composition for preparing foaming coffee sweetened with spiced honey. [0000] COMPONENT % w/w Pure honey 81.5 Natural stabilizer 1 Soluble coffee 16.5 Spices 1 [0125] The natural stabilizer is xanthan gum. The spices are selected from anise, saffron, cardamom, cinnamon, juniper, ginger, nutmeg, vanilla, cloves, and mixtures thereof. In this case equal parts cardamom, vanilla and ginger were used. [0000] COMPOSITION 16: Composition for preparing foaming coffee sweetened with honey with the addition of cinnamon and chocolate. [0000] COMPONENT % w/w Pure honey 81.4 Soluble coffee 16 Natural stabilizer 0.1 Spices 1 Chocolate (cacao powder) 1.5 [0126] The natural stabilizer is xanthan gum. In addition to the cinnamon as used here, other spices can be added in varying proportions depending on the result in the flavor that is intended to achieve, where these spices are selected from anise, saffron, cardamom, juniper, ginger, nutmeg, vanilla, cloves odor, and mixtures thereof. [0000] COMPOSITION 17: Composition for preparing foaming coffee with milk sweetened with honey made with powdered milk [0000] COMPONENT % w/w Pure honey 73.3 Soluble coffee 16.5 Natural stabilizer 0.2 Powdered milk 10 [0127] The natural stabilizer is xanthan gum. [0000] COMPOSITION 18: Composition for preparing foaming coffee with milk sweetened with honey using condensed milk. [0000] COMPONENT % w/w Pure honey 73 Soluble coffee 21.5 Natural stabilizer 0.5 Condensed milk 5 [0128] The natural stabilizer is xanthan gum. [0000] COMPOSITION 19: Composition for preparing foaming coffee sweetened with honey with natural essences. [0000] COMPONENT % w/w Pure honey 81.49 Soluble coffee 17 Natural stabilizer 1.5 Natural essences 0.01 [0129] The natural stabilizer is xanthan gum. The natural essences are selected from almond, hazelnut, orange, vanilla, and mixtures thereof. In this Example natural almond essence was used. [0000] COMPOSITION 20: Composition for preparing foaming milk sweetened with honey. [0000] COMPONENT % w/w Pure honey 82.5 Powdered milk 15.5 Natural stabilizer 2 [0130] The natural stabilizer is microcrystalline cellulose (MCC). [0000] COMPOSITION 21: Composition for preparing foaming milk sweetened with honey with added cinnamon. [0000] COMPONENT % w/w Pure honey 83 Powdered milk 14.5 Natural stabilizer 2 Spices 0.5 [0131] The natural stabilizer is xanthan gum. In addition to the cinnamon as used here, you can add other spices in varying proportions depending on the result in the flavor that is intended to achieve, the spices are selected from anise, saffron, cardamom, juniper, ginger, nutmeg, vanilla, cloves odor, and mixtures thereof. Product Stability [0132] The trial performed were of accelerated stability; which establish a period of shelf We and determine the stability of the foam of the formulated product. [0133] Jars with the compositions were placed for 25 days at different temperatures: oven at 35° C., oven at 25° C., room temperature, refrigerator at 7° C. and refrigerator at 2° C. [0134] After that period of time passed, a visual assessment of each composition and its ability to produce a beverage by adding hot water to the desired characteristics was performed. [0135] Slight variations at 35° C. were seen in the packaging of the compositions prepared without stabilizer. A small separation of form was detected where about 3 to 4 mm of the coffee is darker at the bottom of the product. Products made with various stabilizers were unchanged in appearance for any of the temperatures of the trials. [0136] It is concluded that to obtain a commercially acceptable product for a period of up to two years it is convenient to use stabilizers. [0137] The compositions without stabilizers may have a shelf life of between one year and one and a half years. Foam Stability [0138] Tests were done to make the final beverage to be consumed by the addition of hot drinking water at a temperature between 80 and 98° C. from a height of about 15 cm on each of the compositions coffee, coffee with milk, and milk sweetened with honey prepared according to the present invention process and described above. [0139] We waited for about 35 seconds after mixing, resulting in foam that had a height between about 0.8 cm and about 2.3 cm, which remained until the ready to consume product was cooled to room temperature. [0140] The foam on the beverages obtained with compositions without stabilizer had a foam height development lower than those of beverages obtained from the compositions with a stabilizer. [0000] The products made with various stabilizers presented no change in appearance or in foaming abilities in the trials at the mentioned temperatures. Uses and Applications of the Concentrated Foaming Compositions: Food Industry [0141] The composition for preparing foaming coffee sweetened with honey has the following applications in the food industry, classified by category: [0142] α) Hot drinks: Foaming Coffee. Foaming Coffee with milk (powdered or condensed) Foaming Spiced Coffee—alone or with milk— Foaming Coffee with Chocolate and Cinnamon—Cappuccino— Foaming Coffee flavored with Natural essences/Liqueurs [0148] β) Bonbons: Filling for bonbons [0150] χ) Confectionery: Filling for nougat Filling for sandwich cookies Filling for sweets Filling for cookies [0155] δ) Pastry: Filling for baked goods: cookies, cakes, jelly rolls, etc. [0157] ε) Ice Cream: Flavor base, cover or filling for ice cream or frozen desserts Cosmetic Industry [0159] As a base for the preparation of skin care creams, soap bars, liquid soaps, foams and/or bath salts, lip balms, etc. Pharmaceutical and Biochemical Industry [0160] As a base for granulated or effervescent painkillers, fever reducers, and also for the production of syrups.

A process for preparing a concentrated foaming composition sweetened with honey, including: a) provision and weighing the necessary quantities of raw materials to be used, b) putting pure honey in a mixer and subjecting the honey to beating from about 250 rpm to about 1500 rpm for about 5 to 30 minutes, c) adding at least one raw material selected from soluble coffee, powdered milk and honey to the mixed honey from step b) while it is being mixed, and d) once the desired consistency is achieved, divide the composition obtained in step c) into containers for distribution and marketing. Compositions for making foaming coffee sweetened with honey, foaming coffee with milk sweetened with honey and foaming milk sweetened with honey obtained by this process.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates in general to means for stably supporting an object and more specifically to a self-contained, adjustable support device having a collapsed position for storage and/or transport and having an open position for providing stable supporting surfces for a wide variety of objects. 2. Description of the Prior Art Heretofore, various devices have been used by carpenters and other workmen to support workpieces as the workpiece is cut, filed or otherwise worked on. Typically, such workmen use a pair of sawhorsed or tesles to support a workpiece or the like. However, typical sawhorses and tresles are often disadvantageous because they are typically not adjustable or collapsable and often do not have adequate strength. Other disadvantages include bulkiness, storage and transport difficulty and a tendency to become weakened through repeated use. Further, additional support means such as transverse rails and the like must be used in conjunction with such typical sawhorses and tresles when supporting small, large, odd shaped, or flimsey objects. A preliminary patentablility search in class 248, subclass 439 and class 182, subclasses 153, 154, and 155 produced the following patents: Fassler, U.S. Pat. No. 965,173; Varache, U.S. Pat. No. 1,150,794; Beland, U.S. Pat. No. 1,298,867; Tyler et al, U.S. Pat. No. 1,860,875; Strand, U.S. Pat. No. 1,876,787; Bowers, U.S. Pat. No. 2,897,911; Barthel, U.S. Pat. No. 3,817,349 and Hendrickson et al, U.S. Pat. No. 3,945,328. None of the above patents or prior art devices disclose or suggest the present invention. SUMMARY OF THE INVENTION The present invention provides a support device of general utility value, particularly useful to work men for supporting workpieces such as lumber or other objects for sawing, drilling, painting, repair and the like. The support device of the present invention comprises, in general, a support beam; leg structure; and bracket means pivotally attaching the support beam to the leg structure, the bracket means including pivot rod means extending through the beam member for allowing pivotal movement relative thereto, support means rigidly mounted relative to the pivot rod means for supportingly engaging the beam member, and attachment means rigidly mounted relative to the pivot rod means and the support means for attaching the pivot rod means and support means to the leg structure. An object of the present invention is to provide a new and improved support device which is substantially compact, easily adjustable, collapsable, storable, transportable, and adequately strong, that does not become weak or wobbly through use, and that is substantially self-stabilizing on uneven floor or ground conditions. Another object of the present invention is to provide a latch bracket which will lock a pair of legs to a central beam either in a legs extended position or a legs collapsed position, and which will allow each pair of legs to be adjusted to various positions along the beam. An additional object of the present invention is to provide a support device which can be used as an individual means for support small, large, odd shaped, or flimsey objects by means of providing multiple support surfaces lying in substantially the same plane, thus eliminating the need for multiple support devices and/or supplemental support means for such objects and for supporting such objects in a way that a workman is not limited or hindered in access to the supported objects by the support device itself. Another object of the present invention is to provide means for out-of-the-way storage of tools and the like. Still another object of the present invention is to provide a construction of the support device which is simple, practical and economical to manufacture and to use. Many other objects, advantages and/or features of the present invention will be at once apparent or will become so as the preferred embodiment of the present invention is hereinafter described. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the support device of the present invention. FIG. 2 is a perspective view of a bracket means of the support device of the present invention. FIG. 3 is a perspective view of a leg means of the support device of the present invention with certain portions of the support beam structure shown in broken lines. FIG. 4 is a perspective view of a thumbscrew of the support device of the present invention. FIG. 5 is a perspective view of strut of the support device of the present invention with certain portions of the support beam structure and leg means shown in broken lines. FIG. 6 is a side elevational view of the support device of the present inention with portions thereof broken away for clarity. FIG. 7 is similar to FIG. 6 but with the leg means thereof in folded, collapsed positions. FIG. 8 is a top plan view of FIG. 7. FIG. 9 is a somewhat diagrammatic sectional view of a portion of the support device of the present invention showing certain features of the first bracket means, the first leg means and support beam. FIG. 10 is similar to FIG. 9 but shows the leg means in a folded, collapsed position. FIG. 11 is a sectional view substantially as taken on line XI--XI of FIG. 9. FIG. 12 is a sectional view similar to FIG. 11 but showing the bracket means in a moved position. DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred embodiment of the support device 11 of the present invention as clearly shown in FIG. 1 includes a support structure or means 12 that includes an elongated longitudinal support beam member 13 having an upper surface 13' and a lower surface 13" (see FIGS. 11 and 12) and having a first end 15 and a second end 17; a first leg structure or means 19 for supporting the first end 15 of the support beam member 13; and a second leg structure or means 21 for supporting the second end 17 of the support beam member 13 (see, in general, FIG. 1). A first bracket means 23 is provided to attach the first leg means 19 relative to the first end of the support beam member 13 and a second bracket means 25 is provided to attach the second leg means 21 relative to the second end 17 of the support beam member 13. The first and second bracket means 23, 25 are constructed so as to allow the first and second leg means 19, 21 to move between an extended, in use or open position with the leg means 19, 21 positioned substantially perpendicular to the support beam member 13 (see FIGS. 1, 6 and 9), and a collapsed, closed or stored position in which the leg means 19, 21 are positioned substantially parallel with the support beam member 13 (see FIGS. 7, 8 and 10). The first leg means 19 preferably includes an inverted substantially U-shaped body member 27 having a first leg 29 with a first end 31 and a second end 33, a second leg 35 with a first end 37 and a second end 39, and a web or bight portion 41 extending between the second end 33, 39 of the first and second legs 29, 35 (see, in general, FIG. 3). The body member 27 is preferably constructed of an elongated length of metal tubing which may be bent or otherwise formed to the inverted U-shape as will now be apparent to those skilled in the art. Thus, for example, the body member 27 may be constructed out of 18 gauge 3/4 inch by 11/2 inch rectangular metal tubing. A generally horizontal cross member 43 preferably extends between the first and second legs 29, 35 at a point between the first and second end thereof substantially parallel to the bight portion 41. The cross member 43 is preferably constructed of metal tubing and may be welded or otherwise fixedly attached to those skilled in the art. Thus, for example, the cross member 43 may also be constructed of 18 gauge 3/4 inch by 11/2 inch rectangular metal tubing. A strut 45 preferably extends bewteen the cross member 43 and the bight portion 41. The strut 45 (see FIG. 5) is preferably channel-shaped having a first side portion 47 having an aperture 48 therethrough, a second side portion 49 having an aperture 50 therethrough, and a back portion 51 extending between the first and second side portions 47, 49. An aperture 52 is provided through the back portion 51 for reasons which will hereinafter become apparent. The aperture 52 is preferably adapted to screwably receive a threaded shaft as will hereinafter become apparent. Thus, the aperture 52 may be threaded as will be apparent to those skilled in the art or a threaded nut 52' (see FIGS. 9 and 10) may be fixedly attached to the back portion 51 concentrically of the aperture 52, etc. The strut 45 preferably has a notch 53 therein for receiving the bight portion 41 of the body member 27 as clearly shown in FIG. 3, thus allowing the upper ends or ears 47', 49', of the first and second side portions 47, 49 to extend above the bight portion 41 for reasons which will hereinafter become apparent. The strut 45 is preferably constructed of 14 gauge sheet metal or the like and may be easily cut and bent into the desired shape. The strut 45 may be fixedly attached to the cross member 43 and bight portion 41 in any manner now apparent to those skilled in the art such as by being welded thereto. Shoes 55 constructed of plastic or the like may be secured ot the first ends 31, 37 of the first and second legs 29, 35. The second leg means 21 is preferably substantially identical in construction and function to the first leg means 19 and the above detailed description of the first leg means 19 should be referred to for a complete understanding of the second leg means 21. Similar parts and elements of the first and second leg means 19, 21 bear the same reference numerals in the drawings. The first bracket means 23 (see, in general, FIG. 2) includes a pivot rod means 57 extending through the beam member 13 (see FIGS. 11 and 12) for allowing pivotal movement relative thereto. The first bracket means 23 also includes support means 59 rigidly mounted relative to the pivot rod means 57 for supportingly engaging the beam member 13, and attachment means 61 rigidly mounted relative to the pivot rod means 57 and the support means 59 for removably attaching the pivot rod means 57 and support means 59 to the first leg means 19. Preferably, the first bracket means 23 is constructed primarily of heavy gauge metal having a body portion 63 bent at one end to form a flange 65 having a slot 67 and outwardly angled distal ends 68 for defining the attachment means 61 in a manner which will hereinafter become apparent, and bent at the other end to form a first flange 69 and a second flange 71 which coact to define the support means 59 in a manner which will hereinafter become apparent. As clearly shown in FIGS. 2, 9 and 10, the outer faces of the first and second flanges 69, 71 are located perpendicular to one another for reasons which will hereinafter become apparent. The body portion 62 may have one or more strengthening or reinforcing flanges 72 (see FIGS. 11 and 12) extending the length thereof to increase the strength and stability of the bracket means 23 as will now be apparent to those skilled in the art. The pivot rod means 57 may consist simply of an elongated rod 73 such as a typical bolt or the like having a first end 75 fixedly secured to the body 63 by welding or the like and having a second end 77. The second end 77 of the rod 73 preferably has a transverse aperture 79 therethrough for removably receiving a hitch pin clip 81 or the like for reasons which will hereinafter become apparent. The second bracket means 25 is preferably identical in construction and function to the first bracket means 23 and the above detailed description of the first bracket means 23 should be referred to for a complete understanding of the second bracket means 25. Similar parts and elements of the first and second bracket means 23, 25 bear the same reference numerals in the drawings. The support beam member 13 preferably consists of an elongated length of lumber such as a typical "two by four" or the like. Transverse apertures 83 are provided through the support beam member 13 for allowing the rod 73 of the pivot rod means 57 of each bracket means 23, 25 to pass therethrough. Preferably, a plurality of spaced apart apertures 83 are provided along the length of the support beam member 13 to allow adjustment of the leg members 19, 21 toward and away from one another as will be apparent to those skilled in the art. The support means 12 preferably includes structure for defining a pari of elongated, transverse support beam members located one substantially adjacent each end 15, 17 of the longitudinal support beam member 13 and positioned substantially transverse thereto. The transverse support beam members may be defined merely by the upper surfaces of the bight portions 41 of the first and second leg means 19, 21. Preferably, however, the transverse support beam members include a plurality of slats 85 for being fixedly attached to the upper surfaces of the bight portions 41 of the first and second leg means 19,2 1 as clearly shown in FIG. 1. Each slat 85 preferably consists of an elongated lumber such as a typical "two by four" or the like and is preferably fixedly attached to the respective bight portion 41 by lag screws 87 or the like with the upwardly extending ears 47', 49' of the side portions 47, 49 acting as end stops for the slats 85 (see FIG. 3). Thus, the upper surface 13' of the longitudinal support beam member 13 and the upper surfaces of the slats 85 are planar relative to one another whereby an object can be stably supported on the support means 12 even if it extends across the beam member 13 and one or more slats 85. The support means 12 is thereby defined by an elongated longitudinal surface having first and second ends, a first transverse surface extending across the longitudinal surface adjacent the first end thereof, and a second transverse surface extending across the longitudinal surface adjacent the second end thereof, with the longitudinal and transverse surfaces planar to one another and with the transverse surfaces located intermediate the first and second ends of the longitudinal surface. The attachment means 61 preferably includes a thumbscrew 89 (see, in general, FIG. 4) having a threaded body 91 for extending through the slot 67 in the flange 65 of the body 63 and into the threaded aperture 52 in the strut 45 to couple the respective bracket means 23, 25 to the respective strut 45. The thumbscrew 89 preferably has a head 93 for allowing it to be easily turned and a flange 95 for acting as a stop against the flange 65. To connect the first leg means 19 to the support beam member 13 with the first bracket means 23, the support beam member 13 is positioned on the strut 45 between the upwardly extending ears 47', 49' of the first and second side portions 47, 49 thereof and with surface 13" adjacent to the upper surface of bight portion 41 of the bodymember 27, with one of the apertures 83 through the support beam member 13 aligned with the apertures 48, 50 through the first and second side portions 47, 51 of the strut (see, in general, FIG. 11). Then the rod 73 of the pivot rod means 57 is inserted through the aligned apertures 48, 50, 83. Once the rod 73 is inserted through the apertures 48, 50, 83, the hitch pin clip is inserted through the aperture 79 of the rod 73 to prevent inadvertent removal of the rod 73 from the apertures 48, 50, 83. the body 63 of the bracket means 23 can then be positioned so that the flange 65 is positioned adjacent to the threaded aperture 52 in the back portion 51 of the strut 45 with the slots 67 extending about the body 91 of the thumb screw 89 and with the flange 71 engaging the bottom of the beam member 13 (see FIG. 9). The thumb screw 89 can then be tightened to cause the support means and pivot means of the bracket means 23 to coact to wedge the support beam member 13 therebetween. More specifically, as the thumb screw 89 is tightened, the flange 95 thereof will cause the bracket means 23 to pivot somewhat about the pivot rod means 57 to cause the flange 71 to exert force against the lower surface 13" of the support beam member 13 (see FIG. 9) causing the lower surface 13" of the support beam member 13 to push against the bight portion 41 of the body member 27 while the lower radial surface of the rod 73 will exert force against the lower radial surface of the aperture 83. The outwardly angled distal ends 68 of the flange 65 will then coact with the wedge like force being applied to ensure that the bracket means 23 remains in position. When the support device 11 is thus set up in the operative position with both leg means 19, 21 properly locked in place by way of the first and second brackets means 23, 25 respectively, the support device 11 will be structurely stable. Even if the support device 11 is set up on an uneven floor or ground surface, the construction allows the support device 11 to flex slightly and remain substantially stable. To collapse the support device 11, the thumb screw 89 is loosened several turns. This will relieve the locking forces at the joint and allow the body 63 to be laterally moved to a position that by the time the hitch pin clip 81 comes in contact with the side portion 49 of strut 45, the flanges 65, 69, 71 are disengaged from the strut 45 and the beam member 13 respectively to allow the body member 27 to be rotated to a collapsed position (see FIG. 12). To lock the body member 27 in the collapsed position, the body 63 is again moved laterally to position the flange 65 over the threaded aperture 52 and the thumb screw 89 is then tightened with the flange 69 engaging the upper surface 13' of the beam member 13 (see FIG. 12) to thereby lock the body member 27 in the collapsed position. A board 97 or a similar member may be positioned across the crossmembers 43 of the leg means 19, 21 when in the extended position as clearly shown in FIG. 6 to provide a shelf or the like for out-of-the-way storage of tools and the like. It should be noted that the first and second legs 29, 35 of the second leg means 21 may be spaced slightly farther apart from one another than the first and second legs 39, 25 of the first leg means 19 to allow portions of the first leg means 19 to nest within portions of the second leg means 21 when the support device 11 is in the collapsed position as clearly shown in FIG. 8. From the above, it will be seen that all the recited objects, advantages, and features of the present invention have been demostrated as achievable in a highly practical and economical to manufacture and use embodiment of the present invention. Although the present invention has been described and illustrated with respect to a preferred embodiment thereof and a preferred use therefore, it is not to be so limited since changes and modifications can be made therein which are within the full intended scope of the invention.

A self-contained adjustable support device designed to provide stable work supporting surfaces for a wide variety of objects in the legs extended position and also provides a legs collapsed position for storage and/or transport. The support device includes a pair of latch brackets with each latch bracket constructed to lock a pair of legs to a central beam either in the legs extended position or the legs collapsed position; and to allow each pair of legs to be adjusted to various positions along the beam.

BACKGROUND [0001] 1. Field of the Invention [0002] The present invention relates to detecting redirection or interception of data and in particular to a method of detecting a redirecting process in the course of a bi-directional non-contact making transmission of data. [0003] 2. Description of the Related Technology [0004] Systems for the bi-directional non-contact making transmission of data are preferably used in identification systems. In general, these systems consist of a base station and a transponder. These systems are utilised for authentication purposes in the field of motor cars, a main field of usage. In order to achieve a high level of security for the authentication process, the distance over which the communication can take place is restricted to just a few meters in the case of a so-called “passive entry” system, i.e. the opening of a vehicle by pulling the door handle. In an identification system, it is important that the time required for the authentication process be kept short. The total time for the authentication process in the field of motor vehicles is generally between 50 and 130 msec. In order to prevent unauthorised authentication by means of a redirecting process for example, methods have been developed for detecting the manipulation and for terminating the authentication process should this be necessary. [0005] A first method of detecting redirection or interception during an authentication process is known from German patent document DE 10005503, wherein at least one characteristic parameter of the transmitted electromagnetic wave is altered in reversible manner. To this end, a reply signal, which, for example, has been altered in frequency relative to the interrogation signal in a second transmitting and receiving unit (a transponder), is transmitted back to the first transmitting and receiving unit. In the first transmitting and receiving unit (the base station), the frequency of the reply signal is changed back again and compared with the frequency of the originally transmitted interrogation signal. If the value detected thereby lies within a pre-defined interval, one can virtually exclude the possibility that redirection has occurred. [0006] Another method of detecting redirection in the course of an authentication process is known from German patent document DE 198 27 722. In order to prevent unauthorised opening of a motor vehicle, the power of the transmitted interrogation signal and that of the reply signal are bit-modulated. The mask used for the modulation process is produced by means of a secret key which is known to both the base station and the transponder. A maximum permissible time period is laid down, this being based on the assumption that the modulation of the transmitted power would have to be evaluated in the event of a redirecting process and that an additional time delay would thereby ensue between the transmission of the interrogation signal and the reception of the reply signal. If the time difference between the interrogation and the reply signals is greater than the redefined minimum time, then it is assumed that redirection has occurred and the authentication process is terminated. [0007] The disadvantage of the previous methods is that redirection is not impeded or is not made difficult enough when using the previous methods. It is true that the reversible alteration of the frequency makes the frequency conversion process that is generally carried out during a redirecting process more difficult, but the degree of difficulty involved is determined only by the precision of the frequency conversion process within the redirecting device. Insofar as it is possible to effect a high precision conversion and re-conversion of the frequency in the redirecting devices, then an authentication process can be carried out and unauthorised access to a motor vehicle for example can be obtained. In the case of the other known method, which attempts to detect redirection by encoding the modulation of the transmitter power, this can already be done by the currently known devices (transceivers) that are used for redirecting purposes. Thus the known transceivers compensate for the additional attenuation losses, which are caused by the greater length of the signal path during the redirecting process, by subjecting the signals to linear amplification without thereby altering the relative modulation of the transmitter power. However, as the modulation of the transmitter power does not have to be decoded, the time loss postulated by the method does not occur and redirection cannot be detected. Neither of the two methods offers sufficient protection from unauthorised access within an authentication process. SUMMARY OF THE INVENTION [0008] Aspects of the present invention seek to provide a method which detects a redirection of the signals. [0009] According to the present invention, there is provided a method of detecting a redirecting process in the course of a bi-directional non-contact making transmission of data between a first transmitting and receiving unit and a second transmitting and receiving unit wherein the first transmitting and receiving unit transmits an interrogation signal, the value of the amplitude (A 1 ) of the received interrogation signal is measured by the second transmitting and receiving unit, the measured value of the amplitude (A 1 ) is transmitted back in a reply signal, and the value of the amplitude (A 2 ) of the received reply signal is measured by the first transmitting and receiving unit and compared with the returned value of the amplitude (A 1 ). [0010] In embodiments of the present invention, in the course of a bi-directional non-contact making transmission of data, it is determined as to whether a redirecting process is taking place by means of a comparison of the attenuation characteristics of the transmission paths between a first transmitting and receiving unit and a second transmitting and receiving unit. To this end, the interrogation signal transmitted by the first transmitting and receiving unit is measured in regard to the amplitude thereof in the second transmitting and receiving unit. The measured amplitude value is transmitted back to the first transmitting and receiving unit in a reply signal, preferably, in encoded form. Furthermore, the amplitude of the received reply signal is determined in the first transmitting and receiving unit and is compared with the returned value of the amplitude, whereafter a value is assigned to a redirection indicator in dependence upon the comparison. One can exclude the possibility that a redirecting process is occurring, if the result of the comparison of the amplitude values falls within a predefined interval. [0011] Methods in accordance with the present invention are based upon the principle that in the case of a communication process not subjected to redirection, the transmission path will be symmetrical in regard to the attenuating behaviour thereof, i.e. both the forward path and the return path will have the same attenuation characteristics since the two transmitting and receiving units utilise a single respective antenna for the transmission and reception of signals. If the signals are prolonged by means of a redirecting device, then the redirecting device is utilising different antennae for transmitting and receiving purposes and is amplifying the signals in order to compensate for the additional attenuation caused by the redirecting device. Differing coupling factors between the antennae in the transmitting and receiving units and those in the redirecting device are associated with the different antennae used for transmitting and receiving purposes in the redirecting device, these differing coupling factors removing the symmetry of the transmission paths and heavily attenuating, in different manners, the amplitude of the interrogation signal in comparison with the amplitude of the reply signal. [0012] In a further development of the method, the information regarding the attenuating characteristics of the signal path, which can be extrapolated from the measured value of the amplitude, is protected from unauthorised access. To this end, the digitalised value of the amplitude is inserted into the reply signal in encoded form. For an authentication process in which the authorisation is checked by examining encoded ID codes, the value of the amplitude could be coded using the same key as that with which the ID code of the respective transmitting and receiving unit was encoded prior to the transmission. By virtue of such an encoding process, it becomes impossible to evaluate the attenuation information using justifiable resources. [0013] In another embodiment of the method, the comparison of the amplitudes is carried out within a predefined time window, whereby a check can be made as to whether the reply signal immediately follows the interrogation signal in time. Consequently, any change in position of either of the two transmitting and receiving units during the communication process between the first transmitting and receiving unit and the second transmitting and receiving unit will be prevented from removing the symmetry of the transmission path but a suspected redirecting process will be indicated by means of the resultant differing attenuations of the amplitudes. Furthermore, a redirecting device will be prevented from compensating for the asymmetry of the attenuation characteristics by trying to repeatedly change its signal amplification factor. [0014] In another embodiment of the method, redirection is detected by comparing the frequency of the interrogation signal with the frequency of the reply signal, this being done in addition to the comparison of the amplitudes made by the first transmitting and receiving unit. In order to make the interval used for the frequency comparison as small as possible, it is advantageous if the second transmitting and receiving unit carries out a frequency coupling process with the frequency of the interrogation signal transmitted by the first transmitting and receiving unit. The carrier frequency can thereby be regenerated for the purposes of modulating the data in the reply signal. Since the frequency of the reply signal and that of the carrier signal are identical, the smallest deviations of the carrier frequency can be detected. A process of redirecting at the same frequency is thereby made extremely difficult since the functioning of the redirecting device will be adversely affected due to feedback. A frequency conversion process effected by the redirecting device within the redirection path leads to the carrier frequency being subjected to a frequency off-set. Should the result of the frequency comparison lie within the predefined interval, then it is possible to exclude the likelihood of a redirecting process. [0015] In another embodiment of the method, the first transmitting and receiving unit also checks, in addition to the comparison made in respect of the amplitudes and the frequencies, as to whether the carrier signal remains uninterrupted, apart from field-gaps during the transmission of the interrogation signal, until the reception of the reply signal. Consequently, it is extremely difficult for a redirecting device to convert the carrier frequency for the purposes of redirecting the transmission without this being detected by the first transmitting and receiving unit. Amplification of the signals, which would compensate for the additional attenuation caused by the lengthening of the signal path, has to be effected at the frequency of the carrier by the redirecting device. In so doing however, the redirecting device can only compensate for the additional attenuation losses insofar as the signal amplification factor thereof remains smaller than the value of the decoupling between its transmitting and receiving antennae. On the other hand, if the circuit amplification factor within the redirecting device is greater than one, then this would result in feedback so that the functioning of the redirecting device would be extremely badly affected. [0016] Experiments made by the applicant have shown that it is advantageous if a comparison of the amplitude values and a comparison of the frequencies is effected within an authentication process whilst checking the authorisation by means of an ID code. Thus, these methods do not require any additional time for detecting a redirecting process and can be employed, to advantage, for applications in the field of motor vehicles. Moreover, in applications in the motor vehicle field, the time span of 50-130 msec allowed for the authentication process is too short, except at intolerable expense, for decoding the amplitude values which are transmitted back with the reply signal, or, for compensating for the differing attenuation characteristics on the forward and return paths by means of some other method. Consequently, the possibility of unauthorised authentication by means of a redirecting process can be reliably excluded. BRIEF DESCRIPTION OF THE FIGURES [0017] Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, of which: [0018] [0018]FIG. 1 shows an embodiment of the invention in the form of a method for determining the attenuation of the amplitudes in a bi-directional data transmission system involving a redirecting process; [0019] [0019]FIG. 2 shows an embodiment of the invention in the form of a method for determining the attenuation of the amplitudes whilst simultaneously comparing the carrier frequencies when there is no redirection; and [0020] [0020]FIG. 3 shows a flow diagram for the authentication process in conjunction with the embodiment illustrated in FIG. 2. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0021] The purpose of the embodiment depicted in FIG. 1 is to detect redirection or interception of data during an exchange of data between a first transmitting and receiving unit and a second transmitting and receiving unit by making a comparison between the attenuation of the amplitudes on the forward path and the return path. An arrangement of this type can be employed for authentication purposes in systems in the motor vehicle field for example, so as to detect a redirecting process. The system illustrated consists of a first sending and receiving unit RXTX 2 which will be referred to hereinafter as the base station, a second transmitting and receiving unit RXTX 1 which will be referred to hereinafter as the transponder. Moreover, there is also depicted a redirecting device WL which lengthens the communication paths between the base station RXTX 2 and the transponder RXTX 1 . The communication path from the base station to the transponder will be referred to as the UPLINK, whereas the reverse communication path will be referred to as the DOWNLINK. The construction of the individual devices will now be explained. [0022] The base station RXTX 2 consists of an oscillator unit OSC 2 which produces a carrier frequency F 2 that is used for modulation purposes in an output amplifier TX 2 . Using the data delivered by a data processing unit DP 2 , the output amplifier TX 2 produces a modulated output signal F 2 OUT which is transmitted in the form of an interrogation signal having the power P 2 OUT by means of a transmitting and receiving antenna AN 2 . Furthermore, the transmitting and receiving antenna AN 2 is connected to an input amplifier RX 2 so as to amplify an incoming input signal F 2 IN having an input power P 2 IN and pass it on to a signal processor SP 2 . The signal processor SP 2 measures the magnitude of the amplitude of the input signal F 2 IN and passes the measured value A 2 to the data processing unit DP 2 . Furthermore, the signal processor SP 2 demodulates the input signal F 2 IN and passes on the data recovered from the carrier signal to the data processing unit DP 2 . [0023] As regards the lengthening of the UPLINK communication path by the redirecting device WL, the interrogation signal transmitted by the base station RXTX 2 is passed on from a first receiving antenna E 1 to an amplifier RY 1 which then retransmits this interrogation signal that has been amplified by the factor G 1 by means of a first transmitting antenna S 1 . As regards the lengthening of the DOWNLINK communication path by the redirecting device WL, a reply signal transmitted by the transponder RXTX 1 is passed on from a second receiving antenna E 2 to a second amplifier RY 2 which then retransmits the reply signal that has been amplified by the factor G 2 from a second transmitting antenna S 2 . [0024] The transponder RXTX 1 consists of an oscillator unit OSC 1 which produces a carrier frequency F 1 that is used for modulation purposes in an output amplifier TX 1 . Using the data delivered by a data processing unit DP 1 , the output amplifier TX 1 produces a modulated output signal F 1 OUT which is transmitted in the form of a reply signal having the transmission power P 1 OUT by means of a transmitting and receiving antenna AN 1 . Furthermore, the transmitting and receiving antenna AN 1 is connected to an input amplifier RX 1 so as to amplify an incoming input signal F 1 IN having a reception power P 1 IN and pass it on to a signal processor SP 1 . The signal processor SP 1 measures the magnitude of the amplitude of the input signal F 1 IN and passes on the measured value A 1 to the data processing unit DP 1 . Furthermore, the signal processor SP 1 demodulates the input signal F 1 IN and passes on the data derived from the carrier signal to the data processing unit DP 1 . [0025] For the UPLINK, the magnitude of the attenuation between the base station RXTX 2 and the redirecting device WL is defined by a coupling factor K 21 , and the attenuation between the redirecting device and the transponder is defined by a coupling factor K 11 . In a corresponding manner for the DOWNLINK, the attenuation between the transponder RXTX 1 and the redirecting device WL is defined by a coupling factor K 12 , and the attenuation between the redirecting device WL and the base station RXTX 2 is defined by a coupling factor K 22 . Furthermore, the coupling between the antennae E 1 and S 2 is defined by a factor KRY 21 , and the coupling between the antennae S 1 and E 2 is defined by a factor KRY 12 . [0026] The manner in which the arrangement functions will now be explained. In the UPLINK, the communication path is lengthened by the redirecting device WL, in that the redirecting device WL receives an interrogation signal transmitted by the base station RXTX 2 and, after amplification, retransmits it. The interrogation signal is demodulated by the transponder RXTX 1 and the measured value of the amplitude A 1 of the interrogation signal is retransmitted in the form of data in a reply signal for the DOWNLINK. Then, in the DOWNLINK, the communication path is lengthened by the redirecting device WL, in that the received reply signal is amplified and transmitted to the base station RXTX 2 . The base station RXTX 2 demodulates the received reply signal and compares the value of the amplitude A 1 that has been retransmitted with the reply signal with the measured value of the amplitude A 2 of the reply signal in the data processing unit DP 2 . If the two values of the measured amplitudes differ, then a digit 1 is stored in an internal memory by the data processing unit DP 2 , and an indication is given that redirection has occurred. If the result of the comparison falls within a predefined interval, then the digit zero is stored in the memory to show that it can be concluded that a redirecting process has not occurred. [0027] In the case of a predefined transmitting power P 2 OUT and P 1 OUT and a predefined amplification of the input signals P 2 IN and P 1 IN by the base station RXTX 2 and the transponder RXTX 1 , the values A 1 and A 2 of the amplitudes of the interrogation signal and the reply signal are dependent on the coupling factors for the UPLINK and the DOWNLINK and upon the amplification factors G 1 and G 2 in the redirecting device WL. In the present example, the following relationship applies for a coupling factor KUL in the case of redirection in the UPLINK: KUL=K 21 +G 1 +K 11 [0028] and a coupling factor KDL for the DOWNLINK is given by: KDL=K 12 +G 2 +K 22 [0029] As a result of the asymmetry between the transmission paths in the UPLINK and the DOWNLINK, the two coupling factors KDL and KUL and the attenuation of the amplitudes A 1 and A 2 are different. In contrast thereto, the transmission path will exhibit a symmetrical attenuation characteristic if the redirecting device should be removed from the communication path. In this case, the following relationship exists for the two coupling factors KDL and KUL in the UPLINK and the DOWNLINK: KDL=KUL [0030] Furthermore, due to the additional coupling factors and the free space attenuation included therein, the attenuation of the amplitudes will be greater in the event of redirection than would be the case without redirection. Based on the difference in the attenuation characteristics when the redirecting device WL is present compared with the case when the redirecting device WL is absent, a reliable method of detecting redirection is obtained by the process of comparing the amplitudes A 1 and A 2 . This also applies in the case where the redirecting device WL attempts to compensate for the asymmetry of the attenuation characteristic by means of the amplification processes G 1 and G 2 since, without undue expenditure, this cannot be carried out without knowledge of the distances involved in the communication or knowledge of the coupling factors K 11 to K 22 . Insofar as the redirecting device WL effects amplification of the amplitudes A 1 and A 2 on the carrier frequency F 1 , the coupling factors KRY 12 and KRY 21 determine the maximum permissible degree of amplification G 1 and G 2 . In order to prevent oscillations occurring in the redirecting device WL due to feedback, the circuit amplification factor of the redirecting device must remain below 1. [0031] In a further embodiment which is illustrated in FIG. 2, a comparison of the carrier frequencies of the interrogation signal and the reply signal is carried out in addition to the comparison of the amplitudes that has already been described with reference to FIG. 1 in the case of communication between the base station RXTX 2 and the transponder RXTX 1 . Accordingly, the functional construction of the base station RXTX 2 and the transponder RXTX 1 described hereinafter is identical, except for the aforesaid extension, with the functions illustrated in FIG. 1. Furthermore, in the embodiment illustrated, the communication between the base station RXTX 2 and the transponder RXTX 1 is effected without a redirecting process being involved, so that the coupling factor KUL for the UPLINK is identical to the coupling factor KDL for the DOWNLINK. A preferred utilisation of the embodiment within an authentication process will be explained in conjunction with the explanations given in connection with FIG. 3. [0032] Within the base station RXTX 2 , the carrier signal F 2 produced by the oscillator OSC 2 is additionally supplied to a frequency comparison unit FC, the output of which is connected to the data processing unit DP 2 . Furthermore, the reply signal, which has been amplified by the receiving amplifier RX 2 and whose carrier has been regenerated by means of a unit CLK 2 , is supplied to the frequency comparison unit FC. The oscillator unit OSC 1 is replaced by a unit CLK 1 in the transponder RXTX 1 . The reply signal amplified by the input amplifier RX 1 is supplied to the unit CLK 1 for the purposes of regenerating the carrier. Following the regeneration process, the carrier is supplied at a frequency F 21 to the output amplifier TX 1 for a fresh modulation process whereafter it is transmitted. [0033] The manner in which the arrangement functions will now be explained. At the beginning of the transmission of the interrogation signal, the unmodulated carrier signal F 2 is supplied to the frequency comparison unit FC. As soon as the transponder RXTX 1 receives the interrogation signal, an unmodulated carrier having the frequency F 21 is obtained by regenerating the carrier signal with the aid of the unit CLK 1 , and this is then supplied to the transmitting amplifier TX 1 for a fresh modulation process and retransmission to the base station RXTX 2 in the form of a reply signal. A rigid frequency coupling process is thereby carried out. As soon as the reply signal has been received in the base station RXTX 2 , the carrier having the frequency F 21 , which is derived from the reply signal by the unit CLK 2 , is supplied to the frequency comparison unit FC for the purposes of comparing the frequencies of the interrogation signal and the reply signal. Consequently the frequency F 2 of the oscillator unit OSC 2 and the frequency F 21 obtained from the reply signal are applied to the unit FC. The frequency comparison unit FC will supply a signal to the data processing unit DP 2 insofar as the two frequencies are equal. If the evaluation of the amplitudes that was carried out simultaneously by the data processing unit DP 2 also results in the two values of the amplitudes A 1 and A 2 being equal then one can exclude the possibility of a redirecting process. [0034] The flow diagram for an authentication process based on the embodiment illustrated in FIG. 2 will be described in connection with FIG. 3. [0035] Following the start of the authentication process, by actuating the door handle of a vehicle for example, the output amplifier TX 2 in the base station RXTX 2 transmits an interrogation signal SN 2 , which preferably incorporates encoded data, during a first process step TRANSMIT SN 2 . In a succeeding process step RECEIVE SN 2 , the interrogation signal is amplified by the input amplifier RX 1 in the transponder RXTX 1 and it is then passed on. Whilst the unit CLK 1 derives the carrier from the interrogation signal in a process step EXTRACT F 2 , the value of the amplitude A 1 is measured and the data is separated from the carrier within the signal processing unit SP 1 in the course of the process steps MEASURE AM 1 and EXTRACT DATA which run in parallel. In a following process step DECRYPT DATA, the data is decoded and is then checked for agreement with an internally stored code in a query step ID-CODE. If the ID code is not valid, the authentication process comes to an end and a reply signal will not be sent back. If the ID code is valid then the measured value of the amplitude A 1 is encoded in a following process step ENCRYPT, whereafter it is retransmitted in the form of a reply signal by the output amplifier TX 1 in the course of a succeeding process step TRANSMIT SN 1 . Following the reception of the reply signal in the base-station RXTX 2 , which is characterised by the process step RECEIVE SN 1 , the value of the amplitude A 2 is measured and the data is separated from the carrier within the signal processing unit SP 2 during the process steps MEASURE AM 2 and EXTRACT DATA which run in parallel simultaneously with a process step EXTRACT F 21 in which the unit CLK 2 regenerates the carrier for the frequency comparison process. In a succeeding process step DECRYPT DATA, the data is decoded and a check is made during a query step ID-CODE as to whether the retransmitted ID code matches an internally stored code. If the ID code is not valid, the authentication process comes to an end. If the ID code is valid, it is checked in the two succeeding query steps F? and A? as to whether the frequency F 2 matches the frequency F 21 and as to whether the ratio of the amplitudes A 1 and A 2 matches a predetermined value. If the result of one of these queries is negative then the authentication process comes to an end. If the result of both queries is positive, then the authentication process has been successfully completed i.e. the doors of the vehicle are unlocked in a succeeding process step UNLOCK. [0036] It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations.

In a method of detecting redirection or interception during a bi-directional non-contact making data transmission, the attenuation (A 1 ) of the amplitude over the forward path is compared with the attenuation (A 2 ) of the amplitude over the return path. The attenuation (A 1 ) over the forward path is transmitted in encoded form with the reply signal. If the attenuation values determined thereby are of the same magnitude, then the likelihood of a redirecting process can be excluded. In order to additionally increase the security of the system, the carrier frequency (F 2 ) of the interrogation signal can also be compared with the carrier frequency (F 21 ) of the reply signal. The signals can also incorporate an ID code.

CROSS REFERENCES TO RELATED APPLICATIONS [0001] The present application claims priority to Japanese Patent Applications JP 2006-330352 and JP 2007-160964 filed in the Japan Patent Office on Dec. 7, 2006 and Jun. 19, 2007, respectively, the entire contents of which is being incorporated herein by reference. BACKGROUND [0002] The present application relates to a bilirubin oxidase mutant having thermal stability. More specifically, the present application relates to a bilirubin oxidase mutant having prescribed levels or more of heat resistance in addition to enzymatic activity. [0003] An “enzyme” is a biocatalyst for allowing many reactions relative to the maintenance of life to smoothly proceed under a mild condition in vivo. This enzyme turns over in vivo, is produced in vivo depending on the situation and exhibits its catalytic function. [0004] At present, technologies for utilizing this enzyme in vitro have already been put into practical use or studied towards practical implementation. For example, a technology for utilizing an enzyme has been developed in various technical fields such as the production of a useful substance, the production, measurement or analysis of energy-related substance, the environmental preservation and the medical treatment. In relatively recent years, technologies regarding an enzyme cell which is one kind of a fuel cell (see, for example, JP-A-2004-71559), an enzyme electrode, an enzyme sensor (a sensor for measuring a chemical substance utilizing an enzymatic reaction) and the like have also been proposed. [0005] Since a chemical main body of this enzyme is a protein, the enzyme has properties that it is denatured by the degree of heat or pH. For that reason, enzymes have low stability in vitro as compared with other chemical catalysts such as metal catalysts. Accordingly, when an enzyme is utilized in vitro, it is important to allow the enzyme to work more stably in response to an environmental change and to maintain an activity thereof. [0006] When an enzyme is utilized in vitro, approaches such as a method for artificially modifying the nature or function of the enzyme itself and a method for devising the environment of a site where the enzyme works are employed. With respect to the former method, it is generally carried out that the base sequence of a gene encoding a protein is artificially modified, the thus modified gene is expressed in an organism such as Escherichia coli to produce an artificially mutated protein, and the protein mutant having functions and natures adapted to the use purpose is then subjected to separation (screening) (see, for example, JP-A-2004-298185). [0007] The “bilirubin oxidase” as referred to herein is an enzyme which catalyzes a reaction for oxidizing bilirubin into biliverdin and is one kind of enzyme belonging to a multicopper oxidase (a general term of an enzymes having plural copper ions in the active center). This enzyme has hitherto been widely used as an inspection reagent of liver function and the like (a measurement reagent of bilirubin in a blood serum) in the clinical laboratory examination. In recent years, this enzyme is also regarded as a catalyst for realizing an electrochemical four-electron reduction reaction of oxygen on a cathode side of the foregoing enzyme cell. [0008] Under circumstances where expectations for utilizing this bilirubin oxidase in vitro are rising, a technology for investigating the same enzyme having more excellent thermal stability (see, for example, JP-A-2006-68003) and a technology for stably maintaining the enzymatic activity of the same enzyme over a longer period of time (see, for example, JP-A-2000-83661) have also been proposed. [0009] In consideration of the utilization of a bilirubin oxidase in vitro, it is necessary that the thermal stability is more enhanced. However, this bilirubin oxidase involves a problem that the enzymatic activity is reduced to not more than 20% by heating at 60° C. for one hour. For example, in the field of an enzyme cell, since the bilirubin oxidase has the lowest thermal stability among a group of enzymes to be utilized and is remarkably low in the thermal stability as compared with enzymes on an anode side (for example, glucose dehydrogenase and diaphorase), it is not suitable to put an enzyme cell into practical use. Also, though there is a choice to substitute this bilirubin oxidase with laccase which is a multicopper oxidase, this laccase involves not only a problem regarding the heat resistance but a problem that the enzymatic activity at room temperature in a neutral pH region is remarkably low as compared with the bilirubin oxidase. SUMMARY [0010] Then, in consideration of the wide applicability of a bilirubin oxidase in vitro, it is desirable to provide a bilirubin oxidase mutant having prescribed levels or more of enzymatic activity and heat resistance of a bilirubin oxidase. [0011] According to an embodiment, there is provided a heat-resistant bilirubin oxidase mutant obtained by deletion, replacement, addition or insertion of at least one amino acid residue of the wild type amino sequence of SEQ. ID. No. 1 of a bilirubin oxidase derived from, an imperfect filamentous fungus, Myrothecium verrucaria (hereinafter referred to as “ M. verrucaria ”) so as to have enhanced heat resistance, and more favorably a heat-resistant bilirubin oxidase mutant having, for example, a denaturation temperature T m value of 72° C. or higher. Furthermore, there is provided a heat-resistant bilirubin oxidase mutant in which a residual activity after heating at 60° C. for one hour is 20% or more. For example, there is provided a heat-resistant bilirubin oxidase mutant having amino acid sequences of SEQ. ID. Nos. 2 to 45 and 57 to 67. As the foregoing imperfect filamentous fungus, for example, a strain of M. verrucaria NBRC (IFO) 6113 can be employed. Also, when the heat-resistant bilirubin oxidase mutant is expressed by using a yeast, Pichia methanolica as a host, it is possible to achieve abundant expression. [0012] Here, in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 2, glutamine at the 49th position from the N-terminus of the wild type amino acid sequence of SEQ. ID. No. 1 is replaced with lysine (hereafter abbreviated as “Q49K”). Similarly, in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 3, glutamine at the 72nd position is replaced with glutamic acid (hereafter abbreviated as “Q72E”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 4, valine at the 81st position is replaced with leucine (hereafter abbreviated as “V81L”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 5, tyrosine at the 121st position is replaced with serine (hereafter abbreviated as “Y121S”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 6, arginine at the 147th position is replaced with proline (hereafter abbreviated as “R147P”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 7, alanine at the 185th position is replaced with serine (hereafter abbreviated as “A185S”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 8, proline at the 210th position is replaced with leucine (hereafter abbreviated as “P210L”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 9, phenylalanine at the 225th position is replaced with valine (hereafter abbreviated as “F225V”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 10, glycine at the 258th position is replaced with valine (hereafter abbreviated as “G258V”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 11, alanine at the 264th position is replaced with valine (hereafter abbreviated as “A264V”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 12, aspartic acid at the 322nd position is replaced with asparagine (hereafter abbreviated as “D322N”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 13, asparagine at the 335th position is replaced with serine (hereafter abbreviated as “N335S”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 14, arginine at the 356th position is replaced with leucine (hereafter abbreviated as “R356L”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 15, proline at the 359th position is replaced with serine (hereafter abbreviated as “P359S”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 16, aspartic acid at the 370th position is replaced with tyrosine (hereafter abbreviated as “D370Y”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 17, valine at the 371st position is replaced with alanine (hereafter abbreviated as “V371A”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 18, proline at the 423rd position is replaced with leucine (hereafter abbreviated as “P423L”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 19, methionine at the 468th position is replaced with valine (hereafter abbreviated as “M468V”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 20, leucine at the 476th position is replaced with proline (hereafter abbreviated as “L476P”); and in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 21, valine at the 513rd position is replaced with leucine (hereafter abbreviated as “V513L”). Also, in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 57, alanine at the 103rd position is replaced with proline (hereafter abbreviated as “A103P”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 58, tyrosine at the 270th position is replaced with aspartic acid (hereafter abbreviated as “Y270D”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 59, serine at the 299th position is replaced with asparagine (hereafter abbreviated as “S299N”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 60, valine at the 381st position is replaced with leucine (hereafter abbreviated as “V381L”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 61, alanine at the 418th position is replaced with threonine (hereafter abbreviated as “A418T”); and in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 62, arginine at the 437th position is replaced with histidine (hereafter abbreviated as “R437H”). [0013] Also, in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 22, glutamine at the 49th position from the N-terminus of the wild type amino acid sequence of SEQ. ID. No. 1 is replaced with lysine, and valine at the 371st position is replaced with alanine (hereafter abbreviated as “Q49K/V371A”). Similarly, in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 23, glutamine at the 72nd position is replaced with glutamic acid, and proline at the 210th position is replaced with leucine (hereafter abbreviated as “Q72E/P210L”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 24, glutamine at the 72nd position is replaced with glutamic acid, and alanine at the 264th position is replaced with valine (hereafter abbreviated as “Q72E/A264V”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 25, valine at the 81st position is replaced with leucine, and arginine at the 147th position is replaced with proline (hereafter abbreviated as “V81L/R147P”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 26, valine at the 81st position is replaced with leucine, and proline at the 423rd position is replaced with leucine (hereafter abbreviated as “V81L/P423L”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 27, tyrosine at the 121st position is replaced with serine, and leucine at the 476th position is replaced with proline (hereafter abbreviated as “Y121S/L476P”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 28, alanine at the 185th position is replaced with serine, and glycine at the 258th position is replaced with valine (hereafter abbreviated as “A185S/G258V”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 29, proline at the 210th position is replaced with leucine, and alanine at the 264th position is replaced with valine (hereafter abbreviated as “P210L/A264V”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 30, phenylalanine at the 225th position is replaced with valine, and aspartic acid at the 322nd position is replaced with asparagine (hereafter abbreviated as “F225V/D322N”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 31, phenylalanine at 225th position is replaced by valine, and leucine at the 476th position is replaced with proline (hereafter abbreviated as “F225V/L476P”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 32, alanine at the 264th position is replaced with valine, and arginine at the 356th position is replaced with leucine (hereafter abbreviated as “A264V/R356L”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 33, alanine at the 264th position is replaced with valine, and leucine at the 476th position is replaced with proline (hereafter abbreviated as “A264V/L476P”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 34, aspartic acid at the 322nd position is replaced with asparagine, and methionine at the 468th position is replaced with valine (hereafter abbreviated as “D322N/M468V”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 35, asparagine at the 335th position is replaced with serine, and proline at the 423rd position is replaced with leucine (hereafter abbreviated as “N335S/P423L”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 36, arginine at the 356th position is replaced with leucine, and leucine at the 476th position is replaced with proline (hereafter abbreviated as “R356L/L476P”); and in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 37, valine at the 371st position is replaced with alanine, and valine at the 513rd position is replaced with leucine (hereafter abbreviated as “V371A/V513L”). [0014] Furthermore, in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 38, glutamine at the 49th position from the N-terminus of the wild type amino acid sequence of SEQ. ID. No. 1 is replaced with lysine, valine at the 371st position is replaced with alanine, and valine at the 513rd position is replaced with leucine (hereafter abbreviated as “Q49K/V371A/V513L”). Similarly, in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 39, glutamine at the 72nd position is replaced with glutamic acid, proline at the 210th position is replaced with leucine, and alanine at the 264th position is replaced with valine (hereafter abbreviated as “Q72E/P210L/A264V”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 40, valine at the 81st position is replaced with leucine, asparagine at the 335th position is replaced with serine, and proline at the 423rd position is replaced with leucine (hereafter abbreviated as “V81L/N335S/P423L”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 41, tyrosine at the 121st position is replaced with serine, aspartic acid at the 370th position is replaced with tyrosine, and leucine at the 476th position is replaced with proline (hereafter abbreviated as “Y121S/D370Y/L476P”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 42, alanine at the 185th position is replaced with serine, alanine at the 264th position is replaced with valine, and leucine at the 476th position is replaced with proline (hereafter abbreviated as “A185S/A264V/L476P”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 43, phenylalanine at the 225th position is replaced with valine, aspartic acid at the 322nd position is replaced with asparagine, and methionine at the 468th position is replaced with valine (hereafter abbreviated as “F225V/D322N/M468V”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 44, phenylalanine at the 225th position is replaced with valine, aspartic acid at the 370th position is replaced with tyrosine, and leucine at the 476th position is replaced with proline (hereafter abbreviated as “F225V/D370Y/L476P”); and in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 45, alanine at the 264th position is replaced with valine, arginine at the 356th position is replaced with leucine, and leucine at the 476th position is replaced with proline (hereafter abbreviated as “A264V/R356L/L476P”). Also, in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 63, alanine at the 264th position is replaced with valine, serine at the 299th position is replaced with asparagine, and leucine at the 476th position is replaced with proline (hereinafter abbreviated as “A264V/S299N/L476P”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 64, alanine at the 264th position is replaced with valine, valine at the 381st position is replaced with leucine, and leucine at the 476th position is replaced with proline (hereinafter abbreviated as “A264V/V381L/L476P”); in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 65, alanine at the 264th position is replaced with valine, alanine at the 418th position is replaced with threonine, and leucine at the 476th position is replaced with proline (hereinafter abbreviated as “A264V/A418T/L476P”); and in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 66, alanine at the 264th position is replaced with valine, arginine at the 437th position is replaced with histidine, and leucine at the 476th position is replaced with proline (hereinafter abbreviated as “A264V/R437H/L476P”). Furthermore, in a heat-resistant bilirubin oxidase mutant represented by SEQ. ID. No. 67, alanine at the 103rd position is replaced with proline, alanine at the 264th position is replaced with valine, tyrosine at the 270th position is replaced with aspartic acid, and leucine at the 476th position is replaced with proline (hereinafter abbreviated as “A103P/A264V/Y270D/L476P”). [0015] The term “residual enzyme activity after heating” as referred to herein may be referred to as “residual enzymatic activity” or “retention of enzymatic activity” and is a value representing a change in activity before and after an enzyme is subjected to prescribed heating. That is, the residual activity is a value of percentage representing how the activity value after heating has changed as compared with that before heating upon the measurement of enzymatic activity under the same condition. The condition of the term “heating” as referred to herein is a stationary treatment in a buffer solution at 60° C. for one hour, and a ratio of the foregoing enzymatic activity value before and after this heating is represented by percentage. [0016] Also, the term “denaturation temperature T m ” as referred to herein is a value determined by the measurement by differential scanning microcalorimetry. A temperature rise rate of an enzyme solution as a preparation in this measure was set up at 60° C. per hour. [0017] The heat-resistant bilirubin oxidase mutant according to an embodiment is able to maintain the enzymatic activity in a prescribed level or more even after heating. [0018] Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures. BRIEF DESCRIPTION OF THE FIGURES [0019] FIG. 1 is a diagram showing one example of thermal stabilization screening and showing the behavior of color generation of ABTS (one hour after the start of the reaction). [0020] FIG. 2 is a diagram showing a UV-vis spectrum of a recombinant BO mutant. DETAILED DESCRIPTION [0021] Next, specific examples according to an embodiment are described on the basis of the experimental results. Example 1 cDNA Cloning of BO Derived from M. verrucaria [0022] 1-1. Culture of M. verrucaria and Isolation of Messenger RNA: [0023] A strain of M. verrucaria NBRC (IFO) 6113 used in the present Example was purchased from National Institute of Technology and Evaluation, Department of Biotechnology. The obtained lyophilizate was suspended in a condensate (polypeptone: 0.5%, yeast extract: 0.3%, MgSO 4 ·7H 2 O: 0.1%), and this suspension was inoculated on a potato dextrose agar (PDA) plate (potato dextrose: 2.4%, agarose: 1.5%). As a result of culture at room temperature for 5 to 7 days, the surface of the PDA plate was covered by a white hypha. This was scraped by a spatula and preserved at −80° C. The yield of the bacterial cell was from 50 to 60 mg (wet weight) per PDA plate (diameter: 9 cm). [0024] A messenger RNA (hereinafter referred to a “mRNA”) was extracted as a total RNA (a mixture of mRNA, ribosomal RNA and transfer RNA). The total RNA was obtained in an amount of 100 μg (quantitatively determined by UV absorption) from about 100 mg of the lyophilizate powder of M. verrucaria , and a ¼ portion thereof was used as a template RNA of one reaction of the next reverse transcription PCR. [0025] 1-2. Preparation of BO Gene Fragment by Reverse Transcription PCR: [0026] The reverse transcription PCR was carried out by using a OneStep RT-PCR kit (manufactured by Qiagen Corporation) and using the foregoing total RNA as a template. A PCR primer to be used for the reverse transcription PCR was designed as shown in the following Table 1 on the basis of a previously reported base sequence of cDNA of BO. [0000] TABLE 1 N-Terminus side, HindIII (AAGCTT) site inserted 5′-GGGAAGCTTATGTTCAAACACACACTTGGAGCTG-3′ (SEQ. ID. No. 46) C-Terminus side, XbaI (TCTAGA) site inserted 5′-GGGTCTAGACTCGTCAGCTGCGGCGTAAGGTCTG-3′ (SEQ. ID. No. 47) [0027] As a result of agarose gel electrophoresis of the resulting PCR product, a strong band could be verified in the vicinity of 1,700 bp. In view of the size of 1,700 bp, this fragment was estimated to be an amplified fragment containing the desired BO gene, and therefore, this fragment was cut out from the agarose gel slab and used in a next step. [0028] 1-3. Integration of BO Gene Fragment into pYES2/CT Vector: [0029] The obtained amplified fragment of 1,700 bp was digested by restriction enzymes HindIII and XbaI and then coupled with a pYES2/CT plasmid vector (manufactured by Invitrogen Corporation) as digested by the same enzymes. On that occasion, an alkaline phosphatase derived from Calf intestine (manufactured by Takara Bio Inc.) was used for the dephosphorylation of a 5′-protruding end of the pYES2/CT vector by the restriction enzyme treatment, and T4 DNA ligase (manufactured by Takara Bio Inc.) was used for a coupling reaction between the inserted fragment and the pYES2/CT vector, respectively. [0030] A strain of E. coli TOP10 (manufactured by Invitrogen Corporation) was transformed by the thus obtained reaction product and inoculated on an LB/Amp agar plate medium (having a composition as shown in Table 2). After culturing overnight, a colony of a transformant having drug resistance to ampicillin was obtained. This was cultured overnight on 3 mL of an LB/Amp medium, and the plasmid vector was isolated from the resulting bacterial cell. [0000] TABLE 2 Tryptophan 1% Yeast extract 0.5%   Sodium chloride 1% Ampicillin 0.005%    [0031] As a result of examining the base sequence of the inserted portion containing a BO gene of the resulting plasmid vector, it was found to be SEQ. ID. No. 48. [0032] The base sequence represented in SEQ ID. No. 48 is 1,719 bp and is corresponding to 572 amino acid residues. On the other hand, a BO derived from M. verrucaria of a maturation type is constituted of 534 amino acid residues (SEQ. ID. No. 1). The 38 amino acid residues corresponding to a difference therebetween exists on the N-terminus side and are a signal peptide for governing the secretion of a protein existing on the C-terminus side. After translation, the portion is cleaved at the time of secretion. [0033] 1-4. Insertion of AAA Sequence: [0034] Next, with respect to the plasmid vector as prepared in 1-3, a part of the base sequence thereof was modified so as to increase the expression amount of the recombinant protein. Concretely, three bases on the upstream side (5′-side) relative to a start codon (ATG) were changed as follows. [0000] TABLE 3 Before modification: 5′- . . . ATTAAG AAATG TTCAAAC . . . -3′ (SED. ID. No. 49) After modification: 5′- . . . ATTAAG AAAATG TTCAAAC . . . -3′ (SED. ID. No. 50) [0035] The change of these three bases was carried out by a Quick-Change mutagenesis kit (manufactured by Stratagene Corporation) by using a PCR primer as shown in the following Table 4. The detailed experimental procedures followed those in a manual attached to the product. [0000] TABLE 4 N-Terminus side: 5′-CTATAGGGAATATTAAGAAA ATG TTCAAACACACACTTG-3′ (SED. ID. No. 51) C-Terminus side: 5′-CAAGTGTGTGTTTGAA CAT TTTCTTAATATTCCCTATAGTG-3′ (SED. ID. No. 52) [0036] The verification of the base sequence was carried out in the entire region of the BO gene including the changed sites. As a result, it was verified that the base sequence was changed as designed. The plasmid vector after changing the sequence is hereinafter referred to as “pYES2/CT-BO vector”. Example 2 Construction of Secretion Expression System of Recombinant BO by S. cerevisiae [0037] 2-1. Transformation of S. cerevisiae by pYES2/CT-BO Vector: [0038] Next, the transformation of S. cerevisiae was carried out by using the foregoing pYES2/CT-BO vector. As S. cerevisiae , a strain of INVSc1 (manufactured by Invitrogen Corporation) which is marketed along with the pYES2/CT vector was used. Here, the transformation of S. cerevisiae was carried out by a lithium acetate method. With respect to the detailed experimental procedures, a manual attached to the pYES2/CT vector was made by reference. For selecting the transformed yeast, an SCGlu agar plate medium (having a composition as shown in Table 2) was used. [0000] TABLE 5 Yeast nitrogen base (YNB) 0.17% (NH 4 ) 2 SO 4  0.5% L-Arginine 0.01% L-Cysteine 0.01% L-Leucine 0.01% L-Lysine 0.01% L-Threonine 0.01% L-Tryptophan 0.01% L-Aspartic acid 0.005%  L-Histidine 0.005%  L-Isoleucine 0.005%  L-Methionine 0.005%  L-Phenylalanine 0.005%  L-Proline 0.005%  L-Serine 0.005%  L-Tyrosine 0.005%  L-Valine 0.005%  Adenine 0.01% D-Glucose   2% Agarose   2% [0039] 2-2. Secretion Expression of Recombinant BO: [0040] The colony of the transformant of S. cerevisiae by the pYES2/CT-BO vector was inoculated on 15 mL of an SCGlu liquid medium and cultured with shaking at 30° C. for from 14 to 20 hours. The resulting bacterial cell was once precipitated by centrifugation (1,500×g at room temperature for 10 minutes). [0041] Here, after discarding the SCGlu liquid medium, the resulting bacterial cell was added in 50 mL of an SCGal medium (having a composition as shown in Table 6) such that a turbidity (OD 600 ) was about 0.5. This was cultured with shaking at 25° C. for from 10 to 14 hours. After the culture, the bacterial cell was removed by centrifugation, the residual culture solution was concentrated to a degree of about 5 mL and dialyzed against a 20 mM sodium phosphate buffer solution (pH: 7.4). [0000] TABLE 6 Yeast nitrogen base (YNB) 0.17% (NH 4 ) 2 SO 4  0.5% L-Arginine 0.01% L-Cysteine 0.01% L-Leucine 0.01% L-Lysine 0.01% L-Threonine 0.01% L-Tryptophan 0.01% L-Aspartic acid 0.005%  L-Histidine 0.005%  L-Isoleucine 0.005%  L-Methionine 0.005%  L-Phenylalanine 0.005%  L-Proline 0.005%  L-Serine 0.005%  L-Tyrosine 0.005%  L-Valine 0.005%  Adenine 0.01% D-Galactose   2% Raffinose   1% Glycine   1% CuSO 4 •5H 2 O 0.003%  [0042] The purification of the recombinant BO was carried out by Ni-NTA affinity chromatography (His-trap HP (1 mL), manufactured by Amersham Biosciences K.K.). The purification method followed that in a manual attached to the product. The recombinant BO obtained after the purification was verified to have a purity of 100 by SDS-PAGE or the like. The yield of the resulting recombinant BO was calculated into 1L-culture and found to be 0.36 mg. Example 3 Thermal Stabilization Screening of Recombinant BO by Evolutionary Molecular Engineering Method [0043] Next, the recombinant BO was subjected to thermal stabilization screening by an evolutionary molecular engineering method. Concretely, the insertion of random mutation using Error-prone PCR, the preparation of a BO gene library as a transformant, the transformation of S. cerevisiae by the BO mutant gene library and the thermal stabilization screening by a 96-well plate were carried out. [0044] 3-1. Insertion of Random Mutation using Error-Prone PCR: [0045] The insertion of random mutation by Error-prone PCR was carried out by using the pYES2/CT-BO vector as a template. The PCR primer on the N-terminus side as used herein was designed so as to contain only one BglII side (AGATCT) existing in the downstream of the 218 base pairs relative to the start codon. Also, the C-terminus side was designed in the following manner so as to contain the XbaI site (TCTAGA) (see Table 7). [0000] TABLE 7 N-Terminus side, BglII (AGATCT) site inserted 5′-GTAACCAATCCTGTGAATGGACAAG AGATCT GG-3′ (SEQ. ID. No. 53) C-Terminus side, XbaI (TCTAGA) site inserted 5′-GGGATAGGCTTACCTTCGAAGGGCCC TCTAGA CTC-3′ (SEQ. ID. No. 54) [0046] The Error-prone PCR was carried out by a GeneMorph PCR mutagenesis kit (manufactured by Stratagene Corporation) by using this primer. With respect to the reaction condition, a manual attached to the same kit was made by reference. [0047] As a result of agarose gel electrophoresis of the resulting PCR product, a PCR fragment of about 1,500 bp could be obtained. The frequency of mutation as calculated from the yield of the resulting PCR product was 1.5 sites per 1,000 bp. With respect to the calculation method, a manual attached to the same kit was made by reference. [0048] 3-2. Preparation of BO Gene Library of Mutant: [0049] With respect to the BO gene fragment having mutation randomly inserted thereinto as prepared above in 3-1, integration of the pYES2/CT-BO vector into the BglII-XbaI sites and transformation of a strain of E. coli TOP10 were carried out in the same manner as described above in 1-3. Here, a plasmid library including about 6,600 transformant colonies, namely about 6,600 kinds of transformant genes. [0050] 3-3. Transformation of S. cerevisiae by Transformant BO Gene Library: [0051] The transformation of a strain of S. cerevisiae INVSc1 (manufactured by Invitrogen Corporation) by the transformant BO gene library was carried out in the same manner as described above in 3-2. A competent cell of S. cerevisiae INVSc1 was prepared by a lithium acetate method. The resulting transformant library was subjected to thermal stabilization screening by using a 96-well plate. [0052] 3-4. Thermal Stabilization Screening Experiment using 96-Well Plate: [0053] A 150-mL portion of an SCGlu medium was poured out into a 96-well plate. One colony of the thus prepared transformant yeast library was inoculated in each well. This was cultured with shaking at 27° C. for from 20 to 23 hours. After this culture, the visual observation revealed that the turbidity of the respective wells became substantially constant. [0054] At this stage, every 96-well plate was once subjected to centrifugation (1,500×g at 20° C. for 10 minutes), thereby once precipitating the bacterial cell. The SCGlu medium was completely removed in such a manner that the bacterial cell precipitated on the bottom of each well was not disturbed. A 180-mL portion of an SCGal medium was poured out thereinto, and the bacterial cell was further cultured with shaking at 27° C. for 8 hours. After this culture, the centrifugation (1,500×g at 20° C. for 10 minutes) was again carried out to precipitate the bacterial cell. 100 mL of this supernatant was transferred into a separate, new 96-well plate. Here, when carrying out heating, a sample solution on this 96-well plate was sealed by a cellophane tape and then allowed to stand in a dry oven at 80° C. for 15 minutes. After heating, the sample solution was rapidly cooled on an ice bath for 5 minutes and then allowed to stand at room temperature for 15 minutes. An equal amount of a 20 mM ABTS solution (100 mM Tris-HCl, pH: 8.0) was mixed therewith. The situation that the solution in the well was colored green with the progress of reaction of ABTS was observed until one hour elapsed after the start of the reaction. Ones exhibiting strong coloration as compared with the wild type as a comparison were picked up, and bacterial cells corresponding thereto were preserved as 20 glycerol stocks at −80° C. [0055] FIG. 1 shows one example of thermal stabilization screening. FIG. 1 shows the behavior of color generation of ABTS one hour after the start of the reaction. All of central two columns (6th and 7th columns from the left side) are concerned with the wild type recombinant BO as a comparison, in which the 6th column is concerned with one having been subjected to heating similar to other wells. The 7th column is concerned with the comparison in the case of the wild type recombinant BO not having been subjected to heating. [0056] It is noted from FIG. 1 that the wells surrounded by a square cause strong color generation as compared with any of the wild types in the 6th column. It is thought that in these wells, a BO mutant having enhanced thermal stability is expressed as compared with the wild type recombinant BO. [0057] In this Example 3, the thermal stabilization screening as described in 3-4 was performed with respect to 4,000 samples in total in 50 sheets of a 96-well plate, and 26 transformant yeasts which are thought to have expressed the heat-resistant BO mutant were chosen. [0058] Plasmid vectors were extracted with the obtained 26 transformant yeasts and subjected to an analysis of base sequence of the BO gene region. As a result, it became clear that the following 26 kinds of mutations were inserted into the BO gene. That is, mutations of the foregoing abbreviations Q49K, Q72E, V81L, Y121S, R147P, A185S, P210L, F225V, G258V, A264V, D322N, N335S, R356L, P359S, D370Y, V371A, P423L, M468V, L476P, V513L, A103P, Y270D, S299N, V381L, A418T and R437H were verified. Example 4 Abundant Expression by Heat-Resistant Mutant Pichia methanolica [0059] In the following, in order to achieve abundant expression of the 26 kinds of heat-resistant mutant candidacies discovered by the thermal stabilization screening, the construction of secretion expression system of recombinant BO using a yeast Pichia methanolica (hereinafter referred to as “ P. methanolica ”) was newly performed, thereby attempting to achieve abundant expression of the wild type and heat-resistant mutant candidacies. [0060] 4-1. Preparation of pMETaB-BO Vector and Transformation of P. methanolica by this Vector: [0061] First of all, an expression vector to be used in an expression system of P. methanolica was prepared. Since a secretion signal: α-factor derived from S. cerevisiae is contained in a pMETaB vector (manufactured by Invitrogen Corporation), a gene corresponding to a maturation BO was inserted into its downstream. The amplification of the maturation BO gene region by PCR was carried out by using the pYES2/CT-BO vector as a template and using primers as shown in the following Table 8. [0000] TABLE 8 N-Terminus side, EcoRI (GAATTC) site inserted 5′-GGGAATTCTTGCCCAGATCAGCCCACAGTATC-3′ (SEQ. ID. No. 55) C-Terminus side, Termination codon, SpeI (ACTAGT) site inserted 5′-GGGACTAGTCACTCGTCAGCTGCGGCGTAAGG-3′ (SEQ. ID. No. 56) [0062] The obtained amplified fragment of 1,500 bp was digested by restriction enzymes EcoRI and SpeI and then coupled with a pMETaB vector as digested by the same enzymes. On the occasion of this coupling reaction, the reaction product was subjected to the same treatment as that described above in 1-3. With respect to the thus prepared BO gene region-containing pMETaB vector (hereinafter referred to as “pMETaB-BO vector”), the verification of the base sequence of the inserted BO gene portion was carried out. In the case of the BO mutant, mutations were inserted into the thus prepared pMETaB-BO vector by QuickChange Mutagenesis Kits (manufactured by Invitrogen Corporation). The subsequent operations were similarly carried out irrespective of the wild type and the mutant. [0063] In addition to the foregoing pMETaB-BO vectors of the wild type and 26 kinds of heat-resistant mutant candidacies, a pMETaB-BO vector of a multiple mutant obtained by combining two, three or four of the 26 kinds of heat-resistant mutant candidacies was similarly prepared and verified with respect to the base sequence. [0064] The transformation of P. methanolica by all of the thus prepared pMETaB-BO vectors was carried out. A strain of PMAD11 (manufactured by Invitrogen Corporation) was used as P. methanolica . The transformation followed a method described in a manual attached to the pMETaB vector. The selection of the transformed yeast was carried out on an MD agar plate medium (having a composition as shown in Table 9). Competencies of this reaction were all up to 10/1 μg DNA and were substantially coincident with the values described in the manual. [0000] TABLE 9 Yeast nitrogen base (YNB) 1.34% Biotin 0.00004%   D-Glucose   2% Agarose  1.5% [0065] 4-2. Abundant Expression of Recombinant BO by P. methanolica: [0066] The colony of the transformant yeast on an MD medium as obtained 5 to 7 days after the transformation was cultured overnight on 3 mL of a BMDY medium (having a composition as shown in Table 10). A part of the resulting culture solution was again developed on an MD agar plate medium. A white purified colony obtained 2 to 3 days after this was used for the abundant expression in the next item. [0000] TABLE 10 Yeast extract 1% Peptone 2% Potassium phosphate buffer solution (pH: 6.0) 100 mM Yeast nitrogen base (YNB) 1.34%   Biotin 0.00004%     D-Glucose 2% [0067] Next, an operation of the abundant expression of recombinant BO by P. methanolica was carried out. The purified colony of the transformant yeast was inoculated on 50 mL of a BMDY liquid medium and cultured with shaking at 30° C. overnight. At that time, the OD 600 was found to be from 2 to 5. The thus obtained bacterial cell was once precipitated by centrifugation (1,500×g at room temperature for 10 minutes), the BMDY liquid medium was removed, and only the bacterial cell was then suspended in 50 to 100 mL of a BMMY liquid medium (having a composition as shown in Table 11). The suspension was cultured with shaking at 27° C. for 24 hours. Thereafter, methanol was added such that a final concentration was 0.5%, and the mixture was further cultured under the same condition for 24 hours. After performing this until elapsing 96 hours, the bacterial cell was removed by centrifugation, and the residual culture solution was concentrated to a degree of about 5 to 10 mL and dialyzed against a 50 mM Tris-HCl buffer (pH: 7.6). [0000] TABLE 11 Yeast extract 1% Peptone 2% Potassium phosphate buffer solution (pH: 6.0) 100 mM Yeast nitrogen base (YNB) 1.34%   Biotin 0.00004%     Methanol 0.5%   CuSO 4 •5H 2 O 0.003%    [0068] 4-3. Purification of Recombinant BO: [0069] Subsequently, the purification of the recombinant BO by anion-exchange chromatography was carried out. A crude solution containing the recombinant BO as prepared in the preceding step was purified by using an anion-exchange column (HiTrap Q HP, bed volume: 5 mL, manufactured by GE Healthcare Bioscience Corp.). With respect to the purification condition, a previous report ( Biochemistry, 38, 3034-3042 (1999)) was made by reference. [0070] Next, the purification of the recombinant BO by hydrophobic chromatography was carried out. A column used for the hydrophobic chromatography is a Toyopearl Butyl-650 M column (100 mL, 20 mm×20 cm, manufactured by Tosoh Corporation). With respect to the purification condition, a previous report ( Biochemistry, 44, 7004-7012 (2005)) was made by reference. A UV-vis spectrum of the recombinant BO (A246V) obtained after the purification is shown in FIG. 2 . [0071] The spectral pattern of A264V as shown in FIG. 2 was completely coincident with that of a recombinant BO by P. pastris in a previous report ( Protein Expression Purif., 41, 77-83 (2005)). [0072] A final yield of the abundant culture by P. methanolica was 11.7 mg/1 L-culture at maximum. [0073] 4-4. Evaluation of Heat Resistance: [0074] Next, a recombinant BO by P. methanolica and a commercially available BO (manufactured by Amano Enzyme Inc.) were evaluated with respect to the heat resistance. The evaluation of the heat resistance was performed by the comparison in the residual activity after heating. For the measurement of the BO activity, ABTS was used as a substrate, a change in the absorbance at 730 nm with the progress of reaction (derived from an increase of the reaction product of ABTS) was followed. The measurement condition is shown in Table 12. During the activity measurement, the BO concentration was adjusted such that the change in the absorbance at 730 nm was from about 0.01 to 0.2 per minute. The reaction was started by adding an enzyme solution (5 to 20 μL) in an ABTS-containing phosphate buffer solution (2,980 to 2,995 μL). [0000] TABLE 12 Buffer solution 46.5 mM sodium phosphate aqueous solution (pH: 7.0) ABTS concentration   2 mM (final concentration) O 2 concentration Saturated with air (210.M, 25° C.) Reaction temperature 25° C. [0075] With respect to the 26 kinds in total of the heat-resistant BO mutant candidacies expressed by P. methanolica (Q49K, Q72E, V81L, Y121S, R147P, A185S, P210L, F225V, G258V, A264V, D322N, N335S, R356L, P359S, D370Y, V371A, P423L, M468V, L476P, V513L, A103P, Y270D, S299N, V381L, A418T and R437H) and a multiple mutant obtained by combining two, three or four of them, a heat resistance experiment was carried out. With respect to the heating of each enzyme solution, a method of rapidly moving 150 mL of an enzyme solution (100 mM potassium phosphate buffer (pH: 6.0)) as poured out into a 500-mL tube in an ice bath onto a heat block set up at 60° C., allowing it to stand for a fixed time and then rapidly again returning in an ice bath was employed. The results of this heat resistance verification experiment are summarized in Table 13. [0076] 4-5. Measurement of Denaturation Temperature: [0077] The denaturation temperature T m of the 55 kinds of heat-resistant BO mutants having been subjected to evaluation of heat resistance was measured by differential scanning calorimetry (hereinafter referred to as “DSC”). VP-DSC as manufactured by MicroCal, LLC was used for the DSC. An enzyme solution was used in an amount of from 2.0 to 2.5 mg/mL, and the temperature rise was carried out at a rate of 60° C. per hour. The results are summarized along with the heat resistance verification experiment of the activity in Table 13. [0000] TABLE 13 Residual activity & denaturation Triple mutant or temperature Single mutant Double mutant quartet mutant 80% or more & Y121S/L476P, A264V/R356L, Q49K/V371A/V513L, 77° C. or higher A264V/L476P, D322N/M468V Y121S/D370Y/L476P, A185S/A264V/L476P, K225V/D322N/M468V, A264V/R356L/L476P, A264V/S299N/L476P, A264V/V381L/L476P, A264V/A418T/L476P, A264V/R437H/L476P, A103P/A264V/V270D/L476P 50% or more & Q72E, V81L, Y121S, Q72E/P210L/A264V, 75° C. or higher F225V, A264V, D322N, V81L/N335S/P423L, R356L, P359S, D370Y, F225V/D370Y/L476P P423L, M468V, L476P, A103P, S299N, V381L, A418T, R437H 20% or more & Q49K, R147P, A185S, Q49K/V371A, Q72E/P210L, 72° C. or higher P210L, G258V, N335S, Q72E/A264V, V81L/R147P, V371A, V513T, V270D V81L/P423L, A185S/G258V, P210L/A264V, F225V/D322N, F225V/L476P. N335S/P423L, R356L/L476P, V371A/V513L Less than 20% & Wild type, commercial lower than 72° C. product [0078] The heat-resistant bilirubin oxidase mutant according to the embodiment can be, for example, utilized as a catalyst for realizing an electrochemical four-electron reduction reaction of oxygen in a fuel cell using an electrode having an enzyme immobilized therein, especially on a cathode side of the enzyme cell. [0079] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.

A heat-resistant bilirubin oxidase mutant is disclosed. The bilirubin oxidase is obtained by deletion, replacement, addition or insertion of at least one amino acid residue of a wild type amino sequence of SEQ. ID. No. 1 of a bilirubin oxidase derived from an imperfect filamentous fungus, Myrothecium verrucaria.

[0001] This is a continuation of PCT application Serial No. PCT/GB99/01344 filed on Apr. 28. 1999 and PCT application Serial No. PCT/GB99/01347 filed on Apr. 28. 1999. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to cellular mobile communication networks, for example Code Division Multiple Access (CDMA) cellular networks. [0004] 2. Description of the Prior Art [0005] [0005]FIG. 1 of the accompanying drawings shows parts of a cellular mobile telecommunication network according to the Telecommunication Industries Association (TIA)/Electronic Industries Association (EIA) Standard TIA/EIA/IS-95 of October 1994 (hereinafter “IS95”). Each of three base transceiver stations (BTSs) 4 (BTS 1 , BTS 2 and BTS 3 ) is connected via a fixed network 5 to a base station controller (BSC) 6 , which is in turn connected to a mobile switching center (MSC) 7 . The BSC 6 serves to manage the radio resources of its connected BTSs 4 , for example by performing hand-off and allocating radio channels. The MSC 7 serves to provide switching functions and coordinates location registration and call delivery. [0006] Each BTS 4 serves a cell 8 . When a mobile station (MS) 10 is in a so-called “soft hand-off” (SHO) region 9 where two or more cells overlap, a mobile station can receive transmission signals (downlink signals) of comparable strength and quality from the respective BTSs of the overlapping cells. Transmission signals (uplink signals) produced by the mobile station (MS) can also be received at comparable strengths and qualities by these different BTSs when the mobile station is in the SHO region 9 . [0007] [0007]FIG. 2 of the accompanying drawings shows a situation where the MS 10 is located within the SHO region 9 , and is transmitting such uplink signals that are being received by plural BTSs 4 . According to the IS95 standard, a BTS 4 that receives such an uplink signal from the MS 10 relays the signal to the BSC 6 via a dedicated connection line of the fixed network 5 . At the BSC 6 , one of the relayed signals is selected based on a comparison of the quality of each of the received signals, and the selected signal is relayed to the MSC 7 . This selection is referred to as Selection Diversity. [0008] Similarly, FIG. 3 of the accompanying drawings shows a situation where the MS 10 is located within the SHO region 9 and is receiving downlink signals from plural BTSs 4 . According to the IS95 standard, downlink signals received by the BSC 6 from the MSC 7 are relayed to all BTSs 4 involved in the soft hand-off via respective connection lines of the fixed network 5 , and subsequently transmitted by all the BTSs 4 to the MS 10 . At the MS 10 the multiple signals may be combined, for example, by using maximum ratio combination (MRC), or one of them may be selected based on the signal strength or quality, i.e. using Selection Diversity as for the uplink case. [0009] In contrast to, for example, Global System for Mobile Communication (GSM) networks, in CDMA networks each BTS 4 transmits at the same frequency. Consequently, careful control of transmission power must be maintained to minimize interference problems. [0010] Signals are transmitted as a succession of frames according to the IS95 standard. As FIG. 4 of the accompanying drawings shows, each frame is of duration 20 ms, and comprises sixteen 1.25 ms time slots. In each time slot several bits of user data and/or control information can be transmitted. [0011] Power control of transmissions from the MS 10 to the BTSs 4 (uplink power control) in IS95 is achieved as follows. When a BTS 4 receives a signal from the MS 10 it determines whether a predetermined property of the received signal (for example absolute signal level, signal to noise ratio (SNR), signal-to-interference ratio (SIR), bit error rate (BER) or frame error rate (FER)) exceeds a pre-selected threshold level. Based on this determination, the BTS 4 instructs the MS 10 either to reduce or to increase its transmission power in the next time slot. [0012] For this purpose, two bits in every time slot of a pilot channel (PCH) from the BTS 4 to the MS 10 are allocated for uplink power control (see FIG. 4). Both bits have the same value, and accordingly will be referred to hereinafter as the “power control bit” (or PCB) in the singular. The power control bit is assigned a value of zero by the BTS 4 if the MS 10 is required to increase transmission power by 1 dB, and a value of one if the MS 10 is required to decrease transmission power by 1 dB. The BTS 4 is not able to request directly that the MS 10 maintain the same transmission power; only by alternately transmitting ones and zeros in the power control bit is the transmission power maintained at the same level. [0013] When the MS 10 is in a SHO region 9 , the MS 10 is required to make a decision on whether to increase or to decrease uplink transmission power based on a plurality of power control bits received respectively from the BTSs 4 involved in the soft hand-off. Consequently, an OR function is performed on all the power control bits. If the result of this OR function is zero then the MS 10 will increase power on uplink transmissions, and if the result is one then the MS 10 will decrease power on uplink transmissions. In this way, uplink transmission power is only increased if all BTSs 4 ask for an increase. [0014] Power control of transmissions from the BTS 4 to the MS 10 (downlink power control) in IS95 is achieved as follows. When the MS 10 receives a downlink signal from a BTS 4 (or from each of a plurality of BTSs 4 in soft hand-off operation) via a traffic channel (TCH), the FER of that signal is calculated by the MS 10 . The FER reflects the degree to which the traffic-channel signal has been corrupted by, for example, noise. This FER is then relayed by the MS 10 to the BTS 4 which transmitted the downlink signal concerned, and the BTS 4 uses this FER to decide whether to make any change to its downlink transmission power. [0015] The soft hand-off system described above is effective in improving signal transmission between the MS 10 and the network when the MS 10 is located in regions of cell overlap near the boundaries of the individual cells. Signal quality in these regions when using a single BTS 4 may be relatively poor, but by making use of more than one BTS 4 the quality may be substantially improved. [0016] However, the IS95 soft hand-off system has the disadvantage of increasing signal traffic in the cellular network since it is necessary to transmit downlink signals carrying the same data and/or control information to the MS 10 from every BTS 4 involved in the soft hand-off. This duplication of transmissions is undesirable because each transmission is potentially a source of interference to other transmissions in the network. [0017] For example, the downlink-power control method aims at ensuring that the MS 10 receives a useful downlink signal from every one of the BTSs 4 involved in the soft hand-off. In the event that the downlink signal from one of the BTSs is undergoing a deep fade, the MS 10 will instruct the BTS concerned to increase its downlink transmission power significantly. However, in this case the BTS concerned will inevitably cause greater interference to other transmissions taking place in its cell and in neighboring cells. This problem may be exacerbated if, as in the IS95 standard, only one PCB is allocated in common for downlink power control to all of the BTSs involved in the soft hand-off. In this case, not only does the BTS that is experiencing a deep fade increase its downlink transmission power significantly, but also every other one of the BTSs involved in the soft hand-off increases its downlink transmission power, significantly increasing the interference within the cellular network as a whole. [0018] Therefore, it is desirable to reduce interference in the cellular network associated with the soft hand-off operation. It is also desirable to reduce interference in cellular networks in other situations in which a mobile station is in communications range of more than one base transceiver station. SUMMARY OF THE INVENTION [0019] According to a first aspect of the present invention there is provided a cellular mobile communications network including: a candidate base transceiver station identifying unit operable, when a mobile station of the network is capable of receiving a downlink signal from a plurality of base transceiver stations of the network, to identify at least two different candidate base transceiver station selections. Each such selection specifying one or more base transceiver stations of the plurality for possible use in transmitting a subsequent such downlink signal to the mobile station. A network interference determining unit operable, for each of the candidate selections, to produce a measure of the network interference that would be caused by the base transceiver station(s) specified in that candidate selection transmitting the subsequent downlink signal to the mobile station. A decision unit operable, in dependence upon the network-interference measures, to decide which one of the candidate selections is to be used to transmit the subsequent downlink signal to the mobile station, so as to tend to reduce network interference arising from the transmission of that downlink signal. [0020] According to a second aspect of the present invention there is provided a mobile station, for use in a cellular mobile communications network, including: a candidate base transceiver station identifying unit operable, when the mobile station is capable of receiving a downlink signal from a plurality of base transceiver stations of the network, to identify at least two different candidate base transceiver station selections. Each such candidate selection specifying one or more base transceiver stations of the plurality for possible use in transmitting a subsequent such downlink signal to the mobile station. A network interference determining unit operable for each of the candidate selections, to produce a measure of the network interference that would be caused by the base transceiver station(s) specified in that selection transmitting the subsequent downlink signal to the mobile station. A decision unit operable, in dependence upon the network-interference measures, to decide which one of the candidate selections should be used to transmit the subsequent downlink signal to the mobile station, so as to tend to reduce network interference arising from the transmission of that downlink signal. [0021] According to a third aspect of the present invention there is provided a base transceiver station, for use in a cellular mobile communications network, including: A candidate base transceiver station identifying unit operable, when a mobile station of the network is capable of receiving a downlink signal from a plurality of base transceiver stations of the network including the base transceiver station, to identify at least two different candidate base transceiver station selections. Each such candidate selection specifying one or more base transceiver stations of the plurality for possible use in transmitting a subsequent such downlink signal to the mobile station. A network interference determining unit operable, for each of the candidate selections, to produce a measure of the network interference that would be caused by the base transceiver station(s) specified in that selection transmitting the subsequent downlink signal to the mobile station. A decision unit operable, in dependence upon the network-interference measures, to decide which one of the candidate selections should be used to transmit the subsequent downlink signal to the mobile station, so as to tend to reduce network interference arising from the transmission of that downlink signal. [0022] According to a fourth aspect of the present invention there is provided a base station controller, for use in a cellular mobile communications network, including: A candidate base transceiver station identifying unit operable, when a mobile station of the network is capable of receiving a downlink signal from a plurality of base transceiver stations of the network, to identify at least two different candidate base transceiver station selections. Each such candidate selection specifying one or more base transceiver stations of the plurality for possible use in transmitting a subsequent such downlink signal to the mobile station. A network interference determining unit operable, for each of the candidate selections, to produce a measure of the network interference that would be caused by the base transceiver station(s) specified in that selection transmitting the subsequent downlink signal to the mobile station. A decision unit operable, in dependence upon the network-interference measures, to decide which one of the candidate selections to use to transmit the subsequent downlink signal to the mobile station, so as to tend to reduce network interference arising from the transmission of that downlink signal. [0023] According to a fifth aspect of the present invention there is provided a communications method for use in a cellular mobile communications network, including: when a mobile station of the network is capable of receiving a downlink signal from a plurality of base transceiver stations of the network, identifying at least two different candidate base transceiver station selections, each such selection specifying one or more base transceiver stations of the plurality for possible use in transmitting a subsequent such downlink signal to the mobile station; producing, for each of the candidate selections, a measure of the network interference that would be caused by the base transceiver station(s) specified in that selection transmitting the subsequent downlink signal to the mobile station; and deciding, in dependence upon the network-interference measures, which one of the said candidate selections to use to transmit that subsequent downlink signal to the mobile station, so as to tend to reduce network interference arising from the transmission of that downlink signal. [0024] In one embodiment of the first to fifth aspects of the invention, the candidate selections may include, for each BTS of the plurality, a selection in which just that BTS is specified, as well as a further selection in which all the BTSs of the plurality are specified. It is not essential for the candidate selections to include selections specifying only one BTS. For example, if there are three BTSs involved in a soft hand-off operation, the selections could be BTS 1 +BTS 2 , BTS 2 +BTS 3 , BTS 3 +BTS 1 , and BTS 1 +BTS 2 +BTS 3 . It is also not essential for the candidate selections to include a selection specifying all the BTSs involved in the soft hand-off. Furthermore, the transmission powers for the BTSs specified in a particular selection can be set to any suitable combination of values capable of facilitating adequate reception of the downlink signal at the subject mobile station. Thus, for example, two or more candidate selections could specify the same BTSs but specify different respective sets of transmission powers for the selections. In other words, two candidate selections could differ from one another only in respect of the transmission powers of the (same) specified BTSs. [0025] According to a sixth aspect of the present invention there is provided a mobile station for use a cellular mobile communications network, including: A base transceiver station decision unit operable, when the mobile station is capable of receiving a downlink signal from a plurality of base transceiver stations of the network, to determine that at least one of the base transceiver stations of the plurality is not to transmit a subsequent such downlink signal to the mobile station; and a base transceiver station informing unit operable to inform the base transceiver stations of the plurality of the determination made by the base transceiver station decision unit using one or more uplink signals transmitted by the mobile station to such base transceiver stations. [0026] According to a seventh aspect of the present invention there is provided a base transceiver station for use in a cellular mobile communications network, including: A receiver for receiving uplink signals from a mobile station of the network, one or more of which uplink signals includes, when the mobile station is capable of receiving a downlink signal from a plurality of base transceiver stations of the network including the base transceiver station, base transceiver station selection information specifying that at least one of the base transceiver stations of the plurality is not to transmit a subsequent such downlink signal to the mobile station; and a disabling unit operable to process such base transceiver station selection information and to prevent the base transceiver station from transmitting such a subsequent downlink signal if the received base transceiver station selection information specifies that the base transceiver station is not to transmit the subsequent downlink signal. [0027] The sixth and seventh aspects of the present invention are not limited to downlink transmission selection for the purpose of interference reduction. Embodiments of these aspects of the invention can be used in any situation in which it is desired to prevent at least one BTS in communications range of a mobile station from transmitting a downlink signal to that mobile station. [0028] According to an eighth aspect of the present invention there is provided a mobile station, for use in a cellular mobile communications network, including: a transmitter for transmitting uplink signals to a base transceiver station of the network and a signal information processor connected to the transmitter and operable, during a soft hand-off operation involving a plurality of such base transceiver stations of the network, to produce respective signal measures for all the base transceiver stations involved in the operation, each such signal measure serving to indicate the performance of a communications channel between the mobile station and the base transceiver station concerned, and also operable to employ the produced signal measures to determine which of the involved base transceiver stations should be used to transmit a subsequent downlink signal to the mobile station, and to cause the transmitter to include, in such an uplink signal transmitted thereby, a base transceiver station selection message identifying the determined base transceiver station(s). [0029] According to a ninth aspect of the present invention there is provided a base station controller, for use in a cellular mobile communications network to apply downlink signals to a plurality of base transceiver stations of the network, including: a receiver for receiving uplink signals from one or more of the base transceiver stations, at least one of which uplink signals includes, when a mobile station is engaged in a soft hand-off operation involving more than one of the base transceiver stations of the network, a base transceiver station selection message identifying which of the involved base transceiver stations should be used to transmit a subsequent one of the downlink signals to the mobile station; and a soft hand-off control unit operable to receive the uplink signal including the base transceiver station selection message and to transmit the subsequent downlink signal only to the determined base transceiver station(s) identified in the message. [0030] According to a tenth aspect of the present invention there is provided a soft hand-off control method for use in a cellular mobile communications network, wherein: when a soft hand-off operation involving more than one base transceiver station of the network is being performed, a mobile station produces respective signal measures for all the base transceiver stations involved in the operation, each such signal measure serving to indicate the performance of a communications channel between the mobile station and the base transceiver station concerned; and the produced signal measures are employed to determine which of the involved base transceiver stations should be used to transmit a subsequent downlink signal to the mobile station. [0031] The signal measures can be any suitable measure of the communications-channel performance between the mobile station and the base transceiver stations, for example signal strength measures (received signal strength in terms of power or amplitude or quality measures (frame error rate, signal-to-interference ratio, etc) or a combination of both strength and quality. BRIEF DESCRIPTION OF THE DRAWINGS [0032] Reference will now be made, by way of example, to the accompanying drawings, in which: [0033] [0033]FIG. 1, discussed hereinbefore, shows parts of a cellular mobile telecommunication network according to IS95; [0034] [0034]FIG. 2, also discussed hereinbefore, shows a schematic view for use in explaining processing of uplink signals in a soft hand-off operation performed by the FIG. 1 network; [0035] [0035]FIG. 3, also discussed hereinbefore, shows a schematic view for use in explaining processing of downlink signals in such a soft hand-off operation; [0036] [0036]FIG. 4, also discussed hereinbefore, illustrates the format of a time frame in the FIG. 1 network; [0037] [0037]FIG. 5 shows parts of a mobile telecommunication network embodying the present invention; [0038] [0038]FIG. 6 shows parts of a mobile station embodying to the present invention; [0039] [0039]FIG. 7 is a detailed block diagram showing parts of the FIG. 6 mobile station; [0040] [0040]FIG. 8 is a flowchart for use in explaining operation of the FIG. 6 mobile station; [0041] [0041]FIG. 9 is a schematic view for illustrating a possible format of a message transmitted by the FIG. 6 mobile station; [0042] [0042]FIG. 10 shows parts of a base transceiver station embodying the present invention; [0043] [0043]FIG. 11 shows parts of another base transceiver embodying the present invention; [0044] [0044]FIG. 12 is a detailed block diagram of parts of the FIG. 11 base transceiver station; [0045] [0045]FIG. 13 shows a flowchart for use in explaining operation of the FIG. 11 base transceiver station; [0046] [0046]FIG. 14 shows parts of a mobile station in another embodiment of the present invention; and [0047] [0047]FIG. 15 shows parts of a base station controller suitable for use with the FIG. 14 mobile station. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0048] [0048]FIG. 5 shows parts of a mobile telecommunication network embodying the present invention. In FIG. 5, elements that are the same as elements of the FIG. 1 network described previously have the same reference numerals and an explanation thereof is omitted. [0049] The FIG. 5 network is a wideband CDMA (W-CDMA) network for a proposed new standard for mobile telecommunications, referred to as a universal mobile telecommunications system (UMTS) or UMTS terrestrial radio access (UTRA). This is generally similar to the IS95-standard network described previously, although certain implementation details are yet to be finalized. Details that are different from IS95 include the frame duration, which is 10 ms, and the time-slot duration which is 625 μs. The overall bit rate is within the range from 8 kbits/s to 2 Mbits/s. Also downlink power control in W-CDMA is closed-loop and is based on the same principles as the uplink power control. [0050] In FIG. 5, each of three base transceiver stations (BTSs) 20 (BTS 1 , BTS 2 and BTS 3 ) is connected via a fixed network 5 to a base station controller (BSC) 30 , which is in turn connected to a mobile switching center (MSC) 7 . Each BTS 20 serves a cell 8 . A mobile station (MS) 40 is in a soft hand-off (SHO) region 9 and can receive downlink signals from, and transmit uplink signals to, all the BTSs 20 involved in the soft hand-off. [0051] The FIG. 5 network corresponds generally with the FIG. 1 network, but the MS 40 , BTSs 20 and BSC 30 are constructed and operate differently from the corresponding elements in FIG. 1. [0052] [0052]FIG. 6 is a block diagram showing parts of a MS 40 embodying the present invention. An antenna element 42 is connected (e.g. via a duplexer—not shown) to a receiver portion 44 and a transmitter portion 46 . A downlink signal processing portion 48 receives from the receiver portion 44 respective downlink signals DS 1 to DSn produced by n BTSs BTS 1 to BTSn (n is an integer) involved in the soft hand-off operation. The downlink signal processing portion 48 applies a BTS selection message BSM to the transmitter portion 46 . [0053] [0053]FIG. 7 shows a block diagram of the downlink signal processing portion 48 . The downlink signal processing portion 48 includes a downlink signal input portion 52 which receives the downlink signals DS 1 to DSn from the receiver portion 44 . The downlink signal processing portion 48 further includes respective TX and RX power storage portions 54 and 56 , each connected to the downlink signal input portion 52 . The TX power storage portion 54 receives a single power control bit PCB, or respective power control bits PCB 1 to PCBn corresponding respectively to the BTSs involved in the soft hand-off operation, and also receives from the downlink signal input portion 52 initial transmission powers TXP 1 to TXPn corresponding respectively to those BTSs. [0054] The downlink signal input portion 52 also applies to the RX power storage portion 56 received power measures RXP 1 to RXPn corresponding respectively to the BTSs, each representing the power at which a downlink signal from the corresponding BTS is received by the mobile station. [0055] Each of the power storage portions 54 and 56 includes storage regions corresponding respectively to the different BTSs. [0056] The downlink signal processing portion 48 also includes a required RX power calculation portion 58 which receives a further signal measure FER, representing a downlink frame error rate determined by the mobile station, from the downlink signal input portion 52 . [0057] The downlink signal processing portion 48 further includes a path loss calculation portion 60 which receives from the TX power storage portion 54 respective transmit powers TXP 1 to TXPn for the different BTSs and also receives respective receive powers RXP 1 to RXPn for the different BTSs from the RX power storage portion 56 . [0058] The downlink signal processing portion 48 further includes a required TX power calculation portion 62 which receives respective path loss measures PL 1 to PLn for the different BTSs from the path loss calculation portion 60 and a required RX power RRXP from the required RX power calculation portion 58 . [0059] The downlink signal processing portion 48 further includes a required TX power storage portion 64 and an interference calculation portion 66 , both of which receive from the required TX power calculation portion 62 first and second sets of required transmission powers. The first set of required transmission powers P BTS1 to P BTSn represent required transmission powers of the different BTSs when the mobile station 40 is not using maximum ratio combining (MRC). The second set of transmission power measures P′ BTS1 to P′ BTSn represent the required transmission powers of the different BTSs when MRC is employed at the MS 40 . The required TX power storage portion 64 has first and second sets of storage regions corresponding to the two sets of transmission power measures. [0060] The downlink signal processing portion 48 further includes an interference storage portion 68 which receives interference measures I BTS1 to I BTSn corresponding respectively to the different BTSs (transmitting alone), as well as a further interference measure I MRC representing interference when all BTSs are used to transmit downlink signals and MRC is performed at the MS 40 . The interference storage portion 68 has storage regions corresponding respectively to these different interference measures. [0061] The downlink signal processing portion 48 further includes an interference comparison portion 70 which receives the interference measures I BTS1 to I BTSn and I MRC from the interference storage portion 68 and produces a comparison signal COMP which is applied to a BTS selection portion 72 . The BTS selection portion 72 produces a BTS selection message (BSM) and a power control bit PCB (or plural PCBs PCB 1 to PCBn), which are applied to the transmitter portion 46 of the mobile station 40 . [0062] Operation of the mobile station 40 of FIG. 7 will now be explained with reference to the flowchart of FIG. 8. In this example, it will be assumed, for the sake of simplicity, that there are only two BTSs involved in the soft hand-off operation. [0063] In a first step S 1 the downlink signal input portion 52 detects, in a downlink signal received from a first one (hereinafter BTS 1 ) of the BTSs involved in the soft hand-off operation, for example a signal on a dedicated control channel DCCH thereof, the initial transmit power ITXP 1 of BTS 1 . [0064] As explained previously, the downlink power control method proposed for use in W-CDMA adjusts the transmission power of the BTSs in communication with a particular MS in dependence upon power control bits PCBs generated by the mobile station. At present, the proposed standard for W-CDMA specifies that a single PCB be used to control the downlink transmit powers of all of the BTSs involved in the soft hand-off operation. Thus, in this case all the involved BTSs increase or reduce their transmission powers together in accordance with the single PCB. However, it is also possible, in an embodiment of the present invention, to allocate each BTS involved in the soft hand-off operation its own individual PCB, enabling the MS to control the downlink transmission powers of the different involved BTSs independently of one another. In this case (as shown in parenthesis in FIG. 7) the TX power storage portion 54 receives PCBs PCB 1 to PCBn corresponding respectively to the different BTSs involved in the soft hand-off operation. [0065] In step S 1 the initial transmission power ITXP 1 for BTS 1 is stored in the storage region allocated to BTS 1 in the TX power storage portion 54 . Thereafter, each time a new PCB (PCB or PCB 1 , as the case may be) applicable to BTS 1 is generated by the MS (for example every time slot) the TX power storage portion 54 updates the transmission power TXP 1 stored in the storage region for BTS 1 so that, at any given time, the value stored represents the instantaneous downlink transmission power of BTS 1 . [0066] In step S 2 the initial transmission power ITXP 2 for the second BTS (hereinafter BTS 2 ) involved in the soft hand-off operation is detected by the downlink signal input portion 52 in one of the downlink signals received from BTS 2 and is stored in the storage region of the TX power storage portion 54 allocated to BTS 2 . The stored transmission power TXP 2 , for BTS 2 is also updated each time a PCB (PCB or PCB 2 ) applicable to BTS 2 is generated by the mobile station. [0067] Next, in step S 3 , the downlink signal input portion 52 processes the downlink signal DS 1 received from BTS 1 (either on a traffic channel TCH thereof or on a control channel dedicated control channel (DCCH) thereof) and derives therefrom a measure RXP 1 of the received power of the downlink signal DS 1 concerned. This measure (for example the received signal strength RSS) is stored in the storage region allocated to BTS 1 in the RX power storage portion 56 . [0068] In step S 4 the same operation is performed for BTS 2 and the result stored in the storage region allocated to BTS 2 in the RX power storage portion 56 . Incidentally, in steps S 3 and S 4 , the received power RXP may be calculated from the DCCH downlink signal in the event (as explained later) that the traffic channel TCH from the BTS concerned is switched off. [0069] In step S 5 the path loss calculation portion 60 receives from the storage location for BTS 1 in the TX power storage portion 54 the stored (and updated) transmission power TXP 1 for BTS 1 , and also receives from the storage region for BTS 1 in the RX power storage portion 56 the received power RXP 1 for BTS 1 . The path loss calculation portion 60 subtracts the received power RXP 1 from the transmit power TXP 1 to determine the path loss PL 1 for BTS 1 . In step S 6 the same operations are repeated for BTS 2 . [0070] In step S 7 the required RX power calculation portion 58 determines, based on a predetermined characteristic (e.g. the frame error rate FER) of the received downlink signals as a whole (e.g. after maximum ratio combining MRC), a required RX power RRXP which represents the minimum power that the mobile station presently needs to receive in order to produce an overall downlink signal DS of acceptable quality. [0071] In step S 8 the required TX power calculation portion 62 receives the path loss PL 1 for BTS 1 and the required RX power RRXP. Based on these inputs, it calculates a downlink transmission power P BTS1 required from BTS 1 assuming that BTS 1 is the only BTS permitted to send the downlink signal in the next time slot to the mobile station. This required transmission power P BTS1 may be calculated, for example, by adding together PL 1 and RRXP. The calculated required downlink transmission power P BTS1 is then stored in the TX power storage portion 64 in the storage region allocated to BTS 1 in the first set of storage regions thereof (the set relating to the case in which maximum ratio combining (MRC) is not performed in the mobile station). [0072] Then, in step S 9 , the interference calculation portion 66 receives the required downlink transmission power P BTS1 calculated in step S 8 and calculates therefrom a measure I BTS1 of the amount of network interference that would be caused by BTS 1 (alone) operating at the downlink transmission power P BTS1 . This measure is stored in an appropriate one of the storage region allocated to BTS 1 in the interference storage portion 68 . [0073] Next, in steps S 10 and steps S 11 the processings of steps S 8 and S 9 are repeated for BTS 2 . The resulting required downlink transmission power P BTS2 and the network-interference measure I BTS2 are stored respectively in storage regions allocated to BTS 2 in the portions 64 and 68 . [0074] In step S 12 the required TX power calculation portion 62 calculates, for each of the BTSs BTS 1 and BTS 2 , the required downlink transmission power P′ BTS1 or P′ BTS2 assuming that MRC is to be used at the mobile station. These results are stored in storage regions allocated to BTS 1 and BTS 2 in the second set of storage regions of the required TX power storage portion 64 . [0075] In step S 13 the interference calculation portion 66 employs the required downlink transmission powers P′ BTS1 and P′ BTS2 calculated in step, S 12 to determine a measure of the network interference that would result assuming that BTS 1 is transmitting at P′ BTS1 and BTS 2 is transmitting at P′ BTS2 . The resulting interference measure I MRC is stored in a further one of the storage regions of the interference storage portion 68 . [0076] Next, in step S 14 the interference comparison portion 70 compares the interference measures I BTS1 and I BTS2 retrieved from the interference storage portion 68 . If I BTS1 is less than I BTS2 processing proceeds to step S 15 in which I BTS1 is compared with I MRC . If I BTS1 <I MRC in step S 15 , in step S 16 the BTS selection portion 72 determines that the downlink signal in the next time slot should be sent to the mobile station by BTS 1 alone, on the basis that this will result in the lowest network interference. The BTS selection portion 72 generates a BTS selection message (BSM) specifying that BTS 2 is not to transmit the downlink signal in the next time slot. The BSM is delivered to the transmitter portion 46 of the mobile station for transmission to BTS 2 . At the same time, the BTS selection portion 72 determines the power control bit PCB to be transmitted to BTS 1 to control the downlink transmission power of BTS 1 in the next time slot so that it has the value P BTS1 calculated in step S 8 . As noted previously, this PCB may be a single PCB common to all BTSs involved in the soft hand-off operation, or a unique PCB (PCB 1 ) for BTS 1 . [0077] If, in step S 14 , I BTS2 was found to be less than or equal to I BTS1 , or if in step S 15 I MRC was found to be less than or equal to I BTS1 , processing proceeds to step S 17 . In step S 17 , the interference comparison portion 70 compares I BTS2 with I MRC . If I BTS2 is less than I MRC processing proceeds to step S 18 in which the BTS selection portion 72 determines that the downlink signal for the mobile station in the next time slot should be transmitted by BTS 2 alone, on the basis that BTS 2 operating alone will produce the lowest network interference. In this case, the BTS selection portion 72 generates a BSM which instructs BTS 1 not to transmit in the next time slot. Also, the PCB applicable to BTS 2 is set by the BTS selection portion 72 to control the downlink transmission power of BTS 2 to meet the required TX power P BTS2 calculated in step S 10 . [0078] If in step S 17 the result of the comparison is that I MRC is less than or equal to I BTS2 , processing proceeds to step S 19 in which the BTS selection portion 72 determines that both BTS 1 and BTS 2 should be used to transmit the downlink signal in the next time slot, on the basis that this will result in the lowest network interference. In this case, the BTS selection portion 72 generates a BSM specifying that both BTSs are to transmit in the next time slot, and sets the PCB (or PCBs) to cause the BTSs to transmit the downlink signal in the next time slot at the required transmission powers P′ BTS1 and P′ BTS2 calculated in step S 12 . [0079] Thus, in the example described above it can be seen that three different candidate BTS selections are identified: a first candidate selection in which BTS 1 alone is specified for transmitting the downlink signal; a second candidate selection in which BTS 2 alone is specified for transmitting the downlink signal; and a third candidate selection in which both BTS 1 and BTS 2 are specified for transmitting the downlink signal. For each candidate selection, the required transmission power P BTS (or P′ BTS ) of each BTS specified in the selection is calculated and a measure of the network interference that would result from the specified BTS(s) transmitting is also calculated. These network-interference measures are then employed (e.g. the lowest measure is found by comparison of the measures) to decide which of the candidate selections to use for transmission of the downlink signal, so as to tend to reduce the network interference associated with that transmission. [0080] It is not essential for the candidate selections to include selections specifying only one BTS. For example, if there are three BtSs involved in a soft hand-off operation, the selections could be BTS 1 +BTS 2 , BTS 2 +BTS 3 , BTS 3 +BTS 1 , and BTS 1 +BTS 2 +BTS 3 . It is also not essential for the candidate selections to include a selection specifying all the BTSs involved in the soft hand-off. Furthermore, the transmission powers for the BTSs specified in a particular selection can be set to any suitable combination of values capable of facilitating adequate reception of the downlink signal at the subject mobile station. Thus, for example, two or more candidate selections could specify the same BTSs but specify different respective sets of transmission powers for the selections. [0081] One example of the possible format of the BTS selection message BSM will now be explained with reference to FIG. 9. [0082] The BTSs involved in a soft hand-off operation are ranked in some way. For example, the ranking may be carried out in the mobile station based on a predetermined property of the respective downlink signals DS 1 to DSn that are received by the MS 40 , for example the received signal strength (RSS). Alternatively, the ranking may be on a “first-come first-served” basis, i.e. on the order in which the BTSs became involved in the soft hand-off operation. Alternatively, the ranking could be random. Once the ranking has been determined, the mobile station sends a ranking message RM, indicating the order in which the BTSs are presently ranked, via a control channel to all BTSs. [0083] As shown in FIG. 9, the BSM has one bit corresponding to each rank of BTS, and these bits are arranged in the BSM in the ranking order determined by the MS. Take, for example, the case described previously with reference to FIG. 8 in which there are only two BTSs involved in the soft hand-off operation, namely BTS 1 and BTS 2 . Assume also that, in the order of ranking determined by the mobile station, BTS 2 is the highest-ranked BTS (rank {circle over ( 1 )}), and that the other BTS, BTS 1 , has rank {circle over ( 2 )}. Assume also that the outcome of the comparisons of the interference measures is the outcome shown in S 16 , namely that BTS 2 should not transmit the downlink signal in the next time slot. To communicate this result to the BTSs involved in the soft hand-off operation, the first bit (corresponding to rank {circle over ( 1 )}) in the BSM is set to 0, to indicate that BTS 2 should not transmit the downlink signal in the next time slot. The second bit of the BSM (which corresponds to the rank-{circle over ( 2 )} BTS) is set to 1, to indicate that the rank-{circle over ( 2 )} BTS, BTS 1 , should transmit the downlink signal in the next time slot. Any remaining bits of the BSM can be set to a “don't-care” state, since in this example only two BTSs are involved in the soft hand-off operation. Incidentally, the BSM in this case could consist of two bits only, of course. [0084] The ranking of a BTS may periodically require updating, for several reasons. Firstly, as the MS 40 moves, a downlink signal may be received from a new BTS or an existing BTS may no longer may able to provide a detectable downlink signal. Secondly, the qualities of the signals received from the BTSs 20 may have changed, e.g. due to fading. Thus, from time to time a ranking update is required. Such an update may be carried out periodically at regular time intervals (for example every several hundred milliseconds as in GSM networks), or every frame or even every time slot. Alternatively, the ranking could be updated only when a new BTS is detected or contact with an existing one lost. [0085] [0085]FIG. 10 is a block diagram showing parts of a BTS 20 embodying the present invention. This BTS 20 is specially adapted to receive and process the ranking message RM and the BTS selection message BSM sent by the MS 40 of FIG. 6. [0086] An antenna element 22 is connected (e.g. via a duplexer—not shown) to a receiver portion 24 and a transmitter portion 26 . A soft hand-off control portion 28 receives an uplink signal US from the receiver portion 24 , and in turn applies the received US (or a signal derived therefrom) to the fixed network 5 for transmission to the BSC 30 . The transmitter portion 26 receives a downlink signal DS via the connection line 5 from the BSC 30 (FIG. 5) and a disabling signal DIS from the soft hand-off control portion 28 . [0087] In use of the BTS 20 , the uplink signals sent by the MS 40 when it is in the soft hand-off region 9 include, from time to time, a ranking message RM. The uplink signals US detected by the receiver portion 24 in the BTS 20 are applied to the soft hand-off control portion 28 . When the soft hand-off control portion 28 detects that a ranking message RM is included in one of the uplink signals US received thereby, it processes the ranking message concerned to determine the rank of its BTS within the ranking order determined by the MS. [0088] In each time slot, the uplink signals US produced by the receiver portion 24 also include a BTS selection message BSM determined by the MS 40 as described above. [0089] Operation of the soft hand-off control portion 28 in response to the presence of such a BSM in the uplink signal US produced by the receiver portion 24 will now be described. [0090] It is assumed that, by the time the BSM is received, a ranking message RM has already been received and processed (as indicated above) by the soft hand-off control portion 28 . [0091] The BSM is supplied by the receiver portion 24 to the soft hand-off control portion 28 where is examined. The soft hand-off control portion 28 checks the rank of its BTS based on the last-received ranking message and then examines the bit corresponding to that rank in the BSM. If the bit is 0 the soft hand-off control portion 28 applies a disabling signal DIS to the transmitter portion 26 to prevent it from transmitting the downlink signal in the next time slot. [0092] The measure of network interference I BTS1 , I BTS2 or I MRC can be calculated as follows by considering the interference that would be experienced by an imaginary mobile station, other than the subject mobile station, operating in the soft hand-off region (FIG. 5), as a consequence of the BTS(S) concerned transmitting at the determined required transmission power(s). In the case of I BTS1 , for example, the interference is calculated based on the required transmission power P BTS1 from BTS 1 to the subject mobile station and the associated mean path loss experienced by the imaginary mobile station (which is the same as for the subject mobile station). This mean path loss is a time-averaged path loss for which the averaging period is chosen so as to average out (or ideally eliminate) the effects of Rayleigh fading. In other words, the path loss variation due to Rayleigh fading is averaged out. [0093] In the case of I MRC the interference is calculated based on the cumulative sum of the respective carrier power levels of BTS 1 and BTS 2 at the antenna of the imaginary mobile station. Again, these carrier power levels are calculated based on the required transmission powers P′ BTS1 and P′ BTS2 for BTS 1 and BTS 2 when MRC is used and the respective mean path losses which have already been established at the subject mobile station (and are assumed to be the same for the imaginary mobile station). [0094] Take, for example, a situation in which the downlink signal from BTS 2 is undergoing a deep fade. This means that PL 2 will be large relative to PL 1 . In this case, the required transmission power PBTS 2 for BTS 2 will be large as compared to the required transmission power BTS 1 for BTS 1 . Thus, I BTS2 will be large relative to I BTS1 . Also, in view of the large PL 2 , P′ BTS2 will also be large so that I MRC will be larger than I BTS1 . Accordingly, the decision is made that BTS 2 should not transmit the downlink signal in the next time slot, so as to reduce the network interference resulting from transmission of that downlink signal. [0095] In the embodiment described above, the selection of the BTS to be used to transmit the downlink signal in the next time slot is made in the mobile station 40 . However, it is not essential that this decision be made there. In another embodiment, which will be described hereinafter with reference to FIGS. 11 to 13 , each BTS includes a modified soft hand-off control portion, and these modified hand-off control portions cooperate to carry out the downlink-signal decision making. [0096] Referring firstly to FIG. 11, a BTS 120 is constituted in basically the same manner as the BTS 20 described previously with reference to FIG. 9 but has a modified soft hand-off control portion 128 in place of the soft hand-off control portion 28 in the FIG. 9 BTS. [0097] An example of the constitution of the modified soft hand-off control portion 128 is shown in FIG. 12. [0098] As will apparent from FIG. 12 itself, the modified soft hand-off control portion 128 in this embodiment includes the portions 54 , 56 , 58 , 60 , 62 , 64 , 66 , 68 and 70 previously included in the downlink signal processing portion 48 of the MS 40 in the FIG. 7 embodiment. However, in place of the downlink signal processing portion 52 in the FIG. 7 embodiment, the FIG. 12 embodiment has an uplink signal input portion 152 . Also, in place of the BTS selection portion 72 in the FIG. 7 embodiment, the FIG. 12 embodiment has a decision portion 172 . [0099] Operation of the FIG. 12 embodiment will now be described with reference to the flowchart of FIG. 13. Again, in the FIG. 13 flowchart it is assumed, for the sake of simplicity, that only two BTSs, BTS 1 and BTS 2 , are involved in the soft hand-off operation. As will be apparent from FIG. 13 itself, many of the steps in the FIG. 13 flowchart are the same as (or correspond to) the steps S 1 to S 19 in the FIG. 8 flowchart relating to operation of the FIG. 7 embodiment. [0100] The FIG. 13 flowchart relates to processing performed at BTS 1 during the soft hand-off operation. Accordingly, the step S 1 used in the FIG. 8 flowchart is not required in FIG. 13, as the soft hand-off control portion 128 in BTS 1 already knows the instantaneous downlink transmission power of BTS 1 (this is stored in the storage region allocated to BTS 1 in the TX power storage portion 54 ). However, BTS 1 does need to know the downlink transmission power of the other BTS, BTS 2 , involved in the soft hand-off operation. Accordingly, in step S 2 , the initial transmission power ITXP 2 for BTS 2 is received (in one of the uplink signals US) from the mobile station. The mobile station can include this information for example in the ranking message RM which it transmits periodically or whenever a new BTS becomes involved in the soft hand-off operation. The received initial transmission power ITXP 2 for BTS 2 is stored in the storage region allocated to BTS 2 in the TX power storage portion 54 . [0101] Incidentally, the downlink power control in this embodiment is performed in the same way as in the FIG. 7 embodiment. Thus, the mobile station may either use a single PCB in common to control the downlink transmission powers of all of the BTSs involved in the soft hand-off operation, or alternatively the mobile station may allocate each involved BTS its own PCB. In any event, the TX power storage portion 54 needs to receive the PCBs applicable to all of the BTSs involved in the soft hand-off operation. If there is a single PCB allocated to all the BTSs, then this single PCB will be available to the soft hand-off control portion 128 from one of the uplink signals US received from the mobile station. If, on the other hand, each involved BTS is allocated its own PCB by the mobile station, then some mechanism must be provided for enabling each involved BTS to receive the respective PCBs of all the other involved BTSs. One suitable mechanism for achievings this is described in co-pending PCT patent publication No. WO 99/59367, the entire content of which is incorporated herein by reference. In this proposed mechanism, the mobile station includes, in an uplink signal transmitted thereby to each involved BTS, a power control message (PCM) made up, in the order of ranking of the involved BTSs determined by the mobile station, the respective PCBs of all the involved BTSs. Thus, this PCM would have a format similar to that of the BSM shown in FIG. 9, except that in this case each bit would be the PCB of the BTS concerned. [0102] Thus, in the FIG. 12 embodiment, any PCB (or PCM as the case may be) included in an uplink signal US received from the mobile station is detected by the uplink signal input portion 152 and supplied to the TX power storage portion 54 so as to enable the TX power storage portion 54 to update the transmission power TXP for each of the BTSs involved in the soft hand-off operation. [0103] After the step S 2 , processing proceeds to a step S 3 ′. This step S 3 ′ corresponds generally to the step S 3 in the FIG. 8 flowchart. In this step S 3 ′, the uplink signal input portion 152 detects, in one of the uplink signals US received from the mobile station, a transmission power control (TPC) signal representing the power RXP 1 at which the downlink signal from BTS 1 was received by the mobile station. This received power RXP 1 for BTS 1 is stored in the storage region allocated to BTS 1 in the RX power storage portion 56 . In step S 4 ′ the same operation is repeated for BTS 2 . [0104] Then, in steps S 5 and S 6 , the path loss calculation portion 60 calculates the respective path losses PL 1 and PL 2 for the downlink signals sent to the mobile station by BTS 1 and BTS 2 . [0105] In step S 7 ′, which corresponds to the step S 7 in the FIG. 8 flowchart, the required RX power calculation portion 58 determines a required receive power RRXP for the mobile station. This may be achieved, for example, by the mobile station including, in one of the uplink signals US transmitted thereby, a measure of the downlink channel performance, for example the frame error rate (FER) of the downlink signal received by the mobile station. When such a communications-channel measure (FER) in a received uplink signal US is detected by the uplink signal input portion 152 it supplies this measure to the required RX power calculation portion 58 for use thereby in generating the RRXP. [0106] The steps S 8 to S 15 and S 17 in FIG. 13 are then the same as the corresponding steps in the FIG. 8 flowchart. [0107] In step S 16 ′, which corresponds to the step S 16 in the FIG. 8 flowchart, the decision portion 172 in the soft hand-off control portion 128 of BTS 1 determines that BTS 1 (alone) should transmit the downlink signal DS in the next time slot to the mobile station on the basis that this will result in the lowest network interference. The decision portion 172 then generates suitable power control information (for example a PCB) so as to adjust the downlink transmission power to the value P BTS1 determined in step S 8 . [0108] Rather than a PCB, this power control information may simply be the explicit required transmission power P BTS1 in this case. [0109] If the determination in step S 17 is that I BTS2 is less than I MRC , the decision portion 172 determines in step S 18 ′ that BTS 1 should not transmit the downlink signal in the next time slot. Thus, the decision portion 172 applies the disabling signal DIS to the transmission portion 26 in its BTS (BTS 1 ). [0110] If, on the other hand, in step S 17 it is determined that I MRC is less than or equal to I BTS2 , then in step S 19 ′ the decision portion 172 determines that both BTS 1 and BTS 2 should be used in the next time slot to transmit the downlink signal. In this case, it sends appropriate power control information (a PCB or possibly the explicit downlink transmission power P′ BTS1 ) to the transmission portion 26 . [0111] It will be appreciated that the processing shown in FIG. 13 is also carried out independently in the other BTS, BTS 2 , involved in the soft hand-off operation (in that case, of course, in step S 2 , the received initial transmission power that is received and stored is ITXP 1 relating to BTS 1 ). [0112] Naturally, the decision-making embodied in steps S 14 to S 19 ′ in FIG. 13 must be made consistent in each different BTS involved in the soft hand-off operation so that there will always be at least one BTS which transmits the downlink signal to the mobile station in the next time slot. [0113] In the embodiments described above, the TX power storage portion 54 receives the initial downlink transmission powers of the involved BTSs and then updates these as necessary on receipt of the power control bits PCBs for the different BTSs. However, it would also be possible for the instantaneous downlink transmission powers TXP themselves to be supplied directly to the TX power storage portion 54 in each time slot in place of the PCBs. [0114] It will also be appreciated that it would also be possible for the decision as to which BTS is to transmit the downlink signal in the time slot to be made in the BSC 30 instead of in each involved BTS. In this case, the elements 54 to 70 , 152 and 172 shown in FIG. 11 would be provided in the BSC instead of in each BTS. [0115] It will also be understood that the way in which the transmission powers TXP (or IXTP+ΣPCB) and receive powers RXP are made available to the decision-making entity (be it MS, BTS or BSC) is not critical to the invention. For example, it is not necessary for the MS to rank the BTSs. All that is necessary is that each BTS is able to identify to which BTS a particular received value (e.g. ITXP or RXP) relates. Such identification could be carried out in many different ways other than ranking. [0116] It will also be understood that it is not necessary for the processing shown in FIGS. 8 and 13 to take place every time slot. It would be possible for the signals such as RXP and PCM to be transmitted only once per frame, in which case the decision-making would be made on a frame-by-frame basis. [0117] Next, another example of downlink processing in the FIG. 5 network will be described with reference to FIGS. 14 and 15. In such downlink processing, if macro-diversity based on maximum ratio combining (MRC) is required at the MS during the soft hand-off operation, all of the BTSs involved in the soft hand-off operation must transmit the same information to the MS. However, if MRC is not required at the MS in the soft hand-off region, downlink macro-diversity can be based on selection (or switched) diversity at the BSC 30 , in accordance with another embodiment of the present invention. [0118] [0118]FIG. 14 is a block diagram showing parts of a MS 40 in this embodiment of the present invention. An antenna element 42 is connected (e.g via a duplexer—not shown) to a receiver portion 44 and a transmitter portion 46 . A signal selection information processing portion 48 from the receiver portion 44 respective downlink signals DS 1 to DS 3 produced by the three BTSs BTS 1 to BTS 3 involved in the soft hand-off operation. The signal selection information processing portion 48 applies a ranking message RM and a power control message PCM to the transmitter portion 46 . [0119] The signal selection information processing portion 48 processes the respective downlink signals DS 1 to DS 3 received from the BTSs (BTS 1 to BTS 3 ) involved in the soft hand-off operation, and compares these downlink signals according to a predetermined property. In a preferred embodiment, the predetermined property is the received signal strength (RSS), possibly together with the signal-to-interference ratio (SIR). These performance measures are determined for the downlink DCCH. [0120] The signal selection information processing portion 48 employs the performance measures to select which of the BTSs involved in the soft hand-off operation is to be used to transmit the downlink signal to the MS in the next time slot. [0121] The signal selection information processing portion 48 may select the BTS that is to transmit the downlink signal in the next time slot based on the following cases. [0122] Case 1: If the RSS (and/or SIR) of a single BTS is higher than each other BTS, that single BTS is selected to transmit the downlink signal in the next time slot. [0123] Case 2: If two or more BTSs have comparably-good RSS (and/or SIR), one of them is selected based on an order of ranking (e.g. order of involvement in the soft hand-off operation or random). [0124] Case 3: If all the BTSs involved in the soft hand-off operation fail to meet a prescribed RSS (and/or SIR) threshold, all the BTSs are selected to transmit the downlink signal in the next time slot, so that a MRC operation can be performed at the MS 40 to give the best chance of obtaining a useful signal. [0125] After determining which BTS(s) is/are to be used, the signal selection information processing portion 48 transmits a BTS selection message (BSM), identifying the BTS(s) to be used, to all of the BTSs on a control channel. [0126] For example, using two bits to provide the BSM, the BSM may be set to “01” to designate BTS 1 ; “10” to designate BTS 2 ; and “11” to designate BTS 3 . “00” denotes that all the BtSs should be used to transmit the downlink signal in the next time slot. [0127] Each BTS receives the BSM via the control channel from the MS 40 . One or more of the BTSs then forward the BSM to the BSC 30 . All BTSs could forward the BSM to the BSC. [0128] [0128]FIG. 15 shows part of a BSC adapted to perform downlink processing with the FIG. 14 mobile station. The BSC 30 includes a control portion 32 and a selector portion 34 . [0129] In this example, it is assumed that the connection lines 5 1 to 5 3 linking each BTS to the BSC 30 are duplex lines which carry respective uplink and downlink signals US and DS between the BTS concerned and the BSC. For example, a first connection line 5 1 carries respective uplink and downlink signals US 1 and DS 1 between the BTS 1 and the BSC 30 . [0130] The selector portion 34 receives at its input a downlink signal DS supplied by the MSC ( 7 in FIG. 5). The selector portion 34 has three outputs connected respectively to the connection lines 5 1 to 5 3 . [0131] The selector portion 34 also has a control input which receives a selection signal SEL. In response to the SEL selection signal the selector portion 34 connects its input to one, or all, of its three outputs. [0132] The control portion 32 also has three inputs connected respectively to the connection lines 5 1 to 5 3 for receiving the uplink signals US 1 to US 3 from BTS 1 to BTS 3 respectively. The control portion applies the selection signal SEL to the selector portion 34 . As can be appreciated the selector portion 34 may be part of the BTSs, such that the selection signal SEL selects a BTS(s) for transmission of the downlink signal. [0133] In operation of the BSC shown in FIG. 15, in each time slot of the uplink signal the control portion 32 receives one or more of the three uplink signals US 1 to US 3 from the BTSs involved in the soft hand-off operation. When the BSM supplied by the MS 40 is detected within a received uplink signal US 1 , US 2 or US 3 , the control portion 32 examines the BSM and determines therefrom which of the BTSs is to be used to transmit the downlink signal in the next time slot to the MS 40 . [0134] If the BSM designates a single BTS, the control portion 32 sets the selection signal SEL such that the selector portion 34 supplies the downlink signal DS just to that one of the connection lines 5 1 to 5 3 connecting the BSC 30 to the designated BTS. If, on the other hand, all BTSs are designated by the BSM, the selection signal SEL is set so that the downlink signal DS received from the MSC 7 is supplied to all of the connection lines 5 1 to 5 3 . [0135] It will be appreciated that it is not necessary for the downlink processing to be performed on a time slot-by-time slot basis. It could be performed on a frame-by-frame basis or the BTS selection could be made at some other suitable time interval. [0136] It would also be possible for the signal selection information processing portion 48 (FIG. 14) to include its own storage portion enabling it to store a past history of the RSS (and/or SIR) measures for the different BTSs currently involved in the soft hand-off operation. In this case, it would be possible for the MS to employ more sophisticated decision-making in relation to the BTS selection so as to avoid undesirable effects caused by temporary reception phenomena or other problems caused by too frequent-changing of the BTS selection. [0137] It is not necessary for the mobile station to carry out the comparison of the signal measures for the different downlink signals and make the determination of the BTS to be used to transmit the downlink signal. The comparison and BTS determination could be carried out in the BSC; in this case instead of transmitting the BSM to the BTSs involved in the soft hand-off operation, the mobile station could transmit the downlink signal measures themselves (in some suitable form). These measures would then be delivered in the usual way to the BSC, enabling it to compare them and then make the BTS determination. [0138] In the embodiment of FIGS. 6 to 8 the processing is carried out mainly in the mobile station, whereas in the embodiment of FIGS. 11 to 13 the processing is carried out mainly in the BTSs. However, the present invention is not limited to these possibilities. For example, the processing could be carried out mainly in the base station controller or in the mobile switching center. It would also be possible for the processing to be distributed amongst any two or more or these network elements. [0139] Furthermore, it would be possible for the decisions to be made at time intervals other than frames or time slots, for example based on a time interval consistent with the fading characteristics of the RF channels in the network. [0140] Although the present invention has been described above in relation to the proposed European wideband CDMA system (UTRA) it will be appreciated that it can also be applied to a system otherwise in accordance with the IS95 standard. It would also be possible to apply the invention in other cellular networks not using CDMA, for example networks using one or more of the following: multiple-access techniques: time-division multiple access (TDMA), wavelength-division multiple access (WDMA),frequency-division multiple access (FDMA) and space-division multiple access (SDMA).

In a cellular mobile communications network a mobile station is capable of receiving a downlink signal from each of a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel. A transmission property of the downlink signals from the plurality of base stations to the mobile station is measured, and decided, in dependence upon the measure of the transmission property, a preferred base station transmitting the downlink signal with a preferred transmission property among the plurality of the base stations. The mobile station includes, in the uplink signal, data indicating the preferred base station(s) for transmitting the subsequent downlink signal to the mobile station. The base stations receiving the uplink signal identify from the data the preferred based station(s) and only the base station(s) identified as the preferred base station(s) transmits a subsequent downlink signal to the mobile station. Interference in such a cellular mobile telecommunications network can therefore be reduced.

BACKGROUND OF THE INVENTION This invention relates generally to a method of cold on-column injection of a liquid sample onto a capillary gas chromatography column and more particularly to such a method that can be used with a relatively larger sample size without producing the peak distortion or splitting observed under conventional on-column injection conditions. The two principal objectives of a sampling technique in capillary gas chromatography are to allow identical composition for sample injected onto the column and sample prior to the injection, and to introduce no or minimum extra column band broadening effects so that the total column resolving power is maintained. The former objective is easily achieved by the on-column injection technique because non-vaporizing ("cold") on-column injection, unlike conventional vaporizing injection techniques (split, splitless or direct), can deliver a sample into a capillary gas chromatography column with little effect on composition. The discriminative, adsorptive and thermal effects commonly observed with vaporizing injectors are largely absent, and excellent quantitative accuracy and precision are obtainable. Thus, on-column injection has been successfully applied to a number of difficult sampling problems. As to the latter of the aforementioned objectives, however, intolerable band boardening has been produced by the injection of a liquid sample into a capillary column due to the dynamic spreading of the liquid sample by the carrier gas over a significant length of the column inlet. As described by K. Grob, Jr. in J. Chromatogr., Vol. 213 (1981) at page 3, an on-column injection of a large sample size can result in chromatographic peak splitting due to the effect of the column being flooded by the liquid sample. This liquid sample flooding not only reduces the total available column resolving power and lifetime but also provides minimal use for qualitative and quantitative chromatographic information. The extent of this flooding along the length of the column depends upon the sample size, the column diameter, the carrier gas flow rate, the solvent physicochemical properties, and the column temperature (which affects the viscosity of the carrier gas and surface tension of the liquid sample). In general, a sample size in the range of 1-2 microliters can typically flood a column length of more than 50 cm. A larger sample size up to 10 microliters can easily flood several meters of the column inlet. Thus, this initial spreading of the liquid sample zone is one of the most serious constraints on the use of the method, resulting not only in a non-reproducible peak profile depending on the distribution of the solute molecules within the flooded sample zone but also an extensive peak broadening which is determined by the initial sample bandwidth. One of the attempts to reduce the effect of liquid sample flooding described by K. Grob, Jr. et al in J. Chromatogr., Vol. 244 (1982) at page 185 has been by removing the stationary phase on the first few meters of the column to prevent retention trapping of the non-uniformly distributed solute molecules. After injection, the flooded column inlet zone is heated up to vaporize sample molecules to be carried downstream to the column zone where stationary liquid traps solute molecules in a narrow initial sample zone. The technique improves the peak shape over that obtained with a conventional on-column injector. This technique, however, has limited success in practical applications due to the following drawbacks. Firstly, it is difficult in practice to strip stationary phase from a column inlet. In particular, nonpolar phases and chemically bonded phases are not completely removable. The use of an uncoated precolumn may allow satisfactory surface characteristics for the requirement of utilizing the retention gap technique, but the practical difficulties and constraints in column connection techniques have to be taken into consideration. Secondly, the retention gap technique does not solve the fundamental problem of sample size limitation. The amount of sample injected is again limited by the length of the retention gap. A sample size of 3 microliters may require 2-3 meters of retention gap to allow satisfactory peak shape. Thirdly, uncoated bare column walls for the retention gap may produce undesirable adsorption effects. Deactivation of the precolumn may not give satisfactory results due to the possibility of retention of solute molecules on the deactivated phase or phases, defeating the retention gap effect. Fourthly, the technique requires that the column oven temperature be cooled down to below the solvent boiling point before every injection. This could require more time than that required for a chromatographic separation. The speed of analysis is thus constrained by the injection technique. It is therefore an object of this invention to provide a solute focusing method of introducing a liquid sample into a gas chromatographic column. It is another object of this invention to provide an on-column injection method in gas chromatography which can yield chromatograms of good quality with relatively large sample sizes without causing intolerable peak shape distortion and, hence, useless chromatographic information. SUMMARY OF THE INVENTION The above and other objectives are achieved by applying solute focusing techniques to the on-column injection. The injection zone, or the inlet end of the chromatographic column, is kept at a temperature below the boiling point of the solvent while the adjacent downstream zone is kept at a higher temperature so that the following characteristics for an ideal on-column injection process can be achieved: (1) to allow liquid sample injection; (2) to vaporize and separate solvent from solute molecules quickly after injection; (3) to apply solute focusing technique to minimize initial solute molecular zone spreading; and (4) to allow separately temperature programmed injection and vaporization zones to obtain optimum resolution and speed of analysis. BRIEF DESCRIPTION OF DRAWINGS FIGS. 1(a) and 1(b) show schematically the principle of solute focusing technique which is applied to on-column injection according to the present invention. FIG. 2 is a portion of the experimental results according to the method of the present invention, showing the effects of increasing sample size on peak shape. FIG. 3 is a result of comparison experiment without solute focusing, showing the effects of increasing sample size on peak shape. DETAILED DESCRIPTION OF THE INVENTION The solute focusing technique of the present invention can be practiced, for example, by using the on-column gas chromatographic injector disclosed by P. L. Feinstein in U.S. patent application Ser. No. 342,958, filed Jan. 26, 1982 and assigned to the present assignee. The principle of the method is shown schematically in FIGS. 1(a) and (b). For the sake of simplicity, FIG. 1 illustrates a situation where the liquid sample introduced into a column 11 from a needle 12 consists of only one kind each of solute and solvent molecules (illustrated by shaded and open circles, respectively). An inlet portion 15, to be identified as injection zone, of the column 11 is surrounded by a temperature controlling means 25 including, for example, an electric heater and a cryogenic cooler for regulating the temperature of the injection zone 15. The zone inside the column 11 adjacent to and downstream from the injection zone 15 is identified as the vaporization zone 16 and is surrounded by a second temperature controlling means (column oven) 26 which controls the temperature of the vaporization zone 16. Thus, it is possible to control the injector and oven temperatures independently of each other and to select a variety of different combinations of these temperatures. In operation, the sample is injected as shown in FIG. 1(a) in its liquid state. For solute focusing, the injection zone 15 is held at a temperature 20° to 40° C. below the solvent boiling point during injection, while the vaporization zone 16 is heated at 10° to 20° C. above the solvent boiling point. During injection, the relatively cold injection zone 15 becomes flooded to some degree with liquid sample. As the liquid is moved downstream by carrier flow and enters the hot vaporization zone 16, the solvent evaporates rapidly, and is carried away by the mobile phase, leaving the solutes trapped in a narrow stationary liquid band at the front of the vaporization zone 16 (FIG. 1(b)). Molecules which may flow back from the vaporization zone 16 will recondense in the injection zone 15 maintained at a low injection zone temperature in the meantime. Immediately after the introduction of liquid sample is completed, the injection zone temperature is quickly increased to a level significantly higher than the solvent boiling point. This has the effect of driving any residual sample into the vaporization zone 16 where solute molecules are trapped, focused to a very narrow injection sample bandwidth. After the injection zone 15 reaches this final temperature, normal oven temperature programming is started so that on-column injection can be carried out under the correct non-vaporizing conditions, while flooding of a large column section is avoided. Stripping of the inlet section is not required since band sharpening is achieved by a combination of thermal focusing and retentive focusing (cold trapping). Vapor backflow during injection into the cooled injection zone 15 is not a concern since the entire area is heated after injection. Experimentally observed effects of increasing sample size on the chromatograph peak shape are shown in Table I below both with and without solute focusing. In these experiments, the sample was an n-alkane mixture in isooctane (boiling at 98° C.). With solute focusing the injection zone temperature was raised from 20° C. to 300° C. at the rate of 180° C./min while the vaporization zone temperature was initially kept at 110° C. for one minute and then raised to 300° C. at the rate of 10° C./min. Without solute focusing, the injection and vaporization zone temperatures were the same and were held for one minute initially at 80° C. and then raised to 300° C. at the rate of 10° C./min. FIG. 2 shows chromatograms obtained with solute focusing under these conditions. In contrast to the results without solute focusing, (FIG. 3), these chromatograms for sample sizes of 1 to 8 microliters show excellent peak shape and nearly constant peak widths from 1- up to 8-microliter injection sizes. Table I lists the experimentally determined peak widths at half height for several peaks from the chromatograms obtained both with and without solute focusing. TABLE I______________________________________InjectedAmount With Solute Without(Microliter) Solute Focusing Solute Focusing______________________________________1.0 n-C26 3.1 3.5 n-C30 3.0 5.5 n-C44 2.6 5.45.0 n-C26 3.2 14.4 n-C30 3.0 17.1 n-C44 3.8 18.28.0 n-C26 3.2 21.7 n-C30 3.1 22.9 n-C44 4.0 26.7______________________________________ The present invention has been described above only in terms of the general method and one set of experiments. The above description, however, is to be considered as illustrative rather than as limiting, and this invention is accordingly to be broadly construed. For example, FIG. 1 is to be interpreted merely as a schematic illustration so that the depicted dimensional relationships are not intended to be realistic. The length of the injection zone, however, is normally between 10 and 15 cm which can have stationary phase either present or stripped. The injection and vaporization zone temperatures can also be adjusted conveniently although the vaporization zone temperature should usually be more than 10° C. higher than the solvent boiling point at 1 bar. This initial vaporization zone temperature in a constant flow pneumatics system may be determined by and optimized for the chromatographic resolution and speed of analysis. It can be above solvent boiling point by more than 10° to 15° C. to allow faster analysis time if the solute components of interest can be satisfactorily separated. In a constant pressure pneumatics, however, the applicable initial vaporization zone temperature is limited to about 10° to 15° C. above the solvent boiling point. This is due to the fact that a high vaporization zone temperature could produce rapid vaporization and pressure increase inside the column which could force liquid sample backflow into the injector and result in sample loss and peak shape distortion. A constant pressure pneumatics has also a limited applicable sample size due to the combined gas pressure of the carrier gas, and the vaporized sample inside the column may exceed the pressure at the injection zone during injection process. The proposed solute focusing technique performs best in a constant flow pneumatics system with a gas leak-tight on-column injector. A slow on-column injection of large sample size in a constant flow pneumatics systems prevents backflow of the vaporized sample inside the column because of a constant flow of carrier gas into the column maintained by the constant flow controller. The scope of the invention is defined only by the following claims.

A solute focusing method is applied to the on-column injection of a liquid sample in gas chromatography so that relatively large sample sizes can be used without causing intolerable column flooding. The injection zone of the column is kept originally at a temperature below the solvent boiling point but the temperature in the adjacent downstream zone is kept higher than the solvent boiling point so that the solvent will evaporate and flow downstream, leaving the solute molecules concentrated within a relatively limited length along the column.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. Provisional Patent Application No. 61/867,273 filed Aug. 19, 2013, which is incorporated herein to the extent not inconsistent herewith. BACKGROUND [0002] The brown recluse spider, Loxosceles recluse (Araneae: Sicariidae), is a common household pest in the Midwestern United States. It is mainly nocturnal and is capable of inflicting a venomous bite. Its coloration ranges from light to dark brown with markings on the dorsal side of the cephalothorax. L. recluse spiders have six eyes arranged in three pairs. They average about three-eighths of an inch in size. [0003] Spider traps are known to the art, for example as described in U.S. Pat. Nos. 4,048,747, 4,052,811, 4,244,134, 4,324,062, 4,608,774, 4,819,371, 5,513,465, 5,572,825, 5,649,385, 6,786,001 8,341,873, US Patent Publication Nos. 20050138858 and 20050279016, EP Patent Publication No. EP2347759, and PCT Publication No. WO 9615664. Traps containing bait comprising double-stranded RNA for controlling brown recluse spiders are mentioned in EP Patent No. EP0659339, and described as box-shaped and made of a material such as corrugated cardboard with a sticky substance coating the material. At least one Loxosceles species prefers refuges that offer acute angles (Stropa 2010). [0004] Glue-traps have been sold commercially for capture of not only arachnids but also flying insects, rodents, and reptiles. Glue-traps have also been used for estimating the population of beetle infestations (e.g., Hagstrum et al. 1994). In addition, glue-traps have been used to estimate brown recluse populations inside residential housing (Vetter et al. 2002). A search of the existing literature reveals no studies that compare spider trap designs, even though spider populations have been successfully estimated with glue-traps (Sandidge et al. 2005). Many such traps comprise behavior-altering chemicals such as pesticides and chemical attractants. Homeowners, however, are often deterred from using chemical pesticides due to possible health risks and environmental side effects. [0005] Many insects are attracted to light, and traps for such insects utilizing light or food or other chemical attractants as bait have been described. However, brown recluse spiders prefer dark places, and many homeowners prefer not to attract human attention to such traps by using light. [0006] There is a particular need for safe and consistent management for the brown recluse spider, Loxosceles reclusa Gertsch & Mulaik, a venomous spider found in large areas of central, eastern, and southern United States, and considered abundant in Kansas (Sandidge and Hopwood, 2005). This spider is a synanthrope and therefore is commonly found in association with human structures (Schenone et al., 1970). The brown recluse spider is venomous and, although bites are uncommon, when they do occur the bite may develop into a necrotic lesion where tissues around the bite break down, creating a slow-healing wound that may leave significant scarring (Anderson, 1982). Therefore, tolerance for brown recluse spiders in homes is very low and homeowners expect 100% control. [0007] It is estimated that most homes in the area of brown recluse distribution are infested by these spiders, and that they are regularly transported to new homes in building materials or in items moved from other structures (Zurek, 2005). L. recluse has adapted so well to human dwellings that populations can be quite large with one report documenting up to 2,055 brown recluse spiders collected from a 270 m 2 Kansas home in a mere six-month time period (Vetter and Barger, 2002). [0008] The brown recluse presents challenges for pest control professionals because it is so difficult to eliminate from structures. There have been few studies conducted to test the efficacy of modern pesticides and treatment methods for brown recluse spider control and the studies that have been conducted often report inconsistent results (Sandidge and Hopwood, 2005). One of the reasons that L. reclusa is so difficult to eliminate from structures is because of their secretive nature. These spiders are nocturnal, webs are typically built in out-of-the-way areas that are rarely disturbed, including difficult to access areas; locations of spiders will differ with each infestation depending on many variables including the layout of the home, temperature and population size (Sandidge and Hopwood, 2005). Additionally, L. reclusa is known to feed on a wide range of insect and other arthropod prey and has been shown to readily feed on dead prey, including freshly killed, dead several months, and even prey killed with insecticides (Sandidge, 2003). They can also survive a long time without food or water. Brown recluse spiders have been shown to live up to ten months in a controlled setting with no food or water and up to six months with no food, water, or fresh air (Sandidge and Hopwood, 2005). In addition, these spiders are long-lived, with an average lifespan of 646 days for males and 794 days for females, under favorable conditions (Elzinga, 1977). [0009] Attempted management of these spiders has included the use of various fumigants and aerosols, many having no data to show they were effective, and which were often applied haphazardly and excessively. Early pesticide trials were contradictory and a number of the chemicals considered somewhat effective or effective are now restricted or banned in the United States (Norment and Pate, 1968; Gladney and Dawkins1972). For example, Hite et al. (1966) examined the efficacy of 13 topically applied chemicals, including lindane, diazinon, chlordane, malathion, and carbaryl. Of these tested chemicals only lindane, which has since been banned in the U.S., provided significant residual control of the spiders. [0010] There is a need in the art for a trap for spiders and insects, and especially for the dangerous brown recluse spider, that does not use light as an attractant. There is also a need for such traps not containing chemical attractants or other chemical control substances. Because the brown recluse spider is an important arthropod pest in structures, good, safe, consistent control measures are needed in the form of improved methods for controlling their populations in indoor spaces. [0011] All publications referred to herein are incorporated by reference for purposes of written description and enablement. SUMMARY [0012] A trap for spiders and other insects is provided herein that is especially useful for catching brown recluse ( Loxosceles reclusa ) spiders. In embodiments the trap does not comprise chemical attractants or other behavior-modifying environmentally harmful chemicals. In embodiments the trap does not comprise food bait. In embodiments, the trap does not use light to attract spiders or other insects. [0013] In embodiments, the internal volume of the trap is shaped as a triangular prism as shown in FIG. 1 hereof, except that the triangular faces (sides) are open, i.e., are not solid faces. In embodiments, the triangular faces (sides) are solid, or one or more faces are solid with openings, therein, e.g., comprised of separate vertical struts. In other embodiments the trap is shaped as a pyramid. In other embodiments, the trap is shaped as a box. In embodiments at least one face of the spider trap is completely open. In embodiments, the front of the spider trap comprises openings and can be substantially open. In embodiments, one or more side walls of the trap extend beyond the shape formed by the internal volume of the trap. In embodiments the trap comprises at least one flat, planar wall or portion of a wall. In embodiments the trap comprises two parallel flat planar walls or portions of walls. [0014] The spider trap comprises a floor, which in embodiments is rectangular, but can be any other shape. The floor, in embodiments, is disposed horizontally on the floor of a room or on a table or other object. The floor can be completely planar, or be wavy, stepped, or have any other regular or irregular surface features. In embodiments, the floor, back and front of the spider trap are all rectangular in shape. [0015] The spider trap also comprises a back disposed at an angle θ to the floor. In embodiments angle θ is between about 80° and about 100°. The angle should be large enough, at least one inch, to accommodate the height of a typical spider, but no greater than about 100° so as to be able to place to trap flush against a vertical surface, such as a wall, cabinet, etc. In an embodiment the angle between the bottom of the back and the back edge of the floor is about 90°. [0016] The spider trap also comprises a front disposed at an angle φ to the floor and an angle α to the back. The angle φ between the front and the floor should be large enough to allow spiders entry and small enough to keep dimensions on a compact size and in embodiments is between about 35° and about 55°. If the front is comprised of struts as shown in FIGS. 3 and 4 , each strut is desirably at said angle φ to the floor. If the front additionally comprises a horizontal bar at the bottom of the struts as shown in FIG. 4 , between the bottom of the struts and the front edge of the floor, the angle φ of the front with the floor is considered to be the angle of a notional line extending from the bottom of the horizontal bar to the front edge of the floor with the floor. The angle α between the top of the back and the top of the front should be between about 35° and about 55°. It should not be so large that compact trap size is adversely affected or so small that spiders are unable to gain entry. In embodiments, the front of the trap comprises one or more openings. In embodiments, the front of the trap is substantially open. The purpose of the opening(s) is to allow the spider to enter the trap from either the front or the sides of the trap. All walls of the trap can comprise openings sized and shaped so as to permit entry to spiders from any direction from which the spider approaches. The openings can be rectangular in shape, circular, arc-shaped, or any other regular or irregular shape desired. [0017] At least a portion of the floor is covered with a bug adhesive capable of sticking to a spider leg as well as other body parts and is capable of substantially preventing disengagement of the spider therefrom. Bug adhesives such as those used in flypaper are well-known to the art and commercially available, e.g., available from Atlantic Glue and Paste and Glue, Brooklyn, N.Y., ISCA Technologies, Riverside, Calif., and Ningbo Yinzhou Hopson Chemical Industry Co. Ltd., Ningbo, China. The adhesive should retain its adherence properties for at least 3 months; it should be nontoxic to mammals, both pets and people; the MSDS (material safety data sheet) should be supplied with the adhesive and confirm lack of toxicity; and the adhesive should hold a spider fast after contact with any part of the spider. [0018] The inventors have found that no spiders were caught on the vertical portions of commercial traps. Thus, while it does not appear to interfere with the effectiveness of the trap to provide bug adhesive on portions of the trap other than the floor, this is not necessary, and it is advantageous in terms of cost savings and ease of handling of the traps that bug adhesive not be coated on surfaces other than the floor of the trap. [0019] Adhesive-coated surfaces of the trap can be covered with slick, peel-off paper for shipping and handling. [0020] In an embodiment hereof, the inside of the trap is high enough to allow an adult Loxosceles reclusa with a leg span of up to 2.5 inches to walk inside if it is walking vertically along the wall and entering into the back of the trap without lowering itself in height to avoid touching the trap, and spacious enough to capture up to one dozen adult spiders. In embodiments, such traps hereof have a compact size, i.e., an internal volume between about 35 and about 50 cubic inches, and a height of at least about 2.5 inches. [0021] In an embodiment hereof, the area of the trap floor is large enough to catch multiple spiders if spiders are not removed from the trap. In embodiments, traps hereof have a floor area between about 10 and about 24 square inches. [0022] In embodiments such as that shown in FIG. 3 hereof, the traps have a front wall comprised of vertical struts, the struts have a width between about 0.15 and about 0.35 inches, wide enough to provide sufficient load-bearing capacity to support the front and back walls under normal use, but not so wide as to interfere with the spider's ability to enter the glue trap from the front of the trap between the struts. [0023] In embodiments such as that shown in FIG. 4 hereof, the front of the trap has a horizontal bar wide enough to provide sufficient load-bearing capacity to support the front and back walls under normal use, e.g., between about 0.15 and about 0.35 inches. [0024] In embodiments the walls and floor of the trap are fixedly attached to each other; in embodiments they are rotatably attached to each other so as to rotate through an angle of between about 40° and about 50°, and/or the walls can be removably attached to each other, such as by hinges, by a cord such as a cloth or plastic lacing, or by other fastening devices known to the art. They can also be rotatably connected to each other by being made of a flexible material capable of being folded to form a three-dimensional trap structure or portion thereof. In embodiments each wall of the trap is attached to another portion of the trap so as to form a single flat sheet that can be folded to make the three-dimensional trap. In embodiments. In embodiments, adjacent walls need not be fastened to each other if forces of friction or gravity or the buttressing forces of other walls or the floor will keep them in place during use, for example, in embodiments it may not be necessary to secure the front of the trap to the floor. [0025] In embodiments, the spider trap is made from a material that is, or is made from, wood or wood products, e.g., natural wood, cardboard, including corrugated cardboard, paper, and/or chipboard. In embodiments at least some portions of the surfaces of the trap: the back and the struts are rough to provide a surface the spider can easily walk on. [0026] Kits comprising trap components such as solid walls, fasteners, bug adhesive and instructions for their assembly are also provided herein. In embodiments, the trap is provided to consumers as a single foldable piece of material such as paper comprising tabs and slots, adhesive tabs or other attachment features known to the art for ease of assembly. Consumers can thus determine if they want an “open” (flat) trap or if they want to fold it over to prevent children and pets from contact with the bug adhesive, and manufacturers of the traps need only provide a single embodiment to serve both purposes. [0027] In an embodiment, the trap is packaged for sale on a packaging board in the form of a single sheet as shown in FIG. 7 . The trap comprises a back section, a floor section, a front section and a fold-over tab section. Bug adhesive is coated on the floor section of the trap and covered with peel-off paper. A contact adhesive is coated on the fold-over tab and covered with peel-off paper. [0028] A method for making a spider trap having the shape of a triangular prism comprises: providing a floor having front and back edges; coating or partially coating the floor with a bug adhesive capable of sticking to a spider leg; providing a back having a top edge and a bottom edge, sized and shaped so as to be capable of being fastened to the back edge of the floor; fastening the bottom edge of the back to the back edge of the floor such that the back is disposed at an angle θ to the floor; providing a front having a top edge and a bottom edge, the front being sized and shaped to be attached to the top edge of the back; wherein the front comprises openings defined by a series of vertical struts, a series of vertical struts in combination with a horizontal strut disposed along the bottom of the struts, or a solid portion having an “X” or hourglass shape; fastening the top edge of the front to the front edge of the back so that the front forms an angle α with the back; and optionally fastening the bottom edge of the front to the front edge of the floor so that the front forms an angle φ with the floor. [0029] A suitable adhesive can be coated on the floor or portions thereof, and/or other walls of the trap before or after the walls are attached to each other. [0030] Embodiments of the traps hereof having internal volumes with other shapes can be made by methods analogous to those described above. [0031] To use the single-sheet trap, the back section of the trap is folded over toward the center of the trap to form a vertical back, leaving the rest of the trap flat. The front section the trap is folded upward and inward toward the center to form the front of the trap, leaving the floor section flat. The tops of the front and back are brought together. The contact paper is removed from the fold-over tab on the front of the trap and the fold-over tab is folded downward and inward to stick to the outside top edge of the back. [0032] In use, the trap is disposed in an area believed to be a brown recluse spider habitat and allowed to remain there until one or more brown recluse spiders have become stuck to the adhesive coating. To determine whether an area is likely to be a brown recluse spider habitat, the following factors need to be considered: a. Usual geographical habitat: areas of the United States: from southeastern Nebraska through southern Iowa. Illinois, and Indiana to southwestern Ohio. In the southern states, it is native from central Texas to western Georgia and north to Kentucky; b. Preferred surfaces: cardboard, newspaper, lumber; and c. Local habitat: dark, undisturbed places such as shoes, inside dressers, in bed sheets of infrequently-used beds, in clothes stacked or piled or left lying on the floor, inside work gloves, behind baseboards and pictures, in toilets, and near sources of warmth when ambient temperatures are lower than usual; and nearby areas where they can wander in search of mates and prey items. [0036] It is not necessary to bait the trap with food or other attractants. [0037] Spider traps hereof made of biodegradable, non-toxic materials, along with spiders that have been trapped therein, can be left in place in wilderness settings or in urban and household environments can be disposed of with other biodegradable waste. [0038] This disclosure also provides methods for controlling brown recluse spider populations in indoor spaces utilizing spider traps. BRIEF DESCRIPTION OF THE DRAWINGS [0039] FIG. 1 shows a side view of the spider traps hereof. [0040] FIG. 2 shows a perspective view of a spider trap hereof having an X-shaped strut design. [0041] FIG. 3 shows a perspective view of a spider trap hereof having a vertical strut design. [0042] FIG. 4 shows a perspective view of a spider trap hereof having a vertical strut design with a horizontal bar at the bottom. [0043] FIG. 5 shows a perspective view of a flat trap design. [0044] FIG. 6 shows a perspective view of a prior art box trap design used as a control for evaluating the traps hereof. [0045] FIG. 7 illustrates a commercial version of the trap that can be packaged and sold in flat form and folded by the customer to a three-dimensional conformation. DETAILED DESCRIPTION Definitions [0046] A prism is a shape made of two parallel faces that are polygons of the same shape and sides that are parallelograms. [0047] A triangular prism is a prism with triangular faces, e.g., as shown in FIG. 1 . [0048] A pyramid is a shape with a base that is a polygon and triangular sides. [0049] The term “rectangular” as used herein includes square. [0050] The term “vertical” as used herein with respect to trap walls means extending in an upward direction from the floor at any angle. [0051] The term “back” as used herein with respect to the traps hereof refers to a wall having the least number of openings of any other wall of the trap. [0052] The term “front” as used with respect to the traps hereof refers to a vertical wall which is approximately or directly opposite to the back wall if the trap has four or more faces, or if the trap has three faces, it can refer to either adjacent wall. [0053] The term “floor” as used with respect to the traps hereof refers to a horizontal portion of the bottom of the trap. [0054] The term “top” “bottom,” “upward,” “downward,” “above” and “below” are used herein in their usual meaning relative to the force of gravity when a trap is placed with its floor perpendicular to the force of gravity. [0055] The term “side” as used with respect to the traps hereof refers to any face of the internal volume of the trap that is not a front, back or floor. [0056] The term “open” as used with respect to a face of the trap means that there is no wall on that face. [0057] “Substantially open” as used herein with respect to the front of the trap means that solid portions of the front of the trap are disposed so as to be directly over no more than about 50% to about 75% of the area of the floor. [0058] The “internal volume” of the trap is the three-dimensional shape enclosed by the walls of the trap, and if one or more sides are “open,” that is, are without walls, the internal volume of the trap is defined by the edges of the walls adjoining the “open” walls. [0059] The term “substantially preventing disengagement of a spider leg” as used with respect to the capability of bug adhesives used herein means that in at least about 75% of cases in which a brown recluse spider's leg is stuck to the adhesive, the spider will not be able to pull the leg free. [0060] The brown recluse spider, L. reclusa , is sometimes referred to as the violin or fiddleback spider because of the violin-shaped marking on its dorsum. Although bites are rare, the venom can cause serious wounds and infestations should be taken seriously. The brown recluse spider is most common in the south and central states of the United States, especially in Missouri, Kansas, Arkansas, Louisiana, eastern Texas, and Oklahoma. However, the spider has been found in several large cities outside this range. [0061] Brown recluse ( L. reclusa ) spiders prefer dry, dark, undisturbed places, although they do wander in search of mates and prey items. Although reclusive and shy, they have shown a preference for certain surfaces, such as cardboard, newspaper, and lumber, and other Loxosceles species have shown similar preferences (Fischer et al. 2005). Of these choices, cardboard was used in the Example hereof as the most practical and most inexpensive choice for trap construction. [0062] While there are limited options for chemical-free arachnid pest control, glue-traps are one suitable alternative to pesticides. Four novel trap shape designs and one popular glue trap already on the market were tested to determine if one (or more) of the new designs were more likely to catch brown recluse spiders than the existing design. Although this type of trap was most efficient for capturing L. reclusa , it can pose risks in homes with children and pets for obvious reasons. Among the traps with coverings, the vertical strut trap was most preferred by the spiders, and recommended for homeowners with children and pets. [0063] In the specific embodiments depicted in the Figures, it is to be understood that the specific dimensions and relative dimensions of the traps are not essential features of the traps. The specific and relative dimensions can be feely varied to form a wide range of embodiments within the general parameters specified herein. [0064] In embodiments, a kit for making a trap for spiders and other insects is provided comprising the following components: a flat sheet of a foldable wood product comprising: a back section optionally comprising a slit; a floor section integral with said back section at least partially coated with bug adhesive covered with peel-off paper; a front section integral with said floor section, said floor section comprising openings therein; a tab section integral with said front section sized and shaped, in use, to be folded over the top of the back section, said tab section optionally comprising at least a partial coating of contact adhesive covered with peel-off paper; or said tab section optionally being sized and shaped so as, in use, to fit into said slit in said back section; and instructions for configuring said flat sheet into a three-dimensional spider trap. [0065] A method of making the kit is also comprising: providing a flat sheet comprising front, floor, back and tab sections; coating at least a portion of said floor section with bug adhesive; covering at least said coated floor section with peel-off paper; optionally coating said tab section with contact adhesive and covering said coated tab section with peel-off paper; preparing instructions for peeling off said peel-off paper and folding said flat sheet into a three-dimensional spider trap, wherein said instructions are printed on said flat sheet or provided separately; and packaging said flat sheet and instructions for sale. [0066] A method for making a three-dimensional spider trap from such a kit is also provided comprising: removing said peel-off paper from said bug adhesive on said floor section; folding said back section upward and inward with respect to said floor section to form the trap back; folding said front section upward and inward with respect to said floor section to form the trap front; folding said tab section inward and downward with respect to said trap front to fold over the top of said trap back; and securing said tab to the top of said trap back by: inserting it into said optional slit on the trap back; or peeling said optional contact adhesive from said tab and sticking said tab to the top of the back edge of said front. [0067] Further provided herein is a method for catching a brown recluse spider comprising: Identifying a location where brown recluse spiders are likely to be living; disposing a trap of claim 1 in said area; and allowing said trap to remain in said area until one or more spiders have become stuck to the bug adhesive coating on said trap. To determine whether brown recluse spiders are likely to be living in an area, the following factors should be considered: the area should be defined as the approximate area a brown recluse spider will typically roam over; whether or not a brown recluse spider has been spotted in the area; whether a bite suspected of being a brown recluse spider bite has been experienced by a person in the area; whether the area is located in a geographical region known to be a brown recluse spider habitat; whether the area is an area where humans are likely to go; whether the area provides wood-derived materials as likely brown recluse spider habitats; whether the area provides piles of clothing or rubble likely to provide suitable habitats for brown recluse spiders, and other factors known to the art. [0068] The traps can be left in the area until brown recluse spiders have been captured, or if no spiders are captured within a period of about 14 days, it can be assumed the area is not a significant brown recluse spider habitat. [0069] The traps hereof can also be used to estimate the brown recluse spider population in an area by placing them in an area and counting the number of spiders caught therein over a selected period of time. [0070] FIG. 1 shows a generalized side view of spider traps 10 hereof shown in FIGS. 2-4 . In the embodiment shown in FIG. 1 , back 12 has a height of 6.83 inches. Floor 16 has a width of 6.99 inches. Sides 14 can be present as solid walls, or can be completely or partially open or absent. They are triangular in shape and have a height of 6.83 and a width of 6.99 inches. The angle α between back 12 and front 18 , and the angle φ between floor 16 and front 18 in the embodiment illustrated are about 45°, and the angle θ between floor 16 and back 12 is about 90°. Front 18 lies on a plane extending from the top of back 12 to the front of floor 16 . [0071] FIGS. 2-4 depict traps hereof in which fronts 18 comprise openings of varying shapes and sizes. The solid portions of front 18 can be formed as a single piece or made from separate pieces attached to each other. Sides 14 are open rather than being walls in the embodiments depicted in FIGS. 2-4 . [0072] FIG. 2 shows a perspective view of spider trap 10 hereof having an X-shaped or hourglass strut design. The hourglass design is one embodiment of the X-shaped design that includes narrow vertical struts 25 along each vertical edge of front 18 . The X-shaped design can include vertical struts 24 , or such vertical struts can be absent. In the embodiment depicted, back 12 has a height of 6.67 inches, a length of 13.49 inches and a width of 6.99 inches. Front 18 , which is rectangular in shape, has a length of 13.49 inches and a width of 9.53 inches. Floor 16 , coated with a bug adhesive 28 , is visible in this view. Solid portion 22 of front 18 comprises triangular openings 20 bounded by solid portions 22 . In the embodiment shown, the solid portions forming the “X” have a width of 0.795 inches and are connected to or integral with narrow vertical struts 25 . [0073] FIG. 3 shows a perspective view of spider trap 10 hereof having a vertical strut design. Floor 16 , coated with bug adhesive 28 (shown as dotted lines) is visible in this view. Vertical openings 20 a are defined by the solid portion of front 18 which is composed of separate full-length vertical struts 24 . In the embodiment shown, back 12 has a height of 6.67 inches and a length of 13.49 inches. Floor 16 has a width of 6.99 inches and a length of 13.49 inches. In the embodiment shown, two narrow vertical struts 25 are disposed at the left and right ends of trap 10 , and three wider vertical struts 24 are evenly spaced between them, defining vertical openings 20 a . The vertical struts 24 depicted have a length of 8.26 inches and a width of 0.25 inches and extend from the top of back 12 to the front of floor 16 . [0074] FIG. 4 shows a perspective view of spider trap 10 hereof in which front 18 comprises partial-length vertical struts 24 a , connected at their lower ends to horizontal bar 26 . Floor 16 , coated with bug adhesive 28 is visible in this view. Partial-length vertical struts 24 a define vertical openings 20 a . Horizontal bar 26 is disposed along the bottom of vertical slates 24 a , and spaced apart from the front edge of floor 16 so as to define horizontal opening 20 b . In the embodiment shown, back 12 has a height of 6.66 inches and a width of 13.49 inches. Floor 16 has a width of 6.99 inches and a length of 13.49 inches. Front 18 has a length of 13.49 inches and a width of 9.53 inches. Horizontal bar 26 has a width of 0.795 inches and horizontal opening 20 b has a width (vertical height) of 2.54 inches. [0075] FIG. 5 shows a perspective view of a prior art Catchmaster™ flat trap design comprising a flat, rectangular substrate 30 on which bug adhesive 28 is coated. In the embodiment shown, substrate 30 has a length of 13.49 inches and a width of 6.99 inches. [0076] FIG. 6 shows a perspective view of a prior art Catchmaster™ box trap design used as a control for evaluating the trap designs depicted in FIGS. 2-4 . In the embodiment shown, the back of the trap has a height of 3.49 inches, a length of 13.34 inches. The front of the trap has a height of 2.54 inches and a length of 13.54 inches. [0077] FIG. 7 illustrates a commercial version of trap 10 hereof that can be packaged and sold in the form of a flat sheet and folded by the customer into a three-dimensional conformation along the horizontal lines depicted between the trap sections. Trap 10 can be mounted on a packaging board 36 for sale. The trap comprises a back section 12 , a floor section 16 , and a front section 18 . Floor section 16 is coated with bug adhesive 28 , depicted by dotted lines, and then covered with peel-off paper 32 . Front section 18 comprises full-length vertical struts 24 separated by vertical openings 20 a . Fold-over tab 34 runs horizontally along the bottom of vertical struts 24 and is coated with contact adhesive 29 and covered with peel-off paper 32 . [0078] To use trap 10 shown in FIG. 10 , the customer removes it from packaging board 36 , and removes peel-off paper 32 from floor 16 and fold-over tab 34 . The customer folds back 12 upward and inward to about a 90° angle and folds front 18 inward and upward so that the top of front 18 is adjacent to the top of back 12 , leaving floor 16 horizontal and allowing tab 34 to extend beyond the top of back 12 . The customer then folds tab 34 down so that contact adhesive 29 thereon secures it to the top of the outside edge of back 12 . This creates a three-dimensional trap structure which can be placed in a suitable area for trapping spiders. Examples Example 1 Spider Trap Construction [0079] It was hypothesized that glue traps employing cardboard would be suitable for attracting and trapping Loxosceles reclusa spiders. The motivation of this study was to determine improved three-dimensional shape(s) of cardboard traps for catching brown recluse spiders. Although reclusive and shy, L. reclusa have shown a preference for certain surfaces, such as cardboard, newspaper, lumber, and other Loxosceles species have shown similar preferences (Fischer et al. 2005). Of these choices, cardboard was chosen as the most practical and inexpensive choice for trap construction. [0080] The effectiveness of several three-dimensional glue-trap shapes for trapping Loxosceles reclusa Gertsch and Mulaik (Araneae: Sicariidae), was investigated using four novel glue-trap shape designs, which were compared to an existing design currently on the market. These four novel and one standard shape designs were tested using pairwise comparisons. The most effective trap design was a flat glue-trap with no covering. The next most-effective trap was a trap with a front face comprising full-length parallel vertical struts. The trap comprising partial-length vertical struts with a horizontal bar was the third most effective embodiment. Materials and Methods [0081] All L. reclusa used in this study were caught in central or south-central Missouri, USA. While in the laboratory, they were fed a diet consisting of domestic house crickets ( Achetus domesticus ) and various species of shorthorned grasshoppers. A mixture of adult and juveniles spiders were used. Glue-trap designs were made using modified Catchmaster™ glue traps (catchmaster.com) cut into 6.67×13.49 cm rectangles and laser-produced cardboard cutouts from The Center for Rapid Product Realization at Western Carolina University. [0082] The experimental roofed traps used 0.03″ non-corrugated chipboard pad cardboard (Uline, uline.com) laser cut to the specifications shown in FIGS. 1-4 . There were a total of five trap designs: flat (6.67×13.49 cm rectangle with no cardboard attached, FIG. 5 ), and traps with fronts having X-shaped (hourglass) struts ( FIG. 2 ) full-length vertical struts ( FIG. 3 ), partial-length vertical struts with a horizontal bar near the bottom ( FIG. 4 ), and regular Catchmaster™ traps ( FIG. 6 ), which were used as the control. The base of the trap was the same (6.67×13.49 cm rectangle) in each of the five designs. [0083] For a paired comparison of traps, two spiders of the same gender and/or age group (males with males, females with females, juveniles with juveniles) were placed into a plastic bin measuring 30.48×45.72×30.48 cm and left to acclimate for approximately 12 hours. At that point, two traps of different designs were placed in the bin, one on either end, about 2.54 cm from the wall. Spiders were left for another 12 hours, and at the conclusion of that period, it was noted in which trap, if any, the spiders were caught. Each trap pairing was tested at least 50 times. Only spiders that did not choose a trap during their first experiment were used again. The experimental comparisons were performed in a laboratory setting to cut down on external stimuli that might have influenced trap choice, such as odors, air currents, temperature, etc. Statistical Analysis [0084] A Bradley-Terry model was fitted for paired comparisons in SAS© 9.2 (sas.com) with PROC LOGISTIC and PROC GENMOD, where ties (spider prefers neither trap) are removed. The Deviance and Pearson Goodness-of-Fit Statistics in PROC LOGISTIC yield p-values of 0.09 and 0.10 respectively, the Hosmer-Lemeshow p-value is 0.21, and the Lagrange Multiplier Statistic for non-intercept in PROC GENMOD yields a p-value of 0.03, which suggests that there may be a problem with the fit of the Bradley-Terry model. Results and Discussion [0085] The estimated preference probabilities obtained from the fitted model are listed in Table 1. [0000] TABLE 1 Estimated preference probabilities obtained from the fitted model. Preferred trap design Design preferred over p X Vertical 0.43 Horizontal 0.45 Flat 0.25 Control 0.5 Vertical Horizontal 0.53 Flat 0.31 Control 0.58 Horizontal Flat 0.29 Control 0.55 Flat Control 0.75 The probabilities suggest the following ordering of the five traps for catching L. reclusa (least preferable to most preferable): Control< X trap< horizontal bar trap< vertical strut trap< flat trap. [0086] In addition to the possible problem with the model mentioned above, there was a fairly high percentage of ties in the data set (Table 2). [0000] TABLE 2 Number of Trials and Ties Comparison Number of Trials Number of Ties X vs. Vertical 55 23 X vs. Horizontal 58 23 X vs. Flat 63 16 X vs. Control 50 13 Vertical vs. Horizontal 51 12 Vertical vs. Flat 50 13 Vertical vs. Control 50 9 Horizontal vs. Flat 55 9 Horizontal vs. Control 50 3 Flat vs. Control 50 14 [0087] As a result, an extended Bradley-Terry analysis that adjusted for ties was implemented in SAS. Here, a tie was interpreted to mean that each trap receives one-half of a choice. For example, assume that 50 trials were performed for a pair of traps, and the first trap was chosen 23 times, the second trap was chosen 22 times, and neither trap was chosen 5 times. In the adjustment for ties, pseudo-data were generated, where the first and second traps were chosen 25.5 and 24.5 times, respectively. Turner and Firth (2012) find that this simple and intuitive approach to handling ties works well in practice and generally yields results very similar to those obtained from much more sophisticated analyses, which have the disadvantage of being much harder to implement and interpret. [0088] A Bradley-Terry model for paired comparisons was fit with the pseudo-data values in SAS. The Deviance and Pearson Goodness of-Fit Statistics in PROC LOGISTIC yielded p-values of 0.17 and 0.18 respectively, the Hosmer-Lemeshow p-value was 0.35, and the Lagrange Multiplier Statistic for non-intercept in PROC GENMOD yielded a p-value of 0.06. Obtaining insignificant p-values for each of the four goodness-of-fit procedures suggests that the extended Bradley-Terry model fits the data well. [0089] The estimated preference probabilities obtained from the adjusted analysis are listed in Table 3. [0000] TABLE 3 Estimated Preference Probabilities Obtained from the Adjusted Analysis Preferred trap design Design preferred over p X Vertical 0.45 Horizontal 0.47 Flat 0.32 Control 0.51 Vertical Horizontal 0.52 Flat 0.36 Control 0.56 Horizontal Flat 0.34 Control 0.54 Flat Control 0.69 [0090] The probabilities yielded the following ordering of the five traps for catching L. reclusa (least preferable to most preferable): Control< X trap< horizontal bar trap< vertical strut trap< flat trap. [0091] In summary, analyses that excluded ties and analyses that included ties agreed on the same ordering of the traps. The flat trap was chosen more than the other traps in the pairwise comparisons (Table 4). [0000] TABLE 4 Trap Comparisons Trap Pairings X Vertical Horizontal Flat Control X vs. Vertical 22% 36% X vs. Horizontal 24% 32% X vs. Flat 16% 56% X vs. Control 46% 28% Vertical vs. Horizontal 36% 40% Vertical vs. Flat 30% 44% Vertical vs. Control 44% 38% Horizontal vs. Flat 14% 72% Horizontal vs. Control 54% 40% Flat vs. Control 46% 26% [0092] However, the flat trap was the least user-friendly trap of those tested, since there was no barrier to prevent accidental glue contact from non-arthropod victims such as children, pets, etc. The other traps had some type of cardboard “roof” over the glue part, serving as a physical deterrent for unwary or inquisitive animals and/or children. The standard, unmodified control trap design performed poorly against all of the modified designs, even though it had a much larger glue perimeter (55.88 cm) and glue surface area. Exposed glue perimeters for the X, all vertical, vertical with horizontal bar, and flat traps were 18.42, 17.78, 19.69, and 36.83 cm, respectively. Perimeter comparisons can yield only a partial explanation for the differences in trap selection, because the flat trap had 53% more exposed perimeter than the other modified traps, yet it was chosen 14% more often than the horizontal bar trap design. It also outperformed the control trap, which had 66% more exposed perimeter than the flat trap. Also, the cardboard backs and struts on the other three modified traps may have facilitated spider escape, as there was no glue on those areas. The experimental roofed traps were constructed of chipboard cardboard, a different material than the commercial roofed traps, so the different results obtained with the experimental traps vs. the commercial traps cannot be ascribed solely to different design shapes. Example 2 Comparison of Vertical Trap with Flat Traps [0093] The objective of this study was to compare the performance of the vertical spider trap of the present invention with three commercial glue traps, Catchmaster (spider and insect trap, www.catchmaster.com/wpcproduct/mouse-insect-glue-boards/), PIC (GMT-2F Mouse Glue Board, www.amazon.com/PIC-GMT-2F-Mouse-Board-2-Pack/dp/B0037Z1F9A), and Tomcat (Glue Board, www.tomcatbrand.com/glue_boards.html). Materials and methods were as described in Example 1 except that the present vertical trap was tested against the three competing flat traps and 100 trials were conducted. In 41 of the 100 trials no spider was caught. Results are provided in Table 5. [0000] TABLE 5 Comparison of Vertical Trap with Flat Glue Traps PIC Vertical Catchmaster Triangular prism Tomcat (This Rectangular (solid front, back Rectangular Type of Trap Invention) box and floor) box No. of trials 21 17 14 7 in which spider was caught The results show superior performance by the novel vertical trap hereof. [0094] The foregoing illustrates spider traps hereof and methods and kits for making them, as well as methods of catching spiders and reducing spider populations in indoor areas. The descriptions, examples and illustrations provided are not intended as an exhaustive description of every possible embodiment covered by the claims. Art-known and obvious equivalents to elements, components structures, parameters, and method steps are included within the scope of this invention which is defined by the attached claims. REFERENCES [0000] U.S. Pat. No. 4,048,747, F V Shanahan et al., issued Sep. 20, 1977 for Baseboard Trap for Crawling Insects. U.S. Pat. No. 4,052,811, E B Shuster, issued Dec. 11, 1977 for Insect Catching Device. U.S. Pat. No. 4,244,134, H J Otterson, issued Jan. 13, 1981 for Disposable Pest Trap. U.S. Pat. No. 4,324,062, F A Schneider, issued Apr. 13, 1982 for Human Insect Trap for the Live Capture of Spiders and the Like. U.S. Pat. No. 4,608,774, DA Sherman, issued Sep. 2, 1986 for Construction for Roach Traps. U.S. Pat. No. 4,819,371, HL Cohen, issued Apr. 11, 1989 for Insect Traps. EP 0 659 339 B1, Nitto Denko, Published Jun. 28, 1995, for Adhesive insect trapping housing. U.S. Pat. No. 5,513,465, S W Demarest, et al., issued May 7, 1996 for Method and Apparatus for Catching Insects. WO 9615664, D G Anderson, Published May 30, 1996, for Light Trap for Insects. U.S. Pat. No. 5,572,825, M J Gehret, issued Nov. 12, 1996 for Glue Trap. U.S. Pat. No. 5,649,385 M J Acevedo, issued Jul. 22, 1997 for Insect Trap and Method. U.S. Pat. No. 6,786,001, AGSP Piper et al. issued Sep. 7, 2004 for Insect Trap. US2005/0138858, W. Lyng Published Jun. 30, 2005 for Trap for Crawling Insects. US2005/0279016, W. Lyng Published Dec. 22, 2005 for Floating Aquatic Emergence Trap. EP 2 347 759 A2, de VGen, N V, Published Jul. 27, 2011 for Methods for controlling pests using RNAi. U.S. Pat. No. 8,341,873, S. Frisch, issued Jan. 1, 2013 for Portable Insect Trap. Anderson, P. 1982. Necrotizing spider bites. Practical therapeutics. 26(3): 198-203. Big-H Trap bighproducts.com/traps.htm, downloaded Jul. 9, 2013. Brown Recluse Spider Traps p. 5, www.brown-recluse.com/ Downloaded Jul. 9, 2013. Catchmaster Catalog pages, Catchmaster.com, Downloaded Jul. 19, 2013. Catchmaster Glue Boards, catchmasterglueboards.com downloaded Jul. 18, 2013. Catchmaster Mouse and Insect Glue boards, www.catchmaster.com/wpcproduct/mouse-insect-glue-boards/, downloaded Aug. 4, 2014. Davis, H N, et al. Residual effect of insecticide treatment plus use of sticky traps on brown recluse spiders (Araneae: Sicariidae) on two surfaces, Toxicon. In Press. Elzinga, R. J. 1977. Observations on the longevity of the brown recluse spider, Loxosceles reclusa Gertsch and Mulaik. J. Kansas Entom. Soc. 50(2): 187-188. Fischer M A, Vasconcellos-Neto J. 2005. Microhabitats Occupied by Loxosceles intermedia and Loxosceles laeta (Araneae: Sicariidae) in Curitiba, Paraná, Brazil. Journal of Medical Entomology 42(5): 756-765. Gladney, W. J., and C. C. Dawkins. 1972. Insecticidal tests against the brown recluse spider. J. Econ. Entomol. 65: 1491-1493. Hagstrum D W, Dowdy A K, Lippert G E. 1994. Early detection of insects in stored wheat using sticky traps in bin headspace and prediction of infestation level. Environmental Entomology 23: 1241-1244. Hite, J M, et al. 1966. The biology of the brown recluse spider. Arkansas Experiment Station, Bulletin 711, p. 1-26. Norment, B. R. and T. L. Pate. 1968. Residual activity of diazinon and lindane for control of Loxosceles reclusa . J. Econ. Entomol. 61: 574-575. PIC Mouse Glue Board, www.amazon.com/PIC-GMT-2F-Mouse-Board-2-Pack/dp/B0037Z1F9A, downloaded Aug. 4, 2014. Sandidge, J. S. 2003. Scavenging in brown recluse spiders. Nature 426: 30. Sandidge J S, Hopwood J L. 2005. Brown recluse spiders: A review of biology, life history and pest management. Transactions of the Kansas Academy of Science 108(3): 99-108. Schenone, H., et al. 1970. Prevalence of Loxosceles laeta in houses in central Chile. Am. J. Troup. Med. Hyg. 19: 564-567. Stropa A A. 2010. Effect of architectural angularity on refugia selection by the brown spider, Loxosceles gaucho . Medical and Veterinary Entomology 24: 273-277. Tomcat Glue Boards, www.tomcatbrand.com/glue_boards.html, downloaded Aug. 4, 2014. Turner H, Firth D. 2012. Bradley-Terry Models in R: The BradleyTerry2 Package. Journal of Statistical Software 48(9): 1-21. Vetter, R S, Barger D K. 2002. An infestation of 2,055 brown recluse spiders (Araneae: Sicariidae) and no envenomations in a Kansas home: Implications for bite diagnosis in regions of North America where the spider is not endemic. Clinical Infectious Diseases 39(6):948-951. 2002. Zurek, L. 2005. Spiders and Scorpions. Kansas State University Agricultural Experiment Station and Cooperative Extension Service. MF-771: 1-3.

A trap for spiders and other insects is provided. The trap is especially useful for catching brown recluse ( Loxosceles reclusa ) spiders, whose bites are extremely harmful. The trap need not utilize chemical attractants or other behavior-modifying environmentally harmful chemicals, or food bait or lights to attract the spiders. In embodiments, the internal volume of the trap is shaped as a triangular prism with open triangular faces and openings in the front. At least a portion of the floor is coated with bug adhesive. The trap can be packaged as a kit including a flat sheet that can be folded a three-dimensional shape. In a useful embodiment the front includes spaced vertical struts. Methods and kits for making using the traps are also provided.

BACKGROUND OF THE INVENTION The present invention relates to infusion members and more particularly to a novel multi-angle U-shaped hub for an infusion member. Conventional medical practice often requires an intravenous infusion to be performed to allow blood, nutriments or other desirable fluids to be fed directly into the vascular system of a patient being treated. A venipuncture is performed at a site on the patient's body and a hollow infusion member is inserted therethrough. Typically, a length of tubing is attached between the infusion member and a supply bottle located in the vicinity of the patient. It is extremely important to prevent lateral movement of the infusion member relative to the venipuncture site, to reduce abrasion and laceration of the flesh around the venipuncture site and so minimize its irritation and susceptibility to phlebitis, and to prevent inadvertent withdrawal of the infusion member, to minimize hematoma or blood loss. It is known to provide a structure, adjacent to the junction of the infusion member and tube, to be grasped during the venipuncture operation. It is also known to utilize the structure to provide a surface for taping the junction region to the patient's body, after the infusion member had been inserted, to reduce the undesirable lateral movements thereof. Desirable infusion apparatus should also utilize a structure allowing the infusion member and tube to be manufactured in an axially aligned condition, and still provide a doctor or technician complete choice of the final angular orientation of the infusion tube with respect to the infusion member. A medical practitioner, especially when preparing a patient for surgery, requires a choice of angles of the infusion tube relative to the infusion member. Various surgical procedures require that the infusion tube: remain axially aligned with the infusion member, as when the intravenous supply is positioned toward the lower extremity of the patient; have a 90° bend with respect to the axis of the infusion member, as when filters are attached thereto; have a 135° bend with respect to the infusion member axis, to allow the flexible tube to point towards the head of the operating table when the venipuncture site is situated in the outstretched arm of the patient; or have a 180° bend if the arm is at and parallel to the patient's side and the intravenous source is near the head of the patient. Thus, an infusion member hub capable of maintaining the flexible infusion tube at one of a plurality of angles relative to the axis of the infusion member, yet minimizing the radial pressure on the tube to prevent a pinch effect and subsequent decrease of both internal cross-section of and flow through the tube, is desirable. BRIEF SUMMARY OF THE INVENTION In accordance with the invention, a multi-angle U-shaped hub for an infusion member includes a plurality of clips generally equally spaced about the periphery of the hub and a projection extending from one corner of the hub to receive the junction of the infusion member, such as an intravenous needle, a sheathed needle, a cannula, a catheter, a styletto-catheter or the like, with a flexible length of infusion tube. The infusion tube and infusion member are initially in axial alignment. Each of the hub clips has a radially disposed slot, of a width less than the outer diameter of the tube, which slot communicates with a generally circular aperture having a diameter at least equal to the outer diameter of the flexible tube and formed in each hub clip parallel to the hub periphery. The infusion tube is inserted through the slot into the aperture of a successively larger total of the hub clips to enable the tube to be bent through and maintained at successively greater angles relative to the axis of the infusion member. The diameter of the aperture is selected to prevent pinching of the wall of the infusion tube. In a preferred embodiment, a semi-circular hub is provided with four hub clips. Each clip is positioned to have a 45° angular rotation along the curved hub periphery relative to the adjacent hub clips or to the hub protrusion. In another preferred embodiment, the hub protrusion encloses the junction between the flexible infusion tube and a male standard cannula connector to provide the advantages of the multi-angle hub while enabling the practitioner to select one of a variety of standard rigid or flexible cannulae for attachment to the standard connector. In still another preferred embodiment, a shaped collar is formed about the junction of the infusion member and infusion tube, or an intermediate portion of an infusion combination. The hub protrusion includes a flanged recess adapted to forcefittedly receive and lock the shaped collar to the multi-angle hub, thereby enabling insertion and removal of one of a plurality of infusion combinations, and reuse of the hub and/or infusion member. In yet another preferred embodiment, the infusion member is a single lumen catheter having a slidably retractable but non-removable stylette contained in a secondary channel formed completely within the catheter wall; the hub protrusion includes a cooperatively formed recess in communication with the stylette channel for enabling the passage of the proximal end of the stylette through the protrusion whereby the sharp stylette tip may be withdrawn a short distance into its secondary channel after the venipuncture has been performed. This novel styletto-catheter may be utilized separate from the novel hub. Accordingly, it is an object of the present invention to provide a novel hub for an infusion member and infusion tube. It is another object of the present invention to provide a novel infusion hub allowing an infusion tube to be maintained at one of a plurality of angular orientations with respect to the axis of an infusion member. It is yet another object of the present invention to provide a hub having means for detachably receiving one of a variety of infusion tube-infusion member combinations to provide for reuse of the hub. It is a further object of the present invention to provide a novel styletto-catheter having its stylette slidably received within a secondary channel formed within the wall of a single lumen catheter. It is a still further object of the present invention to provide a styletto-catheter in apparatus allowing a flexible infusion tube to be maintained at one of a plurality of angular orientations with respect to the axis of the catheter lumen. These and other objects of the present invention will become apparent in reading the accompanying detailed description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a multi-angle U-shaped hub for an infusion member and infusion tube in accordance with the principles of the present invention. FIG. 1a is a plan view of the hub of FIG. 1 and illustrating the manner in which the infusion tube is retained at a plurality of angular orientations with respect to the axis of the infusion member; FIG. 2 is an enlarged cross-sectional view of the hub taken along line 2--2 of FIG. 1; FIG. 3 is an enlarged cross-sectional view of the hub, infusion member and infusion tube taken along line 3--3 of FIG. 1; FIG. 4 is an exploded perspective view of the hub utilizing a novel styletto-catheter and illustrating a method for the manufacture thereof; FIG. 5 is a plan view of another embodiment of hub having means for detachable mounting an infusion combination to the hub protrusion, and a partially-sectionalized view of one such infusion combination; FIG. 6 is an enlarged cross-sectional view of the hub taken along line 6--6 of FIG. 5; FIG. 7 is an exploded perspective view of another means for detachably mounting an infusion combination to a protrusion on the periphery of the multi-angle hub of the present invention; FIGS. 8 and 8a are cross-sectional views of the hub and novel styletto-catheter in the extended and retracted conditions, respectively; FIG. 9 is a cross-sectional view of the styletto-catheter taken along line 9--9 of FIG. 8a; FIGS. 9a and 9b are cross-sectional views of alternative embodiments of the styletto-catheter; FIG. 10 is a cross-sectional view of another embodiment of a styletto-catheter in accordance with the principles of the invention and for use separate from the U-shaped hub; FIG. 11 is a cross-sectional view of the styletto-catheter taken along line 11--11 of FIG. 7; and FIGS. 11a and 11b are cross-sectional views of alternative embodiments of the styletto-catheter utilizing the principles of the present invention. DETAILED DESCRIPTION OF THE INVENTION Referring now to FIGS. 1-3, a preferred embodiment of multi-angle U-shaped hub 10 comprises a generally semicircular portion 11 formed of a relatively inflexible and lightweight material, such as plastic or the like, and having generally parallel upper and lower smooth surfaces 11a and 11b, respectively. A projection 12 integrally extends from a portion of hub periphery 14 adjacent to a first corner 11c formed between the periphery and the diametric edge 16. A plurality of clips 18a-18d respectively extend radially outward from hub periphery 14. A hollow infusion member 20, such as a needle; a cannula; a catheter with or without centrally placed removable trochar, stylette or needle; a sheathed needle; a styletto-catheter or the like, has a bevelled or flat distal end 21 and a proximal end 22 having attachment means 22a such as a flared skirt, hub or the like. A length of flexible infusion tubing 25 has an outer diameter D 1 . One end 27 of the tube includes hub means 28, such as a standard universal female intravenous tube coupling having a converging interior passage 29 for force-fittingly receiving the nipple, such as a Luer fitting or the like, of a tube running from an intravenous supply bottle or the like (not shown for reasons of simplicity). The proximal end 22 of infusion member 20 is adapted to closely receive and form a substantially liquid-tight seal to a forward end 30 of tube 25. It should be understood that a separate infusion member 20 and infusion tube 25 are shown for the purposes of illustration only; the wall and channel of tube 25 may extend in uninterrupted fashion completely through hub protrusion 12 to form a flexible cannula, as the hollow infusion member 20. In general, hub protrusion 12 receives an infusion combination, which combination is defined herein as any infusion tube in fluid-flow connection with either an infusion member or means for coupling an infusion member to the tube. Usually a more rigid stylette or hollow needle is kept within the infusion member during insertion and removed after insertion in the vein. Hub protrusion 12 surrounds and encases the junction between infusion member proximal end 22 and infusion tubing forward end 30. The protrusion is preferably molded around the previously joined infusion member and tube to provide a high quality liquid-tight seal. Each hub clip 18 has a selected value of angular rotation along curved periphery 14 with respect to both the adjacent hub clips and to a reference line 12a at protrusion 12. Thus, a first clip 18a is situated at an angle α with respect to reference line 12a; a second clip 18b is situated with an angle β with respect to first clip 18a; a third clip 18c is situated with an angle γ with respect to second clip 18b; and a fourth clip 18d is situated with an angle δ with respect to third clip 18c, for hub having four hub clips 18. It should be understood that this novel hub for infusion member may be provided with one clip, or plurality of clips 18 and that the angles formed between adjacent clips and between a clip and the hub protrusion may be selected as required for a range of end uses. In a preferred embodiment, the hub includes four clips having equal angles with each other and with reference line 12a, i.e., α=β=γ=δ, and each angle is approximately fourty-five degrees. Each hub clip 18 has an aperture 35, of diameter D 2 , formed therethrough parallel to hub periphery 14. Aperture diameter D 2 is selected to be substantially equal to, but never less than, the outer diameter of D 1 of infusion tube 25, whereby pressure tending to pinch infusion tube 25 partially or completely closed is avoided when the infusion tube is positioned within aperture 35. A slot 36 is formed through the radially outermost remaining portion of clip 18 to allow tube 25 to be pressed into aperture 35. Slot 36 has a gap distance G selected to allow tube 25 to pass therethrough only when tube 25 is forcibly compressed, whereby the tube is maintained within the aperture if external compression force is not applied. Preferably, the material utilized for the formation of the hub, and particularly for clips 18, is highly resilient to absorb shock forces tending to tear tube 25 from each clip 18 through which the tube has been positioned. In use, opposite surfaces 11a and 11b of the hub are grasped to allow insertion of infusion member 20. A solid or hollow trocar member 35 may be required to perform the puncture, particularly if the infusion member 20 is a flexible catheter or the like. The bevelled cutting edge 35a of the trocar is inserted through the axially aligned lumens of tube 25 and infusion member 20 to extend forward of infusion member forward end 21. After the puncture has been performed, and the trocar removed, infusion tube coupling 28 is attached to a supply bottle or the like (not shown). It should be understood that known means may be employed with tube 25 and its coupling 28 to temporarily seal the lumen and prevent liquid outflow after the puncture has been completed but before connection has been made to the coupling. One of smooth hub surfaces 11a or 11b is then placed against the patient's skin and the hub is secured in place by means external to the hub (not shown). Alternatively, surfaces 11a and/or 11b may be slightly concave to make pinching more comfortable. And in another alternative, one or both of hub surfaces 11a, 11b are coated with a layer of adhesive material 38 and covered with a protective layer 39; protective layer 39 is removed and hub 10 is pressed against the patient's skin to allow adhesive layer 38 to adhere thereto and hole the hub in place to absorb the forces of lateral movement. Having inserted infusion member 20 and secured hub 10 to the patient's body, the physician or medical technician now bends tube 25 into position against the slot 36 formed in the first clip 18a and presses the tubing therethrough to be retained within aperture 35 (FIG. 1a); the axis B of infusion tube 25 is now held at a bend angle θ with respect to the axis A of infusion member 20, having been gently bent at region 25a to prevent buckling of the tube wall and ensuing diminution of infusion flow. A larger bend angle θ is achieved as tube 25 is engaged within the apertures of clips 18 having greater angles of rotation from protrusion 12. Thus, in the illustrative examples, θ is 45° when tube 25 is held only by clip 18a. Tube 25' forms an angle θ equal to 90° when positioned in the apertures of both clips 18a and 18b; θ = 135° when tube 25" is positioned in the apertures of clips 18a, 18b and 18c; and θ = 180° when tube 25'" is positioned through the apertures of all four clips 18a-18d. In one preferred embodiment (FIG. 4), multi-angle hub 10 is formed of a semi-circular blank 50 having a thickness T 1 . Protrusion 51, having a greater thickness T, is formed along the curved periphery of member 50 and encloses the junction between an infusion member 52, such as a styletto-catheter, and an infusion tube 53. Each or a pair of matched clip members 55a and 55b has a central semi-circular portion 56 and 56', respectively, of thickness T 2 and have a like plurality of fingers 57 extending from their respective curved peripheries 56a and 56'a of portions 56 and 56' -- the position of clip fingers 57a-57d on each of periphery 56a, 56a' being complementary about an axis C passing through the midpoint of each diametric side 56b', 56b' and perpendicular thereto. Each clip finger 57 includes a radially extended portion 58 integrally joined to a semi-circular portion 56 or 56' and a second portion 59 extended perpendicular to the plane of the portion at the radially outermost end of first portion 58. A curved portion 60 fills the inside corner formed by portions 58 and 59 and has a radius of curvature essentially equal to one-half the outer diameter D 1 of tube 25. A matched pair of clip members 55a and 55b are arranged with their respective clip finger second portions 59 facing each other, and are fastened by means of a suitable cement, solvent, thermal weld or the like to opposite faces 50a, 50b of hub member 50. It should be evident that a large selection of final hub assemblies 10 can be formed by manufacturing a plurality of different hub members 50 and another plurality of different matched pairs of clip members 55. Each hub member 50 has a particular combination of infusion member 52 and length and type of infusion tube 53 and may be utilized with a pair of matched clip members 55 selected from the plurality of such clip member pins having the same radius but utilizing different numbers and positions of clip portions 57. The clip member thickness T 2 and hub member thickness T 1 are selected such that T 1 + T z = T, the protrusion thickness, to yield a hub having smooth upper and lower surfaces 11a, 11b (FIG. 2). The length L of each clip second portion 59 is selected according to the formula L = 1/2 (T-G) to provide for a suitable slot 36 through which tube 25 may enter the clip. Referring now to FIGS. 5 and 6, wherein like reference numerals are utilized for like elements, another embodiment of multi-angle infusion hub 10' includes a hub protrusion 12' integrally extended from a portion of hub periphery 14 adjacent to the first corner 11c formed between the periphery and diametric edge 16. Hub protrusion 12' has a cross-section similar to each hub clip 18 and includes an aperture 35 of diameter D 2 formed therethrough parallel to hub periphery 14 and a slot 36' formed through the radially outermost remaining portion of hub protrusion 12'. An intermediate portion 25a of tube 25', between distal end 30' and proximal end 27', is forcibly compressed and inserted within protrusion aperture 35' and maintained therein by the resiliency of the material forming protrusion 12', in the absence of external compression force. A male standard cannula connector 62 has a converging forward portion 62a and a tube coupling portion 62b of reduced diameter force-fittedly received within the lumen of distal end 30 of infusion tube 25'. Portion 62 may also be cemented, bonded by solvent or thermally welded to distal end 30. The outer diameter D 3 of coupling portion 62b is at least equal to the bore diameter of flexible tubing 25', to insure a liquid-tight connection therebetween. The standard connector 62 is adapted to accept a wide variety of rigid or flexible standard cannulae (not shown). If force-fittedly secured, the selected cannula may be removed from standard connector 62 to allow the hub, tube and connector combination to be reused, or the tube-connector combination may be pressed outwardly from channel 35' and be disposed of, allowing reuse of hub 10'. Referring now to FIG. 7, a collar 64 has a flat upper surface 64a of width W 1 and a tapering lower portion 64b having a keel-like projection 64c to control rolling or turning. The collar may be molded around the junction between an infusion member and infusion tube to provide the required liquid-tight connection, or, as illustrated, may be molded about an intermediate portion of a continuous length of flexible infusion tube 25" to form part of an infusion combination. Hub member 10" has a flat surfaced diametric edge 16" and includes a hub protrusion 12" having a recess 65 of similar cross-section to collar 64 including keel 64c. Recess 65 is formed into protrusion 12" perpendicular to flat surface 16". A circular channel 35" axially extends in either direction from recess 65 and a slot 36" is formed through the radially outermost remaining portion of hub protrusion 12" to allow tube 25" to enter channel 35". A flanged edge 66 is formed along the length of the rectangular opening of recess 65 in the radially outermost surface 12b of hub protrusion 12'. The flanged edges reduce the width of recess 65 to a width W 2 less than the width W 1 of the remaining portion of the recess and of collar 64. In use, collar 64 is pressed into recess 65 with its keel 64c and then its converging portion 64b initially entering the recess. The insertion is aided by the resiliency of the material utilized for the hub member. Upon further application of force, collar 64 fully enters recess 65 and flange portion 66 resiliently snap-locks over peripheral edge portions of the top surface 64a of molded collar 64, to prevent radial movement of collar 64 within recess 65, while the remaining portions of hub protrusion 12" prevent axial and rotational movement of the collar and the encased tube 25'. The resilient material of hub protrusion 12" is forced apart adjacent top surface 12 to allow collar 64 and the attached tube 25" to be removed from recess 65 and discarded whereby multi-angle hub 10" may be reused. I have found that a particularly advantageous infusion member for use with my novel, multi-angle U-shaped hub 10 is a styletto-catheter 52 (FIG. 8) having a generally flexible infusion portion 70 integrally joined with infusion tube 53 which is of variable length and has a female I.V. connection at proximal end 53a. Infusion portion 70 has a smooth exterior surface 70a and may be of any geometric cross-section, including circular (FIG. 9), square (FIG. 9a), oval (FIG. 9b) or triangular (FIG. 11a) cross-section. A secondary channel 71 is formed within a thickened portion 72 of the tube wall and extends parallel to the lumen of infusion member 52 from distal end 73 into a communicating recess 75 formed in hub member protrusion 51. The cross-sectional area of secondary channel 71 is usually, but not always, less than the cross-sectional area of catheter lumen 70a whereby the magnitude of lumenal flow is at most slightly reduced. A semi-rigid metallic stylette 80 has a cross-sectional shape selected to be closely received within the bore of secondary channel 71. Thus, a first stylette 80 has an oval cross-section for use in oval cross-section secondary channel 71 formed in a portion of the wall 72 of a circular cross-section catheter 52 (FIG. 9); another catheter 52' of square cross-section (FIG. 9a) has a secondary channel 71' formed with a rectangular cross-section to closely receive a stylette 80' having a cooperative rectangular cross-section; and a third catheter 52" (FIG. 9b) has a secondary channel 71" of highly eccentric oval cross-section to closely receive a stylette 80" having a cooperative oval cross-section. The distal end 81 of stylette 80 is bevelled and sharpened to enable a venipuncture to be performed even when infusion portion 70 is formed of a flexible material. Stylette 80 is bent to allow its proximal end 82 to extend through recess 75 in a direction substantially perpendicular to the axial direction of infusion member 52 and away from the top surface 51a of protrusion 51. The length of stylette 80 is selected to allow distal end 81 to extend forward of catheter end 73 when stylette extension 82 is urged against the forward wall 75a of recess 75. The length S of recess 75 is selected to allow complete withdrawal of distal end 81 within secondary channel 71 when extension 82 is urged against the rear walls 75b of recess 75. Stylette 80 cannot be removed in normal use and remains rigidly positioned within secondary channel 71 to resist and prevent kinking and twisting movement of infusion portion 70, while distal end 81 is enclosed and protected by the forward portion 70b of the catheter whereby danger of laceration to the surrounding tissue is reduced. The width of a styletto 80 may be maximized for formation of a puncture having a size approaching the cross-sectional area of the catheter, for ease of insertion thereof. In another preferred embodiment, a styletto-catheter 90 (FIG. 10) is utilized independent of hub 10. Styletto-catheter 90 comprises a flexible tube 91 having a catheter lumen 92 generally axially formed therethrough. Tube 91 has a bevelled distal end 91a and a flared proximal end 91b adapted to force-fittingly receive a standard male intravenous coupling 93 in axial connection. A portion 94 of the catheter wall is gradually thickened to extend into lumen 92. At least one secondary channel 95 is axially formed within thickened wall portion 94. A flexible stylette member 96 is positioned within each secondary channel 95. The distal end 96a of stylette 96 is sharpened to enable formation of a venipuncture or the like, and the proximal end 96b of stylette 96 is bent to extend radially away from the axis of lumen 92. A recess 91c is formed in the wall of catheter 91 adjacent to stylette extension 96b to enable the stylette to be urged toward catheter tip 91a until stylette tip 96a protrudes therefrom for the cutting operation. The stylette is withdrawn along secondary channel 95 only until stylette extension 96b abuts a protrusion 97, to prevent complete removal of the stylette. It should be understood that the resiliency of the material utilized in the formation of catheter 91 is sufficiently high to cooperate with the exterior surface of stylette 96 to form a liquid-tight seal to prevent fluid passage along the secondary channel. Styletto-catheter 90 may utilize a single stylette 96 emplaced within a single secondary channel 95 (FIGS. 11 and 11a), or may advantageously utilize a pair of independently movable stylettes 96,96' (FIG. 11b), each independently slidably enclosed within its own secondary channel 95, 95' formed within a like number of thickened portions 94, 94' in the wall of the catheter. The shape, number and position of the stylettes are chosen for the required end use. The cross-sectional area of the thickened wall portion 94 (of 71 of FIG. 8 and 8a), and hence of stylette 80 or 96, may be selected to decrease the cross-sectional area of the lumen 92 of the catheter by an insignificant amount, or may be selected to allow use of a stylette 96 having a greater width than the width of the lumen 92, to form a large area puncture for ease of catheter insertion. Each stylette may advantageously be V-shaped (FIG. 11a) to cut a flat of skin, to even further enlarge the puncture area for ease of catheter insertion. There has just been described a novel, multi-angle U-shaped hub for an infusion member and tube, allowing the infusion tube to be maintained at one of a plurality of angular orientations with respect to the axis of the infusion member. A novel styletto-catheter having its stylette slidably received within a secondary channel formed within a wall of a single-lumen catheter is described, which styletto-catheter may be used either with the U-shaped hub or independently. The present invention has been described in connection with several preferred embodiments thereof; many variations and modifications will now become apparent to those skilled in the art. It is preferred, therefore, the present invention be limited not by the specific disclosure herein, but only by the appended claims.

A U-shaped hub has a plurality of clips formed along its exterior periphery to selectively receive an infusion tube at one of a like plurality of fixed angles relative to a protrusion extending from the periphery of the hub. The junction of the infusion tube and a hollow infusion member, such as an intravenous needle, a sheathed needle, a catheter, a cannula, a styletto-catheter or the like, is embedded within the hub projection. The channel diameter of each hub clip is substantially equal to the outer diameter of the flexible infusion tube to prevent collapse of the tube wall while enabling the initially straight tube to be bent and retained at one of a plurality of angles with respect to the center line of the infusion member to permit the use of a direct tubing connection between an intravenous source and the infusion member and for reducing the danger of lateral movement of the infusion member relative to the body. A novel styletto-catheter having a slidably retractable but non-removable stylette positioned in a separate channel within the wall of the catheter lumen is disclosed for use either with or without the U-shaped hub. The non-removable stylette prevents kinking, twisting and shape-distortion of the infusion member after the insertion thereof.

RELATED APPLICATION INFORMATION [0001] This claims priority to U.S. Patent Application No. 61/780,472, filed on Mar. 13, 2013, the entire contents of which are incorporated herein by reference. FIELD OF THE INVENTION [0002] This invention describes an improved process utilizing nitric acid and oxygen as co-oxidants to oxidize aldehydes, alcohols and/or polyols, preferably carbohydrates to produce the corresponding carboxylic acids. The improved process described herein can be used as a batch process or as a continuous process. BACKGROUND OF THE INVENTION [0003] Hydroxycarboxylic acids, and in particular carbohydrate diacids (aldaric acids) offer significant economic potential as carbon based chemical building blocks for the chemical industry, as safe additives or components of products used in pharmaceutical preparations and food products, and as structural components of biodegradable polymers, if they can be effectively produced on an industrial scale. Glucaric acid, for example, is produced through the oxidation of glucose and in salt form is currently in use as a nutraceutical for preventing cancer. The price of this material however is high, approximately $100/lb. Industrial scale production of aldaric acids would also provide sufficient materials for the production of other useful compounds, that include environmentally degradable polyamides with varying properties and applications, which are otherwise not commercially available. [0004] Carbohydrate diacids are produced a number of ways from reducing sugars using a variety of oxidizing agents, including nitric acid. An example of a nitric acid oxidation of a carbohydrate is that of D-glucose to give D-glucaric acid, typically isolated as its mono potassium salt (See, W. N. Haworth and W. G. M. Jones, J. Chem. Soc., 65-76 (1944), C. L. Mehltretter and C. E. Rist, Agric. and Food Chem., 1, 779-783 (1953) and C. L. Mehltretter, “D-Glucaric Acid”, in Methods in Carbohydrate Chemistry, R. L. Whistler, M. L. Wolfrom, Eds; Academic Press, New York, 1962, Vol. II, pp 46-48). Alternatively, D-glucaric acid can be isolated from nitric acid oxidation of D-glucose as a disodium salt (See, D. E. Kiely, A. Carter and D. P. Shrout, U.S. Pat. No. 5,599,977, Feb. 4, 1997) or as the 1,4:6,3-dilactone (See, D. E. Kiely and G. Ponder, U.S. Pat. No. 6,049,004, Apr. 11, 2000). Routes have been described showing synthesis of diacids through catalytic oxidation with oxygen over a noble metal catalyst (See, C. L. Mehltretter, U.S. Pat. No. 2,472,168, Jun. 7, 1949). An additional route of synthesis exists by use of oxoammonium salts in combination with hypophalites as the terminal oxidants. For example, Merbough and coworkers describe oxidation of D-glucose, D-mannose and D-galactose to their corresponding diacids using 4-acetylamino-2,2,4,6-tetamethyl-1-piperidinyloxy (4-AcNH-TEMPO) with hypohalites as the oxidizing medium (See, N. Merbough, J. M. Bobbitt and C. Bruckner, J. Carbohydr. Chem., 21, 66-77 (2002) and Merbouh, J M. Bobbitt, and C. Bruckner, U.S. Pat. No. 6,498,269, Dec. 24, 2002). A microbial oxidation of myo-inositol to glucuronic acid which is then oxidized enzymatically or by catalytic oxidation to glucaric acid has also been recently described (See, W. A. Schroeder, P. M. Hicks, S. McFarlan, and T. W. Abraham, U.S. Patent Application, 20040185562, Sep. 24, 2004). [0005] A variety of different processes for the oxidation of carbohydrates using nitric acid are known. For example, U.S. Pat. No. 2,380,196 (the '196 patent) describes the nitric acid oxidation of carbohydrates to dibasic acids, particularly tartaric acid. The '196 patent describes a cyclic process in which in each cycle, fresh carbohydrate and residue from a previous oxidation is oxidized with nitric acid. A catalyst, such as vanadium, manganese, iron and molybdenum, is employed to increase the yield of tartaric acid. According to the '196 patent, good yields are obtained when the molar ratio of nitric acid to glucose is 5:7.5, preferably 6:7.5. The '196 patent also describes that when mixing the ingredients, the temperature should be maintained at 20° C. or lower. Following mixing, the temperature is raised gradually or allowed to rise spontaneously to about 30° C. to 35° C. (this is the induction or heating-up stage). When the temperature reaches 30° C. to 35° C., an autocatalytic strong exothermic reaction called the “blow” sets in. The “blow” stage is maintained at a temperature of about 50° C. to 75° C., preferably 65-70° C. for anywhere from 45 to 120 minutes. The final temperature stage of the oxidation is the “fume-off” stage at which the last of the nitric acid is reacted and passed off as lower nitrogen oxides. During the “fume-off” stage, the reaction mixture is maintained at a high temperature somewhat below the boiling point of the mixture, at approximately 90° C. to 95° C. until nitrogen oxide is no longer detectable by the fumes. Oxalic and tartaric acids are recovered from the oxidized reaction mixture by direct precipitation and crystallization. [0006] U.S. Pat. No. 2,436,659 (the '659 patent) discloses an improved and economical process for the production of D-saccharic acid. Specifically, the '659 patent discloses a process that produces higher yields of D-saccharic acid in a shorter period of time, is more convenient while not employing the use of metal oxidation catalysts. According to the '659 patent, crystalline D-glucose, in anhydrous or monohydrate form, is added to a solution of nitric acid at a rate that allows control of the temperature of the reaction between 55° C. to 90° C. The mole ratio of glucose to nitric acid used in the process is 1:4. However, the '659 patent notes that a mole ratio of glucose to nitric acid of 1:3 lowers the yield of D-saccharic acid while a ratio of 1:8 increases this yield. The '659 patent also discloses that when 60 to 70 percent nitric acid is used it is preferred to use reaction temperatures of 55° C. to 70° C. and that when lower concentrations of nitric acid are employed higher reaction temperatures are preferred. When the process is performed in this manner, it is quite rapid, with maximum yields of D-saccharic acid being obtained in a one-hour period of oxidation. [0007] U.S. Pat. No. 3,242,207 (the '207 patent) discloses a continuous process for the oxidation of D-glucose with nitric acid at elevated temperatures. Specifically, the process described in the '207 patent is performed as follows: (1) to an initial reaction mixture prepared by oxidizing an aqueous solution of D-glucose with concentrated nitric acids, an aqueous D-glucose solution and concentrated nitric acid in the molecular ratio of 1:3 to 1:3.5 is simultaneously and continuously added at a temperature of about 40° C. to 70° C.; (2) continuously withdrawing from the reaction vessel an apportion of the reaction mixture corresponding to the volume of the fed-in liquids; and (3) isolating the product formed. [0008] U.S. Pat. No. 7,692,041 (the '041 patent) discloses an improved method for oxidizing water soluble compounds using nitric acid oxidation. The method involves (1) preparing an aqueous solution of an organic compound suitable for nitric acid oxidation; (2) combining, over time, employing a controlled process, in a closed reaction vessel, under positive pressure of oxygen, the aqueous solution of the organic compound and an aqueous solution of nitric acid to oxidize the organic compound to a mixture of organic acids; (3) maintaining controlled, moderate temperatures of from about 25° C. to about 50° C., controlled positive pressure of oxygen, and controlled agitation of the organic compound and nitric acid reaction mixture during the oxidation reaction; and (4) removing a portion of the nitric acid from the combined aqueous solution to give a mixture of organic acids suitable for further processing. [0009] There is a need in the art for improved oxidation process that is safe, economical and efficient for converting organic compounds into their corresponding acids. SUMMARY OF THE INVENTION [0010] In one aspect, the present invention relates to a method of synthesizing a mixture of organic acids, the method comprising the steps of: [0011] (a) combining, over time, in one or more closed reaction vessels, under a positive pressure of oxygen and with continuous mixing, an organic compound suitable for nitric acid oxidation and an aqueous solution of nitric acid to form a first reaction mixture, wherein the organic compound and the aqueous solution of nitric acid are introduced into the one or more closed reaction vessels; [0012] (b) flowing said first reaction mixture through the one or more reaction vessels while maintaining a controlled temperature of from about 5° C. to about 105° C. and controlled positive pressure of oxygen of from about 0 bar g to about 1000 bar g for a time period suitable to oxidize the organic compound to a subsequent reaction mixture comprising a mixture of organic acid products and nitrogen oxides; [0013] (c) recirculating the subsequent reaction mixture into the reaction vessel vapor space headspace; and [0014] (d) recovering nitric acid from the subsequent reaction mixture. [0015] In the above method, the one or more closed reaction vessels comprise one or more reactors. More specifically, the one or more closed reaction vessels are in series (continuous) or in parallel with one another (batch). For example, the reactor can be a continuously stirred tank reactor (CSTRs), falling film reactors or tubular type plug flow reactor almost any type reactor that mixes, controls temperature and pressure and has a liquid and gas phase (not hydraulically full). [0016] The above method can be a continuous process. Alternatively, the above method can be a batch process. [0017] In the above method, the organic compound comprises a single organic material or a mixture of organic materials suitable for nitric acid oxidation. [0018] In another aspect, the above method further comprises the step of removing a significant portion of the nitric acid from the subsequent reaction mixture. [0019] In the above method, the removal of the nitric acid is accomplished by an evaporation, distillation, nanofiltration, diffusion dialysis or alcohol or ether precipitation. [0020] The above method further comprises the step of making basic the subsequent reaction mixture from which most of the nitric acid has been removed to convert residual nitric acid to inorganic nitrate and the mixture of organic acids to a mixture of organic acid salts. [0021] In the above method, organic compound suitable for nitric acid oxidation is selected from the group consisting of monohydric alcohols, diols, polyols, aldehydes, ketones, carbohydrates, hydroxyacids, cellulose, starch and combinations thereof. For example, the carbohydrates are selected from the group consisting of monosaccharides, disaccharides, oligosaccharides, aldonic acids, aldonic acid esters, aldonic acid salts, aluronic acids, alduronic acid esters, alduronic acid salts, alditols, cyclitols, corn syrups with different dextrose equivalent values, and monosaccharides, disaccharides, oligosaccharides and polysaccharides derived from plants, microorganisms or biomass sources. [0022] In the above method, the nitrogen oxides are N 2 O 3 , N 2 O 4 , NO, NO 2 and N 2 O. [0023] In another aspect, the present invention relates to a method of synthesizing a mixture of organic acids, the method comprising the steps of: [0024] (a) combining, over time, in one or more closed reaction vessels, under a positive pressure of oxygen and with continuous stirring mixing an organic compound suitable for nitric acid oxidation and an aqueous solution of nitric acid to form a reaction mixture, wherein the organic compound and the aqueous solution of nitric acid are concurrently introduced into the one or more closed reaction vessels; [0025] (b) flowing said reaction mixture through the one or more closed reaction vessels while (i) maintaining a controlled temperature of from about 5° C. to about 105° C. in a portion of the reaction vessel, (ii) maintaining a reaction vessel headspace temperature of from about 80° C. to about −42° C.; and (iii) a controlled positive pressure of oxygen of from about 0 bar g to about 1000 bar g for a time period suitable to oxidize the organic compound to a subsequent reaction mixture comprising a mixture of organic acid products and nitrogen oxides; and [0026] (c) removing most of nitric acid from the subsequent reaction mixture to give a final reaction mixture of organic acids suitable for further processing. [0027] In the above method, the one or more closed reaction vessels comprise one or more reactors. More specifically, the one or more closed reaction vessels are in series (continuous) or in parallel with one another (batch). For example, the reactor can be a continuously stirred tank reactor (CSTRs), falling film reactor or a tubular type plug flow reactor or almost any type reactor that can mix, controls temperature and pressure and has a liquid and gas phase (not hydraulicly full). The above method can be a continuous process. Alternatively, the above method can be a batch process. [0028] In the above method, the organic compound comprises a single organic material or a mixture of organic materials suitable for nitric acid oxidation. [0029] In another aspect, the above method further comprises the step of removing a significant portion of the nitric acid from the subsequent reaction mixture. [0030] In the above method, the removal of the nitric acid is accomplished by an evaporation, distillation, nanofiltration, diffusion dialysis or alcohol or ether precipitation. [0031] The above method further comprises the step of making basic the subsequent reaction mixture from which most of the nitric acid has been removed to convert residual nitric acid to inorganic nitrate and the mixture of organic acids to a mixture of organic acid salts. [0032] In the above method, organic compound suitable for nitric acid oxidation is selected from the group consisting of monohydric alcohols, diols, polyols, aldehydes, ketones, carbohydrates, hydroxyacids, cellulose, starchand combinations thereof. For example, the carbohydrates are selected from the group consisting of monosaccharides, disaccharides, oligosaccharides, aldonic acids, aldonic acid esters, aldonic acid salts, aluronic acids, alduronic acid esters, alduronic acid salts, alditols, cyclitols, corn syrups with different dextrose equivalent values, and monosaccharides, disaccharides, oligosaccharides and polysaccharides derived from plants, microorganisms or biomass sources. [0033] In the above method, the nitrogen oxides are N 2 O 3 , N 2 O 4 , NO, NO 2 and N 2 O. DETAILED DESCRIPTION OF THE INVENTION [0034] The present invention relates to a safe, efficient and economical oxidation process for oxidizing organic compounds into their corresponding organic acid products. Specifically, this invention relates to an improved method for regenerating nitric acid in situ during the oxidation reaction while also improving the safety and quality of the final product. Effective regeneration of nitric acid reduces the amount of nitric acid required to accomplish the oxidation and allows subsequent recovery and recycling of the nitric acid thus improving the efficiency and economy of the process. However, increasing the amount of nitric acid during the reaction can also lead to run away oxidation rates and over oxidation of the organic substrate. Other patents have disclosed methods for regenerating nitric acid in situ during the oxidation process. U.S. Pat. No. 7,692,041 (the '041 patent) discloses an improved method for oxidizing water soluble compounds using nitric acid oxidation whereby a positive pressure of oxygen is introduced during the reaction to convert gaseous oxides of nitrogen (NOx), by-products from the oxidation, back to nitric acid. The process described in the '041 patent uses a sealed vessel, pressurized with oxygen to re-oxidize NOx in the headspace back to nitric acid, thereby improving reaction rates by increasing the nitric acid concentration in the liquid reaction phase. The '041 patent does not describe alternative methods of improving nitric acid regeneration or oxidation reaction rates. One skilled in the art would expect that increasing the temperature in the headspace would improve nitric acid regeneration by increasing the oxidation rate of NOx back to nitric acid. One skilled in the art would also expect that improving mass transfer of the gas phase back into the liquid phase would increase oxidation rates of the organic substrate. [0035] To better understand the effects of headspace temperature, the inventors used a reactor capable of independently heating and cooling the gas and liquid. The '041 patent does not disclose using a reactor having a separate control over headspace and liquid temperatures. Surprisingly, the inventors found that cooling, instead of heating, the headspace below the temperature of the liquid phase improved the overall rate of nitric acid regeneration. Increasing the rate of nitric acid regeneration allows the oxidation process in this invention to use less nitric acid than previously described to achieve the same degree of oxidation. [0036] Additionally, in another aspect, while trying to improve nitric acid regeneration by increasing mass transfer of the gas phase into the liquid phase by recirculating the liquid reaction mixture into the gaseous headspace the inventors surprisingly discovered that the oxidation reaction rates did not increase and in fact, the oxidation was quenched and conversion of the organic substrate into organic acid products was stopped. This surprising result may be used to control the energetic oxidation reaction, particularly in preventing over oxidation of the organic substrate once the desired level of oxidation has been reached. This is particularly effective when combined with improved nitric acid regeneration through cooling of the headspace which leads to faster oxidation rates and makes control over the degree of oxidation difficult to control. [0037] The oxidation process described herein can be performed as a batch-type process or as a continuous process. The first step of the process of the present invention involves combining an organic compound suitable for nitric acid oxidation with an aqueous solution of nitric acid to form an initial or first reaction mixture, whereby the organic compound is oxidized to form a reaction mixture of organic acids (which constitute part of the liquid phase during the reaction). It should also be noted that during the oxidation that gaseous oxides of nitrogen (gaseous oxides of nitrogen are also referred to herein as “nitrogen oxides” and include N 2 O 3 , N 2 O 4 , NO, NO 2 and N 2 O) are produced in the reaction mixture (which constitute part of the gas or gaseous phase). In one aspect, the organic compound and aqueous solution of nitric acid can be injected simultaneously or sequentially, in any order, into one or more closed reaction vessels that comprise a reaction vessel train. [0038] The organic compounds that can be used in the process of the present invention can generally be described to include monohydric alcohols, diols, polyols, aldehydes, ketones, carbohydrates, and mixtures thereof. Non-limiting examples of carbohydrates that may be used in the processes of the current invention include, but are not limited to, monosaccharides, such as the common monosaccharides D-glucose, D-mannose, D-xylose, L-arabinose, D-arabinose, D-galactose, D-arabinose, D-ribose, D-fructose; disaccharides, such as the common disaccharides maltose, sucrose, isomaltose, cellobiose and lactose; oligosaccharides, for example, maltotriose and maltotetrose; aldonic acids such as D-gluconic acid, D-ribonic acid, and D-galactonic acid; aldonic acid esters, lactones and salts that include, but are not limited to, those derived from D-gluconic acid, D-ribonic acid and D-galactonic acid; alduronic acids, for example, D-glucuronic acid and L-iduronic acid; alduronic esters, lactones and salts that include, but are not limited to, those derived from D-glucuronic acid and L-iduronic acid; alditols that include glycerol, threitol, erythritol, xylitol, D-glucitol; alditols with more than six carbon atoms; cyclitols, for example common cyclitols such as myo-inositol and scyllitol; corn syrups with different dextrose equivalent values; other aldonic acids and salts thereof, such as, glucoheptonic acids, glycerbionic acids, erythrobionic acids, threobionic acids, ribobionic acids, arabinobionic acids, xylobionic acids, lyxobionic acids, allobionic acids, altrobionic acids, glucobionic acids, mannobionic acids, gulobionic acids, idobionic acids, galactobionic acids, talobionic acids, alloheptobionic acids, altroheptobionic acids, glucoheptobionic acids, mannoheptobionic acids, guloheptobionic acids, idoheptobionic acids, galactoheptobionic acids and taloheptobionic acids; glycols such as ethylene glycol, diethylene glycols, triethylene glycols or mixtures thereof; mixtures of carbohydrates from different biomass, plant or microorganism sources; polysaccharides from biomass, plant or microorganism sources (such as starch, celluloses, etc.) and of varying structures, saccharide units and molecular weights. The organic compound may also comprise a combination of one or more of the organic compounds. The organic compound may be added neat (namely, as pure substance as a solid or liquid (namely, aqueous)), depending on the desired properties of the reaction mixture. In one aspect, the organic compound is provided as an aqueous solution. [0039] As mentioned previously herein, the organic compound is combined with an aqueous solution of nitric acid to form the initial or first reaction mixture. The concentration of nitric acid used in the process of the present invention is not critical. For example, the nitric acid used can be 60% nitric acid, 70% nitric acid, etc. It will be understood by one skilled in the art that the ratio of aqueous nitric acid to organic compound used in the process of the present invention can vary depending on the desired oxidation product composition. The molar ratio is calculated at the beginning of the reaction if all reactants are added at the beginning of the reaction in batch (all together) or in a continuous flow reactor system (all together in the first reactor of the reactor system). The molar ratio is calculated at the end of the reaction step if a fed batch is used (the phrase “fed batch” means starting with one of the reactants (such as an organic compound or nitric acid) in a reaction vessel and then adding the other reactants as the reaction progresses to completion) or if a continuous series of reaction vessels are used and one of the reactants is added at different locations through the reactor train (an amount is added to each reactor vessel in the reactor train). In one aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.1:1 to approximately 2:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.25:1 to approximately 1.8:1. In still yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.25:1 to approximately 1.7:1. In still yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.25:1 to approximately 1.6:1. In still yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.25:1 to approximately 1.5:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.25:1 to approximately 1.4:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.25:1 to approximately 1.3:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.25:1 to approximately 1.2:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.25:1 to approximately 1:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.25:1 to approximately 0.9:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.25:1 to approximately 0.8:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.25:1 to approximately 0.75:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.25:1 to approximately 0.65:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.4:1 to approximately 1.8:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.4:1 to approximately 1.7:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.4:1 to approximately 1.6:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.4:1 to approximately 1.5:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.4:1 to approximately 1.4:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.4:1 to approximately 1.3:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.4:1 to approximately 1.2:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.4:1 to approximately 1:1. In another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.4:1 to approximately 0.9:1. In another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.4:1 to approximately 0.8:1. In another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.4:1 to approximately 0.75:1. In another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.4:1 to approximately 0.65:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.5:1 to approximately 1.8:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.5:1 to approximately 1.7:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.5:1 to approximately 1.6:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.5:1 to approximately 1.5:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.5:1 to approximately 1.4:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.5:1 to approximately 1.3:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.5:1 to approximately 1.2:1. In yet another aspect, the molar ratio of aqueous nitric acid to organic compound ranges from approximately 0.5:1 to approximately 1:1. In another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.5:1 to approximately 0.9:1. In another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.5:1 to approximately 0.8:1. In another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.5:1 to approximately 0.75:1. In another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.5:1 to approximately 0.65:1. In another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.5:1 to approximately 0.65:1. In a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.5:1. In a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.6:1. In a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.7:1. In a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.8:1. In a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.9:1. In yet a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.1:2. In still yet a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.1:1.5. In still yet a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.1:1. In yet a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.25:3. In still yet a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.25:1.5. In still yet a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.25:1. In yet a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.50:2. In still yet a further aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 0.50:1.5. In still yet another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 1.5:1. In still yet another aspect, the molar ratio of aqueous nitric acid to organic compound is approximately 2:1. [0040] Optionally, inorganic nitrate can be added into the reaction mixture at any time during the oxidation process. Generally, the inorganic nitrite will be added at the beginning during the period of time that the first reaction mixture is being formed. Generally, once the oxidation reaction has begun, it may no longer be necessary to add any additional nitrate. [0041] The initial reaction mixture is prepared (in one or more reaction vessels) at a temperature that generally ranges from about 5° C. to about 105° C. For example, the temperature ranges may be from about 10° C. to about 105° C., about 15° C. to about 105° C., about 20° C. to about 105° C., about 25° C. to about 105° C., about 30° C. to about 105° C., about 35° C. to about 105° C., about 40° C. to about 105° C., about 45° C. to about 105° C., about 50° C. to about 105° C., about 55° C. to about 105° C., about 60° C. to about 105° C., about 5° C. to about 100° C., about 10° C. to about 100° C., about 15° C. to about 100° C., about 20° C. to about 100° C., about 25° C. to about 100° C., about 30° C. to about 100° C., about 35° C. to about 100° C., about 40° C. to about 100° C., about 45° C. to about 100° C., about 50° C. to about 100° C., about 55° C. to about 100° C., about 60° C. to about 100° C., about 5° C. to about 95° C., about 10° C. to about 95° C., about 15° C. to about 95° C., about 20° C. to about 95° C., about 25° C. to about 95° C., about 30° C. to about 95° C., about 35° C. to about 95° C., about 40° C. to about 95° C., about 45° C. to about 95° C., about 50° C. to about 95° C., about 55° C. to about 95° C., about 60° C. to about 95° C., about 5° C. to about 90° C., about 10° C. to about 90° C., about 15° C. to about 90° C., about 20° C. to about 90° C., about 25° C. to about 90° C., about 30° C. to about 90° C., about 35° C. to about 90° C., about 40° C. to about 90° C., about 45° C. to about 90° C., about 50° C. to about 90° C., about 55° C. to about 90° C., about 60° C. to about 90° C., about 5° C. to about 85° C., about 10° C. to about 85° C., about 15° C. to about 85° C., about 20° C. to about 85° C., about 25° C. to about 85° C., about 30° C. to about 85° C., about 35° C. to about 85° C., about 40° C. to about 85° C., about 45° C. to about 85° C., about 50° C. to about 85° C., about 55° C. to about 85° C., about 60° C. to about 85° C., about 5° C. to about 80° C., about 10° C. to about 80° C., about 15° C. to about 80° C., about 20° C. to about 80° C., about 25° C. to about 80° C., about 30° C. to about 80° C., about 35° C. to about 80° C., about 40° C. to about 80° C., about 45° C. to about 80° C., about 50° C. to about 80° C., about 55° C. to about 80° C., about 60° C. to about 80° C., about 5° C. to about 70° C., about 10° C. to about 70° C., about 15° C. to about 70° C., about 20° C. to about 70° C., about 25° C. to about 70° C., about 30° C. to about 70° C., about 35° C. to about 70° C., about 40° C. to about 70° C., about 45° C. to about 70° C., about 50° C. to about 70° C., about 55° C. to about 70° C., about 60° C. to about 70° C., about 55° C. to about 105° C., about 60° C. to about 105° C., about 65° C. to about 105° C., about 70° C. to about 105° C., about 75° C. to about 105° C., about 80° C. to about 105° C., about 85° C. to about 105° C., about 90° C. to about 105° C., about 55° C. to about 100° C., about 60° C. to about 100° C., about 65° C. to about 100° C., about 70° C. to about 100° C., about 75° C. to about 100° C., about 80° C. to about 100° C., about 85° C. to about 100° C., about 90° C. to about 100° C., about 55° C. to about 95° C., about 60° C. to about 95° C., about 65° C. to about 95° C., about 70° C. to about 95° C., about 75° C. to about 95° C., about 80° C. to about 95° C., about 85° C. to about 95° C., about 90° C. to about 95° C., about 55° C. to about 90° C., about 60° C. to about 90° C., about 65° C. to about 90° C., about 70° C. to about 90° C., about 75° C. to about 90° C., about 80° C. to about 90° C., about 85° C. to about 90° C., about 25° C. to about 55° C., or about 25° C. to about 50° C. [0042] As mentioned previously, the reaction mixture is contained within one or more closed reaction vessels that are capable of carrying out the oxidation process. For example, any type of reaction vessel that allows for the gas and liquid phases to have a high mass transfer during the oxidation reaction can be used. In one aspect, the reactor is capable of independently heating and cooling the gas and liquid phases. Examples of reactor vessels that can be used include one or more continuously stirred tank reactors (CSTRs), plug flow reactors, spinning disc reactors, or tubular type plug flow reactors. Additionally, the reaction vessel can contain heat transfer systems such as coils, jackets, loops, etc. Furthermore, when one or more reaction vessels are used, any combination of different types and kinds of reaction vessels can be use. For example, the reaction train can contain a combination of one or more CSTRs, one or more tubular type plug flow reactors, and/or one or more evaporators. The reaction train contain one reaction vessel, two reaction vessels, three reaction vessels, four reaction vessels, five reaction vessels, six reaction vessels, seven reaction vessels, eight reaction vessels, nine reaction vessels or ten reaction vessels. If one or more reaction vessels are used, the reaction vessels can be connected in series with one another or one (such as in a continuous process) or one or more reaction vessels can be used in parallel (such as in a batch process). [0043] The reaction vessel can be described as a container or vessel that is insulated from the external environment, such that the reaction mixture contained within the tank reactor is not exposed to ambient air. Additionally, the reaction vessel can comprise one or more mixing elements that are capable of continuously stirring and providing controlled agitation of the reaction mixture within the vessel. The one or more mixing elements may include, but are not limited to magnetic stirrers, propeller stirrers, turbine stirrers, anchor stirrers, kneading stirrers, centrifugal stirrers, paddle stirrers and combinations thereof. Generally, the mixing element is electronically controlled such that the spinning velocity of the mixing element may be altered as needed. [0044] The reaction vessel typically maintains a vapor or head space wherein the gaseous phase (gaseous oxides of nitrogen) exists in addition to the liquid phase. The vapor or head space is created by filing the tank reactor with a volume of the reaction mixture that is less than 100% of the volume of the tank. Generally, the reaction vessel is filled with a volume that ranges from approximately 1% of the reaction vessel volume to approximately 99% of the reaction vessel volume. In certain aspects of the current invention, the reaction mixture comprises a volume of the reaction vessel that is not greater than 95%, not greater than 90%, not greater than 85%, not greater than 80%, not greater than 75%, not greater than 70%, not greater than 65%, not greater than 60%, not greater than 55%, not greater than 50%, not greater than 45%, not greater than 40%, not greater than 35%, not greater than 30%, not greater than 25%, not greater than 20%, not greater than 15%, not greater than 10%, and not greater than 5%. [0045] In one aspect, the vapor or head space of one or more reaction vessels may be maintained at a temperature of from about 80° C. to about −42° C. For example, the temperature of the vapor (gas phase) or head space can be from about 80° C. to about −41° C., about 80° C. to about −40° C., about 80° C. to about −35° C., about 80° C. to about −30° C., about 80° C. to about −20° C., about 80° C. to about −15° C., about 80° C. to about −10° C., about 70° C. to about −42° C., about 70° C. to about −41° C., about 70° C. to about −40° C., about 70° C. to about −35° C., about 70° C. to about −30° C., about 70° C. to about −20° C., about 70° C. to about −15° C., about 70° C. to about −10° C., about 60° C. to about −42° C., about 60° C. to about −41° C., about 60° C. to about −40° C., about 60° C. to about −35° C., about 60° C. to about −30° C., about 60° C. to about −20° C., about 60° C. to about −15° C., about 60° C. to about −10° C., about 50° C. to about −42° C., about 50° C. to about −41° C., about 50° C. to about −40° C., about 50° C. to about −35° C., about 50° C. to about −30° C., about 50° C. to about −20° C., about 50° C. to about −15° C., about 50° C. to about −10° C., 40° C. to about −42° C., about 40° C. to about −41° C., about 40° C. to about −40° C., about 40° C. to about −35° C., about 40° C. to about −30° C., about 40° C. to about −20° C., about 40° C. to about −15° C., about 40° C. to about −10° C., about 30° C. to about −42° C., about 30° C. to about −41° C., about 30° C. to about −40° C., about 30° C. to about −35° C., about 30° C. to about −30° C., about 30° C. to about −20° C., about 30° C. to about −15° C., about 30° C. to about −10° C., about 20° C. to about −42° C., about 20° C. to about −41° C., about 20° C. to about −40° C., about 20° C. to about −35° C., about 20° C. to about −30° C., about 20° C. to about −20° C., about 20° C. to about −15° C., about 20° C. to about −10° C., about 10° C. to about −42° C., about 10° C. to about −41° C., about 10° C. to about −40° C., about 10° C. to about −35° C., about 10° C. to about −30° C., about 10° C. to about −20° C., about 10° C. to about −15° C., about 10° C. to about −10° C., about 5° C. to about −42° C., about 5° C. to about −41° C., about 5° C. to about −40° C., about 5° C. to about −35° C., about 5° C. to about −30° C., about 5° C. to about −20° C., about 5° C. to about −15° C. or about 5° C. to about −10° C. While the vapor or head space of one or more reaction vessels may be maintained at a temperature of from about 80° C. to about −42° C., the liquid phase of the one or more reaction vessels may be maintained at a temperature of 5° C. to about 105° C. In one aspect, the vapor or head space is maintained at a lower temperature than the temperature of the liquid phase in the reaction vessel. For example, the vapor or head space is at least 1° C., 5° C., 10° C., 15° C., 20° C., 25° C., 30° C., 35° C., 40° C., 45° C., 50° C., 55° C., 60° C., 65° C., 70° C., 75° C., 80° C., 85° C., 90° C., 95° C. or 100° C. cooler than the liquid phase. [0046] By specifically controlling the head space to temperature and pressure, the inventors of the present invention found that this results in an improvement in the rate of conversion of nitrogen oxides to nitric acid in the vapor space. Specifically, the inventors found that cooling the headspace below the temperature of the liquid phase improved the overall rate of nitric acid regeneration. Increasing the rate of nitric acid regeneration allows the oxidation process in this invention to use less nitric acid than previously described to achieve the same degree of oxidation. In addition, the process of the present invention is more economical because less nitric acid is lost during pressure control venting of the reaction and during the recovery steps of the process discussed later herein. In other words, the method of the present invention results in a “low waste” oxidation process which has not existed previously. As used herein, the term “low waste” means that less than 1%, less than 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than 0.1% of nitric acid is lost during the process of the present invention during pressure control venting of the reaction and during the recovery steps. [0047] The process of the present invention requires exposing the first reaction mixture to the positive pressure of oxygen. Therefore, oxygen is added at point at time and at some location in the one or more reaction vessels. The addition of oxygen and the location of its addition may be during the formation of the initial or first reaction mixture. Alternatively, in another aspect, oxygen can be added in the last reactor or only reactor (if only a single reactor comprises the reaction train). Still further alternatively, oxygen may be added at a selected reactor in the reaction vessel train. Still further alternatively, oxygen can be to each individual reaction vessel comprising the reaction vessel train. The oxygen may be introduced into the first reaction mixture by any means known in the art, including bubbling gaseous oxygen through the reaction mixture. The oxygen added to the reaction vessel train can be added cocurrently or countercurrently or both cocurrently and countercurrently. The pressure within the reaction vessel generally ranges from above about 0 bar g to about 1000 bar g. In one aspect, the pressure can range from about 1 bar g to about 1000 bar g, about 5 bar g to about 1000 bar g, about 10 bar g to about 1000 bar g, 20 bar g to about 1000 bar g, about 30 bar g to about 1000 bar g, about 40 bar g to about 1000 bar g, 50 bar g to about 1000 bar g, about 60 bar g to about 1000 bar g, about 70 bar g to about 1000 bar g, about 80 bar g to about 1000 bar g, about 90 bar g to about 1000 bar g, about 100 bar g to about 1000 bar g, about 200 bar g to about 1000 bar g, about 300 bar g to about 1000 bar g, about 400 bar g to about 1000 bar g, about 50 bar g to about 1000 bar g, 0 bar g to about 900 bar g, 1 bar g to about 900 bar g, about 5 bar g to about 900 bar g, about 10 bar g to about 900 bar g, 20 bar g to about 900 bar g, about 30 bar g to about 900 bar g, about 40 bar g to about 900 bar g, 50 bar g to about 900 bar g, about 60 bar g to about 900 bar g, about 70 bar g to about 900 bar g, about 80 bar g to about 900 bar g, about 90 bar g to about 900 bar g, about 100 bar g to about 900 bar g, about 200 bar g to about 900 bar g, about 300 bar g to about 900 bar g, about 400 bar g to about 900 bar g, about 50 bar g to about 900 bar g, 0 bar g to about 800 bar g, 1 bar g to about 800 bar g, about 5 bar g to about 800 bar g, about 10 bar g to about 800 bar g, 20 bar g to about 800 bar g, about 30 bar g to about 800 bar g, about 40 bar g to about 800 bar g, 50 bar g to about 800 bar g, about 60 bar g to about 800 bar g, about 70 bar g to about 800 bar g, about 80 bar g to about 800 bar g, about 90 bar g to about 800 bar g, about 100 bar g to about 800 bar g, about 200 bar g to about 800 bar g, about 300 bar g to about 800 bar g, about 400 bar g to about 800 bar g, about 50 bar g to about 800 bar g, 0 bar g to about 700 bar g, 1 bar g to about 700 bar g, about 5 bar g to about 700 bar g, about 10 bar g to about 700 bar g, 20 bar g to about 700 bar g, about 30 bar g to about 700 bar g, about 40 bar g to about 700 bar g, 50 bar g to about 700 bar g, about 60 bar g to about 700 bar g, about 70 bar g to about 700 bar g, about 80 bar g to about 700 bar g, about 90 bar g to about 700 bar g, about 100 bar g to about 700 bar g, about 200 bar g to about 700 bar g, about 300 bar g to about 700 bar g, about 400 bar g to about 700 bar g, about 50 bar g to about 700 bar g, 0 bar g to about 600 bar g, 1 bar g to about 600 bar g, about 5 bar g to about 600 bar g, about 10 bar g to about 600 bar g, 20 bar g to about 600 bar g, about 30 bar g to about 600 bar g, about 40 bar g to about 600 bar g, 50 bar g to about 600 bar g, about 60 bar g to about 600 bar g, about 70 bar g to about 600 bar g, about 80 bar g to about 600 bar g, about 90 bar g to about 600 bar g, about 100 bar g to about 600 bar g, about 200 bar g to about 600 bar g, about 300 bar g to about 600 bar g, about 400 bar g to about 600 bar g or about 50 bar g to about 600 bar g. In still another aspect, the pressure can range from about 1 bar g to about 200 bar g, about 5 bar g to about 200 bar g, about 10 bar g to about 200 bar g, about 20 bar g to about 200 bar g, about 30 bar g to about 200 bar g, about 40 bar g to about 200 bar g, about 50 bar g to about 200 bar g, 1 bar g to about 100 bar g, about 5 bar g to about 100 bar g, about 10 bar g to about 100 bar g, about 20 bar g to about 100 bar g, about 30 bar g to about 100 bar g, about 40 bar g to about 100 bar g, about 50 bar g to about 100 bar g, 1 bar g to about 50 bar g, about 5 bar g to about 50 bar g, about 10 bar g to about 50 bar g, about 20 bar g to about 50 bar g, about 30 bar g to about 50 bar g, or about 40 bar g to about 50 bar g. [0048] The first reaction mixture flows through the one or more reaction vessels or reaction vessel train under the controlled temperature and controlled positive pressure of oxygen as described previously herein (namely, a controlled temperature of from about 5° C. to about 105° C. and a controlled positive pressure of oxygen from about 0 bar g to about 1000 bar g) for a period of time suitable to oxidize the organic compounds in the first reaction mixture to form a subsequent (or second) reaction mixture that comprises a mixture of organic acid products and nitrogen oxides (namely, N 2 O 3 , N 2 O 4 , NO, NO 2 and N 2 O). [0049] Once this subsequent (final) reaction mixture is formed, it is contacted with, delivered or recirculated to the vapor or headspace of one or more reaction vessels. If multiple reaction vessels are used, the subsequent (final) reaction mixture can be contacted, delivered or recirculated in any of the reaction vessels that contain the subsequent (final) reaction mixture. For example, recirculation may occur in the last or second to last reaction vessel comprising the reaction train. [0050] The step of contacting, delivering or recirculating is important in the process of the present invention. Specifically, the contacting, delivery or recirculation step is used convert or recycle the nitrogen oxides contained in the subsequent (final) reaction mixture and gases back to nitric acid (HNO 3 ). This “converted” or “recycled” nitric acid can be reused in the oxidation process through methods described herein. [0051] The contacting, delivering or recirculating can be conducted using any technique known in the art provided that a means is used that provides for a high surface area of contact between the gas and liquid phases contained in the subsequent final reaction mixture thereby allowing the nitrogen oxides to be converted or recycled back to nitric acid. The most important aspect is that some means is used to increase the surface area. Basically, any means for creating a high surface area of contact between the gas and liquid phases contained in a reaction vessel can be used in the process of the present invention. For example, the reaction vessel can comprise a pump at the bottom and a spray nozzle at the top. The pump transports the subsequent (final) reaction mixture to the top of the reaction vessel to one or more spray nozzles which spray the reaction mixture into the reaction vessel thereby creating a high surface area of contact. Alternatively, a falling film contactor or packed bed (such as a random, structured, or anything that can cause high surface area contact as known by those skilled in the art), where liquid is pumped from the bottom to the top of a device that creates high surface area as the liquid drops through the tubes of a heat exchanger or a high surface area bed can be used. Alternatively, a high surface area of contact between the gas and liquid phases contained in the subsequent (final) reaction mixture can be created by employing an agitator which can be used to create a high rate of agitation (either horizontal or vertical) in one or more reaction vessels thereby resulting in the reaction mixture being thrown or pushed into the vapor space above the liquid. High rates of agitation using an agitator in one or more reaction vessels employed in the process of the present invention can be determined using routine techniques known to those skilled in the art. [0052] While conducting an experiment to understand if improving the mass transfer between the gas and liquid phases the reaction would speed up the reaction, the inventors surprisingly the inventors surprisingly discovered that the oxidation reaction rates did not increase and in fact, the oxidation was quenched and conversion of the organic substrate into organic acid products was stopped. Specifically, the inventors found that when the subsequent (final) reaction mixture was sprayed from one or more spray nozzles at the top of the reaction vessel during this contacting, delivering or recirculating step, that the oxidation reaction immediately terminated, which was immediately identified/recognized by reduced cooling load and the colors of the NOX gas and liquids changing from dark to clear relatively quickly. This surprising result may be used to control the energetic oxidation reaction, particularly in preventing over oxidation of the organic substrate once the desired level of oxidation has been reached. This is particularly effective when combined with improved nitric acid regeneration (discussed more in the next paragraph below) through cooling of the headspace which leads to faster oxidation rates and makes control over the degree of oxidation difficult to control. [0053] Additionally, the inventors also discovered that the contacting, delivering or recirculating step allowed for the more efficient recovery of nitric acid as the nitric compounds were more quickly converted to nitric acid due to the efficient contact of the vapor and liquid The inventors believe that the reason the reaction is terminated with this step is that the nitrogen oxides contained in both the headspace and the subsequent (final) reaction mixture are converted back to nitric acid. Once the contacting, delivering or recirculating (recirculation) step is completed and the nitrogen oxides converted to nitric acid, then the nitric acid can be recovered or removed from the subsequent (final) reaction mixture to give a final reaction mixture of organic acids that are suitable for further processing. The nitric acid can be recovered or removed from the subsequent reaction mixture using any technique known in the art. For example, evaporation, distillation, nanofiltration, diffusion dialysis or alcohol or ether precipitation can be used. Regardless of the technique used, a significant portion of the nitric acid is removed from the subsequent (final) reaction mixture. In one aspect, the term “significant” when used in connection with removal of nitric acid from the subsequent (final) reaction mixture means that at least 65% of the nitric acid is removed from the subsequent (final) reaction mixture. In another aspect, the term “significant” when used in connection with removal of nitric acid from the subsequent (final) reaction mixture means that at least 70% of the nitric acid is removed from the subsequent (final) reaction mixture. In still yet another aspect, the term “significant” when used in connection with removal of nitric acid from the subsequent (final) reaction mixture means that at least 75% of the nitric acid is removed from the subsequent (final) reaction mixture. In still yet another aspect, the term “significant” when used in connection with removal of nitric acid from the subsequent (final) reaction mixture means that at least 80% of the nitric acid is removed from the subsequent (final) reaction mixture. In another aspect, the term “significant” when used in connection with removal of nitric acid from the subsequent (final) reaction mixture means that at least 85% of the nitric acid is removed from the subsequent (final) reaction mixture. In another aspect, the term “significant” when used in connection with removal of nitric acid from the subsequent (final) reaction mixture means that at least 90% of the nitric acid is removed from the subsequent (final) reaction mixture. In another aspect, the term “significant” when used in connection with removal of nitric acid from the subsequent (final) reaction mixture means that at least 95% of the nitric acid is removed from the subsequent (final) reaction mixture. In another aspect, the term “significant” when used in connection with removal of nitric acid from the subsequent (final) reaction mixture means that at least 99% of the nitric acid is removed from the subsequent (final) reaction mixture. In another aspect, the term “significant” when used in connection with removal of nitric acid from the subsequent (final) reaction mixture means that 99.9% of the nitric acid is removed from the subsequent (final) reaction mixture. For example if the nitric acid is to be removed by evaporation, any evaporator known in the art can be used. Examples of evaporators that can be used in the process of the present invention include, but are not limited to, vertical-pipe, horizontal-pipe, slanting-pipe, rotor or thin-layer, centrifugal, worm and falling-film evaporators, tube-bundle evaporators, basket evaporators, high viscosity evaporators, evaporators with one or more scrubbers, evaporators with one or more boilers, evaporators with one or more distillation columns, evaporators with external return pipe and forced circulation, evaporators with external heating elements and forced circulation and other evaporators known to those skilled in the art. In one aspect, the method of evaporation comprises the use of at least one wiped film evaporator. In an alternative aspect, the method of evaporation comprises the use of at least two wiped film evaporators. In yet another aspect, the method of evaporation comprises the use of a wiped film evaporator and another type of evaporator such as a vertical-pipe evaporator, a horizontal-pipe evaporator, a basket evaporator, etc. In one aspect, more than one evaporator is used in the reaction train. In one aspect, more than two evaporators are used in the reaction train. In another aspect, more than three evaporators are used in the reaction train. In yet another aspect, more than four evaporators are used in the reaction train. In still another aspect, more than one evaporator is used in the reaction train in which at least one evaporator contains a scrubber, condenser or a distillation column. In still another aspect, more than two evaporators are used in the reaction train in which at least one evaporator contains a scrubber, condenser or a distillation column. In still another aspect, more than three evaporators are used in the reaction train in which at least one evaporator contains a scrubber, condenser or a distillation column. In still another aspect, more than four evaporators are used in the reaction train in which at least one evaporator contains a scrubber, condenser or a distillation column. [0054] Alternatively, as mentioned previously, the nitric acid can be removed from the subsequent (final) reaction mixture using diffusion dialysis. Diffusion dialysis can be used to remove nitric acid from the reaction mixture instead of or in conjunction with an evaporator. This process is typically used for the separation of common inorganic acids such as hydrochloric acid, sulfuric acid, or nitric acid from multivalent metal cations such as Cu 2+ or Zn 2+ . The aqueous acid feedstock of the inorganic acid and metal salt(s) and a separate water stream are routed through a diffusion dialysis system consisting of low pressure pumps and an appropriate membrane system. Two aqueous exit streams are generated, an acid recovery stream comprised primarily of inorganic acid with some metal salt(s), and a product recovery stream comprised of primarily metal salt(s) with some inorganic acid. The separate streams can be subjected to further diffusion dialysis as needed to give a stream with higher inorganic acid concentration and lower metal salt concentrations, and a stream with higher metal salt concentration and lower inorganic acid concentration. This separation technique was applied to nitric acid oxidation reaction mixtures as prepared by the described methods herein, and was found to perform in the same manner as used in separation of inorganic acids from metal salts. The bulk of the nitric acid with some organic acid products, was in the acid recovery stream, and the bulk of the organic acid products with some of the nitric acid, was in the organic product recovery stream. The use of this technology to separate nitric acid from the organic acid products produced from the oxidation process described here is a very low energy process, operates at ambient temperature, and can be run continuously. It offers an additional advantage over direct evaporation/distillation of nitric acid from the reaction mixture in that in the latter process, additional oxidative processes can occur generating additional nitrogen oxide gases that have to be contained, removed and/or converted to oxides of nitrogen that are convertible to nitric acid. In contrast, the diffusion dialysis process operates at dilute concentrations and the recovered nitric acid stream from the diffusion dialysis process is low in carbohydrate product content and evaporation/distillation of the recovered nitric acid is achieved with minimal oxidation and nitrogen oxide formation occurring during nitric acid recovery. [0055] It is recognized that the final reaction mixture from which nitric acid has been removed may be made basic to convert any residual or remaining nitric acid to inorganic nitrate, and converting the organic acids to a mixture of organic acid salts. Neutralization to a pH greater than 7 with inorganic base, without removal of nitric acid, requires base for all of the nitric acid plus the organic acids and the nitric acid is not directly recovered for further use. In contrast, partial recovery of the nitric acid for reuse by vacuum distillation is advantageous because the recovered nitric acid can be used again for oxidation purposes, although it is difficult to remove all the residual nitric acid from the syrupy concentrate with ease. [0056] Depending upon the starting organic compounds, the specific reaction conditions employed, and the target products, this solution can be treated accordingly to give the organic acids in one or more forms. Organic acids can be obtained in free acid forms, as disalts, mono salts, acid lactones, and/or dilactones, or as mixtures of various salt forms, and/or acid and/or acid lactone forms. Acids generated from oligosaccharides and other higher molecular weight carbohydrates are mixtures which can contain some of the above aldonic and aldaric acids plus higher molecular weight acids derived from higher molecular weight carbohydrates. These acids can be also be obtained in various acid, lactone and salt forms. [0057] Additionally, when oxidation products are obtained from direct concentration of the reaction mixture that removes most of the nitric acid, or by subjecting the oxidation reaction mixture to diffusion dialysis followed by removal of the bulk of the remaining nitric acid by an evaporation/distillation step, residual nitric acid can be removed as nitrate and recovered by a membrane filtration method. When the resultant syrupy product/residual nitric acid mixture is treated with an inorganic base to a pH greater than 7 , the resulting solution contains inorganic nitrate and the salt(s) of the product organic acids. This solution is then subjected to filtration, typically nanofiltration, with the bulk of inorganic nitrate passing through the membrane and into the permeate, and the bulk of the organic product remaining in the retentate. The prior art has reported removal of inorganic nitrate from organic acid salts after nitric acid oxidation using ion retardation chromatography (See, D. E. Kiely and G. Ponder, U.S. Pat. No. 6,049,004, Apr. 11, 2000). However, ion retardation chromatography is not as fast, not as applicable on a large scale, and not as efficient as the filtration methods described herein. In the oxidation processes of the current invention, the remaining retentate contains the organic acid salt forms with minimal inorganic salt content. The presence of only small amounts of inorganic nitrate in the organic acid salt products renders purification and/or isolation of the organic acid salt products or non-salt products greatly improved over previously reported methods. [0058] In an alternative aspect, the current invention also comprises a mixture of one or more organic acids, produced by the oxidation methods described herein. The mixture of one or more organic acids may be the result of the oxidation of a variety of organic compounds. The mixture of one or more organic acids generally includes the oxidation products of monohydric alcohols, diols, polyols, aldehydes, ketones, carbohydrates, and mixtures thereof. Non-limiting examples of carbohydrates suitable for oxidation by the processes of the current invention include, but are not limited to, monosaccharides, such as the common monosaccharides D-glucose, D-mannose, D-xylose, L-arabinose, D-arabinose, D-galactose, D-arabinose, D-ribose, D-fructose; disaccharides, such as the common disaccharides maltose, sucrose, isomaltose, and lactose; oligosaccharides, for example, maltotriose and maltotetrose; aldonic acids such as D-gluconic acid, D-ribonic acid, and D-galactonic acid; glucoheptonic acid; aldonic acid esters, lactones and salts that include but are not limited to those derived from D-gluconic acid, D-ribonic acid, glucoheptonic acid, and D-galactonic acid; alduronic acids, for example, D-glucuronic acid and L-iduronic acid; alduronic esters, lactones and salts that include but are not limited to those derived from D-glucuronic acid and L-iduronic acid; alditols that include glycerol, threitol, erythritol, xylitol, D-glucitol; alditols with more than six carbon atoms; cyclitols, for example common cyclitols such as myo-inositol and scyllitol; corn syrups with different dextrose equivalent values; other aldonic acids and salts thereof, such as, glucoheptonic acids, glycerbionic acids, erythrobionic acids, threobionic acids, ribobionic acids, arabinobionic acids, xylobionic acids, lyxobionic acids, allobionic acids, altrobionic acids, glucobionic acids, mannobionic acids, gulobionic acids, idobionic acids, galactobionic acids, talobionic acids, alloheptobionic acids, altroheptobionic acids, glucoheptobionic acids, mannoheptobionic acids, guloheptobionic acids, idoheptobionic acids, galactoheptobionic acids and taloheptobionic acids; glycols such as ethylene glycol, diethylene glycols, triethylene glycols or mixtures thereof; mixtures of carbohydrates from different biomass, plant or microorganism sources; polysaccharides from biomass, plant or microorganism sources (such as starch or celluloses) and of varying structures, saccharide units and molecular weights. [0059] Additionally, the mixture of one or more organic acids may include the acid or salt forms of the oxidized organic compound. Suitable examples of organic acid salts include, but are not limited to sodium hydrogen glucarate, potassium hydrogen glucarate, lithium hydrogen glucarate, disodium glucarate, sodium potassium glucarate, dipotassium glucarate, dilithium glucarate, lithium sodium glucarate, lithium potassium glucarate, zinc glucarate, calcium glucarate, sodium hydrogen xylarate, potassium hydrogen xylarate, lithium hydrogen xylarate, disodium xylarate, sodium potassium xylarate, dipotassium xylarate, dilithium xylarate, lithium sodium xylarate, lithium potassium xylarate, zinc xylarate, calcium xylarate, sodium gluconate, potassium gluconate, lithium gluconate, disodium gluconate, sodium potassium gluconate, dipotassium gluconate, dilithium gluconate, lithium sodium gluconate, lithium potassium gluconate, zinc gluconate, calcium gluconate, sodium galactarate, potassium galactarate, lithium galactarate, disodium galactarate, sodium potassium galactarate, dipotassium galactarate, dilithium galactarate, lithium sodium galactarate, lithium potassium galactarate, zinc galactarate, calcium galactarate, sodium hydrogen tartarate, potassium tartarate, lithium hydrogen tartarate, disodium tartarate, sodium potassium tartarate, dipotassium tartarate, dilithium tartarate, lithium sodium tartarate, lithium potassium tartarate, zinc tartarate, sodium hydrogen tartronate, potassium hydrogen tartronate, lithium hydrogen tartronate, disodium tartronate, sodium potassium tartronate, dipotassium tartronate, dilithium tartronate, lithium sodium tartronate, lithium potassium tartronate, zinc tartronate, calcium tartronate, sodium hydrogen oxalate, potassium hydrogen oxalate, lithium hydrogen oxalate, disodium oxalate, sodium potassium oxalate, dipotassium oxalate, dilithium oxalate, lithium sodium oxalate, lithium potassium oxalate, zinc oxalate, calcium oxalate, sodium glycolate, potassium glycolate, lithium glycolate, disodium glycolate, sodium potassium glycolate, dipotassium glycolate, dilithium glycolate, lithium sodium glycolate, lithium potassium glycolate, zinc glycolate, calcium glycolate, sodium glycerate, potassium glycerate, lithium glycerate, zinc glycerate, calcium glycerate, and combinations thereof. In another aspect, the hydroxycarboxylic acid may include, but is not limited to, disodium glucarate, sodium potassium glucarate, dipotassium glucarate, zinc glucarate, disodium xylarate, sodium potassium xylarate, dipotassium xylarate, zinc xylarate, disodium galactarate, sodium potassium galactarate, dipotassium galactarate, zinc galactarate, and combinations thereof. EXAMPLES Example 1 General Methods for High Surface Area Contact for Examples 2-4 [0060] Oxidations were carried out in a Metler Toledo Labmax reactor which is designed to operate under computer control. The Labmax was fitted with an overhead agitation motor that drove a stir shaft fitted with an anchor style agitation paddle. The reactor was made of glass and had a silicon oil filled jacket for cooling and heating. In addition, the Labmax was fitted with an overhead balance in communication with a metering pump for controlled dosing of reactants into the reactor, and resistance temperature detector (“RTD”) temperature probes to measure the temperature of both the reactor contents and the reactor jacket oil. A Mettler Toledo LMPress 60 with a pressure transducer and internal proportional-integral derivative (“PID”) loop processing was used to maintain oxygen pressure of 1.0 barg +/−0.04 barg within the reactor. A pressure manifold fitted with a pressure relief valve, a rupture disc, and a pressure gauge was added to the head of the reactor. The Labmax was controlled using iControlLabmax software version 4.0 which allows the user to specify reaction parameters, measures and logs data, and uses PID loop processing to maintain stable material temperatures during a reaction and dose reactants into the reactor at a given rate. Example 2 “Static Oxidation” [0061] A 62.5% (wt/wt) D-glucose solution was prepared by adding solid anhydrous D-glucose to deionized water in a screw-capped flask containing a stir bar. Next, the solution was heated to 65° C. with stirring. Once the glucose was adequately dissolved, the solution was cooled to 40° C. 411 g (4.5 moles) of concentrated nitric acid was then added to the reactor and the iControl software was used to maintain a reaction temperature of 25° C. and an agitation speed of 200 RPM for the duration of the reaction Immediately after the nitric acid was added 0.31 g (4.5 millimoles) of sodium nitrite was added to the reactor and the reactor was sealed and pressurized with 1 barg oxygen. The 62.5% D-glucose solution was dosed into the reactor at a rate of 2.88 g/min until 432.4 g (1.5 moles) had been added (150 min) After a short induction period, the mixture began to react exothermically as indicated by the jacket temperature having to run at colder and colder temperatures to maintain the material temperature of 25° C. After 25 minutes, the jacket was running at 12° C. and brown NO x gasses began to fill the headspace of the reactor and the liquid contents of the reactor turned emerald green in color. After 35 minutes, the jacket temperature was running at 4.5° C. to maintain a reaction temperature of 25° C. The headspace filled with dark brown NO x gas and the liquid mixture turned dark green. At this time, the reaction began to slowly subside taking about 6 hours for the jacket temperature to rise to 20° C. to maintain a reaction temperature of 25° C. The headspace continued to be filled with dark brown gasses and the liquid mixture continued to be dark green in color until the reaction was fully quenched/terminated by adding a liter of cold water to the reactor. The exothermicity, gas production, and green liquid color observations were shown to be typical of all nitric acid oxidations performed in a closed vessel under oxygen pressure regardless of molar ratio or batch size. Example 3 “Recirculated Oxidataion” [0062] A 62.5% (wt/wt) D-glucose solution was prepared by adding solid anhydrous D-glucose to deionized water in a screw-capped flask containing a stir bar. Next, the solution was heated to 65° C. with stirring. Once the glucose was adequately dissolved, the solution was cooled to 40° C. 411 g (4.5 moles) of concentrated nitric acid was added to the reactor and the iControl software was used to maintain a reaction temperature of 25° C. and an agitation speed of 200 RPM for the duration of the reaction. 0.31 g (4.5 millimoles) of sodium nitrite was added to the reactor and the reactor was sealed and pressurized with 1 barg oxygen. The 62.5% D-glucose solution was dosed into the reactor at a rate of 2.88 g/min until 432.4 g (1.5 moles) had been added (150 min) After a short induction period, the mixture began to react exothermically as indicated by the jacket temperature having to run at colder and colder temperatures to maintain the material temperature of 25° C. After 25 minutes, the jacket was running at 13.8° C. brown NO x gases began to fill the headspace of the reactor turning dark brown and the liquid contents of the reactor turned emerald green in color. At this time, slow recirculation of the reaction material was started and allowed to continue for the duration of the reaction. The material was recirculated slowly through a spray nozzle so that the material was removed from the bottom of the reactor and sprayed through the headspace of the reactor and back onto the liquid surface. Immediately, the reaction began consuming oxygen indicated by the LM Press 60 having to work harder in order to maintain the 1 barg pressure, and the brown NO x gasses in the headspace began to dissipate resulting in a colorless headspace and the emerald green color in the liquid lightened up. Within a few minutes, the reaction rate had slowed down enough that the jacket temperature could be run at 17° C. and the reaction temperature maintained at 25° C. The green color in the liquid began to fade to pale yellow and after 1 hour, and the jacket temperature was running at 20° C. to maintain a reaction temperature of 25° C. The early consumption of oxygen, and the reduction in exothermicity, gas production, and green liquid color were shown to be typical effects of recirculation during all nitric acid oxidations performed in a closed vessel under oxygen pressure regardless of molar ratio or batch size. Example 4 “Recirculated Oxidataion” [0063] A 62.5% (wt/wt) D-glucose solution was prepared by adding solid anhydrous D-glucose to deionized water in a screw-capped flask containing a stir bar. Next, the solution was heated to 65° C. with stirring. Once the glucose was adequately dissolved, the solution was cooled to 40° C. 205.5 g (2.25 moles) of concentrated nitric acid was added to the reactor and the iControl software was used to maintain a reaction temperature of 25° C. and an agitation speed of 200 RPM for the duration of the reaction. 0.46 g (6.7 millimoles)of sodium nitrite was added to the reactor and the reactor was sealed and pressurized with 1 barg oxygen. The 62.5% D-glucose solution was dosed into the reactor at a rate of 2.88 g/min until 648.6 g (2.25 moles) had been added (225 min). After a short induction period, the mixture began to react exothermically as indicated by the jacket temperature having to run at colder and colder temperatures to maintain the material temperature of 25° C. After 18 minutes, the jacket was running at 11.5° C. and brown NO x gases began to fill the headspace of the reactor and the liquid contents of the reactor turned emerald green in color. At this time, slow recirculation of the reaction material was started and allowed to continue for the duration of the reaction. The material was recirculated slowly through a spray nozzle so that the material was removed from the bottom of the reactor and sprayed through the headspace of the reactor and back onto the liquid surface Immediately, the reaction began consuming oxygen indicated by the LM Press 60 having to work harder in order to maintain the 1 barg pressure, and the brown NO x gasses in the headspace began to dissipate resulting in a colorless headspace. Within a few minutes, the reaction rate had slowed down enough that the jacket temperature could be run at 23° C. and the reaction temperature maintained at 25° C. The green color in the liquid began to fade to pale yellow and after 1 hour, and the jacket temperature was still running at 23° C. to maintain a reaction temperature of 25° C. The early consumption of oxygen, and the reduction in exothermicity, gas production, and green liquid color were shown to be typical effects of recirculation during all nitric acid oxidations performed in a closed vessel under oxygen pressure regardless of molar ratio or batch size. Example 5 General Methods for Examples 6-9 [0064] Oxidations were carried out in a Metler Toledo Labmax reactor which is designed to operate under computer control. The Labmax was fitted with an overhead agitation motor that drove a stir shaft fitted with four propeller type agitation paddles spaced equally throughout the height of the reactor. The reactor was made of glass and had a siliconoil filled jacket for cooling and heating. In addition, the Labmax was fitted with an overhead balance in communication with a metering pump for controlled dosing of reactants into the reactor, and RTD temperature probes to measure the temperature of both the reactor contents and the reactor jacket oil and a type K thermocouple was used to measure the temperature of the headspace. A Mettler Toledo LMPress 60 with a pressure transducer and internal PID loop processing was used to maintain oxygen pressure of 1.0 barg +/−0.04 barg within the reactor. A pressure manifold fitted with a pressure relief valve, a rupture disc and a pressure gauge was added to the head of the reactor. The reactor was equipped with a stainless steel condenser coil that extended inside the reactor from the top to about half way down the reactor. This condenser coil could be used to cool the top portion of the reactor independently of the oil jacket. The Labmax was controlled using iControl Labmax software version 4.0 which allows the user to specify reaction parameters, measures and logs data, and uses PID loop processing to maintain stable material temperatures during a reaction and dose reactants into the reactor at a given rate. The headspace of the reactor was plumbed into an external FT-IR gas cell with valves allowing gas samples to be removed from the headspace of the reactor. The gas cell was fitted into a Thermo Scientific Antaris Industrial Gas System (IGS) which could be used to take FT-IR spectra of the gas samples in real time. All spectra were obtained using the average of 8 scans from 700-3900 wavenumbers (i.e., inverse centimeters) and a resolution of 0.5 wavenumbers. The IGS was calibrated using certified gas standards. The gas standards were diluted with nitrogen using an Environics 4040 Diluter which allows the user to flow standard gas and nitrogen through the cell at predetermined flow rates in order to achieve desired gas concentrations. A 10-point calibration curve was generated for each gas analyzed. Due to the equilibrium relationship of NO 2 and its dimer N 2 O 4 , the concentrations of both species are expressed in terms of total NO 2 units where total NO 2 units equals the concentration of NO 2 plus two times the concentration of N 2 O 4 . Example 6 No cooling in headspace [0065] A 62.5% (wt/wt) D-glucose solution was prepared by adding solid anhydrous D-glucose to deionized water in a screw-capped flask containing a stir bar. Next, the solution was heated to 65° C. with stirring. Once the glucose was adequately dissolved, the solution was cooled to 40° C. 1238.9 g (13.5 moles) of concentrated nitric acid was added to the reactor and the iControl software was used to maintain a reaction temperature of 25° C. for 3 hours and 25 minutes then increase to 30° C. for 45 min then increase again to 35° C. for 75 min. An agitation speed of 100 RPM was used for the duration of the reaction. 0.93 g (13.5 millimoles) of sodium nitrite was added to the reactor and the reactor was sealed and pressurized with 1 barg oxygen. The 62.5% D-glucose solution was dosed into the reactor at a variable rate starting at 3.12 g/min and gradually increasing to 14.9 g/min until 1297.2 g (7.20 moles) had been added (205 min) After a short induction period, the mixture began to react exothermically as indicated by the jacket temperature needing to run at colder and colder temperatures to maintain the material temperature of 25° C. Gas samples were taken from the reactor every 20 minutes and analyzed with FT-IR for composition and quantification. After 25 minutes, brown NO x gasses began to fill the headspace of the reactor and the liquid contents of the reactor turned emerald green in color. After 4.5 hours the total NO 2 units concentration had built to 70% in the headspace of the reactor then slowly decreased to about 59% at the end of the oxidation. Despite the liquid temperature being maintained at 25° C.-35° C. the temperature of the headspace slowly built to a maximum of 40° C. reaching this maximum at the same time the total NO2 units concentration reached a max of 70%. This temperature build was due to the exothermic reaction 2 NO+O 2 2 NO 2 . Example 7 Cooling in Headspace [0066] A 62.5% (wt/wt) D-glucose solution was prepared by adding solid anhydrous D-glucose to deionized water in a screw-capped flask containing a stir bar. Next, the solution was heated to 65° C. with stirring. Once the glucose was adequately dissolved, the solution was cooled to 40° C. 1238.9 g (13.5 moles) of concentrated nitric acid was added to the reactor and the iControl software was used to maintain a reaction temperature of 25° C. for 3 hours and 25 minutes then increase to 30° C. for 45 min then increase again to 35° C. for 75 min. An agitation speed of 100 RPM was used for the duration of the reaction. The headspace condenser was then activated and allowed to run at −12° C. for the duration of the reaction. 0.93 g (13.5 millimoles) of sodium nitrite was added to the reactor and the reactor was sealed and pressurized with 1 barg oxygen. The 62.5% D-glucose solution was dosed into the reactor at a variable rate starting at 3.12 g/min and gradually increasing to 14.9 g/min until 1297.2 g (7.20 moles) had been added (205 min) After a short induction period, the mixture began to react exothermically as indicated by the jacket temperature needing to run at colder and colder temperatures to maintain the material temperature of 25° C. Gas samples were taken from the reactor every 20 minutes and analyzed with FT-IR for composition and quantification. After 25 minutes, brown NO x gasses began to fill the headspace of the reactor and the liquid contents of the reactor turned emerald green in color. After 4.5 hours the total NO2 units concentration had built to 55% in the headspace of the reactor then slowly decreased to about 50% at the end of the oxidation. The headspace condenser was able to keep the temperature of the headspace below 20° C. despite the exothermic reaction 2 NO+O 2 2 NO 2 . This lower temperature shifts the equilibrium of the dimerization of NO 2 to N 2 O 4 allowing for more N 2 O 4 to form then enables N 2 O 4 to condense into the liquid phase. Once in the liquid phase the N 2 O 4 can react with water to make HNO 3 and HNO 2 according to the reaction N 2 O 4 +H 2 0 HNO 2 +HNO 3 . The higher concentration of nitric acid in the liquid phase was indicated by the lower concentration of total NO 2 units in the gas phase. At the end of the oxidation, the jacket temperature of the reactor was adjusted so that the headspace could be cooled to 5° C. This resulted in the total NO 2 units concentration in the headspace gradually diminishing to 18% over a 60 min period allowing for more nitric acid recovery. Example 8 No Cooling in Headspace [0067] A 62.5% (wt/wt) D-glucose solution was prepared by adding solid anhydrous D-glucose to deionized water in a screw-capped flask containing a stir bar. Next, the solution was heated to 65° C. with stirring. Once the glucose was adequately dissolved, the solution was cooled to 30° C. 1110 g (12.2 moles) of concentrated nitric acid was added to the reactor. Then 1.1 g (15.9 millimoles) of sodium nitrite and 1753 g of the above dextrose solution (6.1 moles) were added to the reactor and the iControl software was used to maintain a reaction temperature of 35° C. and an agitation speed of 300 RPM was used for the duration of the reaction. The reactor was then sealed and pressurized with 1 barg oxygen. After a short induction period, the mixture began to react exothermically as indicated by the jacket temperature needing to run at colder and colder temperatures to maintain the material temperature of 25° C. Gas samples were taken from the reactor periodically and analyzed with FT-IR for composition and quantification. After about 30 minutes, brown NO x gasses began to fill the headspace of the reactor and the liquid contents of the reactor turned emerald green in color. After 3.9 hours the total NO 2 units concentration had built to 57% in the headspace of the reactor then slowly decreased to about 46% at the end of the oxidation. Example 9 Cooling in Headspace [0068] A 62.5% (wt/wt) D-glucose solution was prepared by adding solid anhydrous D-glucose to deionized water in a screw-capped flask containing a stir bar. Next, the solution was heated to 65° C. with stirring. Once the glucose was adequately dissolved, the solution was cooled to 30° C. 1110 g (12.2 moles) of concentrated nitric acid was added to the reactor. Then 1.1 g (15.9 millimoles) of sodium nitrite and 1753 g of the above dextrose solution (6.1 moles) were added to the reactor and the iControl software was used to maintain a reaction temperature of 35° C. and an agitation speed of 300 RPM was used for the duration of the reaction. The reactor was then sealed and pressurized with 1 barg oxygen. After a short induction period, the mixture began to react exothermically as indicated by the jacket temperature needing to run at colder and colder temperatures to maintain the material temperature of 25° C. Gas samples were taken from the reactor periodically and analyzed with FT-IR for composition and quantification. After about 30 minutes, brown NO x gasses began to fill the headspace of the reactor and the liquid contents of the reactor turned emerald green in color. After 3.9 hours the total NO 2 units concentration had built to 50.0% in the headspace of the reactor then slowly decreased to about 40% at the end of the oxidation. The headspace condenser was able to keep the temperature of the headspace below 20° C. despite the exothermic reaction 2 NO+O 2 2 NO 2 . This lower temperature shifts the equilibrium of the dimerization of NO 2 to N 2 O 4 allowing for more N 2 O 4 to form then enables N 2 O 4 to condense into the liquid phase. Once in the liquid phase the N 2 O 4 can react with water to make HNO 3 and HNO 2 according to the reaction N 2 O 4 +H 2 0 HNO 2 +HNO 3 . The higher concentration of nitric acid in the liquid phase was indicated by the lower concentration of total NO 2 units in the gas phase. The total NO 2 units concentration was consistently 5%-8% lower in this experiment then in the previous example (which was identical in every way except headspace temperature). At the end of the oxidation, the jacket temperature of the reactor was adjusted so that the headspace could be cooled to −8° C. This resulted in the total NO 2 units concentration in the headspace gradually diminishing to 13% over a 60 min period allowing for more nitric acid recovery. [0069] It is understood that the foregoing examples are merely illustrative of the present invention. Certain modifications of the articles and/or methods may be made and still achieve the objectives of the invention. Such modifications are contemplated as within the scope of the claimed invention.

A process utilizing nitric acid and oxygen as co-oxidants to oxidize aldehydes, alcohols, polyols, preferably carbohydrates, specifically reducing sugars to produce the corresponding carboxylic acids.

This is a continuation of co-pending application Ser. No. 07/343,663 filed on Apr. 27, 1989, now U.S. Pat. No. 5,245,329. BACKGROUND OF THE INVENTION This invention relates to access control, and more particularly it is concerned with a high security access control system involving credit card type keys or mechanical keys and locks as well as keyholder authentication to prevent unauthorized use of a key. A number of different types of access control systems and devices have existed in use or in previous patents--for example, the systems of National Computer Systems, Inc. and Continental Instruments, Inc. Cylinders and keys having mechanical configuration in combination with electrical, magnetic or optical locking or unlocking devices have also been known. See, for example, U.S. Pat. Nos. 4,603,564, 4,658,105, 4,633,687, 4,458,512, and 3,733,862. In some of these devices, keys and cylinders could be coded by the manufacturer or by the user, with the non-mechanical aspect of the key affording additional security against opening of a lock without the proper key. In these combinations of mechanical and non-mechanical security features on a key, the non-mechanical code or configuration or pattern simply added to what was required to open the lock, generally not carrying other readable data useful for other purposes. U.S. Pat. No. 4,537,484 shows one example of a fingerprint reader system for use in identity verification. Another such reader is manufactured by ThumbScan, Inc. of Oakbrook Terrace, Ill., for the purpose of computer terminal security. Such scanners have also been suggested for use in identification in access control systems involving granting of entry only to authorized persons. However, these systems have not cooperated with keys and locks which could be used in the same facility. Also, they have generally required processing of the attempted user's fingerprint in a central processor which would have to either compare the attempted user's fingerprint with hundreds or thousands of stored fingerprints in a database, or would receive a user identification number keypunched in by the person seeking access, and then look up a database-stored fingerprint corresponding to that code and make the comparison. Such a central look-up and comparison would involve a great deal of central computer memory and power, and the use of many-conductor bus cables between each access control point and the central processor, and would tend to require considerable time or a very high powered computer, to complete the access control decision. This equipment and installation of the cables can involve great cost, particularly when added to an existing building. A different approach to access control decision making is taken by the present invention described below. In a preferred embodiment, a keyholder carries a key which not only has a mechanical configuration for accessing mechanical locks (or a card type key with non-mechanical lock access features), but also carries encoded data representing a personal identifying code or feature of the keyholder, as well as a simple identity number or code. The high security authentication comparison can be made directly at the access control point, by a small processor board located behind a reader panel. SUMMARY OF THE INVENTION In accordance with the access control system of the present invention, the system includes a series of mechanical keys or card type keys (electronic, magnetic, hole-punched, etc.) which can optionally be high security keys themselves. At least some of the keys carry encoded data which represent a personal feature of the intended keyholder assigned to that key. In preferred embodiments, the personal identifying or authenticating feature of the keyholder is a "biometric" feature, such as a fingerprint, a retina scan, a facial photograph or other feature unique to the intended keyholder. A retina scanner is disclosed in U.S. Pat. No. 4,685,140, for example. The encoded data preferably is placed on the bottom edge of a mechanical key, and may it be in a groove formed in that edge of the key. Alternatively, the data may be placed on one surface of the key's head. It may be read by swiping it through a reader slot. On a card type key the encoded data can be in a stripe on the card surface. Optical data storage such as used in audio and video discs may be used, or high-density optical storage such as disclosed in U.S. Pat. Nos. 4,145,758, 4,304,848 or 4,503,135. The key also has a mechanical configuration (or lock accessing feature) matched to certain mechanical lock cylinders (or non-mechanical locks) to which the intended keyholder is to have access. Some of these may be lower security areas, and some may combine the mechanical or non-mechanical lock features with the user authentication access control feature, for high security. It is a central feature of the present invention, and an important distinction from prior access control systems or high-security keys, that the key itself bears encoded data which is not merely picked up by the lock apparatus to establish a higher security in allowing rotation of a lock cylinder (or opening of a non-mechanical lock), but which carries digitized information relating to a personal authenticating feature of the intended user of the key, for reading and making a comparison before access is granted to the attempted user. At some high-security access control point in the system, the keyholder places his key into a keyway or slot or against a reader, which reads the encoded, digitized information which relates specifically to the intended keyholder. This information as read is briefly stored in a memory associated with a small processor connected to the key reader. The keyholder may then be prompted to place a selected finger against a transparent window of a fingerprint reader. The fingerprint reader scans the fingerprint, and this scanned information is compared with the encoded information. It should be understood that other features unique to the intended keyholder can be used, as mentioned above such as a retina scan or a photograph. If the actual fingerprint as read matches sufficiently closely to the fingerprint as encoded and stored on the key, a provisional decision is made by the small processor to grant access to the keyholder. In some applications a time/date access decision will also be required, with that decision made by a central processor, based on whether the particular keyholder is to be permitted access to that area at that particular time. Optionally the keyholder can also be required to use his key to access a lock at the same location. The key can be used to rotate one cylinder, for example, while a second lock or bolt is released electrically, automatically, based on the decision of the system to grant access. In a preferred embodiment the keyholder can be granted access by an electric release or electric strike based on the positive user authentication decision (with or without time/date decision from a central processor, as above), without using the mechanical key configuration (or other lock accessing features). In this case, the mechanical key configuration is used for other locks in the system, wherein lower security is required, with the encoded key enabling the keyholder to carry only one item for access to all permissible locks. With the authentication comparison made directly at the access control point, and no personal authentication (e.g., fingerprint) data required to be imported from any remote database at a central computer, the access control system of the invention can employ only a very small cable connecting each access control point to the central processor, e.g. two conductors, for time/date decision from the central processor and for reports to the central processor. Whenever access is attempted, the small local processor at the access control point can send a report which includes an identification of the keyholder, derived from encoded information on the key, and a "yes" or "no" decision as to whether access was permitted. The time of day and the access control point location can be added to the report by the central processor. The system also enables access management for allowing different personnel entry at different times of day or different days of the week or calendar days, etc. The small on-site processor can be programmed to allow access to certain personnel by personnel code or number (at certain times), but preferably, for large numbers of personnel this is controlled by the central processor (again via a simple two-conductor cable). This can be adjusted, or access can be canceled for certain personnel (such as discharged employees) by instruction input at the central processor. In another preferred embodiment of the invention, at each high-security access control point there is a keyway configured specifically for keys of keyholders who are to have access at this point. The keyway is at the key reader, instead of (or in addition to) the keyway being in a lock cylinder. When a key of the correct type is inserted into this keyway, the reader scans the encoded data. Keys of the wrong mechanical configuration cannot be inserted, so that access will not be possible. The keyway can be of a high-security type, rather than one in common use. In addition, a high-security key cut configuration can be used, such as of the type shown in U.S. Pat. Nos. 4,635,455 and 4,732,022 assigned to Medeco Security Locks, Inc. Such key cuts are made at an oblique angle with respect to the side faces of the key. For the purposes of this invention, at least one pin can be cooperative with the keyway, with the pin having an angled bottom end which becomes rotationally oriented when it engages against the angle cut key. If the pin does not engage properly against the key's angle cut, access can be automatically denied (even though the keyholder identification will preferably still be read from the key). This enables a report to be made to the central processor, regarding the attempted entry, and the fact that a certain keyholder's key was apparently defective or was attempted to be used improperly, at the wrong access control point. An alarm can be activated under such condition of attempted improper key use, or a silent signal can be sent elsewhere in the system where preferably personnel will be alerted. The same alarm or signal can be sent whenever access is denied in any of the various forms of the system of the invention, and for any reason, including the reason that the keyholder's fingerprint (or other personnel identifier) did not match the code on the key. If desired for extra security, the keyway provided at the key code reader can comprise an actual lock cylinder which must be rotated before a positive access decision can be completed. Such a cylinder can include a full compliment of pins in a nigh-security configuration if desired, so that a combination of user authentication and mechanical keying is relied upon for added security. In one aspect, the invention comprises a card type or mechanical key, either of the pin type or of other high-security type currently in use, such as the dimple type or the tubular type, in combination with encoded data secured to the key--data which is readable by a scanner or reader and which does not directly help enable the keyholder to rotate the key in a lock. Instead, the encoded data is representative of some personal identifying, authenticating feature known by or held by or on the person of the intended keyholder. Such an authenticating feature preferably comprises a biometric feature such as a fingerprint scan, a retina scan, a voice pattern or a facial photograph; more broadly speaking, however, it can include other items such as a memorized number or code which is known only to the intended keyholder or keyholders and which must be input to a keyboard by the keyholder to be matched with what is read from the key. The prior art did not contemplate a mechanical key which itself bore such separate data which would enable authentication of the keyholder attempting access. The encoded information on the key, if it represents fingerprint, retina scan, voice or other characteristic of the intended keyholder, also preferably includes a central keyholder number or code, for the purpose of reporting the identity of the intended keyholder in a transaction record whenever the key is attempted to be used for access. In another aspect the invention comprises a card type key having normal lock accessing features, encoded data relating to the personal authenticating feature, and a photograph of the intended user, with other appropriate printed matter to allow the card to be used as an identifying card or badge. In a still further aspect, the card can at a minimum have encoded data carrying a biometric feature to be used in an access control system of the invention having corresponding biometric readers (e.g. fingerprint). It is therefore among the objects of the present invention to improve over previous access control systems and high-security mechanical key systems by encoding keys with a user authentication code which can be read by scanners or readers at access control points, so as to prevent anyone but an authorized, intended keyholder from gaining access at such control points. An associated object is to provide an access control system wherein the key configuration or access control feature is effective to open locks at other points where keyholder authentication is not required, thus enabling personnel to carry only one key for access to both high-security points and lower-security points. These and other objects, advantages and features of the invention will be apparent from the following description of preferred embodiments, considered along with the accompanying drawings. DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic drawing indicating components of an overall access control system in accordance with the principles of the present invention. FIG. 2 is a view showing a mechanical key forming a part of the system of the invention in one embodiment, with encoded data formed on or secured to the key. FIG. 3 is a frontal elevation view illustrating elements of the system of the invention in a preferred embodiment, at one access control point in the system. FIG. 4 is a schematic system diagram partially in the form of a block diagram, indicating several access control points and security components, and indicating some information and control flow to and from a central processor, in accordance with one embodiment of the system of the invention. FIG. 5 is a schematic block diagram indicating information which might be included in the encoded data on the mechanical key indicated in FIG. 2, and illustrating flow of information from the key and from a fingerprint scanner which may be included, and showing operation of the system to grant access or deny access and to make reports. FIG. 6 is a schematic view, partially in perspective, showing elements of an optical key reader which may be included in the system of the invention. FIG. 7 is a schematic diagram showing an embodiment of a system of the invention wherein access control points are formed into groups. FIG. 8 is a flow diagram indicating operation of the system in accordance with one preferred embodiment of the invention. FIG. 9 is a flow diagram illustrating the use of the access control system of the invention with an employee time management and payroll system. FIG. 10 is a perspective view showing a credit card type key with non-mechanical lock access features and with encoded data representing a personal identifying feature of-the keyholder. FIG. 11 is a view similar to FIG. 10, showing a card with encoded data representing a personal biometric identifying feature of the keyholder and also a photograph of the keyholder, so that the card can be used as a security pass as well as an authenticating pass for high security access. DESCRIPTION OF PREFERRED EMBODIMENTS In the drawings, FIG. 1 shows schematically an access control system 10 in accordance with one embodiment of the present invention. Principal components of the system 10 include a series of high security access control points 12, including different security levels at 12a and 12b, and a series of lower security access control points 14. The system also includes a central processor unit 15 with associated memory, as well as a number of distributed mechanical keys 16 which are controlled in distribution and each registered to a specific intended keyholder or keyholders. As schematically indicated in FIG. 1, the processor unit 15 is connected only to the high security access control points 12. The processor 15 may have a programmer unit 17 and an optional printer 18 connected to it. As illustrated in FIG. 2, a mechanical key 16 as used in the system includes a mechanical configuration 19 for engagement with a mechanical lock, and it also includes encoded data related to high security access control located, for example, at a position 20 on or in the bottom edge of the key 16. The encoded data may alternatively be located on the head 22 of the key or on another edge, such as edges 24 of the key head 22. In these alternate locations the encoded data can be read by placing the key against a reader, or by insertion into a slot or by swiping through a slot. Although FIG. 2 shows a conventional mechanical key configuration, for use with pin and shear plane type rotatable lock cylinders, the mechanical key 16 can also be of the higher security type with angle cuts as shown in U.S. Pat. No. 4,732,022 referenced above, or it can be a tube-shaped key of type often used on computers and burglar alarms, etc., or a dimple type key or any other type of mechanical key. It should be understood that the present invention also applies to credit card type keys, hole punched type flat keys, and other flat plastic or metal card type keys, as well as conventional mechanical keys. The term "key" as used herein and in the claims is intended to encompass all such keys, except accompanies by the term "mechanical." An example of one kind of credit card type key 16a is shown in FIG. 10. All of FIGS. 1 and 3 through 9, and the accompanying description, should be understood as encompassing the use of any of a number of such card type keys, in many different configurations and with different types of lock accessing features. The card type key 16a in FIG. 10 may have hole-punched type lock access features 21, and a small strip of encoded data 23 carrying the personal identifying feature, such as a biometric feature. Each key has two separate functions--a mechanical function of opening mechanical (or magnetic, hole-punch, etc.) locks in the system, and an electronic or data function involving the carrying of data as discussed above. The data borne by the key 16, in accordance with preferred embodiments of the invention, does not itself open a lock or help enable opening of a lock or enable access at an access control point. Rather, it includes information specific to the intended keyholder, for authenticating the keyholder when access is attempted by a keyholder using the key. At the minimum, the encoded data will include a personal code, e.g. a combination of numbers which are memorized by the intended keyholder and which only the intended keyholder (and perhaps supervisory personnel) is supposed to know. A comparison is made between the encoded information, or some of the encoded information from the key, and similar information input in another way (e.g. input manually by the keyholder on a number keyboard or input via fingerprint). Thus, the system of invention differs from prior systems, even in the form of the minimum system just described, in that when access is attempted, the system does not retrieve a secret code from a central database or processor, for comparison with a code input by the attempted user. Instead, the secret code is carried on the key itself, and can be read by a small local processor at the access control point and there compared directly with a code input by the attempted user. The on-site comparison is one important feature of the invention. However, in preferred embodiments of the invention the keyholder authenticating data carries not merely a secret number or code memorized by and known only to the intended keyholder, but instead or in addition carries data related to a personal identifying characteristic or biometric feature of the intended keyholder. This identifying biometric feature or characteristic advantageously can be the intended keyholder's fingerprint, but it could also be any other unique personal characteristic as discussed above, such as a digitized facial photograph or a voice pattern or even a retina scan. At each high-security access control point in such a preferred system, there is provided both a key reader for reading the encoded data on the key, and a reader of the attempted user's biometric feature such as fingerprint, voice pattern, photograph, retina scan, etc. FIG. 3, showing an example of a high-security access control point, shows a fingerprint reader window 25 and a keyway 26 for reading of the encoded data on the key. A reader panel 28 shown in FIG. 3 also may include an optional key pad 30, for manually inputting a code, which can be an alternative to a fingerprint reader or other personal identifying feature reader as discussed above, in a simple form of the system. Fingerprint readers are well Known and well developed. For example, see U.S. Pat. No. 4,537,484 referenced above. Retina scanners are also known and effective for distinguishing between individuals and matching a known retina scan of a person, as discussed above. If a retina scanner is used in the system of the invention, the window 25 can have behind it a retina scanner. However, many individuals may find retina scanners objectionable. An individual's facial photograph can be digitized and stored as encoded data carried on the key 16. The window 25 in FIG. 3 can have behind it a camera, such as a video camera, for producing a video image which can be scanned by associated electronics and compared with the image encoded on the key 16, to determine whether a close enough match exists. If voice identification is used, a microphone can be included on the panel 28 shown in FIG. 3, indicated as grid lines 32 in FIG. 3. It should be understood that ordinarily not all of the items 25, 30 and 32 will be included on the access control panel 28--they are illustrated primarily as alternatives. When a keyholder approaches a high-security access control point such as exemplified in FIG. 3, he may not be required to actually use his key in a keyway (indicated at 34) of the door, gate, computer, safe, drawer, etc. Instead, the keyholder positions his key 16 in a position to be scanned for the encoded data (as by inserting it into a keyway such as shown at 26) and he inputs his personal identifying or authenticating feature, e.g. his actual fingerprint, to be compared with the data from the key, using the panel 28. If a match is found, access preferably is granted electrically (optionally other criteria may first be required as described below). Thus, if the access control point has a door 36 such as shown in the example of FIG. 3, the panel electronics can actuate an electric release 38 in the door jamb 40, or an electric strike 41 in the door 36. This enables the authenticated keyholder to merely pull or push the door 36 open, without rotation of any lock cylinder in the door. However, in an embodiment of the invention the keyholder may also be required to use his key 16 in a keyway 34 in the door. For example, the door may include a deadbolt or catch (not shown) which cannot be released by any key within the possession of a certain class of personnel, but which will be released, allowing the door to open, by an electric door jamb release mechanism 38 or electric strike mechanism 41 controlled by the panel 28. In addition, a different mechanical strike or deadbolt 43 can be controlled by the mechanical lock cylinder 34, which the authenticated keyholder will be required to use in addition, when access has been granted electronically via the panel 28. This can also serve as mechanical backup security in the event the electronic system is shut off or malfunctions. Alternatively, a keyway 34 can be provided in the door which will receive a different key, other than the key 16 in the possession of the keyholder. The special key for the keyway 34 can override the electronic system under certain conditions such as an emergency, but with special high-security keys for this keyway 34 only possessed by certain high-security personnel. In addition, preferably a record is made and sent to a central processor whenever the door is opened by such a special key, without authentication via the panel 28. This is discussed further below with reference to FIGS. 4 and 5. As another alternative, the keyway 34 shown in the door 36 can fit the keyholder's key 16, but with the cylinder associated with keyway 34 normally disabled against unlocking the door in this way, thus normally requiring the panel 28 to release the door. The disabling mechanism for the key cylinder 34 can be electrically released, such as in times of emergency or certain times of day when high-security access control is not required. During these periods, access can be gained, e.g. the door 36 can be opened, merely using the mechanical key 16 and the keyway 34, in the conventional manner. Such a cylinder's disabling mechanism can simply be a solenoid operated or otherwise electrically actuated pin internal to the door 36, which locks the cylinder 34 against rotation except when electrically released. FIG. 3 shows an optional door or cover 25a (dashed lines) which can be included to cover the reader window 25 when not in use. The cover 25a can be slidable and solenoid operated--normally closed but openable automatically when a key is inserted in the keyway 26. The cover can comprise a pair of doors which slide in and out from left and right or top and bottom. In a system with date/time access control the opening of the cover 25a can be delayed until after a signal is received from the central processor authorizing entry to the particular personnel number or key number at the particular time. In preferred embodiments of the overall system of the invention, once the keyholder has gained access at the access control point 12 shown in FIG. 3 (e.g. he has opened the door 36 and entered), the keyholder may encounter additional high-security access points 12, or he may simply encounter lower security access points 14 (FIG. 1). These latter access points 14 will require only the mechanical key 16 with its configuration 19, without use of the encoded data. In this way, the single access item (the mechanical key) is used for several purposes within the system. FIG. 1 shows that the high-security access control points 12 may include different levels of security. The highest security is illustrated at 12a, where a fingerprint verification reader 24 and a keyway for a key code reader 26 are both included; at 12b, only the keyway/key reader 26 is included, without fingerprint verification. At this type access control point, the key identification number or code is read from the key and sent to the processor unit 15, which will send back a signal to grant access only if the person associated with that key number is to be admitted at the particular date and time involved. This information is stored in memory at the processor 15. Similarly, time/date control may be a part of the access decision at all or some high-security points 12a depending on the type of facility and whether differentiation is needed among personnel and as to dates and times of permitted access. Each user's key preferably includes the encoded key number or ID number which is read by the key reader. This is sent to the central processor 15, which determines whether access is restricted at this particular time, and sends back a signal to the panel 28 confirming or denying access. This decision, as well as the comparison, must be positive for access to be granted. FIG. 4 is another schematic representation showing several access control points including a high-security access control point 12, in elevational section. Various components of the security panel 28 are shown, as well as connection to the central processor 15. As in FIG. 3, FIG. 4 shows the system with a fingerprint reader 42, behind the window 25, as one preferred embodiment; however, it should be understood that other types of personal authentication biometric feature reading devices may be substituted for the fingerprint reader 42, as mentioned above. As indicated in FIG. 4, and also in reference to FIG. 5, the control panel includes a key scanner or reader 44 for reading the encoded data on the key. This may be associated with a keyway 26 as illustrated in FIG. 3, although the encoded data be alternatively be on the head of the key (or on a card key, as discussed above), with the key simply placed up adjacent to the key scanner 44. If a keyway is included, the encoded data (which may be optically encoded) may be scanned using the movement of the key in entering the keyway. This is shown schematically in FIG. 6. Data on the key, which may be encoded in the recess 20, is scanned by a beam such as a focused laser beam 44a emanating from a laser diode 44b and focused by focusing optics 44c. As the key 16 is mushed into the slot or keyway 26, the encoded information is moved mast the beam 44a and this movement produces a scan, eliminating the need for a beam scanner. A reflection signal from the encoded information returns and is reflected by a beam splitter mirror 44d and another mirror 44e to a photodetector 44f. The electrical voltage signal from the detector 44f is fed to a special data decode processor 44g and the decoded signal is sent to the local processor 46. Alternatively, the raw signal from the detector 44f can go directly to the local processor 46, provided with decode software. FIGS. 4 and 5 also show schematically an electric release or electric strike 45 in the door jamb or door, to be activated by the panel 28 when a keyholder is authenticated and granted access. A small local processor 46 at the panel 28 receives inputs from the electronic key scanner 44 and from the fingerprint reader 42, with the scanned fingerprint preferably digitized in the manner the encoded data is digitized. The processor 46 makes a comparison to determine whether the live fingerprint just scanned is close enough to the fingerprint data as digitized in the encoded data to constitute a match, within preset criteria, and if so, a preliminary decision is made to grant access. If time/date control is not included the electric release or electric strike may be activated at this point to admit the person. At the same time, as shown in FIGS. 4 and 5, the key scanner or reader 44 preferably reads an encoded identifying number (or other ID code) from the data carried by the key, and this information is sent to the central processor 15. It can either go into the local processor and from there to the central processor in a report, or directly to the central processor as shown in FIG. 5, to be there correlated with an authentication report as discussed below. If date/time access control is desired, this ID information is used by the central processor 15 to determine (via a database) whether access should be granted at this time. As indicated in FIG. 5, and in the flow chart of FIG. 8, both "yes" decisions are required in order for the electric release or strike 45 to be activated. The central processor looks up the ID number and checks whether that ID number should be permitted entry at the particular date and time of attempted entry. The ID information is also used to make a record of the transaction in the central processor 15. A transaction record or report 47 (FIGS. 5 and 8), sent to the central processor 15, can comprise only the access decision, i.e. yes or no, from the authentication comparison. A signal carrying this information can be sent to the central processor with a simple two-conductor cord, indicated by a line 48 shown in FIGS. 4 and 5. In the central processor 15 this report is correlated the personnel or key identifying number or code (ID number), which has been received almost simultaneously. The flow chart of FIG. 8 outlines functions carried out in a preferred embodiment of the system of the invention. These functions are illustrated without regard to which processor or other element is used to perform each function. The flow chart does not need further explanation, beyond the description on the chart and the description herein. FIG. 4 also indicates a form of switch 50, such as a mechanical limit switch or photoelectric sensor, which optionally may be actuated every time the door or gate or drawer, etc. 36 is opened. This information can be sent to the central processor (via line 52, which can be the same conductor wire as represented by the line 48), and it will normally match a positive access decision as described above. If the door is ever opened in the absence of a positive access decision, a report of such occurrence can be made by the central processor (it can be printed out via the printer 18). An audible alarm and/or indicator light can also be activated, if desired. FIG. 7 shows schematically a variation of what has been described in the other drawing figures. In FIG. 7 an access control system 70 in accordance with the invention includes a large plurality of high-security access control points 72 (labeled in FIG. 7 as 72a, 72b and 72c). Each of these access control points 72 may be similar in most respects to the high-security access control points 12 shown in FIGS. 3, 4 and 5. However, in the embodiment shown in FIG. 7 these access control points 72 are grouped into an "A" group, a "B" group and a C group. The A group of access control points 72a are each connected to a processor A, with the B group connected to a processor B and the C group connected to a processor C. The access control points within a group are Physically located close to one another, so that they can easily be connected, as by a two-conductor wire, to the processor for the group. Each of the processors A, B and C serves the function of the small processor 46, but is of somewhat larger capacity so that a group of access control points can be served. The system 70 also includes a central processor 15 such as described above with reference to FIGS. 1, 4 and 5. With the group processors being of larger capacity than the local processors 46 in the earlier embodiment, the processor 15 may be used to program the group processors A, B and C to handle some functions which otherwise would have been performed by the main processor 15. This can include the date/time control information discussed above, which can also be used to exclude certain personnel (by ID number or key number) who should no longer have access, such as discharged employees. The processor 15 is also used, as in the previous embodiment, for maintaining a database and for receiving reports from the processors A, B and C and for itself generating reports. The printer 18 may be included, as above, as well as a display monitor 74. FIG. 9 is a simple block diagram illustrating the interconnection of the system of the invention with an employee time management system, as for time and payroll management of hourly employees. FIG. 9 shows that an employee on beginning a work shift will approach one or more high-security entry doors (which can include non-authenticating access points 12b shown in FIG. 1). The employee inserts his key, which is read at least for the employee number or ID number (block 80), and preferably also is read for the authenticating feature as indicated in the figure. After the central processor checks a database for time/date control (block 82), and the employee is approved to enter at this time, and assuming keyholder authentication is positive, if necessary, as in the block 84, the door is released and access is permitted (block 86). This causes a report 88 to be created, indicating the date and time of entry and the employee identity. The report is sent to time management and payroll 90, which may be operated by the central processor. When the same employee exits, at the end of a shift or for a meal break, he again inserts his key, but into a key reader at the inside of the door, which signifies that he is exiting. This is indicated in the block 92. Keyholder authentication (block 95) preferably is again required to assure that the proper employee is checking himself out. The employee removes his key and exits (block 94). The opening of the door itself does not require keyholder authentication or even key insertion, but properly taking these steps is in the employee's interest for payroll records. A report 96 is generated, which goes to time management and payroll 90. The record of the employee's entry and exit times enables the compilation of a weekly (or biweekly, monthly, etc.) time report and the automatic printing of checks for the employee (block 98). FIGS. 10 and 11 show card type access control devices encompassed by the invention. The credit card type key 16a of FIG. 10 was discussed above. In FIG. 11 a different type of card 100 is shown, not necessarily containing any locks accessing feature such as the feature 21 shown in FIG. 10. The card 100 serves as an ID card or security pass, preferably with a photograph 102 of the intended bearer. It also serves as an access control device, having a biometric feature (e.g. fingerprint) encoded in a strip of encoded data 23. Thus, the card 100 is used by the bearer for accessing high-security access points in the manner described with reference to FIGS. 1 and 3 through 9, while also serving as a security pass visual inception. A principal difference is that the card 100 may not be capable of directly accessing any lock. The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to these preferred embodiments will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims.

An access control system combines card type keys or mechanical keys and lock cylinders with keyholder authentication, so that only the authorized keyholder or keyholders can use a key at an access control point. The access control point can be a door, gate, drawer, safe, safety deposit box, computer terminal or other situation wherein high security is desirable. In a preferred embodiment, the access control system includes a series of mechanical keys (or card type keys) having encoded data stored on the bottom edges of the keys. The encoded data may be in the form of a bar code or optical data storage, either directly formed onto the key or on a strip of plastic or other material bearing the encoded data, secured to the key. In one form of the invention, user authentication involves a biometric feature such as a fingerprint of the intended keyholder. The fingerprint is digitized, encoded and placed on the bottom edge of the mechanical key for that intended keyholder, preferably along with an encoded keyholder identifying number. An authentication reader at a high security access control point includes a keyway with a reader for the encoded data representing the encoded fingerprint, and also a fingerprint reader for reading the user's fingerprint at each instance of attempted entry. Comparison of the attempted user's fingerprint with the stored fingerprint is preferably made directly at the access control point, so that only the access decision and a keyholder identifying code need to be sent to a central processor.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of application Ser. No. 14/068,626 which claims the benefit of U.S. Provisional Application No. 61/720,894, filed Oct. 31, 2012 and U.S. Provisional Application No. 61/720,931, filed Oct. 31, 2012, all of which are herein incorporated by reference in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to a drive mechanism, and more particularly to a drive mechanism for an electric toothbrush. BACKGROUND OF THE INVENTION [0003] After a certain amount of use, the brush heads on electric toothbrushes often wear out and need to be replaced. A drive mechanism that is efficient and includes parts that are easily connectable between the new brushing attachment and handle is desirable. SUMMARY OF THE PREFERRED EMBODIMENTS [0004] The invention generally is a drive interface between a powered toothbrush handle that includes a battery, motor, and gear train that rotates a drive shaft located at an attachment interface, such as the attachment mechanism disclosed and claimed in pending U.S. Non-provisional patent application Ser. No. 14/068,733, filed on Oct. 31, 2013 which is incorporated herein by reference for all purposes, to power a removable brushing attachment. The drive interface includes features that help provide proper alignment during connection and drive torque during operation. [0005] In accordance with a first aspect of the present invention there is provided a toothbrush that includes a brushing attachment and a handle. The brushing attachment includes a main body portion with a hollow neck with an attachment opening and a head with a cleaning member opening, a drive shaft positioned in the neck, a cleaning member drive mechanism matingly engaged with gearing on the drive shaft, and a cleaning member extending through the cleaning member opening in the head and operatively associated with the cleaning member drive mechanism. The drive shaft includes a spline drive on one end and the gearing on the opposite end and is positioned adjacent the attachment opening in the neck. The handle includes a main body portion that houses a motor, and a brushing attachment connection receiver extending upwardly from the main body portion that is at least partially received in the attachment opening in the brushing attachment. The brushing attachment connection receiver includes a recess defined therein that receives a drive hub therein. The drive hub includes a grooved recess defined therein that receives the spline drive. In a preferred embodiment, the grooved recess includes a straight section and an incline section, and the straight section has smaller outer diameter than the outer diameter of the incline section. Preferably, the grooved recess includes at least one drive groove having an inner surface and at least one guide groove having an inner surface, and there is clearance between the spline positioned in the guide groove and the inner surface of the guide groove. Put another way, the guide groove is larger in volume than the drive groove. In an embodiment, the grooved recess includes a plurality of alternating drive grooves and guide grooves. [0006] In accordance with another aspect of the present invention, there is provided a brushing attachment for a toothbrush that includes a main body portion, drive shaft, cleaning member drive mechanism, and a cleaning member. The main body portion includes a hollow neck and a head, and the neck includes an attachment opening and the head includes a cleaning member opening. The drive shaft is positioned in the neck and includes a spline drive on one end and gearing on the opposite end. The spline drive is positioned adjacent the attachment opening in the neck. The cleaning member drive mechanism is matingly engaged with the gearing on the drive shaft, and the cleaning member extends through the cleaning member opening in the head and is operatively associated with the cleaning member drive mechanism. In use, motivating rotational force imparted to the spline drive is translated from the drive shaft to the cleaning member drive mechanism and to the cleaning member such that the cleaning member rotates. In a preferred embodiment, the spline drive includes a plurality of splines that each have an inclined surface on the distal end thereof. Preferably, each of the six splines includes two opposing longitudinally extending surfaces that taper toward the distal end. [0007] The invention, together with additional features and advantages thereof, may be best understood by reference to the following description. BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1 is a side elevational view of an electric toothbrush having a handle and brushing attachment removably connected to one another in accordance with a preferred embodiment of the present invention; [0009] FIG. 2 is an exploded view of the electric toothbrush of FIG. 1 , showing the drive hub and drive shaft; [0010] FIG. 3A is a perspective view of the drive shaft; [0011] FIG. 3B is a bottom plan view of the drive shaft; [0012] FIG. 4A is a perspective view of the drive hub; [0013] FIG. 4B is a top plan view of the drive hub; [0014] FIG. 4C is an cross-sectional view of the drive hub taken along line 4 C- 4 C of FIG. 4B ; [0015] FIG. 4D is an cross-sectional view of the drive hub taken along line 4 D- 4 D of FIG. 4C ; [0016] FIG. 5 is a side elevational view of the drive shaft inserted into the drive hub, with the drive hub shown in cross-section; [0017] FIG. 6 is a cross-sectional view taken along line 6 - 6 of FIG. 5 ; and [0018] FIG. 7 is a cross-sectional view of the brushing attachment with the internal components in elevation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0019] The following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, well-known or conventional details are not described in order to avoid obscuring the description. References to one or an embodiment in the present disclosure can be, but not necessarily are references to the same embodiment; and, such references mean at least one of the embodiments. [0020] Reference in this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the-disclosure. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but not other embodiments. [0021] The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Certain terms that are used to describe the disclosure are discussed below, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the disclosure. For convenience, certain terms may be highlighted, for example using italics and/or quotation marks: The use of highlighting has no influence on the scope and meaning of a term; the scope and meaning of a term is the same, in the same context, whether or not it is highlighted. It will be appreciated that the same thing can be said in more than one way. [0022] Consequently, alternative language and synonyms may be used for any one or more of the terms discussed herein. Nor is any special significance to be placed upon whether or not a term is elaborated or discussed herein. Synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and is not intended to further limit the scope and meaning of the disclosure or of any exemplified term. Likewise, the disclosure is not limited to various embodiments given in this specification. [0023] Without intent to further limit the scope of the disclosure, examples of instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions, will control. [0024] It will be appreciated that terms such as “front,” “back,” “upper,” “lower,” “side,” “short,” “long,” “up,” “down,” and “below” used herein are merely for ease of description and refer to the orientation of the components as shown in the figures. It should be understood that any orientation of the components described herein is within the scope of the present invention. [0025] Referring now to the drawings, which are for purposes of illustrating the present invention and not for purposes of limiting the same, FIGS. 1-6 show an electric toothbrush 10 having a handle 12 and a brushing attachment 14 and that includes a drive mechanism or interface 16 . It will be understood that the electrical components of the handle 12 , (e.g., the motor 17 , battery, etc.) and the components for transmitting motion (e.g., rotational motion) to the drive mechanism 16 are known. Therefore, a discussion of these components will be omitted. Furthermore, any type of attachment mechanism for securing the brushing attachment 14 to the handle 12 is within the scope of the present invention and, therefore, a description herein will be omitted. For example, the attachment mechanism taught in U.S. Pat. No. 8,196,246, the entirety of which is incorporated herein be reference, can be used. [0026] As shown in FIGS. 2 and 5 , the drive mechanism 16 generally includes a drive hub 18 that is received in a recess 20 defined in a brushing attachment connection receiver 22 that extends from the main body portion 21 of the handle 12 and a drive shaft 24 that is housed in a neck 26 of the brushing attachment 14 . A bushing can be used to position or secure drive shaft 24 within neck 26 . However, this is not a limitation on the present invention. [0027] With reference to FIGS. 2 and 7 , in a preferred embodiment, brushing attachment 14 includes a main body portion 25 (comprising neck 26 and a head 28 ) and cleaning member 30 (e.g., bristles). The neck 26 includes an attachment opening 26 a and the head 28 includes a cleaning member opening 28 a. It will be appreciated by those skilled in the art, that brushing attachment 14 can include brushing surfaces other than the bristles, such as massagers, flossers or other tooth cleaning technology known in the art (these are all referred to herein generally as “cleaning members”). Internally, the brushing attachment 14 includes gearing 32 or other energy translation mechanism for translating the rotational energy through the 90 degree bend from the drive shaft 24 to the cleaning member 30 . [0028] As shown in FIGS. 3A and 3B , in a preferred embodiment, drive shaft 24 is a unitary structure that includes a spline drive 34 comprising a series of splines 34 a on one end thereof, and gearing 32 on the other end thereof In another embodiment, the drive shaft 24 can be constructed of separate, non-unitary parts. As shown in FIG. 7 , the gearing 32 on the end of the drive shaft 24 mates with the gearing 32 on a cleaning member drive mechanism 33 that is positioned in the head 28 . Gearing for translating the rotation of the drive shaft 24 to the cleaning member drive mechanism 33 (through the 90 degree bend) and ultimately the cleaning member 30 is known. Any type of gearing or the like is within the scope of the present invention. Furthermore, any type of cleaning member drive mechanism 33 and attachment to the cleaning member 30 is within the scope of the present invention. [0029] As shown in FIGS. 4A-4D , in a preferred embodiment, drive hub 18 includes a main body portion 36 that is received in recess 20 , a rim 38 that seats on or is adjacent to the top surface of brushing attachment connection receiver 22 , a lower recess 40 for receiving rotational energy from the motor (e.g., via a knurled shaft), and an upper or grooved recess 42 that includes a series of grooves 44 that matingly engage the spline drive 34 of the drive shaft 24 . In a preferred embodiment, the grooves 44 each include a straight portion 44 a and a lead in or incline portion 44 b. The straight portion 44 a interfaces with the splines 34 a to provide the interface to facilitate the transfer of the rotational motivation generally from the handle 12 to the brushing attachment 14 , and more specifically, from the drive hub 18 to the drive shaft 24 . The incline portion 44 b helps facilitate the insertion of the spline drive 34 into the upper recess 42 . As shown in FIG. 4A , in a preferred embodiment, the incline portion 44 b of the grooves 44 includes a circumferential incline surface 46 a and two non-circumferential incline surfaces 46 b. [0030] The plurality of grooves 44 together form, within the upper recess 42 , a straight section 42 a and an incline section 42 b. As shown in FIGS. 4B and 6 , the incline section 42 b has a greater outer diameter OD 1 than the outer diameter of the spline drive 34 OD 2 (measured at the tip of the individual splines 34 a ) and a greater outer diameter OD 1 than the outer diameter of the straight section 42 a OD 3 . The larger diameter and incline section 42 b makes it easier to align the drive shaft 24 with the straight section 42 a of upper recess 42 when placing a brushing attachment 14 on the handle 12 . In a preferred embodiment, the splines 34 a each include an inclined surface 34 b on the distal end 34 c thereof, which further facilitates alignment of the drive shaft 24 and drive hub 18 . As is best shown in FIG. 5 , the splines 34 a each include two opposing longitudinally extending surfaces 34 d that taper toward the distal end 34 c thereof The inclined and tapered surfaces all help facilitate mating of the spline drive 34 with the grooved opening 42 of the drive hub 18 . In another embodiment, the tapered surfaces 34 d and the inclined surfaces 34 b can be omitted. [0031] In a preferred embodiment, as is shown best in FIG. 4B , within the series of grooves 44 , the drive hub 18 and upper recess 42 also include drive grooves 44 c and guide grooves 44 d. The guide grooves 44 d are sized larger than the splines 34 a and help provide proper alignment of the splines 34 a during attachment of the brushing attachment 14 . The clearance between the surfaces of splines 34 a and the inner surfaces of guide grooves 44 d are shown in FIG. 6 . The drive grooves 44 c are sized to snugly receive the splines 34 a and provide little clearance. In use, the drive surface of drive grooves 44 c contact the splines 34 a positioned within drive grooves 44 c to rotate drive shaft 24 . In a preferred embodiment, the drive grooves 44 c and the guide grooves 44 d alternate. However, this is not a limitation on the present invention. In the exemplary embodiment shown in the figures, the drive hub 18 includes three drive grooves 44 c and three guide grooves 44 d. However, this is not a limitation on the present invention and any number of drive grooves 44 c and guide grooves 44 d can be used. [0032] In use, a new brushing attachment 14 is placed onto the brushing attachment connection receiver 22 such that the spline drive 34 is received into upper recess 42 . As the spline drive 34 enters the incline section 42 b, if the drive shaft 24 is misaligned, as a result of the incline, the spline drive 34 will be guided inwardly until the axis of the drive shaft 24 is generally axial with the axis of the drive hub 18 and the spline drive 34 will enter the straight section 42 a of upper recess 42 . The individual splines 34 a each enter a corresponding drive groove 44 c or guide groove 44 d. The attachment mechanism between the handle 12 and brushing attachment 14 is attached and the toothbrush is now ready for use. When the toothbrush 10 is used, motivating rotational force is transferred from the motor to the drive hub 18 , which, as a result of the interaction of splines 34 a and drive grooves 44 c, imparts motivating rotational force to drive shaft 24 . As a result of gearing 32 , the motivating rotational force is translated 90 degrees from the drive shaft 24 and to cleaning member 30 , for teeth cleaning. [0033] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” As used herein, the terms “connected,” “coupled,” or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling of connection between the elements can be physical, logical, or a combination thereof Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description of the Preferred Embodiments using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. [0034] The above-detailed description of embodiments of the disclosure is not intended to be exhaustive or to limit the teachings to the precise form disclosed above. While specific embodiments of and examples for the disclosure are described above for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize. Further any specific numbers noted herein are only examples: alternative implementations may employ differing values or ranges. [0035] Any patents and applications and other references noted above, including any that may be listed in accompanying filing papers, are incorporated herein by reference in their entirety. Aspects of the disclosure can be modified, if necessary, to employ the systems, functions, and concepts of the various references described above to provide yet further embodiments of the disclosure. [0036] Accordingly, although exemplary embodiments of the invention have been shown and described, it is to be understood that all the terms used herein are descriptive rather than limiting, and that many changes, modifications, and substitutions may be made by one having ordinary skill in the art without departing from the spirit and scope of the invention.

A toothbrush that includes a brushing attachment and a handle. The brushing attachment includes a main body portion with a hollow neck having an attachment opening and a head with a cleaning member opening, a drive shaft positioned in the neck, a cleaning member drive mechanism matingly engaged with gearing on the drive shaft, and a cleaning member extending through the cleaning member opening in the head and operatively associated with the cleaning member drive mechanism. The drive shaft includes a spline drive on one end and gearing on the opposite end. The handle includes a main body portion with a brushing attachment connection receiver that is at least partially received in the attachment opening. The brushing attachment connection receiver includes a recess defined therein that receives a drive hub with a grooved recess defined therein that receives the spline drive.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the priority benefit of Taiwan application serial no. 94104990, filed on Feb. 21, 2005. All disclosure of the Taiwan application is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of Invention [0003] The present invention relates to a mobile storage device, more specifically, to a stackable mobile storage device. [0004] 2. Description of Related Art [0005] Nowadays is information and multi-media age, a vast amount of information is digitized before being processed. Large size magnetic disks were used in the past, however, affected by magnetization effect, so that the magnetic disks were gradually eliminated due to its insufficient capacity, and small storage memories with larger capacity. A smaller storage medium with larger storage capacity and smaller volume has been introduced instead. Memory card, mobile drive (or walk drive) and micro hard drive in most common use have been developed based on the flash memory technology. In addition, these new type drives have advantages of easy carrying and convenient access. [0006] Generally speaking, in the fabrication of the mobile drive, the mobile drive can mutually supports USB1.1 interface and USB2.0 interface to transport vast amount of data, so as to be compatible to a computer and its peripherals. And, the mobile drive requires no reading device (such as card reader), and features in plug-and-play. Moreover, since the capacity of the mobile drive is getting larger and larger, and it can store up to hundreds of compressed songs (such as MP3 music, etc.). Therefore, it can be very conveniently used as a walkman or pen recorder. [0007] Remarkably, the capacity of the conventional single mobile drive is fixed, and no extension slot is designed on the drive. Thus, it is impossible to expand the capacity of the mobile drive when the user finds that the capacity is insufficient. As a result, one has to partially delete or completely erase the data on the original mobile drive, or transfer the data to a computer hard drive, so that new data can be stored on the mobile drive. This is very inconvenient. If the size of the new data is larger than the capacity of the mobile drive, the user has to use an alternative method or purchase a drive with lager capacity to solve this issue. However this will increase the cost. Therefore, the conventional single-capacity mobile drive is not convenient in various uses, and the capacity of each mobile drive can't be shared, thus its usability is affected. SUMMARY OF THE INVENTION [0008] The object of the present invention is to provide a stackable mobile storage device which can expand the capacity of the mobile drive. [0009] Another object of the present invention is to provide a control circuit by which the capacity of each mobile drive can be aggregated into a larger capacity to store more data conveniently. [0010] The present invention provides a stackable mobile storage device including a first mobile drive, at least one second mobile drive and a detachable module. The first mobile drive includes a transmitting interface and a control unit, and the second mobile drive is stacked on the first mobile drive. Wherein, the first mobile drive has a first memory, while the second mobile drive has a second memory, and the capacity of the second memory can be added to the capacity of the first memory through a switching unit and is enabled by the control unit. In addition, the detachable module is coupled between the first and second mobile drives. [0011] The present invention provides a control circuit which is suitable for using in a mobile storage device with a plurality of mobile drives. Each of the mobile drives has a memory, a control unit, a detachable module and a switching unit. Wherein, the detachable module has a male connector and a female connector, and the mobile drives are electrically coupled to each others by a manner of the combination of the male and the female connectors. In addition, the switching unit has a first switch, a second switch and a third switch, wherein the first switch is coupled between the control unit and the memory, and the second switch is coupled between the male connector and the memory, and the third switch is coupled between the female connector and the memory, so that the memory of each mobile drive is enabled by the control unit. [0012] The present invention further provides a capacity expandable mobile drive which includes a base block, a transmitting interface, at least one connector and a switching unit. The base block includes a control unit and a memory, wherein the control unit is to control the reading and the writing operations on the memory. Moreover, the transmitting interface can be protruded out or hidden within the base block, and be electrically connected with the control unit. In addition, the connector is implemented on the base block to connect at least one second mobile drive which has a second memory. Furthermore, the switching unit has a plurality of switches wherein one of these switches is coupled between the control unit and the memory, and another one of these switches is coupled between the connector and the memory. As a result, the second memory of the second mobile drive can be enabled through the control unit. [0013] According to the embodiment of the present invention, the above control unit for example includes a control chip and a circuit board, and the control chip is electrically connected to a transmitting interface through the circuit board. In addition, the transmitting interface is, for example, a universal serial bus (USB) interface. Moreover, the switching unit is, for example, an electronic three-way switch or a mechanical three-way switch. [0014] The detachable module and the switching unit coupled between two mobile drives are used in the present invention to form a stackable mobile storage device with expandable capacity and its control circuit. Therefore, a single mobile drive can be used individually, and when a plurality of mobile drives are stacked together, the memories can be shared so as to increase the selectivity and manipulability of the mobile drive on using. [0015] These and other exemplary embodiments, features, aspects, and advantages of the present invention will be described and become more apparent from the detailed description of exemplary embodiments when reading in conjunction with accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0016] FIG. 1A - FIG. 1B schematically illustrate the outer appearance and internal block diagram of a stackable mobile storage device, according to an embodiment of the present invention. [0017] FIG. 2 schematically illustrates the block diagram of the internal equivalent circuit of the storage device of FIG. 1A . [0018] FIG. 3 and FIG. 4 respectively schematically illustrate the outer appearance and the block diagram of the internal equivalent circuit of a stackable mobile storage device, according to an embodiment of the present invention. [0019] FIG. 5 schematically illustrates the disassembling and assembling diagram of a stackable mobile storage device, according to another embodiment of the present invention. [0020] FIG. 6 schematically illustrates the block diagram of the internal equivalent circuit of the stackable flash storage device of FIG. 5 . DESCRIPTION OF THE PREFERRED EMBODIMENTS [0021] FIG. 1A - FIG. 1B schematically illustrate the outer appearance and internal block diagram of a stackable storage device, according to an embodiment of the present invention. And FIG. 2 schematically illustrates a block diagram of the internal equivalent circuit of the storage device of FIG. 1A . Referring to FIGS. 1A-1B , first, the stackable storage device 100 for example includes a base block 110 , a transmitting interface 120 , a male connector 132 , a female connector 134 and a switching unit 140 . Wherein, the base block 110 has a built-in control unit 112 , such as control a chip 114 , a circuit board 116 and the related parts thereof (not shown) etc. The control chip 114 can be electrically connected with the transmitting interface 120 through the circuit board 116 as shown in FIG. 1B . A usual transmitting interface 120 is, for example, a universal serial bus (USB) interface, an IEEE 1394 transmitting interface or other high speed transmitting interface, and preferably, the transmitting interface satisfying the specification of USB1.1 and USB2.0. In the present embodiment, although the transmitting interface 120 is protruded out of the base block 110 , it can also be a retractable design (not shown) within the base block 110 . The transmitting interface 120 can be electrically connected to the control unit 112 through a flat cable 136 , so that the transmitting interface 120 can be hidden in the base block 110 . [0022] With referring to FIG. 1B , the base block 110 further includes a memory 118 inside, which includes for example a flash memory or other types of high capacity storage medium, implemented on the circuit board 116 . The control chip 114 can access data on the memory 118 . Remarkably, the switching unit 140 is implemented on the circuit board 116 . In the equivalent circuit shown in FIG. 2 , a switching unit 140 including a plurality of switches 141 - 143 or a single three-way switch (shown in FIG. 1A ) is implemented between the control chip 114 and the memory 118 to switch the master/slave property of the storage device. When the storage device 100 is used individually, just by switching the switching unit 140 to the master connection end (close the switch 140 in the middle, and leave the upper and lower switches 141 and 143 open), the mobile drive can serve as a regular mobile drive. Moreover, to use a plurality of storage devices 100 , just by combining the male connector 132 and the female connector 134 for switching its storage device to slave connection end (leaving the switch 142 in the middle open, and closing the upper and lower switches 141 and 143 respectively), the mobile drive can then serve as an expanded mobile drive to expand the capacity of the memory 118 . [0023] With referring to FIG. 3 and FIG. 4 , both respectively show the diagram of the outer appearance and the block diagram of the internal equivalent circuit of a stackable mobile storage device of an embodiment of the present invention. The stackable mobile storage device 200 for example includes a first mobile drive 210 , at least one second mobile drive 220 and a detachable module 230 . The structure and function of the first mobile drive 210 are the same as those of the second mobile drive 220 . Inside the base block, 212 , 222 , both have control chips 214 , 224 and memories 216 and 226 , respectively. The difference is that when the first mobile drive 210 serves as the mobile drive of the master control end, the switch 218 in the middle is electrically coupled between the control chip 214 and the memory 216 , and leaves the circuit of upper and lower switches open. The second mobile drive 220 can only open the circuit of the middle and upper switches, and close the circuit of the lower switch 228 to connect the memory 226 and the corresponding female connector 234 , so that the second mobile drive serves as a mobile drive with an expanded capacity. In addition, the first and the second mobile drives 210 and 220 can be stacked on top of each other through a detachable module 230 that combines the male connector 232 to the female connector 234 . Specifically, the memory 226 of the second mobile drive 220 can be enabled by the control of the control chip 214 to store data. [0024] In the above embodiment, the transmitting interface (not shown) can be hidden within the base block 222 to avoid hindering the use of the transmitting interface 240 of the first mobile drive 210 when the second mobile drive 220 serves as the capacity expanding mobile drive. Moreover, if the second mobile drive 220 is used individually, the user can just conveniently set the transmitting interface (not shown) to protrude out of the base block 222 , thus enable the users to have various options of memory capacities without causing the insufficient memory problem. [0025] In addition, with referring to the FIG. 5 and FIG. 6 , both illustrate the diagram of the outer appearance and the internal equivalent circuit about a stackable mobile storage device, with an embodiment of the present invention. The stackable mobile storage device 300 for example includes a first mobile drive 210 , at least a second mobile drive 220 , at least a third mobile drive 320 and two detachable modules 230 and 330 . The structure and function of the first mobile drive 210 and the second mobile drive are as described in the previous embodiment, and there are also a control chip 324 and a memory 326 inside the base block 322 of the third mobile drive 320 . Specifically, when the first and the second mobile drive 210 , 220 are stacked on top of each other through a detachable module 230 between them, the first and the third mobile drives 210 and 320 can also be stacked on top of each other through another detachable module 330 (the combination of the male connector 332 and the female connector 334 ). In addition, the middle and the lower switches of the third mobile drive 320 are off, and the upper switch between the memory 326 and the corresponding male connector 332 is conducted, so that the whole of drive serves as a capacity expanding mobile drive, thus the mobile drive can be used very conveniently. [0026] Similarly, the memory 326 of the third mobile drive 320 can also be enabled through the control chip 214 in the first mobile drive 210 . Also and, the transmitting interface (not shown) can be hidden within the base block 322 to avoid hindering the use of the transmitting interface 240 in the first mobile drive 210 when the third mobile drive serves as a capacity expanding mobile drive. In addition, the transmitting interface (not shown) can be just protruded out of the base block 322 if the third mobile drive is used individually. The switch at the middle is conducted and the upper and lower switches are off. The reading and writing operations on the memory 326 are controlled by its own control unit 324 . [0027] It can be understood from the above descriptions, since a detachable module and a switching unit are used in the present invention to connect two mobile drives, a stackable mobile storage device and its control circuit with expandable memory capacity are formed. Wherein, each of the mobile drives is equipped with at least one connector (e.g. a male connector or a female connector, or both) which is capable of expanding the capacity of the memory, so that the capacity of the memory can be aggregated into a larger capacity. Moreover, the switching unit can be an electronic three-way switch, a mechanical three-way switch or a plurality of switches in combination. [0028] In summary, the stackable mobile storage device and the control unit thereof of the present invention have at least the advantages as follows: [0029] (1) Each mobile drive can be used individually, and a plurality of mobile drives can also be stacked on top of each other to share the memory to increase the selectivity and manipulability of the mobile drive. [0030] (2) The transmitting interface can be hidden within the base block to avoid hindering the use of the transmitting interface in the master control end of the mobile drive when the mobile drive serves as a capacity expanding mobile drive. [0031] While the present invention has been particularly shown and described with referring to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.

A stackable mobile storage device is provided, including a first mobile drive, at least a second mobile drive and a detachable module plugged between the first mobile drive and the second mobile drive to stack each other. The detachable module is composed of a male connector and a female connector. Especially, the second mobile drive is connected to a control unit of the first mobile drive by a switching unit when serving as a mobile drive for expanding capacity, to be enabled by the control of the first mobile drive. Therefore, the memory capacity of the second mobile drive can be added to the first mobile drive with more capacity to store more data.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims all benefits of Japanese Patent Application No. 2004-118856, filed on Apr. 14, 2004, in the Japanese Intellectual Property Office, and Korean Patent Application No. 2004-79209, filed on Oct. 5, 2004, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a memory medium, and, more particularly, to a method of recording and/or reproducing information with respect to a hologram memory medium, in which the information is recorded as interference fringes by using an object beam and a reference beam. [0004] 2. Related Art [0005] Recently, a rewritable optical disk of a phase shift type or an optical magnetic type is widely used as an information recording medium. In order to increase the recording density of such an optical disk, reducing the diameter of a beam spot and the distance between adjacent tracks or adjacent bits is required. [0006] Although the recording density of an optical disk has been increased, the recording density of such an optical disk is physically limited by a diffraction limit of a beam, because data is recorded on a surface. Accordingly, a three-dimensional multi-recording including a depth direction is required to increase the recording density of an optical disk. [0007] Therefore, a hologram memory medium having a large capacity due to a three-dimensional multi-recording region and a high speed due to a two-dimensional recording/reproducing method has attracted public attention as a next generation of computer file memory. Such a hologram memory medium may be formed by inserting a recording layer, which is formed of a photopolymer, between two sheets of glass. In order to record data on such a hologram memory medium, an object beam corresponding to data to be recorded and a reference beam are irradiated to the hologram memory medium to form interference fringes or interference patterns of the object beam and the reference beam. In order to reproduce data from the hologram memory medium, the reference beam is irradiated to the interference fringes to extract optical data corresponding to the recorded data. [0008] In addition, hologram memory media having a cube shape and a card shape are provided. For example, Japanese Laid-open Patent No. 2000-67204 discloses a card shaped hologram memory including multiple recording layers on which waveguides are recorded to increase a recording capacity. [0009] However, when recording/reproducing data on/from such a hologram memory medium, data is recorded on or reproduced from a data recording/reproducing area (or data area) on the hologram memory medium in a horizontal direction along a reference line, also known as a recording route, as shown in FIG. 1 . At the end of the reference line, the recording or the reproducing is stopped to move to an adjacent reference line, and then the recording or the reproducing of data is repeated in the horizontal direction along the adjacent reference line. However, such a method stops the recording or the reproducing of data at the ends of the reference lines. As a result, the operation continuity cannot be secured. Furthermore, the control of a data recording/reproducing optical system becomes complicated. SUMMARY OF THE INVENTION [0010] Accordingly, the present invention advantageously provides methods of recording/reproducing information on/from a hologram memory medium in which a recording/reproducing optical system can be conveniently controlled to increase a recording capacity of the hologram memory medium. [0011] According to an aspect of the present invention, a method of recording information on a card or rectangular shaped hologram memory medium, comprises sequentially recording information on a data recording/reproducing area of the card shaped hologram memory medium along a predetermined route, while maintaining a predetermined distance between stripes of information. [0012] Accordingly, the information can be continuously recorded on the card shaped hologram memory medium. In addition, the information can be continuously reproduced without operating an optical system, such as an optical pickup, unnecessarily. [0013] The predetermined route may be formed in a spiral shape that spans the entire data recording/reproducing area of the card shaped hologram memory medium. Since the predetermined route is formed in the spiral shape, the data recording/reproducing area of the card shaped hologram memory medium can be effectively used, and the information may be continuously recorded in the data recording/reproducing area of the card shaped hologram memory medium. [0014] The information recorded in the data recording/reproducing area of the card shaped hologram memory medium may be sequentially recorded from a central portion to a circumference or periphery of the card shaped hologram memory medium or from the circumference or periphery to the central portion of the card shaped hologram memory medium. [0015] Accordingly, the data recording/reproducing area of the card shaped hologram memory medium can be effectively used, while continuously recording the information without operating an optical system unnecessarily. [0016] Alternatively, the predetermined route may be formed in a continuous zig-zag shape that spans the entire data recording/reproducing area of the card shaped hologram memory medium, by having a plurality of reference lines that are parallel to one another and connecting the ends of each reference lines with the start portions of the following reference lines. [0017] The information recorded on the data recording/reproducing area of the card shaped hologram memory medium may be sequentially recorded from an opened end of a reference line to an opened end of another reference line. [0018] Accordingly, the data recording/reproducing area of the card shaped hologram memory medium can be effectively used, while continuously recording the information without operating an optical system unnecessarily. [0019] A recording shape adjacent to a portion of converting a recording direction is a curve. Accordingly, a servo following property of an optical system, such as an optical pickup, may be sufficiently secured even in a portion of converting the recording direction. [0020] According to an aspect of the present invention, the information may be recorded utilizing a two-dimensional shift multi-recording method. Accordingly, a recording capacity of the card-shaped hologram memory medium may be increased. When the information is recorded utilizing a two-dimensional shift multi-recording method, the distance between the parallel reference lines, which are formed in a spiral shape, is the same as a shift amount of the two-dimensional shift multi-recording. Accordingly, the information may be continuously recorded on the card shaped hologram memory medium, while increasing a recording capacity of the card shaped hologram memory medium, and without operating an optical system unnecessarily. [0021] The present invention is more specifically described in the following paragraphs by reference to the drawings attached only by way of example. BRIEF DESCRIPTION OF THE DRAWINGS [0022] A better understanding of the present invention will become apparent from the following detailed description of example embodiments and the claims when read in connection with the accompanying drawings, all forming a part of the disclosure of this invention. While the following written and illustrated disclosure focuses on disclosing example embodiments of the invention, it should be clearly understood that the same is by way of illustration and example only and that the invention is not limited thereto. The spirit and scope of the invention are limited only by the terms of the appended claims. The following represents brief descriptions of the drawings, wherein: [0023] FIG. 1 illustrates a conventional method of recording information on a hologram memory medium useful in gaining a more thorough appreciation of the present invention; [0024] FIG. 2 illustrates a method of recording/reproducing information on/from a data area of a card shaped hologram memory medium along a recording (reproducing) route in a spiral pattern according to a first embodiment of the present invention; [0025] FIG. 3 illustrates an adjacent distance according to the first embodiment of the present invention; [0026] FIG. 4 illustrates example interference fringes recorded in a spiral pattern according to the first embodiment of the present invention; [0027] FIG. 5 illustrates a method of recording/reproducing information on/from a data area of a card shaped hologram memory medium along a recording (reproducing) route in a continuous zig-zag pattern according to a second embodiment of the present invention; [0028] FIG. 6 illustrates an adjacent distance according to the second embodiment of the present invention; [0029] FIG. 7 illustrates example interference fringes according to the second embodiment of the present invention; [0030] FIG. 8 illustrates an example hologram memory medium according to an embodiment of the present invention; [0031] FIG. 9 is a block diagram of an example information recording/reproducing apparatus according to an embodiment of the present invention; [0032] FIG. 10 illustrates an example optical system according to an embodiment of the present invention; and [0033] FIG. 11 is a flowchart illustrating a method of recording/reproducing information on/from a hologram memory medium according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS [0034] The present invention is applicable for use with all types of memory or computer-readable media, hologram memory media, data recording/reproducing apparatuses and computer systems implemented methods described according to various embodiments of the present invention. However, for the sake of simplicity, discussions will concentrate mainly on exemplary use of a hologram memory media having a card shape or a rectangular shape, although the scope of the present invention is not limited thereto. [0035] Attention now is directed to the drawings and particularly to FIGS. 2 through 7 , in which hologram memory media having information recorded by methods of recording information such as video data, audio data, audio/visual (AV) data, computer files or meta information according to various embodiments of the present invention. Specifically, FIG. 2 illustrates a method of recording/reproducing information on/from a data area of a card shaped hologram memory medium along a recording (reproducing) route in a spiral or concentric pattern according to a first embodiment of the present invention. FIGS. 3-4 illustrate an example distance Ws between parallel reference lines established by an interference pattern which is a series of interference fringes that span the entire data area of the hologram memory medium, as shown in FIG. 2 . FIG. 5 illustrates another method of recording/reproducing information on/from a data area of a card shaped hologram memory medium along a recording (reproducing) route in a continuous zig-zag pattern according to a second embodiment of the present invention. FIGS. 6-7 illustrate an example distance Ws between parallel reference lines established by an interference pattern which is a series of interference fringes that span the entire data area of the hologram memory medium, as shown in FIG. 5 . FIG. 8 illustrates a sectional view of a hologram memory medium having servo information i.e., location determination information, recorded thereon which is arranged on a surface facing a surface having a data area. [0036] In one example embodiment of the present invention, an interference pattern which is a series of interference fringes recorded on the hologram memory medium is formed in a spiral shape, as shown in FIGS. 2 through 4 . Such interference fringes are recorded on the hologram memory medium due to an interference between an object beam and a reference beam during a recording operation. As a result, information can be continuously recorded on or reproduced from the hologram memory medium, starting from a central portion extending to a circumference or periphery of the hologram memory medium, or vice versa, without interruption, i.e., stopping recording or reproducing at an end of a reference line, and restarting at a next, adjacent reference line. In another example embodiment of the present invention, an interference pattern of interference fringes is formed in a continuous zig-zag shape by connecting end portions of reference lines to start portions of following references lines, while arranging the reference lines in parallel to one another, as shown in FIGS. 5 through 7 . [0037] Referring to FIG. 8 , a hologram memory medium 1 includes a substrate 2 , a hologram recording layer 3 , a total reflection layer 4 , a protective layer 5 , a coat layer (not shown), an adherence layer (not shown), and a substrate 6 having pits 7 in a concave shape or a convex shape. As shown in FIG. 8 , the substrates 2 and 6 serve as bases of the hologram memory medium 1 . The hologram recording layer 3 is formed of a photosensitive material, for example, a photo polymer, a photorefractive crystal or any other material having a high recording/reproducing efficiency and resolution. Such a material should allow for repeated recording and erasing of data without causing a deterioration of the high recording/reproducing efficiency and resolution characteristics. Information of an object beam is recorded as interference fringes on the hologram recording layer 3 by irradiating the object beam and a reference beam to the same location on the hologram memory medium 1 . [0038] The total reflection layer 4 reflects the object beam and the reference beam that are irradiated to the hologram recording layer 3 to prevent the transmission of the object beam and the reference beam to a surface facing a surface having a data recording/reproducing area. The protective layer 5 physically protects servo information, in other words, the pits 7 , in a concave shape or a convex shape formed on the substrate 6 from the outside. [0039] The pits 7 include servo information of an optical system, such as an optical pickup, which records or reproduces information. Accordingly, the servo information can be optically read from the substrate 6 of the hologram memory medium 1 so as to properly control the location of the optical system, i.e., the irradiation location of the object beam and the reference beam from the optical system. [0040] The pit row shape is symmetrical with the recording shape of the interference fringes (interference stripes), which are recorded on the hologram memory medium. For example, when the interference fringes are formed in a spiral shape, the pit row is formed in a spiral shape symmetrical with the spiral shape of the interference stripes. [0041] Referring to FIGS. 3 and 6 , the distance W S between the parallel reference lines is applied to a two-dimensional multi-recording method. Therefore, the distance W s may be the same as a shift amount of the two-dimensional multi-recording method. Accordingly, the distance between the pit rows is the same of the distance WS between the reference lines. The examples of the interference stripes, which are recorded by the two-dimensional shift multi-recording method, are shown in FIGS. 4 and 7 . [0042] In addition, recording information corresponding to table of content (TOC) data of a compact disk (CD) or a DVD is recorded in a predetermined location of the data recording/reproducing area. Such recording information recorded in the data recording/reproducing area includes location information, in other words, address data, recorded in each data row as well as actual recording information. Accordingly, an access to a predetermined data row can be performed by using the information corresponding to the TOC data and the address data of each data row. [0043] Turning now to FIG. 9 , an information recording/reproducing apparatus for recording/reproducing information on/from a hologram memory medium according to an embodiment of the present invention is illustrated. As shown in FIG. 9 , the information recording/reproducing apparatus includes a hologram memory medium transferring motor 10 , an optical pickup 11 , a feed motor 12 , a signal process integrated circuit (IC) 13 , a central processing unit (CPU) 14 , and a driver integrated circuit (IC) 15 . [0044] The hologram memory medium transferring motor 10 transfers a hologram memory medium 1 in a different direction from a reference line to the same distance as the shift amount of a shift multi-recording, at the end portion of the reference line. In addition, the transfer of the hologram memory medium transferring motor 10 is controlled by the output of the driver IC 15 . [0045] The optical pickup 11 includes optical elements such as a laser light source, for example, a semiconductor laser, a collimator lens, an object lens, which is driven by a focus actuator or a tracking actuator, and a polarizing beam splitter, and a light receiving device. [0046] The feed motor 12 moves the optical pickup 11 to a predetermined location along the hologram memory medium 1 . More specifically, in a search operation, the feed motor 12 controls the location of the optical pickup 11 by using a driving voltage supplied from the driver IC 15 . The driving voltage may be obtained, for example, based on the address data recorded on the hologram memory medium 1 . [0047] The signal process IC 13 generates a reproducing signal based on a return light quantity from the hologram memory medium 1 that is received by the light receiving device (not shown) in the optical pickup 11 , while generating a focus error (FE) signal obtained by detecting a focus error of a radiation laser from the optical pickup 11 by an astigmatism method based on the return light quantity obtained by the light receiving device (not shown) in the optical pickup 11 . Furthermore, the signal process IC 13 generates a track error (TE) signal obtained by detecting an error in the radiation laser from the optical pickup 11 in a reference line direction by a push-pull method. In addition, the signal process IC 13 generates a focus driving (FODRV) signal and a tracking driving (TRDRV) signal based on the FE and TE signals. [0048] The CPU 14 controls the information recording/reproducing apparatus based on a control program stored in an internal memory such as a read only memory (ROM). According to an embodiment of the present invention, the CPU 14 controls various servo operations when recording information on the hologram memory medium 1 . More specifically, the CPU 14 calculates a driving voltage of the feed motor 12 that is required to move the optical pickup 11 based on the present address data and the address data of a target location in a search operation, and supplies the driving voltage of the feed motor 12 to the driver IC 15 through the signal process IC 13 . [0049] The driver IC 15 inputs the focus driving (FODRV) signal or the tracking driving (TRDRV) signal that are generated in the signal process IC 13 , and amplifies the input focus driving (FODRV) signal or tracking driving (TRDRV) signal to a predetermined size. Thereafter, the driver IC 15 supplies the amplified signal to a focus actuator or a tracking actuator. [0050] Referring to FIG. 10 , an example optical system, such as an optical pickup 11 , shown in FIG. 9 , for use in an information recording/reproducing apparatus according to an embodiment of the present invention is illustrated. As shown in FIG. 10 , such an optical system includes a data recording/reproducing optical system 20 and a location determination controlling optical system 30 . The data recording/reproducing optical system 20 records information in the data recording/reproducing area of the hologram memory medium 1 and reproduces information from the data recording/reproducing area of the hologram memory medium 1 . The location determination controlling optical system 30 performs the location determination control of the object beam and the reference beam irradiated from the data recording/reproducing system 20 based on the servo information, when recording/reproducing information on/from the hologram memory medium 1 . In addition, the data recording/reproducing optical system 20 and the location determination controlling optical system 30 are integrally formed. In such a situation, the location determination controlling optical system 30 transfers inconnection with the transfer of the data recording/reproducing optical system 20 . However, the data recording/reproducing optical system 20 and the location determination controlling optical system 30 can also be physically separated. In such a situation, a control signal may be fed back from the location determination controlling optical system 30 to the data recording/reproducing optical system 20 so as to determine the location of the optical system. [0051] Turning now to FIG. 11 , a method of recording information on a hologram memory medium utilizing an information recording/reproducing apparatus according to an embodiment of the present invention will now be described as follows. [0052] When a hologram memory medium 1 is mounted in an information recording/reproducing apparatus in S 101 , a CPU 14 calculates a driving voltage of a feed motor 12 for transferring an optical pickup 11 based on address data from a location determination controlling optical system 30 in order to transfer the optical pickup 11 to a home position having recording information in the hologram memory medium 1 by supplying the driving voltage of the feed motor 12 to a driver IC 15 through a signal process IC 13 , in S 102 . [0053] Thereafter, the CPU 14 reads information corresponding to table of content (TOC) data, which is recorded around the home position, from a reproducing signal from the location determination controlling optical system 30 in order to determine whether the information is preliminarily recorded on the hologram memory medium 1 , in S 103 . In the case where the information is not recorded on the hologram memory medium 1 , the data recording/reproducing optical system 20 is transferred to a predetermined recording start location, in S 104 . [0054] In the case where the information is recorded on the hologram memory medium 1 , the data recording/reproducing optical system 20 is transferred to an address, which is obtained by shifting from the address of the last information by the amount corresponding to the shift amount of a shift multi-recording, in S 105 . When the recording/reproducing optical system 20 is transferred to a predetermined location, the data recording/reproducing optical system 20 radiates an object beam and a reference beam to the data recording/reproducing area of the hologram memory medium 1 to record predetermined information as interference stripes, in S 106 . Thereafter, the data recording/reproducing optical system 20 records information, while shifting by a predetermined amount based on location determination information, which is obtained from the location determination controlling optical system 30 . [0055] As described from the foregoing, the present invention advantageously provides methods of recording/reproducing information on/from a card type hologram memory medium, in which a data recording/reproducing area of the hologram memory medium can be effectively used, and information can be continuously recorded and reproduced. As a result, the operation continuity can be secured, and the control of a data recording/reproducing optical system can be simplified. In addition, such recording/reproducing methods can advantageously utilize two-dimensional shift multi-recording and reproducing techniques. [0056] While there have been illustrated and described what are considered to be example embodiments of the present invention, it will be understood by those skilled in the art and as technology develops that various changes and modification may be made, and equivalents may be substituted for elements thereof without departing from the spirit and scope of the present invention. Many modifications may be made to adapt the teachings of the present invention to a particular situation without departing from the scope thereof. For example, the hologram memory medium can be formed in different sizes and shapes, such as square, cube, spherical and elliptical shape, as long as information can be continuously recorded on or reproduced from the hologram memory medium without interruption. In addition, the hologram memory medium can be a recordable medium formed of a photo-polymer, a multi-waveguide type medium or a rewritable medium formed of photorefractive crystals, such as LiNbO 3 (lithium niobate). Similarly, the CPU can be implemented as a chipset having firmware, or alternatively, a general or special purposed computer programmed to perform the methods as described with reference to FIGS. 2-7 . Moreover, such a hologram memory medium can also have a wide range of applications, including multimedia computing, video-on demand, high-definition televisions, portable computing and consumer video. Accordingly, it is intended, therefore, that the present invention not be limited to the various example embodiments disclosed, but that the present invention includes all embodiments falling within the scope of the appended claims.

A method of recording/reproducing information on/from a card-shaped hologram memory medium is provided in which an information recording/reproducing optical system can be conveniently controlled to increase a recording capacity of the card-shaped hologram memory medium. In the method, pieces of information are sequentially recorded in a data recording/reproducing area of the card shaped hologram memory medium along a predetermined route, while maintaining a predetermined distance between pieces of information.

CROSS REFERENCE TO RELATED APPLICATIONS This application is the US National Stage of International Application No. PCT/EP2009/058092 filed Jun. 29, 2009, and claims the benefit thereof. The International Application claims the benefits of U.S. Provisional Application No. 61/172,262 US filed Apr. 24, 2009. All of the applications are incorporated by reference herein in their entirety. FIELD OF INVENTION The present invention generally relates to the field of determining equivalent mechanical loads of a component. In particular the present invention relates to a method for determining an equivalent mechanical load of a component of a machine, which component is subjected to a dynamic mechanical loading. Further, the present invention relates to a program element and to a computer-readable medium having stored a computer program, which, when being executed by a data processor, are adapted for controlling the equivalent mechanical load determining method. ART BACKGROUND At the present rainflow-counting and its variants are the most widely used methods in the analysis of fatigue data of mechanical components. The rainflow-counting method allows assessing the fatigue life of a structure subjected to a complex dynamic mechanical loading, the assessing being based on counting numbers of load half-cycles. The rainflow-counting method was originally developed in: Matsuiski, M. and Endo, T. Fatigue of metals subjected to varying stress, Japan Soc. Mech. Engineering (1969). A variant of the rainflow-counting method, as described in: Downing, S. D., Socie, D. F. (1982) Simple rainflow counting algorithms. International Journal of Fatigue , Volume 4, Issue 1, January, 31-40, is used for the fatigue analysis of wind turbine components. In order to apply the rainflow-counting method to the fatigue analysis of wind turbine components, measurements of component loads with a given sampling frequency are performed during the life-time of the wind turbine. Thereby, measurements of mechanical loads obtained in a response time, i.e., a predefined time period within the life-time of the turbine, for instance, a time period of 10 minutes are collected and used to obtain the time dependence of the mechanical load during the response time, the time dependence being represented by the corresponding discrete load curve, i.e. sample curve. The whole sample curve is used to determine the numbers of load half-cycles belonging to individual bins. This means that all measurements of mechanical loads performed during the response period are used. The numbers of load half-cycles belonging to individual bins occurring during the response time are then used to update count values of numbers of half-cycles belonging to individual bins occurring from a starting time of the counting. The starting time may be the time when the wind turbine has been brought into operation. Hence, the rainflow-counting method exhibits a severe drawback, which is inherent to the rainflow-counting method because when using this method, it is not possible to update the count values of numbers of half-cycles with each new sample, i.e., with each new load measurement. It may be an object of the present invention to provide an efficient and reliable mechanical load determination for a component, in particular for a component of a machine, which component is subjected to a dynamic mechanical loading. SUMMARY OF THE INVENTION In order to achieve the object defined above, a method for determining an equivalent mechanical load of a component, in particular of a component of a machine, which component is subjected to a dynamic mechanical loading according to the independent claim 1 is provided. According to a first aspect of the invention, a method for determining an equivalent mechanical load of a component, in particular of a component of a machine, which component is subjected to a dynamic mechanical loading is provided. The method comprises measuring a first measurement value of the mechanical load of the component and comparing the first measurement value with a first reference value. The method further comprises first updating at least one count value representing the number of load half-cycles of the component based on the result of comparing, wherein the load half-cycles correspond to a predetermined range of mechanical loads and occur within a time period prior to the measurement of the first measurement value. The method furthermore comprises determining a first equivalent mechanical load of the component based on the first updated count value. This aspect of the invention is based on the idea that an effective method for determining an equivalent mechanical load may be provided, if the equivalent load for the component can be updated when a load sample data for the component, such as one measurement value of the mechanical load, is obtained. Knowledge of the updated equivalent load value may be of great importance, since fatigue may occur if the component is subjected to a dynamic mechanical loading. The term “fatigue” may particularly denote any progressive and localized structural damage of the material of the component. The term “mechanical load” or simply “load” may particularly denote a moment of force, the force being acting, for instance, in one spatial direction and possibly exhibiting two different orientations. Hence, the mechanical load may, for instance, denote a one-dimensional vector quantity. This means the loads may take positive as well as negative values. Hence, the terms “increasing” and “decreasing” when used in relation to the load may refer to the load understood as a one-dimensional vector, rather then to the absolute value of the load. However, the method may also apply to two- or three-dimensional mechanical loads. The term “equivalent mechanical load” or simply “equivalent load” may in particular denote a mechanical load leading, during a given time period, to the same or equivalent fatigue of the material of the component as the actual load accumulated during the given time period. The term “dynamic mechanical loading” or simply “dynamic loading” may particularly denote a time sequence of loads of different sizes, orientations and durations, which sequence however may exhibit identifiable time periods of increasing loads and of decreasing loads. The term “increasing load half-cycle” or simply “increasing half-cycle” may particularly denote a mechanical loading during a period of an increasing mechanical load. The term “decreasing load half-cycle” or simply decreasing “half-cycle” may particularly denote a mechanical loading during a period of an decreasing mechanical load. The term “load half-cycle” or simply “half-cycle” may particularly denote a decreasing load half-cycle or an increasing load half-cycle. A load half-cycle may occur, for instance, between two adjacent local extremes of a curve representing the time dependence of the load respectively the load curve. However a load half-cycle may also occur between a starting value and a first local extreme or between a last local extreme and a last value of the load curve. The term “load half-cycle of a predetermined range of mechanical loads” may particularly denote a half-cycle, an increasing or a decreasing one, within which half-cycle the difference between its maximal load value and its minimal load value falls in the predetermined range of mechanical load values, the load values being positive. If, for instance, the predetermined range of mechanical load values is bounded from below by a lower bound then a half-cycle may fall within the predetermined range of mechanical load values, if difference of its maximal load value and its minimal load value is greater or equal to the lower bound. In this case, similarly, a load value, such as, for instance, a difference of the first measurement value and the first reference value may fall within the predetermined range of mechanical load values if it is greater or equal to the lower bound. Hence, according to this aspect of the invention an updating of the equivalent load is advantageously based on updating of the count value representing the number of load half-cycles of a predetermined range of mechanical loads. Such an updating may be performed each time when a measurement of the mechanical load has been performed. Hence, the method according to this invention may be advantageous because an online, i.e., based on an evaluation of each load sample data, monitoring of the component subjected to a dynamic mechanical load may be provided by the method. According to a further embodiment of the invention, the method further comprises updating the first reference value to a second reference value based on the result of comparing the first measurement value with the first reference value. The method furthermore comprises measuring a second measurement value of the mechanical load of the component and comparing the second measurement value with the second reference value. The method also comprises second updating the at least one count value representing the number of load half-cycles of the component based on the result of comparing the second measurement value with the second reference value, wherein the load half-cycles correspond to the predetermined range of mechanical loads and occur within a time period prior to the measurement of the second measurement value. Moreover, the method comprises determining a second updated equivalent mechanical load of the component based on the second updated count value. According to this embodiment due to the second updating of equivalent mechanical load the reliability and the effectiveness of the method may be increased. Hence, with a new load sample data the equivalent mechanical load may be immediately updated to a new value, which new value of the equivalent mechanical load may advantageously comprise information concerning the first as well as the second measurement value. As a result, the second updated count value may provide an accurate and reliable information concerning the fatigue of the material of the component at the time of the measuring the second measurement value. The time interval between the measurements of the first measurement value and the second measurement value may depend on a sampling frequency. The sampling frequency can be advantageously chosen such that and undersampling or an oversampling may be prevented. The sampling frequency may be chosen between 0.5 Hz and 25 Hz, particularly between 5 Hz and 15 Hz and even more particularly to 10 Hz. Such sampling frequency may ensure a good accuracy of the method when the component is, for instance, a base of a wind turbine or a blade root of a wind turbine. According to a further embodiment of the invention, first updating the at least one count value comprises increasing the at least one count value by one, if the first measurement value minus the first reference value is positive and falls within the predetermined range of mechanical loads or leaving the at least one count value unchanged, if the first measurement value minus the first reference value is positive and does not fall within the predetermined range of mechanical loads or if the first measurement value minus the first reference value is negative. Put in other words, the at least one count value will be increased if an increasing half-cycle in the predetermined range of mechanical loads is identified, which will be the case when the first measurement value minus the first reference value is positive and big enough to fall within the predetermined range of mechanical loads. If the first measurement value minus the first reference value is positive but is too small to fall within the predetermined range of mechanical loads, no half-cycle will be identified. Further, if the first measurement value minus the first reference value is negative, also no half-cycle will be identified independently of the size of the difference. Therefore, the at least one count value will not be changed even if a decreasing half-cycle in the predetermined range of mechanical loads could possibly have been identified. Hence, it can be said that, according to this embodiment, an increasing half-cycle in the predetermined range of mechanical loads may be identified. Accordingly, this embodiment may be referred to as being based on searching for an increasing half-cycle in the predetermined range of mechanical loads. According to a further embodiment of the invention, in case the at least one count value has been increased by one in course of the first updating, the second updating the at least one count value comprises further increasing the at least one count value by one, if the second reference value minus the second measurement value is positive and falls within the predetermined range of mechanical loads, or leaving the at least one count value unchanged, if the second reference value minus the second measurement value is positive and does not fall within the predetermined range of mechanical loads or if the second reference value minus the second measurement value is negative. In case the at least one count value has been left unchanged in course of the first updating, the second updating the at least one count value comprises increasing the at least one count value by one, if the second measurement value minus the second reference value is positive and falls within the predetermined range of mechanical loads, or further leaving the at least one count value unchanged, if the second measurement value minus the second reference value is positive and does not fall within the predetermined range of mechanical loads or if the second measurement value minus the second reference value is negative. Put in other words, if an increasing half-cycle has been identified based on the comparison of the first measurement value and the first reference value while searching for an increasing half-cycle in the predetermined range of mechanical loads, the at least one count value will again be increased if a decreasing half-cycle in the predetermined range of mechanical loads is identified as a next half-cycle. This will be the case when the second reference value minus the second measurement value is positive and big enough to fall within the predetermined range of mechanical loads. If the second reference value minus the second measurement value is positive but is too small to fall within the predetermined range of mechanical loads, no half-cycle will be identified. Further, if the second reference value minus the second measurement value is negative, also no half-cycle will be identified independently of the size of the difference. Therefore, the at least one count value will not be changed even if an increasing half-cycle in the predetermined range of mechanical loads could possibly have been identified. Hence, it can be said that, according to this embodiment, a decreasing half-cycle in the predetermined range of mechanical loads may be identified, following an identification of an increasing half-cycle in the predetermined range of mechanical loads. Also, according to this embodiment, if no increasing half-cycle has been identified based on the comparison of the first measurement value and the first reference value while searching for an increasing half-cycle in the predetermined range of mechanical loads, the search for an increasing half-cycle in the predetermined range of mechanical loads will continue. Hence, an increasing half-cycle in the predetermined range of mechanical loads may possibly be identified based on the comparison of the second measurement value and the second reference value and the at least one count value may be increased correspondingly. Therefore, advantageously, increasing half-cycles as well as decreasing half-cycles may be identified according to this embodiment, wherein searching for a decreasing half-cycle follows after an increasing half-cycle has been identified. According to a further embodiment of the invention, updating the first reference value to the second reference value comprises (a) setting the second reference value equal to the first measurement value, if the first measurement value minus the first reference value is positive and falls within the predetermined range of mechanical loads or if the first measurement value minus the first reference value is negative, or (b) setting the second reference value equal to the first reference value, if the first measurement value minus the first reference value is positive and does not fall within the predetermined range of mechanical loads. Because the identification of a half-cycle may be based on the comparison of a measurement value and a corresponding reference value, an updating of the first reference value, while searching for an increasing half-cycle, may be important for a proper identification of the half-cycle. According to this embodiment, the first reference value may be updated to the second reference value by setting the second reference equal to the first measurement value if an increasing half-cycle has been identified based on the comparison of the first measurement value and the first reference value while searching for an increasing half-cycle in the predetermined range of mechanical loads. Because the identification of the increasing half-cycle is followed by searching for a decreasing half-cycle in the same predetermined range of mechanical loads, the first measurement value can now be used as the second reference value in the subsequent searching for the decreasing half-cycle based on the comparison of the second measurement value and the second reference value. Also, according to this embodiment, the first reference value may alternatively be updated to the second reference value by setting the second reference equal to the first measurement value if the first measurement value minus the first reference value is negative and hence the first measurement value is indicating that, while searching for an increasing half-cycle in the predetermined range of mechanical loads, the load may actually be decreasing. In this case, the first measurement value can be used as the second reference value to continue in searching for the increasing half-cycle, now however based on the comparison of the second measurement value and the second reference value. Further, according to this embodiment, the first reference value may be updated to the second reference value by setting the second reference equal to the first reference value, i.e. the actual reference value will not be changed, if an increasing half-cycle has not been identified based on the comparison of the first measurement value and the first reference value while searching for an increasing half-cycle in the predetermined range of mechanical loads, but the load is an increasing one. In this case, the unchanged first reference value can be used as the second reference value to continue in searching for the increasing half-cycle, now however based on the comparison of the second measurement value and the second reference value. Hence, this embodiment may be described as referring to the updating of the first reference value to the second reference in course of searching for an increasing half-cycle in the predetermined range of mechanical loads. According to a further embodiment of the invention, first updating the at least one count value comprises (a) increasing the at least one count value by one, if the first reference value minus the first measurement value is positive and falls within the predetermined range of mechanical loads or (b) leaving the at least one count value unchanged, if the first reference value minus the first measurement value is positive and does not fall within the predetermined range of mechanical loads or if the first reference value minus the first measurement value is negative. Put in other words, the at least one count value will be increased if a decreasing half-cycle in the predetermined range of mechanical loads is identified, which will be the case when the first reference value minus the first measurement value is positive and big enough to fall within the predetermined range of mechanical loads. If the first reference value minus the first measurement value is positive but is too small to fall within the predetermined range of mechanical loads, no half-cycle will be identified. Further, if the first reference value minus the first measurement value is negative, also no half-cycle will be identified independently of the size of the difference. Therefore, the at least one count value will not be changed even if an increasing half-cycle in the predetermined range of mechanical loads could possibly have been identified. Hence, it can be said that, according to this embodiment, a decreasing half-cycle in the predetermined range of mechanical loads may be identified. Accordingly, this embodiment may be referred to as being based on searching for a decreasing half-cycle in the predetermined range of mechanical loads. According to a further embodiment of the invention, in case the at least one count value has been increased by one in course of the first updating, the second updating the at least one count value comprises (a) further increasing the at least one count value by one, if the second measurement value minus the second reference value is positive and falls within the predetermined range of mechanical loads, or (b) leaving the at least one count value unchanged, if the second measurement value minus the second reference value is positive and does not fall within the predetermined range of mechanical loads or if the second measurement value minus the second reference value is negative. Alternatively, in case the at least one count value has been left unchanged in course of the first updating, the second updating the at least one count value comprises (a) increasing the at least one count value by one, if the second reference value minus the second measurement value is positive and falls within the predetermined range of mechanical loads, or (b) further leaving the at least one count value unchanged, if the second reference value minus the second measurement value is positive and does not fall within the predetermined range of mechanical loads or if the second reference value minus the second measurement value is negative. Put in other words, if a decreasing half-cycle has been identified based on the comparison of the first measurement value and the first reference value while searching for an increasing half-cycle in the predetermined range of mechanical loads, the at least one count value will again be increased if an increasing half-cycle in the predetermined range of mechanical loads is identified as a next half-cycle. This will be the case when the second measurement value minus the second reference value is positive and big enough to fall within the predetermined range of mechanical loads. If the second measurement value minus the second reference value is positive but is too small to fall within the predetermined range of mechanical loads, no half-cycle will be identified. Further, if the second measurement value minus the second reference value is negative, also no half-cycle will be identified independently of the size of the difference. Therefore, the at least one count value will not be changed even if a decreasing half-cycle in the predetermined range of mechanical loads could possibly have been identified. Hence, it can be said that, according to this embodiment, an increasing half-cycle in the predetermined range of mechanical loads may be identified, following an identification of a decreasing half-cycle in the predetermined range of mechanical loads. Also, within this embodiment, if no decreasing half-cycle has been identified based on the comparison of the first measurement value and the first reference value while searching for a decreasing half-cycle in the predetermined range of mechanical loads, the search for a decreasing half-cycle in the predetermined range of mechanical loads will continue. Hence, a decreasing half-cycle in the predetermined range of mechanical loads may possibly be identified based on the comparison of the second measurement value and the second reference value and the at least one count value may be increased correspondingly. Therefore, advantageously increasing half-cycles as well as decreasing half-cycles may be identified according to this embodiment, wherein searching for an increasing half-cycle follows after a decreasing half-cycle has been identified. According to a further embodiment of the invention, updating the first reference value to the second reference value comprises (a) setting the second reference value equal to the first measurement value, if the first reference value minus the first measurement value is positive and falls within the predetermined range of mechanical loads or if the first reference value minus the first measurement value is negative, or (b) setting the second reference value equal to the first reference value, if the first reference value minus the first measurement value is positive and does not fall within the predetermined range of mechanical loads. Because the identification of a half-cycle is based on the comparison of a measurement value and a corresponding reference value, an updating of the first reference value, while searching for a decreasing half-cycle, may be important for a proper identification of the half-cycle. According to this embodiment, the first reference value may be updated to the second reference value by setting the second reference equal to the first measurement value if an decreasing half-cycle has been identified based on the comparison of the first measurement value and the first reference value while searching for a decreasing half-cycle in the predetermined range of mechanical loads. Because the identification of the decreasing half-cycle is followed by searching for an increasing half-cycle in the same predetermined range of mechanical loads, the first measurement value can now be used as the second reference value in the subsequent searching for the increasing half-cycle based on the comparison of the second measurement value and the second reference value. Also, according to this embodiment, the first reference value may alternatively be updated to the second reference value by setting the second reference equal to the first measurement value if the first reference value minus the first measurement value is negative and hence the first measurement value is indicating that, while searching for a decreasing half-cycle in the predetermined range of mechanical loads, the load may actually be increasing. In this case, the first measurement value can be used as the second reference value to continue in searching for the decreasing half-cycle, now however based on the comparison of the second measurement value and the second reference value. Further, according to this embodiment, the first reference value may be updated to the second reference value by setting the second reference equal to the first reference value, i.e. the actual reference value will not be changed, if a decreasing half-cycle has not been identified based on the comparison of the first measurement value and the first reference value while searching for a decreasing half-cycle in the predetermined range of mechanical loads, but the load is a decreasing one. In this case, the unchanged first reference value can be used as the second reference value to continue in searching for the decreasing half-cycle, now however based on the comparison of the second measurement value and the second reference value. Hence, this embodiment may be described as referring to the updating of the first reference value to the second reference in course of searching for a decreasing half-cycle in the predetermined range of mechanical loads. According to a further embodiment of the invention, at least one further count value is being associated with at least one further predetermined range of mechanical loads. The further predetermined range of mechanical loads comprises a lower bound which is higher than a lower bound of the predetermined range of mechanical loads. According to this embodiment, the method further comprises further comparing the first measurement value with a further first reference value and further first updating at least one further count value representing the number of further load half-cycles of the component based on the result of further comparing, wherein the further load half-cycles correspond to the further predetermined range of mechanical loads and occur within the time period prior to the measurement of the first measurement value. According to this embodiment, the method also comprises adapting the first updated count value. Determining the first equivalent mechanical load of the component is based on the adapted first updated count value and on the further first updated count value, according to this embodiment. Using further count values associated with further predetermined range of mechanical loads may increase the accuracy of the method. The predetermined range of mechanical loads and the further predetermined range of mechanical loads may also comprise a common upper bound. When the component is a base or a blade root of a wind turbine the number of predetermined ranges of loads may be chosen between 50 and 350, particularly between 100 and 300, more particularly between 150 and 250. The lower bounds of the neighboring ranges of loads may be separated for instance equidistantly, for example by a value of 1 kNm. However, separation of lower bounds of the neighboring ranges need not be equidistant. The properly chosen number of predetermined ranges may also ensure an effective real time numerical determining of the equivalent load. Further, according to this embodiment an overcounting of half-cycles may be prevented. The counting of cycles may be a cumulative counting. That means, that one half-cycle may be counted more times as a half-cycle corresponding to different ranges of loads. The overcounting caused by the cumulative character of the counting may be prevented by the adapting the first updated count value. According to a further embodiment of the invention, the adapting comprises decreasing the first updated count value by one, if the further first updating comprises increasing the at least one further count value and leaving the first updated count value unchanged, if the further first updating comprises leaving the at least one further count value unchanged. According to this embodiment, an overcounting of half-cycles may be prevented effectively. Since the counting of cycles may be a cumulative counting, an effective preventing of the overcounting may be advantageous to ensure the accurateness of the method. Hence, if one half-cycle has been be counted more times as a half-cycle corresponding to different ranges of loads, it will be counted only once as corresponding to the range of loads with the highest lower bound between the different ranges of loads, to which ranges of loads the half-cycle has been associated. According to a further embodiment of the invention, the method further comprises updating the further first reference value to a further second reference value based on the result of further comparing the first measurement value with the further first reference value. The described method also comprises further comparing the second measurement value with the further second reference value and further second updating the at least one further count value representing the number of further load half-cycles of the component based on the result of comparing the second measurement value with the further second reference value, wherein the further load half-cycles correspond to the further predetermined range of mechanical loads and occur within a time period prior to the measurement of the second measurement value. The described method furthermore comprises adapting the second updated count value. Determining the second updated equivalent mechanical load of the component is based on the adapted second updated count value and the further second updated count value, according to this embodiment. According to this embodiment, the accuracy and the effectiveness of the method may be increased, due to a proper combination of choices of the number of ranges of loads and the sampling frequency. The number of predetermined ranges of loads may be chosen between 50 and 350, particularly between 100 and 300, more particularly between 150 and 250 with lower bounds of the neighboring ranges of loads separated equidistantly, for instance, by a value of 1 kNm may be advantageously combined with sampling frequency chosen between 0.5 Hz and 25 Hz, particularly between 5 Hz and 15 Hz, more particularly to 10 Hz. These choices of the number of predetermined ranges and sampling frequency may also ensure an effective and stable real time numerical determining of the equivalent load. According to a further embodiment of the invention, adapting the second updated count value comprises decreasing the second updated count value by one, if the further second updating comprises increasing the at least one further count value and leaving the second updated count value unchanged, if the further second updating comprises leaving the at least one further count value unchanged. According to this embodiment an overcounting of half-cycles may be prevented effectively, when the number of ranges of loads is higher than 1. Since the counting of cycles may be a cumulative counting, preventing of an overcounting becomes more important, when the number of ranges of loads and/or the sampling frequency becomes higher. This may concern the numerical accuracy, effectiveness and/or stability of the method. Hence, if one half-cycle has been be counted more times as a half-cycle corresponding to different ranges of loads, it will be counted only once as corresponding to the range of loads with the highest lower bound between the different ranges of loads, to which ranges of loads the half-cycle has been associated. According to a further embodiment of the invention the method further comprises triggering a signal indicating the first updated equivalent load and/or the second updated equivalent load exceeding a preset threshold value. With the signal triggering an effective protection of the component and of the whole machine may be achieved. Exceeding of the threshold value may indicate that an overcritical fatigue of the material of the component may have been reached, and hence the structural changes and/or damages of the material of the component do not allow a safe and a reliable operation of the component and/or the machine anymore. Alternatively, the triggering of the signal may be based on a determination of a fatigue life consumption or a fatigue life consumption rate, which may be determined based on the determined equivalent mechanical load. In this case the signal may indicate that the fatigue life consumption or the fatigue life consumption exceeded a respective preset threshold value. In each case, based on the signal, the component may be exchanged and a further safe and reliable operation of the machine can be ensured. According to a further aspect of the invention, a program element for determining an equivalent mechanical load of a component is provided. The program element, when being executed by a data processor, is adapted for implementing the above described equivalent mechanical load determination method. The computer program element may be implemented as computer readable instruction code in any suitable programming language such as, for example, JAVA, C++, and may be stored on a computer-readable medium (removable disk, volatile or non-volatile memory, embedded memory/processor, etc.). The instruction code is operable to program a computer or other programmable device to carry out the intended functions. The computer program element may be stored on a computer-readable medium such as for example a removable disk, a volatile or non-volatile memory, or an embedded memory/processor. The computer program element may also be available from a network, such as the WorldWideWeb, from which it may be downloaded. According to a further aspect of the invention, a computer-readable medium on which there is stored a computer program for determining an equivalent mechanical load of a component is provided. The computer program, when being executed by a data processor, is adapted for implementing the method as set forth in any one of the preceding claims. The invention may be realized by means of a computer program element respectively software. However, the invention may also be realized by means of one or more specific electronic circuits respectively hardware. Furthermore, the invention may also be realized in a hybrid form, i.e. in a combination of software modules and hardware modules. It has to be noted that embodiments of the invention have been described with reference to different subject matters. In particular, one embodiment has been described with reference to an apparatus type claim whereas other embodiments have been described with reference to method type claims. However, a person skilled in the art will gather from the above and the following description that, unless other notified, in addition to any combination of features belonging to one type of subject matter also any combination between features relating to different subject matters, in particular between features of the apparatus type claim and features of the method type claims is considered as to be disclosed with this application. The aspects defined above and further aspects of the present invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to the examples of embodiment. The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a method for determining an equivalent load according to an exemplary embodiment of the invention. FIG. 2 illustrates a method for determining an equivalent load according to an exemplary embodiment of the invention on an example of a concrete load curve. DETAILED DESCRIPTION The illustrations in the drawings are schematical. FIG. 1 illustrates a method for determining an equivalent mechanical load according to an exemplary embodiment of the invention. The method concerns the determination of an equivalent mechanical load of a component, in particular of a component of a machine, the component being subjected to a dynamic mechanical loading. The machine can be, for instance, a wind turbine. The component can be, for instance a base of the wind turbine or a blade of the wind turbine, particularly a blade root of the wind turbine. In case of wind turbine components such as the base or the blade root, the mechanical load may be, for instance, the load along the direction of the wind. The method comprises counting the number of load half-cycles of the component. The load half-cycles may belong to one or more predetermined ranges of loads and may occur during an explicitly or implicitly predefined time interval. The time interval may be for instance the time interval starting at a time instant when the wind turbine and/or the corresponding wind turbine component has been brought into operation. For instance, the wind turbine and/or the corresponding wind turbine component has been for the first time exposed to a dynamic mechanical loading. The time period may end, for instance, at a time instant when a predetermined or estimated lifetime of the component or its fraction expires. The time period may also be not determined in advance, but may be chosen based on the determined equivalent load. For instance, the time period may end when a threshold value such as a critical value of the equivalent load is reached or exceeded. The counting the number of load half-cycles and/or the corresponding determining of the equivalent load may be performed online. This means that the respective values can be updated each time when a new sample data are available. An individual sample datum may correspond to a load value established in one measurement of the mechanical load. Hence, the sample data may be evaluated online for each new sample data during a given time interval of length T starting at an arbitrary but fixed time instant t=t 0 and ending at the time instant t 0 +T. The time interval may be given by the lifetime of the component, for instance, approximately 20 years for the wind turbine base or the wind turbine blade root, etc. Hence, counting the number of load half-cycles may also be referred to as an online half-cycle method or algorithm. In general the steps of the method may be described independently on a sampling frequency, i.e. on a number of measurements of loads within the given time interval of length T, once the sampling frequency has been chosen. The sampling frequency may be chosen depending on the concrete application, for instance, in a range between 0.5 Hz and 25 Hz, particularly between 5 Hz and 15 Hz, more particularly it can be chosen to be 10 Hz. The sampling frequency may be chosen such that an undersampling or an oversampling may be avoided. In a step S 0 , a fixed number n of ranges of loads is determined. Correspondingly, the same number of n bins and their sizes are determined. An expected or estimated range of the data signal r is calculated as the difference r=L max −L min between an expected or estimated maximal load L max value and an expected or estimated minimal load value L min within the time interval of length T. For example, the expected and/or estimated maximal and minimal load values can be based on or correspond to known critical load values for the component. For instance, the maximal load value L max may be chosen as a critical load value of the material of the component in a defined direction, i.e. an extreme load value causing a fatigue of the material of the component such that the further use of the component is not possible and the component has to be exchanged. In the technical field of wind turbines maximal load value L max may be chosen as the extreme load value of the component or the highest load allowed for normal operation. A monitoring system may be set up to issue an error message if the maximal load value L max will be exceeded, in which case the wind turbine may be stopped. Similarly the minimal load value L min may be chosen as the critical load value of the material of the component in the opposite direction. For instance, L min may be related to L max , if the component exhibits a particular symmetry. In particular, the absolute value of L max may be equal to the absolute value of −L min . In case of a wind turbine component, L max and L min may also be estimated based on estimated wind strengths in the defined direction. Based on the expected or estimated range of the data signal, the number of bins n is chosen such that an in advance fixed size of bins L 0 is matched. Alternatively, based on the expected and/or estimated range of the data signal, the size of bins L 0 is chosen such that an in advance fixed number of bins n is matched. Thereby, the size of the bins L 0 will be less or equal than the ratio r/n. Hence, the bins are all of size L 0 are numbered by integers 0, 1, 2, . . . , n−1, the i th bin being defined by an interval of loads [iL 0 ;(i+1)L 0 ]. Correspondingly, n ranges of loads are numbered by integers 0, 1, 2, . . . , n−1, the i th range of loads being [iL 0 ;r]. Although, for simplicity, these definitions will be used to illustrate this exemplary embodiment of the invention, alternative definition may be used as well. For instance, the i th range of loads may also be defined as being [(i+a)L 0 ;r] with a being from the interval [0,1), in particular [(i+½)L 0 ;r]. Also, the bins need not necessarily to be chosen of the same size and correspondingly the lower bounds of the ranges of loads need no be spaced equidistantly. The number of bins can be, depending on application, between 50 and 350, particularly between 100 and 350, more particularly between 150 and 250. However, the number of bins, their sizes and the corresponding ranges of loads need not to be determined or estimated, they all may be known in advance, e.g. from any previous load determining and/or monitoring of the same or similar mechanical components, in which case the step S 0 may be skipped. Hence, the step S 0 is optional. Next, the search for half-cycles corresponding to ranges of loads 0, 1, 2, . . . , n−1 is performed. The search for half-cycles corresponding to individual ranges of loads is performed independently and simultaneously. For simplicity, in the sequel the search will be described for one fixed but arbitrary range of loads i. This search is performed independently and simultaneously in two directions a positive one and a negative one. The search in the positive direction is described first in detail. The search in the positive direction starts by searching for a first increasing half-cycle corresponding to the range of loads i. As a starting reference value the load value L(0) at the time t=t 0 is chosen. According to the embodiment described here this starting reference value is common for all ranges of loads. The count value representing the number of load half-cycles of the component corresponding to the range of loads i is set to 0. Collection of all sample data, i.e., of all load measurements within the time interval of length T will define an a priori not known sample curve, i.e., a load curve representing the time dependency of the load, the sample data representing points of the sample curve. In a first step S 1 a first measurement value is obtained and compared to the starting condition, i.e., a first reference value L(0). Based on the comparison the count value 0 is updated. Depending on the comparison result the updated count value may remain to be unchanged, i.e., 0 or may be increased by 1, i.e., to take value 1. In a second step S 2 , based on the comparison, the reference value is updated. Depending on the comparison result the updated reference value, i.e., the second reference value may be equal to the first reference value L(0) or set to be equal to the first measurement value. Next, in the same step S 2 a second measured value is obtained and compared to the second reference value. Based on the second comparison the count value is updated. Depending on the comparison result the updated count value may remain to be unchanged or increased by one. Further steps S 3 , S 4 , . . . , Sm are performed in a complete analogy with the step S 2 . The number of steps m equals to the number of sample data, i.e., the number of load measurements in the given time interval of length T. As already mentioned, at each of the step S 1 , S 3 , . . . , Sm, the count values representing the number of load half-cycles corresponding to all predetermined ranges of loads 1, 2, . . . , n may be updated. In case when the number n of the predetermined ranges of loads is higher than 1, if a half-cycle corresponding to the range of loads numbered by i, for i being greater than 1, is identified, the same half-cycle may be identified at the same step or may have been identified at one of earlier steps as a half-cycle corresponding to a range of loads numbered by any of numbers lesser than i. Therefore, at each of the steps S 1 , S 3 , . . . , Sm, if the count value corresponding to the range of loads numbered by i, for i being greater than 1, is increased by 1, in addition each of the count values corresponding to ranges of loads numbered by 0, 1, 2, . . . , i−1 will be decreased by 1 in order to prevent an overcounting of half-cycles. The adapted count values obtained that way may be interpreted as representing numbers of half-cycles belonging to individual bins and may be used in order to determine the equivalent loads at each of the steps S 1 , S 3 , . . . , Sm. In the steps S 1 , S 2 , . . . , Sm, the following recursive rules are applied for updating the count value corresponding to the predetermined range of loads and the reference value. Following online the sample data, i.e., moving, with each new measurement value obtained, step by step, along the a priori unknown load curve from the time t=t 0 and the starting reference value L(0), i.e. from a starting reference point (t 0 ;L(0)), a new reference value L(1) will be chosen, i.e., the reference value will be updated to L(1) not equal to L(0), in two cases, whichever case occurs first: a1) one arrives at a point (t 1 ;L(1)) on the load curve in which the measurement value L(1) is lesser than the reference value L(0), or b1) one arrives at a point (t 1 ;L(1)) on the load curve in which the measurement value L(1) is greater than the reference value L(0) with the difference L(1)−L(0) greater or equal to iL 0 , the lower bound of the range of loads i. In the case a1) one continues in the subsequent step in searching for the first increasing half-cycle corresponding to the range of loads i, however using the new lesser reference value L(1). In the case b1) one not only updates the reference value to a greater value L(1) but one also counts one half-cycle, in this case the first half-cycle, corresponding to the range of loads i. Also, since this half-cycle has obviously been also counted as one of half-cycles corresponding to ranges of loads 0, 1, . . . , i−1, one reduces the number of counts of all half-cycles corresponding to the ranges of loads 0, 1, . . . , i−1 by one in order to prevent an over-counting of half-cycles. From this point, in the subsequent step or steps, one continues the search in the positive direction by searching for a first decreasing half-cycle corresponding to the range of loads i, i.e. a second half-cycle corresponding to the range of loads i, using the greater value L(1) as the new reference value. While searching for the first decreasing half-cycle corresponding to the range of loads i in the positive direction in the subsequent step or steps, moving along the sample curve from the time t 1 and the updated reference value L(1), i.e. from the reference point (t 1 ;L(1)), a new reference value L(2) will be chosen, i.e., the reference value will be updated to L(2) not equal to L(1), again in two cases, whichever case occurs first: a2) one arrives at a point (t 2 ;L(2)) on the load curve in which the measurement value L(2) is greater than the reference value L(1), or b2) one arrives at a point (t 2 ;L(2)) on the load curve in which the measurement value L(2) is smaller than the reference value L(1) but with the difference L(1)−L(2) equal or greater to the range of loads iL 0 , the lower bound of the range of loads i. In the case a2) one continues in the subsequent step in searching for the first decreasing half-cycle of range i, however using the new reference value L(2). In the case b2) one not only updates the reference value to L(2) but one also counts one half-cycle, in this case the second half-cycle, of range i. Also, since this half-cycle has obviously been also counted as one of half-cycles corresponding to ranges of loads 0, 1, . . . , i−1, one reduces the number of counts of all half-cycles corresponding to the ranges of loads 0, 1, . . . , i−1 by one in order to prevent an over-counting of half-cycles. From this point, in the subsequent step or steps, one continues the search in the positive direction by searching for a second increasing half-cycle corresponding to range of loads i, i.e. a third half-cycle corresponding to range of loads i, using the lesser value L(2) as the new reference value. According to the embodiment described here this search is completely analogous to the searching for the first increasing half-cycle corresponding to range of loads i and is followed by searching for a second decreasing half-cycle of range i, i.e. the fourth half-cycle corresponding to range of loads i in a complete analogy with the searching for the first decreasing half-cycle of range i. The process continues until the last point of the load curve at the time instant t 0 +T is reached. According to the embodiment described here the independent and simultaneous search in the negative direction is analogous to the search in the positive direction. The only difference is that now a search for a first decreasing half-cycle, instead of the first increasing half-cycle, corresponding to range of loads i is performed starting from the starting reference value L(0). After the first decreasing half-cycle corresponding to range of loads i has been identified, a search for the first increasing half-cycle, instead of the first decreasing half cycle, corresponding to the range of loads i is performed and so forth. At each of the steps S 1 , S 3 , . . . , Sm, one value of the equivalent load is determined for the positive search and the second value of the equivalent load is determined for the negative search. The equivalent load at each of the steps is determined to be the greater one of these to values. Although, the method for determining an equivalent mechanical load of a component was illustrated in relation to an online evaluation of measurement values, the method can be used equally well also in the case when the load curve in the given interval is known a priori. Also, the method for determining an equivalent mechanical load of a component has been described in relation to ranges of loads. However, because of the relation between the ranges of loads and the intervals of loads corresponding to the bins, the method may unambiguously be also described and understood in relation to bins. Further, dynamic bin administration optionally accompanying the method for determining an equivalent mechanical load according to an exemplary embodiment of the invention will be described. The dynamic bin administration may be used when an a priori estimation of the range of data signal may be problematic and there may be some possibility that the expected and/or estimated range of data signal may be exceeded by an actual range of data signal at some time instant during the load monitoring. The dynamic bin size administration is optional and may run in parallel to and independently on the counting the number of load half-cycles, when the counting the number of load half-cycles is performed on an online sample data. The dynamic bin size administration checks, with each new measurement, the range of the data signal, i.e., the difference of the absolute maximum and the absolute minimum, within the time interval between the starting time t 0 and a time t when a new measurement has been performed, i.e., the time of the new sample. For simplicity, it is assumed that the number of bins n, which is an arbitrary but fixed natural number is chosen to be even. The dynamic bin size administration can be easily modified for n being odd. If the range of the data signal in the time interval between 0 and t for a current time t exceeds the upper bound nL 0 of the interval of loads corresponding to the bin numbered as n−1, the following updates are carried out: 1. The size of bins L 0 is doubled; i.e., updated to 2L 0 . Hence, the new bin of number i, for i from 0 to n/2−1 contains now the two old bins of numbers 2i and 2i+1. 2. The lower bound of the interval of loads corresponding to the bin number i is updated to 2iL 0 . 3. The upper bound of the interval of loads corresponding to the bin number i is updated to 2(i+1)L 0 . 4. The numbers of half-cycles belonging to individual bins are updated correspondingly to point 1. The new count of half-cycles belonging to the new bin number i, for i between 0 and n/2−1, is the sum of half-cycle counts belonging to the old bins numbers 2i and 2i+1. 5. The reference value of the new bin number i, for i between 0 and n/2−1, is updated to be the reference value of the old bin of number 2i. 6. If at time t a search for an increasing/decreasing half-cycle belonging to the old bin number 2i was performed, a search for an increasing/decreasing half-cycle belonging to the new bin number i, for i between 0 and n/2−1, will be performed from the time t. However, at the time t a search for an increasing/decreasing half-cycle belonging to the old bin number 2i may have been performed while a simultaneous search for an decreasing/increasing half-cycle belonging to the old bin number 2i+1 may have been performed. Therefore, optionally, counts of half-cycles belonging to individual bins in addition to being updated according to above point 4 may also be increased by 1. 7. For new bin of numbers i, for i between n/2 and n−1: counts are set to zero, reference values are taken to be the reference value the old bin of number n and, at the point a search is started for an increasing half-cycle in the positive direction and for a decreasing half-cycle in the negative direction. For simplicity, the above updates have been described in relation to the intervals of loads corresponding to bins. However, because of the relation between the ranges of loads and the intervals of loads corresponding to the bins, these updates may be unambiguously also understood in relation to the ranges of loads. The above procedure will be repeated again when the range of the data signal within a time interval between the time instant t 0 and some new time instant t′ will exceeded the new upper bound n2L 0 of the interval of loads corresponding to the new bin numbered by n−1. Although the dynamic bin administration has been described in an example, when the size of new bins is doubled with respect to the size of old bins, any ratio greater than one of the size of new bins and the size of old bins is possible. Of course all other updates performed in course of the dynamic bin administration. FIG. 2 illustrates the method for determining an equivalent load according to an exemplary embodiment of the invention on an example of a concrete load curve. The method will be described on the example of a concrete, although only illustrative, load curve 100 shown in FIG. 2 . For simplicity, an idealized situation of a continuous load curve will be described, that means that the sampling rate approaches infinity and that at each time instant a new measurement value is available. The load curve 100 represents schematically the time dependence during a time period of length T of the tower base load, i.e. moment along the wind direction. The physical unit used for the vertical axis is kNm (kNewton meters). However, the mechanical load may be also measured indirectly, in which case for example a measurement of acceleration of at least a part of the component, which is related to a force acting on it, which force is in turn related to a stress and/or a strain to which the component is subjected. Alternatively also a displacement of at least a part of the component can be performed and used as a load signal. Hence, also other physical units, for instance acceleration unit ms −2 (meter per squared second) or displacement unit m (meter) may be used for the vertical axis as well. For simplicity, the units of the load will not be explicitly specified in the sequel. The range of the data signal is defined by the difference between the absolute maximum at point P 3 and the absolute minimum at the point P 4 of the load curve. There are 8 ranges of loads and 8 bins. The bins are of size 1 and both ranges of loads and bins are numbered from 0 to 7. The searching for half-cycles in the positive direction will be described on examples of half-cycles corresponding to the ranges of loads 1 and 4. Since it is assumed that there is no undersampling, at each sampling step the number of half-cycles corresponding to the ranges of loads 1 and 4 is the same as the number of half-cycles belonging to bins numbered as 1 and 4. Searching for half-cycles corresponding to ranges of loads 0, 2, 3, 5, 6 and 7, is completely analogous. The value of the load at the time t=0 is taken to be zero for simplicity. The zero value of the load defines a starting reference value and the corresponding point (0;0) of the load curve defines a starting reference point. The search in the positive direction of half-cycles corresponding to the range of loads 1 starts at the starting reference point (0;0) searching for a first increasing half-cycle. As we move along the curve 100 starting from the reference point (0;0) we do not change the reference value as long as the load curve 100 takes values greater than the reference value 0 but lower than the load value 1. In the example of FIG. 1 , the curve 100 takes values greater than 0 and lesser than 1 at each time instance in the time interval between t=0 and t=t 1 and reaches the load value 1 at the point A 1 =(t 1 ;1), at which point the difference between the load value at this point and the reference value 0 at t=0 is 1, corresponding to the number 1 of the range of loads. Therefore, as one is moving along the curve from the starting reference point, reference value will remain to be 0 all the way until the point A 1 is reached. At this point the reference value is changed to 1 and the first increasing half-cycle 101 corresponding to the range of loads 1 is identified. At the time t 1 one starts to search for a first decreasing half-cycle corresponding to the range of loads 1, i.e., a second half-cycle corresponding to the range of loads 1 in positive direction. Starting from the point A 1 the load curve 100 is an increasing one until it reaches at the time instant t 2 the point P 1 =(t 2 ;2.3). Therefore, as one is now searching for a decreasing half-cycle in the positive direction, the reference value will be changed to the corresponding load value at each time instant in the interval between t 1 and t 2 as one moves along the curve 100 from the point A 1 until one arrives at the time t 2 at the point P 1 . Hence, at the time t 2 , the load value 2.3 is the reference value. The point P 1 is a turning point of the load curve 100 and the load curve 100 starts to decrease from this point. From that point one will not change the reference value until the load value remains lower than the reference value 2.3 and remains greater than 1.3, i.e., greater than the difference between the reference value 2.3 and 1, the value 1 corresponding to the number 1 of the range of loads. In the example of FIG. 2 , the load curve 100 takes values lesser than 2.3 and greater than 1.3 at each time instant in the time interval between t 2 and t 3 and at time t 3 the load curve 100 reaches the point B 1 =(t 3 ;1.3). The difference between the load values at times t=t 1 and t=0 is 1. Therefore, the reference value 2.3 remains to be unchanged until one arrives at the point B 1 . At this point the reference value is changed to 1.3 and the first decreasing half-cycle 102 corresponding to the range of loads 1 has is identified. At the time t 3 one starts to search for a second increasing half-cycle corresponding to the range of loads 1, i.e., a third half-cycle corresponding to the range of loads 1 in the positive direction. Starting from the point B 1 the load curve 100 is a decreasing one until it reaches at the time instant t 4 point P 2 =(t 4 ;0.2). Therefore, as one is searching for an increasing half-cycle in the positive direction, the reference value will be changed at each time instant in the interval between t 3 and t 4 as one moves along the curve 100 from the point B 1 until one arrives at the time t 4 at the point P 2 . Hence, at the time t 4 , the load value 0.2 is the reference value. The point P 2 is a turning point of the curve 100 and the curve starts to increase from this point. From that point one will not change the reference value until the load value remains greater than the reference value 0.2 and lesser than 1.2, i.e., lesser than the sum of the reference value 0.2 and 1, the value 1 corresponding to the range of loads 1. In the example of FIG. 2 , the load curve 100 takes values greater than 0.2 and smaller than 1.2 at each time instance in the time interval between t 4 and t 5 and at time t 5 the load curve reaches the point C 1 =(t 5 ;1.2). Therefore, the reference value 0.2 remains unchanged until one arrives at the point C 1 . At this point the reference value is changed to 1.2 and the second increasing half-cycle 103 corresponding to the range of loads 1 is identified. At the time t 5 one starts to search for a second decreasing half-cycle corresponding to the range of loads 1 in the positive direction, i.e., a fourth half-cycle corresponding to the range of loads 1 in the positive direction. The process is completely analogous to the one described above with respect to the first decreasing half-cycle 102 corresponding to the range of loads 1. The second decreasing half-cycle 104 corresponding to the range of loads 1 is identified at the point D 1 corresponding to the time t 8 . At the time t 8 one starts to search for a third increasing half-cycle corresponding to the range of loads 1 in the positive direction of, i.e., a fifth half-cycle corresponding to the range of loads 1 in the positive direction. The process is completely analogous to the one described above with respect to the first 101 and second increasing half-cycle 103 corresponding to the range of loads 1. The third decreasing half-cycle 105 corresponding to the range of loads 1 is identified at the point E 1 corresponding to the time t 11 . From the above description it is clear, that the five half-cycles 101 to 105 corresponding to range of loads 1 counted above at the points A 1 , B 1 , C 1 , D 1 and E 1 , respectively are all half-cycles corresponding to range of loads 1 of the sample curve 100 . Following the same method as above for half-cycles corresponding to the range of loads 4 in the positive direction one ends up with one increasing half-cycle 401 corresponding to the range of loads 4 at the point A 4 and one decreasing half-cycle 402 corresponding to the range of loads 4 at the point B 4 , i.e., one ends up with two half-cycles corresponding to the range of loads 4 in the positive direction. However, one should notice that one has an over-count of half-cycles. It is clear that the half-cycle 401 corresponding to the range of loads 4 identified at the point A 4 has also been identified at the point C 1 as a half-cycle corresponding to the range of loads 1. Similarly the half-cycle 402 corresponding to the range of loads 4 identified at the point B 4 has also been identified at the point D. This means that the counts produced by the method are accumulated counts. Therefore, if a half-cycle which does not correspond to the range of loads 1 is identified in the positive or in the negative direction the count value of all half-cycles corresponding to the ranges of loads numbered by smaller numbers counted in the respective direction is lowered by one. In the example of curve 100 also the importance of both directions, the positive and the negative one, can be illustrated. If the search had been performed only in the positive direction a half-cycle corresponding to the range of loads 7, between points P 3 and P 7 would not have been identified. If n i is the determined number half-cycles belonging to the bin number I and L i is the load characterizing the bin i, for instance, the lower bound of the interval of loads corresponding to the bin i, which is the same as the lower bound of the range of loads i then the equivalent mechanical load may be computed using the formula L eqv =(Σ i n i ( L i ) m ) 1/m where m is the Wohler slope and the sum is taken over all bins, i.e., all ranges of loads. The Wohler slope depends on the component and it may be chosen, for instance, to be 3.5 in case of the base of the wind turbine and 15 in case of the blade root of the turbine. However, depending on a concrete application, the Wohler slope can be chosen also differently. In applications the equivalent mechanical load L egv may also be calculated based on full cycles instead of half-cycles, in which case the sum in the above formula has to be divided by 2. The method for determining an equivalent mechanical load of a component can also be used for an online monitoring of gearbox pitting and rupture fatigue loads. In this case the determination of the equivalent mechanical load may be based on duration counts of tooth engagements. The method can also be easily modified for monitoring of pitch bearing activity, in which case counting of cycles corresponding to predetermined ranges of angles travelled and/or loads will be performed. Hence, measuring of angles and/or measuring of loads maybe performed in course of the monitoring of pitch bearing activity. It should be noted that the term “comprising” does not exclude other elements or steps and “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims. LIST OF REFERENCE SIGNS 100 load curve 101 first increasing half-cycle corresponding to the range of loads 1 in the positive direction 102 first decreasing half-cycle corresponding to the range of loads 1 in the positive direction 103 second increasing half-cycle corresponding to the range of loads 1 in the positive direction 104 second decreasing half-cycle corresponding to the range of loads 1 in the positive direction 105 third increasing half-cycle corresponding to the range of loads 1 in the positive direction 401 first increasing half-cycle corresponding to the range of loads 4 in the positive direction 402 first decreasing half-cycle corresponding to the range of loads 4 in the positive direction

A method for determining an equivalent mechanical load of a component includes a dynamic mechanical loading. A first measurement value of the mechanical load of the component is measured and compared to a first reference value. Further, at least one count value representing the number of load half-cycles of the component is updated based upon the result of comparing, wherein the load half-cycles correspond to a predetermined range of mechanical loads and occur within a time period prior to the measurement of the first measurement value. A first equivalent mechanical load of the component is determined based on the first updated count value. It is further described a program element and a computer-readable medium having stored a program for controlling the described equivalent mechanical load determining method.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 13/548,899 filed on Jul. 13, 2012, which is a continuation of U.S. patent application Ser. No. 12/487,489 filed Jun. 18, 2009, the entirety of which are incorporated herein by reference. BACKGROUND [0002] Lacerations and other wounds which compromise the integrity of the skin are common enough that most people have experienced them, from the mundane, such as a skinned knee, to the life-threatening, such as a stab wound or a serious burn. Many breaks to the skin raise the possibility of disfigurement through scarring. [0003] The development of scar tissue is a defensive response to an injury in that it repairs a breach in the skin, eliminating a site of potential infection and reinjury. However, the rampant formation of scar tissue can result in a tough dermal surface lacking the color or consistency of the surrounding skin. Because the flexibility and elasticity of scar tissue differs from that of natural skin, scar tissue can ultimately limit the lives of those who are affected. Scar tissue is generally tougher than the skin tissue in the surrounding area. This is especially true of scar tissue where the skin is subjected to deformation and elastic stresses, such as on or behind the knee or elbow. Such areas can be subject to tear at the skin/scar tissue border. Scar tissue, particularly new scars, covering areas having natural grooves to facilitate bending, such as the lines on the palms of the hands, are often weak at these flex lines. Stretching caused by opening and closing the hand can rupture the scar tissue at these natural grooves, resulting in an accumulation of scar tissue on either side of the groove, causing newly formed tissue in the groove even to have even greater susceptibility to tearing with hand motion. In general, the natural topography of a wound site can increase the likelihood of retearing, resulting in long healing times. [0004] The lack of flexibility and suppleness of scar tissue is complicated by the fact that scarred areas can become naturally contracted during and after formation as the scar becomes thick, leathery, and inelastic. As a result, the motion of those who have extensive skin injury, such as burn victims, can be severely restricted. A severely burned hand can become frozen in a grasp. Scar tissue due to burns around the waist can prevent torsional motions that most people take for granted. [0005] Some preparations for treating wounds are formulated to have a positive effect on the properties of the scar tissue formed during healing. For example, some wound dressings have functions such as reducing wound drying and preventing ultraviolet light exposure. Such formulations can prevent repeated cracking and drying, resulting in, among other things, the formation of scar tissue having improved flexibility, elasticity and color characteristics relative to scar tissue formed in the absence of the formulation. [0006] Some formulations are made of strictly organic materials, such as gels. Gels have properties which make them suitable as wound dressings. They can cool wounds by contacting them directly, yet keep them free from contamination. Another useful property of gels is their consistency: many gels are similar to skin in elasticity and deformability, and they can bend, bunch and stretch with the skin and tissue surfaces to which they are attached without causing tearing or stress at the site of the healing wound. [0007] However, gels can dry out rapidly with time, break down structurally and/or chemically, and they generally must be reapplied, which can be a painful process for the patient, especially if the consistency of the dressing has become stiff due to drying. Some gels can absorb moisture, developing a soft or liquid consistency. Once the gel consistency has been compromised, the potential for bacterial infection increases. [0008] Siloxane gels have been found to be generally superior to other types of gel products in the treatment of wounds and scar tissue. Siloxane gels function by forming a silicone-based polymer matrix over a wound site. Polymer precursors, such as dimethicone, dimethicone crosspolymer, and other siloxanes, are contained in a spreadable preparation which is applied to a wound site. Some polymer precursor formulations include fumed silica. The preparation also contains a volatile component which begins to evaporate upon the application of the preparation to a wound site. The polymer matrix begins to form upon the evaporation of volatile compounds from the spreadable preparation. The preparations are, in many cases, thixotropic, particularly if the formulation contains fumed silica. Thixotropic formulations change from a stiff consistency to a fluid-like consistency upon the application of stress, such as application to a wound, and revert to a stiffer, less fluid consistency once the stress is removed. This property gives siloxane gel precursor formulations the ability to spread easily into a relatively thin layer over a wound and remain in place without oozing away from the wound site, all with a minimum of stress and shear at the wound site. [0009] Another advantage of siloxane gels is that some have been shown to have a beneficial effect on the properties of scar tissue as it is being formed, diminishing the degree of scarring and improving the texture of scar tissue that does form, such that the ultimate appearance of the healed wound is more like surrounding skin. For instance, some siloxane preparations, when applied to developing or newly formed scar tissue, have demonstrated the ability to cause excellent fading, and even near disappearance of the scar with constant application. [0010] Unlike other spreadable preparations on the market for aiding in the healing of wounds, once a degree of polymerization has taken place to form the siloxane polymer matrix, the resultant gel generally has the ability to retain its consistency over time. Furthermore, the unapplied product can be easier to store and use than other types of gels because it can be applied as siloxane polymer matrix precursors which do not “set” until after application. [0011] Because siloxane gels have such beneficial effects upon developing scar tissue, it is desirable that such a preparation also have the ability to include additives which impart additional useful functions to the gel. For example, while the foregoing silicone-based formulations demonstrate superior scar reduction properties, developing scar tissue is susceptible to change in color and/or texture, as well as other types of damage, such as thermal damage, upon exposure to ultraviolet and other wavelengths of radiation. It is thus desirable to incorporate sun screening compounds into the formulation which will be retained upon matrix formation. Furthermore, burns and other injuries which are best served by the topical application of gels can continue to be very painful, even after the wound has begun to scar over. However, the application of the matrix forming preparation can prevent the topical application of pain relievers: unlike bandage-type coverings, most topical gels cannot be simply lifted and resituated. It can thus desirable that matrix forming preparations comprise at least one pain alleviating compound. [0012] Unfortunately, the use of siloxane matrix precursors has severely limited the variety of additives which can be included in silicone wound dressings. Many desirable additives are not readily solvated in the mix of matrix precursors, such as dimethicone and other siloxanes which comprise the spreadable preparation. For example, many effective and commonly used sunscreen additives, such as, for example, Octocrylene, Octinoxate, Octisalate and Oxybenzone may not sufficiently dissolve in the pre-polymerized preparation. Other examples of desirable additives having poor solubility in the pre-polymerization preparation include cortisone-type compounds which reduce pain and inflammation, such as, for example, Hydrocortisone acetate. [0013] A method exploiting the advantages of siloxane matrix-forming wound preparations, yet allowing the inclusion of otherwise insoluble additives in silicone wound dressing formulations would be welcomed as a significant advance in the art of wound dressing preparation. BRIEF DESCRIPTION OF THE INVENTION [0014] It has been found, surprisingly, that the use of certain volatile coagents (in addition to the volatile component) with certain actives, which are otherwise of limited or no solubility in the matrix precursors, enables the incorporation of the actives into a silicone matrix. This is all the more surprising in that the complex which enables the incorporation of the active into the forming matrix actually retains a good degree of volatility, even though complexed with the active, and even though it would be expected that the developing matrix would hinder the ability of the complexed coagent to evaporate. Surprisingly, the volatile coagent is not incorporated within the matrix with the active. Instead, the insoluble active, which is insoluble in the matrix precursors without the coagent, remains incorporated within the matrix during its formation, even though the volatile coagent does not remain complexed to the active, but disjoins and is lost to evaporation. Even more surprising, the active can have mobility within the matrix resulting in the ability to migrate through the gel to the wound site, as evidenced by the effectiveness of analgesic additives. Furthermore, it would be expected that the vapor pressure of the volatile coagent would be reduced upon complexing with the active, and by being incorporated, with the active, within the developing siloxane matrix. Yet it retains sufficient vapor pressure such that it can evaporate away cleanly. The use of volatile coagents, such as those identified herein, permits the incorporation of diverse additive types into silicone matrix-forming formulations. The present invention enables the incorporation of insoluble actives into a mixture of silicon precursors, greatly extending the usefulness of siloxane gel wound healing technology. DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 —Drying test results. The lowest, middle and highest curves graphically depict the drying results of the sunscreen, analgesic and control gels respectively. DETAILED DESCRIPTION OF THE INVENTION Siloxane Matrix Precursors [0016] The matrix forming composition of the present invention comprises siloxane matrix precursors, a volatile component, an active component, and a volatile coagent. The volatile component and volatile coagent partially or fully evaporate from the composition once the composition is applied to a wound or scar site, leaving behind 1) components which participate in matrix formation as well as 2) one or more active components which reside in the matrix. Generally, the components which participate in the matrix formation are one or more siloxanes, one or more of which have organic characteristics, i.e., comprising organic components, such as bearing hydrocarbyl groups. Preferred are polydimethylsiloxanes such as dimethicone and dimethicone cross polymer. A polymer matrix can be formed with the use of other polydimethyl siloxanes instead of or in addition to dimethicone and dimethicone crosspolymer. In particular, it is believed that polymerization involving other polysiloxanes, and in particular, other dialkylpolysiloxanes, can form a matrix exhibiting the advantages of the present invention when used with the volatile components, volatile coagents and actives listed below. Such matrices are within the ambit of the present invention. The fumed silica gives the prepolymerized composition a thixotropic consistency. Fumed silica also participates structurally in the gel, but its contribution to or participation in the polymerization process, if any, is unclear. Provided that a volatile component is present, the matrix precursors in the preparation generally can be stored at room temperature (25 K) for extended periods of time, such as 1, 2, 4, 6, 12 months or even longer without undergoing significant polymerization. It is preferred that the matrix precursors comprise a crosspolymer component, such as dimethicone crosspolymer, as well as dimethicone. In some embodiments, the siloxane component is present in weight percentages in the range of from about 25 to 60 wt %. In preferred embodiments, the siloxane component is present in the range of from 30 to 50 wt %. In more preferred embodiments, the siloxane component is present in amounts in the range of from about 35 to 45 wt %. The preferred siloxane component is dimethicone. The cross polymer component is preferably present in amounts in the range of from about 0.5 to about 8 wt %, and more preferably in the range of from about 1.5 to 5 wt %. Volatile Component [0017] The composition of the present invention comprises a volatile component (distinguished from volatile coagent, discussed below). The volatile component generally begins to vaporize upon application of the composition to the wound site. In some embodiments, the formation of the siloxane matrix can begin immediately upon commencement of evaporation, proceeding with further evaporation. In other embodiments, the siloxane matrix begins to form appreciably at some time during the evaporation of the volatile component, with only negligible formation prior to the time. In preferred embodiments, the volatile component has limited or no participation in polymerization, but readily solvates or dissolves in the matrix precursors. Preferred examples are volatile siloxane compounds which have little or no participation as reactants in siloxane polymerization. For example, cyclic siloxanes generally exhibit good solvation and volatility characteristics in siloxanes, and their participation in matrix formation is generally relatively low due to the fact that all silane oxygen atoms are unavailable for polymerization. More preferred is a cyclopentasiloxane which bears constituents comprising hydrogen or hydrocarbyl groups of less than four carbon atoms. Constituents comprising hydrogen or hydrocarbyl groups of one carbon atom are most preferred. Preferred amounts of volatile component are in the range of from about 12 to about 45 wt %. More preferred are amounts in the range of from about 15 to 28 wt %, most preferred are amounts in the range of from about 20 to 25 wt %. [0018] The volatile component is preferably present in amounts such that the volatile component is more than 50 percent evaporated after 15 minutes at one or more temperatures in the range of from about 30 to 40 C. [0019] In general, the volatile component functions such that upon its partial or entire evaporation, the polymer matrix begins to form. Thus, in some embodiments, the presence of the volatile can act to fully or partially inhibit the polymerization process, such that upon beginning to volatilize, the rate of polymerization increases. In general, the composition of the present invention is not limited to the compounds specifically described above, but broadly comprises compounds which can be used in relative amounts such that they fully or partially inhibit the formation of the siloxane matrix prior to wound application, but begin to evaporate upon the application of the preparation to a wound, having fully or partially evaporated by the completion of siloxane matrix formation. In some embodiments, the volatile component evaporation plateaus with time prior to complete evaporation. In other embodiments, the evaporation of the volatile component continues after the siloxane matrix is completely formed. It is preferable that the volatile component evaporate to within less than 5% of its original weight (storage concentration) within 3 hours, but in some embodiments, the volatile evaporates to within greater than 10, 20 and 30% of its original weight within 3 hours. In some embodiments, the weight percent of the volatile component concentration prior to use and during storage is in the range of from about 5 to about 40%. In other embodiments, the weight percent of the volatile component concentration prior to use and during storage is in the range of from about 15 to about 35%, In preferred embodiments, the volatile component concentration prior to use and during storage is in the range of from about 18 to about 30%. Actives and Volatile Coagent [0020] The wound healing preparation of the present invention comprises a volatile coagent. Without desiring to be bound by theory, it is thought that the volatile coagent aids in solvating the active in the matrix precursors. It has been found that certain compounds which function as volatile coagents with certain actives have the ability to volatilize appreciably despite the facts that they are chemically associated with the active which is surrounded by a growing matrix, and which itself is not ultimately volatilized. [0021] Many common ultraviolet absorbers are not readily soluble in solutions comprising siloxane matrix precursors. However, it has been found that many ultraviolet absorbers can be solvated in siloxane matrix precursor solutions in the presence of myristate esters. For example, well known Escalol ultraviolet absorbers, having the following diverse structures can be introduced into siloxane matrices: Octocrylene (ISP Escalol 597): [0022] Octinoxate (ISP Escalol 557): [0023] Octisalate (ISP Escalol 587): [0024] Oxybenzone (ISP Escalol 567): [0025] [0026] In one embodiment, the active is an ultraviolet absorbing compound comprising at least one aromatic ring. In a more preferred embodiment the active comprises one or more Escalol compounds, available from ISP Chemicals, and the volatile coagent is an ester of 1) a linear acid having a carbon chain length in the range of from about 6 to 13 carbon atoms and 2) methanol, ethanol, or a secondary alcohol having a total carbon content in the range of from about 3 to about 8 carbon atoms. In a more preferred embodiment, the volatile coagent is a myristate ester of methanol, ethanol, or a secondary alcohol having a total carbon content in the range of from about 3 to about 8 carbon atoms, and the active is an Escalol compound. In a yet more preferred embodiment, the volatile coagent is isopropyl myristate, and the active is Octocrylene (ISP Escalol 597), Octinoxate (ISP Escalol 557), Octisalate (ISP Escalol 587), or Oxybenzone (ISP Escalol 567). The sunscreen active or actives present in the formulation can be present in a combined amount in the range of from about 5 to 40 wt %, with amounts in the range of from 15 to 35 wt % being more preferable. In some embodiments, the sunscreen actives are present in amounts in the range of from 25 to 30 wt %. [0027] In general, the volatile coagent preferably comprises an ester of 1) a linear acid having a carbon chain length in the range of from about 6 to 13 carbon atoms and 2) methanol, ethanol, or a secondary alcohol having a total carbon content in the range of from about 3 to about 8 carbon atoms; and more preferably isopropyl myristate; a glycol comprised of a linear chain of three or more carbons and one or more hydroxyl groups; and wherein all hydroxyl groups are on adjacent carbons including an end carbon; and more preferably pentylene glycol; or a substituted or unsubstituted isosorbide; and preferably Dimethyl isosorbide. [0028] Many common anti-inflammatory compounds are based on the steroid compound structure. It has been found that some steroids having low solubility in solutions of siloxane matrix precursors can be solvated in siloxane matrix precursor solutions in the presence of glycol and/or isosorbide compounds. [0029] In one embodiment, the active is a steroid compound, and the volatile coagent is a glycol comprised of a linear chain of three or more carbons and one or more hydroxyl groups; and wherein all hydroxyl groups are on adjacent carbons including an end carbon. In a more preferred embodiment, the volatile coagent is a glycol comprised of a linear chain of from about 3 to 7 carbons and two hydroxyl groups, one attached to each terminal carbon, and the active is a steroid compound. In a yet more preferred embodiment, the volatile coagent is pentylene glycol, and the active is dihydrocortisone acetate. [0030] In one embodiment, the active is a steroid compound, and the volatile coagent comprises a substituted or unsubstituted isosorbide. In a more preferred embodiment, the active is a cortisone, and the volatile coagent comprises a disubstituted isosorbide. In a yet more preferred embodiment, the volatile coagent is dimethyl isosorbide and the active is dihydrocortisone acetate. [0031] In one embodiment, the active is a hydrocortisone compound and actives comprising both a glycol compound and an isosorbide compound are used. In a preferred compound, the active is Hydrocortisone acetate. [0032] The steroid compound is preferably present in an amount which is in the range of from 0.1 to 8 wt %. More preferred is an amount in the range of from about 0.5 to 3 wt %. [0033] The glycol and the isosorbide are present in amounts in the range of from 5 to 40 wt % percent (combined weight, if both are present). In preferred embodiments, both are present, each in amounts in the range of from 5 to 50 wt %. In other embodiments, the glycol and the isosorbide are present in amounts in the range of from 0 to 15 wt %, with a total weight % in the range of from 10 to 25. [0034] It should be noted that the glycol and isosorbide components can be used with sunscreen actives instead of isopropyl myristate if a deeper penetration is desired. [0035] The composition of the present invention can be prepared by mixing together the matrix precursors such as, for example, fumed silica, dimethicone and dimethicone cross polymer; and the volatile component, such as, for example, cyclopentasiloxane. The foregoing compounds can be mixed together to form a siloxane base. The active component is generally mixed with the volatile coagent to form a mixture which is added to the siloxane base before introducing it into the balance of the composition. In one embodiment, the base contains only cyclopentasiloxane and dimethicone crosspolymer. The mixture is then combined with the base. In general, it is desirable to premix the active with the volatile coagent. However, in some cases, it can be permissible to combine the volatile coagent with all ingredients except the active, adding the active to the preparation in a final step. EXAMPLE 1 30 SPF Sunscreen Scar Gel [0036] Scar Gel with 10.0% Octocrylene, 7.5% Octinoxate, 5.0% Octisalate, 6.0% Oxybenzone, 8.0% isopropyl myristate, 36% dimethicone, 3.5% fumed silica, 2% dimethicone crosspolymer and 22% cyclopentasiloxane. All percentages wt/wt. Octocrylene, Octinoxate, Octisalate and Oxybenzone provide UVA and UVB resistance. They were premixed with isopropyl myristate. The mixture was added to a combination of cyclopentasiloxane and dimethicone crosspolymer. Fumed silica was added next to the overall mixture using a high-shear mixing process (an eductor). The dimethicone is added last, and the mixture is mixed until homogeneous, resulting in a viscous, opaque gel, with no lumps or visible separation. The formulation has an SPF rating of 30 or higher. A drying test was performed (time take to reach a constant weight) (see FIG. 1 ), and the formulation dried in essentially the same amount of time as the formulation in the absence of the Octocrylene, Octinoxate, Octisalate, Oxybenzone and isopropyl myristate (control formulation). The addition of the sunscreen additives does not appreciably slow the drying of the formulation. EXAMPLE 2 Hydrocortisone Acetate Scar Gel [0037] Scar Gel with 1.0% hydrocortisone acetate, 5.0% propylene glycol, 8.0% dimethyl isosorbide, 12.0% pentylene glycol, 45.0% dimethicone, 3.0% fumed silica, 2.0% dimethicone crosspolymer, and 24.0% cyclopentasiloxane. All percentages are wt/wt. The hydrocortisone acetate was pre-mixed into the pentylene glycol, dimethyl isosorbide and propylene glycol and warmed slightly to obtain good mixing before adding to a main batch. The main batch was prepared using a high-shear mixing apparatus (an eductor). No lumps or visible particles were observed. The resulting batch was uniform and slightly opaque. A drying test was performed (see FIG. 1 ), and the formulation dried in essentially the same amount of time as the formulation in the absence of the dihydrocortisone acetate, propylene glycol and dimethyl isosorbide (control formulation). The addition of the pain/itch reliever does not appreciably slow the drying of the formulation. EXAMPLE 3 Experimental Details of the Drying Tests “30 SPF Sunscreen Silicone Scar Gel” Details [0038] The “30 SPF Sunscreen Silicone Scar Gel,” described in Example 1, above, contains the ingredients of the Control Formula Scar Gel” with the addition of the following FDA approved sunscreen actives: 10.0% Octocrylene, 7.5% Octinoxate, 5.0% Octisalate and 6.0% Oxybenzone. Also, 8.0% of Isopropyl Myristate, an emollient ester, was added as a dispersing agent. “1% Hydrocortisone Acetate Silicone Scar Gel” Details [0039] The “1% Hydrocortisone Acetate Silicone Scar Gel,” described in Example 2, above, contains the ingredients of the Control Formula Scar Gel” with the addition of 1% w/w of Hydrocortisone Acetate, an FDA approved anti-inflammatory agent. Also, 5.0% of Propylene Glycol (a humectant and skin conditioning agent) and 10.0% of Dimethyl Isosorbide, a solvent which is a dimethyl ether of an anhydride of an isomer of sorbitol, used for better skin penetration of the Hydrocortisone Acetate. Procedure: [0040] The 30 plastic weigh boats were labeled and accurately weighed on an O'Haus EP114 analytical balance. Samples of the Control Formula Scar Gel” were spread out in a thin film on ten plastic weigh boats and the initial weights recorded (T=0). The samples were placed into the Lunaire Environmental Chamber set at 35° C. then removed and weighed at 5, 10, 40, 60, 180, 240, 300 and 1440 minute intervals. The process was repeated for the “30 SPF Sunscreen Silicone Scar Gel” and the “1% Hydrocortisone Acetate Silicone Scar Gel”. The results of the comparative study are listed below in TABLE 1—Control Formula Scar Gel Evaporation Study Results; TABLE 2—30 SPF Sunscreen Silicone Gel Evaporation Study Results and TABLE 3—1% Hydrocortisone acetate Silicone Gel Evaporation Study Results. The data from each table has been tabulated and displayed graphically in FIG. 1 . Equipment Used: [0000] (30) 5.25″×3.50″×1.0″ plastic weigh boats (1) Calibrated O'Haus EP114 Explorer Pro analytical balance (1) Lunaire Environmental Chamber Model #GEO932M-4 set at 35° C. Results [0044] [0000] TABLE 1 Control Formula Scar Gel Evaporation Study Results Empty Weigh Weight at Weight at Weight at Weight at Weight at Weight at Weight at Weight at Weight at Boat T = 0 T = 5 T = 10 T = 40 T = 60 T = 180 T = 240 T = 300 T = 1440 (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) KCG Sample 1 3.1621 3.3948 3.3888 3.3863 3.3786 3.3723 3.2731 3.2722 3.2722 3.2715 KCG Sample 2 3.2660 3.3410 3.3385 3.3358 3.3286 3.3278 3.3075 3.3052 3.3031 3.3015 KCG Sample 3 3.5625 3.6590 3.6570 3.6555 3.6472 3.6430 3.6074 3.6067 3.6067 3.6067 KCG Sample 4 3.4816 3.5715 3.5669 3.5621 3.5523 3.5500 3.5213 3.5200 3.5198 3.5201 KCG Sample 5 3.5648 3.6670 3.6596 3.6549 3.6450 3.6412 3.6140 3.6140 3.6132 3.6121 KCG Sample 6 3.5218 3.6102 3.6050 3.5910 3.5660 3.5630 3.5600 3.5599 3.5558 3.5558 KCG Sample 7 3.3741 3.4565 3.4500 3.4459 3.4308 3.4244 3.4101 3.4099 3.4098 3.4098 KCG Sample 8 3.4364 3.4865 3.4849 3.4828 3.4738 3.4688 3.4585 3.4580 3.4583 3.4568 KCG Sample 9 3.4109 3.4724 3.4698 3.4684 3.4585 3.4547 3.4391 3.4383 3.4382 3.4383 KCG Sample 10 3.4674 3.5153 3.5137 3.5113 3.5032 3.4953 3.4903 3.4888 3.4889 3.4888 Note: “T” equals the time interval, in minutes, at which the weights were determined. [0000] TABLE 2 30 SPF Sunscreen Silicone Scar Gel Evaporation Study Results Empty Weigh Weight at Weight at Weight at Weight at Weight at Weight at Weight at Weight at Weight at Boat T = 0 T = 5 T = 10 T = 40 T = 60 T = 180 T = 240 T = 300 T = 1440 (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) SSG Sample 1 3.3015 3.4060 3.4032 3.4035 3.3963 3.3931 3.3799 3.3799 3.3793 3.3760 SSG Sample 2 3.6727 3.7753 3.7735 3.7723 3.7651 3.7619 3.7477 3.7477 3.7474 3.7438 SSG Sample 3 2.9276 3.0600 3.0568 3.0574 3.0490 3.0449 3.0259 3.0256 3.0255 3.0215 SSG Sample 4 3.2265 3.3601 3.3571 3.3548 3.3453 3.3410 3.3224 3.3230 3.3230 3.3200 SSG Sample 5 3.2729 3.4094 3.4000 3.3956 3.3829 3.3796 3.3595 3.3598 3.3601 3.3599 SSG Sample 6 3.3635 3.5084 3.5008 3.4980 3.4815 3.4768 3.4557 3.4500 3.4490 3.4700 SSG Sample 7 3.5379 3.6744 3.6721 3.6699 3.6617 3.6579 3.6396 3.6380 3.6373 3.6340 SSG Sample 8 3.7732 3.8523 3.8514 3.8498 3.8426 3.8399 3.8312 3.8307 3.8307 3.8275 SSG Sample 9 3.0460 3.1585 3.1567 3.1549 3.1472 3.1434 3.1301 3.1292 3.1292 3.1260 SSG Sample 10 2.9573 3.0348 3.0333 3.0318 3.0254 3.0221 3.0151 3.0142 3.0140 3.0100 Note: “T” equals the time interval, in minutes, at which the weights were determined. [0000] TABLE 3 1% Hydrocortisone Acetate Silicone Scar Gel Evaporation Study Results Empty Weigh Weight at Weight at Weight at Weight at Weight at Weight at Weight at Weight at Weight at Boat T = 0 T = 5 T = 10 T = 40 T = 60 T = 180 T = 240 T = 300 T = 1440 (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) HAG Sample 1 3.1592 3.3599 3.3561 3.3524 3.3365 3.3373 3.3089 3.2583 3.2580 3.2582 HAG Sample 2 3.3183 3.4122 3.4094 3.4063 3.3935 3.3874 3.3742 3.3688 3.3642 3.3639 HAG Sample 3 3.4812 3.5898 3.5860 3.5827 3.5672 3.5611 3.5361 3.5380 3.5380 3.5353 HAG Sample 4 3.5457 3.6612 3.6580 3.6559 3.6394 3.6318 3.6052 3.6058 3.6054 3.6032 HAG Sample 5 3.4292 3.5117 3.5086 3.5071 3.4935 3.4881 3.4719 3.4742 3.4742 3.4751 HAG Sample 6 3.6278 3.7158 3.7118 3.7085 3.6952 3.6885 3.6712 3.6716 3.6723 3.6723 HAG Sample 7 3.5343 3.6615 3.6587 3.6554 3.6400 3.6314 3.6007 3.6030 3.6018 3.6002 HAG Sample 8 3.3502 3.4862 3.4820 3.4778 3.4624 3.4536 3.4204 3.4221 3.4204 3.4201 HAG Sample 9 3.5731 3.7100 3.7070 3.7048 3.6927 3.6831 3.6450 3.6450 3.6450 3.6449 HAG Sample 10 3.4784 3.5971 3.5942 3.5890 3.5806 3.5707 3.5412 3.5430 3.5410 3.5392 Note: “T” equals the time interval, in minutes, at which the weights were determined. Calculations [0045] The Percent Weight Loss values were calculated as follows: [0000] %   Weight   Loss = ( Wght .  at   T = 0 - Wght .  of   Empty   Weigh   Boat ) - ( Wght .  at   T = n - Wght .   of   Empty   Weigh   Boat ) ( Wght .  at   T = 0 - Wght .  of   Empty   Weigh   Boat ) × 100 [0046] Where n is the weight recorded at times of 5, 10, 40, 60, 180, 240, 300 and 1440 minutes. [0047] Example: The percent weight loss for “1% Hydrocortisone Acetate Silicone Gel at T=5 minutes would be determined accordingly. [0000] %   Weight   Loss = ( 3.3599   g - 3.1592   g ) - ( 3.3561   g - 3.1592   g ) ( 3.3599   g - 3.1592   g ) × 100 = 1.8934  % [0048] The Percent Weight Loss values were averaged for each of the three products at the appropriate time interval (5, 10, 40, 60, 180, 240, 300 and 1440) and displayed in graphically, see FIG. 1 . Conclusion [0000] 1. The Control Formula Scar Gel, the “30 SPF Sunscreen Silicone Scar Gel” and the “1% Hydrocortisone Acetate Silicone Scar Gel” all reached relatively stable dried weights at the 180 minute mark. EXAMPLE 4 Experimental Details of the SPF Tests [0000] Title: Evaluation of the Static Sun Protection Factor (SPF) of a Sunscreen-Containing Formula Objective: To measure the Static SPF of an over-the-counter (OTC) sunscreen-containing formula and the 8% Homosalate Standard (HMS) in human volunteers according to the FDA Final Monograph Test Product: Test Formulation—Expected SPF 30 Study Design: Non-randomized, with blinded evaluations Results: Five subjects completed the test. The mean SPF of the test product, Test Formulation, was 33.1 (n=5, SD=2.0). The test product would be likely to meet FDA Final Monograph requirements for labeling as Static SPF 30+. 1 Adverse Experiences: No Adverse Experiences were reported Summary: [0056] On the first day of the study each subject received a series of UV doses from a xenon arc solar simulator to an unprotected site on the mid-back. On the second day the minimal erythema dose (MED) was determined as the lowest UV dose which produced mild erythema reaching the borders of the exposure site. Then 100 mg of the test product and 100 mg of the HMS standard were applied to separate, adjacent 50 cm2 areas of the mid-back (8% Homosalate (HMS) Standard provided by Cosmetech Laboratories, Inc., Fairfield, N.J.). [0057] The test product had an expected SPF of 30 and the HMS standard sunscreen had an expected SPF of 4. After a 15-minute drying period UV doses ranging from 0.76 to 1.32 times the product of the MED and 30 were administered to the test sunscreen-protected area. UV doses ranging from 0.64 to 1.56 times the product of the MED and 4 were administered to the HMS standard sunscreen-protected area. A series of UV doses were also administered to a second unprotected site. On the third day the MED was determined for the sunscreen-protected sites and the unprotected site. The SPF of each sunscreen was calculated as the ratio of the MED for each sunscreen-protected site to the final MED. [0058] Detailed procedures for determining the Static Sun Protection Factor according to the FDA Sunscreen Monograph1 are described in the PROTOCOL. [0059] Details of calibrations for Lamps 1, 2, 7, 8, 10, 13 and 14 are shown in the LAMP CALIBRATIONS. [0060] According to the FDA Final Monograph1, the labeled SPF must be calculated as follows: [0000] Labeled SPF=Mean SPF Value− A [0061] Rounded down to the nearest whole number [0062] For SPF values >31, the test product may be labeled as SPF 30+ [0063] Where A=ts/sqrt(n) and represents the 95% confidence interval. [0064] t=upper 5% of student's t distribution [0065] s=Standard Deviation [0066] n=Number of Subjects [0067] For the panel to be valid, the SPF of the HMS standard sunscreen must fall within the standard deviation range of the expected SPF (i.e. 4.47±1.279) and the 95% confidence interval for the mean SPF of the HMS standard sunscreen must contain the value 4. Results: [0068] Five subjects, 2 men and 3 women, who provided written, informed consent, completed the study. Subjects who completed all procedures included 2 with skin type I, 2 with skin type II and 1 with skin type III.1 Ages ranged from 21 to 38 years and the mean age was 30.4 (n=5, SD=7.1). Subject demographic and static SPF results are listed in Table 1. [0069] The mean static SPF of the test product, Test Formulation, was 33.1 (n=5, SD=2.0). The mean SPF of the HMS standard was 4.4 (n=5, SD=0.4). Protocol Deviation: [0070] Protocol Deviations were reported for Subject 04. The Repeat MED and Final SPF evaluations were performed outside of the 22 to 24 hour time frame (21:50 and 21:54 respectively). This Protocol Deviation did not affect study results. Enrollment: [0071] Subject 03 was disqualified during Day 1 procedures for a prohibited medication and Subjects 05 and 06 were disqualified due to procedural error. Data for these subjects were not included in this report. [0000] TABLE 1 Subject Demographic and Static SPF Data for Test Formulation and HMS Standard SRL2008-105: Formulated Solutions, LLC HMS Test HMS Subject SRL Skin Final MED Formulation Standard #* ID# Age Sex Type Lamp (sec) SPF SPF 01 1792 21 F I 8 10 34.50 4.40 02 1702 27 F II 2 10 32.10 4.00 04 373 38 M II 10 10 30.00 4.40 07 1803 29 M III 1 13 34.54 4.38 08 895 37 F I 2 8 34.50 5.00 Mean = 30.4 Mean = 33.1 Mean = 4.4 SD = 7.1 SD = 2.0 SD = 0.4 n = 5 n = 5 n = 5 [0072] Subject 03 disqualified—prohibited med [0073] Subject 05 disqualified—procedural error [0074] Subject 06 disqualified—procedural error Conclusion: [0075] The test product, Reference Test Formulation, would be likely to meet the FDA Final Monograph requirements for labeling as Static SPF 30+. 1 References: [0076] 1. U. S. Food and Drug Administration. Sunscreen Drug Products for Over-the-Counter Human Use; Final Monograph; 21CRF Parts 310, 352, 700 and 740. Federal Register 64 (98) May 21, 1999. pp. 27666-27693 Protocol [0000] Objective: To measure the static sun protection factor (SPF) of an over-the-counter (OTC) sunscreen-containing formula according to the FDA Final Monograph 1 Test Product: Expected SPF 30 Study Design: Non-randomized, with blinded evaluations Subjects: Five qualified male and/or female volunteers with the skin types I, II and/or III1 will be completed for the test product. With permission from the Sponsor, up to 20 additional subjects may be enrolled to complete requirements for FDA Final Monograph testing. 1 Introduction: [0081] The FDA Final Monograph1 describes the procedures for determining the Static sun protection factor. The Static SPF is defined by the ratio of the minimal erythema dose of ultraviolet radiation for sunscreen-protected skin to that for unprotected skin. The minimal erythema dose (MED) is the dose of ultraviolet (UV) radiation that produces mild erythema (sunburn) with clearly defined borders, 22 to 24 hours after administration. Timed UV radiation doses were administered using a xenon arc lamp that simulated solar radiation. The technician monitored the output of the solar simulator using a calibrated radiometer to insure that the erythemally effective irradiance was constant. Readings of erythemally effective irradiance were recorded. Objective: [0082] The objective of this test was to measure the Static SPF of an over-the-counter (OTC) sunscreen-containing formula according to the FDA Final Monograph 1 . Design: [0083] This was a non-randomized study with blinded evaluations. Subjects: [0084] Subjects included up to 25 healthy male and female volunteers completed per product with skin types I, II and/or III 1 (See below). [0000] Erythema and Tanning Reactions to Skin Type First Sun Exposure in Sprinq* I Always burns easily; never tans II Always burns easily; tans minimally III Burns moderately; tans gradually IV Burns minimally; always tans well *Subject-reported responses to 1 hour of summer sun exposure [0085] Subjects reported any OTC or prescription medication used within the week before and during study participation. Subjects also satisfied the following criteria: Inclusion Criteria: [0000] At least 18 years old, providing legally effective, written informed consent Willing and able to keep study appointments and follow instructions Good general health Willing to avoid sun and tanning lamp exposure during the study Exclusion Criteria: [0000] History of abnormal response to UV radiation or sensitivity to any ingredient of the test products Sunburn, suntan, active dermal lesions, uneven skin tones or any condition such as nevi, blemishes or moles that might interfere with study procedures Use of any medication that might affect study results, e.g. photosensitizers, antihistamines, analgesics or anti-inflammatory drugs Pregnancy, nursing or any condition that might increase the risk of study participation Tanning bed or tanning lamp exposure in the last 3 months Study Procedures: [0095] All procedures (product application, UV doses and evaluations) were performed with the subjects in the same position. Day 1: Subject Enrollment [0096] Prospective subjects reported to the testing laboratory and received a complete explanation of study procedures. If they desired to participate and agreed to the conditions of the study, subjects signed a written, witnessed consent form and a permission to release personal health information form, and provided a brief medical history. The back, between the belt-line and shoulder blades, were examined for uneven skin tones and blemishes, using a Woods lamp. The technician completed the Subject History Form and qualified subjects were enrolled in the study. Subject numbers were assigned in the order of study enrollment. MED Dose Administration [0097] A timed series of 5 UV doses, increasing in 25 percent increments, were administered to the mid-back, just below the shoulder blades and above the belt-line. UV doses for the MED, the time doses were completed and lamp readings were recorded on the MED form. [0098] Subjects were instructed to avoid UV exposure, photosensitizers, analgesics, antihistamines and anti-inflammatory medications and to return to the testing laboratory 22 to 24 hours after completion of UV doses. Day 2: MED Determination [0099] Subjects returned to the testing laboratory within 22 to 24 hours after completion of MED doses for evaluation of responses and were questioned non-directively to assess compliance, to identify concomitant medications and to monitor for adverse experiences. A trained evaluator graded responses of the UV exposed sites, under warm fluorescent or tungsten illumination of 450 to 550 lux, using the grading scale shown in Table 1. [0000] TABLE 1 Grading Scale for Erythema Responses to UV Doses Administered to Untreated Sites and Sunscreen Treated Sites 0 No erythemal response 1 Minimally perceptible erythema 2 Mild erythema with clearly defined borders 3 Moderate erythema with sharp borders* 4 Dark red erythema with sharp borders* 5 Dark red erythema with sharp borders and possible edema* 6 Intense erythema with sharp borders and edema* *If moderate, dark red or intense erythema did not reach borders of exposed site, an explanation was to be provided in the comments section of evaluation forms [0100] The MED was determined as the first exposure site in the series that produces an erythema grade of at least 2 (Mild erythema with clearly defined borders). The progression of erythema grades was to be consistent with the UV doses administered. [0101] If there were pronounced tanning responses, the subject was to be considered likely Type IV and not qualified for the study. In this case the subject was to be dropped from the study and replaced. Grades for each UV-exposed site, any comments and the evaluation time were recorded. [0102] If required for practical scheduling, the subject was permitted to leave the testing laboratory at this point and return within one week for completion of Day 2 procedures. Application of Products for SPF Determination [0103] If the study participation of the subject has been interrupted, the subject was to be questioned non-directively to assess compliance, identify concomitant medications and monitor for adverse experiences. [0104] The study technician drew 50 cm 2 rectangles in the designated locations on the subject's back between the belt-line and shoulder blades using a template and an indelible marker. The technician then applied 100 mg of test product in its designated rectangle and 100 mg of the HMS standard in an adjacent rectangle. The sunscreens were applied by “spotting” the material across the area and gently spreading, using a finger cot, until a uniform film is applied to the entire area. [0105] The technician documented product formula designations, test site locations and application time. UV Doses for Static SPF Determinations [0106] After at least 15 minutes, the technician administered a series of 7 progressively increasing, timed UV doses to the sites treated with the test products. The dose series was determined by the product of the expected SPF of each test product, the subject's MED and the following number: [0000] Multiple of Subject's MED and Expected SPF (SPF > 15) 0.76 0.87 0.93 1.00 1.07 1.15 1.32 [0107] The technician documented UV doses, times completed and lamp effective irradiance readings for each test product. UV Doses for the HMS Standard [0108] At least 15 minutes after the application of the HMS standard, the technician administered 7 progressively increasing timed UV doses to the HMS standard site. The dose series was determined by the product of the HMS standard SPF (4), the subject MED and the following numbers: [0000] Multiple of Subject MED and HMS Standard (SPF = 4) 0.64 0.80 0.90 1.00 1.10 1.25 1.56 [0109] The technician documented the UV doses for the HMS standard, time completed and the lamp effective irradiance reading. UV Doses for Repeat MED Determination [0110] The technician administered a timed series of 5 UV doses, increasing by 25 percent increments, to an unprotected area of the mid-back. The series of 5 doses included the original MED in the center as follows: [0000] Multiple of Original MED 0.64 0.80 1.00 1.25 1.56 [0111] UV doses for the repeat MED, time completed and the lamp effective irradiance were recorded. [0112] The technician instructed subjects to return to the testing laboratory for evaluation within 22 to 24 hours after completion of the UV doses for the static SPF, HMS standard SPF and the repeat MED. Day 3: Evaluation of Responses to UV Doses for Static SPF and Repeat MED [0113] Subjects returned to the testing laboratory and were questioned non-directively to assess compliance, to identify concomitant medications and to monitor for adverse experiences. A trained evaluator, who did not participate in product applications or administration of UV doses graded all sites that received UV doses, using the scale shown in Table 1. The technician who applied the test product and administered the UV doses was permitted to assist the evaluator, but the technician not permitted to influence the evaluator in the grading of UV responses. Grades of the responses of all sunscreen-treated sites were recorded. SPF Computation: [0114] The technician determined the repeat MED as above and computed the SPF values for each subject. [0115] The final MED was to be the repeat MED, unless the repeat MED could not be determined. In that case the initial MED would be used as the final MED. [0116] SPF values were calculated as the ratio of the MED for sunscreen-protected sites to the final MED. [0117] The labeled SPF were calculated as follows, based on 20 subjects: [0000] Mean SPF Value−A [0118] (rounded down to nearest whole number) [0119] Where A=ts/sqrt(n) [0120] t=upper 5% of student's t distribution [0121] s=Standard Deviation [0122] n=Number of Subjects [0123] For the panel to be valid the SPF of the HMS standard sunscreen must fall within the standard deviation range of the expected SPF (i.e. 4.47±1.279) and the 95% confidence interval for the mean SPF of the HMS standard sunscreen must contain the value 4. Adverse Experiences: [0124] Any adverse experiences were to be documented in the subject file and immediate medical attention obtained if appropriate. Any serious adverse experience defined as life-threatening or requiring emergency measures was to be reported to the sponsor within 24 hours. All adverse experiences were to be reported to the sponsor. Replacement of Subjects: [0125] Any subject disqualified due to non-compliance or adverse experience was to be replaced. Subjects whose data did not permit successful computation of SPF values were to be replaced. Reference: [0126] 1. U. S. Food and Drug Administration. Sunscreen Drug Products for Over-the-Counter Human Use; Final Monograph; 21CRF Parts 310, 352, 700 and 740. Federal Register 64 (98) May 21, 1999. pp. 27666-27693 [0000] LAMP CALIBRATIONS Apr. 17, 2008 Calibration of Lamps 1, 2, 7, 8, 10 and 14 (Calibration Date) Lamp 1 S/N Lamp 2 S/N Lamp 7 S/N Lamp 8 S/N Lamp 10 S/N Lamp 14 S/N 4533 Filter 4534 Filter 9533 Filter 9560 Filter 9655 Filter 11476 Filter 010806 Bulb 05144 Bulb 080105 Bulb 121805 Bulb 081806C Bulb 07072-2 Bulb Requirements 322470 322474 323771 323769 323774 323006 Colipa 2006 FDA 2007 Range (nm) (Jan. 19, 2008) (Apr. 07, 2008) (Apr, 16, 2008) (Apr. 16, 2008) (Apr. 14, 2008) (Dec. 9, 2007) [1] % [2] % Relative % contribution to erythemal effectiveness <290 0.01 0.00 0.087% 0.012% 0.019% 0.01   <0.1 <0.1 290-300 5.8 4.7 6.7% 6.5% 4.7% 7.1  1.0-8.O 46.0-67.0 290-310 60.6 56.5 61.8% 60.4% 56.7% 62.7 49.0-65.0 29D-320  89.2 86.3 89.3% 87.5% 86.8% 89.0 85.0-90.0 80.0-91.0 290-330 94.3 92.1 94.1% 93.1% 92.5% 93.9 91.5-95.5 86.5-95.5 290-340 96.3 94.5 96.0% 95.6% 94.8% 95.8 94.0-97-0 90.5-97.0 290-350 97.7 96.5 97.4% 97.4% 96.7% 97.4 — 93.5-98.6 290-400 100.0 100.0 99.9% 100.0% 100.0% 100.0 99.9-100   93.5-100.0 Ratios (%) UVAII/UV 26.5 23.3 25.3 30.2% 25.3 24.6 ≧20 — UVAI/UV 62.0 68.0 64.6 60.9% 64.6 65.4 ≧60 — Absolute Values Total Power 98 111 96 128 138 147 <150  <150    (mw/cm 2 )

Disclosed is 1) a method for greatly increasing the solubility of useful actives in siloxane matrix-forming preparations, and 2) the associated preparations, themselves. Volatilizing coagents are utilized to give novel gels containing heretofore siloxane-insoluble additives.

CROSS-REFERENCE TO RELATED APPLICATIONS The present invention is related to those disclosed in: 1) U.S. patent application Ser. No. 10/630,311, filed concurrently herewith, entitled “CIRCUITRY FOR REDUCING LEAKAGE CURRENTS IN A PRE-CHARGE CIRCUIT USING VERY SMALL MOSFET DEVICES;” and 2) U.S. patent application Ser. No. 10/630,504, filed concurrently herewith, entitled “CIRCUITRY FOR REDUCING LEAKAGE CURRENTS IN A TRANSMISSION GATE SWITCH USING VERY SMALL MOSFET DEVICES.” U.S. patent application Ser. Nos. 10/630,311 and 10/630,504 are commonly assigned to the assignee of the present invention. The disclosures of the related patent applications are hereby incorporated by reference for all purposes as if fully set forth herein. TECHNICAL FIELD OF THE INVENTION The present invention is generally directed to analog circuits that are fabricated using small feature-sized MOSFET processes and, in particular, to a circuit that reduces sub-threshold leakage currents in small MOSFET devices connected to sensitive analog circuit nodes. BACKGROUND OF THE INVENTION As the feature size of MOSFET processes shrink, the MOSFET sub-threshold drain-to-source leakage current when the transistor is supposedly turned off becomes increasingly large. In analog circuits where it is critical for a node to stay at high impedance, this increased leakage current may no longer be ignored. When the devices connected to the high impedance node draw large enough leakage currents, the performance of the circuit may suffer significantly. For instance, in a phase-locked loop (PLL), the devices connected to the high-impedance node of the loop filter may draw enough current when the devices are supposedly off to cause jitter in the PLL output. Therefore, there is a need in the art for improved analog circuits that are fabricated using small feature-sized MOSFET processes. In particular, there is a need for circuits that reduce the sub-threshold leakage currents in small MOSFET devices connected to sensitive analog circuit nodes. SUMMARY OF THE INVENTION Low leakage current versions of three commonly used analog switches are shown to demonstrate techniques of reducing MOSFET sub-threshold leakage currents which can be significant in modern small-feature-sized CMOS processes. These circuits may be coupled to the high-impedance node of a phase-locked loop (PLL), for example. The three circuits include 1) pull-up/pull-down devices, 2) a pre-charge circuit, and 3) a transmission switch (T-switch) for analog testing. It should be noted that the low leakage current designs disclosed herein are general purpose and are not necessarily limited to PLL designs. To address the above-discussed deficiencies of the prior art, it is a primary object of the present invention to provide, for use with an operational circuit comprising at least one high-impedance node, a pull-down circuit capable of pulling the high-impedance node down to ground when a pull-down (PD) signal driving the pull-down circuit is Logic 1. According to an advantageous embodiment of the present invention, the pull-down circuit comprises: 1) a first pull-down N-channel transistor having a drain coupled to the high-impedance node, a gate coupled to the PD signal, and a source coupled to a common node; 2) a second pull-down N-channel transistor having a drain coupled to the common node, a gate coupled to the PD signal, and a source coupled to a ground rail;, wherein the first and second pull-down N-channel transistors are off when the PD signal is Logic 0 and are on when the PD signal is Logic 1; and 3) a gate-biasing circuit driven by the PD signal, wherein the gate-biasing circuit is off when the PD signal is Logic 1 and the gate-biasing circuit applies a Logic 1 bias voltage to the common node when the PD signal is Logic 0, the Logic 1 bias voltage creating a negative Vgs bias on the first pull-down N-channel transistor when the PD signal is Logic 0. According to another embodiment of the present invention, the gate-biasing circuit comprises a P-channel transistor having a gate coupled to the PD signal, a drain coupled to the common node, and a source coupled to a VDD power supply rail. According to still another embodiment of the present invention, the gate-biasing circuit comprises: 1) an inverter having an input coupled to the PD signal; and 2) a biasing N-channel transistor having a gate coupled to an output of the inverter, a source coupled to the common node, and a drain coupled to a VDD power supply rail. It is another primary object of the present invention to provide, for use with an operational circuit comprising at least one high-impedance node, a pull-up circuit capable of pulling the high-impedance node up to a high voltage when a pull-up (PU*) signal driving the pull-up circuit is Logic 0. According to an advantageous embodiment of the present invention, the pull-up circuit comprises: 1) a first pull-up P-channel transistor having a drain coupled to the high-impedance node, a gate coupled to the PU* signal, and a source coupled to a common node; a second pull-up P-channel transistor having a drain coupled to the common node, a gate coupled to the PU* signal, and a source coupled to a VDD power supply rail, wherein the first and second pull-up P-channel transistors are off when the PU* signal is Logic 1 and are on when the PU* signal is Logic 0; and a gate-biasing circuit driven by the PU* signal, wherein the gate-biasing circuit is off when the PU* signal is Logic 0 and the gate-biasing circuit applies a Logic 0 bias voltage to the common node when the PU* signal is Logic 1, the Logic 0 bias voltage creating a positive Vgs bias on the first pull-up P-channel transistor when the PU* signal is Logic 1. In another embodiment of the present invention, the gate-biasing circuit comprises a biasing N-channel transistor having a gate coupled to the PU* signal, a drain coupled to the common node, and a source coupled to a ground power rail. In still another embodiment of the present invention, the gate-biasing circuit comprises: 1) an inverter having an input coupled to the PU* signal; and 2) a biasing P-channel transistor having a gate coupled to an output of the inverter, a source coupled to the common node, and a drain coupled to a ground power rail. Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation. A controller may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with a controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts: FIG. 1 illustrates an exemplary phase-locked loop (PLL) that incorporates commonly used analog switches in which MOSFET sub-threshold leakage currents are reduced according to the principles of the present invention; FIG. 2A illustrates a conventional pull-down circuit according to an exemplary embodiment of the prior art; FIG. 2B illustrates a conventional pull-up circuit according to an exemplary embodiment of the prior art; FIG. 3A illustrates a pull-down circuit according to an exemplary embodiment of the present invention; FIG. 3B illustrates a pull-up circuit according to an exemplary embodiment of the present invention FIG. 4 illustrates a conventional pre-charge circuit according to an exemplary embodiment of the prior art; FIG. 5 illustrates a pre-charge circuit according to an exemplary embodiment of the present invention; FIG. 6 illustrates a conventional test circuit according to an exemplary embodiment of the prior art; and FIG. 7 illustrates a test circuit according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION FIGS. 1 through 7 , discussed below, and the various embodiments used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any suitably arranged small feature-sized MOSFET device. FIG. 1 illustrates exemplary phase-locked loop (PLL) 100 , which incorporates commonly used analog switches in which MOSFET sub-threshold leakage currents are reduced according to the principles of the present invention. PLL 100 comprises frequency divider 110 , phase-frequency detector 120 , charge pump and loop filter circuit 130 , voltage controlled oscillator 140 and frequency divider 160 . Frequency divider 110 divides the frequency of the input signal, VIN, by R, where R may be an integer of a fractional value. Frequency divider 150 divides the frequency of the output signal, VOUT, by N, where N may be an integer or a fractional value. PFD 120 receives and compares the frequency-divided reference signal from frequency divider 110 and the frequency-divided feedback signal from frequency divider 150 . Depending on whether the frequency of the feedback signal is greater than or less than the frequency of the reference signal, PFD 130 generates either a Pump Up signal or a Pump Down signal that is applied to charge pump and loop filter 130 . If a Pump Up signal is received, charge pump and loop filter 130 adds charge to the loop filter, which is typically a large storage capacitor. If a Pump Down signal is received, charge pump and loop filter 130 discharges the loop filter. The voltage on the loop filter is the control voltage, VC, at the output of charge pump and loop filter 130 . Voltage-controlled oscillator 140 produces the output signal, VOUT, which has a frequency that is controlled by the control voltage, CV. As the CV voltage increases, the frequency of the VOUT output signal increases. As the CV voltage decreases, the frequency of the VOUT output signal decreases. Thus, through the operation of the negative feedback path in PLL 150 , the frequency of the VOUT output signal is held at some multiple of the frequency of the VIN input signal, where the multiple is determined by the values of R and N of frequency dividers 110 and 150 , respectively. FIG. 2A illustrates conventional pull-down circuit 210 according to an exemplary embodiment of the prior art. Pull-down circuit 210 comprises. N-channel transistor 210 , which has a gate coupled to the pull-down signal, PD, a drain coupled to the VC node at the output of charge pump and loop filter 130 , and a source coupled to the VSS power rail (e.g., ground rail). According to the exemplary embodiment, N-channel transistor 210 is a metal-oxide-silicon field effect transistor (MOSFET). The VC node at the output of charge pump and loop filter 130 is a high impedance node. When the pull-down signal, PD, is at Logic 1, N-channel transistor 210 is turned on, thereby pulling the node VC to ground. This discharges the loop filter capacitor. When PD is Logic 0, N-channel transistor 210 is off and should not have any measurable effect on the PLL operation. If reality, however, if N-channel transistor 210 is made from a small-feature-sized CMOS process, the sub-threshold drain-to-source leakage current (Ids) when N-channel transistor 210 is off is no longer negligible. As a result, even if Vgs of N-channel transistor 210 is zero volts (0 V), Ids of N-channel transistor 210 could be on the order of hundreds of nano-amperes. In the case of PLL 100 , is this non-zero leakage current drains significant charge from the loop filter capacitor even when the PD signal is Logic 0, thereby causing unacceptably large amounts of jitter at the output of PLL 100 . FIG. 2B illustrates conventional pull-up circuit 250 according to an exemplary embodiment of the prior art. Pull-up circuit 250 comprises P-channel transistor 250 , which has a gate coupled to the pull-up signal, PU*, a drain coupled to the VC node at the output of charge pump and loop filter 130 , and a source coupled to the VDD power supply rail. According to the exemplary embodiment, P-channel transistor 250 is a metal-oxide-silicon field effect transistor (MOSFET). The pull-up signal, PU* is an active low signal. The VC node at the output of charge pump and loop filter 130 is a high impedance node. When the pull-up signal, PU*, is at Logic 0, P-channel transistor 250 is turned on, thereby pulling the node VC up to the. VDD rail voltage. This charges the loop filter capacitor. When PU* is Logic 1, P-channel transistor 250 is off and should not have any measurable effect on the PLL operation. If reality, however, if P-channel transistor 250 is made from a small-feature-sized CMOS process, the sub-threshold drain-to-source leakage current (Ids) when P-channel transistor 250 is off is no longer negligible. As a result, even if Vgs of P-channel transistor 250 is zero volts (0 V), Ids of P-channel transistor 250 could be on the order of hundreds of nano-amperes. In the case of PLL 100 , this non-zero leakage current adds significant charge to the loop filter capacitor even when the PU* signal is Logic 1, thereby causing unacceptably large amounts of jitter at the output of PLL 100 . FIG. 3A illustrates pull-down circuit 300 according to an exemplary embodiment of the present invention. Pull-down circuit 300 comprises N-channel transistors 310 , 320 and 330 , and inverter 340 . The gates of N-channel transistors 310 and 320 are coupled to the pull-down signal, PD. The drain of N-channel transistor 310 is coupled to the VC node at the output of charge pump and loop filter 130 . The source of N-channel transistor 310 is coupled to the drain of N-channel transistor 320 . The source of N-channel transistor 320 is coupled to the VSS power rail (e.g., ground rail). The input of inverter 340 is coupled to the pull-down signal, PD. The output of inverter 340 drives the gate of N-channel transistor 330 . The drain of N-channel transistor 330 is coupled to the VDD power supply rail. The source of N-channel transistor 330 is coupled to the drain of N-channel transistor 320 . Pull-down circuit 300 performs the same function as the circuit in FIG. 2A , without the leakage problem. When the pull-down signal, PD, is Logic 1, N-channel transistors 310 and 320 are turned on, thereby pulling the VC node at the output of charge pump and loop filter 130 to ground. Also, when PD is Logic 1, N-channel transistor 330 is turned off and does nothing. It is noted the widths of N-channel transistors 310 and 320 are twice the width of N-channel transistor 210 in order to maintain the same pull-down impedance. When the PD pull-down signal is Logic 0, N-channel transistors 310 and 320 are both off. At the same time, N-channel transistor 330 is turned on, thereby pulling the source of N-channel transistor 310 and the drain of N-channel transistor 320 up to the VDD rail (i.e., Logic 1). As a result, the Vgs voltage of N-channel transistor 310 is negative, rather than merely 0 volts. This is a “hard” shut-off that effectively reduces the sub-threshold leakage current of N-channel transistor 310 to a negligible amount, thereby avoiding leakage problems. Other circuit designs may be used to create a negative Vgs voltage bias on N-channel transistor 310 . For example, in an alternate embodiment of the present invention, N-channel transistor 330 and inverter 340 may be replaced by a single P-channel transistor that has a gate coupled to the PD input signal, a source coupled to the VDD power supply rail, and a drain coupled to the source of N-channel transistor 310 . FIG. 3B illustrates pull-up circuit 350 according to an exemplary embodiment of the present invention. Pull-up circuit 350 comprises P-channel transistors 360 and 370 , and N-channel transistor 380 . The gates of P-channel transistors 360 and 370 are coupled to the pull-up signal, PU*. The drain of P-channel transistor 370 is coupled to the VC node at the output of charge pump and loop filter 130 . The source of P-channel transistor 370 is coupled to the drain of P-channel transistor 360 . The source of P-channel transistor 360 is coupled to the VDD power supply rail. The pull-up signal, PU* also drives the gate of N-channel transistor 380 . The source of N-channel transistor 380 is coupled to the VSS supply rail (i.e., ground). The drain of N-channel transistor 380 is coupled to the common node at the drain of P-channel transistor 360 and the source of P-channel transistor 370 . Pull-up circuit 350 performs the same function as the circuit in FIG. 2B , without the leakage problem. When the pull-up signal, PU*, is Logic 0, P-channel transistors 360 and 370 are turned on, thereby pulling the VC node at the output of charge pump and loop filter 130 up to the VDD supply voltage. Also, when PU* is Logic 0, N-channel transistor 380 is turned off and does nothing. It is noted the widths of P-channel transistors 360 and 370 are twice the width of P-channel transistor 250 in order to maintain the same pull-up impedance. When the pull-up signal, PU*, is Logic 1, P-channel transistors 360 and 370 are both off. At the same time, N-channel transistor 380 is turned on, thereby pulling the source of P-channel transistor 370 and the drain of P-channel transistor 360 down to ground (i.e., Logic 1). As a result, the Vgs voltage of P-channel transistor 370 is positive, rather than merely 0 volts. This is a “hard” shut-off that effectively reduces the sub-threshold leakage current of P-channel transistor 370 to a negligible amount, thereby avoiding leakage problems. Other circuit designs may be used to create a positive Vgs voltage bias on P-channel transistor 310 . For example, in an alternate embodiment of the present invention, N-channel transistor 380 may be replaced by an inverter that is driven by the PU* pull-down signal and a single P-channel transistor that has a gate coupled to the output of the inverter. The P-channel transistor would also have a drain coupled to the VSS power supply rail, and a source coupled to the source of P-channel transistor 370 . FIG. 4 illustrates conventional pre-charge circuit 400 in exemplary charge pump and loop filter 130 according to an exemplary embodiment of the prior art. Pre-charge circuit 400 comprises P-channel transistors 421 - 425 , N-channel transistor 431 , and inverter 410 . P-channel transistor 425 and N-channel transistor 431 form a transmission gate switch. When the Pre-Charge input signal is at Logic 1, pre-charge circuit 400 is enabled and P-channel transistor 425 and N-channel transistor 431 are both on. When the Pre-Charge input signal is at Logic 0, pre-charge circuit 400 is disabled and P-channel transistor 425 and N-channel transistor 431 are both off. When Pre-Charge=1, P-channel transistor 421 is off and P-channel transistor 422 is on. When Pre-Charge=0, P-channel transistor 421 is on and P-channel transistor 422 is off. P-channel transistor 423 and P-channel transistor 424 are connected as diodes (i.e., Vgd=0). It is noted that the gate and drain of P-channel transistor 424 are directly connected together (i.e., Vgd=0 always) and the gate and drain of P-channel transistor 423 are shorted together when P-channel transistor 422 is on (i.e., Vgd=0 when Pre-Charge=1). Because P-channel transistor 423 and P-channel transistor 424 are the same type and size devices and are connected in series between the VDD rail and the VSS rail (i.e., ground), the voltage, VMID, at the drain of P-channel transistor 422 is VDD/2. When Pre-Charge=1, the transmission gate switch formed by P-channel transistor 425 and N-channel transistor 431 is on (i.e., closed), thereby shorting the VMID node to the VC node. This drives the high-impedance VC node to approximately VDD/2. When Pre-Charge=0, the transmission gate switch is off, thereby isolating the VMID node from the VC node. Also, when Pre-Charge=0, P-channel transistor 422 is off and P-channel transistor 421 is on, thereby shorting the gate of P-channel transistor 423 to the VDD rail. Since the source of P-channel transistor 421 also is connected to the VDD rail, the Vgs for P-channel transistor 423 is zero and P-channel transistor 423 is off. This cuts off current flow through P-channel transistor 423 and P-channel transistor 424 . Unfortunately, pre-charge circuit 400 experiences high leakage current when pre-charge circuit 400 is disabled. When Pre-Charge=0, P-channel transistor 423 is off, but P-channel transistor 424 is still on Thus, the VMID node sits at approximately 0 volts. Since Pre-charge=0 is coupled to the gate of N-channel transistor 431 and VMID=0 is coupled to the source of N-channel transistor 431 , the Vgs of N-channel transistor 431 is approximately 0 volts. This permits sub-threshold leakage currents in small-feature-sized processes. Therefore, a leakage current path forms between the high impedance node, VC, and the VSS rail (i.e., ground) through N-channel transistor 431 and P-channel transistor 424 . FIG. 5 illustrates pre-charge circuit 500 in exemplary charge pump and loop filter 130 according to an exemplary embodiment of the present invention. Pre-charge circuit 500 comprises P-channel transistors 521 - 525 , N-channel transistors 531 - 534 , and inverter 510 . P-channel transistor 525 and N-channel transistor 534 form a transmission gate switch. When the Pre-Charge input signal is at Logic 1, pre-charge circuit 500 is enabled and P-channel transistor 525 and N-channel transistor 534 are both on. When the Pre-Charge input signal is at Logic 0, pre-charge circuit 500 is disabled and P-channel transistor 525 and N-channel transistor 534 are both off. When Pre-Charge=1, P-channel transistors 521 and 523 are off and N-channel transistors 531 and 532 are on. When Pre-Charge=0, P-channel transistors 521 and 523 are on and N-channel transistors 531 and 532 are off. When Pre-Charge=1, P-channel transistor 522 and P-channel transistor 524 are connected as diodes (i.e., Vgd=0). The gate and drain of P-channel transistor 522 are shorted together when N-channel transistor 531 is on (i.e., Vgd=0 when Pre-charge=1). Similarly, the gate and drain of P-channel transistor 524 are shorted together when N-channel transistor 532 is on (i.e., Vgd=0 when Pre-Charge=1). Because P-channel transistor 522 and P-channel transistor 524 are the same type and size devices and are connected in series between the VDD rail and the VSS rail (i.e., ground), the voltage, VMID, at the drain of P-channel transistor 522 is VDD/2. The gate and source of N-channel transistor 533 are connected together, so that N-channel transistor 533 is off all the time. N-channel transistor 533 has negligible effect when P-channel transistors 522 and 524 are on. However, when Pre-Charge=0, P-channel transistors 521 and 523 are on and N-channel transistors 531 and 532 are off. Since P-channel transistors 521 and 523 are both on, the gate-to-source voltages (Vgs) of P-channel transistors 522 and 524 are both 0 volts. Therefore, P-channel transistors 522 and 524 are off. Because P-channel transistors 522 and 524 are the same type and size devices, the impedances of P-channel transistors 522 and 524 are approximately the same when P-channel transistors 522 and 524 are off. When pre-charge circuit 500 is in this state, N-channel transistor 533 is off, but has a Vgs of zero volts and therefore has a sub-threshold leakage current. It is noted that when Pre-Charge=0, P-channel transistor 523 is on and shorts the VMID node to the drain of N-channel transistor 532 , which is off. However, N-channel transistor 532 still has a sub-threshold leakage current that can discharge the VMID node through P-channel transistor 523 . Therefore, N-channel transistor 533 is introduced to cancel the leakage current of N-channel transistor 532 . In this way, the VMID node sits at approximately VDD/2. Note the size of N-channel transistor 533 is larger than the size of N-channel transistor 532 in order to compensate for the body effect of N-channel transistor 533 when an n-well process is used. The source of N-channel transistor 534 is coupled to the VMID node and the drain of N-channel transistor 534 is coupled to the VC node. The source of P-channel transistor 525 is coupled to the VMID node and the drain of P-channel transistor 525 is coupled to the VC node. When the VMID node is at VDD/2, the sub-threshold leakage currents of both N-channel transistor 534 and P-channel transistor 525 are negligible because N-channel transistor 534 and P-channel transistor 525 are both “hard” off. That is, the Vgs bias of N-channel transistor 534 is negative (i.e., −VDD/2) and the Vsg bias of P-channel transistor 525 is positive (i.e., +VDD/2). FIG. 6 illustrates conventional test circuit 600 according to an exemplary embodiment of the prior art. For measurement purposes, test circuit 600 transmits the voltage at an internal node (the VC voltage in this case) to an externally accessible test point, namely the input/output (I/O) pad VEXT. Test circuit 600 comprises N-channel transistors 611 - 613 , P-channel transistors 621 and 622 , and inverter 630 . N-channel transistor 611 and P-channel transistor 621 form a first transmission gate switch. N-channel transistor 612 and P-channel transistor 622 form a second transmission gate switch. N-channel transistor 613 operates as a pull-down device. When the ON signal is Logic 1, N-channel transistors 611 and 612 are on, P-channel transistors 621 and 622 are on, and N-channel transistor 613 is off. Since both transmission gates are on, the VC node is shorted to the VEXT node. This allows the user to either monitor or drive the internal analog node, VC. When the ON is Logic 0, both transmission switches are off and N-channel transistor 613 is on and pulls the V 1 node between the transmission switches to ground. This is done to minimize potential interferences from the VEXT external node to internal node VC via capacitive couplings. As in the cases of pull-down circuit 210 and pre-charge circuit 400 , a sub-threshold leakage current path exists from the VC to ground through N-channel transistor 611 and N-channel transistor 613 when test circuit 600 is off. FIG. 7 illustrates test circuit 700 according to an exemplary embodiment of the present invention. For measurement purposes, test circuit 700 transmits the voltage at an internal node (the VC voltage in this case) to an externally accessible test point, namely the input/output (I/O) pad VEXT. Test circuit 700 comprises N-channel transistors 711 - 715 , P-channel transistors 721 - 723 , and inverter 730 . N-channel transistor 711 and P-channel transistor 721 form a first transmission gate switch. N-channel transistor 712 and P-channel transistor 722 form a second transmission gate switch. N-channel transistor 713 and P-channel transistor 723 form a third transmission gate switch. N-channel transistor 715 operates as a pull-down device. The gate and source of N-channel transistor 714 are coupled together (i.e., Vgs=0), so that N-channel transistor 714 is always off. However, N-channel transistor 714 has a sub-threshold leakage current when Vgs=0. When the ON signal is Logic 1, all three transmission gate switches are on, allowing test circuit 700 to function in a manner similar to test circuit 600 . However, the switch sizes in test circuit 700 are 50% larger than those in test circuit 600 to maintain the same on-resistance. When the ON signal is Logic 0, all three transmission gate switches are off. The V 1 node is pulled down to ground by N-channel transistor 715 , keeping interference low. However, the sub-threshold leakage current path is eliminated in test circuit 700 . N-channel transistor 712 is still leaky because its Vgs is 0 volts. However, N-channel transistor 714 is also leaky and has approximately the same impedance as N-channel transistor 712 . So the voltage at the V 2 node is approximately VDD/2 when the V 1 node is pulled down to ground. It is noted that the size of N-channel transistor 714 is bigger than the size of N-channel transistor 712 to compensate for the body effect. Because the V 2 node is at VDD/2 when the V 1 node is at ground and the ON signal is Logic 0, N-channel transistor 711 and P-channel transistor are “hard” off (i.e., Vgs<0 for N-channel transistor 711 and Vgs>0 for P-channel transistor 721 ). Hence, there is a negligible amount of leakage current and no leaky path is connected to the VC node. The above-described circuits can be used to reduce sub-threshold leakage currents in small-feature-sized CMOS processes. All three circuits involve leaky switches when the Vgs values of the MOSFET devices are 0 volts (i.e., when the switches are off). The new circuit designs modify the prior art circuits such that the leakage paths are eliminated by making Vgs<0 for the N-channel devices and Vgs>0 for the P-channel devices. This is accomplished without impacting circuit performances or affecting power consumption. Although the present invention has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims.

A pull-down circuit for pulling a high-impedance node to ground when a pull-down (PD) signal driving the pull-down circuit is Logic 1. The pull-down circuit comprises: 1) a first pull-down N-channel transistor having a drain coupled to the high-impedance node, a gate coupled to the PD signal, and a source coupled to a common node; 2) a second pull-down N-channel transistor having a drain coupled to the common node, a gate coupled to the PD signal, and a source coupled to a ground rail;, wherein the first and second pull-down N-channel transistors are off when the PD signal is Logic 0 and are on when the PD signal is Logic 1; and 3) a gate-biasing circuit driven by the PD signal. The gate-biasing circuit is off when the PD signal is Logic 1 and the gate-biasing circuit applies a Logic 1 bias voltage to the common node when the PD signal is Logic 0. The Logic 1 bias voltage creates a negative Vgs bias on the first pull-down N-channel transistor when the PD signal is Logic 0. An analogous pull-up circuit also is disclosed.

BACKGROUND INFORMATION 1. Field The present disclosure relates generally to aircraft and in particular to a method and apparatus for controlling the flight of an aircraft. Still more particularly, the present disclosure relates to a method, apparatus, and computer program product for controlling thrust generated by the engine of an aircraft. 2. Background Takeoff is a phase of flight when an aircraft transitions from moving along the ground to flying in the air. An aircraft may make this transition when a takeoff speed is reached. The takeoff speed for an aircraft may vary based on a number of factors. These factors include, for example, air density, aircraft gross weight, aircraft configuration, and other suitable factors. The speed needed for a takeoff is relative to the motion of the air. For example, headwind reduces the amount of groundspeed at the point of takeoff. In contrast, a tailwind increases the groundspeed at the point of takeoff. The amount of thrust generated by an engine may affect the maintenance schedule required for an engine. For example, when crosswinds are present, the air into an inlet for an engine may separate. This separation of air may provide poor aerodynamics with respect to fan blades within the engine. If the engine is providing a high-level thrust, poor aerodynamics may cause vibrations on the fan blades. These vibrations may result in requiring more frequent replacement or maintenance of the blades. This type of increased maintenance increases cost and makes the aircraft unavailable more often. One solution is to restrict engine power to a selected level until the forward speed is such that adverse aerodynamics at an inlet of an engine no longer occurs. SUMMARY In one advantageous embodiment, a method is presented for controlling thrust generated by an aircraft. A command is received for a selected level of thrust for the aircraft. A level of thrust provided by an engine for the aircraft is controlled based on a groundspeed and an airspeed of the aircraft in response to receiving the command. In another advantageous embodiment, an apparatus comprises a thrust control process and a processor unit. The thrust control process may be capable of receiving a command for a selected level of thrust generated by an engine. The thrust control process may control a level of thrust provided by the engine based on a groundspeed and an airspeed of an aircraft in response to receiving the command. The thrust control process may execute on the processor unit. In yet another advantageous embodiment, a computer program product for controlling thrust generated by an aircraft comprises a computer recordable storage medium, and program code stored on the computer recordable storage medium. Program code may be present for receiving a command for a selected level of thrust for the aircraft. Program code may also be present for controlling a level of thrust provided by an engine for the aircraft based on a groundspeed and an airspeed of the aircraft in response to receiving the command. The features, functions, and advantages can be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments in which further details can be seen with reference to the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS The novel features believed characteristic of the advantageous embodiments are set forth in the appended claims. The advantageous embodiments, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an advantageous embodiment of the present disclosure when read in conjunction with the accompanying drawings, wherein: FIG. 1 is a diagram of an aircraft in which an advantageous embodiment may be implemented; FIG. 2 is a diagram of a data processing system in accordance with an advantageous embodiment; FIG. 3 is a diagram illustrating a thrust control system in accordance with an advantageous embodiment; FIG. 4 is a diagram illustrating a thrust control unit in accordance with an advantageous embodiment; FIG. 5 is a diagram illustrating limits supplied to engine thrust in accordance with an advantageous embodiment; FIG. 6 is a diagram illustrating limits for thrust in accordance with an advantageous embodiment; FIG. 7 is a diagram illustrating limits for thrust in accordance with an advantageous embodiment; FIG. 8 is a diagram illustrating logic for controlling thrust in accordance with an advantageous embodiment; FIG. 9 is a diagram illustrating logic to generate or enable a groundspeed limit enable signal in accordance with an advantageous embodiment; FIG. 10 is a diagram illustrating logic to generate an airspeed limit enable signal in accordance with an advantageous embodiment; FIG. 11 is a high level flowchart of a process for controlling thrust generated by an aircraft in accordance with an advantageous embodiment; FIG. 12 is a flowchart of a process for controlling thrust generated by an aircraft in accordance with an advantageous embodiment; FIG. 13 is a flowchart of a process for enabling and disabling a groundspeed limit in accordance with an advantageous embodiment; and FIG. 14 is a flowchart of a process for enabling and disabling an airspeed limit in accordance with an advantageous embodiment. DETAILED DESCRIPTION With reference now to the figures, and in particular, with reference to FIG. 1 , a diagram of an aircraft is depicted in which an advantageous embodiment may be implemented. Aircraft 100 is an example of an aircraft in which a method and apparatus for controlling engine power may be implemented. In this illustrative example, aircraft 100 has wings 102 and 104 attached to body 106 . Aircraft 100 includes wing mounted engine 108 , wing mounted engine 110 , and tail 112 . In particular, the different advantageous embodiments may control a level of thrust that may be generated by wing mounted engine 108 and wing mounted engine 110 when aircraft 100 is on the ground. Although a wing mounted twin engine aircraft is illustrated in FIG. 1 , this illustration is provided for purposes of illustrating one type of aircraft in which different advantageous embodiments may be implemented. The different advantageous embodiments may be implemented on other types of aircraft with other numbers of engines and/or configurations of engines. Turning now to FIG. 2 , a diagram of a data processing system is depicted in accordance with an advantageous embodiment. Data processing system 200 is an example of a data processing that may be implemented within aircraft 100 in FIG. 1 . Data processing system 200 may be found in various systems for aircraft 100 . For example, data processing system 200 may be implemented in components used to control the engines. In these different advantageous embodiments, data processing system 200 may be configured to control the thrust generated by these types of engines. In this illustrative example, data processing system 200 includes communications fabric 202 , which provides communications between processor unit 204 , memory 206 , persistent storage 208 , communications unit 210 , input/output (I/O) unit 212 , and display 214 . Processor unit 204 serves to execute instructions for software that may be loaded into memory 206 . Processor unit 204 may be a set of one or more processors or may be a multi-processor core, depending on the particular implementation. Further, processor unit 204 may be implemented using one or more heterogeneous processor systems in which a main processor is present with secondary processors on a single chip. As another illustrative example, processor unit 204 may be a symmetric multi-processor system containing multiple processors of the same type. Memory 206 and persistent storage 208 are examples of storage devices. A storage device is any piece of hardware that is capable of storing information either on a temporary basis and/or a permanent basis. Memory 206 , in these examples, may be, for example, a random access memory or any other suitable volatile or non-volatile storage device. Persistent storage 208 may take various forms depending on the particular implementation. For example, persistent storage 208 may contain one or more components or devices. For example, persistent storage 208 may be a hard drive, a flash memory, or some combination of the above. The media used by persistent storage 208 also may be removable. For example, a removable hard drive may be used for persistent storage 208 . Communications unit 210 , in these examples, provides for communications with other data processing systems or devices. In these examples, communications unit 210 is a network interface card. Communications unit 210 may provide communications through the use of either or both physical and wireless communications links. Input/output unit 212 allows for input and output of data with other devices that may be connected to data processing system 200 . For example, input/output unit 212 may provide a connection for user input through a keyboard and mouse. Display 214 provides a mechanism to display information to a user. Instructions for the operating system and applications or programs are located on persistent storage 208 . These instructions may be loaded into memory 206 for execution by processor unit 204 . The processes of the different embodiments may be performed by processor unit 204 using computer implemented instructions, which may be located in a memory, such as memory 206 . These instructions are referred to as program code, computer usable program code, or computer readable program code that may be read and executed by a processor in processor unit 204 . The program code in the different embodiments may be embodied on different physical or tangible computer readable media, such as memory 206 or persistent storage 208 . Program code 216 is a functional form and located on computer readable media 218 that is selectively removable and may be loaded onto or transferred to data processing system 200 for execution by processor unit 204 . Program code 216 and computer readable media 218 form computer program product 220 in these examples. In one example, computer readable media 218 may be in a tangible form, such as, for example, an optical or magnetic disc that is inserted or placed into a drive or other device that is part of persistent storage 208 for transfer onto a storage device, such as a hard drive that is part of persistent storage 208 . In a tangible form, computer readable media 218 also may take the form of a persistent storage, such as a hard drive, a thumb drive, or a flash memory that is connected to data processing system 200 . The tangible form of computer readable media 218 is also referred to as computer recordable storage media. In some instances, computer readable media 218 may not be removable. Alternatively, program code 216 may be transferred to data processing system 200 from computer readable media 218 through a communications link to communications unit 210 and/or through a connection to input/output unit 212 . The communications link and/or the connection may be physical or wireless in the illustrative examples. The computer readable media also may take the form of non-tangible media, such as communications links or wireless transmissions containing the program code. In some illustrative embodiments, program code 216 may be downloaded over a network to persistent storage 208 from another device or data processing system for use within data processing system 200 . For instance, program code stored in a computer readable storage medium in a server data processing system may be downloaded over a network from the server to data processing system 200 . The data processing system providing program code 216 may be a server computer, a client computer, or some other device capable of storing and transmitting program code 216 . The different components illustrated for data processing system 200 are not meant to provide architectural limitations to the manner in which different embodiments may be implemented. The different illustrative embodiments may be implemented in a data processing system including components in addition to or in place of those illustrated for data processing system 200 . Other components shown in FIG. 2 can be varied from the illustrative examples shown. As one example, a storage device in data processing system 200 is any hardware apparatus that may store data. Memory 206 , persistent storage 208 and computer readable media 218 are examples of storage devices in a tangible form. In another example, a bus system may be used to implement communications fabric 202 and may be comprised of one or more buses, such as a system bus or an input/output bus. Of course, the bus system may be implemented using any suitable type of architecture that provides for a transfer of data between different components or devices attached to the bus system. Additionally, a communications unit may include one or more devices used to transmit and receive data, such as a modem or a network adapter. Further, a memory may be, for example, memory 206 or a cache such as found in an interface and memory controller hub that may be present in communications fabric 202 . The different advantageous embodiments recognize and take into account that currently used systems for limiting engine power may be insufficient. The different advantageous embodiments recognize that currently used systems ramp and/or allow an increase in the maximum engine power based on airspeed. The different advantageous embodiments recognize that using only airspeed may have a susceptibility to the thrust appearing to stop less than the target thrust until sufficient airspeed is attained. Further, the different advantageous embodiments also recognize that the use of airspeed to control the amount of thrust may allow the thrust to be reduced if a gust of wind causes a reduction in airspeed. For example, if a pilot commands or selects full power while applying pressure on the brakes, the engines may increase thrust and hold at around 96 percent power. Once the brakes are released and the aircraft begins to roll forward, the engine power may remain at around 96 percent until the airspeed exceeds a certain threshold. This threshold may be around 30 knots. At this point, the thrust may be ramped or increased to 100 percent power using a linear ramp with increasing airspeed. The different advantageous embodiments, recognize and take into account that situations may exist in which using airspeed to ramp thrust may not result in a linear or smooth increase in power as expected by a pilot. For example, if the aircraft begins rolling forward as the throttles are advanced such that 30 knots of airspeed is achieved before the engines have reached 96 percent power, little, if any, pause in engine power may exist. Further, wind gusts may produce a noticeable rollback or reduction in thrust when these wind gusts reduce the airspeed of the aircraft. The different advantageous embodiments recognize and take into account that a concern may be present in which a pilot may perceive an unusual delay or rollback of the engines as an anomaly and abort a takeoff. Thus, the different advantageous embodiments provide a method and apparatus for limiting thrust in a manner that presents a pilot with a continuously increasing thrust. This limit also ensures that a fan blade threshold is met such that undesirable vibrations that may require more frequent maintenance or sooner maintenance may be avoided. The different advantageous embodiments use a groundspeed limit and an airspeed limit to limit the amount of thrust generated by an engine. This type of system may provide a limit for the amount of thrust, but may allow for continuous thrust increase during a rolling takeoff procedure. When a command is received for a selected level of thrust for an aircraft, the level of thrust provided by the engine may be based both on the groundspeed and the airspeed of the aircraft. A determination may be made as to whether a groundspeed limit for the thrust is to be used based on the groundspeed and the airspeed. In response to the groundspeed limit being present, the level of thrust is provided using the lower value generated between the groundspeed limit and airspeed limit. In response to the groundspeed limit not being used, the level of thrust may be provided using the airspeed limit. At some speed of travel on the ground, the airspeed limit also may no longer be used. Further, one or more of the airspeed limit and the groundspeed limit also may be used again after this use if the requested level of thrust is less than the groundspeed limit and the groundspeed falls below some threshold. In the different advantageous embodiments, the commanded level and the actual level of thrust is displayed to the operator. The operator may observe a lag as the thrust increases, but is less likely to mistakenly identify the lag and/or limits as an anomaly in the engine. Turning now to FIG. 3 , a diagram illustrating a thrust control system is depicted in accordance with an advantageous embodiment. Thrust control system 300 may be implemented using a data processing system such as, for example, data processing system 200 in FIG. 2 . In this example, thrust control system 300 includes throttle controller 302 , thrust control unit 304 , groundspeed sensor 306 , airspeed sensor 308 , and engine 310 . Throttle controller 302 may be a controller located in a cockpit of an aircraft such as, for example, aircraft 100 . Thrust control unit 304 may be a computer physically located at engine 310 . Thrust control unit 304 receives input from groundspeed sensor 306 and airspeed sensor 308 . These various components illustrated for thrust control system 300 may be implemented using currently available components. For example, airspeed sensor 308 may detect airspeed based on impact pressure. For example, airspeed sensor 308 may detect a pressure difference caused by forward motion, which may be total pressure minus static pressure. Groundspeed sensor 306 may be, for example, an inertially based sensor, a global positioning system sensor, or some other suitable type of device. The different advantageous embodiments recognize that an airspeed detected by airspeed sensor 308 may be invalid at speeds less than around 30 knots. With reference now to FIG. 4 , a diagram illustrating a thrust control unit is depicted in accordance with an advantageous embodiment. In this example, thrust control unit 400 is a more detailed example of thrust control unit 304 in FIG. 3 . In this example, thrust control unit 400 includes thrust control process 402 , groundspeed limit unit 404 , airspeed limit unit 406 , and policy 408 . Thrust control process 402 may receive commanded thrust 410 as an input. Commanded thrust 410 may be received from a controller such as, for example, throttle controller 302 in FIG. 3 . Commanded thrust 410 is a command indicating the level of thrust desired by a pilot. Thrust control process 402 also may receive airspeed 412 and groundspeed 414 as inputs when generating engine command 416 . Engine command 416 is the command actually sent to the engine by thrust control unit 400 and may vary from commanded thrust 410 , depending on the application of policy 408 . Policy 408 is a set of rules. A set as used herein refers to one or more items. For example, a set of rules is one or more rules. Policy 408 may be used by thrust control process 402 to determine whether groundspeed limit unit 404 and/or airspeed limit unit 406 should be used to provide limits when generating engine command 416 . If neither groundspeed limit 404 nor airspeed limit 406 limit is applied, engine command 416 may be the same as commanded thrust 410 . Groundspeed limit unit 404 and airspeed limit unit 406 are functions that may be used to limit the amount of thrust in engine command 416 . The limits generated by these units may be used to limit the amount of thrust requested in commanded thrust 410 . In other words, groundspeed limit unit 404 and/or airspeed limit unit 406 may generate limits for the level of thrust for engine command 416 . With the limits that may be generated by groundspeed limit unit 404 and/or airspeed limit unit 406 , engine command 416 may provide a level of thrust that is less than commanded thrust 410 depending on the speed of aircraft. In these examples, groundspeed limit unit 404 applies when the groundspeed of the aircraft is less than some limit. Groundspeed limit unit 404 may be disabled when the groundspeed or the airspeed exceeds some threshold. The threshold for the groundspeed and airspeed are different in these examples. The groundspeed threshold for disabling groundspeed limit unit 404 may be higher than the airspeed threshold in these examples. Groundspeed limit unit 404 is implemented as a ramp function using groundspeed 414 . In this manner, the thrust may increase continuously from a lower limit up to an upper limit. This upper limit in these examples is an airspeed thrust limit. This airspeed thrust limit may be set at a level to prevent undesirable vibrations in the fan blades that may occur due to changes in aerodynamics caused by crosswinds. In these illustrative examples, groundspeed limit unit 404 may be implemented in a number of different ways. For example, groundspeed limit unit 404 may be implemented as a table, a series of equations, or some other suitable function. For example, groundspeed limit unit 404 may provide for a groundspeed using the following equation: maximum thrust=((6/55)*groundspeed)+90. Alternatively, a table may set the limit for the thrust based on the groundspeed. Airspeed limit unit 406 is an upper limit to the thrust that may be commanded. This limit also may be disabled when the airspeed is above a selected level. In these examples, airspeed limit unit 406 may be implemented using logical hysteresis or any other suitable function or process. For example, the limit may switch off when airspeed increases from some airspeed to another airspeed. Further, the limit may be switched on or used when the airspeed decreases from a higher airspeed to a lesser airspeed. For example, the limit may be 96 percent of the maximum thrust when the airspeed is less than 50 knots. When the airspeed becomes greater than 50 knots, the limit is then the maximum thrust. The limit may be turned back on if the airspeed decreases from a level that is greater than 35 knots to less than 35 knots. When that occurs, the limit may be set to 96 percent of the maximum thrust rather than providing maximum thrust. With reference now to FIG. 5 , a diagram illustrating limits supplied to engine thrust is depicted in accordance with an advantageous embodiment. In this example, graph 500 illustrates groundspeed on horizontal axis 502 and airspeed on horizontal axis 504 . The thrust is a percentage of maximum thrust. Thrust in percent is represented by vertical axis 505 . Line 506 illustrates a groundspeed limit, while line 508 illustrates an airspeed limit. Line 510 illustrates a resulting limit from these two limits. The resulting limit in line 510 may change depending on whether wind is present. In this example, no wind is present. The groundspeed limit represented by line 506 is level until 10 knots groundspeed is reached. The amount of thrust that may be generated increases as a ramp until 65 knots is reached. At 65 knots, the thrust limit is level. The airspeed limit represented by line 508 is level until an airspeed of 50 knots is reached. At that point, the airspeed limit is removed and the maximum thrust may be generated. As can be seen by this example, the groundspeed limit is removed when the airspeed reaches 50 knots. With reference now to FIG. 6 , a diagram illustrating limits for thrust is depicted in accordance with an advantageous embodiment. In this example, graph 600 , horizontal axis 602 represents groundspeed, while horizontal axis 604 represents airspeed. Vertical axis 606 represents thrust. Line 608 represents a groundspeed limit, while line 610 represents an airspeed limit. Line 612 represents a resulting limit from these two limits. In this example, a 15 knot headwind is encountered by the aircraft. As can be seen, an airspeed of 50 knots is reached more quickly as compared to graph 500 with the presence of a headwind. When 50 knots is reached, the groundspeed limit is no longer effective. Further, the airspeed limit is also removed resulting in power being increased to a maximum thrust for the engine. With reference now to FIG. 7 , a diagram illustrating limits for thrust is depicted in accordance with an advantageous embodiment. In graph 700 , horizontal axis 702 represents groundspeed, while horizontal axis 704 represents airspeed. Vertical axis 706 represents thrust. Line 708 represents a groundspeed limit, while line 710 represents an airspeed limit. Line 712 illustrates the resulting limit between the airspeed limit and the groundspeed limit. In this example, a 15 knot tailwind is present. As a result, an airspeed of 50 knots is not reached until the groundspeed of 65 knots also is reached. As a result, the limit is not removed until the groundspeed has reached 65 knots in this example. With reference to FIGS. 8-10 , an example of logic for a thrust control process is depicted in accordance with an advantageous embodiment. The logic illustrated in FIGS. 8-10 are simplified diagrams of logic that may be used. These simplified diagrams are presented for purposes of illustrating logic on a high level for use in a thrust control process, such as thrust control process 402 . The actual logic used to implement these processes may include other logic components in addition to or in place of the ones depicted in these figures. With reference now to FIG. 8 , a diagram illustrating logic for controlling thrust is depicted in accordance with an advantageous embodiment. Logic 800 in FIG. 8 is an example of logic that may be implemented in thrust control process 402 in FIG. 4 . In this example, logic 800 receives command 802 as an input. Logic 800 also receives groundspeed 804 , groundspeed limit enable 806 , airspeed 808 , and airspeed limit enable 810 as inputs. Groundspeed 804 is sent to groundspeed limit unit 812 . The output of groundspeed limit unit 812 is a groundspeed limit for a thrust level that is based on groundspeed 804 . The output of groundspeed limit unit 812 may be a thrust level that is less than that in command 802 . When groundspeed limit enable is a logic “1”, groundspeed limit unit 812 is used to control thrust. This thrust level is input into switch 814 . Switch 814 may be enabled by groundspeed limit enable 806 . Additionally, command 802 also is input into switch 814 . The output of switch 814 is sent into minimum unit 816 . Airspeed 808 is entered as an input into airspeed limit unit 818 . Airspeed limit unit 818 generates an airspeed limit for a thrust level based on airspeed 808 . The output of airspeed limit unit 818 may be a thrust level that is less than the amount of thrust requested by command 802 . This thrust level is sent to switch 820 . Switch 820 also receives command 802 as an input. Switch 820 may be enabled by airspeed limit enable 810 . When airspeed limit enable is a logic “1”, airspeed limit unit 818 is used to control thrust. The output of switch 820 is sent to minimum unit 816 . Minimum unit 816 selects the lower value of the outputs of switch 814 and switch 820 . In these examples, groundspeed limit unit 812 is typically a lower limit than airspeed limit unit 818 . Then this output forms command 822 which is used to control the engine. In these examples, command 802 also forms thrust display 824 which is an output for the display that is seen by the pilot. In the different advantageous embodiments, although command 822 may be lower than command 802 , the pilot sees the same level of commanded thrust in command display 824 as command 802 . The pilot may perceive a lag in the thrust increasing as the airspeed increases. This increase in thrust, however, may be maintained as a constant increase to avoid aborting a takeoff when an engine anomaly is not actually present. With reference now to FIG. 9 , a diagram illustrating logic to enable a groundspeed limit is depicted in accordance with an advantageous embodiment. In this example, logic 900 receives a number of different inputs. These inputs include aircraft on ground 902 , groundspeed valid 904 , groundspeed 906 , constant 908 , airspeed valid 910 , airspeed 912 , and constant 914 . In this example, aircraft on ground 902 indicates whether the aircraft is on the ground. A logic “1” indicates that the aircraft is on the ground in these examples. Groundspeed valid 904 is a logic “1” if the groundspeed is valid. Groundspeed 906 is the groundspeed detected by a groundspeed sensor. A groundspeed may not be valid if, for example, a groundspeed sensor is disabled or faulty. Constant 908 in this example is a speed limit at which the groundspeed limit should be enabled. In this example, constant 908 is 70 knots. Groundspeed 906 and constant 908 are compared by comparator 911 . Comparator 911 determines whether groundspeed 906 is less than constant 908 . If groundspeed 906 is less than constant 908 , a true value is generated by comparator 911 and sent into AND gate 915 . If groundspeed 906 is not less than constant 908 , a false value is generated by comparator 911 and sent into AND gate 915 . AND gate 915 also receives groundspeed valid 904 and aircraft on ground 902 as inputs. The output of AND gate 915 is true if all of the inputs are true. Airspeed 912 and constant 914 are sent into comparator 916 . In these examples, if airspeed 912 is greater than constant 914 , the output of comparator 916 is the logic “1.” This output is sent into AND gate 918 . AND gate 918 also receives airspeed valid 910 as an input. If the airspeed is valid and airspeed 912 is greater than constant 914 , a logic “1” is output by AND gate 918 . This output is sent into OR gate 920 . Additionally, the output of AND gate 915 is sent through inverter 922 into OR gate 920 . The output of OR gate 920 is sent into latch 922 . Latch 922 also receives the output of AND gate 915 as an input. When the output of AND gate 915 is true, the output of latch 922 is set true, and remains true until the output of OR gate 920 is true. As long as the output of OR gate 920 is true, the output of latch 922 is false. The output of latch 922 forms groundspeed limit enable 924 , which is used in logic 800 . More specifically, groundspeed limit enable 924 is an example of groundspeed limit enable 806 in FIG. 8 . In essence, groundspeed logic 900 determines whether the groundspeed limit is to be used. In these examples, logic 900 enables the groundspeed limit when the groundspeed is valid, the groundspeed is less than 70 knots, and the aircraft is on the ground. Once logic 900 enables the groundspeed limit, this limit may be disabled if the groundspeed becomes invalid, the groundspeed exceeds 70 knots, the aircraft is in the air, or the airspeed is valid and the airspeed is greater than 50 knots. If the groundspeed limit has been disabled with speed that is above a selected level, or if the groundspeed is invalid, the groundspeed limit may be re-enabled. In this example, the disabling speed may be an airspeed of 50 knots and/or a groundspeed of 70 knots. The groundspeed may be re-enabled if the commanded or requested thrust is less than the groundspeed limit for the current groundspeed, the groundspeed is valid, and the groundspeed falls below 20 knots. With reference now to FIG. 10 , a diagram illustrating logic to generate an airspeed limit enable signal is depicted in accordance with an advantageous embodiment. In this example, logic 1001 receives a number of different inputs. These inputs include, for example, aircraft on ground 1000 , airspeed 1002 , constant 1004 , airspeed valid 1006 , groundspeed valid 1008 , groundspeed 1010 , and constant 1012 . In this example, aircraft on ground 1000 is sent into latch 1014 . Airspeed 1002 and constant 1004 are sent to comparator 1016 . In this example, constant 1004 is 50 knots. If airspeed 1002 is greater than constant 1004 , a logic “1” is sent into AND gate 1018 . AND gate 1018 also receives airspeed valid 1006 as an input. The output of AND gate 1018 is sent into OR gate 1020 . Airspeed valid 1006 is sent through inverter 1022 to the input of AND gate 1024 . Groundspeed valid 1008 also forms an input into AND gate 1024 . Groundspeed 1010 and constant 1012 are sent to comparator 1026 . In these examples, comparator 1026 determines whether groundspeed 1010 is less than constant 1012 . The output of comparator 1026 is sent through inverter 1027 to AND gate 1024 . The output of AND gate 1024 is sent to OR gate 1020 . Aircraft on ground 1000 is also an input into OR gate 1020 . Aircraft on ground 1000 is sent through inverter 1026 into OR gate 1020 . If groundspeed 1010 is less than constant 1012 , the output of comparator 1026 is a logic “1” in these examples. Constant 1012 has a value of 70 knots in this example. The output of OR gate 1020 is sent as an input into latch 1014 . The output of latch 1014 is set true when the aircraft is on the ground. When any of the input conditions cause the output of OR gate 1020 to be true, the output of latch 1014 is held false. The output of latch 1014 forms airspeed limit enable 1028 . This value is an input into logic 800 in FIG. 8 . Airspeed limit enable 1028 is an example of groundspeed limit enable 806 in FIG. 8 . In this example, logic 1001 disables the airspeed limit when the airspeed is greater than 50 knots. The airspeed limit may be re-enabled in these examples, if the airspeed is less than 35 knots or if the airspeed is invalid and the groundspeed is valid and less than 20 knots, and if the commanded level thrust is less than the airspeed limit. The logic illustrated in FIGS. 8-10 are provided as an example of one manner in which groundspeed and airspeed may be used to control thrust during takeoff. This example is not meant to imply physical or architectural limitations to the manner in which other advantageous embodiments may be implemented. With reference now to FIG. 11 , a high level flowchart of a process for controlling thrust generated by an aircraft is depicted in accordance with an advantageous embodiment. The process illustrated in FIG. 11 may be implemented in thrust control process 402 in FIG. 4 . The process begins by receiving a command for a desired level of thrust for an aircraft on the ground (operation 1100 ). The process sends the command to a thrust display (operation 1102 ). The thrust display in operation 1102 may be, for example, thrust display 312 in FIG. 3 . The process controls a level of thrust actually provided by an engine in the aircraft based on a groundspeed and an airspeed (operation 1104 ), with the process terminating thereafter. Operation 1104 uses a lower limit of thrust set by a ground speed limit and an airspeed limit to control the level of thrust of the engine for the aircraft. The level of thrust provided is based on the desired level of thrust and the lower limit, wherein the level of thrust is a continuous linear increase in thrust limited by the groundspeed limit and the airspeed limit. In other words, the level of thrust does not exceed the lower of the two limits as long as the limits are enabled or being used in the manner described in these examples. With reference now to FIG. 12 , a flowchart of a process for controlling thrust generated by an aircraft is depicted in accordance with an advantageous embodiment. The process illustrated in FIG. 12 may be implemented in a software component such as, for example, thrust control process 402 in FIG. 4 . More specifically, FIG. 12 is a more detailed illustration of the process in FIG. 11 . The process begins by receiving a command for a selected level of thrust for the aircraft (operation 1200 ). A determination is made as to whether a groundspeed limit has been enabled (operation 1202 ). If the groundspeed limit has been enabled, the thrust command is set using the groundspeed limit based on the current groundspeed (operation 1204 ), with the process terminating thereafter. With reference again to step 1202 , if the groundspeed limit is not enabled, a determination is made as to whether an airspeed limit has been enabled (operation 1206 ). If the airspeed limit has been enabled, the thrust command is set using the airspeed limit based on the current airspeed (operation 1208 ), with the process terminating thereafter. With reference again to operation 1206 , if the airspeed limit is not enabled, the process sets the thrust command as the received command (operation 1210 ), with the process terminating thereafter. In this case, the commanded thrust is the actual level of thrust that is sent as a thrust command to the engine. In operation 1210 , no limits are applied to the actual thrust since the groundspeed limit and the airspeed limit are not enabled. With reference now to FIG. 13 , a flowchart of a process for enabling and disabling a groundspeed limit is depicted in accordance with an advantageous embodiment. The process illustrated in FIG. 13 may be implemented in a software component such as, for example, thrust control process 402 in FIG. 4 . The process begins by determining whether the aircraft is on the ground (operation 1300 ). If the aircraft is not on the ground, the process disables the groundspeed limit (operation 1302 ). Next, the disable flag is set as true (operation 1304 ), with the process terminating thereafter. With reference again to operation 1300 , if the aircraft is on the ground, a determination is made as to whether the disable flag is set equal to true (operation 1306 ). This determination is made to identify whether the groundspeed limit has been previously disabled, but may need to be re-enabled, for example if the aircraft has left the ground but returned to the ground. If the disable flag is set equal to true, a determination is made as to whether the groundspeed is valid (operation 1308 ). If the groundspeed is not valid, the groundspeed limit is disabled (operation 1310 ) and the process sets the disable flag equal to true (operation 1312 ), with the process terminating thereafter. With reference again to operation 1308 , if the groundspeed is valid, a determination is made as to whether the groundspeed is less than 20 knots (operation 1314 ). The threshold value of 20 knots is set at a speed that indicates that the aircraft is no longer taking off. In this case, the aircraft either was taking off and aborted the take off or took off and subsequently landed. If the groundspeed is not less than 20 knots, the process proceeds to operation 1310 as described above. Otherwise, a determination is made as to whether the thrust is less than the thrust command (operation 1316 ). In this example, the thrust command is the command or desired thrust requested by pilot. If the thrust is not less than the thrust command, the process proceeds to operation 1310 as previously described. Otherwise, the process re-enables the groundspeed limit (operation 1318 ). The process then sets the disable flag to false (operation 1320 ), with the process terminating thereafter. With reference again to operation 1306 , if the disable flag is not true, a determination is made as to whether the airspeed is valid (operation 1322 ). If the airspeed is valid, a determination is made as to whether the airspeed is greater than 50 knots (operation 1324 ). If the airspeed is greater than 50 knots, the groundspeed limit is disabled (operation 1326 ). The process then sets the disable flag equal to true (operation 1328 ), with the process terminating thereafter. With reference again to operation 1324 , if the airspeed is not greater than 50 knots, the groundspeed limit is enabled (operation 1330 ). The process then sets the disable flag equal to false (operation 1332 ), with the process terminating thereafter. With reference again to operation 1322 , if the airspeed is not valid, a determination is made as to whether the groundspeed is valid (operation 1334 ). If the groundspeed is not valid, the process proceeds to operation 1326 as described above. If the groundspeed is valid, a determination is made as to whether the groundspeed is less than 70 knots (operation 1336 ). In this example, the 70 knot groundspeed level provides a 20 knot margin above the airspeed limit of 50 knots. This margin allows for continuous engine acceleration for a takeoff in a 15-knot tailwind, as illustrated in FIG. 7 , and provides an additional 5 knot margin to account for uncertainty in the groundspeed sensing system. Of course, other thresholds may be selected depending on the implementation. If the groundspeed is not less than 70 knots, the process proceeds to operation 1326 . Otherwise, the process proceeds to operation 1330 as described above. With reference now to FIG. 14 , a flowchart of a process for enabling and disabling an airspeed limit is depicted in accordance with an advantageous embodiment. The process illustrated in FIG. 14 may be implemented in a software component such as, for example, thrust control process 402 in FIG. 4 . The process begins by determining whether the aircraft is on the ground (operation 1400 ). If the aircraft is not on the ground, the process disables the airspeed limit (operation 1402 ). The process then sets the disable flag equal to true (operation 1404 ), with the process terminating thereafter. With reference again to operation 1400 , if the aircraft is on the ground, a determination is made as to whether the disable flag is set equal to true (operation 1406 ). If the disable flag is true, a determination is made as to whether the airspeed is valid (operation 1408 ). If the airspeed is valid, a determination is made as to whether the airspeed is less than 35 knots (operation 1410 ). If the airspeed is less than 35 knots, a determination is made as to whether the thrust is less than the thrust command (operation 1412 ). If the thrust is less than the thrust command, the process re-enables the airspeed limit (operation 1414 ) and sets the disable flag to false (operation 1416 ), with the process terminating thereafter. In operation 1412 , if the thrust is not less than the thrust command, the process disables the airspeed limit (operation 1418 ) and sets the disable flag equal to true (operation 1420 ). With reference again to operation 1410 , if the airspeed is not less than 35 knots, the process also proceeds to operation 1418 . In operation 1408 , if the airspeed is not valid, a determination is made as to whether the groundspeed is valid (operation 1422 ). If the groundspeed is valid, a determination is made as to whether the groundspeed is less than 20 knots. If the groundspeed is less than 20 knots, the process proceeds to operation 1412 as described above. Otherwise, the process proceeds to operation 1418 as previously described. In operation 1422 , the process proceeds to operation 1418 if the groundspeed is not valid. With reference again to operation 1406 , if the disable flag is not true, a determination is made as to whether the airspeed is valid (operation 1426 ). If the airspeed is valid, a determination is made as to whether the airspeed is greater than 50 knots (operation 1428 ). If the airspeed is greater than 50 knots, the process disables the airspeed limit (operation 1430 ). The process then sets the disable flag equal to true (operation 1432 ), with the process terminating thereafter. As an example, the threshold of 50 knots may be the airspeed at which inlet separation due to crosswinds has been eliminated, and full thrust is allowed. If the airspeed is not greater than 50, the process enables the airspeed limit (operation 1434 ). The process then sets the disable flag to false (operation 1436 ), with the process terminating thereafter. With reference again to operation 1426 , if the airspeed is not valid, a determination is made as to whether the groundspeed is valid (operation 1438 ). If the groundspeed is valid, a determination is made as to whether the groundspeed is less than 70 knots (operation 1440 ). If the groundspeed is less than 70 knots, the process proceeds to operation 1434 as described above. The 70 knot groundspeed limit is selected to provide a margin above the 50 knot airspeed limit. Otherwise, the process proceeds to operation 1430 as previously described. The process also proceeds to operation 1430 in operation 1438 if the groundspeed is not valid. The different thresholds illustrated in FIGS. 13 and 14 have been selected for purposes of depicting one implementation and are not meant to limit the manner in which other advantageous embodiments may be implemented. For example, in other advantageous embodiments, other groundspeed thresholds may be used other than those illustrated. The flowcharts and block diagrams in the different depicted embodiments illustrate the architecture, functionality, and operation of some possible implementations of apparatus, methods and computer program products. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of computer usable or readable program code, which comprises one or more executable instructions for implementing the specified function or functions. In some alternative implementations, the function or functions noted in the block may occur out of the order noted in the figures. For example, in some cases, two blocks shown in succession may be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Thus, the different advantageous embodiments provide a method, apparatus, and program code for managing thrust levels in an aircraft. The different advantageous embodiments receive a command for a selected amount of thrust. The actual amount of thrust generated by the engine may be controlled based on the groundspeed and airspeed of the aircraft. In these different advantageous embodiments, an airspeed limit and a groundspeed limit may be applied to the received command to identify the actual command to be sent to the engine to generate thrust. Using the different advantageous embodiments, an operator of the aircraft perceives a constant increase in thrust without reaching speed limits that may produce additional wear and tear on the engine. In particular, undesired vibrations on fan blades in the engine may be avoided to reduce the frequency of maintenance for these and other components. The operator may only perceive a lag in engine thrust. As a result, the operator may not mistakenly perceive an anomaly in the engine requiring aborting the takeoff. The different advantageous embodiments can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment containing both hardware and software elements. Some embodiments are implemented in software, which includes but is not limited to forms, such as, for example, firmware, resident software, and microcode. Furthermore, the different embodiments can take the form of a computer program product accessible from a computer usable or computer readable medium providing program code for use by or in connection with a computer or any device or system that executes instructions. For the purposes of this disclosure, a computer usable or computer readable medium can generally be any tangible apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer usable or computer readable medium can be, for example, without limitation an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, or a propagation medium. Non-limiting examples of a computer readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk, and an optical disk. Optical disks may include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) and DVD. Further, a computer usable or computer readable medium may contain or store a computer readable or usable program code such that when the computer readable or usable program code is executed on a computer, the execution of this computer readable or usable program code causes the computer to transmit another computer readable or usable program code over a communications link. This communications link may use a medium that is, for example without limitation, physical or wireless. A data processing system suitable for storing and/or executing computer readable or computer usable program code will include one or more processors coupled directly or indirectly to memory elements through a communications fabric, such as a system bus. The memory elements may include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some computer readable or computer usable program code to reduce the number of times code may be retrieved from bulk storage during execution of the code. Input/output or I/O devices can be coupled to the system either directly or through intervening I/O controllers. These devices may include, for example, without limitation, keyboards, touch screen displays, and pointing devices. Different communications adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Non-limiting examples are modems and network adapters are just a few of the currently available types of communications adapters. The description of the different advantageous embodiments has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Further, different advantageous embodiments may provide different advantages as compared to other advantageous embodiments. The embodiment or embodiments selected are chosen and described in order to best explain the principles of the embodiments, the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.

A method is presented for controlling thrust generated by aircraft engines. Engine thrust is controlled based on aircraft groundspeed and airspeed during the initial part of takeoff. Limiting thrust at low groundspeed during the initial phase of takeoff has significant benefits that reduce engine stress during this brief but critical phase leading to flight. Logical elements combine both groundspeed and airspeed in such a way that the operator perceives a smooth progressive thrust increase consistent with normal engine operation.

FIELD OF THE INVENTION [0001] This invention relates generally to animal controllers. More specifically, this invention pertains to a prod that controls animals with discharges of electrical energy. BACKGROUND OF THE INVENTION [0002] Devices that provide an electric shock to control behavior or movement of animals are well known. These devices, known as stock or cattle prods, are available in a variety of shapes and sizes and can be characterized in that they are able to control animals using high voltage electrical discharges. Generally, stock prods are hand held devices that comprise a housing that contains a power source, circuitry used to generate high voltage, and a pair of high voltage electrodes. The stock prod's power source is typically a dry-cell battery that is connected to an input of the circuitry used to generate the high voltage, with the high voltage generated by a step up transformer and/or a capacitor multiplier circuit. The high voltage output generated by the circuitry is typically connected to a pair of electrodes, which extend away from the exterior of the housing. Preferably, the electrodes are spaced apart from each other by a distance that is sufficient to prevent discharge therebetween. In use, the prod is activated to generate high voltage at the electrodes and the tips of the electrodes are brought into contact with, or in close proximity to, the skin of an animal. As the tips of the electrodes near or touch the animal's skin, the prod discharges leaving the animal with a gentle reminder that it should move or otherwise modify its behavior. [0003] Present stock prods are designed to deliver each discharge as a steady or constant stream of high voltage oscillations or pulses having a predetermined intensity and duration. For example, a discharge may have an intensity of 10,000 volts at a frequency of 2,000 oscillations or pulses per second. It is important to note that the amount of energy expended with each discharge is directly related to battery life. For example, a prod having four C-cell batteries might be able to produce two hours of discharges before the prod loses its effectiveness, whereas a prod having six D-cell batteries might be able to produce three or more hours of discharges before the prod loses its effectiveness. It should be apparent, then, that with provision of additional and/or larger batteries the number of discharges that a prod is able to produce will increase accordingly and the life of the prod will be extended. The drawback with this approach, however, is that extra and/or larger batteries add weight and size to the prod and it eventually becomes too heavy and bulky to operate comfortably for extended periods of time. Alternatively, modifying the output of the prod's discharge can extend the battery life of a prod. There are several ways to do this. [0004] One way is by reducing the duration of each oscillation or pulse. Another way is by lowering the voltage potential that is generated between the tips of the electrodes. In either case, the shock intensity felt by the animal is also reduced. As one may expect, the major drawback to employing such methods is that the increased battery life comes at the expense of operational effectiveness. This could be potentially life threatening, particularly when the operator is unable to administer an effective shock to a particularly large and/or agitated animal, or when an animal's skin is covered with a thick coat of hair. [0005] Regardless of the particular way in which the battery life of a prod is extended, each time the prod is used, the batteries become weaker and the shock intensity diminishes. Eventually, there will be a point where the prod will no longer operate as intended. This is to be expected. The problem is that the battery life of the prod cannot be accurately predicted by merely observing the prod, and an operator has no way of knowing if the battery is capable of generating an hour's worth of discharges or is on the verge of failure. More often than not, the prod will suddenly go dead without any warning. This can be particularly dangerous, especially if the operator is in the midst of a herding operation involving scores of animals. There are several ways in which to prevent the occurrence of such a sudden and potentially catastrophic event. [0006] One way is to periodically replace the batteries of the power source. This is very effective, but it can become quite costly if the batteries are frequently replaced, and it can be wasteful because perfectly good batteries may be thrown away and end up in a landfill. Moreover, it is not always possible to determine if the new batteries are themselves defective or substandard. That is, the batteries could be defective and fail prematurely. Another way to lessen the chance of having a sudden prod failure is to informally test the prod by creating a spark gap between the tips of the electrodes and observing the size of the high voltage arc and accompanying noise that is generated. The problem with this approach is that the inferences drawn from observing the spark are subjective. Moreover, the spark may be masked by bright daylight, accentuated by shadows, or skewed by variable atmospheric conditions such as high humidity, and the observer may overestimate or underestimate the operational capability and condition of the prod and it's battery life. [0007] In a related matter, the above-mentioned stock prods are designed to operate at a given supply voltage, which may be based on the number of batteries used or based on a pre-engineered battery pack. So, for example, a prod may be designed to operate at six volts, nine volts, or in the case of a battery pack, fractional voltages such as seven and one-half volts. In either case, the stock prod's circuit is designed to draw a given amount of current for one particular supply voltage, resulting in a given battery life and given shock intensity. It is important to note that variations in the supply voltage and/or supply impedance can lead to variations in the supply current and variations in the discharge produced at the output end of the prod, which can affect the shock intensity and/or battery life of the prod. Such variations can be caused by changes in battery temperature, the configuration or size designation of the battery, and battery construction. Variability also exists between similarly sized batteries having different manufacturers. [0008] The high voltage potential in present stock prods can be generated by several methods. One method is by using a step-up transformer, which typically comprises a primary (input) winding and a single secondary (output) winding, and has a core that is allowed to float (i.e., not connected to anything in an electrical sense). A drawback to such an arrangement is that electric fields and small amounts of leakage current can cause the core to be charged to an undesirable voltage potential that can lead to transformer failure. In an alternative configuration, the core may be connected to ground in the circuit, typically one of the secondary winding connections. A drawback with this arrangement is, relative to the grounded core, the non-grounded end of the secondary winding becomes charged to a voltage that is equivalent to the output of the prod, which can be around ten thousand volts or higher. This alternative configuration with the grounded core requires that the transformer be constructed with additional space between the grounded core and non-grounded end of the secondary winding to reduce electric fields that would otherwise lead to transformer failure. As will be appreciated, this can result in a larger stock prod housing. [0009] The high voltage potential in present stock prods can also be generated using a capacitor multiplier circuit. Such circuits can be designed in several ways. A common circuit design uses a step-up transformer to drive the capacitor multiplier circuit where the transformer provides an increase in voltage over the supply voltage and the capacitor multiplier circuit steps up the transformer's output voltage to a high voltage potential. Although the transformer's voltage is lower than the high voltage potential, the transformer in this design may also suffer from the same electric field and leakage current as mentioned above. Alternatively, the circuit design may use transistors to drive the circuit. Unfortunately, the problem with such an arrangement is that without the transformer to provide an increase over the supply voltage, the multiplier circuit requires many more stages resulting in a design that is large and expensive. For this reason, this design is not common in the industry. [0010] A common problem with the aforementioned high voltage generating configurations is that the high voltage can circumvent isolation between the various components and, under certain conditions, present a potential hazard to the operator. For instance, the operator may inadvertently become part of the electrical pathway when grabbing onto and holding a prod housing that is covered with condensation, or by accidentally touching an exposed metallic fastener that is in electrical contact with the power supply or primary circuit of the transformer of the prod, thus electrically connecting the user to the stock prod's power supply or primary circuit. In such not altogether uncommon conditions, should one of the electrode tips be brought into contact with an animal, current can flow out one of the high voltage electrodes, down through the animal, through the soil, up through the operator and back into the prod through the moisture or metallic fastener, and from the transformer's primary winding to secondary winding either through direction connection in the circuit or by arcing from primary winding to secondary winding, shocking the operator in the process. For this reason, some present stock prod enclosures try to provide the user with a layer of insulation to keep the user from becoming electrically connected to the power supply or primary circuit of the transformer. [0011] Initially, electric stock prods were only able to produce one discharge level. However, it soon became apparent that one discharge level was not applicable to all animals. The problem was that some animals might be unaffected by the discharge, while other animals might find the shock intensity very intense. As a result, some of the present stock prods are now provided with a switch to change the shock intensity between two different discharge intensity levels or modes, high and low. Other stock prods are provided with interchangeable circuits or electrical generating components that provide predetermined levels of discharge intensity levels that are geared to the particular animal to be controlled. A drawback with these attempts to control the level of discharge intensity is that they are all preset by design and not adjustable, and the prod is unable to operate at an optimal level for a particular animal. [0012] In addition to the high voltage, some stock prods are provided with an audible sound in an effort to control the animal more humanely. As one may imagine, this combination of a high voltage discharge and an audible sound may consume a relatively large amount of power. In an attempt to reduce such power consumption, some prods are provided with a second switch that can be used turn the high voltage off and conserve battery life. Typically, this second switch is located inside the battery compartment of the housing and is relatively difficult to access. This energy saving, high voltage cutout switch also allows the operator to control animals whose behavior has been modified to respond to the audible sound. However, the problem with this type of prod is that it does not give an operator the option of quickly reactivating the high voltage should a bull or other animal decide to charge. [0013] Existing stock prod housings are manufactured using a variety of plastic materials to support the electrodes. Depending on the distance between the electrodes and the voltage differential therebetween, arcing may occur, and this often results in a layer of carbon being deposited across the housing surface. This carbon can cause the stock prod to short-out and stop providing a shock to an animal. One solution to this problem is to increase the space between the electrodes. Another solution to this problem is to reduce the voltage. The problem with these solutions is that they either increase size or reduce effectiveness and do not address the cause of carbon tracking, allowing the problem to reoccur. [0014] There is a need for an electric prod that is able to extend battery life, while maintaining its effectiveness of operation. There is also a need for an electric prod that is less prone to accidental user shock, and transformer failure. There is yet another need for a stock prod that is able to maintain a predetermined output in the presence of different power supplies. There is also a need for a prod whose output intensity may be adjusted to a particular situation or a prod whose output self-adjusts to the situation. There is yet another need for a prod whose operational status is readily observable. There is still another need for prod that is able to provide two levels of animal control cues while the prod is in operation. And there is a need for a prod whose electrodes are less prone to short-circuiting. SUMMARY OF THE INVENTION [0015] Briefly, the present invention comprises an electric stock prod of the type that controls or modifies animal behavior through the use of multiple control cues, such as audible sounds and electrical discharges. The prod comprises a power module (or motor) having an input section, an output section, and a multi-functional control circuit. The input section of the power module (or motor) is operatively connected to a suitable power source and the output section of the power module is operatively connected to a pair of discharge electrodes. The power module is provided with a protective shell, which is positioned and secured within a prod housing. The power source may comprise one or more batteries, a battery pack, a fuel cell, or even a self-contained modular power unit, for example, and be positioned and secured within the prod housing or releasably attached to thereto, as the case may be. It will be appreciated that the output of the aforementioned power sources will vary in terms of operational voltage and impedance, and for that reason the prod of the present invention is provided with circuitry that is able to monitor the power source and control the output so that the prod can ultimately provide a consistent shock intensity. The circuitry also has the ability to assess the condition of the power source and transmit this information to the operator. A feature of the circuitry is that it is able to conserve power source life and still administer an effective electrical discharge to an animal. The intensity level of the electrical discharge can be further adjusted to take into account factors inherent to the animal being controlled, and/or external factors such as weather. Preferably, the prod is provided with a two-step trigger switch that is able to provide two control cues (an audio cue, and an electrical discharge cue) which are used to condition an animal and which also conserve energy. High voltage potentials are achieved through the use of a step-up transformer that is configured so that the potential for accidentally shocking the operator is greatly reduced. [0016] More specifically, the stock prod of the present invention provides longer power source life by modifying the discharge of the prod without diminishing its effectiveness. This is achieved by forming each discharge into a series of short pulse trains instead of one long continuous pulse train or oscillations, and its operation may be described thusly: a short pulse train, then a pause with no pulses, then another short pulse train, then another pause with no pulses, and-so-on. Preferably, each of the shorter pulse trains has the same energy level per pulse and the same pulse rate as the longer continuous output. However, this can change depending on how the circuitry is programmed or configured. The benefits of having such a discharge are twofold. First, the prod is able to deliver a discharge that is as effective as a long pulse train. And second, by providing periods of acquiescence between the short pulse trains, power source life is prolonged. It will be appreciated that the parameters of operation such as energy level, pulse rate, periods of acquiescence between the pulses, etc. are values that may be programmed or otherwise incorporated into the circuitry design. [0017] The step-up transformer of the present invention differs from prior art stock prods in that it has two secondary windings rather than one secondary winding. With this configuration, the two secondary windings are connected to each other in series, with one end of each winding connected as a center tap, which is connected to the transformer core. By using two secondary windings in series the voltage potential between the transformer's secondary winding can be halved, relative to the core. Thus, instead of having a ten thousand volt differential between a single secondary winding and the core, there are two voltage differentials of plus and minus five thousand volts between each of the two secondary windings and the core. Note that the voltage differential between those ends of the secondary windings not connected to the center tap would be equal to the output potential of the prod, in this example, ten thousand volts. This configuration allows the distance between the core and the windings to be reduced, resulting in a smaller, lighter, and less expensive transformer. [0018] Another feature of the step-up transformer is that it also has an isolation value that has a higher value than the output voltage. By increasing the primary to secondary isolation such that the isolation is greater than the output voltage of the prod, the output voltage is prevented from jumping from the primary to the secondary winding to complete the circuit through an operator. This virtually eliminates any shock through an operator and the circuitry even if the operator is directly or indirectly in contact with the power source. [0019] The circuitry of the prod performs several functions, one of which is to monitor the output of the power source. In operation, the circuitry compares the output of the power source with one or more predetermined values. Then depending on the degree of difference between the monitored and predetermined values, the circuitry will activate an indicator. For example, if the circuitry detects a level of supply current in the normal operating range, it will provide a signal to the operator of the prod. If the circuitry detects a level of supply current that is slightly below the normal operating range, but still able to produce an effective output, it will provide a different signal to the operator of the prod. And, if the circuitry detects a level of supply current that causes the output falls below a minimum threshold, it will provide yet another different signal. Thus the operator of the prod will be able to determine, in advance of use, if the power source needs to be immediately replaced or needs to be replaced in the near future. Preferably, the indicators are visually discernable when activated. However, it will be appreciated that they may produce sounds when activated, for example, pre-recorded messages, or tones. [0020] Another function performed by the circuitry is to control the output or shock intensity. This is achieved using two different methods each independent from each another. In the first method, control is achieved by measuring the supply voltage of the power source to determine operational values. It will be appreciated that the operational values determine the output parameters of the output, such as voltage, number of pulses per second, and duration of pulse trains and duration between pulse trains. For example, four C-cell batteries combined to generate an output voltage of six volts will have a set of operational parameters different than the operational parameters for six C-cell batteries combined to generate an output voltage of nine volts. In each case, the combination of operational parameters and supply voltage will result in the same output parameters such as voltage, number of pulses per second, etc. [0021] The second method to control the output or shock intensity is by measuring the supply current and comparing it to operational values that may be predetermined or generated according to the supply voltage. If there are differences between the measured and predetermined values, the output level of the power source is adjusted to bring it into accord with the predetermined value. For example, the circuit draws a given amount of current. The circuitry is designed so that it is able to measure this current draw and compare it to a predetermined value, say one amp, and adjust the output accordingly. Note that the operational values may be designed into, pre-programmed, or generated on a real-time basis by the circuitry as it measures the voltage value. As will be appreciated, this allows the prod to able to accommodate variations in power source impedance due to changes in temperature, changes in power source capacity, or with differences in impedances that occur in different brands of power sources, for example; without any appreciable change in performance. It also allows the prod to operate with different power sources having a range of operational voltages such as one or more batteries, a battery pack, or even a modular power unit having its own protective housing. [0022] Additionally, the prod of the present invention is provided with a separate output adjuster with which to further vary the output level of the discharge. This gives an operator more control over the intensity of the shock that is delivered to an animal. Preferably, the variable output is achieved by providing the circuitry of the prod with a potentiometer. Thus, the prod is able to provide a range of shock intensity levels. [0023] Advantageously, the stock prod is configured to be able to provide two distinct modes of operation. In the first mode, the stock prod will emit an audio cue. In the second mode, the stock prod will emit an audio cue and administer an electrical discharge. Thus, an operator can administer two types of control cues to an animal. In use, the operator of a prod will initially actuate the first mode of operation and then later progress to the second mode of operation so that an animal will receive an innocuous audio cue, and if necessary, an electrical discharge cue. As will be appreciated, actuating the two control cues may be accomplished in a number of ways and with a number of different switching arrangements, such as two separate switches or a single toggle switch. Preferably, however, the two modes of operation are controlled through one multi-step switch. And preferably, this multi-step switch is in the form of a two-step trigger switch. In order to activate the “audio only” first mode, the operator need only partially depress the trigger by a predetermined amount of movement. Note that in this mode, there will be no electrical discharge and this conserves battery life. In order to activate the second mode, which includes both audio and electrical cues, the trigger has to be depressed by a second, predetermined amount of movement. [0024] Another feature of the present invention is that a portion of the power module housing between the discharge electrodes is provided with material that resists carbon tracking that would otherwise result in a carbon track and premature failure. Preferably, the material is polypropylene, and preferably the polypropylene is formed as a unitary structure such as an end cap, which receives and positions the discharge electrodes in a predetermined relation. It will be appreciated, however, that the polypropylene may take the form of a protective layer that is applied or attached to an end cap in a conventional manner. [0025] Accordingly, an object of the present invention is to provide an electrically powered hand-held stock prod for controlling the movement and/or behavior of animals. [0026] Another object of the invention is to increase the operational life of a prod without changing the effectiveness of its electrical discharge or shock intensity. [0027] It is another object of the present invention to reduce the potential for user shock. [0028] Yet another object of the invention is to facilitate determination of the operational status of a stock prod. [0029] A feature of the present invention is that the input is monitored to control the output. [0030] Another feature of the invention is that the prod may be powered by a variety of different sources having a range of voltage potentials. [0031] Yet another feature of the present invention is that the operator may vary the shock intensity within a range of predetermined values. [0032] Yet another feature of the present invention is that the shock intensity may be varied within a range of predetermined values by the control circuitry. [0033] Still another feature of the invention is that the operational status of a prod may be visually ascertained. [0034] Still another feature of the present invention is the ability to provide different levels and types of sensory cues for controlling the movement or behavior of animals. [0035] An advantage of the present invention is that a prod is able to operate effectively using different power sources. [0036] Another advantage of the invention is that the output may be tailored to a particular situation. [0037] Still another advantage of the present invention is that a user can tell, at a glance, the operational status of a prod. [0038] These and other objects, features and advantages of the present invention will become apparent from the following detailed description thereof taken in conjunction with the accompanying drawing, wherein like reference numerals designate like elements throughout the several views. BRIEF DESCRIPTION OF THE DRAWINGS [0039] [0039]FIG. 1 is a side plan view of a preferred embodiment of a stock prod; [0040] [0040]FIG. 2 is a top plan view of the stock prod of FIG. 1; [0041] [0041]FIG. 3 is a partial cross-sectional view of the stock prod of FIG. 1 taken along lines 3 - 3 ; [0042] [0042]FIG. 4 is a cross-sectional view of the stock prod of FIG. 2 taken along lines 4 - 4 ; [0043] [0043]FIG. 5 is a partial, exploded perspective view of a preferred housing and housing cover of a power supply for the stock prod of FIG. 1; [0044] [0044]FIG. 6 is an isometric view of a preferred power module for the stock prod of FIG. 1; [0045] [0045]FIG. 7 is an exploded view of the power module of FIG. 5; [0046] [0046]FIG. 8 is a schematic representation of a preferred circuit used in the preferred stock prod of FIG. 1; [0047] [0047]FIG. 9 is a partial top plan view of the circuit board illustrating the location of some of the components of the power module of FIG. 5; and, [0048] [0048]FIG. 10 is a partial, isometric view of a preferred transformer used in the stock prod of FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENT [0049] Referring to FIG. 1, a preferred embodiment of a stock prod 10 is depicted. As can be seen, the stock prod 10 comprises an elongated body 12 having a first end 14 and a second end 16 . The first end 14 of the body 12 is operatively connected to a conventionally configured shaft 30 of the type having an attachment end 32 and a discharge end 34 , with the attachment end 32 includes a base 36 (see FIG. 3) and the discharge end 34 including electrodes 38 , 40 . The shaft 30 is operatively connected to the first end 14 of the body 12 by a ferrule 42 and a nut 44 . The second end 16 of the body 12 is operatively connected to a power supply 50 that comprises a housing 52 having a first end 54 , a second end 56 and a cavity 58 (see FIGS. 3 - 5 ). As can be seen, the first end 54 of the power supply 50 is operatively connected to the second end 16 of the body 12 in a manner that will be discussed later in greater detail. For ease of fabrication, body 12 is formed as housing members 18 , 20 which are removably connectable to each other in a confronting relation and which form an interior space 22 (see FIG. 5) that is configured to retain a power module 130 (see, for example, FIGS. 3, 6 and 7 ). As can be seen in FIG. 2, housing member 18 includes an aperture 88 that is configured to retain a protective lens 90 , which is positioned over a changeable indicator on the power module 130 (FIGS. 3, 6, and 7 ). As will be appreciated lens 90 may be clear or tinted as desired. [0050] Referring to FIG. 3, the second housing member 20 includes a recess 92 and a peripheral wall 94 that are configured to receive a trigger assembly 100 . The trigger assembly 100 comprises a trigger housing 102 and a switch (or trigger) 108 that is pivotally connected to the housing 102 by a pivot pin 110 . The trigger assembly 100 is provided with a biasing element (not shown) that urges the switch 108 towards an off or non-engagement position. The assembly 100 also comprises a plunger 114 that is operatively connected to the switch 108 and which may be moved thereby into the interior 22 (shown in FIG. 5) of the body 12 through apertures 116 , 98 of the housing 102 and body 12 , respectively, so that it may engage an electrical contact 118 (see FIG. 6). Preferably, the trigger assembly 100 is attached to the housing member 20 by a fastener 106 that passes through apertures 96 and 104 of the body 12 and the housing 102 , respectively. The trigger assembly 100 also comprises a trigger lock 120 that is movably connected to the trigger switch 108 by a connecting member such as a pin fastener 122 . In order to lock the trigger switch 108 the trigger lock 120 , which is normally aligned with the trigger switch 108 , is rotated so that it is misaligned relative to the trigger switch 108 . When the trigger lock 120 is rotated in such a manner, the trigger lock is 120 is positioned so that it will contact the walls of the trigger housing 100 and/or the peripheral wall 94 of the housing member 20 . When this occurs, the trigger switch 108 and attached plunger 114 are prevented from moving the contact 118 (see FIG. 6) so that it completes an electrical circuit. [0051] Turning to FIGS. 3 and 4, the shaft 30 is operatively connected to the first end 14 of the body 12 by a ferrule 42 that engages the base 36 of the shaft 30 , and a nut 44 that frictionally and compressively engages the ferrule 42 . Preferably, the nut 44 is threaded so that it may engage an end cap that extends beyond the first end 14 of the body 12 . Note that the electrical conduits of the shaft have been omitted since they do not form a part of this invention. [0052] Referring to FIGS. 3 and 4, and the second end 56 of the housing 52 , note that the exterior surface of the base 60 is designed and configured so that it may support the stock prod 10 in a freestanding relation. As can be seen, the exterior surface of the base 60 is substantially planar. Preferably, the base 60 is provided with a stand-off or rib 62 that further positions the stock prod 10 and which provides clearance for a latch 74 that secures the housing 52 to the body 12 . [0053] Referring to FIGS. 3 and 4, and the first end 54 of the housing 52 , note that the cavity 58 , which retainingly receives batteries B, may be closed off by a housing cover 76 . The cover 76 comprises a circumferential wall 78 that is configured to engage an internally formed ledge 59 in the power supply housing 52 . The cover also comprises resiliently mounted tabs 80 having outwardly extending projections 82 that engage inwardly facing recesses 61 (see FIG. 5) formed in the interior surface of the housing 52 . In an unstressed state, the tabs 80 are arranged so that the outwardly facing projections 82 are in position to engage the recesses 61 in the housing 52 . To disengage or attach the cover 76 to the housing 52 , the tabs 80 and their projections 82 are biased towards each other in a pinching action. Once the pinching action is discontinued, the tabs 80 are free to resume their unstressed state. The cover also comprises an aperture 84 (see FIG. 5) that is configured to accept a central shaft 64 that extends from the second end of the housing 52 . As can be seen, the central shaft 64 extends through the cavity 58 of the housing 52 and through the aperture 84 (see FIG. 5) of the cover 76 , but also partially though an aperture in the body 12 (see also FIG. 6). The central shaft 64 includes a through hole 66 that is configured to slidingly accept a rod 68 . One end of the rod 68 is threaded and provided with a nut 70 . The nut 70 is used to retain a deformable member 72 on the rod 68 so that it is positioned between the top of the end of the central shaft 64 and the nut 70 . The other end of the rod 68 is provided with a pivotly mounted latch 74 . The latch 74 is configured so that when it is aligned with the rod 68 the deformable member 72 is in an unstressed state, and when the latch 74 is pivoted so that it is transverse to the rod 68 the deformable member 72 is compressed and expands radially relative to the central shaft 64 and the aperture in the body 12 (see also, FIG. 6). Note that when the deformable member 72 is in its expanded state, it is larger than the aperture of the body 12 , and withdrawal of the central shaft 64 therefrom is prevented. [0054] Referring to FIG. 5, the juxtaposition of a power supply housing 52 , a housing cover 76 and a body 12 can be seen. Assembly is a follows. A cover 76 is positioned over the first end 54 of the housing 52 . Note that batteries have been omitted from the cavity 58 of the housing 52 to facilitate a better understanding of the figure. The tabs 80 are then moved towards each other in a pinching action and the aperture 84 of the cover 76 is aligned with the central shaft 64 . The cover 76 is then slid over the central shaft 64 until the circumferential wall 78 engages the ledge 59 of the housing. Since the depth of the circumferential wall 78 of the cover 76 is less than the depth of the ledge 59 of the housing 52 , the cover 76 will be recessed relative the edge of the first end 54 . The tabs 80 are then released and the projections 82 are allowed to engage the recesses 61 of the housing. To attach the power supply housing 52 to the body 12 , the first end 54 of the housing is brought into alignment with the second end 16 of the body 12 . The housing 52 and the body 12 are then brought together. As the housing 52 and the body 12 are brought together, offset skirts 24 a , 24 b guide their movements until the housing 52 contacts shoulders 26 a , 26 b of the body. As this occurs, the deformable member 72 of the central shaft 64 protrudes through an attachment aperture in the body (see FIG. 6). After the housing 52 and the body 12 have been joined together, the latch 74 (see FIG. 3) is pivoted so that it is transverse to the rod 68 . This causes the deformable member 72 to expand and prevent the central shaft 64 from being withdrawn from the engagement with the aperture in the body. It will be appreciated that the cover 76 need not be present for the power supply housing 52 to be connected to the body 12 , and that there may be occasions where such a connection will be necessary or desirable. [0055] Referring to FIG. 6, the body 12 (as shown in FIG. 1) is configured to retain a power module 130 comprising a shell 132 having opposing helves 134 , 136 (see FIG. 7). The shell 132 has a first end 138 and a second end 140 . The second end 140 comprises an aperture 144 that is configured to admit the nut 70 and the deformable member 72 of the central shaft 64 that extends from the base 60 of the power supply housing 52 . The second end 140 also comprises a second aperture 142 that is configured to permit manipulation of an output adjustment member. The second end 140 also comprises an input section 146 which operatively connects to the power supply 50 through the electrical interface 86 (see FIG. 5) of the housing cover 76 of the power supply housing 52 . As will be seen, the input section 146 distributes power to several areas of the power module 130 . Continuing on, the first end 138 comprises a threaded end cap 150 that forms a portion of the output section 152 , which partially extends from the shell 132 . [0056] Referring to FIG. 7, the shell halves 134 , 136 have been separated to reveal internal components of the power module 130 . As can be seen, the shell halves 134 , 136 form an aperture 154 at the first end 138 that receives the end cap 150 . The end cap 150 comprises a plurality of tabs 156 ( a - d ) that are configured to be received in slots 158 ( a - d ) in the shell halves 134 , 136 during assembly of the shell 132 . The end cap 150 includes two apertures 160 , 162 that are configured to receive and retain connectors J 5 , J 4 , respectively, that conduct electricity to the shaft 30 (see also, FIG. 4). The end cap 150 is fabricated from material that resists carbon tracking. Preferably, the material comprises polypropylene. It is understood, however that other material having similar characteristics may also be used. It is also understood that the end cap need not be fabricated as a unitary structure, and that carbon tracking resistant material may be applied to the end cap in a conventional manner using known techniques and technologies. The internal components of the power module 130 are carried on a printed circuit board 170 whose circuitry will be discussed in greater detail below. [0057] Referring to FIGS. 8 and 9, a preferred circuit diagram of a stock prod in accordance with the present invention is shown. The power supply circuit is powered by a suitable direct current power supply, which may be take the form of four to seven batteries providing six to nine volts DC. The circuit is connected to the power supply by through connectors J 1 and J 2 , where J 1 and J 2 are positive and negative, respectively. [0058] Power from the power supply is connected to three sections of the circuit in FIG. 8. First, power is connected to the voltage sense circuit comprised of zener diode D 3 used to create an offset voltage and resistor R 3 B and resistor R 4 C configured in what is commonly referred to as a voltage divider. Voltage at the common point of resistor R 3 B/R 4 C is connected to the control circuit through resistor R 4 B provided as a high impedance between the voltage divider and the control circuit. The voltage sense circuit provides the control circuit with measurable voltage reflective of the power supply voltage. [0059] Second, power is connected to transformer T 1 through diode D 1 and capacitor C 1 . Transformer T 1 is used to generate high voltage and is turned on and off by a transistor Q 1 which is connected to the control circuit. When transformer T 1 is turned on (on-time), current flows through the primary winding storing energy in the transformer's core. When transformer T 1 is turned off (off-time), energy in the core is coupled to the secondary winding of Transformer T 1 creating a high voltage pulse. The on-time and off-time are critical to both the prod's shock intensity and power supply life and are an intricate part of the timing circuit covered later. Current provided to transformer T 1 is provided through diode D 1 , which is used to prevent current flow should the power supply be connected with the incorrect polarity. Current provided to transformer T 1 is also provided through capacitor C 1 , which is used as a filter to provide a more constant current flow from the power supply. [0060] Third, power is connected to the power supply for the control circuit and is comprises a voltage regulator U 1 , capacitors C 2 , C 3 , and C 4 and diode D 2 . Voltage regulator U 1 provides a constant voltage for the control circuit and serves as a reference voltage. Capacitors C 2 , C 3 , and C 4 all provide filtering for electrical noise. Diode D 2 is used to prevent current flow from the power supply to the control circuit should the power supply be connected with the incorrect polarity. The control circuit consists of a single part, micro-controller U 2 . Micro-controller U 2 performs all measurements, provides all timing functions, determines all operating values, and controls functions of the stock prod. When power is applied to the circuit shown in FIG. 8, micro-controller U 2 starts executing it's program and measures the voltage from the voltage sense circuit comprised of Diode D 3 and Resistors R 3 B, R 4 C, and R 4 B through an internal A/D converter connected to pin 6 of Micro-controller U 2 . The voltage measured by micro-controller U 2 at pin 6 is directly related to the supply voltage. The program executed in micro-controller U 2 compares the measured voltage to predetermined values to determine the voltage of the power source and sets additional operating parameters based on the operating voltage. The step of setting operating parameters for variation in supply voltage allows the stock prod's shock intensity and power supply life to be kept constant regardless of supply voltage. [0061] Once the voltage of the power supply is determined and micro-controller U 2 determines the operating parameters for given supply voltage, micro-controller U 2 executes program code to determine the position of the trigger (or switch, see 108 of FIG. 3). The trigger is provided with three positions. The first position is off with connector J 3 connected to the negative supply contact, connector J 2 . When the trigger is partially pressed, power is applied to the circuit through connector J 2 and J 1 . As the trigger is further pressed to the third position, connector J 3 is disconnected from ground (Connector J 2 ). Micro-controller U 2 measures the voltage on connector J 3 through resistor R 3 A by means of another A/D converter connected to pin 5 . R 3 A is provided to allow micro-controller pin 5 to operate as an output while connector J 3 is connected to ground. If the voltage measured by micro-controller U 2 at pin 5 is connected to ground, the program changes pins 5 and 6 to outputs to drive an annunciator (preferably a buzzer) B 1 . The program remains in a loop measuring the position of the trigger based on the voltage at pin 5 and toggles outputs from pins 3 , 5 , and 6 to create an audio sound from the annunciator (buzzer) B 1 and to create a signal from an indicator of an indicator circuit (wherein the indicator circuit preferably comprises a light emitting diode (LED) D 5 and current limiting resistor R 2 ). When the trigger is fully pressed, the voltage at pin 5 rises above ground allowing micro-controller U 2 to measure the increase in voltage causing the program to move to the section of program code used to generate high voltage at the prod's output connectors J 4 and J 5 . This three-stage trigger allows the user to activate the prod in either audio only or in high voltage modes without the use of a second switch located in an inconvenient location. [0062] Before turning the high voltage on, micro-controller U 2 executes a section of program to determine the output level according to where the user sets the position of an output adjuster (preferably a potentiometer) R 7 . The potentiometer R 7 is connected to ground and in series with resistors R 5 C and R 5 B where resistor R 5 B becomes the upper leg of a voltage divider. Resistors R 7 and R 5 C become the adjustable lower leg of the voltage divider, and common point of the voltage divider (R 5 B and R 5 C) is measured by micro-controller U 2 through the A/D converter connected to pin 5 . Based on the voltage measured by micro-controller U 2 at pin 5 , parameters are determined for the output of the prod. As long as the high voltage is on, micro-controller U 2 will loop back to this section of the program, determine position of potentiometer R 7 , and adjust the parameters for the output based on the position of potentiometer R 7 . [0063] After micro-controller U 2 has executed the section of program to determine the user's desired output level according to the position of the output adjuster R 7 , micro-controller U 2 provides a signal to transistor Q 1 turning current on to the primary winding of transformer T 1 . The gate of transistor Q 1 is also connected through resistor R 3 C to ground to bleed off any gate charge on transistor Q 1 . When transistor Q 1 is turned on and current flows from the positive supply source connected to connector J 1 , through diode D 1 , through the primary winding of transformer T 1 , through transistor Q 1 , and through resistor R 1 to ground connected to connector J 2 . Resistor R 1 is provided in the lower leg of the current path to provide a voltage level that changes relative to ground with the amount of current through the primary winding of transformer T 1 . Resistor R 1 is also provided in parallel with capacitor C 6 provided for noise suppression. As current through transformer T 1 increases during the current pulse, the voltage across resistor R 1 increases. The voltage across resistor R 1 is measured by micro-controller U 2 through another A/D converter located within micro-controller U 2 at pin 7 through Resistor R 4 A. Resistor R 4 A is provided just as in impedance between micro-controller U 2 and the rest of the circuit for purposes of noise rejection. After determining the current through the primary winding of transformer T 1 by means of the voltage across resistor R 1 , micro-controller U 2 compares the current to operating parameters to determine if the current is within limits. If the parameters are not within limits, micro-controller U 2 adjusts the on-time duration to move the current back within limits. This allows the prod to compensate for changes in power supply due to factors such as aging or temperature (ie. old and/or cold batteries). [0064] As micro-controller U 2 determines the supply current by measuring the voltage across resistor R 1 , it also determines if the current can be maintained within limits, maintained out of limits, or inadequate for the prod to deliver an effective output. If the current can be maintained within limits, micro-controller U 2 sets outputs at pins 3 and 5 to turn the indicator on to a predetermined color (ie. turning the LED D 5 on green) to provide a signal to the user that the power source is acceptable. If the current can be maintained but not within limits, micro-controller U 2 sets outputs at pins 3 and 5 to turn the indicator on to a second predetermined color (ie. turning the LED D 5 on yellow) to provide a signal to the user that the power source is weak. If the current is determined to be inadequate to provide an effective output, micro-controller U 2 sets outputs at pins 3 and 5 to turn the indicator on to a third predetermined color (ie. turning the LED D 5 on red) to provide a signal to the user that the power source is unacceptable. This provides the user with immediate feedback regarding the condition of the power source. [0065] Micro-controller U 2 continues executing it's program turning transformer T 1 on and off by transistor Q 1 , while determining the supply current by measuring the voltage across resistor R 1 , determining the user's desired output according to the position of output adjuster (potentiometer) R 7 , controlling the type of signal that the indicator displays to the user through diode D 5 according to the condition of the power source, and adjusting operating parameters, limits, and variables to maintain a constant output. After continuing operation for two seconds, micro-controller U 2 tests pin 4 to determine if it is connected to ground, or if the ground has been removed at the factory where resistor R 5 A connected between micro-controller pin 4 and Vdd pulls pin 4 above ground. If micro-controller U 2 determines pin 4 is connected to ground, the program continues in the same loop described above. If micro-controller U 2 determines pin 4 is no longer connected to ground, transistor Q 1 is turned off and held off until the user releases the trigger and reapplies power causing micro-controller U 2 to restart at the beginning of it's program. This determination of the condition of micro-controller U 2 pin 4 allows the program to operate in more than one mode; for example, when continuous operation is desired, or when operation is stopped after a predetermined period of time (for example, two seconds). [0066] While micro-controller U 2 turns transformer T 1 on and off, off-times are periodically extended creating pulse trains and periods with no output. The shock intensity felt during the pulse train is the same as if no off-time had been extended. Although no shock is felt during the time of the extended off-time, the prod is as effective during the pulse train. This extended off-time reduces the average current draw from the power source, which results in longer power supply life [0067] As the current is turned on and off through the primary winding of transformer T 1 , high voltage pulses are developed on the secondary winding. These pulses are rectified through diode D 4 and stored in capacitor C 5 until the voltage in capacitor C 5 is high enough to break down spark gap JP 1 . Capacitor C 5 is provided with a resistor R 6 in parallel to bleed capacitor C 5 down after power has been removed from the circuit to avoid capacitor C 5 from retaining a charge possibly discharging accidentally several seconds after the user releases the trigger. When the voltage in capacitor C 5 breaks down spark gap JP 1 and when the high voltage connectors J 4 and J 5 are in contact with an animal, the energy in capacitor C 5 discharges through the animal administering the shock. A discharge may also occur when the voltage in capacitor C 5 breaks down spark gap JP 1 and when a path such as a carbon track is provided between connectors J 4 and J 5 . To reduce and/or eliminate the possibility of a carbon track developing, an insulator manufactured of polypropylene, which resists carbon track build up, supports connectors J 4 and J 5 . [0068] In addition to providing the high voltage, transformer T 1 also provides isolation between the power source connected to the primary circuit and the secondary winding connected to the high voltage circuit. The isolation is different from existing stock prod transformers in that the isolation between primary winding and the secondary winding is higher than high voltage potential delivered. This higher level of isolation between primary and secondary winding creates an insulation barrier such that the user is isolated form the high voltage eliminating the possibility of the user receiving a shock through moisture connecting the user to the supply source or primary circuit. [0069] Referring to FIG. 10, transformer T 1 is depicted without windings to better facilitate understanding of the invention. As can be seen the transformer T 1 comprises a generally u-shaped core 180 having legs 182 and 184 . Starting from the left side of the figure, a primary winding connector 188 can be seen. A primary winding bay 190 and a second primary winging connector 192 and one or more isolation members 194 follow this. As mentioned previously, the transformer of the present invention differs from transformers used in prior art stock prods in that it has two secondary windings rather than one secondary winding. Moreover, the secondary windings are connected to each other in series. Thus, the first of the two secondary windings starts with secondary center tap 202 , proceeds to secondary winding bays 200 and 196 , and ends up at negative secondary winding connection 198 . The second of the two secondary windings starts with the secondary center tap 202 , proceeds to a secondary winding bays 204 and 208 and attaches to a positive secondary winding connection 206 . With this configuration, the two secondary windings are connected to each other in series, with one end of each winding connected at a center tap 202 , which is connected to the transformer core 180 . By using two secondary windings in series the voltage potential between the transformer's secondary winding can be halved, relative to the core. [0070] The present invention having thus been described, other modifications, alterations or substitutions may present themselves to those skilled in the art, all of which are within the spirit and scope of the present invention. It is therefore intended that the present invention be limited in scope only by the claims attached below.

An electrical discharge stock prod having a circuit that prolongs battery life by monitoring power input and modifying the prod discharge characteristics. The circuit allows the prod to deliver a consistent voltage level to discharge electrodes, even though the power sources may vary. Preferably, the circuit is operated by a micro-controller. Additionally, by virtue of an improved transformer configuration (which lowers the voltage potential between the primary and secondary cores) and strategically placed polypropylene (which reduces carbon arcing) and increased isolation between primary and secondary windings within the transformer, safety of the prod is substantially enhanced. Preferably, the voltage to the discharge electrodes of the prod can be infinitely adjusted within a predetermined range of voltages, energies, and/or pulse rates to allow the prod to be effectively used on subjects having different physical parameters. Moreover, the prod is provided with a multi-function actuator that is configured to provide the prod with two types of cues; an audible cue, and a combined audible and electrical discharge cue, respectively. The prod includes a visual indicator that lets the operator know, at a glance, if the power supply has sufficient energy to operate the prod. And, the prod includes a removable power unit that includes a base, which enables the prod to be free standing when not in use.

BACKGROUND OF THE INVENTION Field of the Invention The invention relates to a method for monitoring the functional capability of lambda sensors, in which switching times of the lambda sensor are measured. In internal combustion engines, pollutant emissions can be reduced by catalytic post-treatment. A prerequisite of catalytic post-treatment is a certain composition of the exhaust gas, which is known as a stoichiometric mixture. That purpose is served by mixture regulation by means of a so-called lambda sensor, by which the mixture composition is periodically regulated within close limits around a command or setpoint value. To that end, if the fuel/air mixture is rich, the sensor outputs a high voltage (the rich voltage), and if the fuel/air mixture is lean, it outputs a low voltage. A voltage jump that is characteristic for lambda=1 is located between those voltages. The sensors may become defective in the course of operation, causing the mixture composition to be incorrectly regulated. In that case the exhaust gases are no longer correctly detoxified, and over the long term the catalyst is even damaged as a result. It is therefore necessary to monitor the functional capability of the lambda sensor. Summary of the Invention It is accordingly an object of the invention to provide a method for monitoring lambda sensors, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known methods of this general type and which makes it possible to reliably monitor a dynamic functional capability of a lambda sensor. With the foregoing and other objects in view there is provided, in accordance with the invention, a method for monitoring lambda sensors, which comprises ascertaining a reference value from a magnitude of switching times under operating conditions of a lambda regulation cycle, in which a sensor signal changes from a rich value to a lean value or from a lean value to a rich value, and classifying a sensor as functioning correctly if the reference value is less than an associated limit value. This is done by measuring the switching times within which the lambda sensor, in the context of its jump function, switches over from the high voltage value (rich voltage) that characterizes a rich mixture to a lower voltage value (lean voltage) that indicates a lean mixture. The switching times for the reverse jump from "lean" to "rich" are also measured. The magnitude of these switching times is a measure of the functional capability of the lambda sensor. If the switching times are above a limit value ascertained beforehand on a test bench using correct lambda sensors, or if they are equivalent to this limit value, the lambda sensor is defective. If the switching times are below the limit value, then the lambda sensor is functioning correctly. The limit values are dependent on the engine operating point and are therefore taken from a performance graph, for instance as a function of the aspirated air and the rpm of the engine. In order to monitor the switching times, it is necessary for the engine to be in a virtually steady operating state during the test cycle. However, in that state, the testing is possible without disruptively intervening in the lambda regulation. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a method for monitoring lambda sensors, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing. BRIEF DESCRIPTION OF THE DRAWING The drawing is a flow chart which shows the course of an exemplary embodiment of the method according to the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the single FIGURE of the drawing in detail, there is seen an exemplary embodiment in which it is assumed that with a rich mixture, a lambda sensor outputs a higher voltage value than with a lean mixture. The method of the invention functions analogously with lambda sensors which have the opposite relationship between the voltage and the mixture. According to the invention, a reference value is ascertained from lambda sensor switching times. In the exemplary embodiment, a plurality of switching times are added together for that purpose, with a separate evaluation being made of the switching times from rich to lean and from lean to rich, and they are compared with an associated limit value. In a method step S1 a switching time TS that the lambda sensor requires to switch over from rich to lean or from lean to rich, is measured. By way of example, the measurement may be performed with a clocked time counter. At the switchover from rich to lean, the elapsed-time counter remains at zero as long as the lambda sensor signal is above a rich threshold. If it drops below the rich threshold, then the time counter begins to run. It stops again once the lambda sensor signal has dropped below the lean threshold. At the switchover from lean to rich, the elapsed-time counter remains at zero as long as the lambda sensor signal is below the lean threshold. If it rises above the lean threshold, then the time counter begins to run. It stops again when the lambda sensor signal rises above the rich threshold. A predeterminable fraction of the maximum value of the lambda sensor signal is defined as the rich and lean thresholds. For instance, 90% of the maximum value is assumed as the rich threshold, and 10% of the maximum value is assumed as the lean threshold. Instead of the most recent measured individual maximum value or minimum value, it is also possible to use the value obtained through a sliding averaging from the respective last actually measured values. As is indicated in a method step S2, the switchover event is monitored at turning points. A turning point occurs if in the event of switching from rich to lean the actually steadily diminishing lambda sensor signal suddenly becomes larger again, or in the event of switching from lean to rich, the actually steadily increasing lambda sensor signal suddenly becomes smaller again. If a turning point is thus recognized, this switching time is no longer used for evaluation. In a method step S3, monitoring is carried out as to whether or not the engine is in a virtually steady state, that is whether or not the load and rpm have not varied considerably since the last switching time measurement. If such an approximately steady state is not present, then once again the switching time is not used for evaluation. However, if an approximately steady state is indeed present, then in a method step S4 a check is made as to whether or not the sensor is switching from rich to lean, and if so then a jump is made to a step S5, or if it is switching from lean to rich, in which case a jump is made to a step S9. In the method step S5, the currently ascertained switching time TS is added to a sum SFM of the switching times that were already ascertained previously. Then in a method step S6, a switching time limit value FMG is read out from a performance graph, for instance as a function of an aspirated airflow and an rpm of the engine, and is added to a sum SFMG of previously already read-out limit values. In a method step S7, a counter ZF, which indicates the number of switchovers from rich to lean, is incremented by one. In a method step S8, a check is made as to whether or not the value of the counter ZF is less than a predeterminable trip value ZFA that defines the length of the test cycle. If that is the case, then a return is made to the start of the method. However, if the value is greater than or equal to the trip value, then in a method step S14 a check is made as to whether or not the sum of ascertained switching times SFM from rich to lean is less than the limit value SFMG. If so, then in a method step S16 an indication is issued that the lambda sensor is functioning properly. However, if the ascertained total value SFM is greater than or equal to the limit value SFMG, then in a method step S15 an indication is made that the lambda sensor is defective. In both cases, the counters and summands are reset in a method step S17, and then if new monitoring of the lambda sensor is intended to take place, a return to the start of the method is made. Conversely, if it is found in the method step S4 that the sensor is switching from lean to rich, then a jump is made to a method step S9. In the method step S9, the currently ascertained switching time TS is added to the sum SMF of switching times that were already ascertained previously. Then in a method step S10, the switching time limit value MFG is read out from a performance graph, again as a function of the current operating conditions of the engine (for instance from the aspirated air mass and the current rpm), and is added to the total SMFG of previously already read-out limit values. In a method step S11, the counter ZM, which indicates the number of switchovers from rich to lean, is incremented by one. In a method step S12, a check is made as to whether or not the value of the counter ZM is less than a trip value ZMA. If that is the case, then a return is made to the start of the method. However, if the value is greater than or equal to the trip value, then in a method step S13 a check is made as to whether or not the sum of ascertained switching times SMF from lean to rich is less than the limit value SMFG. If so, then as was already described above, in the method step S16 an indication is issued that the lambda sensor is functioning properly. However, if the ascertained total value is greater than or equal to the limit value, then as was already described above, in the method step S15 an indication is made that the lambda sensor is defective. If the lambda sensor is defective, a monitoring of catalyst efficiency, which may possibly be present, is moreover inhibited.

A method for monitoring lambda sensors includes ascertaining a reference value from a magnitude of switching times under operating conditions of a lambda regulation cycle, in which a sensor signal changes from a rich value to a lean value or from a lean value to a rich value. A sensor is classified as functioning correctly if the reference value is less than an associated limit value.

BACKGROUND 1. Field of the Invention This invention relates to processes for selectively separating a mixture of components through sorption and desorption and, more particularly to a novel simulated moving bed apparatus and method whereby the simulated moving bed is created within an uninterrupted sorbent bed by imbedding strategically within such sorbent bed multiple distributors for injection of feedstock and eluent along with multiple collectors for removal of extract and raffinate and to obtain narrower fraction cuts by reducing the time for injecting feedstock and eluent and collecting separated fractions respectively without stopping the percolation of circulating fluid through the sorbent bed which results in significantly reduced bed compaction and flow restriction. 2. The Prior Art The commercial application of column chromatography for the separation of dissolved constituents using suitable sorbents and batch operation has evolved over the years to a level as represented by Yoritomi et al (U.S. Pat. Nos. 4,379,751 and 4,267,054). To achieve a reasonable level of separation the sorbent beds in these systems must be relatively tall. Yoritomi specifies at least 10 meters. At such high bed depths the flow rates through the bed must be relatively low to avoid progressive bed compaction and eventual total blockage to flow. These necessary low flow rates restrict operating capacities which could potentially be available from state of the art, high kinetic separating mediums. The stop and go operation of a batch process as represented by U.S. Pat. No. 4,379,751 also leaves a large part of the separating medium idle in certain parts of the column while feedstock and eluent are added to the column or extract and raffinate fractions are withdrawn. Additionally, the total removal of certain concentration bands from the column liquid as practiced by U.S. Pat. No. 4,379,751 imposes rather sudden changes of concentration gradients which impairs general operating efficiency in terms of osmotic shock on the resin and the need to re-establish this concentration band in subsequent cycles which retards the speed of operation. These impediments have all but eliminated the batch process from consideration for commercial application in column chromatography. The invention of the so-called simulated moving bed process by Broughton et al (U.S. Pat. No. 2,985,589) improves on the batch operation in its most sophisticated form by providing for the continuous circulation of fluids through multiple beds of sorbents. The sorbent beds are arranged as an endless loop with periodic advances to the next sorbent bed within the loop for inlet flows of feedstock and eluent and outlet flows of effluent fractions, respectively. This operation is also referred to as a pseudo moving bed process. One form of commercialization of this process includes discrete multiple sorbent beds vertically stacked on top of each other in the form of a tower as initially proposed by the foregoing reference as well as those of Ishikawa et al (U.S. Pat. No. 4,182,633); Odawara et al (U.S. Pat. No. 4,157,267); Ando et al (U.S. Pat. No. 4,405,455). Another approach is the use of multiple individual columns horizontally arranged as a train with the train operated as an independent closed loop and is taught by Schoenrock et al (U.S. Pat. No. 4,412,866) and Ando et a (U.S. Pat. No. 4,599,115). In the commercial separation of dissolved constituents by chromatography such a the fractionation of fructose from dextrose or the separation of sucrose from highly impure sugar solution such as molasses by ionic exclusion using the so-called simulated moving bed technique, it becomes necessary to establish and maintain a very specific concentration profile. This concentration profile is distributed, as a rule, over four or more sorbent beds as taught by the foregoing references to aid in optimizing the introduction and withdrawal of streams at strategic positions of the closed loop. One or more of these sorbent beds within the endless loop is projected to represent a specific zone which in their most fundamental form are referred to as sorption, displacement, elution and rinse zones, respectively. Continuous circulation of the loop fluid around this endless loop train causes each of the zones to be periodically shifted to the sorbent bed next in line downstream. The objective is t maintain a steady state concentration profile which moves as a wave continuously around the looped train while introducing feedstock and eluent to the train at strategic locations and removing separated fractions from the circulation fluid thereby establishing a continuum. General performance efficiency and steady state operation of the process depend primarily upon the following factors: 1. Accurate control of the correct circulating flow to maintain a steady state profile through the entire loop. 2. Correct selection of influent and effluent cuts. 3. Uniform cross sectional distribution and drainage of fluids entering and leaving the beds, respectively. 4. Uniform cross sectional, downward movement of the circulation fluid through the sorbent beds with avoidance of channeling or net lateral flow. 5. Distinction between hydraulic balance and internally generated pressure through the circulation pumps and separate control for each pressure function. Conventionally the determination and control of the circulation flow rate remains generally undefined and left to speculation or experimentation. The patent of Schoenrock et al refers to a total liquid displacement volume as being given to provide the basis for establishing the circulation flow rate without defining the meaning of that terminology or how one arrives at that value. Other patents are mute on this point and leave the impression that this value is derived through trial and error. Although the teachings of U.S. Pat. No. 4,412,866 are very specific for correcting a given basic circulation flow rate with measured inflow and outflow rates, experience has shown that these corrections are not accurate and ineffective if the basic circulation flow rate is not accurately know.. The foregoing problems reduce the operating efficiency and the need for periodic manual corrections of the circulation flow rate. Because of its dynamic nature the pseudo-moving bed operation of the known prior art generates a continuously changing concentration profile of the dissolved components in the fluid percolating through the sorbent beds in terms of absolute concentration as well as the relative concentration of the dissolved solutes to each other. These systems also teach and practice a continuous inflow of feedstock and eluent and respective outflows of separated fractions throughout the complete cycle This constraint requires compromises for selecting the positions to introduce feedstock and eluent as well as for withdrawing effluent fractions. A constant feedstock and eluent composition is thus introduced into and spread over a continuously changing concentration profile in the circulation fluid while continuously changing effluent concentrations are withdrawn. Such a processing strategy compromises the background concentration profile. Continuous or frequent monitoring of these concentration profiles is therefore essential to bracket the target concentrations for inlet and outlet positions in pseudo-moving bed separator loops to approach optimum operating performance for the system. To overcome this impediment it is common practice to increase the number of sorbent beds within a sorbent bed train and thereby gain access to smaller changes in the concentration gradients and sharper separation. Hence, the generally held conviction that an increasing number of discrete sorbent beds in a sorbent bed train improves the separating efficiency for pseudo moving bed systems. However, multiple bed trains such as the tower trains require a relatively short bed depth of less than 1 meter for each of its vessels to manage an extremely high pressure drop associated with high flow velocities required by multiple bed trains and which are particularly observed in certain parts of such trains. This high pressure drop is as a rule isolated to those beds where high solids concentrations accumulate and where the sorbent medium expands due to the desorbent action. One option to reduce this restriction for large commercial plants is to increase the diameter of the column and reduce the bed depth for each sorbent bed in the sorbent bed train. It is, however, also generally recognized by experts that it becomes increasingly more difficult to maintain the required uniform cross-sectional distribution, uniform cross-sectional collection and uniform cross-sectional downward movement for fluids in pseudo-moving bed sorbent trains as the ratio of sorbent bed diameter to the sorbent particle size increases. Hence, separation performances deteriorate as a rule with increasing column diameter. Because of the recognized restrictions in sorbent bed diameter the need for multiple trains in large commercial installations is associated with greatly increased costs. All these aforementioned impediments are associated with reduced operating efficiency, greatly increased costs, increased control complexity and increased pressure drop restrictions. The various systems proposed and currently in use represent trial and error compromises deviating more or less from the ideal state for achieving the objectives referred to above. I have now discovered the means to approach the ideal state of efficiency and performance at greatly reduced costs, reduced complexity of valving and reduced process control needs. Problems associated with the control of pressures are also virtually eliminated. In view of the foregoing, it would be an advancement in the art to provide a novel, pseudo-moving bed apparatus in a single vessel having the capability to more efficiently utilize the sorption characteristics of the sorbent material in the sorbent bed. It would also be an advancement in the art to provide an apparatus and method for obtaining narrower fraction cuts through the more efficient utilization of the sorption characteristics of the sorption bed through a carefully controlled pseudo moving bed in the sorption bed. It would also be an advancement in the art to provide a sorbent bed with all of the zones for sorption and desorption of the desired constituent from the fluid stream contained in a single, continuous sorbent bed. Such a novel apparatus and method is disclosed and claimed herein. BRIEF SUMMARY AND OBJECTS OF THE INVENTION This invention relates to a novel apparatus and method for obtaining more efficient separation of constituents from a liquid stream through narrower fraction cuts from a simulated moving bed contained in a continuous, uninterrupted sorbent bed. A circulating liquid stream is continuously moved through the sorbent bed in an endless loop while carefully controlled amounts of feedstock and eluent are periodically introduced into the circulating liquid stream in coordination with the withdrawal of separated fractions from the circulating fluid as predetermined by the kinetics of the specific sorbent material. Multiple distributors and collectors provide for the ability to create a simulated moving bed within the single sorbent bed. It is, therefore, the primary object of this invention to provide multiple distributors and collectors with uniform cross-sectional functionality imbedded in the sorbent material contained in a single, uninterrupted bed functionally operating as a simulated, moving bed to balance unavoidable expansion and contraction of sorbent material in the sorbent bed to prevent bed compaction. Another object of this invention is to periodically inject feedstream and eluent in the shortest possible time into the continuously circulating loop fluid at strategic positions and in coordination with the withdrawal of separated fractions for maintaining hydraulic integrity within the loop to provide for narrower fraction cuts. Another object of this invention is to maintain fixed positions for inlet and outlet streams of the loop. Another object of this invention is to alternate feed and eluent addition in coordination with respective withdrawal of separated fraction. Another object of this invention is to add feedstream and eluent simultaneously to the circulating fluid of the simulated moving bed with uninterrupted, stationary sorbent bed, at fixed locations in coordination with the withdrawal of separated fractions from the circulating fluid. Another object of this invention is to move addition and withdrawal positions along the length of the sorbent bed in coordination with the movement of the optimum concentration profile in the multiple zones within the circulating fluid flowing through the stationary sorbent bed. These and other objects and features of the present invention will become more readily apparent from the following description in which preferred and other embodiments of the invention have been set forth in conjunction with the accompanying drawing and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic of a first preferred embodiment of the novel process of this invention; FIG. 2 is a chart of the circulation liquid profile through the apparatus and method of this invention; FIG. 3 is a schematic of a second preferred embodiment of the novel process of this invention; and FIG. 4 is a schematic of a third preferred embodiment of the novel process of this invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention is best understood by the following description with reference to the drawings wherein like parts are designated by like numerals throughout. General Discussion Through careful observation I have discovered that improved operating performance of pseudo-moving bed processes with increasing number of sorbent beds is largely a result of narrower fraction cuts and increased frequency for collecting and redistributing the circulating fluid through a continuous multiple bed sorbent train with discrete sorption beds. This approach inhibits, through frequent cross-sectional drainage and redistribution, the possibility of progressive channeling and lateral flow which otherwise would distort the moving front and the profile. Such flow deviations occur when moving sorbent bed fluid through a continuous sorbent bed with a large diameter and without special provisions for uniform perpendicular flow, distribution and drainage respectively. This invention comprises an improved pseudo-moving bed system wherein a continuous sorbent bed configured from a single, uninterrupted sorbent bed without the need for multiple beds in the form of discrete compartments or separate vessels. The sorbent bed is characterized in that it contains all concentration gradients within the circulating fluid of a pseudo-moving bed train. The single column eliminates the problem of pressure drop found in sorbent beds where the discrete zones are isolated in separate vessels or compartments within the vessel. This I have found to be important because of the nature of the sorption process as it effects the physical characteristics of the sorbent material. In particular, during the sorption process the individual beads of sorbent material shrink in size while those beads of sorbent material undergoing desorption tend to swell. This latter swelling phenomena causes significant compaction in a sorbent bed confined in a single vessel or compartment with a corresponding reduction of flow rate through the sorbent bed. However, the sorbent bed of my invention is contained in a single vessel with the discrete zones able to freely communicate throughout the entire length of the sorbent bed. This is important since it eliminates the foregoing problem of compaction that would otherwise occur if the various zones in the sorbent bed of my invention were confined in separate compartments. The circulating fluid is continuously moving without interruption through the sorbent bed from the top to the bottom and returned to the top of the sorbent bed by means of a circulating pump to form an endless loop. Collectors are located at strategic positions in the sorbent bed to uniformly introduce feedstock and/or eluent over the entire cross-sectional are of the sorbent bed. Collectors are also located at strategic locations to uniformly withdraw fractions containing separated components from the circulating fluid over the cross-sectional area of the sorbent bed. The introduction of feedstock and eluent to the circulating fluid and the withdrawal of respective fractions from the circulating fluid occur periodically within the shortest possible time whenever the relevant concentration gradient within the circulation fluid arrives at the respective distributors/collectors. Uniform perpendicular and downward movement of circulating fluid is maintained throughout the entire sorbent bed at predetermined, changeable flow rates. Only a portion of the circulating fluid containing the desired concentration gradient is periodically withdrawn at the preselected location. An equivalent volume of feedstock and/or eluent is added to the circulating fluid at the preselected locations while the remaining part of the circulating fluid (plus added feedstock and eluent after becoming part of the circulating fluid) continues its downward travel through the sorbent bed. The circulating fluid passes from top to bottom through the sorbent bed and back to the top to form an endless loop. This circulating fluid maintains a steady state, continuously moving fluid stream but with an unchanging yet dynamically moving concentration profile generated through the progressive and continuous sorption and desorption of sorbents. Collectors and distributors in this sorbent bed system are designed to achieve uniform, cross-sectional distribution of feedstock and eluent and collection of the respective fractions without removal of separating medium from the sorbent bed. These distributors/collectors may be operated in a static, fixed position for a dedicated function. Alternatively, they may be operated dynamically wherein they alternately function in each respective position for distribution or collection. The interior of the sorbent bed columns contain means to enforce uniform cross-sectional and perpendicular downflow without lateral movement for the circulating fluid. This new concept can also be applied to multiple sorbent bed trains in connection with chromatography, ion exclusion, ion exchange or any separation process requiring sorbent beds. In studying the operational limitations of the pseudo-moving bed process I have also discovered the fundamental means for projecting an accurate basic circulation flow and for predicting and maintaining a steady state progressive movement of the four basic zones in a pseudo-moving sorbent bed. I found this to be based on the true liquid voidage between the solid sorbent particles in the noncompressible sorbent bed and the application of the specific kinetics for the sorbent medium. These values can be experimentally determined for each specific sorbent medium and column design. For spherical, uniform particles with a mean diameter of about 320 microns I have determined the voidage to be about 48% of the total sorbent bed volume in columns designed according to this invention and used in ion exclusion operations. I have also determined experimentally the basic kinetics of the sorbent required for predicting the movements of the various zones through a pseudo-moving sorbent bed to assure depletion of the circulation fluid from the sorbed substance and regeneration of the sorbent with the eluent. These functions are defined within the scope of this invention as: a. The ability to retain a fixed quantity of the sorbed component. For the conditions used in this demonstration this value was 31 grams sucrose/liter sorbent medium. b. The average rate of sorption from the blended mixture For the conditions in the examples given below it was to be 1.5 grams/liter sorbent/minute with a range between 0.5 to about 3.5 grams sucrose/minute/liter sorbent medium. c. The average rate of desorption from the sorbent medium loaded with sucrose. The desorption rate for the sorbent medium and conditions in this demonstration it was to be 3.05 grams sucrose per minute per liter sorbent medium with a range between over 7 grams to under 1 grams sucrose/minute/liter sorbent medium. Desorption is primarily driven by concentration differences. With this information it is now possible to project correctly the amount of loading per time unit and the maximum velocity of the circulation fluid during the sorption and desorption process in the sorbent bed to move the optimum concentration profile at steady state and in the proper time frame in front of respective distributors and collectors while keeping respective frontal zones separated from each other. Detailed Description FIG. 1 illustrates the essential components required for a first preferred embodiment of the simulated moving bed according to this invention shown generally at 10 and includes a column 12, having an eluent dome 13, a sorbent bed 14, a circulation distributor 16, a secondary distributor 17, an effluent collector 18, and a circulation collector 19. Also included are a circulation pump 20, a feedstock valve 22, eluent valves 24 and 25, an extract valve 26, a raffinate valve 27, a circulation flowmeter 30, feedstock flowmeter 32, eluent flowmeter 34, effluent flowmeter 35, check valve 36 and pressure sensors 40-43. Special means for preventing lateral flow within the sorbent bed and for enforcing uniform distribution and collection are not shown. FIG. 1 provides for the operation of distributors 16 and 17 along with collectors 18 and 19 in a static mode, each with a dedicated, single function of injection with alternate withdrawal of separated fractions. Sorbent bed 14 is operated as a pseudo-moving bed system within column 12 which is configured as a single column containing sorbent bed 14 as a continuous sorbent bed. The top of sorbent bed 14 may be confined either by a flat, horizontal enclosure of the column (not shown) or by a hydraulic dome or eluent dome 13 formed from the incoming eluent, eluent 45, which in turn is confined by the dished head of the column enclosure of eluent dome 13 as shown in FIG. 1. In the preferred, less costly latter case eluent 45 is added to the top of eluent dome 13 whenever the scheduled addition for eluent 45 at that position occurs. Eluent 45 hydraulically and uniformly pushes the underlying interface into the circulating fluid throughout the cross section of column 12. The circulating fluid is also continuously and uniformly injected through distributor 16 across the cross section of sorbent bed 14. When operating with a flat horizontal top enclosure (not shown) for sorbent bed 14, the top eluent injection through valve 25 would be adjacent to injection of feedstock 44. FIG. 2 illustrates an optimum concentration profile throughout the circulation fluid in sorbent bed 14 (FIG. 1). This concentration profile is generated and maintained when operating at steady state according to this invention. With the lowest solids concentration in the circulation fluid represented by Zone A in FIG. 1 (at circulation distributor 16) eluent 45 is added to eluent dome 13 during a brief period while Zone D, representing the leading front of the nonsorbed components, is moving across collector 18. During this brief period of eluent 45 addition to the top of sorbent bed 14 the most favorable raffinate 47 fraction located in Zone D and containing the nonsorbed component is withdrawn through collector 18 and valve 27. At the same time Zone B contains the desorbed fraction and a concentration gradient equivalent to the feedstock is represented by Zone C. Circulation pump 20 is manipulated to move the concentration profile as illustrated in FIG. 2 without interruption around this endless loop in harmony with the brief periods of additions to and withdrawals from the endless loop while sorption and desorption i continuously proceeding in various parts of sorbent bed 14. This manipulation of the circulation pump 20 moves in due time the most favorable concentration for the desorbed component in Zone B in front of collector 18 while the feed stock 44 concentration profile arrives with Zone C at the circulation distributor 16 and the lowest total dissolved solids concentration in Zone A surrounds the secondary distributor 17. At that point and for the shortest possible time feedstock 44 is added through valve 22 to the circulation fluid in Zone C while the desorbed component, extract 46, is withdrawn through collector 18 and valve 26. Simultaneous with the withdrawal of extract 46 through collector 18 and valve 26 eluent 45 may be added through valve 24 and secondary distributor 17 to Zone A at a preselected rate to maintain the predetermined overall ratio of eluent 45 to feedstock 44 for a complete cycle along with the desired ratio of the separated fractions to each other for a complete cycle. The operation of pump 20 is continuous but variable to move circulating fluid through circulation circuit 21 at a predetermined but changeable rate through the sorbent bed 14 and to maintain a progressive concentration profile at steady state for a total utilization of all sorbent medium in sorbent bed 14 in harmony with the kinetic properties of the sorbent material. FIG. 3 demonstrates the manifolding according to this invention for a single sorbent bed featuring dedicated operation of distributors/collectors but with simultaneous injection of feedstock and eluent to the circulation fluid for the shortest possible time while at the same time withdrawing separated fractions from the circulation fluid through dedicated collectors. The circulation flow is maintained uninterrupted but at a somewhat reduced rate during the short injection period. In its most basic form the configuration in FIG. 3 according to this invention is shown generally at 50 and includes a vessel 52 with a sorbent bed 54. The upper end of vessel 52 is configured with an eluent dome 56. Also included are an upper circulation distributor 60, extract collector 61, feedstock distributor 62, raffinate collector 63, recirculation collector 64, recirculation pump 85, eluent valve 67, extract valve 75, feedstock valve 71, raffinate valve 81, eluent flowmeter 68, extract flowmeter 76, feedstock flowmeter 72, raffinate flowmeter 82, recirculation flowmeter 88, pressure sensors 90-93, and optional outlet valve 69, for backwashing purposes. Recirculation circuit 84 is provided and includes pump 85, pressure gauges 91 and 92, and flowmeter 88 to monitor the flow therethrough. Recirculation liquid is withdrawn from vessel 52 through recirculation collector 64 and returned to vessel 52 through circulation distributor 60. FIG. 3 illustrates operation with an eluent dome 56 but may be configured with a flat horizontal column top (not shown) without freeboard over the sorbent bed in which case the eluent injection is projected to be in the recirculation circuit 84. The top of sorbent bed 54 may be confined either by a flat, horizontal top (not shown) on vessel 52 or by a hydraulic dome formed as eluent dome 56 which in turn is confined by the upwardly dished head of vessel 52 as shown in FIG. 3. In the preferred, less costly latter case eluent 66 is added to the top of eluent dome 56 whenever the scheduled addition for eluent 66 at that position occurs. Eluent 66 in eluent dome 5 hydraulically pushes the eluent dome interface uniformly throughout its cross-sectional area into the circulating liquid. Circulating liquid from recirculation circuit 84 is continuously injected uniformly into sorbent bed 54 across the cross-section defined by the upper distributor 60. Referring now to FIG. 4, a third preferred embodiment of the concentration apparatus of this invention is shown generally at 100 and includes a vessel 102 having a sorbent bed 104 therein. A plurality of distributor/collectors are interposed across the cross-sectional area of sorbent bed 104 at preselected locations along the longitudinal axis of sorbent bed 104. An upper distributor 106 is placed on the upper surface of sorbent bed 104. Collectors 110, 112, 114 and 116 are uniformly spaced throughout the length of sorbent bed 104 with collector 116 located at the bottom of sorbent bed 104. Collectors 110, 112 and 114 simultaneously serve as distributors. However, for sake of clarity and to facilitate the discussion of their function, these distributors are shown separately and are described as distributors 111, 113 and 115, respectively. A recirculation circuit 120 includes a pump 122, pressure gauges 124 and 125 along with a flowmeter 126. Feedstock 130 enters the circulatory system of apparatus 100 through a flowmeter 129, and the flow thereto regulated by the selective operation of valves 131-134 in cooperation with valves 142 and 144 which also control portions of eluent 140. For example, feedstock 130 is directed to distributor 111 by opening valve 133 while valves 132, 134, 131 and 142 are closed. To direct feedstock 130 into distributor 113, valve 131 is opened while valves 133, 144, 132 and 134 are closed. Similarly, feedstock 130 is directed into distributor 115 by opening valve 132 with valves 131, 133, 134 and 143 closed. Feedstock 130 can also be diverted into the recirculation circuit 120 by opening valve 134 with valves 132, 131, 133 and 141 closed. Feedstock 130 is introduced into recirculation circuit 120 upstream of pump 122 in order to assure thorough mixing of the two streams as they pass through pump 122. Eluent 140 passes through flowmeter 139 and is then directed to any one of eluent dome 103 or distributors 111, 113 or 115. Eluent 140 is directed into eluent dome 103 by opening valve 141 while keeping valves 142, 144 and 143 closed. Eluent 140 is directed into distributor 111 by opening valve 142 while keeping valves 141, 133, 144 and 143 closed. Correspondingly, eluent 140 is directed into distributor 113 by opening valve 144 with valves 141, 142, 143 and 131 closed. Eluent 140 is directed into distributor 115 by opening valve 143 and keeping valves 141, 142, 144 and 132 closed. Extract 150 is removed through flowmeter 149 and can be obtained from any one of collectors 110, 112, 114 or 116. From collector 110, extract 150 is removed by opening valve 151 while closing valves 163, 152, 153 and 155. Removal of extract 150 from collector 112 is accomplished by opening valve 152 while closing valves 164, 151, 153 and 155. From collector 114, extract 150 is removed by opening valve 153 while closing valves 161, 151, 152 and 155. Extract 150 is removed from collector 116 by opening valve 155 while closing valves 162, 153, 152 and 151. Raffinate 160 is removed through flowmeter 159 from any one of collectors 110, 112, 114 or 116. From collector 110, raffinate 160 is removed by opening valve 163 while closing valves 164, 151, 161 and 162. Raffinate 160 is withdrawn from collector 112 by opening valve 164 while closing valves 163, 152, 161 and 162. Raffinate 160 is removed from collector 114 by opening valve 161 while closing valves 153, 162, 163 and 164. Raffinate 160 is removed from collector 116 by opening valve 162 while closing valves 155, 161, 163 and 164. FIG. 4 comprises the required components according to this invention when operating a single, continuous sorbent bed functioning with dynamic sequencing wherein injections of feedstock and eluent to the circulation fluid and withdrawals of separated fractions from the circulation fluid occur simultaneously within a short period of time from distributors/collectors which progressively change in their respective function. As the profile according to FIG. 2 in the circulation fluid moves continuously at steady state through the sorbent bed the respective injections of eluent and feedstock to the circulation fluid and the withdrawal of separated fractions from the circulation fluid occurs approximately simultaneous through assigned distributions/collectors for a brief period whenever the relevant concentration front travels across the relevant distributor/collector while the circulation fluid continuous downstream. Relevant inlet and outlet valves are opened approximately simultaneously at that time to allow injection of eluent and feedstock through preselected distributors together with the withdrawal of an equivalent portion of the circulation fluid from preselected collectors respectively while the remaining circulating flow continuous uninterrupted but at a somewhat reduced rate during the injection period. The improvements are applicable to any form of pseudo moving bed separation. Any suitable sorbent material may be used but the preferred material is a uniform, spherical, gel type, noncompressible polystyrenic cation exchanger crosslinked with 6-8% divinylbenzene, a particle size of under 400 microns with a coefficient for particle size variation of less than 10. Variations in the kinetic nature and physical configuration of the sorbent medium will have a decisive impact on the basic circulation flow rate required to maintain a steady state profile. Any suitable sorbents may be used in combination with this invention by adjusting the basic circulation flow, loading and other operating parameters to the specific kinetics, particle size and particle size distribution of the sorbent medium used. When used in ion exclusion such as for the recovery of sucrose from low sugar purity liquors the sorbent medium should preferably be in its ionic potassium form. When used for the chromatographic separation of fructose from fructose/glucose blends the sorbent medium should preferably be in its ionic calcium form. With suitable sorbents the improvements according to this invention may be applied wherever it becomes necessary to separate mixtures into individual components or groups of components. The technique may also be extended to improve the efficiency in ion exchange operations as well. The following examples ar given to detail the procedure according to this invention for the fractionation of sucrose from impure sugar solutions such as final molasses having sugar purities of about 60% on total dissolved solids or mother liquors from the second crystallization stage of sugar beet liquors with a sugar purity of about 75% on total dissolved solids. Total dissolved solids for the feed syrup is preferably as high as possible but is usually held for practical reasons in the range between 60-75%. Operating temperatures should be sufficiently high to minimize the negative impact of viscosity on pressure drop without significant thermal degradation on system components which suggests a range between 65-85 degrees Celsius. Operating capacities depend somewhat on the sugar purity of the feed syrup and may vary between less than 500 kg to over 700 kg total dissolved solids per cubic meter sorbent medium per day for ion exclusion work. Other conditions imposed on the operation include the ratio of eluent to feed syrup and the raffinate to extract ratio. The sorbent medium in the first example is a polystyrenic gel type cation exchanger in the potassium form, crosslinked with 6% divinylbenzene having a mean particle size of 320 microns with a coefficient of variation for particle size distribution of less than 10. Feed syrup in the first example is the mother liquor from a beet sugar crystallization with a sugar purity of 75% of total dissolved solids, a total dissolved solids content of 70% and a temperature of 80 degrees Celsius for both the feed syrup and the eluent. Feed syrup and eluent are both free of suspended solids which could foul the sorbent bed and contain less than 1% multivalent cations on total cations to prevent fouling of the functional groups. Substantial variations from these conditions may be practiced as long as the operating parameters are stable within narrow tolerances throughout each specific operation. EXAMPLE 1 Pseudo-moving Bed Operation with a Single Sorbent Bed, Fixed Distributor Functions and Alternate Injection of Feed Syrup and Eluent and Withdrawal of Separated Fractions in a Short Period of Time (FIG. 1) A vertical column, vessel 12, with an inside diameter of 50 centimeters and height of 490 centimeters was designed as diagrammatically illustrated in FIG. 1. Vessel 12 was uniformly packed with the sorbent medium described above to form sorbent bed 14. Condensate water which was free of dissolved or suspended gases was used as a slurrying agent to transfer the resin until sorbent bed 14 became a noncompressible, uniformly packed sorbent bed that extended from collector 19 to distributor 16. Under these conditions the space occupied by the free water between the sorbent particles represented about 48% of sorbent bed 14 which is the displacement volume in a complete cycle for the movement of the excluded ions and represents the product of circulation flow and total cycle time. The packed column of sorbent bed 14 was first brought to a steady state condition (as reflected by a concentration profile similar to that shown in FIG. 2) by following a series of consecutive steps 1 through 4, outlined below. That profile is than retained and moved continuously through the sorbent bed at steady state by continued cycling of steps 1 through 4. Step 1: Injecting Eluent and Withdrawing Raffinate During Continued Circulation Step 1 is arbitrarily defined with the nonsorbed components in Zone D with the most desirable raffinate concentration profile surrounding collector 18 while the condition in Zone A of circulation liquid nearly void of dissolved solids arrives at distributor 16. At this point eluent is introduced through control valve 25 at a flow rate of 17.8 liters per minute for 5 minutes to move eluent liquid uniformly over the entire cross-section of sorbent bed 14 through the interface at distributor 16 while raffinate is withdrawn simultaneously through collector 18 and control valve 27 at an equivalent rate to maintain steady state pressure at the suction of pump 20 as shown by pressure gauge 42. The circulation flow rate as measured at flowmeter 30 is maintained at about 4.4 liters per minute during step 1 by manipulating pump 20. Step 2: Recycle At the termination of step 1, control valves 25 and 27 close and a circulation flow of 18.0 liter/minute as measured by flowmeter 30 is maintained during step 2 for a period of about 10 minutes or until the desired extract concentration profile in Zone B surrounds collector 18. A minimum total dissolved solids concentration surrounds distributor 17 in Zone A and a purity equivalent to the feedstock surrounds distributor 16 in Zone C. Step 3: Injecting Blend and Withdrawing Extract During Continued Circulation Termination of step 2 and the beginning of step 3 is initiated when the optimum extract concentration in Zone B of the circulation liquid arrives at distributor 18, minimum total dissolved solids are measured in Zone A at distributor 17 and feedstock purity in Zone C surrounds distributor 16. At this point and for a period of 3 minutes feed stock 44 is injected into the circulation liquid at a rate of 5.3 liters per minute through control valve 22 and distributor 16, eluent is injected via control valve 24 and distributor 17 at a rate of 2.1 liters per minute and extract 26 is simultaneously withdrawn via collector 18 and control valve 26 at a rate of about 7.4 liters per minute as measured by flow meter 35. This rate is sufficient to maintain suction pressure for pump 20 at its predetermined level. The recycle flowrate through recirculation circuit 24 during step 3 is maintained at 15 liters per minute. Step 4: Recycle At the termination of step 3, control valves 24 and 22 close and the recycle flow rate is increased to 18 liters per minute as measured at flowmeter 30 for a period of 12 minutes or a condition which returns the imaginary zones in sorbent bed 14 to a liquid concentration profile to the same position at the end of step 4 as was evident at the beginning of step 1. The termination of step 4 ends a complete cycle and initiates the beginning of a new cycle with the start of step 1. When starting with a condition where the sorbent medium in sorbent bed 14 is totally surrounded by water a steady state is reached in about 15 hours following a series of cycled steps 1 through 4. It is possible to arrive in under 6 hours at steady state conditions with certain other manual manipulations. Results At steady state operation the sugar purity of the collected extract 30 is about 95% and has a total solids content of about 38% The sugar purity for raffinate 32 is about 11% and has a total solids concentration of about 4%. About 96.5% of the sugar introduced is found in extract 30 which also contains about 15% of the impurities. About 85% of the impurities are found in raffinate 32 which also contains about 3.5% of the sugar introduced. EXAMPLE 2 Pseudo-moving, Single Bed Separator With Stationary Positions of Inlet and Outlet Points, Simultaneous Introduction of Feedstock and Eluent and Withdrawal of Fractionated Eluents in the Shortest Possible Time. (FIG. 3) FIG. 3 diagrammatically illustrates another version of a single pseudo moving sorbent bed separator according t this invention. This version is also based on the imaginary division of a single sorbent bed into four basic Zones A, B, C and D and a concentration profile similar to that shown in FIG. 2. The size of sorbent bed 54 and other operating conditions are the same as for Example 1. Step 1: Injection of Blend and Eluent and Withdrawal of Fractionated Eluents During Continued Circulation Step 1 is initiated with the circulation liquid exhibiting a concentration profile similar to that illustrated in FIG. 1 with the lowest total dissolved solids concentration in Zone A at distributor 60, optimum extract concentration in Zone B at collector 61, feedstock purity in Zone C at distributor 62 and optimum raffinate concentration in Zone D at collector 63. Valves 67, 75, 71 and 81 are opened about the same time to (1) inject eluent 66 into Zone A at a rate of 19.9 liters per minute for 3 minutes through top valve 67 and thereafter for an additional 2 minutes at a rate of 17.8 liters per minute, (2) withdraw extract 74 for 3 minutes from Zone B through collector 61 and valve 75 at a rate of 7.4 liters per minute, (3) inject feedstock 70 for 3 minutes into Zone C through valve 11 and distributor 62 at a rate of 5.3 liters per minute, and (4) withdraw raffinate 80 for 5 minutes at a rate of about 17.8 liters per minute from Zone D through collector 63 and valve 81 to maintain suction pressure for pump 85 at the predetermined level. Pump 85 is manipulated during the first three minutes of step 1 to maintain a circulation flowrate of 5.0 liters per minute as measured at flowmeter 88. Valves 75 and 71 close after 3 minutes into step 1, while valves 67 and 81 remain open for 5 minutes while the circulation flow increases to 7.5 liters per minute during the final 2 minutes of step 1. Step 2: Recycle Valves 67 and 81 are closed at the end of step 1 and circulation pump 85 is manipulated to maintain a circulation flowrate of 18.0 liters per minute across flowmeter 88 for a period 25 minutes or until the concentration profile which prevailed at the beginning of step 1 is re-established throughout the sorbent bed. Results Overall operating results will be similar to those shown for example 1. EXAMPLE 3 Pseudo Moving, Single Bed Separator with Simultaneous Injections of Feed Syrup and Eluent and Withdrawals of Separated Fractions using Dynamically Shifting Functions for Respective Distributors and Collectors (FIG. 4) Example 3 is based on the operation with the design according to this invention illustrated in FIG. 4 and using the basic operating conditions as for Example 1. Step 1: Injecting Blend and Eluent While Withdrawing Separated Fractions During Continued Circulation With the system at steady state and an optimum concentration profile similar to that illustrated in FIG. 2 established, the beginning of step 1 has been arbitrarily assigned when the circulation liquid surrounding the circulation distributor 106 in Zone A is nearly void of any dissolved substance. At that point the circulation liquid at collector 110 in Zone B is approximately at the highest sugar purity while approximately purity equivalency between the feed syrup in the feedstock 130 and the circulation liquid 120 is reached at distributor 112 in Zone C and the desired composition in raffinate 160 is measured at collector 114 in Zone D. At that point, top valve 141 is opened to inject water at a rate of 15.9 liters per minute, valve 151 at distributor 110 is opened to withdraw 3.8 liters per minute extract 150, valve 131 at distributor 112 is opened to inject 2.65 liters per minute feedstock 130 and valve 161 at distributor 114 is opened to withdraw approximately 14.75 liters per minute raffinate to maintain the hydraulic balance in the loop by controlling the suction pressure at pump 122 in the target range. Pump 122 is manipulated during step 1 to maintain the flow across circulation flowmeter 126 at 6 liters per minute. The duration of step 1 is 1.5 minutes. Step 2: Recycle All inlet and outlet valves are closed at the beginning of step 2 while pump 122 is manipulated to maintain for 6 minutes a circulation flowrate across flowmeter 126 of 18.5 liters per minute or until the optimum raffinate concentration in Zone D surrounds collector 116. Step 3: Injecting Blend and Eluent While Withdrawing Separated Fractions During Continued Circulation Step 3 repeats the flow and time conditions for step 1 with the opening of valve 142 to inject water through distributor 111 at a rate of 15.9 liters per minute, valve 152 is opened to withdraw extract 150 through collector 112 at a rate of 3.8 liters per minute, valve 132 is opened to inject feedstock 130 at a rate of 2.65 liter per minute through distributor 115 and valve 162 is opened to withdraw raffinate through collector 116 at a flowrate of about 14.75 liters per minute to maintain the suction pressure for pump 122 in the preselected range while maintaining a basic circulation flowrate of 6 liters per minute. Step 3 is maintained for 1.5 minutes. Step 4: Recycle With all inlet and outlet valves closed step 4 repeats the conditions for step 2 until the sorbent bed profile has moved one position downstream or more precisely until the optimum raffinate concentration in sorbent bed 104 circulation liquid in Zone D surrounds collector 110, the circulation liquid in Zone A is nearly free of dissolved solids and surrounds distributor 112, the highest sugar purity is found in the Zone B of the circulation liquid surrounding collector 114 and nearly equivalent feedstock sugar purity is found in Zone C at collector 116. Step 5: Injecting Blend and Eluent While Withdrawing Separated Fractions During Continued Circulation The circulation flowrate as measured at flowmeter 126 changes to 20.75 liters per minute during step 5. All other flowrates as well as the step time remain as for step 1 after the concentration profile has moved two positions downstream with Zone D now located at collector 110 and raffinate 160 withdrawn therefrom through valve 163, Zone A around distributor 113 with eluent 140 now entering through valve 144, Zone B surrounding collector 114 and extract 150 withdrawn through collector 114 and valve 153 with Zone C surrounding collector 116 and feedsyrup 130 injected through valve 134 while all other valves are closed. Step 6: Recycle Step 6 repeats the flow and time requirements for step 2 to move the sorbent bed profile now three positions downstream from the starting position of step 1 or until the optimum raffinate concentration in Zone D surrounds collector 112, Zone A surrounds distributor 115, Zone B surrounds collector 116 and Zone C with sugar purity in the circulation liquid nearly equivalent to the feedstock now located at distributor 111. Step 7: Injecting Blend and Eluent While Withdrawing Separated Fractions During Continued Circulation With the circulation profile shifted one position downstream during steps 5 and 6 to position the raffinate Zone D around collector 112, Zone A around distributor 115, Zone B to collector 116 and Zone C to distributor 110 the respective valves 164, 143, 155 and 133 open for 1.5 minutes to deliver the respective flowrates specified for step 1 while maintaining pump 122 suction pressure in the assigned target range. The circulation flowrate measured at flowmeter 126 is controlled at 18.1 liters per minute during step 7 only for the duration of this step which is 1.5 minutes. Step 8: Recycle Step 8 is a repeat of step 2 to return the sorbent bed circulation profile to the position it occupied at the beginning of step 1. Results At steady state the extract has a sugar purity of 97% and contains about 96.6% of the sugar introduced with the feed syrup while rejecting about 89.8% of the nonsugars to the raffinate. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. 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.

An apparatus and process for concentrating a selected component from a multi-component liquid using a sorbent bed having a preferential sorption rate for the selected component. The sorbent bed is enclosed in a single vessel and is operated in a simulated moving bed technique whereby the flow profile of the liquid is continually moved downwardly through the sorbent bed. Recirculation is continuous but variable and is accompanied by the injection of eluent and feedstock and the removal of extract and raffinate at preselected times, locations, and amounts as a function of the kinetics and voidage of the sorbent bed. Extract purity and operational efficiency of the sorbent bed are the result of this novel apparatus and process.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application No. 61/531,286, filed Sep. 6, 2011, the disclosure of which is incorporated herein by reference. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] NOT APPLICABLE REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX [0003] NOT APPLICABLE BACKGROUND [0004] Commercial wireless networks have evolved through several generations today with the latest fourth generation (4G) cellular wireless network based on OFDMA and MIMO antenna technology being optimized for packet data transmission, which is expected to dominate the overall volume of wireless network traffic. In addition to the large increases in data traffic, voice can also be supported by carrying speech frames as Voice-over-IP. However, data traffic has become the main driver for increasing wireless capacity. With the explosive adoption of smart phones and similar devices there is an increasing need for more and more data capacity. [0005] Data applications are asymmetric there being much more demand for downlink capacity than for uplink capacity. This is also consistent with the flexibility in transmission equipment that can be supported by a cellular wireless network where the downlink transmission power from the Base Station (BS) to the User Equipment (UE) is much higher than the uplink transmission power from the UE to the Base Station. [0006] Existing wireless technologies (e.g., CDMA HRPD, WCDMA HSDPA, and OFDMA, i.e., LTE and WiMAX) all have limitations due to underlying transmission technology. While OFDMA may theoretically have much higher transmission capacity over the same frequency range, it can be further improved by juxtopositioning various “flavors” of Smart Antenna and MIMO technologies, but these technologies are still fundamentally limited by legacy wireless network architecture. [0007] The amount of data traffic in the current 4G and 3G networks has grown exponentially especially given the mass adoption of smart phones and other mobile devices. Yet, the RF spectrum that can be used commercially is limited and in North America the utilization of available spectrum is already near 80%. There is therefore a clear need for additional capacity per MHz of spectrum. [0008] The Active Electronic Scanned Array (AESA) technology provides a means to fundamentally update the wireless network architecture, in particular that at the cell level and it provides the potential to increase network capacity significantly. SUMMARY [0009] The present invention solves the problem of providing additional capacity by introducing a Base Station in a cellular wireless network that comprises one or more Active Electronic Scanned Arrays (AESA), each of which comprises a plurality of transmitter modules (TxM), for transmitting a RF signal to a UE, each TxM for use with at least one other corresponding TxM, each TxM being spaced apart a distance equal to a function of a Radio Frequency (RF) wavelength used by a UE and the Base Station. An AESA also comprises a plurality of receiver modules (RxMs), for receiving a RF signal from the UE, each RxM for use with at least one other corresponding RxM, each RxM being spaced apart a distance equal to a function of the RF wavelength used by the UE and the Base Station. [0010] An AESA can comprise a plurality of transmitter-receiver modules (TRM), each of which includes a physically combined transmitter, for transmitting a RF signal to a UE, and a receiver, for receiving a RF signal from the UE. The TRMs are spaced apart a distance equal to a function of the RF wavelength used by the UE and the Base Station. [0011] The UE transmits, by using its TxM/TRM, a logical control channel that contains messages of its RF channel feedback. The Base Station, on receiving and decoding such information from the UE can adjust phase alignment of a group of two or more TxMs/TRMs for subsequently transmitting RF signals to the UE. In the opposite direction, the Base Station may also transmit such a logical control channel including similar kind of control information to the UE and to allow the UE to adjust phase alignment of the modules of the UE AESA. [0012] The RF channel between the Base Station and the UE consists of two types of logical channels, i.e., the aforementioned logical control channel and the user traffic channel. The specific wireless technology, e.g., WCDMA, CDMA, WiMax, and LTE, may be designed with one or more logical control channels, and a plurality of traffic channels. [0013] A controller for the AESA, as part of the Base Station, comprises an interface to be connected with the plurality of TxMs and the plurality of RxMs. In the AESA with the TRMs, the controller is connected with the combined TRMs. In the transmission direction, the controller steers the phase alignment of the at least two TxMs (or TRMs), on one of the AESA arrays, for transmitting signals to the UE. The controller determines the direction and the compactness of the electromagnetic field carrying the RF signal through the desired phase alignment. The controller also selects the number of TxMs (or TRMs), when combined through phase alignment, to provide a more, or less, sharply focused signal, and a stronger, or a weaker, signal which leads to increased, or decreased, data transfer rate and increased, or decreased, transmission range to the UE. [0014] In the receiving direction, the controller steers the phase alignment of at least two RxMs (or TRMs) for receiving from the UE. It determines the direction of the RF signal to receive and the number of RxMs (or TRMs) for the specific UE to achieve a more, or less, sharply focused received signal, or a higher, or lower, signal gain. [0015] Through coordinating all the transmission to and receiving from all UEs, and the transmission and receiving TxMs (or TRMs) and RxMs (or TRMs), the controller maximizes the aggregate data transfer rate over the cell covered by the Base Station. [0016] The controller can be designed to operate in one or more layers. A controller may be connected to a sub-controller wherein the sub-controller is coupled with the TxMs, and the RxMs, or the combined TRMs of an AESA array. The sub-controller directly steers the TxMs and the RxMs, or TRMs. Hence, the main controller itself controls them indirectly, but can perform a more coordinating function; this allows the overall architecture to be scalable when necessary. [0017] In another aspect of the invention, a method is provided for increasing transmission and reception capacity, by utilizing an AESA array in a node in the wireless network, where the AESA is coupled to a controller for controlling independent TxMs of the AESA. The controller selects a subset of the modules dynamically based on their location, geometry, and distance to each other measured as a function of the said RF wavelength in response to the UE provided UE RF channel feedback, via a logical control channel, the RF channel feedback being used for adjusting the phase alignment of the modules and optimizing the aggregate power level to maximize the data transfer rate, where the phase alignment controls the direction of transmission of the compatible RF signals to the UE and the number of selected sets of modules controls the sharpness of the signal and the aggregate power targeted at the UE. [0018] In a further aspect of the present invention a controller is introduced. The controller controls multiple subsets of TxMs of the AESA array, where each subset is a group of TxMs selected based on their location, geometry, and distance to each other measured as a function of the said RF wavelength in response to the UE provided RF channel feedback. Each subset of TxMs transmits with compliance to a specific wireless technology standard, including GSM, WCDMA, CDMA, WiMAX, LTE, and their evolved standards to the UE capable of receiving and transmitting in the compatible technology. The selection of these TxM subsets are dynamic and based on the current RF environment characterized by the RF parameters in the system including the location of the UE and the UE's channel matrix. [0019] The single Base Station supports multiple wireless technology standards at the same time by selecting different TxM subsets and transmitting according to the said technology standard over each subset. The controller includes broadcasting and detecting means for the particular radio technology of the UE and scheduling logic operating in a processor with an associated memory that selects one of the plurality of physical or logical sub-controllers that corresponds with the radio technology of the UE. Each sub-controller comprises the logic means for selecting one or more TxMs in the shared pool of such modules of the AESA to transmit a part of or a full frequency band specific to the UE. The number, location, geometry, and distance, to each other of these modules, measured as a function of the said RF wavelength in response to the UE provided UE RF channel feedback, via a logical control channel, are controlled to optimize the desired direction of transmission to the UE and the aggregate power targeted at the UE to maximize the data transfer rate. [0020] In further aspect of the invention, a method is provided for increasing transmission and reception capacity, by utilizing an AESA array in a node in the wireless network, where the AESA is coupled to a controller for controlling independent TRMs of the AESA. The controller selects a subset of the modules dynamically in response to the UE provided UE RF channel feedback, via a logical control channel, RF channel feedback being used for adjusting the phase alignment of the modules and optimize the aggregate power level to maximize the data transfer rate, where the phase alignment controls the direction of transmission of compatible RF signals to the UE and the number of selected set of modules controls the sharpness of the signal and the aggregate power targeted at the UE. [0021] In a further aspect of the present invention a controller is introduced. The controller controls multiple subsets of TRMs of the AESA array, where each subset is a group of TRMs selected based on their location, geometry, and distance to each other measured as a function of the said RF wavelength in response to the UE provided RF channel feedback. Each subset of TRMs transmits according to a specific wireless technology standard, including GSM, WCDMA, CDMA, WiMAX, LTE, and their evolved standards to the UE capable of receiving and transmitting in the compatible technology. The selection of these TRM subsets are dynamic and based on the current RF environment characterized by the RF parameters in the system including the UE RF channel feedback. The single Base Station supports multiple wireless technology standards at the same time by selecting different TRM subsets and transmitting the said technology standard over each subset. The controller includes broadcasting and detecting means for the particular radio technology of the UE and scheduling logic operating in a processor with an associated memory that selects one of the plurality of physical or logical sub-controllers that corresponds with the radio technology of the UE. Each sub-controller comprises the logic means for selecting one or more transmission modules in the shared pool of such modules of the AESA to transmit a part of or a full frequency band specific to the UE. The number, location, geometry, and distance, to each other of these modules, measured as a function of the said RF wavelength in response to the UE provided UE RF channel feedback, via a logical control channel, are controlled to optimize the desired direction of transmission to the UE and the aggregate power targeted at the UE to maximize the data transfer rate. [0022] In a further aspect of the present invention a system providing increased transmission capacity in a wireless network comprises a user equipment (UE) in communication with a Base Station capable of at least one of GSM, WCDMA, CDMA, WiMAX, LTE, and their evolved technology standards. The BS comprises an (AESA) array, for transmitting and receiving RF radio frequency signals to and from the UE in the compatible technology standards. The UE contains TxMs and RxMs and transmits at least one logical control channel to provide its RF channel feedback, for example, its location and geographical information to the BS and a channel matrix that includes information of its estimate of the condition of the RF channels in the direction from the BS to the UE. [0023] In another aspect of the present invention a system providing increased transmission capacity in a wireless network comprises a user equipment (UE) in communication with a Base Station capable of at least one of GSM, WCDMA, CDMA, WiMAX, LTE, and their evolved technology standards. The BS comprises an (AESA) array, for transmitting and receiving RF radio frequency signals to and from the UE in the compatible technology standards. The UE contains TRMs and transmits at least one logical control channel to provide its RF channel feedback, for example, its location and geographical information to the BS and a channel matrix that includes information of its estimate of the condition of the RF channels in the direction from the BS to the UE. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0024] The novel features believed characteristic of the invention are set forth in the appended claims. The invention will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: [0025] FIG. 1 is a military AESA radar installation in an F-22 Raptor Fighter; [0026] FIG. 2 , depicts a block diagram of an AESA radar antenna, wherein each “pin” is an AESA transmitter/receiver module; [0027] FIG. 3 , illustrates a high level block diagram of each TxM being connected to a phase shift module (PSM) that provides a controllable phase shift of the RF signal; [0028] FIG. 4 a depicts two-sine waves that when perfectly aligned in phase multiply the signal; [0029] FIG. 4 b illustrates the effect when two sine waves are perfectly out-of phase signals; [0030] FIG. 5 depicts the additive effect of multiple Transmitter modules transmitting in phase; [0031] FIG. 6 illustrates channel update as transmitted from the UE at regular intervals; [0032] FIG. 7 a depicts a high level block diagram of a network in accordance with the present invention; [0033] FIG. 7 b illustrates a User Equipment; [0034] FIG. 7 c depicts a high level block diagram of a Base Station; [0035] FIG. 8 a depicts a high level block diagram of a Base Station incorporating an AESA antenna configuration in accordance with a preferred embodiment of the invention; [0036] FIG. 8 b illustrates a high level block diagram of the Active Electronic Scanned Array (AESA) configuration in a Base Station in accordance with a preferred embodiment of the present invention; [0037] FIG. 9 is a high level flow chart for a process of utilizing a AESA in accordance with a preferred embodiment of the present invention; and [0038] FIG. 10 depicts the Base Station transmission power in at least four different directions, each having the same spatial signature in accordance with a preferred embodiment of the present invention. DETAILED DESCRIPTION [0039] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present invention. [0040] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” or “according to one embodiment” (or other phrases having similar import) at various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Furthermore, depending on the context of discussion herein, a singular term may include its plural forms and a plural term may include its singular form. Similarly, a hyphenated term (e.g., “on-demand”) may be occasionally interchangeably used with its non-hyphenated version (e.g., “on demand”), a capitalized entry (e.g., “Software”) may be interchangeably used with its non-capitalized version (e.g., “software”), a plural term may be indicated with or without an apostrophe (e.g., PE's or PEs), and an italicized term (e.g., “N+1”) may be interchangeably used with its non-italicized version (e.g., “N+1”). Such occasional interchangeable uses shall not be considered inconsistent with each other. [0041] It is noted at the outset that the terms “coupled,” “connected”, “connecting,” “electrically connected,” etc., are used interchangeably herein to generally refer to the condition of being electrically/electronically connected. Similarly, a first entity is considered to be in “communication” with a second entity (or entities) when the first entity electrically sends and/or receives (whether through wireline or wireless means) information signals (whether containing data information or non-data/control information) to the second entity regardless of the type (analog or digital) of those signals. It is further noted that various figures (including component diagrams) shown and discussed herein are for illustrative purpose only, and are not drawn to scale. [0042] The functionality can be implemented by means of hardware comprising several distinct elements and by means of a suitably programmed processing apparatus. The processing apparatus can comprise a computer, a microprocessor, a state machine, a logic array or any other suitable processing apparatus. The processing apparatus can be a general-purpose processor which executes software to cause the general-purpose processor to perform the required tasks, or the processing apparatus can be dedicated to perform the required functions. Another aspect of the invention provides machine-readable instructions (software) which, when executed by a processor, perform any of the described methods. The machine-readable instructions may be stored on an electronic memory device, hard disk, optical disk or other machine-readable storage medium. The machine-readable instructions can be downloaded to a processing apparatus via a network connection. [0043] Abbreviations [0044] 3GPP 3rd Generation Project Partnership [0045] 3GPP2 3rd Generation Project Partnership 2 [0046] AESA Active Electronic Scanned Array [0047] BTS Base Transceiver Station [0048] CDMA Code Division Multiple Access [0049] CQI Channel Quality Indicator [0050] CSI Channel State Indication [0051] DL Downlink [0052] DRC Data Rate Control [0053] FDMA Frequency Division Multiple Access [0054] GPS Global Positioning System [0055] HRPD High Rate Packet Data [0056] HSDPA High Speed Downlink Packet-Data Access [0057] LTE Long Term Evolution (3GPP) [0058] MIMO Multiple-In Multiple-Out [0059] OFDMA Orthogonal Frequency Division Multiple Access [0060] PN Pseudo-sequence Number [0061] PSM Phase Shift Module [0062] RF Radio Frequency [0063] Rx Receive [0064] RxM Receiver Module [0065] SC-FDMA Single Carrier-Frequency Division Multiple Access [0066] TDMA Time Division Multiple Access [0067] TRM Transmitter/Receiver Module [0068] Tx Transmit [0069] TxM Transmitter Module [0070] UE User Equipment [0071] UL Uplink [0072] UMTS University Mobile Telecommunications System [0073] WIMAX Worldwide Interoperability for Microwave Access [0074] WCDMA Wide-Band CDMA [0075] Active Electronic Scanned Array (AESA), is a key wireless technology in modern radar and typically requires a massive amount of compute-power to control and manage AESA transmission and reception. It is expected by the time of 4G wireless networks and beyond, the required computing power and the related AESA cost issues will be resolved due to continued progress in electronics and semiconductor technologies. Adapting the AESA technology to a mobile or fixed wireless network can provide many times of capacity increase in the downlink and uplink. AESA technology, when applied to wireless transmission equipment can improve capacity by utilizing thousands of transmitter modules in the Base Station and can devote as many transmitter modules to each user as needed and as permitted within the coverage of a cell. The cost of such equipment is currently high but, it is already trending down and with mass commercialization, the equipment would become affordable. [0076] AESA transmission and reception can be designed to be directional towards individual User Equipment (UE). By increasing the number of transmitter modules that work together, the network can support users further and further away from the cell center as long as the uplink transmit technology from the user permits. And equally, it can scale up the amount of data transmitted to the user (or a group of users), depending on the RF environment of each user, by steering more transmitter modules towards the user in one or more specific directions. The capacity that can be exploited is potentially large as the transmission power can be scaled with more transmission modules and time-sharing the transmission of data to many users in many directions. [0077] FIG. 1 is a photograph of a military AESA radar installation in an F-22 Raptor Fighter. The application of AESA technology, to date, has not been used in the commercial wireless communications field. However, with progress made in solid state electronic components, AESA transmitters have become much smaller and, with mass commercialization, trending to becoming more affordable. [0078] FIG. 2 , illustrates a block diagram of an AESA radar antenna, wherein each of the multitude of pins as shown in FIG. 1 are represented by the small circles, each of the circles representing an AESA transmitter/receiver module (TxM/RxM). Note the “pins” should fill the AESA transmitter panel or panels, though not all are depicted in the figure. In an advanced fighter plane such as the F35, part of the AESA array can be directed for point-to-point high capacity data link communications. Each TxM consumes very little power, a few hundred milli-watts up to a few watts. [0079] FIG. 3 depicts each TxM connected to a phase shift module (PSM) that provides a controllable phase shift of the RF signal. (The PSM can be a separate device or contained within the TxM.) A subset of the TxMs can be targeted in a specific direction towards a User Equipment (UE) where the Tx signal from each TxM overlaps in space and interferes constructively to reinforce the signal in this specific direction; this is done by controlling the PSM phase shift of the transmitted signal from each TxM. In a simple case, a TxM may transmit a narrow-band simple sine-wave form signal. Constructive interference between signals from different modules, when phase controlled, reinforces the signal in the desired direction. The Tx modules are controlled as a subset to a user and in time, where a control channel with the AESA array or any traditional 3G/4G technology is used for timing alignment, network signaling, and resource scheduling. [0080] The target of the transmitted signal is a mobile or fixed wireless device generically referred to as a User Equipment (UE). The AESA Tx modules (TxM) are part of the Base Station transceiver system (BS), which utilizes the TxMs to schedule and transmit data to the UE. [0081] Each of the TxMs is controlled so as to be phase aligned such that signals from the subset of TxMs interfere constructively (signals are additive) in the direction of a User Equipment and within a computed distance of the UE from the Base Station cell center. The UE transmits its RF channel feedback in the UL, including Channel State Information (CSI), including that for the DL channel to the UE and that for the UL channel from the UE, the accepted data rate from the Base Station to the UE, the transmitted data rate from the UE to the Base Station, and the position information of the UE transmitted signal, including, location, elevation, and orientation so that the TxM can be steered to transmit accurately to the UE even when it is mobile. [0082] For example, by delaying the phase shift of some TxM elements in relation to other modules in a particular group of Tx modules, the direction of the transmitted signal is steered by the angle of θ as shown in FIG. 3 . Note, there are no moving parts in the steering of the transmission direction of the desired signals as the modules are electronically steered rather than being steered mechanically, which reduces the need for maintenance. [0083] Each cell or sector within the wireless network has one or more AESA panels coupled with one or more Base Stations (see FIG. 2 ). The more TxM and RxM modules in the array the higher the potential transmission capacity, being limited only by the electric power supply, the space to accommodate the AESA, and the range of the transmission frequency band. [0084] As illustrated in FIG. 4 a , two-sine waves multiply when perfectly aligned in phase. The signal strength almost doubles, hence even though an individual TxM power may be low, the cascaded transmit power of a group of aligned TxMs becomes large and can target a UE from a significant distance (however the signal will still attenuate in free space exponentially). The opposite is true when two sine-waves are out of phase as in FIG. 4( b ), where perfectly out-of phase signals sum to zero. [0085] The phase shift is done in such a manner as to delay some of the TxM signals within the same subgroup where the signal phase aligns in a specific direction, resulting in constructive interference. In other directions, the signals interfere destructively and hence the signal is degraded. Because each TxM module transmits a small amount of power, the direction of constructive interference cascades and produces a stronger signal. The direction of non-constructive interference transmits no more than a few hundred meters before signals dissipate through attenuation in free space. [0086] FIG. 5 illustrates the additive effect of multiple TxM transmitting in phase, where the signal is strengthened (i.e., appearing brighter) in the direction of the phase alignment. [0087] The number of TxM modules required can be determined from a desired signal strength, which determines a modulation and coding scheme (hence the achievable data rate) and the expected attenuation of the signal in the transmission environment given the distance to the target receiver and the RF channel. Note there are other factors that limit the number of TxMs being added, for example, the Uplink (UL) transmission from the UE and the desired cell sizes. The estimate of the number of modules required can be computed from channel feedback from the UE in the UL The more TxMs are allocated to a target, the stronger the multiplied signal strength is, hence the higher modulation and coding scheme, or the further away the receiver may be located. [0088] The Tx direction can be determined from periodic channel feedback by the UE in the UL direction. As illustrated in FIG. 6 , channel feedback update is transmitted from the UE at regular intervals to ensure that the BS has up to date information to determine the direction of the transmission to the UE. [0089] In the simplest form, the TxM transmits a narrow band sine-wave signal that time-multiplexes a reference pilot signal with a predetermined modulation and coding scheme and bit sequence and payload data to the target UE. For GSM, CDMA, WCDMA, OFDMA (e.g., LTE and WiMAX), the respective transmitted signal waveform apply to that specific technology. [0090] Each TxM module is an independent transmitter in the sense that it can be controlled to transmit a specific frequency at a time, and the directionality of the DL transmission is such that there is a high level of frequency reuse within the same network cell. Each TxM is capable of transmitting at a wide range of frequencies so that a Pseudo-random Number (PN) sequence may be used to control the transmission to use frequency-hopping for diversity gain and interference robustness of the design. [0091] In the UL, the direction of transmission and channel feedback are reversed. In particular, the channel feedback includes Channel State Information (CSI), including that for the UL channel to the Base Station and that for the DL channel from the Base Station, the accepted data rate from the UE to the Base Station, the transmitted data rate from the Base Station to the UE, and the position information of the Base Station transmitted signal, including, location, elevation, and orientation. However, the same principles apply. In the UL the UE is the transmitter and the Base Station is the receiver. The Base Station Rx modules are steered in phase to align to a direction of the transmitted signal from the UE. This has the benefit of optimizing the desired signal in specific signal paths and direction, and minimizing any interference from other directions. A subset of RxMs can be controlled according to specific separation, as a function of the frequency wavelength, for a particular UE to maximize receive diversity or to maximize data rate. [0092] The DL and UL transmitted signal may employ any existing wireless technologies, including CDMA, CDMA EVDO, WCDMA, and OFDMA (e.g., LTE and WiMAX) as defined by 3GPP and 3GPP2. A specific channel in the UL (or DL) direction is employed for signaling the channel feedback, and it may also be used for scheduling of resources for the DL (or UL) direction using any of these existing wireless technologies. The Base Station (or the UE) transmission direction can be adjusted in response to the channel feedback from the UE (or the Base Station), typically within milliseconds, to ensure adaptation to RF conditions and to keep up with UE mobility. [0093] FIG. 7 a depicts a high level block diagram of a network in accordance with the present invention. The network can include one or more instances of user equipment (UEs) and one or more Base Stations capable of communicating with these UEs, along with any additional elements suitable to support communication between UEs or between a UE and another communication device (such as a landline telephone). Although the illustrated UEs may represent communication devices that include any suitable combination of hardware and software, these UEs may, in particular embodiments represent devices such as the example UE illustrated in greater detail by FIG. 7 b . Similarly, although the illustrated Base Stations represent network nodes that include any suitable combination of hardware and software, these Base Stations may, in particular embodiments, represent devices such as the example Base Station illustrated in greater detail by FIG. 7 c. [0094] FIG. 7 b illustrates an example UE which includes a microprocessor, a memory, a transceiver, and an antenna. In particular embodiments, some or all of the functionality described above as being provided by mobile communication devices or other forms of UE may be provided by the UE processor executing instructions stored on a computer-readable medium, such as the memory shown in FIG. 7 b . Alternative embodiments of the UE may include additional components beyond those shown in FIG. 8 that may be responsible for providing certain aspects of the UE's functionality, including any of the functionality described above and/or any functionality necessary to support the solution described above. [0095] As depicted in FIG. 7 b , the example Base Station includes a microprocessor, a memory, a transceiver, and an antenna. In particular embodiments, some or all of the functionality described above as being provided by a mobile Base Station, a Base Station Controller, a Node B, an enhanced Node B, or any other type of mobile communications node executing instructions stored in the memory. Alternative embodiments of the Base Station may include additional components responsible for providing additional functionality, including any of the functionality identified above and/or any functionality necessary to support the solution described above. [0096] FIG. 8 a depicts a high level block diagram of a Base Station incorporating an AESA antenna configuration in accordance with a preferred embodiment of the invention. Base Station 802 includes controller 804 , which manages sub-controller 806 which, in turn, controls the transmitter and receiver modules of AESA 808 . The sub-controller may control and operate the TxMs and RxMs individually, in pairs or in groups of modules. Not pictured are UEs and the rest of the network of which Base Station 802 is an integral part. Even though there is only one sub-controller 806 shown for ease of explanation, there can be multiple sub-controllers that are controlled by controller 804 . As will be shown in FIG. 8 b , sub-controllers representing various and different radio access technologies can be simultaneously controlled both for transmitting and receiving. The AESA Base Station may be considered a “universal” Base Station as virtually any radio access technology may be handled at the same time both receiving and transmitting. This feature of the invention could give rise to an independent, single Base Station operator entity that can serve multiple telecom operators at the same time. [0097] FIG. 8 b illustrates a high level block diagram of the AESA antenna configuration in a Base Station in accordance with a preferred embodiment of the present invention. High capacity AESA 808 is managed by controller 804 , which includes a number of sub-controllers for controlling various wireless technologies, three of which are illustrated here. Because of room and clarity of explanation only three technologies are represented here and include GSM-sc (GSM subcontroller) 806 a, WCDMA-sc 806 b and LTE-sc 806 c. The number of sub-controllers is limited only by available space and power requirements of AESA 808 . Various TxM/RxM pairs can be taken over and controlled by the individual subcontrollers on an as needed and as available basis. In other words, if a pair of TxM/RxM (previously used by GSM-sc) is now idle and a need arises for LTE transmission and reception, LTE-sc 806 c may be utilized by controller 804 to connect, e.g., Tx group 812 to an LTE enabled wireless communications device. [0098] AESA 808 consists of a large number of low-powered, independent transmitter modules (TxM) 810 and a similarly large number (but not necessarily the same number) of independent receiver modules (RxM). Sub-controllers can take over various groups of transmitters and/or receivers (e.g., 812 , 814 , 816 and 818 ) in response to a UE's requirement for signal power. Because each TxM and RxM is independently controlled and can be spatially separated flexibly, a subset or subsets of TxM (or RxM) can be steered through phase-shift electronically using phase shift module (not shown) for beam-forming, Tx/Rx diversity, or spatial multiplexing to each UE within the coverage area of AESA 808 . A controlling algorithm has the flexibility to choose from a large number of active Tx/Rx module pairs or groups as well as applying different transmission methods to these subsets of modules. [0099] The TxM and RxM are active and are independently (in frequency, phase, and power) steered utilizing the aforementioned phase shift module. The pairs or groups of TxM and RxM are utilized on an as-needed basis in subsets to the overall set of modules to support multiple UEs, each UE possibly using a different radio access technology, that are accessing the network. Since the modules are strategically separated spatially, flexibility is afforded by the reach (i.e., power level when interfering constructively) and Tx/Rx direction (i.e., phase shift). [0100] The TxM and RxM modules may be physically combined as a TRM, thus each module in FIG. 8 a and FIG. 8 b is capable of transmitting in the DL, and receiving in the UL. Similar to the TxM and RxM each TRM module can be individually steered by the controller, but the transmit and receive direction will be the same. [0101] FIG. 9 is a high level flow chart for a process of utilizing a AESA in accordance with a preferred embodiment of the present invention. The steps in this process are for an AESA having separate TxM and RxM modules. In a process involving TRMs (combination of TxM and RxM), the steps are similar and will not be recited here. The process involving TxM and RxM modules begins at step 902 with the reception of a signal (including control channels, traffic channels, channel feedback, and pilot signal) from a User Equipment (UE) at a Base Station in which an AESA is incorporated. The process then moves to step 904 where a controller for the AESA determines the wireless technology of the UE signal. Typically the UE registers with the system as it enters the system, including one or more of wireless technologies that it supports. [0102] Next, the process proceeds to step 906 with the controller directing the signal to a sub-controller that handles the wireless technology of the UE. The wireless technologies that are handled by the Base Station in which AESA is installed may include CDMA, GSM, WCDMA and LTE. The ability to handle the different technologies is found in selecting available transmitter modules that are spaced a distance apart as a function of the wavelength of the operating frequency of the UE. Any of the modules, receiver or transmitter, can be used to carry signals to and from almost any UE because of the ability to select the spacing of the transmitting and receiving modules. [0103] The sub-controller allocates frequencies and time slots for the transmission to and reception from the UE. It also determines the direction of the transmission and reception using data received from the UE RF channel feedback. More TxM modules are used for higher signal strength, and for a more sharply focused signal, specifically spaced TxM modules and the individual phase shifts are used for the transmission direction. Similarly, more RxM modules for higher gain, and specifically spaced RxM modules and the phase shifts for the direction. After the TxMs are chosen, the process moves to step 910 , where phase alignment is applied to the group of TxMs for transmission and RxMs for receiving. In the next step, step 914 , as the UE changes direction and distance from the Base Station, the Base Station continues to monitor the UE, and the process restarts from 902 again, where the number of TxMs and RxMs, phase alignment of each module, overall power, and overall gain, in UL and DL, are constantly adjusted by the sub-controller so as to maintain or increase data transfer. [0104] In step 916 , as the UE using GSM wireless technology leaves the cell covered by the Base Station, another UE using LTE may enter the same cell. As the Tx modules are now idle, the LTE controller can utilize the vacant Tx and Rx modules for the LTE controller. If the GSM UE is in the cell when the LTE UE is acquired by the AESA Base Station, the LTE sub-controller selects idle RxM and TxM modules to connect to the LTE UE. As multiple UEs enter the cell, depending on the availability of Tx and Rx modules, all of the UEs regardless of wireless technology, can be served by the AESA Base Station. [0105] FIG. 10 shows that the Tx power to the UEs in the same spatial signature group can be precisely controlled to multiplex many UEs in the same direction, which allows data rate maximization overall in the coverage area of the cell, and the power of different frequencies being limits to achieve a balanced data rate to the target UEs, while at the same time to reduce the interference to adjacent cells. Using LTE as an example, which uses OFDMA signals and have some very attractive properties, each TxM (or RxM) module group can be modulated with OFDM symbols to multiplex more users with the same spatial signatures as captured by channel feedback. The multiplexed OFDM signals may compose of many frequencies, have the same direction, and may have different power for each subset of frequencies. [0106] In each direction, a specific AESA channel can be formed with reduced interference between channels. The lope of the channel can be controlled to be narrower or wider depending on the covered area and UEs as needed by controlling more or fewer TxM and RxM modules and their spacing on the AESA arrays. The important aspect of this Base Station architecture using the AESA is that each channel can be dynamically constructed depending on the need as obtained from the channel feedback from the UE. In fact, the different channels are omni-directional and spans different directions across 360 degrees and from the ground to the required elevation at different times and for different UEs. [0107] Each channel can be transmitting one of the supported wireless technologies, i.e., GSM, CDMA, WCDMA, LTE, WiMAX, and their derivatives. [0108] Although the described solutions may be implemented in any appropriate type of telecommunication system supporting any suitable communication standards and using any suitable components, particular embodiments of the described solutions may be implemented in a network, such as that illustrated in FIG. 7 . [0109] As will be recognized by those skilled in the art, the innovative concepts described in the present application can be modified and varied over a wide range of applications. Accordingly, the scope of patented subject matter should not be limited to any of the specific exemplary teachings discussed above, but is instead defined by the following claims

A base station in a network includes an Active Electronic Scanned Array (AESA) to enhance and increase transmission and reception in a wireless telecommunications network. The AESA comprises a plurality of transmitter and receiver modules for sending and receiving signals from a User Equipment (UE) with increased signal strength and higher gain. The AESA comprises a central controller; and subcontrollers that cause signals to be directed to specific transmission modules (TxMs) and receiver modules (RxMs) in the AESA to send to the UE. By increasing the number of TxMs used, the signal strength to the UE can be increased significantly. Subcontrollers for handling different radio frequencies can be utilized in the same AESA so that multiple telecommunication systems can be accommodated on a single base station.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisional of U.S. patent application Ser. No. 11/408,474 filed on Apr. 21, 2006, which is incorporated by reference herein in its entirety. FIELD The present invention relates to covered stents for use in various medical procedures. BACKGROUND The following terms used herein are defined as follows: The term “stent” means a frame structure containing openings through its wall, typically cylindrical in shape, intended for implantation into the body. A stent may be self-expanding and/or expanded using applied forces. As used herein, the terms “covered stent” and “stent-graft” are used interchangeably to mean a stent with a cover on at least a portion of its length. The cover can be on the outer surface, the inner surface, on both surfaces of the stent, or the stent may be embedded within the cover itself. The cover may be porous or non-porous and permeable or non-permeable. Active or inactive agents or fillers can be attached to or incorporated into the cover. Referring to FIG. 4 a , as used in this application, the term “wrinkle” 65 a , 65 b means a fold in a stent cover 62 that has a larger peak to valley height 64 than a thickness 66 of an adjacent stent strut 68 . In the illustrated instance where the cover is mounted within the stent, a wrinkle 65 a in a cover 62 on the outer surface of a covered stent 60 may be identified where the cover extends beyond the inner surface of the stent struts 68 . A wrinkle 65 b can also extend radially inward. Referring to FIG. 4 b , a wrinkle 65 a in a cover on the inner surface of a covered stent 60 can extend radially outward. Such an outward-extending wrinkle may be identified where the cover 62 extends beyond the outer surface of the stent struts 68 as shown in FIG. 4 b . A wrinkle 65 b can also extend radially inward as shown in FIG. 4 b Wrinkles can be observed with unaided vision or they can be observed and measured under magnification, such as optical microscopy. “Wrinkle-free” means a stent covering that is substantially free of “wrinkles.” As used herein, the term “expand” has two distinct meanings. When used in the context of describing stents, it refers to the increase in diameter of those devices. When used in the context of ePTFE material, it refers to the stretching (i.e., expansion) process used to render PTFE material stronger and porous. As used herein, the term “self-expanding” means the attribute of a device that describes that it expands outwardly, such as in a general radial direction, upon removal of a constraining means, thereby increasing in diameter without the aid of an external force. That is, self-expanding devices inherently increase in diameter once a constraining mechanism is removed. Constraining means include, but are not limited to, tubes from which the stent or covered stent device is removed, such as by pushing. Alternatively, a constraining tube or sheath may be disrupted to free the device or the constraining means can be unraveled should it be constructed of a fiber or fibers. External forces, as provided by balloon catheters for example, may be used prior to expansion to help initiate an expansion process, during expansion to facilitate expansion, and/or after stent or covered stent deployment to further expand or otherwise help fully deploy and seat the device. As used herein, the term “fully deployed” refers to the state of a self-expanding stent after which the constraining means has been removed and the stent, at about 37° C. over the course of 30 seconds, has expanded under its own means without any restriction. A portion or portions of a self-expanding stent may be fully deployed and the remainder of the stent may be not fully deployed. The phrase, “operating diametric range” refers to the diametric size range over which the stent or stent-graft will be used and typically refers to the inner diameter of the device. Devices are frequently implanted in vessel diameters smaller than that corresponding to the device fully deployed state. This operating range may be the labeled size(s) that appear in the product literature or on the product package or it can encompass a wider range, depending on the use of the device. As used herein, the term “porous” describes a material that contains small or microscopic openings, or pores. Without limitation, “porous” is inclusive of materials that possess pores that are observable under microscopic examination. “Non-porous” refers to materials that are substantially free of pores. The term “permeable” describes a material through which fluids (liquid and/or gas) can pass. “Impermeable” describes materials that block the passage of fluids. It should be appreciated that a material may be non-porous yet still be permeable to certain substances. Stents and covered stents have a long history in the treatment of trauma-related injuries and disease, especially in the treatment of vascular disease. Stents can provide a dimensionally stable conduit for blood flow. Stents prevent vessel recoil subsequent to balloon dilatation thereby maintaining maximal blood flow. Covered stents can provide the additional benefits of preventing blood leakage through the wall of the device and inhibiting, if not preventing, tissue growth through the stent into the lumen of the device. Such growth through the interstices of the stent may obviate the intended benefits of the stenting procedure. In the treatment of carotid arteries and the neurovasculature, coverings trap plaque particles and other potential emboli against the vessel wall thereby preventing them from entering the blood stream and possibly causing a stroke. Coverings on stents are also highly desirable for the treatment of aneurismal vascular disease. The covers may further act as useful substrates for adding fillers or other bioactive agents (such as anticoagulant drugs, antibiotics, growth inhibiting agents, and the like) to enhance device performance. The stent covers may extend along a portion or portions or along the entire length of the stent. Generally, stent covers should be biocompatible and robust. They can be subjected to cyclic stresses about a non-zero mean pressure. Consequently, it is desirable for them to be fatigue and creep resistant in order to resist the long-term effects of blood pressure. It is also desirable that stent covers be wear-resistant and abrasion-resistant. These attributes are balanced with a desire to provide as thin a cover as possible in order to achieve as small a delivery profile as possible. Covers compromise the flow cross-section of the devices, thereby narrowing the blood flow area of the device, which increases the resistance to flow. While increased flow area is desirable, durability can be critical to the long-term performance of covered stents. Design choice, therefore, may favor the stronger, hence thicker, covering. Thick covers, however, are more resistant to distension than otherwise identical thinner covers. Some balloon-expandable stent covers are wrinkle-free over the operating range of the stents because the extreme pressures of the balloons can distend the thick, strong covers that are placed onto the stent at a less than a fully deployed stent diameter. Even the thinnest covers in the prior art such as those made of ePTFE (e.g., those taught in U.S. Pat. No. 6,923,827 to Campbell et al., and U.S. Pat. No. 5,800,522 to Campbell et al.), however, may be too unyielding to be distended by the radial forces exerted by even the most robust self-expanding stents. Non-elastic and non-deformable self-expanding stent covers are, therefore, generally attached in a wrinkle-free state to the stent when the stent is fully deployed. When such covered stents are at any outer diameter smaller than the fully deployed outer diameter, the cover is necessarily wrinkled. These wrinkles, unfortunately, can serve as sites for flow disruption, clot initiation, infection, and other problems. The presence of wrinkles may be especially deleterious at the inlet to covered stents. The gap between the wrinkled leading edge of the cover and the host vessel wall can be a site for thrombus accumulation and proliferation. The adverse consequences of wrinkles are particularly significant in small diameter vessels which are prone to fail due to thrombosis, and even more significant in the small vessels that provide blood to the brain. The use of thin, strong materials is known for implantable devices (e.g., those taught in U.S. Pat. No. 5,735,892 to Myers et al.). Extremely thin films of expanded PTFE (ePTFE) have been taught to cover both self-expanding and balloon expandable stents. Typically these films are oriented during the construction of the devices to impart strength in the circumferential direction of the device. Consequently, the expanding forces of the self-expanding stents may be far too low to distend these materials. In fact, such devices are generally designed to withstand high pressures. These coverings, like those of other coverings in the art, are wrinkle-free only when the devices are fully deployed. Thin, extruded but not expanded fluoropolymer tubes have been used to cover self-expanding and balloon-expandable stents (e.g., U.S. Patent Application 2003/0082324 A1 to Sogard). These seamless extruded tube covers are applied to self-expanding stents in the fully deployed state of the stents. The stent coverings, therefore, possess wrinkles upon crushing the device to a diameter smaller than the fully deployed diameter. Expanded PTFE material has been used to cover stents that are self-expanding up to a given diameter, then use the assistance of a balloon catheter or other expansion force to achieve the desired clinical implantation diameter (e.g., U.S. Pat. No. 6,336,937 to Vonesh et al). Such covers are wrinkled in the range of diameters up to the diameter at which the stent expands on its own. Beyond that diameter, the covers may be relatively wrinkle-free, however, the stent may no longer be freely self-expanding. Another type of covered stent previously disclosed (e.g., U.S. Patent Application 2002/0178570 A1 to Sogard) is constructed with two polymeric liners laminated together yet not adhered to the stent. In the absence of bonding a liner to the stent, both an inner and outer liner are necessary and they need to be bonded together at the stent openings in order to construct a coherent stent-graft. This construction provides a relatively smooth liner on one side of the stent. The outer liner follows the geometry of the stent strut and is bonded to the inner liner. As such, according to the definition of a “wrinkle” as provided herein, the outer liner is wrinkled. Expanded PTFE liners of self-expanding covered stents made with shape memory alloys were taught to be laminated together at elevated temperatures, as high as 250° C. (and below 327° C.), while not exceeding a stent temperature which might reset the shape memory state of the alloy. In the absence of bonding the liners to the stent struts, gaps are formed between the liners. Such gaps may become filled with biological materials that compromise the blood flow area and, therefore, may restrict blood flow. Without the addition of other materials, expanded PTFE materials must be heated well above 200° C. in order the heat bond them together. Given that these stent-graft devices are intended to self-expand at body temperature, the temperature at which the alloy may reset is necessarily close to body temperature. This thermal requirement obviates the possibility of heat bonding the liner to the stent at around a 250° C. temperature. Furthermore, the size of the covered stent that can be constructed in this manner is limited by the physics of heat conduction. That is, a 250° C. heat source must be at a suitable distance from the stent during the lamination process. The liners are laminated with the stent at a diameter less than deployed diameter, hence the size of the openings of the stent are smaller than if the liners were laminated at a larger stent diameter. Consequently, small diameter covered stents cannot be made in accordance with these teachings, nor can the liners be bonded to the stent. U.S. Pat. No. 6,156,064 to Chouinard teaches use of dip coating to apply polymers to self-expanding stents. Stents and stent-grafts are dipped into polymer-solvent solutions to form a film on the stent followed by spray coating and applying a polymeric film to the tube. Stent-grafts comprising at least three layers (i.e., stent, graft, and membrane) are taught to be constructed in this manner. Stents have also been covered with a continuous layer of elastic material. As taught in U.S. Pat. No. 5,534,287 to Lukic, a covering may be applied to a stent by radially contracting the stent, then placing it inside a tube with a coating on its inner surface. The stent is allowed to expand, thereby bringing it in contact with the coating on the tube. The surface of contact between the stent and the tube is then vulcanized or similarly bonded. No teaching is provided concerning the diameter of the tube relative to the fully deployed stent diameter. The patent specifically teaches in one embodiment the application of the coating on a stent in the expanded condition. The inventor does not teach how to eliminate or even reduce wrinkles in the stent cover. In fact, the patent teaches how to increase the thickness of the coating, a process that would only increase the occurrence of wrinkling. The patent teaches away from the use of a non-elastic material to cover the stent, and specifically teaches away from the use of a “Teflon®” (i.e., PTFE) tube. U.S. Patent Application 2004/0024448 A1 to Chang et al teaches covered stents with elastomeric materials including PAVE-TFE. Self-expanding stent-grafts made with this material, like those made of other materials in the art, are not wrinkle-free over the operating range of the devices. These coverings of self-expanding stents are typically applied to the stent in the fully-deployed state. Consequently, wrinkles are formed when the stent-graft is crushed to any significant degree. SUMMARY The present invention is an improved expandable implantable stent-graft device that provides a smooth flow surface over a range of operative expanded diameters. This is accomplished by applying a unique cover material to the stent through a unique technique that allows the cover to become wrinkle-free prior to reaching fully deployed diameter. The unique cover material then allows the device to continue to expand to a fully deployed diameter while maintaining a smooth and coherent flow surface throughout this additional expansion. In one embodiment the present invention comprises a diametrically self-expanding stent-graft device having a graft covering attached to at least a portion of the stent. The device is adapted to be constrained into a compacted diameter for insertion into a body conduit, which will produce wrinkles along its graft surface. However, when the device is unconstrained from the compacted diameter it will self-expand up to a fully deployed diameter with the graft being substantially wrinkle-free over diameters ranging from 50% to 100% of the fully deployed diameter. Further improvements in the present invention may include providing a fluoropolymer graft component, such as an ePTFE, in the form of either a coherent continuous tube or a film tube. The graft and stent may be combined together through a variety of means, including using heat bonding or adhesive, such as FEP or PMVE-TFE. By modifying the materials and/or the construction techniques, the range of wrinkle-free expansions can be increased to about 30%-100% or even wider ranges. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 a is a three-quarter isometric view of one embodiment of a covered stent of the present invention in the constrained state, having the cover mounted on the outside of the stent; FIG. 1 b is a three-quarter isometric view of the embodiment of a covered stent of the present invention of FIG. 1 a in the fully deployed state; FIG. 2 a is a transverse cross-section view of the embodiment of a covered stent of the present invention deployed to 30% of the fully deployed outer diameter of the device; FIG. 2 b is a transverse cross-section view of the embodiment of a covered stent of the present invention deployed to 50% of the fully deployed outer diameter of the device with the smooth gradual transition of the adhesive-stent cover interface shown in detail in an enlarged sectional view; FIG. 2 c is a transverse cross-section view of the embodiment of a covered stent of the present invention taken along line 2 c - 2 c of FIG. 1 b , deployed to 100% of the fully deployed outer diameter of the device with the smooth gradual transition of the adhesive-stent cover interface shown in detail in an enlarged sectional view; FIG. 3 a is a photomicrograph showing the inside of a covered stent of the present invention that is constrained in a partially deployed state of about 50% of the fully deployed outer diameter of the device; FIG. 3 b is a photomicrograph showing the inside of a covered stent of the present invention that is constrained in a partially deployed state of about 60% of the fully deployed outer diameter of the device; FIG. 3 c is a photomicrograph showing the inside of a covered stent of the present invention that is constrained in a partially deployed state of about 70% of the fully deployed outer diameter of the device; FIG. 3 d is a photomicrograph showing the inside of a covered stent of the present invention that is constrained in a partially deployed state of about 80% of the fully deployed outer diameter of the device; FIG. 3 e is a photomicrograph showing the inside of a covered stent of the present invention that is constrained in a partially deployed state of about 90% of the fully deployed outer diameter of the device; FIG. 3 f is a photomicrograph showing the inside of a covered stent of the present invention that is fully deployed; FIG. 3 g is a photomicrograph showing the inside of a covered stent of the prior art that is constrained in a partially deployed state of about 50% of the fully deployed diameter; FIG. 4 a is a transverse cross-section view of exemplary wrinkles in a cover on the outer surface of the stent; and FIG. 4 b is a transverse cross-section view of exemplary wrinkles in a cover on the inner surface of the stent. DETAILED DESCRIPTION The present invention addresses the problem of wrinkles in the covers in stent-grafts. The covers of self-expanding stent-grafts heretofore exhibited wrinkles when deployed to diameters smaller than the diameter at which the cover was applied to the stent, which is typically the fully deployed diameter. Inasmuch as body conduits are rarely the exact diameter of the stent-graft, rarely uniformly circular in cross-section, and rarely non-tapered, sections or entire lengths of self-expanding stent-grafts frequently are not fully deployed and hence present wrinkled surfaces to flowing blood or other body fluids. Furthermore, covered stents are often intentionally implanted at less than their fully deployed diameters in order to utilize their inherent radial expansion force to better anchor the devices against the host tissue, thereby preventing device migration in response to blood flow. Such practices come at the expense of having to tolerate devices with at least partially wrinkled covers. The present invention involves the use of a unique stent cover material, one that combines two seemingly mutually exclusive properties—being both strong enough to withstand the forces exerted by constant, cyclic blood pressure and also distensible enough to expand in response to the expansion forces exerted by a self-expanding stent. In addition, a unique manufacturing method had to be devised in order to utilize this material to construct a self-expanding stent-graft. The temperature-constrained shape-memory properties of self-expanding stents introduce significant processing challenges. Ultimately, a process was developed which entailed not only applying the cover to the stent in a cold environment, but also entailed bonding the cover to the stent at these cold temperatures. Referring to FIGS. 1 a and 1 b , the present invention is directed to implantable device 60 having a self-expanding stent component 63 with either an inner or outer cover 62 (or both), that is wrinkle-free over an operating diametric range of the device. The cover 62 has wrinkles 65 in the constrained state as shown in FIG. 1 a . The wrinkles disappear once the device self-expands to the diameter at which the cover was applied to the stent. The cover 62 remains wrinkle-free as the device 60 self-expands even further as shown in FIG. 1 b . The invention addresses the clinical problems associated with wrinkles in self-expanding stent covers while providing the minimum amount of covering material. Wrinkles are known to disrupt blood flow and become sites for clot deposition which can ultimately lead to graft thrombosis and embolus shedding. These sequelae may create serious clinical consequences, especially in organs such as the brain. The incorporation of a single, very thin cover enables a stent-graft device with a profile dictated primarily by the stent strut dimensions, not by the mass or volume of the cover. The present invention, therefore, provides a heretofore unavailable combination of deployment diameter for a given size stent-graft and a wrinkle-free cover surface over a wide range of deployed diameters. For use in the present invention, nitinol (nickel-titanium shape memory alloy) and stainless steel are preferred stent materials. Nitinol is preferred for its shape memory properties. The memory characteristics can be tailored for the requirements of the stenting application during the fabrication of the alloy. Furthermore, nitinol used to make the stent can be in the form of wire that can be braided or welded, for example, or it can be tubing stock from which a stent is cut. While nitinol offers a wide variety of stent design options, it should be appreciated that stainless steel and other materials may also be formed into many different shapes and constructs. Stent covers of the present invention are preferably durable and biocompatible. They may be seamless or contain one or more seams. The stent covering of the present invention has a low Young's modulus, which enables it to be distended with the minimal force that is exerted by a self-expanding stent. Furthermore, the covering is provided with a minimal (or non-existent) elastic recoil force so that after stent expansion the covering does not cause the stent-graft to decrease in diameter over time. The cover is also preferably thin. Thinness has the multiple benefits of reducing the introduction size of the device, maximizing the blood flow cross-section, providing less resistance to radial expansion, and introducing less elastic recoil. In a preferred embodiment, a nitinol stent is chilled and crushed to a diameter less than the fully deployed outer diameter. The chilling is desirable to help maintain the stent in the crushed state. The covering is then applied without creating wrinkles. The constrained diameter is selected according to the intended operating parameters of the device, such as about 90% of the fully deployed outer diameter or less, about 80% of the fully deployed outer diameter or less, about 70% of the fully deployed outer diameter or less, about 60% of the fully deployed outer diameter or less, and for most applications most preferably about 50% of the fully deployed outer diameter or less. While maintaining the device in the chilled state, the stent-graft is allowed to dry and then further crimped with a chilled crimping tool and transferred into a delivery catheter. The stent cover may consist of fluorinated ethylene propylene (FEP) coating the nodes and fibrils of ePTFE film. Most preferably, a cover of ePTFE, is used to practice the invention. Whereas ePTFE is known for its high tensile strength, that strength is imparted only in the direction of expansion. If the ePTFE material is not expanded in the orthogonal direction (i.e., the transverse direction in the case of films) during the processing of the material, the ePTFE material is extremely distensible in that direction. Such materials have both very low tensile strength and very low Young's modulus in the transverse direction. The low Young's modulus property enables the material to distend under low forces. Films used to construct articles of the present invention can be easily elongated in the transverse direction by hand, thereby demonstrating their low Young's modulus values. In the most preferred embodiments, therefore, the ePTFE materials are in the form of very thin, highly porous films that are highly distensible in the transverse direction. The combination of high porosity and thinness result in a cover material that occupies minimal volume of the device. Expanded PTFE stent covers may offer additional advantages by virtue of the ability to provide and control their porosity. Various agents or fillers can be added to the surface or within the pores of the material. Such agents and fillers may include but are not limited to therapeutic drugs, antithrombotic agents, and radio opaque markers. If desired, portions of or the entire ePTFE cover may optionally be rendered non-porous or non-permeable by densifying, filling the pores, or through any other suitable means. Preferably, to provide added stability to the material, the ePTFE material is raised above its crystalline melt point, that is, the ePTFE material is “sintered.” It is believed that thin ePTFE films possessing a thickness of less than about 0.25 mm are preferred for practicing the present invention. It is believed that even more preferred are films possessing a thickness less than about 0.1 mm. Preferred thin ePTFE films possess densities in the range of about 0.2 to about 0.6 g/cc. It is believed that more preferred thin ePTFE films have densities in the range of about 0.3 to about 0.5 g/cc. It is believed that preferred thin ePTFE films possess matrix tensile strengths in the range of about 70 to about 550 MPa and about 15 to about 50 MPa, in the longitudinal and transverse directions, respectively. It is believed that more preferred thin ePTFE films possess matrix tensile strengths in the range of about 150 to about 400 MPa and about 20 to about 40 MPa, in the longitudinal and transverse directions, respectively. The preferred film for use in practicing the present invention is a thin ePTFE film possessing a thickness of about 0.02 mm, a density of about 0.4 g/cc, longitudinal matrix strength of about 260 MPA, and a transverse matrix tensile strength of about 30 MPa. It is believed that preferred thin ePTFE films possess Young's modulus in the range of about 100 to about 500 MPa and about 0.5 to about 20 MPa, in the longitudinal and transverse directions, respectively. It is believed that more preferred thin ePTFE films possess Young's modulus in the range of about 200 to about 400 MPa and about 1 to about 10 MPa, in the longitudinal and transverse directions, respectively. The most preferred Young's modulus values of the film in the longitudinal and transverse directions are about 300 MPa and about 2 MPa, respectively. This film is exceedingly distensible in the transverse direction. The choice of film properties is largely dependent on the force the self-expanding stent exerts on the material during expansion. For example, stronger films may be used with stents that exert higher radial forces during self-expansion. To take advantage of the low Young's modulus of the film, the covered stent may be constructed with the low Young's modulus direction of the film oriented in the circumferential direction of the stent. The high strength direction of the film is therefore oriented in the axial direction of the stent. Preferably, the film is applied to the stent in the shape of a tube. A film tube is constructed by rolling multiple layers of the film around the circumference of a mandrel that is covered with a release material (such as Kapton film, part number T-188-1/1, Fralock Corporation, Canoga Park, Calif.). Preferably, three or fewer ePTFE film layers are applied, more preferably a single layer is applied wherein the overlap seam is narrow and comprises only two layers of the film. The film tube can be attached to the stent by suturing, gluing, and the like. Gluing is preferred, utilizing an adhesive or combination of adhesives by means such as spraying or dipping. It is preferred to dip coat a fully deployed stent with an adhesive, ensuring that the adhesive does not span the openings in the stent. Thermal or ambient cured adhesives can be used. When bonding the film tube to a shape memory metal stent using a thermally-activated adhesive, the adhesive should be curable at a temperature below the critical transition temperatures of the metal. Adhesives such as perfluoroethylvinylether-tetrafluoroethylene (PEVE-TFE) or perfluoropropylvinylether-tetrafluoroethylene (PPVE-TFE) are preferred. Terpolymers containing at least two of the following monomers are also preferred: PEVE, PPVE, perfluoromethylvinylether (PMVE), and TFE. Most preferably, the adhesive is perfluoromethylvinylether-tetrafluoroethylene (PMVE-TFE) material when bonding the cover to a nitinol stent. FIG. 2 a depicts a cross-section of the covered stent of the present invention that was constructed at 50% of the fully deployed outer diameter, crimped and transferred inside a delivery catheter, and then deployed to 30% of the fully deployed outer diameter of the device. The stent cover 62 can be attached to the outer surface of the stent by bonding it to stent struts 68 as shown in FIG. 2 a , thereby providing an outer stent cover 51 to the stent 63 . The cover 62 can alternatively be bonded to the inner surface of the stent as shown in FIG. 4 b , providing an inner stent cover 41 . The most preferred way to attach the film tube to the outer surface of the stent involves placing the film tube inside a rigid (e.g., glass) tube that has an inner diameter smaller than the fully deployed out diameter of the stent, then inserting the crimped stent inside the film tube and bonding the stent and film tube together. The film tube covering is first inserted inside the constraining tube without creating wrinkles. The ends of the film tube may be everted over the ends of the constraining tube. Preferably the ends are everted to the extent that modest tension is applied to the film tube, enough to hold the film tube taut and thereby keep the film tube free of wrinkles. As has been noted, the inner diameter of the constraining tube, and hence the constraining diameter, should be less than the fully deployed diameter of the device, such as 90% of the fully deployed outer diameter or less, about 80% of the fully deployed outer diameter or less, about 70% of the fully deployed outer diameter or less, about 60% of the fully deployed outer diameter or less, or about 50% of the fully deployed outer diameter or less. A nitinol stent is prepared by dip coating a thin layer of adhesive to its struts and allowing the adhesive to dry. The preferred adhesive is PMVE-TFE, such as that taught in Example 5 of US Patent Application 2004/0024448 to Chang et al. Contrary to practices in the prior art that teach bonding covers to stents at ambient or even highly elevated temperatures, the cover is applied to the stent at lower than ambient temperatures. Preferably, the stent is chilled and crimped in a cold chamber (e.g., the freezer compartment of a refrigerator). The low temperature process is desired in order to cool the stent in order to dimensionally stabilize it at a diameter less than the film tube diameter while the cover is attached. The crimped stent is next inserted inside the film tube, which is inside a rigid tube. The assembly is permitted to warm to ambient temperature. The stent expands, hence comes in intimate contact with the film tube, as it warms. The assembly is submerged in a solvent that activates the PMVE-TFE adhesive and then warmed above ambient temperature to evaporate the solvent, thus allowing the adhesive to solidify. The device inside the rigid tube is then again chilled in a freezer to a temperature at which at the device does not self-expand if unconstrained and then the stent-graft is removed from the tube. At this point, the stent-graft is further crimped using the chilled crimping machine, and transferred inside of a delivery catheter. Instead of crimping at this stage, alternatively the porous ePTFE cover of the stent-graft device may be rendered non-permeable. One method to do so can be achieved by dipping the device into a chilled dilute solution of elastomeric material, such as PMVE-TFE, PEVE-TFE, PPVE-TFE, or silicone. A dilute solution is preferred inasmuch as the solution becomes significantly more viscous when chilled to the same temperature as the device. Once the solution dries, the stent-graft can be crimped further, as previously described, and transferred inside of a delivery catheter. Therapeutic agents, fillers, or the like can be added to the stent cover, the adhesive used to bond the stent cover to the stent or the elastomer material used to render the cover non-permeable or any combination thereof. Stent-grafts made in this manner exhibit wrinkle-free coverings over the device diameter range extending from the diameter at which the covering was applied up to and including the fully deployed diameter. FIG. 2 b illustrates the wrinkle-free stent cover 62 (in this case, on the outer surface of the stent) at the diameter at which it was bonded to the stent struts 68 , thereby forming the covered stent device 60 . The thin cover 62 stretches and remains wrinkle free up to and including the fully deployed diameter as shown in FIG. 2 c . FIG. 2 c depicts a cross-section of the covered stent of FIG. 1 b . In order to achieve this device performance, the covering should be applied to the stent at a diameter smaller than the fully deployed diameter. This diameter should be no larger than the smallest intended diameter of the implanted device. Crushing the device below the diameter at which the cover was applied induces wrinkles in the stent cover. For example, crushing a device of the present invention to such a degree that it is small enough to be transferred to inside a delivery catheter will induce wrinkles in the stent cover. The wrinkles are no longer present once the deployed stent-graft reaches the diameter at which the cover was applied. Attaching the covering at an intermediate stent size means less crushing is necessary to decrease the stent-graft diameter for insertion into the delivery catheter. The likelihood of perforating the cover during the crushing process is reduced when less crushing is needed. A stent-graft with an inner cover can be fabricated with a film tube and an adhesive-coated stent as previously described. The stent can be chilled then crushed and constrained inside a constraining tube. The film tube can then be mounted onto a balloon, introduced inside the stent, pressed against the stent via inflating the underlying balloon, then bonded to the stent by immersing the assembly into the appropriate solvent for the adhesive, and then allowed to dry. The balloon is then deflated and the stent-graft plus the constraining tube are again chilled to enable removal of the constraining tube prior to further radial crushing of the stent-graft and loading the device into the delivery system. The present invention also minimizes flow disturbances caused by blunt stent strut profiles. As seen in FIG. 2 b and FIG. 2 c the adhesive material 22 bonded to stent strut 68 forms a smooth gradual transition where it attaches to stent cover 62 . In the absence of this transition, the stent strut 68 may present a blunt profile to the flowing blood. The wrinkle-free feature of articles of the present invention can benefit the performance of tapered stent-grafts. Tapered grafts are widely used in the treatment of aortoiliac disease. The present invention, which can include or not include a tapered stent and/or cover, can be implanted inside a tapered vessel without exhibiting wrinkles in the cover. That is, regardless of the shape of the starting materials, the device of the present invention can conform to become a tapered self-expanding stent-graft when deployed within a tapered body conduit. This allows tapered body conduits to be treated with non-tapered devices that are easier and less expensive to construct, without deploying an improperly sized stent-grafts. This also allows for a wider range of effective deployable sizes and shapes without the need to increase the number of different configurations of products. The present invention has particular value in very demanding, small caliber stenting applications. These are applications in which a cover is needed to either protect against plaque or other debris from entering the blood stream after balloon angioplasty or to seal an aneurysm. Perhaps the most demanding applications are those involving the treatment of carotid and neural vessels where even small wrinkles in the stent cover may create a nidus for thrombosis. Given the sensitivity of the brain, the consequences of such thrombus accumulation and possible embolization can be dire. Not only does the present invention overcome the challenging problem of providing a wrinkle-free cover in a viable stent-graft, it accomplishes this with a surprisingly minimal amount of covering material. It was unanticipated that such a distensible, thin, and low mass material could satisfactorily perform as a stent covering. The following examples are intended to illustrate how the present invention may be made and used, but not to limit it to such examples. The full scope of the present invention is defined in the appended claims. EXAMPLES To evaluate the examples, the following test methods were employed. Test Methods Assessment of Wrinkles Stent-graft device covers were visually examined without the aid of magnification at ambient temperatures. Microscopic examination might be warranted for very small devices. The ends of devices were secured within a hollow DELRIN® acetal resin block in order fix the longitudinal axis of the device at an angle of about 45° above horizontal which enabled viewing the inner surface of the stent-grafts. The devices were positioned to allow examination of free edge of the device and stent openings nearest the ends of the device. Stent-grafts that were not fully deployed were constrained inside rigid tubes during examination. Fully deployed devices were submerged in an about 37° C. water bath prior to examination. Alternatively, optical or scanning electron microscopy could be used to look for the presence or absence of wrinkles. Dimensional Measurements Stent and covered stent device outer diameters were measured with the aid of a tapered mandrel. The end of a device was slipped over the mandrel until the end fit snuggly onto the mandrel. The outer diameter of the device was then measured with a set of calipers. Optionally, a profile projector could be used to measure the outer diameter of the device while so placed on the mandrel. The fully deployed outer diameter was measured after allowing the self-expanding device to fully deploy in a 37° C. water bath for 30 seconds, then measuring the device diameter in the water bath in the manner previously described. For devices constrained inside constraining means having a round cross-section, the device outer diameter in the constrained state was taken to be the inner diameter of the constraining means. In order to examine a device at some percentage of the fully deployed diameter of the device, the fully deployed diameter must first be known. A length of a device can be severed from the entire device and its fully deployed diameter can be measured. For example, a length of the device can be released from the delivery catheter and its diameter measured after being fully deployed in a 37° C. water bath. Tensile Break Load, Matrix Tensile Strength (MTS), and Young's Modulus Determinations Tensile break load of the film was measured using a tensile test machine (Model 5564, Instron Corporation, Norwood, Mass.) equipped with flat-faced grips and a 10 N and 100 N load cells for the transverse and longitudinal values, respectively. The gauge length was 1 inch (2.54 cm) and the cross-head speed was 1 in/min (2.54 cm/min). Each sample was weighed using a Mettler AE2000 scale (Mettler Instrument, Highstown, N.J.), then the thickness of the samples was measured using a snap gauge (Mitutoyo Absulute, Kawasaki, Japan). A total of ten samples were tested. Half were tested in the longitudinal direction, half were tested in the transverse (i.e., orthogonal to the longitudinal) direction and the average of the break load (i.e., the peak force) was calculated. The longitudinal and transverse MTS were calculated using the following equation: MTS =(break load/cross-section area)*(density of PTFE)/bulk density of the film), wherein the density of PTFE is taken to be 2.2 g/cc. Young's modulus was determined from tensile test data obtained using a tensile test machine (Model 5500, Instron Corporation, Norwood, Mass.). The test was performed using a sample gauge length of 1 inch (2.54 cm) and a cross-head speed of 1 in/min (2.54 cm/min). A total of ten samples were tested. Half were tested in the longitudinal direction, half were tested in the transverse (i.e., orthogonal to the longitudinal) direction. Inventive Example 1 Tubular, self-expanding nitinol stents constructed using the pattern as described in FIG. 4 of U.S. Pat. No. 6,709,453 to Pinchasik et al., were obtained. The stents had an outer diameter of approximately 8 mm and lengths of about 44 mm. Six sections about 15 mm in length were cut from the stents. Each of the six sections was processed in the following manner. The stent was dip-coated with PMVE-TFE, a liquefied thermoplastic fluoropolymer as described in Example 5 of US Patent Application 2004/0024,448 of Chang, et. al. A short piece of silver-plated copper wire (approximately 0.5 mm in diameter) was fashioned into a hook and used to suspend the stent. The stent was submerged in a 3% by weight solution of PMVE-TFE and FC-77 solvent (3M Fluoroinert, 3M Specialty Chemicals Division, St Paul, Minn.). The dipped stent was removed from the solution and air-dried. The hook attached to the opposite end of the stent and the dipping process was repeated. The stent was next dipped in a 2% by weight solution of the fluoropolymer and the solvent, then air-dried. Once again, the hook was attached to the opposite end of the stent and the stent was again dipped into the 2% solution. This dipping process, therefore, consisted of four total dips, which yielded a uniform and uninterrupted layer of thermoplastic fluoropolymer on the stent struts. The amount of material applied weighed approximately 0.01 grams as determined by weighing the stent before and after the dipping process. A stent covering was made as follows. A 4.0 mm stainless steel mandrel was obtained. A 4 mm inner diameter thin-walled (wall thickness of about 0.1 mm) ePTFE tube was fitted over the mandrel. The purpose of this tube was to later assist in removing the stent cover from the mandrel. Next, a spiral wrapping of ribbon of polyimide sheeting (KAPTON®, Part Number T-188-1/1, Fralock Corporation, Canoga Park, Calif.) was applied on top of the ePTFE tube to completely cover a 75 mm length of the graft. A thin ePTFE film with the following properties was obtained: width of about 50 mm, matrix tensile strength in the longitudinal direction of about 256 MPa, matrix tensile strength in the transverse direction of about 31 MPa, a thickness of 0.02 mm, and a density of about 0.39 g/cc. (The tensile strengths in the longitudinal and transverse directions were 45 MPa and 5 MPa, respectively.) Young's modulus values of the film in the longitudinal and transverse directions were 282 MPa and 1.9 MPa, respectively. An approximately 80 mm length of the film was applied on top of the polyimide sheeting in the axial direction of the mandrel such that the ends of film were in direct contact with the thin-walled ePTFE tube. The corners of these ends were heat bonded to the thin-wall tube with the use of a local heat source (Weller Soldering Iron, model EC200M, Cooper Tools, Apex, N.C.) set to 343° C. With the film tacked in place in this manner, one layer of the film was wrapped about the circumference of the mandrel. Wrapping of the film was performed under minimal tension in order to avoid stretching the film. Approximately a 2 mm width of overlap region was created. The film layers in this overlap region were heat bonded together with the soldering iron set to 343° C. to form a seam. For this construction, therefore, the longitudinal direction of the film, which was its high strength direction, was oriented along the length of the mandrel. The weaker, transverse, film direction was oriented in the circumferential direction of the mandrel. A second layer of polyimide film was helically wrapped on top of the ePTFE film, completely covering it. This entire assembly was then placed in a forced air oven (Model NT-1000, Grieve Corporation, Round Lake, Ill.) set at 370° C. The assembly was removed from the oven after 7 minutes and allowed to cool. After cooling, the outer wrap of polyimide film was removed. The film tube, inner layer of polyimide film, and the thin-walled ePTFE tube, together, were carefully removed from the mandrel. The thin-walled ePTFE tube was everted, thereby removing it from the polyimide film. The polyimide film was then carefully removed from the ePTFE film tube. The stent and film tube were next assembled into a stent-graft. The ePTFE film tube was inserted inside a 60 mm long glass tube having an inner diameter of 4 mm and a wall thickness of 1 mm such that both ends of the film tube extended beyond the ends of the glass tube. The ends of closed forceps were then used to spread the ends of the film tube by placing them inside each end of the tube and then opening them. The film tube ends were everted over the outside of the glass tube. The film was tacky enough to secure the ends to the surface of the tube, thereby holding the wrinkle-free film tube in place. The glass tube with the ePTFE film tube inside it was placed in a conventional freezer set at approximately −15° C. Tools that would later be used to create the stent-graft, namely a set of tweezers and an iris-type stent crimping device, such as taught in US 2002/0138966 A1 to Motsenbocker, were also chilled in the freezer compartment. The chilled crimping device was used to reduce the diameter of the adhesive-coated stent uniformly along its length. The outer diameter of the stent was reduced to about 3 mm. Using chilled tweezers, the following procedure was performed inside the freezer compartment. The stent was removed from the crimper and transferred into the ePTFE film tube that was inside the chilled glass tube. The glass tube, film tube and stent were then removed from the freezer and allowed to warm to ambient temperature. The stent, by virtue of its shape memory characteristics, self-expanded as the assembly warmed. In doing so, the stent exerted radial force against the film tube, creating intimate contact between the stent and the film-tube along the length of the stent. Next, the stent cover was bonded to the stent. This assembly, still constrained by the 4 mm inner diameter of the glass tube, was then dipped in a container of FC-77 solvent for 40 seconds in order to activate the adhesive. The assembly was then allowed to dry for approximately 30 minutes while being warmed to 40° C. through the use of a halogen lamp. The assembly was allowed to cool to ambient temperature. In this way, a stent-graft device was created. The stent-graft device was pushed to one end of the glass tube until the end of the stent was flush with the end of the glass tube. The ePTFE covering was trimmed flush with the stent. The process was repeated to trim the opposite end of the stent-graft. With the stent-graft still inside the glass tube, the device was inspected to ensure thorough and uniform bonding between the stent cover and the stent and to verify the absence of wrinkles in the covering. The next step entailed loading the stent-graft into a delivery system. The stent-graft device, still constrained by the glass tube, was chilled in a freezer as previously described. The device was then transferred to inside a chilled iris crimper and further radially crushed to reduce its outer diameter to the desired delivery profile (i.e., crushed outer diameter), which was about 2 mm. The device was then transferred from the crimper into its intended delivery system. Thus, the device was prevented from self-expanding to its fully deployed outer diameter during the assembly and loading processes. The resultant stent-graft device had a delivery profile of about 2 mm and a fully deployed outer diameter of 8 mm. Photographs were taken of the device at various stages of deployment and subsequent re-crushing. The outer diameter of the device was characterized as a percentage of the fully deployed outer diameter, which was about 8 mm. The fully deployed device outer diameter was about 8 mm at both about 37° C. and at ambient temperature. It should be noted that this may not be the case for other types of nitinol alloys. FIGS. 3 a through 3 f are photomicrographs showing the inside of the six covered stents of this example. One device was transferred from its 2 mm delivery profile constraining sheath into a hollowed DELRIN® resin block with an inner diameter corresponding to about 50% of the fully deployed outer diameter of the device. This 50% of the fully deployed outer diameter corresponds to the outer diameter at which the device was made. Photomicrographs were taken of the end of the device as previously described. A representative image is shown as FIG. 3 a . This photomicrograph indicates the absence of wrinkles in the stent covering. Another device was transferred into a hollowed DELRIN® resin block with an inner diameter corresponding to about 60% of the fully deployed outer diameter of the device. A representative image is shown as FIG. 3 b . This photomicrograph indicates the absence of wrinkles in the stent covering. A third device was transferred into a hollowed DELRIN® resin block with an inner diameter corresponding to about 70% of the fully deployed outer diameter of the device. A representative image is shown as FIG. 3 c . This photomicrograph indicates the absence of wrinkles in the stent covering. The fourth and fifth stent-grafts were transferred into hollowed DELRIN® resin blocks with inside diameters of 80% and 90% of the fully deployed outer diameter of the devices, respectively; representative photomicrographs appear in FIGS. 3 d and 3 e , respectively. The coverings were wrinkle-free in both of these states, as indicated in the photomicrographs. The sixth device was fully deployed in a 37° C. water bath and then examined under a microscope. A representative image is shown as FIG. 3 f . This photomicrograph indicates the absence of wrinkles in the stent covering. Comparative Example 2 Film used in the construction of the six stent-graft devices of Example 1 was used to make a stent-graft in accordance with the teachings of the prior art. The cover was applied to a length of a stent of the type previously-described. In this case, the cover was attached to the stent in the fully deployed state under ambient conditions. The cover was applied in the same manner as described previously. The stent-graft device was then transferred to inside a chilled iris crimper as previously described and further radially crushed to reduce its outer diameter to the desired delivery profile (i.e., crushed outer diameter), which was about 2 mm. The device was then transferred from the crimper into its intended delivery system. Thus, the device was prevented from self-expanding to its fully deployed outer diameter during the assembly and loading processes. The resultant stent-graft device had a delivery profile of about 2 mm and a fully deployed outer diameter of 8 mm. This device was deployed within a hollow DELRIN® resin cavity, as described in Example 1. The diameter of the hole in the block corresponded to about 50% of the fully deployed diameter of the device. A representative photomicrograph of the crushed device appears as FIG. 3 g. The advantage of making the stent-graft device of the present invention in the above-described manner is clear when comparing FIG. 3 a with FIG. 3 g . Both photomicrographs were taken at 50% of the fully deployed outer diameter. FIG. 3 a , unlike FIG. 3 g , exhibits no wrinkles. FIG. 3 a demonstrates the wrinkle-free benefit of the present invention. On the other hand, FIG. 3 g demonstrates the wrinkles that result from crushing a film tube that was made at 100% of the deployed diameter, then crushed to 50% of the deployed diameter. Note the wrinkles in the leading edge of the cover in FIG. 3 g. While particular embodiments of the present invention have been illustrated and described herein, the present invention should not be limited to such illustrations and descriptions. It should be apparent that changes and modifications may be incorporated and embodied as part of the present invention within the scope of the following claims.

An improved stent-graft device is provided that delivers a smooth flow surface over a range of operative expanded diameters by applying a unique cover material to the stent through a technique that allows the cover to become wrinkle-free prior to reaching fully deployed diameter. The unique cover material then allows the device to continue to expand to a fully deployed diameter while maintaining a smooth and coherent flow surface throughout this additional expansion. Employed with a self-expanding device, when the device is unconstrained from a compacted diameter it will self-expand up to a fully deployed diameter with the graft being substantially wrinkle-free over diameters ranging from about 30-50% to 100% of the fully deployed diameter.

FIELD OF THE INVENTION AND RELATED ART The present invention relates to a developing apparatus which is mounted in an image forming apparatus to give developer to an electrostatic latent image formed on an image bearing member of the image forming apparatus, in order to develop the electrostatic latent image into a visible image. In the field of an image forming apparatus, it has been a common practice to blast the peripheral surface of a development sleeve to roughen the peripheral surface of the development sleeve, in order to enable the development sleeve to satisfactorily bear and carry developer. However, as a development sleeve increases in the length of usage, its peripheral surface is worn, and therefore, reduces in its performance in terms of developer conveyance. In recent years, therefore, there have been proposed various technologies for providing a development sleeve which is relative low in cost, and yet, highly durable and satisfactory in performance in terms of developer conveyance. One of these technologies is to provide the peripheral surface of a development sleeve with multiple grooves which are parallel to the axial line of the development sleeve and are uniform in interval, in order to improve the development sleeve in developer conveyance performance by making make these grooves bear developer. However, providing the peripheral surface of a development sleeve with multiple grooves, makes a groove portion of the peripheral surface of the development sleeve different in magnetic brush density from portions of the peripheral surface of the development sleeve, which do not have a groove. Therefore, as the development roller is rotated, the development area periodically changes in developer density with a pitch which is equal to the groove pitch. Consequently, low quality images, more specifically, images which appear nonuniform in density are outputted. Further, the periodicity of the nonuniformity corresponds to the groove pitch. In particular, in a case where a photographic image or the like, the substantial area of which is half-toned, the periodicity of the nonuniformity in density attributable to the groove pitch is very conspicuous. Thus, various remedial technologies for the above described problem have been proposed. One of them regulates the relationship among the moving speed of the peripheral surface (peripheral velocity) of an image bearing member, moving speed of the peripheral surface (peripheral velocity) of a development roller, and groove pitch of the development sleeve, to make the development sleeve higher in peripheral velocity or to reduce the development sleeve in groove pitch, in order to enable a developing device to output images which are significantly less in the above described periodic nonuniformity in density which is attributable to groove pitch, compared to the images outputted by a developing device in accordance with the prior art (Japanese Laid-open Patent Application 2002-132040 (Patent Document 1)). Another one structures a developing device so that the groove intervals become less than the magnetic brush height, in order to enable the developing device to output images which are significantly less in the above described periodic nonuniformity in density, which is attributable to the groove pitch (Japanese Laid-open Patent Application 2007-114317 (Patent Document 2)). However, increasing a development sleeve in peripheral velocity as disclosed in Patent Document 1 is problematic in that it is likely to cause toner to be scattered, and/or a fixed toner image to be scratched by magnetic brush. Therefore, it is likely to cause a developing device to output images of low quality. Further, reducing a development sleeve in groove intervals as disclosed in Patent Documents 1 and 2 increases the development sleeve in developer conveyance efficiency, making it necessary to reduce a developing device in the gap between its regulation blade and development sleeve. Thus, it is likely for foreign substance in developer to be stuck between the regulation blade and sleeve. SUMMARY OF THE INVENTION Thus, the primary object of the present invention is to provide a developing apparatus (device) which can output images which suffer significantly less from the nonuniformity in density attributable to groove pitch, compared to any conventional developing device, while being able to prevent foreign substances from becoming stuck between its regulating blade and development sleeve. According to an aspect of the present invention, there is provided a developing apparatus comprising a sleeve for carrying a developer to a position opposing an image bearing member, wherein said sleeve is provided with a plurality of groove portions extending in an axial direction of said sleeve; and a developing bias voltage applying device for applying a developing bias voltage to said sleeve, wherein said developing bias voltage applying device is capable of outputting, as the developing bias voltage, a voltage of a waveform having a cyclic period including an AC bias portion comprising an AC component and a DC component superimposed thereto, and a blank portion following the AC bias portion and consisting of a DC component, wherein a width L (m) of the groove, a peripheral speed Vs (m/s) of said developing sleeve, and a duration t1 (s) of the blank portion in one cyclic period of the developing bias voltage satisfy L/Vs<t1. Further features of the present invention will become apparent from the following description of exemplary embodiments. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view of the image forming apparatus in the first embodiment of the present invention, and shows the general structure of the apparatus. FIG. 2 is a sectional view of the developing apparatus (device) of the image forming apparatus in the first embodiment. FIGS. 3( a )- 3 ( c ) are drawing for showing the manufacture steps through which the development sleeve of the developing apparatus in this embodiment is manufactured, and FIG. 3( d ) is a sectional view of the peripheral surface portion of the development sleeve, at a plane indicated by a pair of arrow marks A and A′ in FIG. 3( c ). FIG. 4 is a drawing of the waveform of the development bias outputted by the electric power source of the developing apparatus in the first embodiment. FIG. 5 is a drawing which shows the relationship between the number of the blanks of the development bias outputted by the electric power source of the developing apparatus, and the performance of the developing apparatus, in the second embodiment of the present invention. FIG. 6 is a drawing of the development bias which the electric power source of the developing device in the second embodiment of the present invention outputs. FIG. 7 is a drawing of the development bias which the electric power source of the developing device in the third embodiment of the present invention outputs. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, few of the preferred embodiments of the present invention are described in detail with reference to appended drawings. By the way, the developing device in each of the following embodiments is for an image forming apparatus of the so-called tandem type. However, the present invention is also applicable to developing devices which are partially or entirely different in structure from those in the following embodiments. That is, an image forming apparatus by which a developing device in accordance with the present invention is employed may be of either the so-called tandem, or single-drum type. Further, it may be of either the intermediary transfer type, or direct transfer type. Further, the developer to be used by a developing device in accordance with the present invention may be two-component developer or single-component developer. Further, the present invention is applicable to various image forming apparatuses, such as various printers, copying machines, facsimile machines, multifunction image forming apparatuses, which are combinations of one of the image forming apparatuses in the following embodiments, additional devices, equipments, housing, etc. Embodiment 1 Image Forming Apparatus FIG. 1 is a schematic sectional view of the image forming apparatus in the first embodiment of the present invention. It shows the general structure of the apparatus. Referring to FIG. 1 , the image forming apparatus 100 is a full-color printer of the so-called tandem type, and also, of the recording medium conveyance belt type. That is, it has a recording medium conveyance belt 24 , and yellow (Y), magenta (M), cyan (C) and black (K) image forming stations PY, PM, PC and PK, which correspond in color to the images they form, one for one, and which are aligned in tandem along the recording medium conveyance belt 24 . To the recording medium conveyance belt 24 , sheets S of recording medium are sequentially conveyed from an unshown recording medium cassette with such a timing that the arrival of each sheet S at the image forming station P coincides with the arrival of a toner image on the photosensitive drum 10 Y at the image forming station P. In the image forming station PY, a yellow toner image is formed on the photosensitive drum 10 Y, and is transferred onto the sheet S on the recording medium conveyance belt 24 . In the image forming station PM, a magenta toner image is formed on the photosensitive drum 10 M, and is transferred onto the sheet S on the recording medium conveyance belt 24 . In the image forming stations PC and PK, cyan and black toner images are formed on the photosensitive drums 10 C and 10 K, respectively, and are transferred onto the sheet S on the recording medium conveyance belt 24 . After the transfer of the four toner images, different in color, onto the sheet S of recording medium, the sheet S is separated from the recording medium conveyance belt 24 with the utilization of the curvature of the recording medium conveyance belt 24 , and is sent into a fixing device 25 , through which the sheet S is conveyed while being subjected to heat and pressure. Consequently, the toner images are fixed to the surface of the sheet S. Then, the sheet S is discharged from the image forming apparatus 100 . The image forming portions PY, PM, PC and PK are the same in structure, although they are different in the color (yellow, magenta, cyan, and black) of the developer used by their developing devices 1 Y, 1 M, 1 C and 1 K, respectively. Hereafter, therefore, suffixes Y, M, C and K, which differentiate the image forming stations PY, PM, PC and PK, are not shown, and the four image forming stations PY, PM, PC and PK are described together as image forming stations P about their structure and operation. The image forming portion P is provided with a charging device 21 of the corona type, an exposing device 22 , a developing device 1 , first transfer charging device 23 , and cleaning device 26 , which are disposed in a manner to surround the peripheral surface of the photosensitive drum 10 as an image bearing member. The photosensitive drum 10 is provided with a photosensitive layer, which is the outermost layer of the photosensitive drum 10 . It is rotated in the direction indicated by an arrow mark R1 at a preset process speed (which is 300 mm/s in this embodiment). The process speed of the image forming apparatus 100 is the same as the peripheral velocity Vp of the photosensitive drum 10 . The charging device 21 of the corona type uniformly charges the peripheral surface of the photosensitive drum 10 to a preset negative potential level VD (pre-exposer level), by irradiating the peripheral surface of the photosensitive drum 10 with charged particles it discharges (corona discharge). The exposing device 22 writes an electrostatic image of an image to be formed, on the charged portion of the peripheral surface of the photosensitive drum 10 , by scanning the charged portion of the peripheral surface of the photosensitive drum 10 , with a beam of laser light, while modulating (turning on or off) the beam according to the image formation data obtained by separating the image to be formed, into monochromatic primary color images, with the use of its rotational mirror. The developing device 1 develops the electrostatic image into a toner image, by supplying the photosensitive drum 10 with toner. The first transfer charging device 23 is in the form of a blade. It presses on the recording medium conveyance belt 24 , forming thereby the first transfer station, that is, the portion in which a toner image is transferred from the photosensitive drum 10 onto the recording medium conveyance belt 24 , between the photosensitive drum 10 and recording medium conveyance belt 24 . As DC voltage which is opposite in polarity from the toner is applied to the first transfer charging device 23 , the toner on the peripheral surface of the photosensitive drum 10 is transferred onto the sheet S of recording medium. The toner remaining on the peripheral surface of the photosensitive drum 10 after the transfer is removed by the cleaning device 26 . Further, the developing device 1 is replenished with toner by the amount by which the toner in the developing device 1 has been used for an image forming operation, from a replenishment toner container 20 . It is two-component developer, which will be described later, that is used by the developing device in this embodiment. By the way, the application of the present invention is not limited to image forming apparatuses of the so-called direct transfer type, such as the image forming apparatus 100 in this embodiment, in which the toner images formed on the photosensitive drums 10 Y, 10 M, 10 C and 10 K, one for one, are directly transferred onto a sheet S of recording medium. That is, the present invention is also applicable to image forming apparatuses ( 100 ) of the so-called secondary transfer type, which are provided with an intermediary transferring member, in place of the recording medium conveyance belt 24 . In the case of an image forming apparatus of the so-called secondary transfer type, four toner images, different in color, are transferred from the photosensitive drums 10 Y, 10 M, 10 C and 10 K, one for one, onto the intermediary transferring member (primary transfer), and then, the four monochromatic toner images, different in color, of which a synthetic multicolor is made up, are transferred together (secondary transfer) from the intermediary transferring member onto a sheet S of recording medium. [Two-Component Developer] Next, the developer used by the developing device 1 in this embodiment is described. The developing device 1 uses two-component developer which is a mixture of nonmagnetic toner and magnetic carrier. The toner is made up of resinous coloring particles which is made up of bonding resin, coloring agent, and additives (which are added as necessary), and external additives such as minute particles of colloidal silica and/or the like. The toner used in the developing device 1 in this embodiment is made of negatively chargeable polyester resin, and is 7.0 μm in volume average particle diameter. The carrier is made up of one of such metallic substances as iron, nickel, cobalt, manganese, chrome, various rare-earth metals, and their alloys, which have been superficially oxidized or not, ferrite oxide particles, or the like. The method for manufacturing magnetic particles used as carrier does not need to be limited to a specific one. [Developing Device] Next, referring to FIG. 2 , the developing device 1 is generally described about its structure and operation. FIG. 2 is a sectional view of the developing device 1 of the image forming apparatus 100 in this embodiment. The developing device 1 has: a developer container (developing device housing) 2 , a regulation blade 9 , an electrical power source 11 as a development bias applying means, a partitioning wall 7 which is a part of the housing 2 , a first conveyance screw 5 , a second conveyance screw 6 , a development sleeve 8 , and a magnetic roller 8 ′. The housing 2 holds the two-component developer (which hereafter may be referred to simply as developer) which is a mixture of nonmagnetic toner and magnetic carrier. It has top and bottom chambers (development and stirring chambers 3 and 4 , respectively) partitioned by the portion wall 7 . The abovementioned first and second conveyance screws 5 and 6 are disposed in the top and bottom chambers, respectively. The development sleeve 8 is a developer bearing member. It is disposed on the opposite side of the development area from the photosensitive drum 10 so that its peripheral surface opposes that of the photosensitive drum 10 . More specifically, the development sleeve 8 is rotatably disposed in such a manner that it is partially exposed through the opening, with which the photosensitive drum 10 side of the housing 2 is provided. The space between the photosensitive drum 10 and development sleeve 8 is the development area (development station) through which developer transfers from the development sleeve 8 onto the photosensitive drum 10 . The width of the development area, that is, the width of the gap (SD gap) between the development sleeve 8 and photosensitive drum 10 , is roughly 250 μm. The development sleeve 8 is a cylindrical component made of a nonmagnetic substance (aluminum or the like), and is 20 mm in diameter. The magnetic roller 8 ′ is a magnetic field generating means. It is nonrotationally disposed in the hollow of the development sleeve 8 . It has a development pole S1, and developer conveyance poles S2, N1, N2 and N3. The development sleeve 8 is disposed so that the magnetic poles N3 and N2, which are the same in polarity, are positioned next to each other in the housing 2 . Since the magnetic field generated by the magnetic pole N3, and that generated by the magnetic pole N1 repel each other. Therefore, the developer separates from the peripheral surface of the development sleeve 8 , in the stirring chamber 4 . In operation, as the development sleeve 8 is rotated in the direction indicated by an arrow mark R2, the two-component toner is borne by the development sleeve 8 , forming a toner layer (magnetic brush). Then, the toner layer is regulated in thickness by the regulation blade 9 . Then, the development sleeve 8 conveys the two-component developer on the development sleeve 8 to the development area where the development sleeve 8 opposes the photosensitive drum 10 , and develops the electrostatic latent image on the peripheral surface of the photosensitive drum 10 by supplying the electrostatic latent image with the developer. The regulation blade 9 is a developer regulating member. It is at the upstream edge of the opening of the developing device housing 2 in terms of the rotational direction of the development sleeve 8 , and opposes the development sleeve 8 . Thus, as the development sleeve 8 is rotated, the toner layer on the peripheral surface of the development sleeve 8 comes into contact with the regulation blade 9 , being thereby made uniform in thickness: the magnetic blush is regulated in height. That is, the regulation blade 9 regulates in thickness the developer layer on the peripheral surface of the development sleeve 8 . It is a long and narrow rectangular piece of nonmagnetic substance (aluminum or the like), and is positioned so that its long edges become parallel to the lengthwise direction of the development sleeve 8 . As the developer layer, which is a mixture of toner and carrier, is moved through the gap between the regulating edge (free edge) of the regulation blade 9 , and the peripheral surface of the development sleeve 8 , it is regulated in thickness. Then, it is conveyed to the development area. The amount by which the tip portion of a magnetic brush formed of the developer is cut off (magnetic brush is regulated in height), and the amount by which the developer is conveyed to the development area, are adjusted by the alteration of the gap between the regulating edge of the regulation blade 9 and the development sleeve 8 . In this embodiment, the amount, per unit area, by which developer is allowed to remain on the peripheral surface of the development sleeve 8 , by the regulation blade 9 is 30 mg/cm 2 . Further, the peripheral velocity ratio R of the development sleeve 8 relative to the photosensitive drum 10 is 175%. Referring to FIG. 2 , the partition wall 7 is in the internal space of the developing device housing 2 . In terms of the vertical direction of the housing 2 , it is roughly in the middle of the housing 2 . It extends in the rearward-frontward direction of the housing 2 , partitioning the internal space of the housing 3 into the development chamber 3 (top chamber) and stirring chamber 4 (bottom chamber). The first and second conveyance screws 5 and 6 are means for circulating the developer, while stirring the developer, in the housing 2 . They are in the development chamber 3 and stirring chamber 4 , respectively. The first conveyance screw 5 is in the bottom portion of the development chamber 3 , and is roughly parallel to the development sleeve 8 . It conveys the developer in the development chamber 3 toward one of the lengthwise ends of the development chamber 3 , in the direction parallel to its axial line, by being rotated. The second conveyance screw 6 is in the bottom portion of the stirring chamber 4 , and is roughly parallel to the first conveyance screw 5 . It conveys the developer in the stirring chamber 4 toward the other lengthwise end of the housing 2 , that is, in the opposite direction from the direction in which the developer is conveyed by the first conveyance screw 5 , in the direction parallel to its axial line, by being rotated. As the developer in the housing 2 is conveyed by the rotation of the first and second conveyance screws 5 and 6 in the direction parallel to the rotational axis of the two screws 5 and 6 , toward one of the lengthwise ends of the development chamber 3 , and the other, respectively, it is circulated between the development chamber 3 and stirring chamber 4 through the unshown passages which are at the lengthwise ends, one for one, of the housing 2 and connect the development chamber 3 and stirring chamber 4 . While the developer is circulated between the development chamber 3 and stirring chamber 4 , it is supplied to the peripheral surface of the development sleeve 8 from the development chamber 3 , through the gap between the regulation blade 9 and partition wall 7 , by the rotation of the first conveyance screw 5 . To describe in detail, the first and second conveyance screws 5 and 6 are made up of a rotational axle, and an unshown spiral blade fitted around the rotational axle. Both the rotational axle and spiral blade are made of a nonmagnetic substance. The first and second conveyance screws 5 and 6 are 20 mm in diameter, and 20 mm in pitch. Both the first and second conveyance screws 5 and 6 are rotationally driven at 600 rpm. [Grooves of Development Sleeve] Next, referring to FIG. 3 , the grooves with which the peripheral surface of the development sleeve 8 is provided are described. FIGS. 3( a )- 3 ( c ) are drawings for showing the steps through which the development sleeve 8 of the developing device 1 in this embodiment is manufactured. FIG. 3( d ) is a sectional view of one of the grooves and its adjacencies, at a plane indicated by arrow marks A and A′ in FIG. 3( c ). Referring to FIG. 3( d ), the peripheral surface of the development sleeve 8 is provided with 50 grooves 8 a , which extend in the direction parallel to the axial line of the development sleeve 8 . The grooves 8 a are V-shaped in cross-section. They are 50 μm in depth, and 90° in bottom angle. In terms of the lengthwise direction of the development sleeve 8 , they are parallel to each other. In terms of the circumferential direction of the development sleeve 8 , their intervals are the same. The following is an example of sequential steps through which the development sleeve 8 in this embodiment is manufactured. First, referring to FIG. 3( a ), a piece of unprocessed aluminum tube, which is 20 mm in diameter, is prepared. Next, a preset number of grooves 8 a which are preset in shape, depth, bottom angle, etc., are formed by drawing (aluminum tube through die), etching, or the like, as shown in FIG. 3( b ). Lastly, the lengthwise end portions of the aluminum tube, in terms of the direction parallel to the axial line of the development sleeve 8 , which are not to be coated with developer, are machined to rid the lengthwise end portions of the grooves 8 a , as shown in FIG. 3( c ), in order to reduce the lengthwise end portions in developer conveyance performance. That is, the lengthwise end portions of the development sleeve 8 are machined into groove-less portions 8 b. In a case where the groove 8 a is V-shaped in cross-section, 50 μm in depth, and 90° in bottom angle, the width L of the groove 8 a is 100 μm. Further, the length of time T it takes for one of the grooves 8 a to pass (relative movement) a given point (phase) in the development area when the development sleeve peripheral velocity ratio R is 175% is 190 μs, which is obtainable with the use of the following equation: Length T of time=groove width L /(development sleeve peripheral velocity ratio R ×peripheral velocity Vp of photosensitive drum). [Development Bias] Next, referring to FIG. 4 , the development bias used by the developing device 1 in this embodiment is described. FIG. 4 is a drawing of the waveform of the development bias which the electrical power source 11 of the developing device 1 in the first embodiment outputs. The electrical power source 11 is a development bias applying means. It applies to the development sleeve 8 , a development bias which is a combination of an AC component and a DC component. In this embodiment, the AC component of the development bias is rectangular in waveform, and is 10 kHz in frequency. Referring to FIG. 4 , this development bias has blank portions, that is, portions having no AC component, which are created by removing the AC component, with preset intervals. In this specification, the pulses which were rectangular in waveform, and were occupying the blank portions of the development bias before they were eliminated with preset interval, are referred to as “blank pulses”. That is, the pulses of the AC components, which were removed from the AC component, are referred to as “blank pulses”. Further, the portion of the development bias, from which the AC component was removed, that is, the portion of the development bias having only the DC component, are referred to as “blank portion”. That is, in terms of waveform, each period of the development bias which the electrical power source 11 outputs has an alternating portion (AC portion), and a nonalternating portion (blank portion) which follows the alternating portion. The alternating portion is made up of a combination of the AC and DC components. The nonalternating portion (blank portion) is made up of only the DC component. Referring to FIG. 4 , the waveform of the development bias used in this embodiment is a single blank pulse waveform (which hereafter will be referred to as SBP), that is, a combination of two rectangular portions (which is equivalent to single period of AC component), and a blank portion (no pulse) which follows the rectangular portions. By the way, in this specification, the number of pulses which are rectangular in waveform is the number of pulses which are equivalent to one half of each period of the AC component. The length of time the development bias remains blank in each period is referred to as blank time t1, or simply, blank time t1. The sum of the length of time electric field is generated by the development side of the alternating portion of each period of the development bias is referred to as development time t2, or simply, development time t2. Further, the ratio (which hereafter will be referred to as “duty ratio”) of the electric field generated by the development side (developer supplying side) of the alternating portion, relative to the electric field generated by the developer recovering side (developer pulling side), was 50%. Here, the electric field on the developing side means the electric field generated by the alternating portion of each period of the development bias so that it causes toner to jump from the development sleeve 8 (developer bearing member) onto the photosensitive drum 10 (image bearing member) in each period of the development bias. The electric field on the developer recovery side means the electric field generated by the alternating portion of each period of the development bias so that it causes toner to be pulled back from the photosensitive drum 10 onto the development sleeve 8 . [Experiments Related to Extent of Nonuniformity in Image Density Attributable to Groove Pitch] First, the conditions under which experiments were conducted are described. Development bias was varied in blank pulse count (which hereafter may be referred to simply as blank count) to find out the relationship between the extent of the periodic nonuniformity in density, from which some images suffer, and the pitch of the groove 8 a (groove pitch). More concretely, half-tone images of A3 size were outputted, as test images, with the use of the image forming apparatus 100 , and various development biases in accordance with the present invention, which have a SBP waveform and different in blank count, and conventional development bias, that is, a bias which is rectangular in waveform and has no black pulse. A section (10 mm×400 mm) of each of the outputted images of the test image was scanned with a scanner ES-10000G (product of Epson C., Ltd.) at a resolution of 600 dpi. Then, the data obtained by the scanning were analyzed with the use of FFT (Fast Fourier Transform) to obtain the frequency component (frequency characteristics) of the periodic horizontal stripes which each of the outputted images of the test image had. In this embodiment, the development sleeve 8 was 20 mm in diameter, and 50 in the number of grooves 8 a , and 175% in peripheral velocity ratio relative to the photosensitive drum 10 . Therefore, it was possible that the nonuniformity in image density attributable to groove pitch would appear at a pitch of 0.718 mm (=20×π/50/1.75). Since the process speed of the image forming apparatus 100 , that is, the peripheral surface of the photosensitive drum 10 , is 300 mm/s, the most conspicuous portion of the nonuniformity will be related to 418 Hz which is specific to groove pitch. Referring to Table 1, as for the conditions under which experiments were carried out, in Experiment 1-1, the waveform of the development bias was a SBP, the blank count of which was 2 (pulses); in Experiment 1-2, the waveform of the development bias was a SBP, the blank count of which was 4 (pulses); and in Experiment 1-3, the waveform of the development bias was a SBP, the blank count of which was 8 (pulses). Further, for comparison, a bias, which is rectangular in waveform, that is, a bias, the blank count of which is zero, was used as the development bias. TABLE 1 Freq. of No. Rectang. of Long period Developing Blank Portions Blank Freq. time time t1 Peak Waveform Duty % kHz pulses kHz μ s μ s value Emb. 1-1 SBP 50 10 2 5 50 100 0.05 Emb. 1-2 SBP 50 10 4 3.3 50 200 Non Emb. 1-3 SPB 50 10 8 2 50 400 Non Comp. Ex. Rectangular 50 10 0 — — 0 0.20 Next, the results of the experiments are described. Referring to Table 1, the frequency of the rectangular portions (portions with rectangular waveform) is equal to the frequency of the AC component of the development bias. The long period frequency is the frequency of the long period, that is, the period made up of an alternating portion and a blank portion. Peak values are the values which correspond (occurred) at 418 Hz which is specific to the groove pitch. As will be evident from Table 1, in Comparative Experiment 1, that is, when the development bias was a simple alternating bias which is rectangular in waveform, the value obtained by analyzing the data of the images of the test image was largest (0.20) at 418 Hz which is specific to the groove pitch. In this case, the nonuniformity in image density attributable to the groove pitch was confirmable even with naked eye. In comparison, in Experiment 1-1, in which the blank count was 2 (pulses), the peak value was 0.05, which was smaller than that in Comparative Experiment 1. Further, in Experiments 1-2 and 1-3, in which the blank count was 4 and 8 (pulses), respectively, no peak was detected; the peak value was zero. Thus, it is evident that a development bias, such as those used in Experiments 1-1, 1-2 and 1-3, which have a blank portion, can reduce nonuniformity in image density attributable to groove pitch, compared to a development bias, such as the one in Comparative Experiment 1, which has no blank portion (has plain rectangular waveform). It is also evident that increasing the blank time t1 by increasing blank count as in Experiments 1-1, 1-2 and 1-3, can enhance the effect of the development bias having a blank portion. [Principle of Occurrence of Nonuniformity in Image Density Attributable to Groove Pitch, and Mechanism of Reduction of Nonuniformity] Next, the principle of occurrence of nonuniformity in image density attributable to groove pitch, and the mechanism which reduces the nonuniformity, are described. First, why the groove pitch affects an image forming apparatus (developing device) in terms of image quality, more specifically, nonuniformity in density, is described. In the case of the development sleeve 8 , the peripheral surface of which is provided with the grooves 8 a , the groove portions 8 a of its peripheral surface, and the portions of its peripheral surface, which have no groove 8 a , are different in the magnetic brush density, being therefore different in development performance (ability to develop latent image). Therefore, the portions of the outputted image of the test image, which were developed by the portions of the peripheral surface of the development sleeve 8 , which have the groove 8 a , are higher in density, than those developed by the portions of the peripheral surface of the development sleeve 8 , which have no groove 8 a . That is, the image forming apparatus outputs images which are not uniform in density, and the nonuniformity of which reflects the groove pitch. Next, the mechanism which reduces an image forming apparatus in nonuniformity in image density, which is attributable to groove pitch is described. The blank portion of the development bias, which is made up of only DC component, is lower in development performance than the alternating portion of the development bias, which is made up of a combination of a DC component and an AC component. However, providing a development bias with a blank portion makes it possible for the timing with which the groove 8 a passes a given point (phase) in the development area, to coincide with the timing with which the blank portion is outputted. Therefore, it is less likely for the portions of an image developed by the groove portion 8 a , and those developed by the portion with no groove 8 a , to be significantly different in density. That is, images formed with the use of development bias having a blank portion are less likely to suffer from nonuniformity in density attributable to groove pitch. Further, extending the blank time t1 makes it more likely for the timing with which the groove portion 8 a passes a given point in the development area, to coincide with the timing with which the blank portion of the development bias is outputted. Therefore, it can enhance the effect of the blank time t1 upon the reduction of the nonuniformity in image density attributable to groove pitch. Making the blank time t1 longer than the groove portion transit time T (=190 μs), as in Experiment 1-1, 1-2 and 1-3, makes it virtually impossible to detect the peak value, that is, makes the peak value virtually zero. In other words, it can enhance the effects of the development bias in this embodiment, upon the reduction of the nonuniformity in image density attributable to the groove pitch. That is, satisfying an inequality (groove portion transit time T<blank time t1) enhances the effect of the development bias in this embodiment, upon the reduction of the nonuniformity in image density attributable to the groove pitch. By the way, even if the condition (groove portion transit time T<blank time t1) is satisfied, it is possible that the groove portion transit time T will overlap with the timing with which an electric field is generated by the development pulse of the alternating portion of the development bias. However, as long as the condition (groove portion transit time T<blank time t1) is satisfied, it does not occur that the groove portion transit time T overlaps with the electric field generated by the development side pulse by no less than a single period of the development bias, and therefore, it is effective to reduce in severity the nonuniformity image density attributable to groove pitch. Further, in this embodiment, the development bias is structured so that the frequency of its long period does not become an integer multiple of the frequency (groove pitch frequency) with which a given point on the peripheral surface of the photosensitive drum 10 is passed by the grooves 8 a . Therefore, even if the electric field which corresponds to the development side of the development bias happens to act on the groove portion 8 a , it is only by an amount equivalent to a single pulse, and it does not occur that it is always only the electric field generated by the development pulse that acts on the groove portion 8 a . Therefore, the development bias in this embodiment is still effective to reduce in severity the nonuniformity in image density attributable to groove pitch. Further, the comparison among Experiments 1-1, 1-2 and 1-3 revealed that lengthening the blank time t1 by increasing the blank count enhances the effects of the development bias upon the reduction in severity of the nonuniformity attributable to groove pitch. However, if the blank count is excessive, it is possible that the development bias reduces the developing device 1 in performance. Therefore, the relationship between the blank count and developmental performance was obtained by experiments. FIG. 5 shows the results of the experiments, and shows the relationship between the blank count and the development efficiency [%]. The development efficiency was obtained with the use of a formula ({(post-charge potential level−post-exposure potential level)/(development DC−post-exposure potential level)×100}). Here, “post-charge potential level” is the potential level of a given exposed point of the peripheral surface of the photosensitive drum 10 after the adhesion of toner to the given exposed point by development, and is affected by the state of toner in terms of amount of electric charge. “Post-exposure potential level”, means the potential level of a given exposed point of the peripheral surface of the photosensitive drum 10 prior to development. “Development DC” means the potential level of the DC component of the development bias. Referring to FIG. 5 , the development bias, the waveform of which is SBP, was excellent in development efficiency as long as its blank count was in a range of 2-10 pulses. However, in a case where its blank count is no less than 10 pulses, it is rather low in development efficiency. That is, in a case where the ratio between the development time t2 and blank time t1 is no less than 1:10 (blank count is no less than 10), the development bias, the waveform of which is SBP, was conspicuously low development efficiency. On the other hand, in the case of WBP, which will be described later, it was excellent in development efficiency as long as its blank count was in a range of 2-20 pulses. Therefore, from the standpoint of keeping the developing device 1 excellent in development efficiency, it is desired that the blank time t1 and development time t2 are set so that their relationship satisfies a condition (t1/t2≦10). Further, in a case where the blank count is 2 as in Experiment 1-1, the peak value attributable to groove pitch was 0.05. Thus, from the standpoint of reducing the nonuniformity in image density attributable to groove pitch, the blank count is set to a value in a range of 4-10, if the waveform of the development bias is SBP. As described above, the electric power source 11 of the developing device 1 in this embodiment outputs a development bias, each period of which in terms of waveform is a combination of an alternating portion and a blank portion (nonalternating portion). The alternating portion is a combination of an AC component and a DC component, and a blank portion has only a DC component. The groove portion transit time T and blank time t1 are set so that they satisfy the relationship (groove portion transit time T<blank time t1). Therefore, the timing with which a given groove 8 a passes a given point in the development area is likely to coincide with the timing with which the blank portion of the development bias is outputted. Therefore, a portion of an image, which is developed by the groove portion 8 a , and a portion of an image, which is developed by the portion with no groove 8 a , is less likely to be different in density. That is, this embodiment can reduce a developing device in the nonuniformity in image density, which is attributable to the groove pitch. Further, in the case of the development bias in this embodiment, the blank time t1 and development time t2 are set to satisfy a formula (t1/t2≦10). Therefore, this embodiment can reduce the developing device 1 in the nonuniformity in image density, which is attributable to the groove pitch, while keeping the developing device 1 at an excellent level in terms of development efficiency. Embodiment 2 Next, referring to FIG. 6 , the output of the electric power source 11 of the developing device 1 in the second embodiment of the present invention is described. FIG. 6 is a drawing of the waveform of the development bias outputted by the electric power source 11 of the developing device 1 in the second embodiment. The image forming apparatus 100 and developing device 1 in this embodiment are the same in structure and operation as those in the first embodiment. Therefore, their structural components which are similar to the counterparts in the first embodiment are given the same referential codes as those given to the counterpart, and are not described here, except for their characteristic features. In the first embodiment, a SBP was used as the waveform for the development bias. It was varied in the number of blank portions to find out the relationship between the change in the number of blanks and the changes in the severity of the nonuniformity in density, which are attributable to groove pitch. In comparison, the development bias used by the developing device 1 in this embodiment, is a bias, the waveform of which is such that two alternating portions (4 pulses: two periods of AC component), which are rectangular in waveform, are followed by two blank portions (2 blank pulses: two periods of DC component), as shown in FIG. 6 . This type of waveform will be referred to as a double-blank waveform (WBP). In the experiments carried out to test the development bias in this embodiment, variables such as development time t2 were changed to observe the changes in the severity of the nonuniformity in image density, which is attributable to groove pitch. In FIG. 6 , the development time t2 is the sum of duration of two development pulses of the alternating portion, that is, duration of two downwardly protruding portions of the waveform. Referring to Table 2, the waveform of the development bias used by the developing device 1 in this embodiment is the WBP. The developing device 1 in this embodiment was put through Experiments 2-1 and 2-2, in which the development bias was varied in pulse count, blank (pulse) count, long period count, and development time t2 so that the blank time t1 became 200 μs. More concretely, in Experiment 2-1, the frequency of the alternating portion which is rectangular in waveform was 10 kHz, and blank count, long period frequency, and development time t2 were set to 4, 2.5 kHz, and 100 μs, respectively. For Experiment 2-2, the frequency of the alternating portion which is rectangular in waveform was set to 5 kHz, and blank count, long period frequency, and development time t2 were set to 2, 1.7 kHz, and 200 μs, respectively. That is, Experiment 2-2 was made the same in blank time t1 as Experiment 2-1, and longer in development time t2 than Experiment 2-1. Further, in both Experiments 2-1 and 2-3, the blank time t1 was set so that the condition (groove pass time T<blank time t1) is satisfied. TABLE 2 Freq. of No. Rectang. of Long period Developing Blank Portions Blank Freq. time time t1 Peak Waveform Duty % kHz pulses kHz μ s μ s value Emb. 2-1 WBP 50 10 2 2.5 100 200 Non Emb. 2-2 WBP 50 5 4 1.7 200 200 0.05 Next, the results of the experiments are described. As will be evident from Table 2, in Experiment 2-1, unlike in Experiment 1-2 in the first embodiment, in which the waveform of the development bias is SBP, the waveform of the development bias in the second embodiment is WBP, being therefore longer in development time t2. However, the peak value was 0. That is, the development bias in Experiment 2-1 was also effective to reduce the nonuniformity in image density attributable to groove pitch, as the development bias in the first embodiment. On the other hand, in Experiment 2-2, such nonuniformity in image density that is attributable to groove pitch and is detectable even with naked eyes was not present. However, the peak value was 0.05 which was attributable to groove pitch. That is, the development bias used in Experiment 2-1 was better in results than that in Experiment 2-2. More specifically, although the development bias in Experiment 2-2 satisfied the required relationship between the groove portion transit time T and blank time t2 (groove portion transit time T<blank time t2), and therefore, was effective to reduce the nonuniformity in image density attributable to groove pitch. However, the development bias in Experiment 2-1, which was structured as described above, was more effective to reduce the nonuniformity in image density attributable to groove pitch than the development bias in Experiment 2-2. To think about the reasons why the development bias in Experiments 2-1 was different in peak value from that in Experiment 2-2, although the development bias in Experiment 2-2 satisfied the condition (groove portion transit time T<blank time t2), it was longer in development time t2 than the development bias in Experiment 2-1. This seems to be the reason why it was less effective to reduce the nonuniformity in image density attributable to groove pitch than the development bias in Experiment 2-1. That is, even if a development bias is structured so that its blank time t1 is extended to satisfy the relationship (groove portion transit time T<blank time t1), it is possible that electric field will be generated by the pulse on the development side while the groove portion 8 a is moving through the development area. In Experiment 2-2, therefore, the development bias was structured so that it becomes less in the number of the portions which are rectangular in waveform, and the long period frequency, and longer in the development time t2, than the development bias in Experiment 2-1. Therefore, it was inferior in the effectiveness to reduce the nonuniformity in image density attributable to groove pitch, to the development bias in Experiment 2-1. Therefore, from the standpoint of reducing the occurrence of the nonuniformity in image density attributable to groove pitch, it is desired to set a minimum value for the groove portion transit time T, and also, set the blank time t1, development time t2, and groove portion transit time T so that the condition (development time t2<groove portion transit time T<blank time t1). Structuring the development bias as described above makes it possible to prevent the problem that the groove portion 8 a is subjected to only the electric field generated by the pulses on the development side, and therefore, can ensure that the development bias is effective to reduce the nonuniformity in image density attributable to groove pitch. In Experiment 2-1, development time t2 (=100 μs)<groove portion transit time T (=190 μs)<blank time t1 (=200 μs). That is, the condition (development time t2<groove portion transit time T<blank time t1) was satisfied. Therefore, the development bias in Experiment 2-1 reduces the nonuniformity in image density attributable to groove pitch. In this embodiment, the waveform of the development bias was a WBP. However, as long as the condition (development time t2<groove portion transit time T<blank time t1) is satisfied, a development bias, the waveform of which is other than a WBP or a SBP, can be used as the development bias. For example, the waveform for the development bias may be the so-called triple blank pulse waveform, that is, a waveform structured so that three cycles (six pulses) of AC bias which is rectangular in waveform is followed by a blank portion. As described above, the developing device 1 in this embodiment is structured so that it satisfies the condition (development time t2<groove portion transit time T<blank time t1). Therefore, it can prevent the problem that it is only the electric field generated by the development side of the development bias that the groove portion 8 a is subjected. Therefore, it is ensured that the developing device 1 in this embodiment is effective to reduce the nonuniformity in image density attributable to groove pitch. Embodiment 3 Next, referring to FIG. 7 , the output of the electric power source 11 of the developing device 1 in the third embodiment of the present invention is described. FIG. 7 is a drawing which shows the waveform of the development bias which the electric power source of the developing device 1 in this embodiment outputs. The image forming apparatus 100 and developing device 1 in this embodiment are similar in basic structure and operation, to the image forming apparatuses 100 and developing devices 1 in the first and second embodiments. Therefore, their components which are the same or similar in function, as or to, the counterparts in the first and second embodiments, are given the same referential codes as those given to the counterparts, and are not described here, except for their characteristic features in this embodiment. In the second embodiment, the development bias was structured to satisfy the condition ((development time t2<groove portion transit time T<blank time t1) in order to further reduce the nonuniformity in image density attributable to groove pitch, compared to the development bias in the first embodiment. Here, the parameters for setting the development time t2 are the frequency of the alternating portion which is rectangular in waveform, frequency of the long period, pulse count of the alternating portion of the single period, which is rectangular in waveform, and duty ratio. These parameters can be adjusted to set the development time t2 to make the development time t2 desirable for satisfying the condition (development time t2<groove portion transit time T). Referring to FIG. 7 , in this embodiment, the duty ratio of the alternating portion of the development bias, the waveform of which is a WBP, was set to 60%. That is, the ratio between the development time t2 and recovery time (total length of time developer recovering electric field is active) was set to 4:6. In this case, therefore, the ratio between the strength of the developing electric field and the strength of the developer recovering electric field is 6:4. By the way, the development time t2 in FIG. 7 is the sum of the length of time the developing electric field is generated by the development side of the alternating portion of the development bias, that is, the portions which correspond to the two downwardly protruding portions of the waveform. As described above, by structuring the development bias so that the duty ratio of the alternating portion of the development bias becomes 60%, it is possible to reduce the development time t2 while keeping the development bias the same in development performance, in order to satisfy the condition (development time t2<groove portion transit time T<blank time t1, compared to the case in which the duty ratio is 50%. Further, not only the duty ratio, but also, the frequency may be set to make the development time t2 become desirable for satisfying the condition. Moreover, the frequency and duty ratio may be set in combination. The development bias in this embodiment was tested by carrying out Experiments 3-1 and 3-2, which were made different in the number of pulses of the alternating portion, number of blanks, long period frequency, development time t2, and blank time t1, within a range in which the condition (development time t2<groove portion transit time T). Further, both the development bias used in Experiment 3-1 and that in Experiment 3-2 were WBP which was 60% in duty ratio. More concretely, in Experiment 3-1, the frequency of the alternating portion, which is rectangular in waveform, was set to 10 KHz, and blank count was set to four (pulses). Further, the long period frequency was set to 2.5 kHz, and development time t2 was set to 80 μs. Further, the blank time t1 was set to 200 μs. In comparison, in Experiment 3-2, the frequency of the alternating portion, which is rectangular in waveform, was set to 12 kHz, and the blank count was set to 6 (pulses), and the long period frequency was set to 2 kHz. Further, the development time t2 was set to 67 μs, and the blank time t1 was set to 250 μs. That is, the development bias in Experiment 3-2 was increased in frequency to further reduce the development time duration t2. TABLE 3 Freq. of No. Rectang. of Long period Developing Blank Portions Blank Freq. time time t1 Peak Waveform Duty % kHz pulses kHz μ s μ s value Emb. 3-1 WBP 60 10 4 2.5 80 200 Non Emb. 3-2 WBP 60 12 6 2 67 250 Non Next, the results of the experiments are described. As will be evident from Table 3, in both Experiments 3-1 and 3-2, the peak value was zero. That is, there was no peak value attributable to groove pitch. In other words, the development bias in this embodiment made it possible to obtain images which do not suffer from the nonuniformity in density attributable to groove pitch. Changing a development bias in duty ratio to reduce it in development time t2 lengthens the recovery time. However, the recovery time does not contribute to development. Therefore, reducing a development bias in development time t2 by structuring the development bias so that its duty ratio becomes the same as that in Experiments 3-1 and 3-2 can enhance the development bias in its effectiveness for reducing the nonuniformity in image density attributable to groove pitch, as providing a development bias with a blank portion (pulses). As described above, in the case of the developing device 1 in this embodiment, its development bias is structured so that the duty ratio of its alternating portion is set to make the development time t2 become shorter than the recovery time, and therefore, it can further reduce the nonuniformity in image density attributable to groove pitch, compared to the development bias which is simply provided with a blank pulse (blank portion). While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. This application claims priority from Japanese Patent Application No. 159287/2013 filed Jul. 31, 2013, which is hereby incorporated by reference.

A developing apparatus includes a developer carrying sleeve for carrying a developer to a position opposing an image bearing drum. The sleeve is provided with a plurality of groove portions extending in an axial direction of the sleeve, and a developing bias voltage applying device for applying a developing bias voltage to the sleeve. The bias voltage applying device is capable of outputting, as the bias voltage, a voltage of a waveform having a cyclic period including an AC bias portion having an AC component and a DC component superimposed thereto, and a blank portion following the AC bias portion and consisting of a DC component. A width L (m) of the groove, a peripheral speed Vs (m/s) of the sleeve, and a duration t1 (s) of the blank portion in one cyclic period of the bias voltage satisfy L/Vs<t1.

CROSS-REFERENCE TO RELATED APPLICATIONS This invention is related to the technology disclosed in my related U.S. Patent Applications Ser. No. 918,576 filed July 24, 1978, and Ser. No. 092,468 filed Nov. 8, 1979. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a polyphonic digital synthesizer of periodic signals for the production of musical sound. More particularly, it concerns entirely digital synthesizers in which each periodic signal results from a succession of digital samples produced in particular from a wave form sample memory read at variable frequency and then converted into analog form. 2. Description of the Prior Art Such synthesizers have already been described in French patent applications Nos. 7607419 of Mar. 16, 1976, 7720245 of July 1, 1977, 7832727 of Nov. 21, 1978, and in first certificate of addition number 7907339 of Mar. 23, 1979. Each sample is produced from a set of digital data such as instantaneous phase, current amplitude (signal envelope), harmonic or octave row, analog output path, etc., which are stored in a block of memories. Each sample therefore results from the reading of a block of memories. This same block is the source of a complete periodic signal, by virtue of the periodic reading of this block and simultaneous updating of the instantaneous phase datum which it contains. All of the samples of all of the periodic signals are produced sequentially and cyclically in a series which results from connecting the reading of the memory blocks. Given that a complex output sound can be considered as the sum of a certain number of elementary periodic signals, e.g. sinusoidal, and given the polyphonic nature of the synthesizer, there are numerous memory blocks organized into an assembly called the "virtual keyboard." The synthesizer thereby generates a great number of signals automatically using the data inscribed in the "virtual keyboard." To make up a complete musical instrument, such as an electric organ, the synthesizer is connected to keyboards, pedals, buttons, stops, and control means which register the data necessary for the generation of signals in the "virtual keyboard," according to actions taken with the keys, buttons, pedals, and stops, and as a function of time. In a quality musical instrument in particular, the development over time of the amplitude of each sound component must be made with great precision and according to given principles. But this need involves considerable work by the control means of the instrument, as well as great complexity of such means and a high cost for the circuits which compose them. SUMMARY OF THE INVENTION Accordingly, one object of this invention is to provide a novel synthesizer which avoids the above-noted problem by considerably simplifying the work performed by the control means with regard to the control of the development of each sound component (or periodic signal). Another object of the present invention is a new synthesizer in which the amplitude of each sound component is capable of developing automatically over time between an initial running value and a given final value, according to a given principle, and of doing so without intervention of the instrument's control means, at least until the final amplitude value has been reached. According to one characteristic of the invention, the synthesizer comprises: plural generators of rectangular signals of given frequencies; a set of memory blocks containing at least instantaneous phase data, octave or harmonic row data, and amplitude data; control means for reading the memory blocks sequentially and in a given series which is a function of the generator signals; means for producing analog samples of periodic signals from the data read in the blocks; and means for automatically developing, as a function of time, the amplitude of each periodic signal, comprising computation means for periodically replacing the amplitude datum of each block which contains one with a new amplitude datum computed by interpolation between the initial amplitude and a predetermined final amplitude. For example, one or more amplitude clock generators determine the rhythm of computation of the new amplitude values. According to another characteristic of the invention, each block containing a running amplitude datum further contains a final amplitude datum which serves periodically for the computation of the new running amplitude. The development of the amplitudes of the different periodic signals is thus mutually independent. According to the invention, therefore, the amplitude datum in the virtual keyboard block is automatically modified at the rhythm of the amplitude clock (very low frequency) according to an essentially linear or logarithmic interpolation. The logarithmic (or exponential) interpolation, in particular, enables a very gentle and natural development of the amplitude between the initial and final values to be obtained, without the listener sensing a stepwise amplitude development. The amplitude clock is completely independent of the rectangular signal generators which determine the frequencies of the elementary tones. Several amplitude clocks are even desirable so as to make available a great variety of amplitude development speeds. Given that this amplitude development is carried out automatically by the synthesizer, the instrument's control means are now required only to furnish several points of the amplitude envelope curve of the periodic output signals, which simplifies the task of the control means considerably and enables the general qualities of the instrument to be greatly improved. According to a preferred embodiment of the invention, the means used for automatic development of amplitude may be common with other of the synthesizer's computational means, limiting the complexity of the circuits. These means may also be blocked at any time by the instrument's outside control means, thus suspending automatic operation and leaving the possibility of creating special effects to the instrument control means. BRIEF DESCRIPTION OF THE DRAWINGS A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: FIG. 1 is a block diagram of the general structure of a synthesizer according to the invention; FIG. 2 is a detailed circuit diagram of the automatic amplitude development circuits and the control circuits of the invention; FIG. 3 is a graph illustrating an amplitude development curve running from an initial to a final value; FIG. 4 is a graph illustrating a complete curve of the development of the amplitude of a sound component; and FIG. 5 is a flow chart explaining the progress of operations within the synthesizer. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1 thereof, the synthesizer of the invention includes as an essential element "virtual keyboard" 2, which is a set of memory blocks, each containing digital parameters used for generating a sample of a periodic signal. The virtual keyboard consists, for example, of a memory composed of 256 blocks of 7 memories each. The contents of each of the memories of the blocks will be set forth clearly in the following. The blocks are read one by one, sequentially and according to a given series. The contents of the seven memories of each block are read simultaneously and applied to the other circuits of the synthesizer. They occasion the production of a sample and/or the updating of a datum contained in the virtual keyboard (running amplitude, instantaneous phase). The virtual keyboard is therefore the basic element of the synthesizer since it contains both the data necessary for the production of successive samples of elementary signals and address pointers enabling sequential reading of the blocks in a given series. The position of each block in the virtual keyboard is defined by an address. This position may vary. It is decided by the synthesizer's outside control means. The position of each datum in a block is, by contrast, constant, with each memory coupled to one or more specific circuits of the synthesizer. There are therefore two types of blocks in virtual keyboard 2: main blocks and secondary blocks. Each main block contains an instantaneous phase value Ψ which is automatically incremented in substantial synchronization with the signal of a generator designated within the block by a number I. The block also contains a primary pointer PP, i.e. the address of another main block, a secondary pointer PS, i.e. the address of a secondary block, and a block type identification bit T (e.g. T=1 for a main block). Each secondary block contains digital data relating to octave O, wave form and type F, analog output path selection V, running amplitude AC, final amplitude AF, and selection of amplitude clock generator VA. It further contains a bit M for validation or restriction of automatic amplitude development, a secondary pointer PS, i.e. the address of another block (either main or secondary), and a block type identification bit T (T=0 for a secondary block). Memory 10 contains the bit for identification of each type of block (T=1 or 0). Memory 11 contains secondary pointer PS for the two types of blocks. Memory 12 contains either primary pointer PP, where a main block is concerned, or data M, VA and AF where a secondary block is concerned. Memory 13 contains either instantaneous phase Ψ (main block) or running amplitude AC (secondary block). This particular memory enables the circuits for incrementation of phase Ψ and variation of amplitude AC to be combined, these circuits having the same connection to the virtual keyboard. Memory 14 contains either frequency generator number I (main block) or output path number V (secondary block). Memories 15 and 16 contain respectively either the numbers for waveform F or octave O where a secondary block is concerned, or no significant data, in the case of a main block. These positions are of course available for containing data for eventual supplementary operations. The significance of the data delivered by virtual keyboard V thus depends on the type of block read, i.e. on indicator T read in memory 10. The unfolding of operations within the synthesizer is thus directly tied to the reading of the blocks according to a set series, or chain, as described with reference to the following FIG. 5. This unfolding is automatic, but it is nevertheless conditioned by the content of memories 11 and 12 (pointers), and determined by the control means of the instrument (not shown) and by the rectangular signals of a certain number of generators. The control means of the musical instrument (not shown) communicate with the synthesizer through a set of connections called a "bus" 1. The controls of the synthesizer thus amount to read and write operations in the virtual keyboard from bus 1. Selection of the blocks of the virtual keyboard is made by an address register 3, likewise connected to bus 1. This register is, in fact, a buffer register supplied with an address furnished either by the bus or by a selector circuit 4 which receives the two address pointers of the virtual keyboard, primary pointer PP of memory 12 and secondary pointer PS of memory 11. Selection depends on a selection control signal delivered by command logic 6 of the synthesizer. Turnover of the addresses in buffer register 3 occurs at the rhythm of a clock 5 or of a clock or control signal which determines the frequency of recurrence of the block read operations and consequently the frequency of production of samples of the elementary signals. However, the choice and order of production of the samples depends both on the content of the memory blocks, particularly the pointers, and on rectangular signal generators 7 and 8. A set of generators 7 of rectangular signals determines the frequencies of the synthesizer's elementary signals. Set 7 contains at least 12 generators, the frequencies of which are fixed and distributed over a chromatic range. Generally, set 7 contains other generators, e.g. controllable frequency generators, enabling the synthesizer to produce signals of variable frequencies as well as special effects. These generators are connected to control logic 6 which, in keeping with the sequence for reading the blocks of virtual keyboard 2, detects changes in state in the generators and orders the updating of phase data Ψ and the production of analog samples. A set of generators 8 determines the speed of amplitude development of the elementary signals. The frequencies of generators 8 are very low (several hertz to several hundred hertz). These generators are likewise connected to control logic 6, which, again in keeping with the sequence for reading the blocks of the virtual keyboard, detects generator state changes and orders the updating of amplitude data AC. In order to do this, the control logic receives, in addition to signals from generators 7 and 8, block type identification bit T, the current address delivered by register 3, validation bit M, speed VA for selection of one of generators 8, number I for selection of one of generators 7, the least significant bit (Ψ o or A o ) of the current phase Ψ or amplitude datum AC, and a signal "=" indicating the equality AC=AF. Depending on the state of all of these signals, logic 6 delivers an order "≠" for updating the current datum Ψ or AC, an order for selection of a primary or secondary pointer to selector 4, and call signals IT and ADR for the synthesizer's outside control means, through BUS 1. The generation of elementary tones by successive samples is thus done from the above-mentioned control signals (T, ≠) and the date read in the virtual keyboard. Computation circuit 20 performs either the incrementation and memorization of phase Ψ or the updating of current amplitude AC as a function of final amplitude AF. An address computation circuit 21 receives phase and waveform and octave numbers F and O, and delivers an address which is applied to a waveform memory 22. The latter delivers a digital instantaneous amplitude sample (or amplitude variation sample) to a digital-analog converter element 23. The analog sample obtained is multiplied, in circuit 24, by the digital current amplitude datum AC and the result applied to a demultiplexing circuit 25 controlled by path selection datum V. Circuit 25 includes several analog output paths 26 intended to be connected to amplifiers through filtering and amplitude adjustment circuits which are not shown. Circuits 21 to 25 are constructed very simply. Circuits 21 and 22 are read only memories, for example. Circuits 23 and 24 consists, for example, of two digital-analog converters connected in series, the output of one being connected to the reference input of the other. Circuit 25 is a demultiplexing circuit. FIG. 2 represents the details of control logic 6 and of circuit 20 for updating phase and amplitude data. These circuits function from data read in the virtual keyboard, of which only memories 14, 10, 12 and 13 have been represented, along with address register 3 and selector 4. The control logic comprises two multiplex circuits 60 and 61. Circuit 60 receives the rectangular signals delivered by the series of generators 7 (e.g. 16 different frequencies) which determine the frequencies of the periodic output signals. Circuit 61 receives the rectangular signals of the series of generators 8 (e.g. eight frequencies) which determine the speed of development of the amplitude of the periodic signals. Multiplexer 60 therefore outputs the rectangular signal designated by the number I delivered by memory 14 when the block read is a main block (T=1). If not, i.e., if T=0, the output is disconnected (high impedance). Similarly, multiplexer 61 receives datum VA from memory 12 and delivers the signal from the corresponding generator when T=0. In order to do this, datum T (one bit) is applied directly to circuit 60 and, through an inverter gate 64, to circuit 61. The two multiplexer outputs are connected to one input of an exclusive-OR gate 65, the other input of which receives the least significant bits Ψ o (if T=1) or A o (if T=0). The output of gate 65 thus delivers an active ≠ signal if the states of the input signals are different and an inactive signal if they are identical. Each time the "≠" signal is active, it induces an updating of phase datum Ψ or amplitude datum AC (incrementation of the phase or interpolation of the amplitude). This updating must be performed in such a way that the least significant bit of Ψ OR AC is always identical to the state of the generator selected by one of the multiplexers. As long as there is equality, gate 65 will not order an updating. This updating is carried out by circuit 20, which comprises: a first three-input, eight bit adder 35. A first input is connected to memory 13 and thus receives phase Ψ (if T=1) or current amplitude AC (if T=0). A second input permanently receives a logic state 1 (1L). A third input is connected to the output of an AND circuit 34; a second two-input, four bit adder 33. A first input receives the four most significant bits of memory 13 following inversion by an inverter 32. A second input receives the four bits of final amplitude AF. The output of adder 33 is connected to a non-inverting input of AND circuit 34. The other input of AND 34 is inverting and receives signal T; a comparator circuit 31 receiving the contents of memories 12 and 13 delivering an "=" signal as soon as there is identity. For the operation of circuit 20, two cases are possible, according to the value of T: If T=1, the data read in memory 13 is phase Ψ. The binary state of the output of AND 34 is still 0. Consequently, the output of adder 35 delivers Ψ+1. This datum is placed in memory in a register 36 so as to be available (for circuit 21) when the datum read in memory 13 is amplitude AC. Datum Ψ+1 is likewise registered in memory 13 in place of preceding datum Ψ. The order of memorization is given by the "≠" signal delivered by exclusive-OR 65. If T=0, it is datum AC which is delivered by memory 13. The four most significant AC bits at input Y 1 of circuit 32 represent AC/16. Considering similarly that datum Y 2 at the input of adder 33 is AF/16, since memory 12 has only 4 bits, adder 33 delivers: Y.sub.3 =Y.sub.2 -Y.sub.1 =(AF-AC)/16-1 This datum is applied to adder 35 across AND 34, which is open when T=0, with a left shift of one bit, corresponding to a multiplication by two: Y.sub.4 =2Y.sub.3 The output of adder 35 thus delivers: Y.sub.5 =AC+Y.sub.4 +1=AC+2(AF-AC)16-1 This operation performs two functions: a logarithmic interpolation between AC and AF: a reversal of least significant bit A o , since the quantity added, 2(AF-AC)/16-1, is odd. Control logic 6 further comprises an AND circuit 66 performing Tx≠ in order to control selector circuit 4. In fact, as long as ≠ is in state 0, the type of block selected does not change, as long as the states of generators 7 do not change, the blocks read remain main blocks, and no sample is computed. If the reading of a series of secondary blocks is in question, T=0 and the "≠" signal has no effect on selector 4. The series of secondary blocks follows its sequence until a main block appears, as will be explained below. The control logic further comprises an address memory 63 intended to register the address of the block in which there exists the equation AC=AF. In order to do this, the "=" signal delivered by comparator 31 is applied to a logic circuit 62 intended to govern the end of amplitude development in each block. This circuit receives signals T, M (1 bit), "=", and address ADR in memory 63. It delivers memorization control signals to memory 63, multiplexer M blocking signals, and IT interruption signals to the synthesizer's outside control circuits through BUS 1. The IT signal is accompanied by the contents ADR of memory 63. The latter also receives through bus 1 a signal RAZ for clearing its contents. Logic 62 is made up simply of a programmable network (read only memory). The outputs deliver control signals as a function of input signals in accordance with the following truth table, in which the symbol x means "don't care, 1 or 0": ______________________________________M T ADR = Commands______________________________________1 x x x No commandx 1 x x No command0 0 ≠0 x Transmission of IT No memory in 63 Blocking of multiplexer 610 0 =0 0 No IT signal No memorization in 63 Unblocking of multiplexer 610 0 =0 1 Transmission of signal IT Memorization of ADR in 63 Blocking of multiplexer 61______________________________________ FIG. 3 represents the automatic development of the amplitude of a periodic output signal over time t from an initial amplitude to a final amplitude. It shows an increasing signal and a decreasing signal. The amplitude of each signal in fact develops by steps. The points on each curve indicate the new running amplitude AC.sub.(n+1)t calculated from the running amplitude at the preceding point AC nt and final amplitude AF, according to the formula: AC.sub.(n+1)t =AC.sub.nt +(AF-AC.sub.nt)/k with the coefficient k preferably being a power of 2 (k=4 in the case of the Figure). FIG. 4 represents the amplitude envelope curve of a periodic signal. This curve comprises a leading section t 0 -T 1 where the amplitude is rising, a section T 1 -T 5 where the signal undergoes an amplitude tremolo, and a section T 5 -T 6 , etc., involving diminution and extinction of the signal. It should be noted that this complex evolution of amplitude requires only a few amplitude commands (writing new value AF), at instants T1, T2, T3, etc. FIG. 5 is a flow chart explaining the unfolding of the sequence for reading of blocks within the synthesizer. As long as the state of the signals from generators 7 does not change, reading of main blocks proceeds without production of any samples, along loop 100-101-100, etc., which comprises selection of a principal pointer 101, reading of a designated main block (100), and a test of the generator designated by the number I which it contains. If the state of a generator changes (≠), phase Ψ of the main block is incremented (103). The following block, designated by the secondary pointer (102), is first made the object of a test (104). If this block is a main one, there is a return to 101; if it is not a main one, the state of generator 8 designated by datum V A is tested (105). A sample is then computed automatically (107), either using the running amplitude value AC already contained in the block (if there is state change as indicated by the "=" sign) or using a new running amplitude (if "≠") computed (106) according to a logarithmic (or exponential, or linear) interpolation. Then a new block is selected by the secondary pointer (102) and so on. The invention is applied to electronic musical instruments of which it constitutes the principal element. In fact, the production of an instrument such as an electric organ requires other elements surrounding the synthesizer, such as cabinet, keyboards, pedals, electric power supply, low frequency amplification and synthesizer control logic. This control is advantageously composed of a microcomputer, of which the synthesizer according to the invention is a peripheral. This microcomputer, moreover, is very simple and comprises a microprocessor connected to program memories, data memories, and logic circuits making the necessary connections with keyboards, pedals, buttons, stops, etc., as well as with the synthesizer. Several synthesizers may even be coupled to one microcomputer and vice-versa. By automatically carrying out the automatic development of the envelope of each periodic signal up to a final amplitude value, the synthesizer according to the invention frees the microcomputer from the corresponding task. The complexity of the synthesizer is not substantially increased, however, since the phase incrementation and amplitude computation circuits are joint, with the characteristic that each updating operation of phase or amplitude adds an odd quantity to the preceding value, so that the least significant bit may follow the state of a generator. Other equivalent means are obviously foreseeable. It should also be noted that the automatic amplitude development of each periodic signal is independent of that of other signals. Thus, certain periodic signals may be modified from time to time by the control means of the instrument while others may keep the same amplitude, in two possible ways, either by ignoring the IT signal transmitted by control logic 6, or by placing a mask M in memory 12 of the virtual keyboard. This mask M prevents logic 62 from transmitting an IT signal to the microprocessor, but does not prevent the operation of the means (20) for updating the running amplitude. The running amplitude value meanwhile remains constant and equal to AF. Mask M may also be used to block the operation of updating means 20. Obviously, numerous additional 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 practiced otherwise than as specifically described herein.

An entirely digital polyphonic musical synthesizer in which the amplitude of each spectral component may develop either linearly or logarithmically as a function of time, including amplitude computation means which produce, for each period of an amplitude clock signal, a new current amplitude value by linear or logarithmic interpolation between the initial current amplitude and a predetermined final amplitude value. The new current amplitude value is memorized in place of the initial value. When the current amplitude is equal to the final amplitude, a signal is transmitted to the synthesizer control means. The synthesizer enables gentle modulations in amplitude to be obtained and reduces the complexity of the instrument's control means.

BACKGROUND TO THE INVENTION [0001] The present invention relates to mutated nitroreductase enzymes and the DNA encoding them, and their use in the conversion of prodrugs for the treatment of cancer. [0002] One approach to treating cancer is to introduce a gene into the tumour cells that encodes an enzyme capable of converting a prodrug of relatively low toxicity into a potent cytotoxic drug. Systemic administration of the prodrug is then tolerated since it is only converted into the toxic derivative locally, in the tumour, by cells expressing the prodrug-converting enzyme. This approach is known as gene-directed enzyme prodrug therapy (GDEPT), or when the gene is delivered by means of a recombinant viral vector, virus-directed prodrug therapy (VDEPT) (McNeish et al, 1997). [0003] An example of an enzyme/prodrug system is nitroreductase and the aziridinyl prodrug CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide) (Knox et al 1988). Following the observation that the Walker rat carcinoma cell line was particularly sensitive to CB1954, it was shown that this was due to the expression of the rat nitroreductase DT diaphorase. However, since CB 1954 is a poor substrate for the human form of this enzyme, human tumour cells are far less sensitive to CB1954. GDEPT was conceived as a way of introducing a suitable nitroreductase, preferably with greater activity against CB1954, in order to sensitise targeted cells. The Escherichia coli nitroreductase (EC1.6.99.7, alternatively known as the oxygen-insensitive NAD(P)H nitroreductase or dihydropteridine reductase, and often abbreviated to NTR) encoded by the NFSB gene (alternatively known as NFNB, NFSI, or DPRA) has been widely used for this purpose (Reviewed in Grove et al, 1999). The NFSB-encoded nitroreductase (NTR) is a homodimer that binds two flavin mononucleotide (FMN) cofactor molecules. Using NADH or NADPH as an electron donor, and bound FMN as a reduced intermediate, NTR reduces one or other of the two nitro-groups of CB 1954 to give either the highly toxic 4-hydroxylamine derivative or the relatively non-toxic 2-hydroxylamine. Within cells, 5-(aziridin-1-yl)-4-hydroxylamino-2-nitrobenzamide, probably via a further toxic metabolite, becomes very genotoxic (Knox et al, 1991). The exact nature of the lesion caused is unclear, but is unlike that caused by other agents. A particularly high rate of inter-strand cross-linking occurs and the lesions seem to be poorly repaired, with the result that CB 1954 is an exceptionally affective anti-tumour agent (Friedlos et al, 1992). [0004] The structure of the NFSB NTR has been analysed by X-ray crystallography (Parkinson et al 2000, Lovering et al, 2001). Each monomer consists of 217 amino acids forming a four-stranded beta sheet (a fifth parallel strand is contributed by the other subunit) and ten α helices (A-K) and comprises a large hydrophobic core (residues 2-91 and 131-217), a two helix domain (E and F, residues 92-130) that protrudes from the core region, and an extensive dimer interface formed by parts of helices A, B, G, J and K. (NB: the domain assignments are from Lovering et al, and differ slightly from the earlier structure solved by Parkinson et al). Residues in what Parkinson et al designated as Helix G (residues 113-131) have been identified as being in or near the active site and are important in determining substrate specificity. Lovering et al assigns residues 110-131 to helix F and 135-157 to helix G. However, both papers agree that residues in this region form part of the opening to the substrate- and cofactor-binding pocket and that phenylalanine 124 is particularly important. [0005] The NFSB NTR has sequence homology to a number of other enzymes, in particular FRase I, a flavin reductase enzyme from Vibrio fischeri (Zenno et al 1996). By random mutagenesis, Zenno et al generated a number of nfsb mutants that had greatly increased flavin reductase activity. These mutants all had substitutions of phenylalanine 124 (F124), a crucial position in the αG helix. F124 mutants having substitutions with serine, alanine, threonine, leucine, valine, isoleucine, aspartate, glutamine, arginine and histidine were generated, all of which had substantially increased flavin reductase activity. However, with one exception, the nitroreductase activity of these mutants was either broadly similar or substantially reduced, as judged with nitrofurazone and nitrofurantoin as substrates. The histidine mutant (F124H) had approximately double the wild-type activity for these substrates. However, firstly, these disclosures give no information as to what the effects on other substrates, such as CB1954, might be. Secondly, such data as are disclosed suggest that mutations of the F124 position have, at best, an unpredictable effect on nitroreductase activity and, in general, a deleterious effect. [0006] International patent application WO 00/47725 (Minton et al) discloses bacterial nitroreductases that are structurally unrelated to the E.coli NFSB-encoded enzyme and that are derived from Bacillus species. [0007] The aim of GDEPT is to obtain efficient conversion of a prodrug such as CB1954 in target cells in order to kill not only NTR-expressing cells but also bystander tumour cells that may not have been successfully transfected or transduced. It is therefore desirable to have efficient delivery of the NTR-encoding DNA, prodrugs with as high a therapeutic index as possible, and a nitroreductase enzyme that is as efficient as possible in the conversion of CB1954 and other nitro-based prodrugs to toxic DNA cross-linking products. To address the latter, it is desirable to develop modified nitroreductase enzymes, since these would allow more efficient therapy and/or lower systemic doses of the prodrug. Although prodrugs are of relatively low toxicity in comparison with their activated derivatives, it is nevertheless desirable to reduce the chances of adverse effects by minimising the required dose. STATEMENT OF INVENTION [0008] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of the words, for example “comprising” and “comprises”, means “including but not limited to”, and is not intended to (and does not) exclude other moieties, substitutions, modifications, additives, components, integers or steps. [0009] It is to be understood that references to ‘cancer’ and treatment of cancer, equally apply to a range of neoplastic, hyperplastic or other proliferative disorders including, but not limited to: carcinomas, sarcomas, melanomas, lymphomas, leukaemias and other lymphoproliferative or myeloproliferative conditions, and benign hyperplasias, (such as benign prostatic enlargement). [0010] The present invention is based on efforts to produce a nitroreductase with improved activity in the reduction of prodrugs, especially CB1954. The invention provides mutants of the E. coli nitroreductase enzyme (EC1.6.99.7, alternatively known as the oxygen insensitive NAD(P)H nitroreductase or dihydropteridine reductase) encoded by the NFSB gene (alternatively known as NFNB, NFSI, or DPRA) that have significantly greater nitroreductase activity than the wild-type enzyme when assayed with CB1954. [0011] Among these are enzymes with point mutations at position 40 (S40), in particular, serine substitution to alanine (S40A), glycine (S40G) and threonine (S40T); position 41 (T41), in particular, threonine substitutions to asparagine (T41N), glycine (T41G), isoleucine (T41 1), leucine (T41L) and serine (T41S); position 68 (Y68), in particular, tyrosine substitutions to alanine (Y68A), asparagine (Y68N), aspartate (Y68D), cysteine (Y68C), glutamine (Y68Q), glycine (Y68G), histidine (Y68H), serine (Y68S), and tryptophan (Y68W); position 70 (F70), in particular, phenylalanine substitutions to alanine (F70A), cysteine (F70C), glutamine (F70Q), glutamate (F70E), glycine (F70G), isoleucine (F70l), leucine (F70L), proline (F70P), serine (F70S), threonine (F70T) and valine ((F70V); position 71(N71), in particular, asparagine substitutions to aspartate (N71D), glutamine (N71Q) and serine (N71S); position 120 (G120), in particular, glycine substitutions to alanine (G120A), serine (G120S) and threonine (G120T). Of particular interest is a group of mutations centred on position 124. Phenylalanine substitutions to alanine (F124A), asparagine (F124N), cysteine (F124C), glutamine (F124Q), glycine (F124G), histidine (F124H), isoleucine (F124l), leucine (F124L), lysine (F124K), methionine (F124M), serine (F124S), threonine (F124T), tryptophan (F124W), tyrosine (F124Y) and valine (F124V) are all shown to result in mutant enzymes with substantially greater activity with CB 1954 than the wild-type. [0012] In addition to disclosing single mutants, a number of multiply-mutated recombinant NTRs are provided. Double mutants of tyrosine 68 (Y68) and phenylalanine 124 (F124) were found to have greater activity, especially a tyrosine 68 to glycine substitution combined with a phenylalanine 124 to tryptophan substitution (giving mutant Y68G/F124W). Also beneficial is the double mutant comprising an asparagine 71 to serine substitution combined with a phenylalanine 124 to lysine substitution (giving mutant N71S/F124K). Such improved enzymes are especially useful in directed enzyme prodrug therapy. In particular, a polynucleotide comprising a sequence encoding the improved nitroreductase, together with a promoter and such other regulatory elements required to express said encoded nitroreductase, may be included in a vector suitable for gene therapy. Such a vector may be a plasmid vector, whether intended to replicate episomally, to be transiently expressed, or to integrate into the target cell genome. [0013] Among the regulatory elements operably linked to the encoded enzyme may be elements facilitating tissue-specific expression, such as locus control regions (see U.S. Pat. No. 5,736,359, which is incorporated herein by reference, or EP 0 332667) elements facilitating activation of transcription in most or all tissues, such as ubiquitous chromatin opening elements (see WO 00/05393, U.S. application Ser. No. 09/358,082, incorporated herein by reference ). The use of a tissue-specific promoter, enhancer or LCR, or combination thereof, may allow targeted expression of an operably-linked gene, such as one encoding a prodrug-converting enzyme, in cells of a particular tissue type. In some cases, tumour cells may be targeted in a similar way, using promoters that allow expression only in, for example, foetal tissue and certain tumour types. Use of such systems helps to prevent expression of therapeutic genes, such as prodrug-converting enzymes, in healthy tissue and so minimises adverse side-effects. [0014] Alternatively, the vector may be a viral vector, such as adenovirus, adeno-associated virus, herpesvirus, vaccinia, or a retrovirus, including those of the lentivirus group. Such a virus may be modified to alter its natural tropism or to target it to a particular organ, tissue or cell type. In some forms of VDEPT, the specificity of the cell targeting is derived from such manipulation. Alternatively, a targeting moiety such as an antibody, or portion thereof (in which case the procedure is sometimes known as antibody-directed enzyme-prodrug therapy, or ADEPT), or some other specific ligand capable of binding to a cell surface receptor may be used to target either an active enzyme or a polynucleotide encoding such an enzyme to a target cell. [0015] The vector may be administered to the patient systemically (parenterally or enterally), regionally (for instance by perfusion of an isolated limb, or peritoneal infusion), or locally as, for example, a direct intradermal, intramuscular, intraperitoneal, intracranial or intratumoral injection. [0016] After administration of the polynucleotide encoding the improved nitroreductase enzyme, and allowance of a suitable time for expression of the enzyme to occur, a suitable prodrug is administered, either locally (for instance around a tumour), regionally (for instance by perfusion of an isolated limb, or peritoneal infusion) or systemically. In principle, any prodrug that is capable of being activated by means of reduction and, in particular reduction of nitro-groups, may be suitable. Such compounds include nitrobenzamides, in particular nitro- and dinitrobenzamide aziridines and mustards. Particularly suitable are the dinitrobenzamide aziridine 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB1954) and the dinitrobenzamide mustard 5-[N,N-bis (2-chloroethyl)amino]-2,4-dinitrobenzamide (SN23862), and functional and structural analogues thereof. [0017] Accordingly, the current invention provides a recombinant mutant nitroreductase, characterised in that said nitroreductase has increased nitroreductase activity as compared to the wild-type enzyme. Preferably, said nitroreductase has an increased nitroreductase activity for prodrugs, more preferably for nitrobenzamide and dinitrobenzamide aziridine and mustard prodrugs and most preferably for the dinitrobenzamide aziridine prodrug CB1954. [0018] In one aspect of the invention, the recombinant mutant nitroreductase is encoded by a mutated equivalent of the wild-type E. coli NFSB gene. Alternatively, the recombinant mutant nitroreductase is encoded by structurally homologous gene from another genus such as from Salmonella or Enterobacter, or from another species, such as the Salmonella typhimurium NFNB gene, or the Enterobacter cloacae NFNB gene. [0019] In all cases is it is understood that the beneficial mutation disclosed is not exclusive of further mutations at adjacent or more distant sites in the amino acid sequence. [0020] Accordingly is provided a recombinant mutant nitroreductase encoded by a mutated equivalent of the E.coli NFSB gene, characterised in that it comprises a substitution of one or more amino acids selected from a group consisting of serine 40, threonine 41, tyrosine 68, phenylalanine 70, asparagine 71, glycine 120, and phenylalanine 124. [0021] A first preferred embodiment is a nitroreductase encoded by a mutated equivalent of the E.coli NFSB gene, characterised in that it comprises a substitution of serine 40 with an amino acid selected from a group consisting of alanine, glycine and threonine. [0022] Alternatively, the nitroreductase is a protein selected from the group consisting of: i. a recombinant E coli NFSB nitroreductase mutant corresponding to the wild type sequence of FIG. 9 (SEQ ID NO:1), characterised in that serine 40 is substituted by an amino acid selected from the group consisting of alanine, glycine and threonine; ii. variants of (i) characterised in that they have substitutions, insertions or deletions at residues other than serine 40 and having nitroreductase activity greater than that of the wild-type protein. [0025] A second preferred embodiment is a nitroreductase encoded by a mutated equivalent of the E.coli NFSB gene, characterised in that it comprises a substitution of threonine 41 with an amino acid selected from a group consisting of asparagine, glycine, isoleucine, leucine and serine. [0026] Alternatively, the nitroreductase is a protein selected from the group consisting of: i. a recombinant E coli NFSB nitroreductase mutant corresponding to the wild type sequence of FIG. 9 (SEQ ID NO:1), characterised in that threonine 41 is substituted by an amino acid selected from the group consisting of asparagine, glycine, isoleucine, leucine and serine; ii. variants of (i) characterised in that they have substitutions, insertions or deletions at residues other than threonine 41 and having nitroreductase activity greater than that of the wild-type protein. [0029] A third preferred embodiment is a nitroreductase encoded by a mutated equivalent of the E.coli NFSB gene, characterised in that it comprises a substitution of tyrosine 68 with an amino acid selected from a group consisting of alanine, asparagine, aspartate, cysteine, glutamine, glycine, histidine, serine, and tryptophan. [0030] Alternatively, the nitroreductase is a protein selected from the group consisting of: i. a recombinant E coli NFSB nitroreductase mutant corresponding to the wild type sequence of FIG. 9 (SEQ ID NO:1), characterised in that tyrosine 68 is substituted by an amino acid selected from the group consisting of alanine, asparagine, aspartate, cysteine, glutamine, glycine, histidine, serine, and tryptophan; ii. variants of (i) characterised in that they have substitutions, insertions or deletions at residues other than tyrosine 68 and having nitroreductase activity greater than that of the wild-type protein. [0033] Preferably, said tyrosine 68 mutant variants described in (ii) above are double mutants also comprising mutations at phenylalanine 124. More preferably, said tyrosine 68 and phenylalanine 124 double mutants comprise a first substitution of tyrosine 68 to glycine (Y68G) and a second substitution of phenylalanine 124 by an amino acid selected from either one of glutamine (F124Q) or tryptophan (F124W). [0034] A fourth preferred embodiment is a nitroreductase encoded by a mutated equivalent of the E.coli NFSB gene, characterised in that it comprises a substitution of phenylalanine 70 with an amino acid selected from a group consisting of alanine, cysteine, glutamine, glutamate, glycine, isoleucine, leucine, proline, serine, threonine and valine. [0035] Alternatively, the nitroreductase is a protein selected from the group consisting of: i. a recombinant E coli NFSB nitroreductase mutant corresponding to the wild type sequence of FIG. 9 (SEQ ID NO:1), characterised in that phenylalanine 70 is substituted by an amino acid selected from the group consisting of alanine, cysteine, glutamine, glutamate, glycine, isoleucine, leucine, proline, serine, threonine and valine; ii. variants of (i) characterised in that they have substitutions, insertions or deletions at residues other than phenylalanine 70 and having nitroreductase activity greater than that of the wild-type protein. [0038] A fifth preferred embodiment is a nitroreductase encoded by a mutated equivalent of the E.coli NFSB gene, characterised in that it comprises a substitution of asparagine 71 with an amino acid selected from a group consisting of aspartate, glutamine and serine. [0039] Alternatively, the nitroreductase is a protein selected from the group consisting of: i. a recombinant E coli NFSB nitroreductase mutant corresponding to the wild type sequence of FIG. 9 (SEQ ID NO:1), characterised in that asparagine 71 is substituted by an amino acid selected from the group consisting of aspartate, glutamine and serine; ii. variants of (i) characterised in that they have substitutions, insertions or deletions at residues other than asparagine 71 and having nitroreductase activity greater than that of the wild-type protein. [0042] Preferably, said asparagine 71 mutant variants described in (ii) above are double mutants also comprising mutations at phenylalanine 124. More preferably, said asparagine 71 and phenylalanine 124 double mutants comprise a first substitution of asparagine 71 to serine (N71S) and a second substitution of phenylalanine 124 to lysine (F124K). [0043] A sixth preferred embodiment is a nitroreductase encoded by a mutated equivalent of the E.coli NFSB gene, characterised in that it comprises a substitution of glycine 120 with an amino acid selected from a group consisting of alanine, serine and threonine. [0044] Alternatively, the nitroreductase is a protein selected from the group consisting of: i. a recombinant E coli NFSB nitroreductase mutant corresponding to the wild type sequence of FIG. 9 (SEQ ID NO:1), characterised in that glycine 120 is substituted by an amino acid selected from the group consisting of alanine, serine and threonine; ii. variants of (i) characterised in that they have substitutions, insertions or deletions at residues other than glycine 120 and having nitroreductase activity greater than that of the wild-type protein. [0047] A seventh preferred embodiment is a nitroreductase encoded by a mutated equivalent of the E.coli NfsB gene, characterised in that it comprises a substitution of phenylalanine 124 with an amino acid selected from a group consisting of asparagine, cysteine, glycine, lysine, methionine, tryptophan and tyrosine. [0048] Alternatively, the nitroreductase is a protein selected from the group consisting of: i. a recombinant E coli NFSB nitroreductase mutant corresponding to the wild type sequence of FIG. 9 (SEQ ID NO:1), characterised in that phenylalanine 124 is substituted by an amino acid selected from the group consisting of asparagine, cysteine, glycine, lysine, methionine, tryptophan and tyrosine; ii. variants of (i) characterised in that they have substitutions, insertions or deletions at residues other than phenylalanine 124 and having nitroreductase activity greater than that of the wild-type protein. [0051] In another aspect of the invention, a polynucleotide encoding any of the above mutated nitroreductases is provided. [0052] The invention also provides a recombinant mutated nitroreductase as disclosed above, or a polynucleotide encoding it, for use as a medicament. Preferably, that medicament is of use in the treatment of cancer, more preferably by the conversion of a prodrug to an active cytotoxic compound, and further preferably the prodrug to be converted to an active cytotoxic compound is a nitrobenzamide aziridine or mustard, and most preferably it is CB1954. [0053] A eighth preferred embodiment of the invention is a recombinant mutant nitroreductase encoded by a mutated E.coli NfsB gene, characterised in that it comprises the substitution of phenylalanine 124 with an amino acid selected from the group consisting of alanine, glutamine, histidine, isoleucine, leucine, serine, threonine or valine, for use as a medicament. Preferably, that medicament is of use in the treatment of cancer, or other proliferative disorder, more preferably by the conversion of a prodrug to an active cytotoxic compound, and further preferably the prodrug to be converted to an active cytotoxic compound is a nitrobenzamide aziridine or mustard, and most preferably it is CB1954. [0054] Alternatively the nitroreductase is a protein selected from the group consisting of: i. A recombinant E coli NfsB nitroreductase mutant corresponding to the wild type sequence of FIG. 6 , characterised in that phenylalanine 124 is substituted by an amino acid selected from the group consisting of alanine, glutamine, histidine, isoleucine, leucine, serine, threonine or valine; ii. Variants of (i) characterised in that they have substitutions, insertions or deletions at residues other than phenylalanine 124 and having nitroreductase activity greater than that of the wild-type protein. for use as a medicament. Preferably, that medicament is of use in the treatment of cancer, more preferably by the conversion of a prodrug to an active cytotoxic compound, and further preferably the prodrug to be converted to an active cytotoxic compound is a nitrobenzamide aziridine or mustard, and most preferably it is CB1954. [0058] In another aspect, the use of any of the above-disclosed recombinant mutant nitroreductases and polynucleotides encoding them for the manufacture of a medicament is disclosed. Preferably, said medicament is for enzyme prodrug therapy. Said medicament may take the form of naked DNA, a DNA-peptide, DNA-lipid or DNA-polymer conjugate or complex, or viral vector, comprising a polynucleotide encoding a recombinant mutant nitroreductase operably linked to a promoter with or without further elements such as enhancers and LCRs so arranged as to permit efficient tissue-specific expression of said nitroreductase in the appropriate cells following administration and transfection of said cells. Alternatively, said medicament may comprise such a DNA-peptide, DNA-lipid or DNA-polymer conjugate or complex, or viral vector comprising a targeting moiety, such as an antibody or fragment thereof, or a peptide or carbohydrate ligand capable of binding specifically to a suitable cell surface receptor or other structure so as to allow efficient targeting to appropriate cell types. [0059] Also provided is a process to manufacture a medicament characterised in the use of any of the above-disclosed recombinant mutant nitroreductases and polynucleotides encoding them. [0060] In another embodiment is provided a pharmaceutical composition comprising any one of the above-disclosed recombinant mutant nitroreductases or polynucleotides encoding them, or viral or non-viral vectors comprising such polynucleotides in an acceptable diluent or excipient. [0061] In another aspect of the invention are provided vectors comprising isolated polynucleotides encoding one or more of the above-disclosed recombinant mutant nitroreductases. As detailed below, these vectors may be replicating or non-replicating, episomal or integrating, designed for use in prokaryotic or eukaryotic cells. They may be expression vectors providing ubiquitous or tissue-specific expression of the encoded nitroreductase, which may be operably-linked to suitable promoters and other elements required for appropriate expression, such as LCRs or UCOEs. In a more preferred embodiment, said vector provides tissue-specific expression of nitroreductase. Further preferably, the nitroreductase is preferentially expressed in tumours. Most preferably, the vector comprises a TCF-responsive element operably linked to a polynucleotide encoding nitroreductase. [0062] In a further preferred embodiment, said vector is a virus, and most preferably it is an adenovirus. The use of adenovirus vectors comprising a TCF-responsive tumour-selective promoter element operably linked to a nitroreductase gene is described in International application number PCT/GB01/00856, the whole of which is incorporated herein by reference. A copy of GB 01/00856 is filed with this application and its content is included in the present application but the copy is not included in the published specification of this application. [0063] The vector may be any vector capable of transferring DNA to a cell. Preferably, the vector is an integrating vector or an episomal vector. [0064] Preferred integrating vectors include recombinant retroviral vectors. A recombinant retroviral vector will include DNA of at least a portion of a retroviral genome which portion is capable of infecting the target cells. The term “infection” is used to mean the process by which a virus transfers genetic material to its host or target cell. Preferably, the retrovirus used in the construction of a vector of the invention is also rendered replication-defective to remove the effect of viral replication of the target cells. In such cases, the replication-defective viral genome can be packaged by a helper virus in accordance with conventional techniques. Generally, any retrovirus meeting the above criteria of infectiousness and capability of functional gene transfer can be employed in the practice of the invention. [0065] Suitable retroviral vectors include but are not limited to pLJ, pZip, pWe and pEM, well known to those of skill in the art. Suitable packaging virus lines for replication-defective retroviruses include, for example, ΨCrip, ΨCre, Ψ2 and ΨAm. [0066] Other vectors useful in the present invention include adenovirus, adeno-associated virus, SV40 virus, vaccinia virus, HSV and poxvirus vectors. A preferred vector is the adenovirus. Adenovirus vectors are well known to those skilled in the art and have been used to deliver genes to numerous cell types, including airway epithelium, skeletal muscle, liver, brain and skin (Hitt, M M, Addison C L and Graham, F L (1997) Human adenovirus vectors for gene transfer into mammalian cells. Advances in Pharmacology, 40: 137-206; and Anderson W F (1998) Human gene therapy. Nature, 392: (6679 Suppl): 25-30). [0067] A further preferred vector is the adeno-associated (AAV) vector. AAV vectors are well known to those skilled in the art and have been used to stably transduce human T-lymphocytes, fibroblasts, nasal polyp, skeletal muscle, brain, erythroid and haematopoietic stem cells for gene therapy applications (Philip et al., 1994, Mol. Cell. Biol., 14, 2411-2418; Russell et al., 1994, PNAS USA, 91, 8915-8919; Flotte et al., 1993, PNAS USA, 90, 10613-10617; Walsh et al., 1994, PNAS USA, 89, 7257-7261; Miller et al., 1994, PNAS USA, 91, 10183-10187; Emerson, 1996, Blood, 87, 3082-3088). International Patent Application WO 91/18088 describes specific AAV based vectors. [0068] Preferred episomal vectors include transient non-replicating episomal vectors and self-replicating episomal vectors with functions derived from viral origins of replication such as those from EBV, human papovavirus (BK) and BPV-1. Such integrating and episomal vectors are well known to those skilled in the art and are fully described in the body of literature well known to those skilled in the art. In particular, suitable episomal vectors are described in WO98/07876. [0069] Mammalian artificial chromosomes can also be used as vectors in the present invention. The use of mammalian artificial chromosomes is discussed by Calos (1996, TIG, 12, 463-466). [0070] In a preferred embodiment, the vector of the present invention is a plasmid. The plasmid may be a non-replicating, non-integrating plasmid. [0071] The term “plasmid” as used herein refers to any nucleic acid encoding an expressible gene and includes linear or circular nucleic acids and double or single stranded nucleic acids. The nucleic acid can be DNA or RNA and may comprise modified nucleotides or ribonucleotides, and may be chemically modified by such means as methylation or the inclusion of protecting groups or cap- or tail structures. [0072] A non-replicating, non-integrating plasmid is a nucleic acid which when transfected into a host cell does not replicate and does not specifically integrate into the host cell's genome (i.e. does not integrate at high frequencies and does not integrate at specific sites). [0073] Replicating plasmids can be identified using standard assays including the standard replication assay of Ustav et al., EMBO J., 10, 449-457, 1991. [0074] The present invention also provides a host cell transfected with the vector of the present invention. The host cell may be any mammalian cell. Preferably the host cell is a rodent or mammalian cell. Most preferably it is a human cell. [0075] Numerous techniques are known and are useful according to the invention for delivering the vectors described herein to cells, including the use of nucleic acid condensing agents, electroporation, complexing with asbestos, polybrene, DEAE cellulose, Dextran, liposomes, cationic liposomes, lipopolyamines, polyornithine, particle bombardment and direct microinjection (reviewed by Kucherlapati and Skoultchi, Crit. Rev. Biochem. 16:349-379 (1984); Keown et al., Methods Enzymol. 185:527 (1990)). [0076] A vector of the invention may be delivered to a host cell non-specifically or specifically (i.e., to a designated subset of host cells) via a viral or non-viral means of delivery. Preferred delivery methods of viral origin include viral particle-producing packaging cell lines as transfection recipients for the vector of the present invention into which viral packaging signals have been engineered, such as those of adenovirus, herpes viruses and papovaviruses. Preferred non-viral based gene delivery means and methods may also be used in the invention and include direct naked nucleic acid injection, nucleic acid condensing peptides and non-peptides, cationic liposomes and encapsulation in liposomes. [0077] The direct delivery of vector into tissue has been described and some short-term gene expression has been achieved. Direct delivery of vector into muscle (Wolff et al., Science, 247, 1465-1468, 1990) thyroid (Sykes et al., Human Gene Ther., 5, 837-844, 1994) melanoma (Vile et al., Cancer Res., 53, 962-967, 1993), skin (Hengge et al., Nature Genet, 10, 161-166, 1995), liver (Hickman et al., Human Gene Therapy, 5, 1477-1483, 1994) and after exposure of airway epithelium (Meyer et al., Gene Therapy, 2, 450-460, 1995) is clearly described in the prior art. [0078] Various peptides derived from the amino acid sequences of viral envelope proteins have been used in gene transfer when co-administered with polylysine DNA complexes (Plank et al., J. Biol. Chem. 269:12918-12924 (1994));. Trubetskoy et al., Bioconjugate Chem. 3:323-327 (1992); WO 91/17773; WO 92/19287; and Mack et al., Am. J. Med. Sci. 307:138-143 (1994)) suggest that co-condensation of polylysine conjugates with cationic lipids can lead to improvement in gene transfer efficiency. International Patent Application WO 95/02698 discloses the use of viral components to attempt to increase the efficiency of cationic lipid gene transfer. [0079] Nucleic acid condensing agents useful in the invention include spermine, spermine derivatives, histones, cationic peptides, cationic non-peptides such as polyethyleneimine (PEI) and polylysine. ‘Spermine derivatives’ refers to analogues and derivatives of spermine and include compounds as set forth in International Patent Application WO 93/18759 (published Sep. 30, 1993). [0080] Disulphide bonds have been used to link the peptidic components of a delivery vehicle (Cotten et al., Meth. Enzymol. 217:618-644 (1992)); see also, Trubetskoy et al. (supra). [0081] Delivery vehicles for delivery of DNA constructs to cells are known in the art and include DNA/poly-cation complexes which are specific for a cell surface receptor, as described in, for example, Wu and Wu, J. Biol. Chem. 263:14621 (1988); Wilson et al., J. Biol. Chem. 267:963-967 (1992); and U.S. Pat. No. 5,166,320). [0082] Delivery of a vector according to the invention is contemplated using nucleic acid condensing peptides. Nucleic acid condensing peptides, which are particularly useful for condensing the vector and delivering the vector to a cell, are described in International Patent Application WO 96/41606. Functional groups may be bound to peptides useful for delivery of a vector according to the invention, as described in WO 96/41606. These functional groups may include a ligand that targets a specific cell-type such as a monoclonal antibody, insulin, transferrin, asialoglycoprotein, or a sugar. The ligand thus may target cells in a non-specific manner or in a specific manner that is restricted with respect to cell type. [0083] The functional groups also may comprise a lipid, such as palmitoyl, oleyl, or stearoyl; a neutral hydrophilic polymer such as polyethylene glycol (PEG), or polyvinylpyrrolidine (PVP); a fusogenic peptide such as the HA peptide of influenza virus; or a recombinase or an integrase. The functional group also may comprise an intracellular trafficking protein such as a nuclear localisation sequence (NLS), an endosome escape signal such as a membrane disruptive peptide, or a signal directing a protein directly to the cytoplasm. [0084] Also provided is a host cell comprising a polynucleotide encoding a recombinant mutant nitroreductase of the invention, or a host cell comprising a vector comprising such a polynucleotide. Such a host cell may be a bacterial cell used to grow, manufacture, screen and test said vector, or a eukaryotic cell, preferably a mammalian cell and most preferably a human cell, in which the encoded nitroreductase is expressed. [0085] In another aspect of the invention is provided an isolated polynucleotide encoding a nitroreductase of the invention, or a vector comprising such a polynucleotide, or a host cell comprising either said polynucleotide or vector for use in gene therapy. Preferably such gene therapy is of use in treating cancer. [0086] In another aspect of the invention, the use of a recombinant nitroreductase to aid in the design of, or screening for improved prodrugs is provided. Such a use comprises contacting said nitroreductase with candidate prodrugs and chemically measuring the kinetics of conversion to a reduced product. Alternatively, an in vitro assay may be used where the ability of a disclosed recombinant mutant nitroreductase to convert candidate prodrugs to cytotoxic products is assayed by the inhibition of growth of bacterial host cells in the presence of various concentrations said prodrugs, or by the killing of eukaryotic cells cultured in the presence of various concentrations of said prodrugs. This may be further examined by an in vivo assay of, for example, tumour killing in an experimental animals by administration of a polynucleotide encoding the recombinant mutant nitroreductase, allowing a suitable time for expression to occur, and then administration of various doses of candidate prodrugs. Comparison of the results using various mutants as well as wild-type nitroreductase allows identification of optimal combinations of mutant nitroreductases and novel prodrugs that provide improved efficiency and therapeutic index. [0087] Also provided is a method of treating cancer in a mammalian subject, comprising administering any of the isolated polynucleotides or vectors described above, allowing a suitable time for expression of the encoded nitroreductase to occur, and administering a prodrug capable of being activated by said expressed nitroreductase. DETAILED DESCRIPTION OF THE INVENTION [0088] The invention is described through Examples with reference to the accompanying Tables and Figures, wherein: [0089] FIG. 1 illustrates the method of site-directed mutagenesis used to generate NTR mutants using PCR; [0090] FIG. 2 shows the construction of the phage (λNM1151Kan R ptac-NTR) used to express the mutant NTRs in lysogenised E. coli cells; [0091] FIG. 3 shows an example of screening mutant NTR-expressing lysogens through growth on increasing concentrations of CB1954. More efficient NTRs lead to greater genotoxicity and so less growth; [0092] FIG. 4 shows the results of the first round of screening of mutant clones by the method illustrated in FIG. 3 ; [0093] FIG. 5 shows an analysis of the number of mutants generated and whether NTR activity was increased or decreased (wild-type enzyme scores 4) by mutation of key amino acids near the active site of NTR; [0094] FIG. 6 summarises the enzyme activity scores for mutants showing increased activity as compared with wild-type NTR, with FIG. 6 a showing the results for S40, T41, Y68, F70, N71, and G120 mutants, while FIG. 6 b shows the results for F124 mutants; [0095] FIG. 7 shows an example of survival curves obtained for a number of mutant clones with percentage survival plotted against CB1954 concentration to enable an IC50 value to be calculated; [0096] FIG. 8 represents the IC50 data generated by such experiments compared to the wild-type enzyme; [0097] FIG. 9 shows the amino acid sequence (SEQ ID NO:1) of wild-type NTR—the protein encoded by the E coli NfsB gene. The key mutation sites at S40, T41, Y68, F70, N71, G120, and F124 are underlined and in bold. [0098] FIG. 10 shows results of experiments using three different recombinant adenovirus vectors to express wild type (A), F124N (B) or double mutant F124N/N71S (C) NTRs in mammalian cell, resulting in sensitisation to and killing by CB1954. The % cells surviving at a range of MOIs and CB1954 concentrations are shown [0099] FIG. 11 shows the levels of expression of the wild type, and F124N and F124N/N71S NTR mutants by western blotting (A), with a Coomassie stained loading control (B). [0100] FIG. 12 shows enzyme kinetic data (k cat , K m , and k cat /K m ratio) for wild type, F124K, N71S and F124N/N71S mutants. EXAMPLE 1 Generation of NTR Mutants with Increased CB 1954 Converting Activity [heading-0101] Methods [heading-0102] Mutagenesis [0103] Mutations were introduced into the NTR sequence at various positions by PCR (see FIG. 1 ) using plasmid pJG12B1 as a template. This is a pUC19-derived plasmid containing the E.coli DH5α NTR within Sfi I cloning sites downstream of the tac promoter. [0104] Referring to Table 1, for mutagenesis at position 40, primer 2 was JG126B (SEQ ID NO:6) and primer 3 was JG126A (SEQ ID NO:5); at position 41 primer 2 was JG126C (SEQ ID NO:7) and primer 3 was JG126A(SEQ ID NO:5); at position 68 primer 2 was JG127B (SEQ ID NO:9) and primer 3 was JG127A(SEQ ID NO:8); at position 71 primer 2 was JG127C (SEQ ID NO:10) and primer 3 was JG127A(SEQ ID NO:8); at position 120, primer 2 was JG128B (SEQ ID NO:12) and primer 3 was JG128A(SEQ ID NO:11); at position 124 primer 2 was JG128C (SEQ ID NO:13) and primer 3 was JG128A (SEQ ID NO:11). Primer 1 was the 5′ primer for JG14A (SEQ ID NO:2) and the 3′ primer, primer 4, was an M13 reverse sequencing primer, PS1107rev (SEQ ID NO:3) (Table 1). [0105] After denaturation at 94° for 5 min, PCR was for 25 cycles of 94°/45s; 55°/50s; 72°/90s followed by 72°/7 min. Pfu DNA polymerase was used according to the manufacturers recommendations (Stratagene ™) to minimise additional mutations. The products of PCR using primers 1 with 2, and 3 with 4, were gel purified to remove excess primers and 5 ng of each was used as a template for PCR with primers 1 and 2 to restore a full length NTR gene. TABLE 1 NTR Mutagenesis PCR Primers SEQ ID NO Primer Sequence 5′ to 3′  2 JG14A GACAATTAATCATCGGCTCG  3 PS1107Rev GCGGATAACAATTTCACACAGGA  4 JG2B CAGAGCATTAGCGCAAGGTG  5 JG126A CCCAGCCGTGGCATTTTATTGTTG  6 JG126B CAACAATAAAATGCCACGGCTGGGAGTTGGTNN NGGATGGGCTGTATTGC  7 JG126C CAACAATAAAATGCCACGGCTGGGAGTTNNNGC TGGATGGGCTGTATTGC  8 JG127A GAGCGTAAAATGCTTGATGCCTCG  9 JG127B CGAGGCATCAAGCATTTTACGCTCGTTGAACAC NNNATTACCGGCAGCGG 10 JG127C CGAGGCATCAAGCATTTTACGCTCNNNGAACAC GTAATTACCGGC 11 JG128A GCTGATATGCACCGTAAAGATCTGC 12 JG128B GCAGATCTTTACGGTGCATATCAGCGAAGAACT TGCGNNNTTTATCGTTCG 14 JG128C GCAGATCTTTACGGTGCATATCAGCNNNGAACT TGCG 15 JG127D CGAGGCATCAAGCATTTTACGCTCGTTNNNCAC GTAATTACCGGC [0106] λJG3J1 was produced from λNM1141 ( FIG. 2 ) by cloning a kanamycin resistance gene from pACYC177 into an Eco RI site and the ptac promoter from pPS1133L10 (ultimately derived from pDR540 [Pharmacia] into a Hind III site. The final PCR products were digested with SfiI and the major central fragment inserted between two matching Sfi I sites within the Hind III fragment, downstream of the tac promoter. [0107] The ligation mix was packaged (Stratagene) into lambda bacteriophage particles that were used to infect UT5600 cells (NTR − ). As a control wild type NTR was also cloned into this vector (JG16C2). Kanamycin resistant lysogens were selected on agar plates (30 ug/ul kanamycin) then individually grown overnight in a well of a 96-well plate in LB+Kanamycin. The clones were replica plated on to a series of plates containing Tris-buffered (50 mM, pH 7.5) LB agar with kanamycin, IPTG (0.1 mM) and CB1954 at a concentration of 0, 25, 35, 50, 100, 200, 300 or 400 μM (see FIG. 3 ). The plates were scored as shown in Table 2 and the results shown in FIGS. 4 and 5 . TABLE 2 Score Criteria 0 Good growth on all concentrations of CB 1954 = vector 1 Good growth on 100 and 200, faint on 300, ring of growth on 400 μM 2 Good growth on 100 and 200, ring growth on 300, none or very faint on 400 μM 3 Good growth on 100, faint to good on 200, none or very faint on 300 and 400 μM 4 Good growth on 100 μM, none to ring growth on 200 μM = wild type 5 Good growth on 50 μM, ring on 100 μM, none on 200, 300 or 400 μM 6 Faint growth on 50 μM, ring on 100 μM 7 Good growth on 50 μM, none on 100 μM 8 Ring growth on 50 μM, none on 100 μM 9 None or very faint growth on 50 μM, none on 100 μM 10 None or ring growth on 35 μM [0108] The DNA from clones with a score >4 was amplified by PCR using primers JG14A and JG2B (Table 1) and sequenced to determine the mutation present (ABI Prism Big Dye Terminator kit). An example of data from the first screening is shown in FIG. 4 and the results are summarised in FIG. 5 . Promising clones were selected for analysis of their IC50s and the results are summarised in Table 3 below. [heading-0109] Combining Mutations [0110] To generate NTR clones containing two gain-of-function mutations the PCR method shown in FIG. 1 was used as for the first round of mutagenesis. To generate a N71S F124K mutant, primer 1 was JG14A (SEQ ID NO:2) and primer 2 was PS1013A (SEQ ID NO:14) (Table 1) using 1 μl phage λ JG131H481 stock as a template. Primer 3 was JG127A (SEQ ID NO:8) and primer 4 was JG2B (SEQ ID NO:4) using λ JG131I399 as a template. The resulting products were then used as templates for primers JG14A (SEQ ID NO:2) and JG2B (SEQ ID NO:4) to generate the double-mutated NTR sequence for cloning as a SfiI fragment into λJG3J1 to give λJG139CB1. Similarly, to construct a Y658G F124Q double mutant, primers JG14A (SEQ ID NO:2) and PS1013A (SEQ ID NO:14) were used to amplify λJG131C19, and primers JG127A (SEQ ID NO:8) and JG2B (SEQ ID NO:4) were used to amplify λJG131I83 followed by PCR amplification of the products with primers JG14A (SEQ ID NO:2) and JG2B (SEQ ID NO:4) to give λJG139DC1. A Y68G F124W double mutant was constructed by amplifying λJG131C194 with primers JG14A (SEQ ID NO:2) and PS1013A (SEQ ID NO:14) and amplifying λJG131I505 with primers JG127A (SEQ ID NO:8) and JG2B (SEQ ID NO:4) followed by PCR using the products as templates for amplification with primers JG2B (SEQ ID NO:4) and JG14A (SEQ ID NO:2) to give λJG139EC12. [heading-0111] Survival Curve Data [0112] To quantify the improvement in NTR activity in the clones in a less subjective way, a few clones were selected for further study by determining their survival curves. The lysogens were grown overnight in LB +kanamycin and diluted to approximately 1 cell per μl based on the OD. In duplicate, 100 μl diluted cells were plated into Tris-buffered LB plates containing kanamycin, IPTG and 0-400 μM CB1954. After 36h growth the number of colonies on each plate were counted and expressed as a percentage of the number present on the plates with no CB1954. Survival curves showing % survival versus concentration of CB 1954 were plotted (see examples in FIG. 7 ) and the IC50 determined as the concentration of CB 1954 which kills gives a 50% reduction in colony number (Table 3 and FIG. 8 ). A few clones containing mutations resulting in an enhanced sensitivity to CB 1954 were selected for further study. [heading-0113] Results [heading-0114] Enzyme Activity Assays [0115] The first screening showed that clones showing increased sensitivity to CB 1954 over the baseline level of the wild-type had mutations clustering at a limited number of positions, notably 40, 41, 68, 70, 71, 120 and 124, as shown in FIG. 4 . Of these, substitution of Phe124 was the commonest site for gain-of-function mutants. FIG. 5 summarises the average scores for the gain-of-function mutants identified. The highest activity mutants were all at position 124. FIG. 6 analyses the change in activity, both up and down, related to the site of mutation. Loss-of-function mutations were commonest at positions 68, 70, 71 ,and 120, although some a few significantly improved clones were also seen, particularly at positions 70 and 71. At position 124, gain-of-function mutants were more common. [heading-0116] IC50 Assays [0117] FIG. 7 shows an example of a survival against CB 1954 concentration plot and the data are summarised in Table 3 and FIG. 8 . The data are broadly consistent with the enzyme activity results, with a number of mutant scoring highly in both assays. On the basis of these results, a number of clones were selected for further study and identified as offering substantial benefits over the wild-type enzyme for applications such as GDEPT. Amongst these were T41L, Y68G, N71S, F124A, F124G, F124N, F124C, F124H, F124L, F124K, F124M, F124S, F124Q, F124T, F124V and F124W. In addition, mutations giving a more modest improvement, but at a less common site (implying perhaps a different mode of action), such as those at S40 and F70 were highlighted. [heading-0118] Double Mutants [0119] Particularly striking was the activity of the double mutant N71S/F124K, with Y68G/F124W also having a significant gain of function over the wild-type. N71S/F124K shows increased enzyme activity as measured by reduced IC50 compared to either mutation alone. This shows that the mutations identified in the first round of screening can have an additive effect. However, the Y68G/F124Q mutant has decreased enzyme activity compared to either mutation alone with activity similar to that of the wild type enzyme, suggesting that combining two single gain-of-function mutations can also cancel each other out resulting in only wild-type levels of enzyme activity. A third double mutant, Y68G/F124W had an IC50 equivalent to that of the better single mutation alone thus demonstrating that combining mutations may also have a neutral effect. TABLE 3 Mutation Clone Score IC50 μM CB1954 Wild type 4 118 S40A K263 5-7 100 S40A K327 5-7 84 S40G K264 5 90 S40T K350 5 102 T41G L229 5-7 120 T41L L233 5-7 38 Y68C C88 5 105 Y68S C103 5-7 96 Y68A C146 5-7 81 Y68N C153 5-7 79 Y68G C194 7 43 Y68W C196 4-5 108 N71D H455 5 110 N71S H481 7 55 G120A D127 4-5 160 G120S D171 4-6 125 F124Q I83 8 39 F124A I104 7-9 20 F124V I115 7-9 37 F124M I116 9 33 F124L I136 7-9 38 F124C I138 7-9 36 F124S I211 7-9 41 F124N I229  8-10 21 F124T I267 7-9 56 F124T I329 7-8 87 F124H I336 7-9 41 F124H I388 7-9 41 F124K I399  8-10 23 F124G I453 7 49 F124Y I472 5-7 66 F124W I505 5-7 56 F124A I104 7-9 32 F124V I115 7-9 53 N71S F124K 139CB1 9 16 Y68G F124Q 139DC1 4 143 Y68G F124W 139EC8 5-7 69 EXAMPLE 2 Adenoviral-Mediated Expression of NTR Mutants F124N and F124K/N71S Sensitises Cancer Cells to CB1954 to a Greater Extent than Expression of the WT Enzyme [0120] In initiating this work, the assumption was made that improved versions of the E. coli NTR enzymes identified using a bacterial screening system would also activate CB1954 “more efficiently” than the WT enzyme in human cancer cells (so reducing the intratumoral CB1954 concentration and/or the duration of exposure of tumour cells to the drug required to generate sufficient activated prodrug for cell killing). [0121] In this example we describe experiments that compare the efficiencies with which WT NTR and two mutant enzymes identified in the bacterial screen (F124N and F124K/N71S) sensitise a human cancer cell line (HeLa) to CB1954. [heading-0122] Methods [heading-0123] Virus Construction [0124] NTR expression in HeLa cells was achieved by recombinant adenoviral mediated gene transfer. E1-deleted adenoviruses expressing the mutant enzymes were designed to be identical to the WT-expressing virus, “CTL102” (Djeha et al 2000) except for the respective coding change. The F124N coding sequence and 5′ flanking sequence was PCR amplified from the respective lambda phage using forward primer JG138A (5′-GCACGCTAGCAAGCTTCCACCATGGATATCATTTCTGTCGCC-3′) (SEQ ID NO:16) and reverse primer JG138B (5′-GCACAAGCTTGCTAGCTCATTACACTTCGGTTAAGGTGATG-3′) (SEQ ID NO:17). The product was cut with NheI and cloned into the XbaI site of pBluescript (Stratagene). A HindIII-BamHI fragment containing F124N was excised from the resultant plasmid and cloned into HindIII-BamHI digested pTX0374 (Djeha et al). A HindIII fragment containing the CMV promoter/enhancer was then cloned into the resultant vector. The Kozak consensus sequence present in the F124N (AAGCTT.CCA.CCATGg) (SEQ ID NO:18) differed from that present in the WT NTR expressing virus (AAGCTT.GCC.GCC.AGCCATGg) (SEQ ID NO:19). It was therefore removed by Ncol digestion and replaced with the equivalent Ncol fragment from pTX0374 (a plasmid containing wild type NTR used to construct CTL102). The CMV.F124N fragment was then cut out using SmaI and NheI, blunted and cloned into PmeI-digested vector pTX0398 (the transfer vector pPS1128 described in Djeha et al2000 but containing a PmeI site). [0125] The F124K/N71S coding sequence and 5′ flanking sequence were PCR amplified from the respective lambda phage using primers SC1 (5′-AGTCCAAGCTTGCCGCCAGCCATGGATATCATTTCTGTCGCCTTAAAGCG-3′) (SEQ ID NO:20) and SC2 (5′-TGAGGATCCTTACACTTCGGTTAAGGTGATGTTTTGC-3′) (SEQ ID NO:21) which (i) introduced a unique HindIII site at the start of the NTR coding sequence and (ii) incorporated the CTL102 Kozak sequence. A BamHI site was introduced at the 3′ end of NTR to enable F124K/N71S to be cloned into HindIII-BamHI-cut pTX0374 as a HindIII-BamHI fragment. A HindIII fragment containing the CMV promoter/enhancer was then cloned into this vector. The CMV.F124KN71S fragment was then cut out using SpeI and cloned into SpeI digested pPS1128. Recombinant adenoviruses expressing respectively NTR F124N (“CTL802”) and F124K/N71S (“CTL805”) were rescued by homologous recombination in PerC6 cells and purified stocks prepared and titred as described for CTL102 (Djeha et al 2000). [heading-0126] CB1954 Sensitisation Experiments [0127] Sensitisation of HeLa cells to CB1954 was assayed using the following protocol. Cells were infected with NTR-expressing viruses in suspension (2 hours) at a range of MOIs prior to plating into microtitre plates (10 4 cells/well). After a 24 hour expression period, CB1954 was applied at a range of concentrations (0-50 μM) and after a 5 hour exposure to the prodrug, cell viability was assessed using the Promega MTS cell substrate killing assay (2-3 hour incubation before plate reading at OD450 nm). Under these conditions, for a given MOI and [CB1954], expression of both F124N and F124KN71S was consistently found to result in more extensive cell killing than that caused by expression of the WT enzyme. Adenovirus titreing by plaque formation on helper cells is however an error-prone process. To correct for this, experiments were performed with multiple independent titred preparations of each virus. [heading-0128] Results [0129] FIG. 10 A , B, and C shows the results of an experiment in which the viruses used comprised a mixture of three preparations of each NTR-expressing virus (1:1:1). The titres of these mixes were assumed to be the means of the respective experimentally determined titres. For western blot analysis of NTR expression for normalisation purposes, whole cell extracts were resolved by SDS-PAGE on an 11% separation gel and blotted onto a nitrocellulose membrane. NTR was detected using a sheep anti-NTR serum (1:1000 diluted), donkey anti-sheep IgG labelled with HRP (horseradish peroxidase) and SuperSignal West Pico Chemiluminescence substrate (Pierce), analysed with an Alpha Innotech Imager Model #2.3.1. The relative loading of each well was determined by Coomassie blue staining of the gel post transfer. [0130] As shown, at almost all MOIs and CB1954 concentrations used, CTL802 mediated greater sensitisation to CB1954 killing than CTL102. CTL805 mediated a greater effect still. Although in this experiment the improved killing achieved with F124N was moderate, the western blot in FIG. 11A shows that the level of F124N expression was lower than in WT NTR-expressing cells. This provides support for F124N possessing an improved capacity to activate CB1954 in cancer cells but possibly points to a reduced stability compared to WT. The killing due to F124KN71S expression was more marked. In this case however the level of enzyme expression was more similar to that of WT. Overall the data are consistent with the double mutant enzyme possessing more CB1954-activating activity than the WT enzyme. [0131] In conclusion this experiment provides evidence that the F124N and F124K/N71S NTR mutants isolated using the bacterial screen can sensitise a human cancer cell line to CB1954 more effectively than the WT E.coli enzyme. EXAMPLE 3 Kinetic Characterisation of Mutant NTRs [0132] The observation that expression of certain NTR mutants increased the sensitization of E. coli to CB1954 beyond that observed with the WT enzyme was consistent with the mutant enzymes possessing increased catalytic activity. This was examined by kinetic analysis of selected mutants in vitro. [0133] Wild type NTR and selected mutants were purified as described by Lovering et al., 2001. Steady state kinetic studies were carried out by monitoring the disappearance of nitrofurazone ( =12,960, Zenno, et al., 1994) and nitrofurantoin ( =12,020, McOsker, et al., 1992) at 420 nm or the disappearance of reduced benzoquinone ( =18,5000), 2-nitrofuran ( =10,250, McOsker, et al., 1992), 2-nitrobenzamide ( =9,750, McOsker, et al., 1992) and 4 nitrobenzamide ( =9,720, McOsker, et al., 1992) at 300 nm. The formation of the 4 hydroxylamine product of CB1954 reduction was monitored at 420 nm ( =7900, Richard Knox, personal communication). [0134] All reactions were performed in quartz cuvettes with either a 0.1-, 0.5-, or 1-cm pathlength. In all cases the reaction was initiated by the addition of a small amount of cold enzyme solution to the reaction mix. Assays were performed in 10 mM Tris HCL pH 7.0. The temperature of each reaction was maintained at 25° C. by means of a circulating water bath. All substrates examined were dissolved in DMSO, with the final concentration of organic solvent not exceeding 4% (v/v), concentrations>5% (v/v) give definable enzyme inhibition. In all assay the final DMSO concentration was at 4%. All steady state data were collected in an aerobic environment. Kinetic data were collected at concentration ranges extending from 0.1 of K m to the maximum possible concentration permitted by substrate solubility or optical absorbance. In all cases maximum substrate concentrations exceeded 5×K m . All data was analysed using the commercial package Sigma Plot™ and fit with non-linear regression to a rectangular hyperbola of the form: y=ax/b+x [0135] The results shown in FIG. 12A , B and C and Table 4 show that all mutants analysed showed an improvement in either K m for CB1954 or k cat . None displayed an improvement in both parameters. The mutant displaying the best bimolecular rate constant vs. the second substrate was T41L. F124H and F124K both showed significant improvement in k cat /K m for both nucleotide and second substrate. Y68G displayed a large improvement in catalytic activity vs. second substrate but not in k cat /K m as this was offset by an increased Km for CB1954. Overall these data provide evidence that improved catalytic activity underlies the improved efficiency of sensitization of E.coli to CB1954 with respect to the WT NTR enzyme. TABLE 4 Kinetic parameters of a series of selected NTR mutants Enzyme Fixed substrate Variable substrate K m (μM) k cat (min −1 ) k cat /K m Wild type Nitrofurazone NADH 7 ± 1 657 ± 23 98 ± 18 NADH CB1954 852 ± 8  342 ± 25 0.4 ± 0.1 NADH Nitrofurazone 157 ± 4  683 ± 3  4 ± 1 F124H Nitrofurazone NADH   3 ± 0.4 619 ± 13 193 ± 33  NADH CB1954 526 ± 10  356 ± 35 0.7 ± 0.2 NADH Nitrofurazone 104 ± 10  643 ± 16 6 ± 2 F124K Nitrofurazone NADH   1 ± 0.2 723 ± 9  516 ± 43  NADH CB1954 371 ± 12  343 ± 43 0.9 ± 0.1 NADH Nitrofurazone 53 ± 5  758 ± 15 14 ± 3  T41L Nitrofurazone NADH 5 ± 2 2111 ± 35  430 ± 20  NADH CB1954 871 ± 77  972 ± 82 1.1 ± 0.2 NADH Nitrofurazone 79 ± 11 2108.4 ± 36.7  27 ± 3  Y68G Nitrofurazone NADH 22 ± 1  3286 ± 33  146 ± 23  NADH CB1954 1841 ± 44  690 ± 54 0.4 ± 0.1 NADH Nitrofurazone 699 ± 24  3541 ± 24  5 ± 1 References [0137] 1. Djeha A H, Hulme A, Dexter M T, Mountain A, Young L S, Searle P F, Kerr D J, Wrighton C J (2000). Expression of Escherichia coli B nitroreductase in established human tumor xenografts in mice results in potent antitumoral and bystander effects upon systemic administration of the prodrug CB1954. Canver Gene Therapy 7: 721-731. [0138] 2. Friedlos F, Quinn J, Knox R J and Roberts J J (1992). The properties of total adducts and interstrand crosslinks in the DNA of cells treated with CB 1954. Exceptional frequency and stability of the crosslink. Biochem Pharmacol 43: 1249-1254. [0139] 3. Grove J I, Searle, P F, Weedon, S J, Green N K, McNeish I A and Kerr D J (1999). Virus-directed enzyme prodrug therapy using CB1954. Anti-Cancer Drug Design 14: 461-472. [0140] 4. Knox R J, Friedlos F, Jarman M and Roberts J J (1988). A new cytotoxic, DNA interstrand crosslinking agent, 5-(aziridin-1-yl)-4-hydroxylamino-2-nitrobenzamide, is formed from 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB1954) by a nitroreductase enzyme in Walker carcinoma cells. Biochem Pharmacol 37: 4661-4669. [0141] 5. Knox R J, Friedlos F, Marchbank T and Roberts J J (1991). Bioactivation of CB 1954: reaction of the active 4-hydroxylamino derivative with thioesters to form the ultimate DNA-DNA interstrand crosslinking species. Biochem Pharmacol 42: 1691-1697. [0142] 6. Lovering A L, Hyde E I, Searle P F and White S A (2001). The structure of Escherichia coli nitroreductase complexed with nicotinic acid: three crystal forms at 1.7 Å, 1.8 Å, and 2.4 Å resolution. J Mol Biol 309: 203-213. [0143] 7. McNeish I A, Searle P F, Young L S and Kerr D J (1997). Gene-directed enzyme prodrug therapy for cancer. Advanced Drug Delivery Reviews 26: 173-184. [0144] 8. McOsker C C and Fitzpatrick P M (1994). Nitrfurantoin: mechanism of action and implications for resistance development in common uropathogens. J Antimicrob Chemother 33 Suppl A:23-30. [0145] 9. Parkinson G N, Skelly J V and Neidle S (2000). Crystal structure of FMN-dependent nitroreductase from Escherichia coli B: a prodrug-activating enzyme. J Med Chem 43: 3624-3631. [0146] 10. Zenno S, Koike H, Tanokura M and Saigo K (1996). Conversion of NfsB, a minor Escherichia coli nitroreductase, to a flavin reductase similar in biochemical properties to FRase I, the major flavin reductase in Vibrio fischeri, by a single amino acid substitution. J Bacteriology 178: 4731-4733. [0147] All references cited herein are hereby incorporated by reference in their entireties. OTHER EMBODIMENTS [0148] Other embodiments will be evident to those of skill in the art. It should be understodd that the foregoing detailed description is provided for clarity only and is merely exemplary. The spirit and scope of the present invention are not limited to the above examples, but are encompassed by the following claims.

Improved nitroreductase enzymes, particularly for use as prodrug converting enzymes are provided. In particular, single and double mutants of the E. coli NFSB nitroreductase, having improved properties for the activation of the prodrug CB 1954 for use in gene therapy are disclosed.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro analytical method, a sampling plate used in the same, a method of detecting organic compounds by the use of the micro analytical method, and an apparatus for the same. 2. Description of the Prior Art Micro analytical methods using, for example, a microscopic FTIR (Fourier Transform Infrared Ray Spectrophotometer), a FTIR with a beam condenser, a FTIR with a condensing lens and the like have been suitable for an analysis of a very small quantity of minute organic matter, but a disadvantage has occurred in the conventional means for condensing a very small quantity of sample in that a condensed sample is diffused to reduce the thickness thereof, thereby reducing the sensitivity. That is to say, a very small quantity of solution of a solute in a solvent has been deposited drop by drop on a mirror-finished metallic base by the use of an instrument, such as a riffle sampler, and the solvent in the solution has been evaporated to condense the solute on the base, which condensed solution has been used as the sample. However, by this condensing means, the solution deposited drop by drop on the base has been expanded all over said mirror-finished surface of the base and diffused in the form of islands to be condensed, so that the thickness of said sample has been apt to be reduced. More concretely speaking, in the case where 1 μl of a solution of 10 μl of fluid paraffin in 100 ml of acetone has been deposited drop by drop on the base, the solution has been immediately expanded to a circle having a diameter of 3 to 5 mm. The solvent begins to evaporate from a circumferential portion of said circle and at the same time the solute is turned into numerous islands. These islands of solute are condensed in the form of a ring having a diameter of 3 to 5 mm, whereby the thickness of the sample is remarkably reduced. In this case, the absorption of infrared rays was insufficient. Concretely speaking, a transmission factor of infrared rays measured by a microscopic FTIR/FT-530 (made by HORIBA, Ltd.) was about 98% at a wave number of about 1,450 cm -1 as shown in FIG. 38. That is to say, the absorbing degree of light is remarkably low to an extent of 0.01 and thus a highly accurate analysis by the microscopic spectrometric analytical method was difficult. In addition, the above-described expansion of the solution has no orientation, so that it has been difficult to fix positions where the solute is to be condensed in an appointed manner. This has led to difficulty in the automation of the spectrometric analysis. Furthermore, disadvantages have occurred in that if positions, where the solution is deposited drop by drop, are allowed to approach so that the solution may be deposited drop by drop at many points compared with the size of a sample table, the solutions deposited drop by drop are brought into contact with each other according to the expansion thereof or the solution deposited drop by drop is attracted to the already condensed sample so as to be brought into contact with it. By the way, after FTIR has been widely used recently, the so-called HPLC/FTIR, in which a solvent in a solution eluted from HPLC (high-speed liquid chromatography) is removed to be used as a sample in FTIR, has been proposed to be practically used. Methods of measuring as the above described HPLC/FTIR include for example (1) A method in which an eluted solution is heated, concentrated and removed in sequential phase mode and then a solute is measured by the diffusion-reflection method or the transmission method; (2) A method in which water is replaced by acetone and methanol by the use of 2,2-dimethoxypropane and acids in an inverted phase mode and acetone and methanol are heated to evaporatively remove solvents and then a solute is measured by the diffusion-reflection method or the transmission method; (3) A method in which a solute is extracted by the use of chloroform or dichloromethane having a comparatively narrow absorption band in a sequential phase mode to measure a spectrum thereof by the transmission method in the form of liquid or a solvent is evaporatively removed and then a spectrum of a solute is measured by the diffusion-reflection method or the transmission method; and the like. In any of the above described methods, the sample is irradiated with infrared rays and an absorption spectrum resulting from a vibration causing a change in a dipole moment of molecular vibrations is measured. In these methods, an infrared absorption is characterized in having absorption wavelength bands peculiar to organic functional groups and thus can be applied for qualitatively or quantitatively determining organic functional groups, discriminating similar compounds, making reaction mechanisms clear and analyzing structures, and additionally can analyze a multi-component system comprising at least several kinds of components. However, disadvantages have occurred in that not only is the sensitivity several hundred ng (10 -9 g) and thus it is unsuitable for a measurement of a very small quantity of component, but also HPLC and the exclusive FTIR are required and thus an apparatus is large-scaled and expensive. In the case where the FTIR is provided with the above-described HPLC, as shown in FIG. 39, a passage 87 connected with a detector 85 of a liquid chromatograph 86 comprising an eluted liquid tank 81, a liquid-sending pump 82, a sample-injecting portion 83, a partition column 84, detector 85 and the like is provided with a branching T-type joint 88 at an end thereof, tubes 89, 90 having suitable inside diameters being connected with joint 88, and one tube 89 being connected with an analyzer 91 while the other tube 90 is connected with an exhaust passage (not shown). In addition, reference numeral 92 designates a syringe for injecting the sample and reference numeral 93 designates a recorder. In order to set a flow rate of a liquid flowing through each tube 89, 90, respectively, for example the following measures have been used: 1 The inside diameters of the tubes 89, 90 are changed; 2 Lengths of the tubes 89, 90 are changed; and 3 The tube 89 connected with analyzer 91 is provided with flow rate-setting means such as a needle valve. However, according to the above described 1, the ratio of the flow rate of the liquid flowing through tube 89 to that of the liquid flowing through tube 90 is equal to the ratio of the square of the diameters but cannot be continuously changed. According to 2, a continuous ratio can be obtained but not a length from detector 85 of liquid chromatograph 86 to analyzer 91 is changed and thus the time required for the movement of liquid is varied, but also long tubes are required in order to obtain an increased ratio. In addition, according to 3, although not only a continuous ratio can be obtained but also the time required for the movement of liquid is not varied. For example, in case of an eluted liquid, a problem has arisen in that the current of the eluted liquid is made turbulent by the needle valve to expand a chromatogram, whereby it becomes difficult to maintain resolution power. SUMMARY OF THE INVENTION The present invention has been achieved paying attention to the above described matters. It is a first object of the present invention to develop means for coherently condensing a solution, to provide a micro spectrometric analytical method capable of analyzing a sample in high sensitivity even though a very small quantity of minute solution is used as the sample, and to provide a sampling plate used in the method. It is a second object of the present invention to provide a method of detecting organic compounds capable of analyzing also a very small quantity of component in high sensitivity by the use of the micro analytical method and an inexpensive apparatus simple in construction for detecting organic compounds. In addition, it is a third object of the present invention to provide a method of making a liquid branch capable of dividedly sampling a micro-liquid flow, such as eluted liquid in a liquid chromatograph, at an optional ratio. That is to say, one of the basic micro spectrometric analytical methods according to the present invention is characterized in that a very small quantity of solution of a solute in a solvent is deposited drop by drop on a thin film made of water-repellent resins, such as fluoride family resins, mounted on an infrared ray-reflecting member of a sample table, said solvent being evaporated to use the condensed solution as the sample, the sample being positioned at a micro spectrometric analytical portion together with the sample table to be irradiated with infrared rays, and a spectrum reflected from said infrared ray-reflecting member through the sample being measured. And, a further basic micro spectrometric analytical method according to the present invention is characterized in that a very small quantity of solution of a solute in a solvent is deposited drop by drop on a base made of water-repellent resins, said solvent being evaporated to be condensed, the condensed solution to be used as the sample being transferred to an infrared ray-reflecting material, the sample being positioned at a micro spectrometric analytical portion together with the infrared ray-reflecting material to be irradiated with infrared rays, and a spectrum reflected from the infrared ray-reflecting material through the sample being measured. In addition, a still further basic micro spectrometric analytical method according to the present invention is characterized in that a very small quantity of solution of a solute in a solvent is deposited drop by drop on a thin film made of water-repellent resins of a sample table provided with the thin film mounted on an infrared ray-transmitting portion, the solvent being evaporated to use the condensed solution as the sample, the sample being positioned at a micro spectrometric analytical portion together with the sample table to be irradiated with infrared rays, and a spectrum, which is transmitted through the sample and the sample table, being measured. Furthermore, a still further basic micro spectrometric analytical method according to the present invention is characterized in that a very small quantity of solution of a solute in a solvent is deposited drop by drop on a base made of water-repellent resins, the solvent being evaporated to be condensed, the condensed solution to be used as the sample being transferred to an infrared ray-transmitting material, the sample being positioned at a micro spectrometric analytical portion together with the infrared ray-transmitting material to be irradiated with infrared rays, and a spectrum, which is transmitted through the sample and the infrared ray-transmitting material, being measured. In the above described respective inventions, the solution deposited drop by drop on a surface of the water-repellent resins is not only limited in diffusion thereof to hold a spherical shape by surface tension but also the diameter of the spherical shape is gradually reduced with evaporation of the solvent, whereby nonvolatile substances, that is, the solute, are coherently condensed, and a condensed sample having a reduced expansion and an increased thickness is obtained. The condensed sample has an increased thickness. Thus, the infrared ray-absorbing intensity by the sample in the micro spectrometric analytical portion is heightened. As a result, the solution containing the solute can be analyzed in high sensitivity by an analytical method in which infrared rays reflected or transmitted through the solution are measured, even though a very small quantity of solution containing the solute is used as the sample. In the present invention, in order to more progressively develop the above described basic micro spectrometric analytical methods, the following micro spectrometric analytical method has been proposed. That is to say, pinholes, which become condensing nuclei of the solution of the solute in the solvent, may be formed on the base made of the water-repellent resins at appointed intervals to deposit a very small quantity of solution drop by drop on portions where the pinholes have been formed, whereby the solution is condensed by evaporating the solvent. In addition, pinholes, which become condensing nuclei of the solution of the solute in the solvent, may be formed on a thin film made of water-repellent resins of a sample table provided with the thin film mounted on an infrared ray-transmitting material at appointed intervals to deposit a very small quantity of solution drop by drop on portions where pinholes have been formed, whereby the solution is condensed by evaporating the solvent. In the case where the pinholes are formed on the base made of water-repellent resins or on the thin film made of water-repellent resins of the sample table provided with the thin film mounted on the infrared ray-transmitting material in the above described manner, the solution deposited drop by drop on portions where the pinholes have been formed, of a surface of this fluoride family resin is not only limited in diffusion thereof to hold a spherical shape around the pinholes by surface tension, but also the solute is coherently condensed so that the diameter of the spherical shape may be gradually reduced with evaporation of the solvent with the pinholes as the condensing nuclei, and the condensed sample having a reduced expansion and an increased thickness is obtained with the solute arranged orderly at appointed positions with the pinholes as centers. The condensed sample has an increased thickness and thus the infrared ray-absorbing intensity of the sample in the micro spectrometric analytical portion is heightened. As a result, the solution containing the solute can be analyzed in high sensitivity by an analytical method in which infrared rays reflected or transmitted through the solution are measured, even though a very small quantity of solution containing the solute is used as the sample. In addition, the condensed samples are arranged orderly with the pinholes as the centers, so that automation of the spectrometric analysis is also possible. Furthermore, the surface of the thin film made of the water-repellent resins mounted on the infrared ray-reflecting material of the sample table may be irradiated with laser beams or ultraviolet rays at appointed intervals in place of formation of pinholes to reduce the surface tension of very small zones and then a very small quantity of solution of the solute in the solvent may be deposited drop by drop on these very small zones to condense the solution by evaporation of the solvent. The surface of the base made of the water-repellent resins may also be irradiated with laser beams or ultraviolet rays at appointed intervals to reduce the surface tension of very small zones and then a very small quantity of solution of the solute in the solvent may be deposited drop by drop on the very small zones to condense the solution by an evaporation of the solvent. If the very small zones (having an area of 20 μm×20 μm, for example) of the surface made of the water-repellent resins are irradiated with laser beams or ultraviolet rays in the above described manner, the surface of the resins is denatured by this irradiation to reduce the surface tension of the irradiated zones. The solution deposited drop by drop on the denatured very small zones is limited in diffusion by the surface tension of portions of the water-repellent resins surrounding the denatured very small zones and is condensed with the denatured very small zones as centers, whereby a relatively thick sample is formed. Accordingly, the sample can be provided in an orderly arrangement with the denatured very small zones as centers. The infrared ray-absorbing intensity of the sample in the micro spectrometric analytical portion is heightened by using a relatively thick sample. As a result, the sample can be analyzed in high sensitivity by an analytical method in which reflected or transmitted infrared rays passing through the sample are measured, even though a very small quantity of minute sample is used. In addition, the samples are provided in an orderly arrangement with the denatured very small zones as centers, so that automation of the spectrometric analysis is also possible. Furthermore, in the present invention, a method of detecting organic compounds by the use of the above described micro spectrometric analytical method is proposed. That is to say, a method of detecting organic compounds according to the present invention is characterized in that a liquid eluted from a column of a liquid chromatograph is deposited drop by drop on a thin film made of water-repellent resins and a sample of organic compounds coherently concentrated on the thin film is irradiated with infrared rays to detect reflected infrared rays obtained at that time and measure an absorbing degree of the reflected infrared rays, thereby detecting the presence of organic compounds and their concentration. In this case, the liquid eluted from the column of the liquid chromatograph may be deposited drop by drop on the thin film made of water-repellent resins and the sample of organic compounds coherently concentrated on the thin film may be irradiated with infrared rays to detect transmitted infrared rays and measure the absorbing degree of the infrared rays, thereby detecting the presence of organic compounds and determining the concentration thereof. According to the above described method of detecting organic compounds, the liquid eluted from the column of the liquid chromatograph is coherently condensed on the thin film made of the water-repellent resins to form a condensed sample having a reduced expansion and an increased thickness. This sample is irradiated with infrared rays to measure the absorbing degree of the infrared rays, whereby the presence and concentration of organic compounds can be detected. In addition, in the present invention, there is proposed a method of making liquid flowing through one passage branch into two passages at a junction. That is to say, the method of making a liquid branch according to the present invention is characterized in that the respective outlet ends of two branched passages are relatively changed in height so that the ratio of the flow rate of a liquid flowing through one passage to that of a liquid flowing through the other passage may be changed. In this method of making a liquid branch, in the case where, for example, the two branched passages are formed by tubes having a ratio of sectional areas of 1:4, the liquid flows through the respective branched passages in a flow rate corresponding to the ratio of sectional areas if the outlet ends of both branched passages are horizontal. However, if the outlet end of the branched passage having the larger diameter is lowered while keeping the outlet end of the branched passage having the smaller diameter horizontal, the liquid correspondingly flows through the branched passage having the larger diameter at a flow rate larger than that corresponding to the original ratio of sectional areas. On the contrary, if the outlet end of the branched passage having the smaller diameter is lowered while keeping the outlet end of the branched passage having the larger diameter horizontal, the liquid correspondingly flows through the branched passage having the smaller diameter at a flow rate larger than that corresponding to the original ratio of sectional areas. BRIEF DESCRIPTION OF THE DRAWINGS The basic micro spectrometric analytical methods according to the present invention are shown in FIGS. 1 to 9, in which FIG. 1 is a diagram showing the principle of a micro spectrometric analytical method using reflection of infrared rays; FIG. 2 is a diagram showing a solution deposited drop by drop on a sample table; FIG. 3 is a diagram showing a solvent which is being evaporated from the solution; FIG. 4 is a diagram showing a condensed condition of the solution; FIG. 5 is a diagram showing a condensed sample pressed so as to be flat; FIG. 6 is a sectional view showing control means for controlling the speed of evaporation of solvent; FIG. 7 is a diagram showing a sample table according to another preferred embodiment using reflection of infrared rays; FIG. 8 is a diagram showing the principle of a micro spectrometric analytical method using transmission of infrared rays; and FIG. 9 is a diagram showing a sample table according to another preferred embodiment using transmission of infrared rays. The micro spectrometric analytical methods progressively developed from the above described basic micro spectrometric analytical methods, more concretely the micro spectrometric analytical method with pinholes becoming condensing nuclei of a solution formed on a surface of a sample table, are shown in FIGS. 10 to 16, in which FIG. 10 is a diagram showing the principle of a micro spectrometric analytical method using reflection of infrared rays; FIG. 11 is a diagram showing a solution deposited drop by drop on portions where pinholes are formed; FIG. 12 is a diagram showing a solution deposited drop by drop on a sample table; FIG. 13 is a diagram showing a solvent which is being evaporated from a solution; FIG. 14 is a diagram showing the condensed condition of a sample; FIG. 15 is a plan view showing the condensed condition of a sample on a sample table; and FIG. 16 is a diagram showing a sample table according to another preferred embodiment using reflection of infrared rays. The micro spectrometric analytical methods progressively developed from the above described basic micro spectrometric analytical methods, more concretely the micro spectrometric analytical method with denatured very small zones formed on the surface of a sample table, are shown in FIGS. 17 to 24, in which FIG. 17 is a diagram showing the principle of a micro spectrometric analytical method using reflection of infrared rays; FIG. 18 is a plan view showing a solution L deposited drop by drop on denatured very small zones; FIG. 19 is a diagram showing one example of apparatus for putting a mask-imaging method into practice; FIG. 20 is a diagram showing the relation between the power of laser beams applied and the abrasion zone; FIG. 21 is a diagram showing a solution deposited drop by drop on a sample table; FIG. 22 is a diagram showing a solution which is being evaporated; FIG. 23 is a diagram showing the condensed condition of a sample on a sample table; and FIG. 24 is a diagram showing a sample table according to another preferred embodiment using reflection of infrared rays. FIG. 25 is a diagram showing transmission characteristics of infrared rays obtained by the micro spectrometric analytical method according to the present invention. The methods of detecting organic compounds by the use of the above described micro spectrometric analytical methods are shown in FIGS. 26 to 33, in which FIG. 26 is a diagram roughly showing one example of a construction of an apparatus for detecting organic compounds by the use of the above-described micro spectrometric analytical method; FIG. 27 is a perspective view showing one example of the sample table in the above-described apparatus; FIG. 28 is a sectional view showing the sample table; FIGS. 29(A)-29(C) are diagram schematically showing a process of coherently condensing a solution on the sample table; FIG. 30(A) is a chromatogram obtained by an ultraviolet detector in conventional liquid chromatograph; FIG. 30(B) is a chromatogram obtained by an ultraviolet detector in liquid chromatograph according to the present invention; FIG. 30(C) is a chromatogram obtained by an infrared ray detector of a micro spectrometric analyzer according to the present invention; FIG. 31 is a diagram showing the change of spot diameter with the lapse of evaporating time when solutions of Triton in various kinds of solvent are deposited drop by drop on a thin film made of water-repellent fluoride resins; FIG. 32 is a diagram showing the relation between the concentration and final diameter of residues in solutions of Triton and 1, 5-dihydroxynaphthalene, respectively, in acetonitrile and methanol, respectively; and FIG. 33 is a diagram roughly showing the construction of an apparatus for detecting organic compounds according to another preferred embodiment of the present invention. FIG. 34 is a diagram showing a method of making a liquid flowing through one passage branch into two passages at a junction. FIG. 35 is a diagram showing one example of a branching T-type joint to which the above described method of making a liquid branch is applied. FIG. 36 is a graph showing the change of shunting ratio when a liquid is made to branch into two pieces of tube having inside diameters different from each other. FIG. 37 is a graph showing the change of shunting ratio when a liquid is made to branch into two pieces of tube having inside diameters equal to each other. FIG. 38 is a diagram showing transmission characteristics of infrared rays using a conventional method of making a liquid branch. FIG. 39 is a diagram showing a conventional method of making a liquid branch. DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the basic micro spectrometric analytical methods according to the present invention will be described. FIG. 1 is a diagram showing the principle of a micro spectrometric analytical method using reflection of infrared rays. Referring to FIG. 1, reference numeral 1 designates a sample table arranged in, for example, a micro spectrometric analytical portion of FTIR for holding a sample S. Reference numeral 2 designates a light source for irradiating sample S on sample table 1 with infrared rays IR, reference numeral 3 designating a spectrum-measuring device for measuring the reflected spectrum of infrared rays IR from sample S, which is quantitatively or qualitatively determined by spectrum-measuring device 3 on the basis of measured information from the reflected spectrum. The sample table 1 according to this preferred embodiment is provided with a thin film 5 made of fluoride resins rich in water-repellency of, for example, 25 μm in thickness (preferably 16 μm or 8 μm in order to reduce suppressed absorption of infrared rays) mounted on a mirror-finished portion of a mirror-finished metallic infrared ray-reflecting member 4. Spectrum-measuring device 3 measures the spectrum reflected by infrared ray-reflecting member 4 through sample S and thin film 5 made of fluoride resins. The thin film 5 may be, for example, coated on an infrared ray-transmitting member (for example a crystal or film of alkali halide family materials, such as KBr and NaCl) to mount thin film 5 on infrared ray-reflecting member 4 through the infrared ray-transmitting member. In this case, if thin film 5 has pinholes, the pinholes are filled up with the infrared ray-transmitting member to effectively prevent a solution from soaking between thin film 5 and infrared ray-reflecting member 4. On the other hand, the sample S may be, for example, an eluted substance separated by liquid chromatograph and held on thin film 5, made of fluoride resins, which will be mentioned next. That is to say, a very small quantity of a solution L of a solute (which is used as the sample S, as described later) in a solvent is deposited drop by drop on thin film 5 by the use of an instrument such as a riffle sampler, as shown in FIG. 2. Thin film 5 is rich in water-repellency, even in the case where, for example, methanol or ethanol is selected as the solvent, so that the solution deposited drop by drop on thin film 5 is limited in diffusion by surface tension to maintain a spherical shape. If the solvent in solution L is evaporated (naturally or forcibly by means of a heater and the like), as shown in FIG. 3., solution L is reduced in diameter while maintaining a spherical shape to coherently condense nonvolatile substances and form a condensed sample S on thin film 5, as shown in FIG. 4. Up to that time in the process this condensed sample S is relatively thick and has a reduced expansion due to limitation of diffusion of solution L. In this connection, in the case where 1 μl of solution L (10 μl of fluid paraffin in 100 ml of acetone) was deposited drop by drop on thin film 5, solution L exhibited a spherical shape and the solvent was evaporated from a circumferential portion of a spherical surface of solution L to form a relatively thick circular sample S having a diameter of about 100 μm. This condensed sample S is positioned at a micro spectrometric analytical portion together with sample table 1 to carry out a micro spectrometric analysis. Preferably, condensed sample S is pressed by a suitable pressing means 6 to be flattened, as shown in FIG. 5, thereby improving the sensitivity of measurement. The condensed sample S has considerable thickness, so that the infrared ray absorption intensity of sample S in the micro spectrometric analytical portion is heightened. Concretely speaking, a transmission factor of infrared rays measured by a microscopic FTIR/FT-530 (made by HORIBA, Ltd.) was about 10% at a wave number of about 1,450 cm -1 , as shown in FIG. 25. That is to say, the absorbing degree of light is remarkably high to an extent of 1.0, which is 100 times that in the already described conventional methods, so that the analysis of the sample by measuring the reflected spectrum can be achieved in high sensitivity (the sensitivity is improved 100 times as compared with the conventional methods). In addition, the solvent in solution L may be forcibly evaporated by means of a heater and the like rather than evaporated naturally. At this time, if the solvent is evaporated at too high a rate, there is a possibility that the coherence of sample S is apt to be reduced and thus sample S is apt to be expanded, whereby the thickness of condensed sample S is reduced. Means 7 for controlling the rate of forcibly evaporating the solvent is shown in FIG. 6. Controlling means 7 comprises a trestle 9 provided with a heater 8 on a lower surface thereof and an airtight vessel 10 placed over trestle 9. Airtight vessel 10 is provided with a fine tube 12 with an exhaust-controlling valve 11 passing therethrough. The above-described construction leads to the following advantages: That is to say, not only can the solvent in solution L be evaporated under saturated conditions, but also the rate of evaporation of the solvent can be controlled by positioning sample table 1 on trestle 9 to deposit a very small quantity of solution L drop by drop on thin film 5 of sample table 1, placing airtight vessel 10 on trestle 9 so as to cover sample table 1 to generate heat from heater 8, and controlling the displacement by means of control value 11. Thus, not only can the concentricity of sample S be improved, but also solution L and thus condensed sample S can be prevented from being contaminated with the open air. FIG. 7 shows a sample table 1 according to another preferred embodiment in an analytical method using reflection of infrared rays. In this embodiment sample table 1 comprises a base 13 made of fluoride resins and an infrared ray-reflecting member 14, to which condensed sample S on base 13 is transferred. In more detail, solution L is condensed upon base 13 by means shown in FIGS. 2 to 4, transferred to an infrared ray-reflecting member 14 having a mirror finished sample-holding surface, and positioned in a micro spectrometric analytical portion. Such construction leads to the following advantages: That is to say, infrared rays irradiated from light source 2 are absorbed by transferred sample S and reflected by infrared ray-reflecting member 14. The spectrum of the reflected infrared rays in measured by spectrum-measuring device 3. The sensitivity of measurement of the embodiment of FIG. 7 is improved as compared with the micro spectrometric analytical method shown in FIG. 1, due to the absence of thin film 5 in the path of infrared rays reflected from infrared ray-reflecting member 14 to sample S. FIG. 8 is a diagram showing the principle of a micro spectrometric analytical method using transmission of infrared rays according to the present invention. Referring to FIG. 8, reference numerals 15, 16 designate a condensing mirror, reference numerals 17, 18 designate a beam condenser, and reference numeral 19 designates a mask. The sample is quantitatively or qualitatively determined by spectrum-measuring device 3 on the basis of measured information of the spectrum of infrared rays transmitted through sample S. Beam condensers 17, 18 are provided to raise the condensing efficiency. However, the condensing efficiency can also be achieved by omitting beam condensers 17, 18 and instead placing a condensing lens midway of the incident light passage to sample S. The sample table 1 in this preferred embodiment is formed of an infrared ray-transmitting member 20 made of, for example, a crystal of KBr, and provided with a thin film 21 made of fluoride resins. Infrared ray-transmitting member 20 is formed of materials highly transmissive to infrared rays, that is, a crystal or film made of alkali halide family materials, such as NaCl and CaF 2 , in addition to KBr, preferably materials having a reduced solubility Furthermore, if there is no problem in respect of strength, sample table 1 may be composed merely of thin film 21, omitting infrared ray-transmitting member 20. FIG. 9 shows a sample table 1 according to another preferred embodiment in an analytical method using transmission of infrared rays. Referring to FIG. 9, sample table 1 comprises a base 22 made of fluoride resins and an infrared ray-transmitting member 23, to which condensed sample S on base 22 is transferred. In more detail, sample table 1 comprises base 22 made of fluoride resins for condensing the solution L by means shown in FIGS. 2 to 4 and an infrared ray-transmitting member 23 formed of a crystal or film made of alkali halide family materials, such as KBr and NaCl, positioned in the micro spectrometric analytical portion, to which sample S is transferred. According to such construction, infrared rays irradiated from light source 2 are absorbed by transferred sample S and transmitted through infrared ray-transmitting member 23. The spectrum of the transmitted infrared rays is measured by spectrum-measuring device 3. The sensitivity of measurement is improved as compared with the micro spectrometric analytical method shown in FIG. 8 due to the absence of thin film 21 in the path of infrared rays transmitted through sample S. If desired, thin film 5 can be applied to infrared ray-reflecting member 4 or thin film 21 applied to infrared ray-transmitting member 20 by coating a dispersion of fluoride resins or sticking a fluoride resin film upon infrared ray-reflecting member 4 or infrared ray-transmitting member 20, respectively. As above described, in the basic micro spectrometric analytical method according to the present invention, the solvent in solution L is evaporated under conditions such that diffusion is limited by water-repellent resins, such as fluoride resins, upon which solution L is deposited. The solute contained in solution L is thereby coherently condensed, whereby solution L is converted to sample S having substantial thickness and reduced expansion, and condensed sample S is subjected to micro spectrometric analysis by reflection or absorption of infrared rays. The thickness of sample S is remarkably increased compared to conventional methods and the infrared ray-absorbing intensity by sample S is increased. Thus, sample S can be analyzed in high sensitivity by either reflection or transmission of infrared rays according to the analytical method of the present invention even though a very small quantity of original minute solution L is used as the sample S. Next, the methods, which have been achieved by progressively developing the above described basic micro spectrometric analytical method, will be separately described with reference to FIGS. 10 to 33. At first, the invention, in which the pinholes becoming the condensing nuclei are formed on the thin film made of the fluoride resins of the sample table with the thin film made of the fluoride resins mounted on the base made of the fluoride resins or the infrared ray-transmitting member, will be described with reference to FIGS. 10 to 16. FIG. 10 is a diagram showing the principle of the micro spectrometric analytical method by the reflection of infrared rays in the present invention. Referring to FIG. 10, reference numeral 24 designates a large number of pinholes formed in the longitudinal and lateral directions of the thin film 5 made of the fluoride resins at appointed intervals on the thin film 5 made of the fluoride resins, as shown in FIG. 11. Although said pinholes 24 pass through the thin film 5 made of the fluoride resins in the preferred embodiment shown, they may have a concaved shape. The pinholes 24 serve as the condensing nuclei of the solution L of the solute (for example an eluted substance separated by the liquid chromatograph) in a solvent such as methanol or ethanol. Concretely speaking, the pinholes 24 having diameters of 200 μm or less are formed at regular intervals of 5 mm by means of the pointed end of a gimlet. In this preferred embodiment, the sample S is formed as follows: A very small quantity of the solution L of the solute in the solvent is deposited drop by drop on portions, where the pinholes 24 are formed, of the thin film 5 made of the fluoride resins by the use of an instrument such as riffle sampler, as shown in FIG. 11. At this time, the thin film 5 made of the fluoride resins is rich in water-repellency even in the case where for example methanol or ethanol is selected as the solvent, so that he solution deposited drop by drop on the thin film 5 made of the fluoride resins is limited in diffusion thereof to keep a spherical shape by a surface tension thereof, as shown in FIG. 12. In addition, it is preferable that a quantity of the solution L deposited drop by drop is regulated so that a diameter of the solution L, to which a spherical shape has been given when deposited drop by drop, may amount to about 2 mm. And, as shown in FIG. 13, when the solvent in the solution L is evaporated (naturally or forcibly by means of a heater and the like), the solution L is reduced in diameter with keeping the spherical shape thereof to condense nonvolatile substances, that is the solute, and at last, as shown in FIG. 14, the condensate (sample S) composed of merely the solute is formed on the thin film 5 made of the fluoride resins. In the condensation of the solution L, the solution L is condensed so as to be attracted to the pinholes by a surface tension thereof with the pinholes 24 exhibiting a less solid surface tension as centers, so that, as shown in FIGS. 11 and 15, the condensed sample S is orderly formed around centers of the pinholes 24 even though centers of the solution L deposited drop by drop on said portions, where the pinholes 24 have been formed, of the thin film 5 made of the fluoride resins are shifted form said centers of the pinholes 24. This is advantages for an automation of the spectrometric analysis of the sample S. This condensed sample S has a thickness and a reduced expansion due to said limitation of the solution L in diffusion in a process up to that time. In this connection, in the case where 1 μl of the solution L of 10 μl of fluid paraffin in 100 ml of acetone was deposited drop by drop on the thin film 5 made of the fluoride resins, the solution L exhibited a spherical shape and the solvent was evaporated from the surface of the solution L to form the circular sample S having a thickness and a diameter of about 100 μm. It goes without saying that it is preferable to pressedly flatten also this condensed sample S by means of the suitable means shown in FIG. 5, whereby improving the sensitivity of measurement. This condensed sample S was measured on the transmission factor of infrared rays by the microscopic FTIR/FT-530 (made by HORIBA, Ltd.) with the results similar to those shown in FIG. 25. In addition, the solvent in the solution L may be forcibly evaporated by means of said heater and the like other than by a natural evaporation. At this time, if the solvent is evaporated in a too high speed, there is the possibility that a coherence of the sample S is apt to be delayed and thus the sample S is apt to be expanded, whereby reducing the condensed sample S in thickness. Accordingly, it goes without saying that the means 7 for controlling the evaporating speed shown in FIG. 6 may be used. Next, FIG. 16 shows a sample table 1 according to another preferred embodiment used in the analytical method by the reflection of infrared rays but said sample table 1 is different from the sample table 1 show in FIG. 7 merely in that pinholes 24 serving as condensing nuclei of the solution L are formed on a base 13 made of fluoride resins at appointed intervals. In addition, in the case where a thickness was given to said base 13, it is preferable that said pinholes 24 are formed in concaved shape. With such the construction, infrared rays IR irradiated from the light source 2 are absorbed by the transferred sample S and reflected by the infrared ray-reflecting member 14 and a spectrum of the reflected infrared rays is measured by the spectrum-measuring device 3, so that an advantage occurs in that a sensitivity of measurement can be improved as compared with the micro spectrometric analytical method shown in FIG. 10 due to an absence of the thin film 5 made of the fluoride resins in a reflecting surface portion of infrared rays. And, it goes without saying that the micro spectrometric analytical method by the transmission of infrared rays may be used also in the preferred embodiment, in which the pinholes 24 serving as said condensing nuclei of the solution L are formed, and the apparatus is similar to that shown in FIG. 8 or FIG. 9, so that its detailed description is omitted. As above described, in the micro spectrometric analytical method according to the present invention, the solvent in the solution L is evaporated under the condition that the diffusion is limited by the resins, such as fluoride resins, rich in water-repellency to coherently condense the solute contained in the solution L with the pinholes 24 as centers, whereby the solution L is turned into the sample S having a thickness and a reduced expansion, and the condensed sample S is subjected to the micro spectrometric analysis by the reflection or transmission of infrared rays, so that the thickness of the sample S can be remarkably increased as compared with the conventional methods and the infrared ray-absorbing intensity by the sample S can be increased and thus the sample S can be analyzed in high sensitivity by the analytical method by the reflection or transmission of infrared rays even though a very small quantity of original minute solution L is used as the sample S. Moreover, the condensed samples S are orderly arranged with the pinholes 24 as centers, so that it is easily possible also to automate the spectrometric analysis, or, a small spherical shape is given to the solution L, so that the solution L is difficultly brought into contact with other solutions L or the sample S even though portions, where the solution L is deposited drop by drop, are brought close to each other and thus the solution L can be deposited drop by drop on more points as compared with a size of the sample table 1. In addition, with the sample table I according to the present invention, the samples suitable for using in the above described methods, that is the condensed samples S having a thickness and a reduced expansion, can be formed so as to be orderly arranged at appointed positions. Next, the invention, in which the surface of the thin film made of the fluoride resins mounted on the infrared ray-reflecting member of the sample table or the base made of the fluoride resins is irradiated with laser beams or ultraviolet at appointed intervals to reduce a surface tension of very small zones and then a very small quantity of solution of the solute in the solvent is deposited drop by drop on said very small zones to condense the solution by an evaporation of the solvent, is described with reference to FIGS. 17 to 24. FIG. 17 is a diagram showing a principle of the micro spectrometric analytical method by the reflection of infrared rays according to the present invention. Referring to FIG. 17, reference numeral 25 designates a very small denatured zone formed on the thin film 5 made of the fluoride resins of the sample table 1. That is to say, a plurality of very small denatured zones (of for example 20 μm×20 μm) denatured to be reduced in surface tension are formed at appointed intervals in the longitudinal and lateral directions on the thin film 5 made of the fluoride resins as shown exaggerated in FIG. 18. These very small denatured zones 25 are formed by, for example, irradiating with eximer laser beams by a mask-imaging method. FIG. 19 shows one example of apparatus for putting said mask-imaging method into practice. Referring to FIG. 19, reference numeral 26 designates an eximer laser emitting pulse-shaped exima laser beams 27, reference numeral 28 designating a mask with a suitable processing pattern formed thereon by etching, and reference numeral 29 designating a lens for condensing the exima laser beams 27, which have been transmitted through said mask 28, to project them on the thin film 5 made of the fluoride resins of he sample table 1. And, provided that a distance from the mask 28 to said lens 29 is A, a distance from the lens 29 to the thin film 5 made of the fluoride resins being B, and a focal distance of the lens 29 being f. 1/A+1/B=1/f holds good on the basis of the Gaussian theorem. At this time, a contraction factor is M expressed by the following equation: M=A/B In addition, at this time, provided that a density of energy of the eximer laser beams 27 on the mask 28 is E 1 , a density of energy E 2 of the eximer laser beams 27 on the thin film 5 made of the fluoride resins is expressed by the following equation: E.sub.2 =M.sup.2 E.sub.1 Upon irradiating with the eximer laser beams 27 with using the above described apparatus and setting the above described A, B, f and E 1 to suitable values, the thin film 5 made of the fluoride resins of the sample table 1 is nonthermally processed (abraded) to denature a surface thereof with portions irradiated with the eximer laser beams 27 as centers, whereby forming very small denatured zones 25 with the reduced surface tension at suitable intervals. In this case, also circumferential portions of the zones directly irradiated with the eximer laser beams 27 are influenced. That is to say, said surface is changed merely in a mask portion as observed by an optical microscope. In addition, a change is not observed by the microscopic FTIR between the circumferential portions and the fluoride resins not irradiated with the eximer laser beams 27 in infrared spectrum. And, when 1 μl of the solution L containing the solute in the form of liquid (for example the solute is Triton and the solvent is acetonitril) is deposited drop by drop on the fluoride resins, a diameter of the sample after the evaporation of the solvent amounted to 30 μm. It has been found that if a power of the laser beams irradiated is increased, a range influenced by the irradiation with the laser beams is increased, as shown in FIG. 20. In addition, if the mask to be irradiated with the laser beams was increased in size, also said range influenced by the irradiation with the laser beams was increased up to about 7 times the size of the mask. Furthermore, a difference resulting from a film-thickness of the thin film 5 made of the fluoride resins was not observed. Besides, the very small denatured zones 25 may be formed by irradiating with CO 2 laser beams or YAG laser beams. Also ultraviolet rays may be applied. A very small quantity of the solution L of the solute in the solvent is deposited drop by drop on the very small denatured zones 25 on the thin film 5 made of the fluoride resins by the use of an instrument such as riffle sampler, as shown in FIG. 18. At this time, even in the case where for example methanol or ethanol is used as the solvent, the solution L deposited drop by drop on the thin film 5 made of the fluoride resins is limited in diffusion thereof due to a rich water-repellency of the thin film 5 made of the fluoride resins to keep the spherical shape by a surface tension thereof, as shown in FIG. 21. In this case, it is preferable that a quantity of the solution L deposited drop by drop is regulated so that a diameter of the solution L, to which a spherical shape is given when deposited drop by drop, may amount to for example about 2 mm. And, when the solvent in the solution L is evaporated naturally or forcibly by means of a heater and the like, the solution L is condensed with keeping the spherical shape thereof to form the condensed sample S composed of nonvolatile substances on the thin film 5 made of the fluoride resins, as shown in FIG. 22. In the condensation of the solution L, the solution L is condensed so as to be attracted to the very small denatured zones 25 with the very small denatured zones 25 as centers to be orderly formed with the very small denatured zones as centers, as shown in FIG. 23, without being influenced by small foreign matters existing in the very small denatured zones according to circumstances. This is advantageous for an automation of the spectrometric analysis. This condensed sample S has a thickness and a reduced expansion due to said limitation of the solution L in diffusion in a process up to that time. In this connection, in the case where 1 μl of the solution 1 of 10 μl of fluid paraffine in 100 ml of acetone was deposited drop by drop on the thin film 5 made of the fluoride resins, the solution L exhibited a spherical shape and the solvent was evaporated from a circumferential portion of a spherical surface of the solution L to form a disk-shaped sample having a substantial thickness and a diameter of about 100 μm. This condensed sample S was measured on the transmission factor of infrared rays by the microscopic FTIR/FT-530 (made by HORIBA, Ltd.) with the results similar to those shown in FIG. 25. It goes without saying that is preferable to pressedly flatten also this condensed sample S by means of the suitable means 6 shown in FIG. 5, whereby improving the sensitivity of measurement. In addition, the solvent in the solution L may be forcibly evaporated by means of said heater and the like other than by a natural evaporation. At this time, if the solvent is evaporated in a too high speed, there is the possibility that a coherence of the sample S is apt to be delayed and thus the sample S is apt to be expanded, whereby reducing the condensed sample S in thickness. Accordingly, it goes without saying that the means 7 for controlling the evaporating speed shown in FIG. 6 may be used. FIG. 24 shows another preferred embodiment of a sample table used in the analytical method by the reflection of infrared rays. A sample table 1 in this preferred embodiment comprises a base 13 made of fluoride resins with the very small denatured zones 25 formed at appointed intervals and an infrared ray-reflecting member 14 with a mirror-finished sample-holding surface transferredly holding the condensed sample S on said base 13 as the transferred sample and positioned in the micro spectrometric analytical portion. With such the construction, infrared rays IR irradiated from the light source 2 are absorbed by the sample S and reflected by the infrared ray-reflecting member 14 and a spectrum of the reflected member 14 and a spectrum of the reflected infrared rays is measured by the spectrum-measuring device 3, so that an advantage occurs in that a sensitivity of measurement can be improved by an extent due to an absence of the thin film 5 made of the fluoride resins in a reflecting surface portion of infrared rays as compared with the micro spectrometric analytical method shown in FIG. 17. And, it goes without saying that the micro spectrometric analytical method by the transmission of infrared rays may be used also in the preferred embodiment, in which the surface of the thin film 5 made of the fluoride resins or the surface of the base 13 made of the fluoride resins is irradiated with the laser beams or the ultraviolet rays at appointed intervals to reduce the surface tension of the very small denatured zones, and the apparatus is similar to that shown in FIG. 8 or FIG. 9, so that its detailed description is omitted. As above described, in the micro spectrometric analytical method according to the present invention, the solvent in the solution L is evaporated under the condition that the diffusion is limited by the resins, such as fluoride resins, rich in water-repellency to coherently condense the solute contained in the solution L with the very small denatured zones 25 as centers, whereby the solution L is turned into the sample S having a thickness and a reduced expansion, and the condensed sample S is subjected to the micro spectrometric analysis by the reflection or transmission of infrared rays, so that the thickness of the sample S can be remarkably increased as compared with the conventional methods and the infrared ray-absorbing intensity by the sample S can be increased and thus the sample S can be analyzed in high sensitivity by the analytical method by the reflection or transmission of infrared rays even though a very small quantity of original solution L is used as the sample S. The samples S are orderly arranged with the very small denatured zones 25 as centers, so that it is easily possible to automate the spectrometric analysis. In addition, a small spherical shape is given to the solution L, so that the solution L is difficultly brought into contact with other solutions L or the condensed sample S even though portions, where the solution L is deposited drop by drop, are brought close to each other and thus the solution L can be deposited drop by drop on more points as compared with a size of the sample table 1. In addition, with the sample table 1 according to the present invention, the samples suitable for using in the above described methods, that is the condensed samples S having a thickness and a reduced expansion, can be formed so as to be orderly arranged at appointed positions. Next, the method, in which organic compounds are detected by the above described micro spectrometric analytical method, is described with reference to FIGS. 26 to 33. At first, referring to FIG. 26, reference numeral 31 designates a liquid chromatograph comprising an eluted liquid tank 32, a pump 33, a sample injector 35 provided with a syringe 34, a column 36, an ultraviolet ray detector 37 and the like. Reference numeral 38 designates a device for making a liquid branch provided between said column 36 and said ultraviolet ray detector 37 for dividing a liquid eluted from the column 36 into the ultraviolet ray detector 37 and a micro spectrometric analyzer 41, which will be mentioned later, at a suitable shunting ratio (for example 19:1). Reference numeral 39 designates an eluted liquid passage connected with said device for making a liquid branch 38. Said eluted liquid passage 39 is provided with a dropping device 40 (refer to FIG. 27) at a pointed end thereof. In addition, the ultraviolet ray detector 37 is connected with a data-operating portion such as computer (not shown). Reference numeral 41 designates said micro spectrometric analyzer which has the following construction: At first, reference numeral 42 designates a sampler comprising an endless conveying belt 45 extended over a driving pulley 43 and a trailing pulley 44 and moving in an appointed direction at an appointed speed and a sample table 46 fixedly mounted on an upper surface of conveying belt 45 (refer to FIG. 27). Sample table 46 comprises a sampling plate 47 fixed on the upper surface of the conveying belt 45, as shown in FIG. 28, and a thin film 48 made of fluoride resins formed on an upper surface of said sampling plate 47. In this preferred embodiment, the sampling plate 47 is formed of a thin stainless steel plate of for example about 100 μm thick so as to reflect infrared rays. In addition, said thin film 48 made of said fluoride resins is formed by forming for example fluoride resins rich in water-repellency in the thickness of for example about 0.1 μm. And, this thin film 48 made of the fluoride resins is provided with pinholes 49 having diameters of about 200 μm (or less) formed at suitable intervals (for example 8 to 10 mm) on an upper surface thereof by means of for example a pointed end of gimlet. Now, provided that the eluted liquid is discharged from the column 36 of the liquid chromatograph 31 in a quantity of 1 ml/min and said shunting ratio between the side of the ultraviolet ray detector 37 and the side of the micro spectrometric analyzer 41 of the device for making a liquid branch 38 is 19:1, the eluted liquid flows through the eluted liquid passage 39 in a quantity of 50 μl/min. And, provided that a volume of one drop of the solution L deposited drop by drop from a dropping device 40 is 10 μl, 5 drops of the solution L are deposited drop by drop on the sample table 46 every minute. So, it is sufficient to move the conveying belt 45 in the direction shown by an arrow in FIG. 27 at a speed of 50 mm/min. Thus, the solution L is deposited drop by drop on said pinholes 49 on the sample table 46, as shown in FIGS. 27 and 28. The drop-shaped solution L deposited on positions of the pinholes 49 on the thin film 48 made of the fluoride resins rich in water-repellency of the sample table 46 is limited in diffusion thereof to keep a spherical shape by a surface tension thereof, shown in FIG. 29(A). And, when the solvent in the solution L evaporated naturally or forcibly by means of a heater (not shown) the solution L is condensed with keeping said spherical shape to be reduced in diameter, as shown in FIG. 29(B), and at last turned int a coherently condensed sample S, as shown in FIG. 29(C). In short, the solution L deposited drop by drop on the thin film 48 made the fluoride resins is coherently condensed with the pinholes serving as the condensing nuclei formed in the thin film 48 made of the fluoride resins as centers to be turned into said samples S. An apparatus, in which the sample S coherently condensed on the sample table 46 in the above described manner is irradiated with infrared rays and reflected infrared rays are detected, is described. Referring to FIG. 26 again, reference numeral 51 designates an infrared ray-irradiating portion comprising an infrared light source 52, a filter 53, a condensing portion 54 and the like. In addition, reference numeral 55 designates an infrared ray-detecting portion comprising a condensing portion 56, an infrared ray detector 57, an amplifier 58 and the like. Furthermore, said amplifier 58 is connected with said data-operating portion on the output side thereof in the same manner as the ultraviolet ray detector 37. Besides, referring to FIG. 26, reference numeral 59 designates a position irradiated with infrared rays and reference numeral 60 designates a device for rinsing the sample table 46. In operation, at first, in the liquid chromatograph 31, the eluted liquid within the eluted liquid tank 32 is supplied to said sample injector 35 by means of said pump 33 and a sample liquid is introduced into the sample injector 36 by means of said syringe 34. And, said sample is introduced into the column 36 together with the eluted liquid to be subjected to an appointed separating treatment. And, the greater part of the eluted liquid discharged from the column 36 arrives at the ultraviolet ray detector 37 through the device for making a liquid branch 38 to put out a chromatogram, which will be mentioned later, from the ultraviolet ray detector 37. On the other hand, a part of the eluted liquid enters said eluted liquid passage 39 through the device 38 for dividing for micro-liquid flow to arrive at said dropping device 40 through the eluted liquid passage 39. And, this eluted liquid is deposited drop by drop on the sample table 46 by means of the dropping device 40 to be conveyed to said position 59 to be irradiated with infrared rays by means of the conveying belt 45. And, as above described, the eluted liquid is evaporated till it arrives at the position 59 to be irradiated with infrared rays of the micro spectrometric analyzer 41 to be turned into the coherently condensed sample S having an appointed shape. This sample S is irradiated with infrared rays incident upon the sample S pass through the sample S and reflected by the sampling plate 47 below the sample S. The reflected infrared rays are incident upon said infrared ray detector 57 through said condensing portion 56. Thus, a spectrum of the infrared rays, which have passed through the sample S and the thin film 48 made of the fluoride resins and reflected by the sampling plate 47, is measured to put out also a chromatogram, which will be mentioned later, from the infrared ray detector 57. The sample S on the sample table 46 is irradiated with infrared rays in the above described manner but the sample table 46 with the sample S, which has been irradiate with infrared rays, placed thereon arrives at said rinsing device 60 by means of the conveying belt 45 moving in the direction shown by said arrow in FIG. 26 to be rinsed by means of the rinsing device 60, whereby preparing for the following falling of the solution L drop by drop. FIG. 30 shows chromatograms according to the conventional methods and those in the methods according to the present invention in comparison. FIG. 30(A) shows said chromatogram obtained by the ultraviolet ray detector of the conventional liquid chromatograph, FIG. 30(B) said chromatogram obtained by the ultraviolet ray detector 37 of the liquid chromatography 31 according to the present invention, and FIG. 30(C) said chromatogram obtained by the infrared ray detector 57 of the micro spectrometric analyzer 41 according to the present invention. Now, provided that 5 substances A to E are contained in the eluted liquid and merely said substance B does not absorb ultraviolet rays, according to the conventional methods, the chromatogram having peaks corresponding to said substances A, C, D and E excluding the substance B is obtained, as shown in FIG. 30(A). On the contrary, according to the present invention, merely the chromatogram similar to that obtained by the conventional methods is obtained by the ultraviolet ray detector 37 of the liquid chromatograph 31 but the chromatogram obtained by the infrared ray detector 57 of the micro spectrometric analyzer 41 exhibits 5 peaks corresponding to 5 substances A to E, respectively. In short, according to the present invention, an existence of organic compounds, of which detection has been difficult by the conventional methods, can be detected and a substance can be estimated from retention times in the chromatogram of the liquid chromatograph 31. In addition, some supplementary descriptions are added to the chromatogram shown in FIG. 30. Said retention times of the column are determined by the solute, the column and separating conditions, and, the ultraviolet ray detector 37 and the infrared ray detector 57 exhibit the same one retention times under the same one conditions. However, since they do not always coincide with each other in correlation between an ultraviolet ray sensitivity and an infrared ray sensitivity, the substance A is increased in absorbing sensitivity in the infrared ray detector 57 according to circumstances. In the above described preferred embodiment, the following effects are achieve. That is to say, since the solution L is deposited drop by drop on the thin film 48 made of the water-repellent fluoride resins by means of the dropping device 40 to evaporate the solvent, the high-speed measurement can be achieve. FIG. 31 shows a change of spot diameter with the lapse of evaporating time when the solution of Triton in various kinds of solvent was deposited drop by drop on the thin film 48 made of the fluoride resins. A curve A, B, C and D shows the solution L of Triton in water having normal temperature, water of 60° C., methanol having normal temperature and acetonitrile having normal temperature, respectively, at a concentration of 0.1 μg/ml. In addition, a curve E shows the comparative case where the solution L of Triton in water having normal temperature at the above described concentration was deposited drop by drop on a stainless steel plate. It is found from the above described FIG. 31 that when for example water is used as the solvent, 1 μl of water can be evaporated for about 7 minutes at normal temperature and about 2 minutes at 60° C., and, similarly, methanol or acetonitrile can be evaporated for about 2 minutes. As above described, according to the present invention, the solvent is removed from the solution L, so that the infrared absorption spectrum of the substance can be directly measured at every wavelength band within the infrared range. And, since the fluoride resins hardly have a spectrum and have the water-repellency, the spectrum of the substance is not influenced by the thin film 48 made of the fluoride resins even though the thin film 48 made of the fluoride resins is for example 1 μm or less thick. Rather, an absorption by fluorine is reduced and thus a detecting sensitivity is improved. However, if the thin film 48 is reduced in thickness, a control of evaporation and coherence is influenced by pinholes formed in addition to the desired pinholes during the formation of thin film according to circumstances. And, as the solvent is evaporatedly removed, the solute is concentrated with the pinholes 49 as centers, so that a density of the samples S existing on the surface, upon which infrared rays are incident, is increased and thus the absorbing sensitivity is improved. Table 1 shows a coherent effect of the solution L or Triton, which is liquid at normal temperature, and 1,52O-dihydroxynaphthalene, which is solid at normal temperature, in 1 μl of methanol, acetonitrile and water, respectively, at a concentration of 100 μg/ml when the solution L was deposited drop by drop on a substrate made of a stainless steel (SUS), CaF 2 and PFE (fluoride resin), respectively, in an atmosphere of nitrogen gas of 25° C. In addition, Table 1, * represents "insoluble". TABLE 1______________________________________SoluteDiameter (μM)Triton X-100 1,5-dihydroxynaphthaleneSolventMeth. Aceto. H.sub.2 O Meth. Aceto. H.sub.2 O______________________________________SubstrateSUS 12000 4800 3000 12000 5200 *CAF.sub.2 2200 2200 2200 2400 800 *PFP 95 90 180 330 100 *______________________________________ In addition, FIG. 32 shows a relation between a concentration and a final diameter of residues in the solution L of Triton and 1,5-dihydroxynaphthalene, respectively, in acetonitrile and methanol, respectively. In FIG. 32, a curve A shows the solution L of Triton in acetonitrile, a curve B the solution L of Triton in methanol, a curve C the solution L of 1,5-dihydroxynaphthalene in acetonitrile and a curve D the solution L of 1,5-dihydroxynaphthalene in methanol, respectively. It is found from FIG. 32 that said final diameter of residues amounts to about 400 μm at said concentration of 200 μg/ml in the solution L of 1.5-dihydroxynaphthalene in methanol. FIG. 33 roughly shows a construction of an apparatus for detecting organic compounds according to another preferred embodiment. A micro spectrometric analyzer 61 in this preferred embodiment is constructed so as to measure by the transmission of infrared rays. That is to say, that sampling plate 47 is formed of materials transmissive to infrared rays, such as crystals or films made of alkali halide materials, for example NaCl or CaF 2 , and the conveying belt 45 if formed not so as to hinder the transmission of infrared rays. And, an infrared ray detector 62 is provided at a position where the infrared rays, which have transmitted through the sample S and the sampling plate 47, are to be received. In addition, reference numeral 63 designates an amplifier. An operation in this preferred embodiment, so that its detailed description is omitted. The present invention is not limited by the above described preferred embodiments and a differential refractometer may be used in place of the ultraviolet ray detector 37 in FIGS. 26 and 33. In addition, a spectrometric element may be used in place of the filter 53. And, although the pinholes 49 are formed as the condensing nuclei of the solution L deposited drop by drop on the thin film 48 made of the fluoride resins in the above described preferred embodiment, the thin film 48 made of the fluoride resins may be irradiated with laser beams or ultraviolet rays at appointed places thereof to reduced very small zones in surface tension. Furthermore, in the case where the sample S is irradiated with infrared rays in the micro spectrometric analyzers 41, 61, said infrared rays all over the bands may be irradiated to investigate the absorbing degree at the specified wavelength band, or, the infrared rays of the specified wavelength band may be irradiated to investigate a change of intensity thereof. For example, said change of absorbing intensity at the specified wavelength (for example an absorption band due to an expansion and contraction of C-H of 3,100 to 2,900 cm -1 and an absorption band due to a variable angle oscillation or an inverted symmetrical variable angle oscillation of C-H of 1,300 to 1,500 cm -1 exhibit a remarkably increased absorbing intensity) is measured, so that the analysis can be achieved in high sensitivity. As above described, according to the method of detecting organic compounds according to the present invention, an existence and concentrations of organic compounds, which have not been able to detect by the conventional methods, can be detected. That is to say, a detection limit in the conventional methods was 1×10 -6 g but that in the method according to the present invention was improved to 10×10 -12 g. Besides, the apparatus according to the present invention, the exclusive FTIR is not used differently from the conventional methods, so that the apparatus is simplified in construction and inexpensive. By the way, in the preferred embodiments shown in FIGS. 26 and 33, the liquid eluted from the column 36 was divided into the ultraviolet ray detector 37 and the micro spectrometric analyzer 41 at the suitable shunting ratio in the device for making a liquid branch 38. FIG. 35 is a diagram showing one example of the device for making a liquid branch 38. Referring to FIG. 35, reference numeral 71 designates a T-type branching joint provided with a passage 73 (connected with a passage connected with the column of the liquid chromatograph on the upstream side thereof), through which a liquid to be shunted flows upward from below, connected with a connecting portion 72 extending downward therefrom and a shunting passage 76, 77 connected with a right and left connecting portion 74,75, respectively, meeting at right angeles with said connection portion 72. In this preferred embodiment, a flexible tube made of fluoride resins (Teflon made by DuPont) is used as said shunting passages 76, 77. In order to more concretely describe it, said construction shown in FIG. 35 is illustrated in FIG. 34. That is to say, referring to FIG. 34, C designates a junction and S, E designates said outlet end of the tube 76, 77, respectively. And, said height of the outlet end S, E of each tube 76, 77 is relatively changed by moving said outlet end E (or S) of the tube 77 (or 76) downward along a semicircle shown by an imaginary line under the condition that the outlet end S (or E) of the other tube 76 (or 77) is held at the same height as said junction C, in short the tube 76 (or 77) is held horizontally. Now, provided that a difference between the outlet end E and the junction C as the standard when the outlet end E was lowered to a position shown by a mark E' in height is+ΔH, a difference between the outlet end S and the junction C as the standard when the outlet end S was lowered to a position shown by a mark S' in height being-ΔH, both the tubes 76, 77 having a nominal outside diameter of 1.5 mm, the tube 76 having a nominal inside diameter of 0.25 mm, the tube 77 having a nominal inside diameter of 0.5 mm, and their lengths, in short a distance between C and S and a distance between C and E, being for example 300 mm equal to each other. The flow rate of liquid flowing on the side of the outlet end S and side of the outlet end E, respectively, when a position of the outlet end S or the outlet end E of the tube 76 or 77 was changed (lowered) in the above described manner is shown in the following Tables 2 and 3. TABLE 2______________________________________DifferenceΔH Flow rate of Flow rate of(mm) liquid on liquid onS = 0 the side of the side of Shunting0 - E' = + S E ratioΔH (ml/min) (ml/min) (S/E)______________________________________ 0 3.55 18.75 0.17820 3.0 18.9 0.15340 2.55 18.7 0.13760 2.2 18.9 0.11680 1.55 17.6 0.088100 1.25 18.0 0.069120 1.09 19.1 0.057140 0.89 20.2 0.044______________________________________ TABLE 3______________________________________DifferenceΔH Flow rate of Flow rate of(mm) liquid on liquid onS = 0 the side of the side of Shunting0 - S' = - S E ratioΔH (ml/min) (ml/min) (S/E)______________________________________ 0 3.55 18.75 0.17820 3.5 16.6 0.21040 4.15 16.9 0.24560 4.35 16.4 0.26580 4.5 15.3 0.294100 5.0 15.8 0.316120 5.15 15.4 0.334140 5.45 15.15 0.359______________________________________ That is to say, Table 2 shows the change of the flow rate of liquid on the side of the outlet end S and the side of the outlet end E, respectively, when the outlet end S is held at the same height as the junction C and the outlet end E was lowered by 20 mm in FIG. 34, while Table 3 shows the change of the flow rate of liquid on the side of the outlet end S and the side of the outlet end E, respectively, when the outlet E is held at the same height as the junction C and the outlet end S was lowered by 20 mm in FIG. 34. In addition, the flow rate of liquid to the junction C at this time was integrated for 20 minutes at 1 ml/min. And, in Tables 2 and 3, the shunting ratio represents a ratio of the flow rate of liquid flowing on the side of S to that flowing on the side of E. When ΔH=0, the tubes 76, 77 are held at the heights equal to each other, so that no difference is produced between the outlet end S and the outlet end E in height and thus the shunting ratio S/E amounts to a value corresponding to a ratio of a sectional area of the tube 76 to that of the tube 77 but it can be expressed by the following function (1) by the difference ΔH between the outlet end S and the outlet end E in height (until the vicinity of ΔH=100). That is to say, S/E-K·(ΔH)=sectional area of the outlet end S/sectional area of the outlet end E--(1) wherein K represents a constant determined according to the liquid. FIG. 36 is a graph showing a change of shunting ration S/E. Referring to FIG. 36, a curve A shown by a full line shows the change of shunting ratio S/E when an eluting liquid (comprising normal hexane and methanol) used in the liquid chromatography was shunted while a curve B shown by a dotted line shows the change of shunting ratio S/E when water was shunted. It is found from FIG. 36 that is case of said eluting liquid comprising normal hexane and methanol, the shunting ratio S/E can be continuously all over about one figure from 0.044 to 0.359 with 0.178 as a center. In addition, in case of water, the effect was reduced as compared with said case of the eluting liquid. FIG. 37 is a graph showing the change of shunting ratio S/E when the eluting liquid was shunted in the same manner as above described by the use of two pieces of tube (equal to each other in length) having the same inside diameter. As above described, according to the above described preferred embodiment, that ratio of the flow rate of liquid flowing through the tube 76 to that flowing through the tube 77 can be optionally and continuously changed by merely relatively changing the heights of the respective outlet ends of the tubes 76, 77. And, no flow rate-controlling instrument, such as needle value, is used, so that the eluting liquid is not made turbulent in current at all and thus no expansion is produced in the chromatogram and no difficulty in keeping the resolution power is observed. Although the above described preferred embodiment has such the construction that the liquid to be divided flows from below toward the junction C, the direction of the liquid flowing toward the junction C is optionally selected. And, it goes without saying that the branching passages 76, 77 may be formed of a pipe made of materials other than the above described Teflon. In addition, the method according to the present invention can be applied also to the case where the eluting liquid used in the liquid used in the liquid chromatograph is introduced into a mass analyzer. As above described, according to the present invention, in the case where the liquid flowing through one passage is shunted into two passages at the junction, the ratio of the flow rate of liquid flowing one passage to that flowing the other passage can be optionally and continuously changed by merely relatively changing the heights of the respective outlet ends of two branched passages, in particular a small flow rate of liquid, such as the eluting liquid of the liquid chromatograph, can be divided sampled at an optional ratio.

Microanalytical methods and associated apparatus for detecting and quantifying organic compounds with very high sensitivity utilize reflected or refracted infrared radiation. By depositing microliter sized quantities of the sample containing solution in a drop-by-drop manner on a water-repellent thin film and rapidly evaporating a solvent, a coherently condensed concentric sample is produced having enhanced sample thickness. This sample is irradiated with infrared radiation which is either reflected or transmitted by the material underlying the thin film. Measuring the spectrum of the infrared radiation passing through the sample detects the existence and concentration of the organic compound. The water-repellent thin film may be provided with multiple small scale depressions, pinholes or zones of reduced surface tension for condensing the sample.

BACKGROUND [0001] The applicant's prior published patent application GB2,494,435A discloses a communication system which utilises a guiding medium which is suitable for sustaining electromagnetic surface waves. The contents of GB2,494,435A are hereby incorporated by reference. The present application presents various applications and improvements to the system disclosed in GB2,494,435A. BRIEF SUMMARY [0002] In a first aspect, the present invention provides a communications system, comprising: a surface wave channel for guiding electromagnetic surface waves; a transmitter, coupled to said surface wave channel for transmitting signals along said surface wave channel; one or more disrupters, arranged to be positioned at arbitrary locations on or adjacent said surface wave channel, and arranged to convert said surface wave signals to space wave signals; and one or more receiver terminals, arranged to be positioned at locations corresponding to said disrupters, each terminal comprising an antenna for receiving said space wave signals. [0003] In a second aspect, the present invention provides a surface wave to space wave converter, comprising: a surface wave collector; and an antenna; wherein the surface wave collector is coupled to the antenna; the surface wave collector is arranged to collect surface wave signals from a surface wave channel; and the antenna is arranged to radiate said signal as a space wave. [0004] Further examples of features of the present invention are recited in the claims. DESCRIPTION OF THE DRAWINGS [0005] Embodiments of the present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which: [0006] FIG. 1 shows a communications system in accordance with an embodiment of the present invention; [0007] FIG. 2 shows a surface wave launcher for use with the system of FIG. 1 ; [0008] FIG. 3 shows further details of the surface wave launcher of FIG. 2 ; and [0009] FIG. 4 shows a surface wave to space wave converter in accordance with an embodiment of the present invention. DETAILED DESCRIPTION [0010] FIG. 1 shows a communications system 100 in accordance with an embodiment of the present invention. The system 100 includes a surface wave channel 101 . The surface wave channel may take the form of the surface wave channels disclosed in the applicant's published UK patent application, GB2,494,435A. In particular, the surface wave channel has a high surface impedance, and is suitable for guiding electromagnetic surface waves. The channel 101 is elongate, and is generally arranged to guide surface waves in the direction of its length. The channel may be made of a dielectric coated conductor, corrugated surface, or any other material which has a high surface impedance suitable for the transmission of electromagnetic surface waves. [0011] The system 100 further comprises a surface wave launcher 102 . The surface wave launcher 102 is arranged to convert electrical signals to surface wave signals. Further details of a suitable launcher are provided in GB2,494,435A, and are also described below. The system 100 also includes a server 103 . The server 103 is coupled to the surface wave launcher 102 by connection 104 . The server 103 is includes a transmitter, and is arranged to transmit data along the surface wave channel 101 . The surface wave launcher 102 converts signals received from the server 103 to surface wave signals. [0012] The system 100 also includes a plurality of disrupters 105 A, 105 B, 105 C. The disrupters may be positioned at arbitrary positions along the surface wave channel. The disrupters are arranged to disrupt the surface wave signals, and to cause the surface wave signals to be scattered as space waves. In the present embodiment, the disrupters 105 A, 105 B, 105 C are metallic plates, which act as reflectors. The metallic plates are positioned on the surface wave channel so that they are perpendicular to the surface. They are orientated to cause specular scattering at an angle of ninety degrees to the direction of the channel. In order to achieve this, the plates are orientated at a forty five degree angle. In use, when a surface wave hits the plate, it is reflected as a space wave. The reflectors may be arranged to reflect the surface waves towards the edge of the channel 101 , where they reradiate as space waves. Alternatively, the reflectors may be arranged to reflect the surface waves upwards, away from the surface. [0013] The system 100 also includes a plurality of user terminals 106 A, 106 B, 106 C. Each user terminal is coupled to an antenna 107 A, 107 B, 107 C. The antennas are arranged to receive the space waves reflected from the disrupters 105 A, 105 B, 105 C. As such, in use, the antennas and their corresponding user terminals are positioned in close proximity to the positions of the corresponding disrupters. In particular, the antennas 107 A, 107 B, 107 C are positioned close enough to the disrupters so that they may adequately receive the space wave signals. [0014] The user terminals 106 A, 106 B, 106 C may include a user interface which may include a display. The terminals may therefore be arranged to display data sent by the server 103 . One application of this system may be in a television broadcast system. For example, the system may be used as an in-flight entertainment system on a passenger airplane. [0015] In use, the server 103 broadcasts a data signal which may include multimedia data to be viewed by the user terminals 106 A, 106 B, 106 C. The signal is converted to a surface wave by surface wave launcher 102 . The surface wave propagates along the surface wave channel 101 . The disrupters 105 A, 105 B, 105 C are positioned such that only some of the surface wave is reflected, the remainder propagating along the surface channel towards the other disrupters. The reflected surface wave propagates as a space wave towards a corresponding antenna 107 A, 107 B, 107 C. The space wave is then converted to an electrical signal by the corresponding antenna. The converted signal is then received by the corresponding user terminal 106 A, 106 B, 106 C. [0016] FIG. 2 shows an example of a surface wave launcher which may be used with the system 100 shown in FIG. 1 . FIG. 2 shows a surface wave launcher 200 in accordance with a first embodiment of the present invention. The surface wave launcher includes a parallel-plate waveguide 201 and a feed section 202 . The waveguide 201 includes a feed end 203 and a launch end 204 . The feed section 202 is coupled to the waveguide 201 as the feed end 203 . The feed section includes a coaxial cable 205 . The coaxial cable includes an inner conductor 206 , an insulating layer 207 and an outer conductor 208 . The feed section 202 also includes a coupling pin 209 which is connected to the inner conductor 206 at an end of the coaxial cable. [0017] The waveguide 201 is a rectangular cuboid. The waveguide 201 includes a first planar conductor 210 , which is forms an upper surface of the waveguide. The first planar conductor 210 forms an isosceles triangle, the top vertex of which is connected to the coupling pin 209 . The waveguide 201 also includes a dielectric layer 211 , positioned below the first planar conductor 210 , and which is also a rectangular cuboid. The dielectric 211 is preferably low loss for the frequency of operation. The waveguide 201 also includes a second planar conductor (not shown in FIG. 2 ), which is positioned behind the dielectric layer 211 . The second planar conductor is rectangular in shape, and completely covers the underside of the dielectric 211 . [0018] FIG. 3 shows a cross-section through launcher 200 . The features of the launcher 200 are labelled in the same manner as in FIG. 2 . In FIG. 3 , the second planar conductor 212 is shown. The outer conductor 208 of the coaxial cable 205 is coupled to the second planar conductor 212 . [0019] FIG. 3 also shows a guiding medium 213 with which the surface wave launcher 200 is arranged to operate. The guiding medium may be similar to that described in the applicant's previously published UK patent application GB2,494,435A. The guiding medium 213 includes a dielectric layer 214 and a conductive layer 215 . Together they form a dielectric coated conductor with a reactive impedance which is higher than the resistive impedance. Such a surface is suitable for the propagation of electromagnetic surface waves. In use, the launcher 200 can be placed at a shallow angle to the surface of a guiding medium 213 to launch waves in a particular direction. The performance of the launcher 200 at a particular frequency can be optimised by changing the length of the triangle. [0020] The surface wave launcher 200 may also operate in reverse, as a surface wave collector. Furthermore, the system 100 may operate in reverse, with user terminals transmitting signals which are reflected by the disrupters onto the surface wave channel, to generate surface waves. [0021] As noted, above the system 100 includes a number of disrupters. FIG. 4 shows a surface wave to space wave converter 300 in accordance with an alternative embodiment of the present invention. The converter 300 includes a surface wave collector 301 and an antenna 302 . An output of the surface wave collector 301 is coupled to an input of the antenna 302 . The collector 301 may take the form of the surface wave launcher described above in connection with FIGS. 2 and 3 . As noted there, the surface wave launcher may operate in reverse as a surface wave collector. In use, the waveguide of the surface wave collector is positioned against the surface wave channel 101 . The collector 301 collects surface waves and converts them to electrical signals which are sent to the antenna 302 . The antenna 302 then radiates a corresponding space wave which may be received by a user terminal. The antenna 302 may take many forms. For example, it can be directional or omni-directional depending on the requirements of the system. [0022] In an alternative embodiment of the present invention, the converter 300 may be used to transmit a space wave signal to another converter, which then launchers a surface wave onto a further surface wave channel. This embodiment could be used where it is not possible to lay a surface wave channel, for example where a gap needs bridging. [0023] In the above-described embodiments, surface wave launchers and surface wave collectors have been described. These devices may in fact identical in construction. However, in use, the device will either act to “collect” surface waves, or to “launch” surface waves. The terminology used above has been selected dependent on the context in which the device is being used. It will be appreciated that in some contexts, the devices may be used for both purposes, even though they are referred to as either collectors or launchers. [0024] Features of the present invention are defined in the appended claims. While particular combinations of features have been presented in the claims, it will be appreciated that other combinations, such as those provided above, may be used. [0025] Further modifications and variations of the aforementioned systems and methods may be implemented within the scope of the appended claims.

A communications system, comprising: a surface wave channel for guiding electromagnetic surface waves; a transmitter, coupled to said surface wave channel for transmitting signals along said surface wave channel; one or more disrupters, arranged to be positioned at arbitrary locations on or adjacent said surface wave channel, and arranged to convert said surface wave signals to space wave signals; and one or more receiver terminals, arranged to be positioned at locations corresponding to said disrupters, each terminal comprising an antenna for receiving said space wave signals.

TECHNICAL FIELD The present invention relates to a radio communication terminal apparatus, radio communication base station apparatus, and radio communication method. BACKGROUND ART In a cellular communication system represented by, for example, 3GPP LTE (3rd Generation Partnership Project Long Term Evolution), a mobile station (hereinafter “UE” (user equipment)) is required to perform measurement process in order to perform mobility control such as a handover. This measurement includes intra-frequency measurement, inter-frequency measurement using gaps and inter-system measurement, and a cellular communication system is required to support these measurements. Also, inter-frequency measurement using gaps and inter-system measurement are also referred to as gap-assisted measurement. To perform gap-assisted measurement, UE is required to receive a signal from another cell with different carrier frequency or from another system, so that UE has to adjust its receiver away from the frequency of the source cell to another carrier frequency or another system of a neighbor cell. For UE to measure a neighbor cell, it is necessary to provide gaps (hereinafter also referred to as “an idle period”) to UE. In order to achieve gap synchronization between a serving base station and UE, explicit start position to activate gaps is configured. Also, gaps are arranged on a periodic basis, and these periodic gaps are referred to as a gap pattern. To perform measurement, this gap pattern needs to be provided over a long period. Therefore, by performing gap-assisted measurement base on the gap pattern arrangement, UE can support mobility control to other carrier frequencies or other systems even during communication. In addition, even during discontinuous reception (DRX), measurement is possible only after gap is activated. In addition to the above measurement process, gaps are used to receive broadcast information (also referred to as “system information”) of a specific cell. Specifically, gaps are also used to identify whether or not it is possible to access the cell called closed subscriber group (CSG) cell where only specific UE can access, by comparing the CSG identifier of this cell that is included in broadcast information and an accessible CSG identifier list that UE has. Since UE cannot receive broadcast information from other cells during communication with a serving base station, UE acquires broadcast information of other cells using gaps. Meanwhile, by explicit signaling is used to indicate the start of a gap pattern, a delay is expected until UE starts measurement. This is because there are a delay for decision to generate gaps in a base station, and a delay for signaling transmission to indicate the start of a gap pattern. Therefore, conventionally, the method to measure using DRX without designating gaps by explicit signaling, and the method to start measurement based on a CQI value measured without designating gaps by explicit signaling disclosed in non-patent literature 1 have been considered. In the former method, it is not necessary to provide an explicit gap pattern, so that it enables UE to start measurement earlier. In the latter method, as disclosed in non-patent literature 1, if the CQI value is lower than the defined threshold or the configured threshold, UE voluntary starts measurement step of using gap. A base station receives CQI reporting that implicitly shows that UE starts measurement and by this means can detect that UE starts measurement. CITATION LIST Non-Patent Literature NPL 1 R2-061922, 3GPP RAN2 document SUMMARY OF INVENTION Technical Problem However, since a DRX sleep period that is a time slot that can be used for measurement is not fixed, the former method cannot guarantee enough time slot for UE to perform measurement. This is because the DRX active period that is a time slot for UE to receive data may be extended, while UE can decode PDCCH properly. Therefore, due to the extension of DRX active period, the DRX sleep period has to be shortened. Thus, since the time that UE measures within the designated DRX sleep period lessens, it is required to extend the measurement until sufficient slots are acquired. As a result, it takes time to perform a handover. Meanwhile, in the latter method, the channel quality of UE changes dynamically, so that it is not possible to guarantee a sufficient time slot for UE to perform measurement. Specifically, when UE measures using a long gap pattern, the reported CQI values may suddenly change significantly, and it results in ending or suspending the measurement on the way. By this means, the complexity of UE configuration increases. It is therefore an object of the present invention to provide a radio communication terminal apparatus, radio communication base station apparatus and radio communication method that shorten the time required to perform handover without increasing constitutional complexity of a radio communication terminal apparatus. Solution to Problem The radio communication terminal apparatus of the present invention employs a configuration having: a gap verification section that decides whether to start a gap pattern in the current discontinuous reception cycle or to start the gap pattern in the next discontinuous reception cycle, based on a discontinuous reception active period to receive data and the length of an offset that shows the time from a start of the discontinuous reception active period to a start of the gap pattern; and a gap pattern configuration section that generates the gap pattern in the designated discontinuous reception cycle. A radio communication method employs a configuration having: a gap verification step of deciding whether to start a gap pattern in the current discontinuous reception cycle or to start the gap pattern in the next discontinuous reception cycle, based on a discontinuous reception active period to receive data and the length of an offset that shows the time from a start of the discontinuous reception active period to a start of the gap pattern; and a gap pattern configuration step where a radio communication terminal apparatus generates the gap pattern in the designated discontinuous reception cycle. Advantageous Effects of Invention The present invention can shorten the time for a handover without increasing constitutional complexity of a radio communication terminal apparatus. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a block diagram showing a configuration of UE according to embodiment 1 of the present invention; FIG. 2 is a block diagram showing a configuration of the base station according to embodiment 1 of the present invention; FIG. 3 shows a signaling flow of UE shown in FIG. 1 and a base station shown in FIG. 2 ; FIG. 4 is a flow diagram showing operation of UE shown in FIG. 1 ; FIG. 5 is a block diagram showing a configuration of UE according to embodiment 2 of the present invention; FIG. 6 is a flow diagram showing operation that UE shown in FIG. 5 determines gap information parameters; FIG. 7 shows a signaling flow of UE shown in FIG. 5 and the base station shown in FIG. 2 ; FIG. 8 is a block diagram showing a configuration of UE according to embodiment 3 of the present invention; FIG. 9A shows a signaling flow of UE shown in FIG. 8 and the base station shown in FIG. 2 ; FIG. 9B shows a signaling flow of UE shown in FIG. 8 and the base station shown in FIG. 2 ; FIG. 10 is a flow diagram showing a method for UE shown in FIG. 8 to determine UE-oriented GP information parameters; FIG. 11 is a flow diagram showing a method for UE shown in FIG. 8 to use UE-oriented GP; FIG. 12 is a block diagram showing a configuration of UE according to embodiment 4 of the present invention; FIG. 13 shows a signaling flow of UE shown in FIG. 12 and the base station shown in FIG. 2 ; FIG. 14 is a flow diagram shows operation of a gap adjusted verification section shown in FIG. 12 ; FIG. 15 is a block diagram showing a configuration of UE according to embodiment 5 of the present invention; FIG. 16 shows a signaling flow of UE shown in FIG. 15 and the base station shown in FIG. 2 ; FIG. 17 is a flow diagram showing operation of a measurement and gap information generating section shown in FIG. 15 ; FIG. 18 is a block diagram showing a configuration of UE according to embodiment 6 of the present invention; FIG. 19 is a flow diagram shows operation of UE shown in FIG. 18 ; FIG. 20 shows a signaling flow of UE shown in FIG. 18 ; and FIG. 21 shows operation of receiving SIB 1 . DESCRIPTION OF EMBODIMENTS Embodiments of the present invention will be described in detail with reference of the accompanying drawings. Here, in embodiments, the configurations having the same functions will be assigned the same reference numerals and their explanations will be omitted. (Embodiment 1) FIG. 1 is a block diagram showing a configuration of UE 100 according to embodiment 1 of the present invention. In this diagram, receiving section 101 can receive measurement configuration information and gap pattern configuration information via dedicated control signaling from the network. Measurement configuration information that is included in a RRC connection reconfiguration message as defined in 3GPP TS 36.331 is an example of such signaling. Once receiving these configuration information, receiving section 101 outputs the measurement configuration information to measurement section 102 and outputs the configured gap pattern parameters to gap pattern configuration section 104 . Here, as measurement configuration information, there are, for example, a measurement ID that is an identifier to manage measurement configuration, a measurement object that shows a system, frequency, cells, and so on of a measurement target, and a reporting configuration that defines, for example, an event to report the measurement. As gap pattern configuration information, there are, for example, UE-oriented GP start offset to define the position to start gaps, in addition to the gap pattern information (gap length and gap cycle) for measuring other systems and other carrier frequencies. After receiving measurement configuration information output from receiving section 101 , measurement section 102 stores the acquired measurement configuration information and at the same time starts measurement, based on the input physical layer reference signal (hereinafter simply referred to as “reference signal”). When the measurement configuration information stored in measurement section 102 includes both configuration information of serving carrier frequency and other carrier frequencies (that is, measurement configuration of intra-frequency and inter-frequency defined in 3GPP TS 36.331), measurement section 102 measures based on the input reference signal. Measurement section 102 can perform a cell search step and a measurement step of serving carrier frequency. When the event for serving carrier frequency measurement, that is for the purpose of reporting, is triggered, measurement section 102 outputs the result to measure serving carrier frequency to measurement report generating section 103 . “The quality of serving carrier frequency is lower than a specific threshold” and “a CSG cell is detected, so that this requires to receive broadcast information of a CSG cell” and so on are examples of the event here. Measurement report generating section 103 includes the measuring result output from measurement section 102 in a reporting message and transmits the reporting message to the base station. This reporting message may be referred to as a measurement report or intra-frequency measurement report. When a measurement report is transmitted from UE 100 to the base station properly, measurement report generating section 103 outputs a reporting success notice signal to gap verification section 105 . Gap pattern configuration section 104 stores gap pattern parameters output from receiving section 101 and at the same time outputs the gap pattern parameters to gap verification section 105 . It is possible for the gap pattern parameters to be a different form according to operations and configurations of network. As gap pattern parameters, there is UE-oriented gap pattern start offset (hereinafter, “UE-oriented GP”) (also referred to as UE-oriented GP start position, UE-oriented GP offset, UE-oriented GP position, or UE-oriented GP activation time) that indicates the time from the start of a DRX active period to the start of UE-oriented GP. Gap verification section 105 decides the position to activate UE-oriented GP, based on gap pattern parameters output from gap pattern configuration section 104 and a reporting success notice signal output from measurement report generating section 103 . This starting position is for UE 100 to start gap to perform measurement Gap verification section 105 decides the position to activate UE-oriented GP, based on a relationship between a DRX active period and UE-oriented GP start offset. UE 100 decides the starting point of UE-oriented GP start offset, based on the starting point of DRX cycle where a measurement report has been properly transmitted to base station 200 (one DRX cycle is formed by one DRX active period and one DRX sleep period following this DRX active period). At the time to transmit the measurement report, UE 100 verifies whether or not the extended DRX active period will end before UE-oriented GP start offset. UE 100 performs the following operation, according to whether or not the extended DRX active period will end before UE-oriented GP start offset. (1) When the extended DRX active period ends before UE-oriented GP start offset, it is assumed that, in UE 100 , the DRX active period will not overlap with UE-oriented GP in the current DRX cycle. Thus, UE 100 activates UE-oriented GP in the current DRX cycle. (2) When the extended DRX active period ends after UE-oriented GP start offset, it is assumed that, in UE 100 , the DRX active period will overlap with UE-oriented GP in the current DRX cycle. Thus, UE 100 activates UE-oriented GP in the next DRX cycle. As above, gap verification section 105 decides the timing to activate UE-oriented GP and outputs the decided timing to UE-oriented GP configuration section 106 . UE-oriented GP configuration section 106 decides the position to start UE-oriented GP based on the timing output from gap verification section 105 , and generates a gap pattern according to the position. By this means, UE 100 can measure other carrier frequencies of neighbor cells or other systems by using UE-oriented GP. When event criteria of reporting about the measurement of the triggered other carrier frequencies are met, UE 100 transmits the measurement result to base station 200 via a measurement report. FIG. 2 is a block diagram showing a configuration of base station 200 according to embodiment 1 of the present invention. In this diagram, if it is determined that the measurement about other carrier frequencies or other systems is necessary in UE 100 , measurement configuration section 201 decides measurement parameters for inter-frequency measurement or inter-RAT measurement. These measurement parameters are output to dedicated signal generating section 203 . Gap pattern configuration section 202 decides UE-oriented GP start offset based on the configured idle period (that is, the DRX cycle). Since UE-oriented GP start offset is based on the currently provided DRX cycle, the length of UE-oriented GP start offset should not be longer than the provided DRX cycle. UE-oriented GP start offset aims to decide the position where UE 100 can start UE-oriented GP without overlapping with the DRX active period as a result. Gap pattern configuration section 202 outputs UE-oriented GP start offset to dedicated signal generating section 203 . Dedicated signal generating section 203 decides the provided UE-oriented GP start offset and specific UE 100 where measurement information is subject to send, and generates downlink dedicated signaling (which includes measurement configuration information and UE-oriented GP start offset) to this UE 100 . This signaling is output to transmitting section 204 and transmitted to UE 100 . An example of this downlink dedicated signaling is the measurement configuration information included in a RRC connection reconfiguration message defined in 3GPP TS 36.331. FIG. 3 shows signaling flow of UE 100 shown in FIG. 1 and base station 200 shown in FIG. 2 . At first, a base station configures gap pattern configuration information and measurement configuration information. A base station transmits these configuration information to UE 100 . UE 100 receives and processes the configuration information transmitted from base station 200 . When an idle period to measure other carrier frequencies is necessary, UE 100 decides UE-oriented GP configuration based on the gap pattern criteria. Measurement report generating section 103 generates this UE-oriented GP configuration information with a measurement result and transmits to base station 200 through uplink dedicated control signaling (hereinafter “measurement report”). After a measurement report is transmitted to base station 200 properly, UE-oriented GP starts using the provided gap pattern parameters (hereinafter “UE-oriented GP start offset”) in gap verification section 105 . Gap verification section 105 determines whether or not the activation of UE-oriented GP does not result in overlapping with the data resource arranged within the extended DRX active period. This determination is made by comparing the length of the extended DRX active period and the length of UE-oriented GP start offset. When a measurement report is transmitted properly and the extended DRX active period ends before the timing indicated by UE-oriented GP start offset, in UE 100 , data is considered not to overlap with the measurement, even if UE-oriented GP starts within the current DRX cycle after the timing indicated by UE-oriented GP start offset. Therefore, UE 100 can start the UE-oriented GP just before the DRX-On duration. When a measurement report is transmitted properly and the extended DRX active period ends after the timing indicated by UE-oriented GP start offset, in UE 100 , the DRX active period is possible to overlap with the measurement, even if UE-oriented GP starts after the timing indicated by UE-oriented GP start offset. Therefore, to prevent data and measurement from overlapping, UE 100 starts UE-oriented GP after the timing indicated by UE-oriented GP start offset in the next DRX cycle. To describe the above operation in detail, in the following example, the section for the UE-oriented GP start offset is based on the number of subframe and the service running in UE 100 is video streaming. In LTE, a single gap length is adopted for inter-frequency E-UTRA and inter-RAT (3GPP systems). Gap length=6 subframes; UE-oriented GP start offset=25 subframes; DRX cycle=40 subframes; DRX-On duration=10 subframes; DRX Inactivity timer=5 subframes; DRX starting time instant=5th subframe. If it is decided, based on the quality of UE 100 frequency, that it is necessary to measure other carrier frequencies or other system radio conditions, that is, if the quality of UE 100 frequency deteriorates and the event criteria of reporting are satisfied, UE 100 includes the evaluated measured result in a measurement report message and transmits to base station 200 . In the following example, it is assumed that the extended DRX active period ends and a measurement report has been transmitted already within the same DRX cycle. Extended DRX active period=DRX starting time instant+DRX-On duration+DRX Inactivity timer=5th+10+5=20th subframe. UE-oriented GP starting time instant=DRX starting time instant+UE-oriented GP start offset=5th+25=30th subframe. Since the extended DRX active period ends before the timing indicated by UE-oriented GP start offset, UE 100 activates UE-oriented GP within the current DRX cycle as illustrated. Remaining DRX cycle=DRX cycle−UE-oriented GP Activation=40−30=10 subframes. Thus, the remaining DRX cycle (10 subframes) is longer than gap length (6 subframes). Therefore, UE 100 can use UE-oriented GP in the current DRX cycle without overlapping the DRX active period and measurement as a result. The above method is one way to indicate how to communicate the information (for example, UE-oriented GP start offset) that is necessary between UE 100 and base station 200 , and as other methods, it is also possible to use signaling between base station 200 and UE 100 by radio resource control and medium access control (MAC). Next, the method to use UE-oriented GP start offset based on a trigger of a measurement report will be described using FIG. 4 . FIG. 4 is a flow diagram showing operation of UE 100 shown in FIG. 1 . In this diagram, in step (hereinafter abbreviated as “ST”) 301 , measurement report generating section 103 transmits a measurement report to base station 200 . In ST 302 , after measurement is performed properly, gap verification section 105 verifies whether or not the DRX active period overlaps in the case where a gap pattern starts, in checking steps of the DRX active period, using UE-oriented GP start offset. When the DRX active period overlaps with a gap pattern (YES), the step moves to ST 303 , and when the DRX active period does not overlap with a gap pattern (NO), the step moves to ST 304 . In step ST 303 , gap verification section 105 uses the start position of the next DRX cycle as a benchmark and decides the position to start a gap pattern using the length of UE-oriented GP start offset. In the next DRX cycle, UE 100 starts UE-oriented GP. In ST 304 , UE-oriented GP configuration section 106 starts UE-oriented GP, based on the gap length required for each measurement of, for example, inter-frequency E-UTRA, inter-RAT UTRAN, inter-RAT GERAN or inter-RAT CDMA 2000, and the gap repetition included in UE-oriented GP information parameters (which UE 100 decides based on the criteria for UE-oriented GP). According to embodiment 1, by starting UE-oriented GP in the current DRX cycle or starting in the next DRX cycle depending on the relationship of length between the extended DRX active period and UE-oriented GP start offset, it is possible to shorten the time required to perform a handover without increasing the constitutional complexity of a radio communication terminal apparatus. (Embodiment 2) FIG. 5 is a block diagram showing a configuration of UE 400 according to embodiment 2 of the present invention. FIG. 5 differs from FIG. 1 in that measurement report generating section 103 is changed to measurement and gap information generating section 401 . Measurement and gap information generating section 401 decides gap information parameters that is the information showing a gap pattern of the measurement using UE-oriented GP, and reports this parameter to a base station by using a reporting message (i.e. measurement report message, or other messages). The gap information parameters is decided based on the information available only in UE 400 , for example, the settings user provides respectively, the application running on the device, or the moving speed of the user. According to these criteria, UE 400 can decide a gap pattern used for the measurement using UE-oriented GP. Thus, UE 400 can provide freely the gap information parameters to decide the gap pattern. UE 400 transmits the measurement result to base station 200 by a reporting message. This reporting message is referred to as a measurement report, intra-frequency measurement report as defined in 3GPP TS 36.331. This reporting message is referred to as “measurement report” hereinafter. When a measurement report is transmitted properly from UE 400 to base station 200 , measurement and gap information generating section 401 outputs a reporting success notice signal to gap verification section 105 . By this means, UE 400 can assure gap pattern synchronization with base station 200 . Therefore, a data will not overlap with UE-oriented GP, so that a packet will not be lost. Next, the method for UE 400 to decide UE-oriented GP information parameters will be described using FIG. 6 . FIG. 6 is a flow diagram showing operation that UE 400 shown in FIG. 5 decides gap information parameters. In ST 501 , if it is necessary to measure other carrier frequencies, UE 400 starts a step to decide a gap pattern of the measurement using UE-oriented GP. As a reference, it is possible to use, for example, a fading signal that is an index of the moving speed of UE 400 and the instantaneous quality values of the current serving cell. Specifically, when the moving speed is fast or the quality of the current serving cell is poor, it is considered to be necessary to perform moving process fast, so that it is possible to, for example, measure other carrier frequencies or other systems. As other means, it is possible to change the frequency according to the number of the detected CSG cells. For example, it is possible to increase the frequency of gaps, when the number of the detected. CSG cell is large, since many gaps are required to receive broadcast information, or decrease the frequency of gaps to receive broadcast information, when the number of the detected CSG cell is small. In ST 502 , UE 400 decides the frequency of the measurement using UE-oriented GP. Specifically, by using UE-oriented GP, UE 400 decides the frequency of the measurement and determines whether or not the measurement frequency is high. When measurement frequency is identified as higher than the desired threshold (YES) by the mobile speed or the quality of serving cells as above, the step moves to ST 503 , and when measurement frequency is identified as lower than the desired threshold (NO), move to ST 504 . In ST 503 , UE 400 uses UE-oriented GP with a short cycle to increase measurement frequency that uses UE-oriented GP. Specifically, a short gap cycle is provided while the designated gap length remains as is. These provided gap information parameters (hereinafter also referred to as “UE-oriented GP information parameters”) include information, such as short gap cycle parameters and gap identification information parameters. In ST 504 , UE 400 uses UE-oriented GP with a long gap cycle to decrease measurement frequency that uses UE-oriented GP. Specifically, a long gap cycle is provided while the designated gap length parameters remains as is. UE-oriented GP information parameters include, for example, a long gap cycle parameters and gap identification information parameters. ST 505 generates UE-oriented GP information parameters and the measured result, and includes these in a measurement report to be sent to base station 200 . The purpose to include UE-oriented GP information parameters in a measurement report is to inform base station 200 that UE 400 starts measurement using UE-oriented GP that is based on the designated gap length and the gap cycle decided by UE 400 . Thus, by including UE-oriented GP information parameters in a measurement report, it is possible to synchronize UE-oriented GP between base station 200 and UE 400 . Next, an operation of UE 400 of using each criterion will be described. First, a case where a fading signal is adopted as criteria will be described. When a fading signal indicates that UE 400 moves fast, it is expected that the possibility of a handover (mobility) is high in UE 400 . Thus, a high measurement frequency is necessary. UE 400 provides a short cycle gap pattern and performs measurement more frequently. On the other hand, when a fading signal indicates that UE 400 moves slow, it is expected that the possibility of a handover is low in UE 400 . Thus, a low measurement frequency is possible. UE 400 provides a long cycle gap pattern and measures less frequently. Next, a case where the instantaneous quality value of the current serving cell is adopted as criteria will be described. When the instantaneous quality value deteriorates, it is expected that reception condition from base station 200 is poor in UE 400 . This implies a need for UE 400 to perform a handover mobility step in order to assure connectivity. Thus, a high measurement frequency is necessary, so that UE 400 provides a short cycle gap pattern. Meanwhile, when the instantaneous quality value ameliorates or is good, a need for UE 400 to perform a handover mobility step is less demand. Thus, it is possible to lower measurement frequency related to UE 400 mobility. UE 400 provides a long cycle gap pattern and performs measurement less frequently. FIG. 7 shows signaling flow of UE 400 shown in FIG. 5 and base station 200 shown in FIG. 2 . In this diagram, a case where gap pattern synchronization between UE 400 and base station 200 is assured will be described. Base station 200 provides gap pattern configuration information and measurement configuration information by using radio resource control (RRC). Base station 200 transmits these configuration information from transmitting section 204 to UE 400 . UE 400 receives messages transmitted from base station 200 and processes these configuration information. When an idle period is required to measure other carrier frequencies, UE 400 decides UE-oriented GP configuration based on gap pattern criteria. Measurement and gap information generating section 401 generates this UE-oriented GP configuration information and the evaluated measurement result, and transmits these to base station 200 via an uplink dedicated control signaling. After a measurement report that includes UE-oriented GP is transmitted properly to base station 200 , in gap verification section 105 , gap verification for UE-oriented GP start offset is performed by using the configured gap pattern parameters (UE-oriented GP start offset). When UE-oriented GP starts, gap verification section 105 determines whether or not the DRX active period and the gaps overlap. This determination is made by comparing the length of extended DRX active period and the length of UE-oriented GP start offset. Since this operation is the same as the content described in embodiment 1, the description will be omitted. UE does not decide a gap cycle freely, and it is equally possible for a base station to provide a guide line and report to UE. For example, in the case to decide a gap cycle based on the moving speed of UE, it is possible, for example, to report to UE a threshold of the moving speed of UE that decides whether the gap frequency is high or low. In this case, UE will decide a gap cycle according to a guideline indicated by a base station. In addition, it is also possible for a base station to report to UE an option of gap repetition. Specifically, for example, when more than three gap cycles are prepared under standardization, it is possible for a base station to report to UE which gap cycle to select. In 3GPP LTE which is currently standardized, two cycles, such as 40 ms and 80 ms, are defined. Thus, UE according to embodiment 2 only selects 40 ms or 80 ms. However, for example, 20 ms or 160 ms of gap cycles are possible to be added in future, so that, in that case, by narrowing down the options, it is possible to allow UE to make a choice that suits operation of a base station. According to embodiment 2, by controlling the measurement frequency using UE-oriented GP according to UE reception condition, it is possible to increase measurement frequency by using a short cycle UE-oriented GP and prepare for a handover, when UE has poor reception condition, or it is possible to decrease measurement frequency by using a long cycle UE-oriented GP and lower UE power consumption, when UE has good reception condition. (Embodiment 3) FIG. 8 is a block diagram showing a configuration of base station 600 according to embodiment 3 of the present invention. FIG. 8 differs from FIG. 1 in that gap pattern configuration section 104 is removed, measurement report generating section 103 replaces measurement and UE-oriented. GP information generating section 601 , and gap verification section 105 replaces UE-oriented GP verification section 602 . When the measurement reporting criteria are met, measurement and UE-oriented GP information generating section 601 generates each configuration information and includes the information in a measurement report. While measurement and UE-oriented GP information generating section 601 decides UE-oriented GP period parameter including the time required for CQI reporting from UE 600 , provides the decided UE-oriented GP period parameters, at the same time, measurement and UE-oriented GP information generating section 601 includes this configuration information in a measurement report and transmits to base station 200 . When a measurement report is transmitted within the extended DRX active period, the reporting notification is output to UE-oriented GP verification section 602 . UE-oriented GP verification section 602 verifies whether to activate UE-oriented GP in the current DRX cycle or in the next DRX cycle by using UE-oriented GP period parameters. Once the position to start UE-oriented GP is decided based on UE-oriented GP period parameters, UE-oriented GP verification section 602 provides UE-oriented GP. FIG. 9 shows signaling flow of UE 600 shown in FIG. 8 and base station 200 shown in FIG. 2 . FIG. 9 illustrates an example that UE 600 decides UE-oriented GP period parameters, and verifies whether to start UE-oriented GP in the current DRX cycle or in the next DRX cycle. UE 600 stores the measurement configuration information, and processes and measure in measurement section 102 . When the measurement reporting criteria are met, UE 600 decides UE-oriented GP period parameters based on the criteria to decide UE-oriented GP, and configures the gap information parameters. The criteria are based on the time required for measurement that is necessary to report channel quality indicator (CQI), and the gap length designated for measurement. Specifically, when the channel quality indicator is reported at the beginning subframe of DRX active, the criteria are the sum of the time required for measurement that is necessary to report channel quality indicator, and the gap length designated for measurement. When the channel quality indicator is reported at 2-subframe from the beginning of DRX active, the criteria are the value to subtract 1-subframe from the sum of the time required for measurement that is necessary to report channel quality indicator and the gap length designated for measurement. In this way, it is possible to decide UE-oriented GP period parameters by using the operation related to CQI reporting interval in UE 600 (for example, the position of CQI reporting in the DRX-On duration). When UE-oriented GP period parameters is decided, as defined in 3GPP TS 36.331, measurement and UE-oriented GP information generating section 601 includes UE-oriented GP information parameters and the measured results in a measurement report and transmits to base station 200 . When a measurement report which includes UE-oriented GP information parameters is transmitted, UE 600 adopts UE-oriented GP period parameters and verifies the DRX cycle where UE-oriented GP can start. UE-oriented GP verification section 602 activates UE-oriented GP just before the beginning of DRX-On duration based on the following conditions. Condition # 1 (see FIG. 9A ): (Configured DRX cycle—(DRX active period where a measurement report which includes UE-oriented GP information parameters is sent))>UE-oriented GP period. Condition # 2 (see FIG. 9B ): (Configured DRX cycle—(DRX active period where a measurement report which includes UE-oriented GP information parameters is sent))=<UE-oriented GP period. When a measurement report including UE-oriented GP information parameters is transmitted and the length of the extended DRX active period does not overlap with the length of UE-oriented GP period parameters when the starting point of the DRX-On duration from the next DRX cycle is defined as a reference, in UE 600 , the DRX active period does not overlap with the measurement when UE-oriented GP starts. Thus, as shown as condition #1 in FIG. 9A , UE 600 starts UE-oriented GP at the position where the remaining time within the current DRX cycle is equal to the length of UE-oriented GP period parameters. When a measurement report including UE-oriented GP information parameters is transmitted and the length of the extended DRX active period overlaps with the length of UE-oriented GP period parameters when the starting point of the DRX-On duration from the next DRX cycle is defined as a reference, in UE 600 , the DRX active period overlaps with the measurement when UE-oriented GP starts. Thus, as shown as condition #2 in FIG. 9B , UE 600 starts UE-oriented GP at the position where the remaining time within the next DRX cycle is equal to the length of UE-oriented GP period parameters. Next, the method for UE 600 shown in FIG. 8 to decide UE-oriented GP information parameters will be described using FIG. 10 . In FIG. 10 , the same components of FIG. 6 will be assigned the same reference numerals in FIG. 6 and their explanations will be omitted. In ST 701 , measurement and UE-oriented GP information generating section 601 decides repetition of UE-oriented GP based on a measurement requirement level, and outputs gap repetition configuration information to UE-oriented GP verification section 602 . UE-oriented GP verification section 602 decides UE-oriented GP period parameters based on criteria lists to select UE-oriented GP, and verifies the position to start UE-oriented GP. UE-oriented GP verification section 602 adopts the CQI reporting interval (for example, the position of CQI reporting of the DRX-On duration) in UE 600 and decides the length of UE-oriented GP period parameter. After deciding UE-oriented GP duration parameters, UE-oriented GP verification section 602 outputs the parameters and the gap repetition configuration information to measurement and UE-oriented GP information generating section 601 . UE 600 includes these configuration parameters in a measurement report and transmits to base station 200 . By including UE-oriented GP period parameters in a measurement report, it is possible to report to base station 200 the position where UE 600 starts UE-oriented GP. Next, based on a trigger of a measurement report, the method for UE 600 to use UE-oriented GP will be explained using FIG. 11 . FIG. 11 is a flow diagram showing the steps where UE 600 decides the position to start UE-oriented GP in the current DRX cycle or in the next DRX cycle. In FIG. 11 , the same components of FIG. 4 will be assigned the same reference numerals in FIG. 4 and their explanations will be omitted. In ST 801 , in the checking step of the DRX active period, UE-oriented GP verification section 602 adopts UE-oriented GP period parameters, verifies whether or not the DRX active period overlaps with gaps, and decides the position to start UE-oriented GP. When the DRX active period overlaps with UE-oriented. GP (YES), the step moves to ST 802 , and when the DRX active period does not overlap with UE-oriented GP (NO), the step moves to ST 304 . In ST 802 , as the starting position of UE-oriented GP, UE-oriented GP verification section 602 adopts the length of UE-oriented GP period parameters when the start point of the DRX-On duration in the next DRX cycle is defined as a reference. According to embodiment 3, by starting UE-oriented GP in the current DRX cycle or in the next DRX cycle depending on the relationship of length between UE-oriented GP period parameters that include the time required for CQI reporting from UE 600 and the extended DRX active period, it is possible to shorten the time required to perform a handover without increasing the constitutional complexity of a radio communication terminal apparatus. (Embodiment 4) FIG. 12 is a block diagram showing a configuration of UE 900 according to embodiment 4 of the present invention. FIG. 12 differs from FIG. 1 in that measurement report generating section 103 is changed to measurement and gap information generating section 901 , and gap verification section 105 is changed to gap adjusted verification section 902 . Measurement and gap information generating section 901 generates configuration information from the UE-oriented GP information parameters and the measurement result output from measurement section 102 , and includes in a measurement report. Measurement and gap information generating section 901 does not transmit a measurement report to base station 200 , and outputs this configuration information to gap adjusted verification section 902 . Gap adjusted verification section 902 starts UE-oriented GP based on lists of criteria. Once the criteria are met, gap adjusted verification section 902 adopts UE-oriented GP start offset that is stored in gap pattern configuration section 104 and starts UE-oriented GP. UE 900 evaluates whether to transmit a measurement report to base station 200 based on transmission criteria. When the transmission criteria are met, UE 900 provides UE-oriented GP information parameters and transmits to base station 200 via a measurement report. When the transmission criteria are not met, UE 900 does not transmit a measurement report to base station 200 as shown in FIG. 13 . Here, the transmission criteria are, for example, the presence or absence of other data to transmit and receive, and the length of DRX cycle. For example, if there is other data to transmit and receive, power consumption does not increase even when a measurement report is transmitted, and if there is no other data to transmit and receive, it is ideal not to transmit to reduce power consumption. Also, if DRX repetition is short, power consumption does not increase when a measurement report is transmitted, and if DRX repetition is long, it is preferable not to transmit a measurement report to reduce power consumption. According to the configuration above, even when using a service with a long DRX configuration, it is possible for UE 900 to activate measurement by using UE-oriented GP, whether or not a measurement report is transmitted. FIG. 13 shows signaling flow of UE 900 shown in FIG. 12 and base station 200 shown in FIG. 2 . FIG. 13 illustrates an example for UE 900 to establish a service of a long DRX configuration and start UE-oriented GP, whether a measurement report is transmit immediately or not. UE 900 stores the measurement configuration information, and processes and measure in measurement section 102 . When the criteria to start UE-oriented GP are met, UE 900 immediately starts measurement using the started UE-oriented GP. The criteria to start UE-oriented GP can be based on a threshold provided for radio quality of a serving cell. For example, when the radio quality of UE 900 serving cells drops below the threshold, UE 900 starts UE-oriented GP in the current DRX cycle. As base station 200 can synchronize gap pattern start with UE 900 for measurement, UE 900 determines whether or not it is necessary to provide UE-oriented GP information parameters and transmit to base station 200 via a measurement report as defined in 3GPP TS 36.331. Thus, whether or not UE 900 needs to transmit a measurement report can be determined based on 1) when UE 900 is required to resume downlink or uplink data; or 2) when the extended DRX active period of UE 900 is expected to overlap with UE-oriented GP. Furthermore, UE 900 transmits a measurement report by using random access step to transmit a measurement report, only when determining that the synchronization with base station 200 is necessary. FIG. 14 is a flow diagram showing operation of gap adjusted verification section 902 shown in FIG. 12 . In FIG. 14 , in ST 1001 , gap adjusted verification section 902 obtains UE-oriented GP information parameters and a measurement result, and, base on criteria of UE-oriented GP in a long DRX, determines whether or not UE 900 needs to start to measure other carrier frequencies using UE-oriented GP. It is possible to control UE-oriented GP in a long DRX based on a threshold configured for radio quality of serving cells. When the radio quality of serving cells drops below the threshold, UE 900 starts UE-oriented GP based on UE-oriented GP start offset. In ST 1002 , UE 900 determines whether or not there is an available uplink resource to transmit a measurement report to base station 200 . When an uplink resource is available (YES), the step moves to ST 1003 , and when an uplink resource is not available (NO), the step moves to ST 1004 . In ST 1003 , UE 900 transmits a measurement report including UE-oriented GP information parameters to base station 200 , and in ST 1004 , UE 900 starts UE-oriented GP. According to embodiment 4, by starting UE-oriented GP when a long DRX is provided, whether or not to transmit a measurement report, it is possible to shorten the time required to perform a handover without increasing the constitutional complexity of radio communication terminal apparatus. (Embodiment 5) FIG. 15 is a block diagram showing a configuration of UE 1100 according to embodiment 5 of the present invention. FIG. 15 differs from FIG. 1 in that measurement report generating section 103 is changed to measurement and gap information generating section 1101 . Measurement and gap information generating section 1101 decides the cycle of UE-oriented GP based on the measurement frequency. In addition, when different measurement type are configured by base station 200 , UE 1100 decides an adequate gap length corresponding to the configured measurement type. FIG. 16 shows signaling flow of UE 1100 shown in FIG. 15 and base station 200 shown in FIG. 2 . This diagram shows the signaling flow of when UE 1100 uses a plurality of gap lengths. In this embodiment, UE 1100 decides a measurement demand level and an individual gap length adopted for this measurement. This is because UE 1100 adopts different gap lengths corresponding to different measurements. Specifically, in the case of measurements of, for example, inter-frequency E-UTRA, inter-RAT UTRAN or inter-RAT GERAN, UE 1100 adopts a common gap length to perform measurement. For other measurements (for example, WiMAX), UE 1100 adopts a different gap length to perform measurement Thus, base on the configured measurement types, UE 1100 can decide an adequate gap length for the measurement using UE-oriented GP. Measurement section 102 of UE 1100 decides a gap length based on the configured information. Once deciding an adequate gap length, UE 1100 provides gap length parameters and includes this information in UE-oriented GP information parameters included in a measurement report. Thus, UE 1100 activates UE-oriented GP having an adequate gap length and adequate gap repetition, and transmits to base station 200 via a measurement report. As shown in FIG. 16 , when UE 1100 activates UE-oriented GP by using an adequate gap repetition and gap length, UE 1100 provides these gap related parameters in UE-oriented GP information parameters and transmits to base station 200 via a measurement report. By this means, it is possible to maintain and guarantee UE-oriented GP synchronization between base station 200 and UE 1100 . FIG. 17 is a flow diagram showing operation of measurement and gap information generating section 1101 shown in FIG. 15 . In FIG. 17 , the same components of FIG. 6 will be assigned the same reference numerals in FIG. 6 and their explanations will be omitted. In FIG. 17 , in ST 1201 , based on the configured measurement type provided by base station 200 , whether or not a short gap length is adequate for the gap length of UE-oriented GP is determined. When the measurement types, such as inter-frequency E-UTRA, inter-RAT UTRAN, inter-RAT GERAN or inter-RAT CDMA 2000 are provided and a short gap length is adequate (YES), the step moves to ST 1202 . Meanwhile, when the measurement type such as WiMAX is provided and a long gap length is adequate (NO), the step moves to ST 1203 . In ST 1202 , UE-oriented GP adopts a short gap length. In ST 1203 , UE-oriented GP adopts a long gap length. According to embodiment 5, even when the different time required to measure for each measurement type by deciding a gap length depending on a measurement type, it is possible to measure by using a gap length with an adequate length, so that it is possible to resolve excess and deficiency of a gap length with respect to the time required for measurement and to shorten the time required to perform a handover. It is equally possible to use ACK of HARQ (Hybrid Auto Repeat reQuest) to a reporting success notice signal according to the above embodiments. (Embodiment 6) Embodiment 6 of the present invention shows the method for UE to generate gaps in a different way from the above embodiments. FIG. 18 is a block diagram showing a configuration of UE 1300 according to embodiment 6 of the present invention. FIG. 18 differs from FIG. 1 in that measurement report generating section 103 is changed to measurement report generating section 1301 , and gap verification section 105 is changed to gap option selecting and deciding section 1302 . Measurement report generating section 1301 differs from measurement report generating section 103 in the points to remove a reporting success notice signal that is an input to measurement report generating section 103 , and to be a reporting performance notice signal as an input to gap option selecting and deciding section 1302 , instead of a reporting success notice signal. Gap option selecting and deciding section 1302 decides the position to start UE-oriented GP, based on gap pattern parameters output from gap pattern configuration section 104 and a reporting performance notice signal output from measurement report generating section 1301 . This starting position is the position to start gaps where UE 1300 performs measurement. Unlike gap verification section 105 , gap option selecting and deciding section 1302 decides the position to start UE-oriented GP by using UE-oriented GP generating timing that is provided in UE. In the present embodiment, this UE-oriented GP generating timing that is provided in LIE is included in the gap pattern parameters output from gap pattern configuration section 104 . Specifically, the UE-oriented GP generating timing is expressly shown with a system frame number (hereinafter “SFN”) or a subframe, and shown, for example, as from subframe 5 of SFN that is SFN mod 10=3. The control of a gap length and gap repetition is decided as in gap verification section 105 . FIG. 19 is a flow diagram showing operation of UE 1300 shown in FIG. 18 . In this diagram, in ST 1401 , the even where measurement report generating section 1301 transmits a measurement report to a base station is triggered. As a result, a reporting is also triggered. In ST 1402 , according to a reporting performance notice signal from measurement report generating section 1301 , gap option selecting and deciding section 1302 verifies whether or not UE-oriented GP generating timing is provided. When UE-oriented GP generating timing is provided (YES), the step moves to ST 1403 , and when UE-oriented GP generating timing is not provided (NO), since UE-oriented GP cannot be generated, the process ends. In ST 1403 , gap option selecting and deciding section 1302 decides the next UE-oriented GP generating timing as the position for UE-oriented GP. FIG. 20 shows a signaling flow of UE 1300 shown in FIG. 18 . At first, a base station provides gap pattern configuration information and measurement configuration information. A base station transmits these configuration information to UE 1300 . UE 1300 receives and processes the configuration information transmitted from a base station. Here, the different point from FIG. 3 is to receive UE-oriented GP generating timing as gap pattern configuration information. When an idle period to measure other carrier frequencies or to receive from other cells, UE 1300 decides UE-oriented GP from the UE-oriented GP generating timing received from a base station. UE 1300 also transmits a measurement report to a base station. In FIG. 20 , although UE-oriented GP is generated after transmitting a measurement report, it is equally possible for UE-oriented GP to start first. In the present embodiment, the transmission of a measurement report is not a prerequisite to generate UE-oriented GP. Thus, it is possible not to transmit a measurement report. As explained in embodiment 1, as the events for reporting, there are, for example, “the quality of serving carrier frequency is lower than a specific threshold” and “a CSG cell is detected, so that this requires to receive broadcast information of a CSG cell.” Especially, when “a CSG cell is detected, so that this requires to receive broadcast information of a CSG cell,” reporting is not performed first, but it is possible to receive broadcast information of a CSG cell, and perform a reporting after receiving, for example, the cell global identifier (CGI) of this CSG cell or the CSG identifier (CSG ID). This is because the information such as CGI or CSG ID is necessary to identify whether or not it is possible for UE to access to the CSG cell, or which cell is actually possible to access. Furthermore, when a number of CSG cells are provided, it is possible to generate a plurality of UE-oriented GPs, so that UE throughput degradation and service quality deterioration are possible. As a solution, although it is possible to limit the above UE-oriented GP generating timing, in this case there is a problem that it takes time until UE-oriented GP is performed after UE detects a CSG cell. Therefore, it is possible not to limit the UE-oriented GP generating timing, but to limit the frequency to use the UE-oriented GP generating timing. For example, even if the UE-oriented GP generating timing occurs ten times per second, it is possible to limit the usage up to two times, or not to allow the usage for 500 ms if the UE-oriented GP generating timing is used once. Therefore, as an operation to limit the frequency to use the UE-oriented GP generating timing, it is possible for a base station to instruct this configuration to UE, or to perform a preliminarily decided operation. To receive broadcast information from a CSG cell, it is possible to use a gap of 80 ms once. Therefore, a configuration that a gap length is 80 ms and no gap repetition is always used without notifying a gap length and gap repetition from a base station. When there is no instruction from a base station, an operation, for example, to use this configuration is possible. The reason that a gap of 80 ms is necessary is that, since CGI, broadcast information that includes CSG ID, and system information block type 1 (SIB1) are transmitted to 20 ms at one time, it is possible for UE which reception quality is not good to try to improve the quality by receiving and combining it four times. The above SIB1 receiving operation will be described in detail in FIG. 21 . When receiving broadcast information, master information block (MIB) is received at first. The position of MIB is decided as the first subframe in all radio frames (which is 10 ms interval and has 10 subframes). SFN is included in this MIB. SIB1 is transmitted at the sixth subframe of an even-numbered SFN. Thus, the transmitting timing of SIB1 will be found after receiving MIB. As mentioned above, since it may be necessary to receive and combine four times to receive SIB1 accurately, it is possible to provide a gap of 80 ms as shown in case 1 in FIG. 21 . By this means, operations such as receiving MIB, to detect the transmitting timing of SIB1, and then to receive SIB1 until it is received successfully. However, once MIB is received from a CSG cell, UE comes to see at which timing a CSG cell transmits SIB1. Therefore, as shown in case 2, it is possible to provide gaps only for necessary parts in a gap of 80 ms. In this case, in a place where there is no gap, UE can transmit and receive with a base station where UE is originally connected. Furthermore, as other operations, as shown in case 3, it is possible to finish gaps when the reception of SIB1 succeeds. FIG. 21 shows an example where SIB1 reception succeeds at the third time. An operation that combines case 2 and case 3 of FIG. 21 is also possible. Even if UE does not perform DRX, the present invention is possible to perform UE-oriented GP. This is because the position for UE to start UE-oriented GP is predictable for a base station regardless of an DRX operation. In order for a base station to decide whether or not UE performs UE-oriented GP, it is possible to use a measurement report transmitted from UE, as shown in embodiment 1. As a measurement report here, it is possible to be a measurement report message that is defined as an RRC message as described above, a MAC control message, or a message in layer 1 . Furthermore, as a message in layer 1 , for example, CQI reporting is possible. In the present embodiment, as shown in FIG. 20 , a case to transmit measurement control information for each UE, and to show the UE-oriented GP generating timing in the information has been explained. However, as other examples, the operations such as transmitting via broadcast information or deciding a rule in advance are possible. It is equally possible to decide the UE-oriented GP generating timing by using an identifier arranged for each UE. For example, in chapter 7 of TS36.304V8.5.0, User Equipment (UE) procedure in idle mode, the method to decide the timing for UE to receive paging by using an identifier called international mode subscriber identity (IMSI). When determining by using an identifier of UE in this way, even by using broadcasting information and a specific rule, it will be possible to designate a different place as the UE-oriented GP generating timing for each UE. As an identifier of UE to use, it is not limited to IMSI, and it is possible to use, for example, C-RNTI (Cell Radio Network Temporary Identifier) and S-TMSI (SAE Temporary Mobile Station Identifier). Furthermore, it is also possible to control on and off of the present operation for each UE or cell, when transmitting a configuration via broadcast information or deciding a rule in advance. Specifically, when controlling for each UE, it is possible to notify on or off by an individual message, and when controlling for each cell, it is possible to notify on or off by broadcast information. Furthermore, in the above embodiment, it is shown that a CSG cell is detected, but a plurality of forms are possible for this. Specifically, (1) when the physical cell identifier of a cell that is decided to be used for CSG is detected; (2) when the physical cell identifier of a cell that is decided to be used for CSG is detected, and the quality of this CSG cell is above a certain level or included within the above specific numbers; (3) when the physical cell identifier of a cell that is decided to be used for CSG is detected, and the physical cell identifier of the cell seems to be accessible for UE; (4) when from, for example, position information of UE, it is possible to assume that there is a CSG cell; and when combining (1)˜(4) are possible. Furthermore, to assume that there is a CSG cell from, for example, position information of UE is an operation where UE saves the position information at the time when UE connected to a CSG cell before, and when UE comes close around the area, UE identifies that there is an accessible CSG cell. Here, it is equally possible, for example, to use global positioning system (GPS) to generate position information, and to save other cells information that UE can receive. Furthermore, it is also possible for the UE-oriented GP generation shown in the present embodiment to be cancelled or extended due to for example, competition of other operations. For example, there is a scheduling method called semi-persistent scheduling, for a service to transmit on a regular basis at comparatively a small data rate as voice communication. This is the method to decide in advance at which timing UE transmits or receives and to perform transmission and reception at the timing. When this semi-persistent scheduling is provided in UE and the UE-oriented GP generation is performed, if both happens at the same time, it is necessary to prioritize one of these. In that case, for example, it is possible to prioritize the semi-persistent scheduling. Furthermore, as a method to solve a problem that the semi-persistent scheduling and UE-oriented GP generation collide, it is possible to set the semi-persistent scheduling at the timing when UE-oriented GP is not generated. It is possible to realize this, for example, by scheduling operation of a base station. In the present embodiment, although it has been described that it is possible not to transmit a measurement report, it is equally possible to decide whether or not to transmit a measurement report based on the delay to generate UE-oriented GP. Specifically, when it is possible to generate UE-oriented GP within a specific time, it is possible not to transmit a measurement report, and when it exceeds the specific time, it is possible to transmit a measurement report and to promote a base station to arrange gaps. As the specific time mentioned here, it is equally possible to de decided as the fixed value by a system, to notify by, for example, broadcast information, or to transmit to each UE for consideration of, for example, services that UE uses. It is possible to realize by combining the operations shown in each embodiment above. Specifically, it is possible to identify to transmit a measurement report shown in embodiment 6 by using transmitting criteria shown in embodiment 4. Each embodiment mentioned above explains an example when the present invention is performed by hardware, but the present invention can be implemented with software. Furthermore, each function block employed in the description of each of the aforementioned embodiments may typically be implemented as an LSI constituted by an integrated circuit. These may be individual chips or partially or totally contained on a single chip. “LSI” is adopted here but this may also be referred to as “IC,” “system LSI,” “super LSI,” or “ultra LSI” depending on differing extents of integration. Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. After LSI manufacture, utilization of an FPGA (Field Programmable Gate Array) or a reconfigurable processor where connections and settings of circuit cells in an LSI can be regenerated is also possible. Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. Application of biotechnology is also possible. The disclosures of Japanese Patent Application No. 2009-101958, filed on Apr. 20, 2009, and Japanese Patent Application No. 2009-149876, filed on Jun. 24, 2009, including the specifications, drawings and abstracts, are incorporated herein by reference in their entirety. Industrial Applicability It is possible to apply a radio communication terminal apparatus, radio communication base station apparatus, and radio communication method of the present invention to, for example, a mobile communication system. REFERENCE SIGNS LIST 101 RECEIVING SECTION 102 MEASUREMENT SECTION 103 , 1301 MEASUREMENT REPORT GENERATING SECTION 104 , 202 GAP PATTERN CONFIGURATION SECTION 105 GAP VERIFICATION SECTION 106 UE-ORIENTED GP CONFIGURATION SECTION 201 MEASUREMENT CONFIGURATION SECTION 203 DEDICATED SIGNAL GENERATING SECTION 204 TRANSMITTING SECTION 401 , 901 MEASUREMENT AND GAP INFORMATION GENERATING SECTION 601 MEASUREMENT AND UE-ORIENTED GP INFORMATION GENERATING SECTION 602 UE-ORIENTED GP VERIFICATION SECTION 902 GAP ADJUSTED VERIFICATION SECTION 1101 MEASUREMENT AND GAP INFORMATION GENERATING SECTION 1302 GAP OPTION SELECTING AND DECIDING SECTION

A wireless communication terminal apparatus and wireless communication method, wherein the time necessary for implementation of handover is reduced without increasing the complexity of the configuration of the wireless communication terminal apparatus. A gap confirmation unit ( 105 ) determines to start the UE-initiated GP at the current DRX cycle in cases when the extended DRX active period is shorter than the UE-initiated GP start offset, and determines to start the UE-initiated GP at the next DRX cycle in cases when the extended DRX active period is longer than the UE-initiated GP start offset. A UE-initiated GP configuration unit ( 106 ) generates a gap pattern at the determined DRX cycle.

CROSS REFERENCE TO RELATED PATENT U.S. Pat. No. 4,107,792. BACKGROUND OF THE INVENTION This invention relates to an apparatus for the discontinuous mixing of at least two materials, at least one of which is a liquid. More particularly, the invention relates to a mixing apparatus which includes a container and a mixer disposed therein, the mixer having a first rotor which is driveable at high speed through a shaft, and a second rotor which replaces a stator and is driven at a lower speed, both the first rotor and the stator having teeth which cooperate by being positioned on mutually concentric but axially separate circles and which move past one another on circles of different radii to define shearing slots. An apparatus of the type to which this invention relates and of which it is an improvement is described in U.S. Pat. No. 4,107,792. It is a particular feature of the mixing apparatus described in the aforementioned patent that the radially farther outward circle of teeth on the rotor is disposed outside of the radially outwardly located circle of teeth on a stator. It has been found in the arrangement of the rotor relative to the stator as described in the aforementioned patent that, when solids are dispersed in liquids, the dispersal time is reduced to one fifth of the time required when using previously known types of apparatus. The total amount of energy required for a mixing process is simultaneously reduced by 75 to 80 percent of the energy expenditure which would otherwise be required. By disposing the radially outwardly lying circle of teeth of the rotor externally of the radially outwardly lying circle of teeth of the stator, the individual material particles and drops of fluid acquire a high tangential acceleration due to contact with the radially outwardly lying teeth of the rotor after passing the radially outwardly lying shear slots. The high tangential acceleration leads to the formation of pronounced circular flow patterns which guide all the small particles and/or droplets more often into the rotor-stator system so that all the particles are subjected to very high hydrodynamic shear stresses. Many other advantages and favorable effects are derived from the disposition of stator and rotor as described in the aforementioned patent and these descriptions are incorporated in the present disclosure by reference. One of the advantages of the design according to the U.S. Pat. No. 4,107,792 is that cavitation phenomena develop in the shearing slots between the rotor and the stator. Advantageously also, the teeth of the rotor and the corresponding teeth of the stator have the same axial extent and are mounted parallel to each other. Preferably, the teeth on both rotor and stator are in the form of pins. The use of mixing apparatus in practice has shown that the dispersal of thixotropic materials in fluids is made more difficult because the above-mentioned well-defined circular fluid flows did not appear. In order to improve the mixing characteristics for thixotropic materials, it has been proposed in a prospectus entitled "Drais Planetary Kneader Mixers", published by Draiswerke GmbH, West Germany, to mount the radially most outwardly lying row of teeth on the stator and, in addition thereto, to provide supplementary mixing tools driven by planetary gears, each supplementary mixing tool being attached to one planetary gear of the planetary gear train. Furthermore, movable strippers are disposed in the vicinity of the interior wall of the container. The use of this planetary mixer which employs the combination of a movable scraper or stripper, together with the above-described principal mixer consisting of a rotor and stator, has shown that the mixing of thixotropic materials remains unsatisfactory. SUMMARY OF THE INVENTION It is thus a principal object of the present invention to provide an apparatus for mixing at least two materials with a decreased energy input and a reduction of the mixing time. It is an associated object of the present invention to provide a mixing apparatus in which the aforementioned advantages are obtained when at least one of the materials to be mixed is a thixotropic material. The foregoing object as well as others which are to become clear from the text below, is achieved according to the invention by virtue of the fact that the mixing apparatus is provided with a second rotating shaft coaxial with and rotating in the same sense as the principal rotating shaft carrying the first rotor, and wherein the secondary rotating shaft carries a unit which replaces the stator as well as a scraper located and moving in the vicinity of the interior wall of the mixing container. The unit, hereinbelow referred to as a second rotor rotates at a lower angular velocity than the conventional rotor, hereinbelow referred to as the first rotor. It has been found, surprisingly, in using the apparatus of the invention which includes, in addition to the first rotor and the second rotor, only scrapers rotating slowly in the vicinity of the interior wall of the container but does not include any supplementary mixing tools, that the forced mingling of the materials is optimized. A possible explanation for this fact is that the supplementary mixing tools, for example the aforementioned planetary mixing tools, may actually disturb and diminish the circular fluid flows generated by the rotor-rotor system, whereas these circular flows are enhanced when only scrapers are present. It should be noted that the construction according to the present invention is advantageous even when non-thixotropic materials are mixed and will lead to a substantial reduction of the mixture time because all of the particles and droplets of the materials to be mixed participate in the forced motion in a statistically more uniform manner so that each particle or droplet completes the required number of passages through the shearing slots of the rotor-rotor system substantially sooner. The second rotor of the present invention actually rotates but its speed of rotation is substantially slower than that of the first rotor and has consequently stator-like characteristics to a considerable degree. Advantageously, the second rotating shaft carrying the second rotor and the wall scraping attachment is a hollow shaft which coaxially surrounds the principal drive shaft of the first rotor. Advantageously, the speed of rotation of the principal shaft is 7-70 times greater than the speed of rotation of the drive shaft to which the second rotor and the wall scraper are attached. In an advantageous feature of the invention, the radial extent of the scraper increases toward the top of the container, thereby causing an increased flow of materials toward the central shaft in the vicinity of the top part of the container. BRIEF DESCRIPTION OF THE DRAWINGS Further advantages and features of the invention will be apparent from the description of an embodiment with reference to the drawing. The single FIGURE of the drawing is a side-elevational view of an apparatus for mixing materials according to the invention in partial vertical cross section. Reference numerals referring to parts identical with those of FIG. 1 in U.S. Pat. No. 4,107,792 are marked with primes. DESCRIPTION OF THE PREFERRED EMBODIMENT An apparatus for mixing materials according to the present invention is provided with a substantially cylindrical container 1' open at the top, into which a mixer 2' is inserted from above. The mixer 2' is provided with a shaft 4' on a suspension mount in a housing 3' indicated generally, the shaft being driveable at high speed by a drive motor 40. The lower, free end of the shaft 4' carries first rotor 17' consisting of a hub 18' coupled to the end of the shaft 4' and, extending therefrom, substantially radial, propeller-like rotor arms 21' the ends of which carry an annular disc 23'. Mounted vertically on the disc 23' are teeth 24' in the form of pins disposed parallel to one another at regular intervals around the periphery of the disc 23'. An annular disc 11' which is part of a second rotor unit 8' is disposed in the plane defined by the upper ends of the teeth 24' and also carries a row of equally spaced teeth 12' in the form of pins. The pins 12' extend downwardly from the annular disc 11' to the immediate vicinity of the surface of the annular disc 23'. The annular disc 11' of the second rotor 8' is held in its position by arms 41 disposed substantially parallel to the principal rotor shaft 4' and attached at their other end to a hollow shaft 42 which is concentric with and surrounds the shaft 4' of the first rotor 17'. The sense of rotation of the hollow shaft 42 is the same, as indicated by the arrow 43, as the sense of rotation of the shaft 4' of the first rotor 17' as indicated by the arrow 20'. Further attached to the hollow shaft 42 is a radially extending carrier arm 44 whose radially remote, free end carries a downwardly extending scraper 45 having a radially remote scraping edge 46 which may be in contact with the interior cylindrical wall 47 of the container 1' or at least lies in the immediate vicinity of that surface. The scraping attachment 45 may be rotated about an internal axis 48, thereby adjusting its angular position with respect to the carrier arm 44 as well as with respect to the prevailing tangent to the interior wall 47 of the container 1'. The hollow shaft 42 carrying the scraper 45 and the second rotor 8' is also rotated by the drive motor 40 at a constant speed which, depending on the dimensions of the apparatus may lie between 10 and 25 rpm. The rotational speed of the central shaft 4' which carries the first rotor 17' is substantially higher. The higher speed of rotation of the shaft 4' is obtained by the interposition of a steplessly controllable transmission (not shown) located within the housing 3'. In very large installations, the speed range which may be selected is between 150 and 500 rpm, whereas it may be for example between 500 and 1500 rpm in relatively small installations. The preferred rotational speed of the shaft 4' and its first rotor 17' is thus seen to be from 7-70 times greater than the speed of rotation of the hollow shaft 42 carrying the second rotor 8' and the scraper 45. The relative disposition of the stator teeth 12' and the rotor teeth 24' is as described in U.S. Pat. No. 4,107,792. As stated therein, the teeth 24 are in the form of pins having the same diameter and the same length as the teeth 12, also made in the form of pins. The two sets of teeth overlap in their lengthwise directions, as seen in FIG. 1 so that, when one tooth 24' on the rotor 17' passes the tooth 12' on the second rotor 8', a shearing slot is formed whose width can be several millimeters. The teeth 12', 24', are positioned axially parallel to the axis of rotation 28' of the shaft 4'. Similarly, the effects due to this disposition of the teeth and due to the relatively rapid rotation of the rotor teeth 24' which radially surround the rotor teeth 12', are virtually the same as obtained in the apparatus described in the aforementioned patent. Due to the high circumferential speed of the first rotor 17', which may be as high as 50 m/sec, the materials in the container 1' acquire a very high tangential acceleration which tends to generate a well-defined circular flow which is illustrated in the figure by flow lines 29' and 30'. It will be appreciated that, while the figure shows only those components of motion of the flow which occur in a vertical section, the motion would actually have rotational components which cannot be shown. In practice, the flow pattern is invariably three-dimensional. The existence of these flow patterns is further enhanced by the presence of the scraper 45 due to the fact that the scraper 45 increases the return flow of particles from the radially outward region of the container 1' toward the central shaft 4'. This return flow leads to an increased circulation of the individual particles so that they tend to pass the shearing slots formed between the teeth 12' and 24' still more often than would otherwise be the case. Furthermore, the presence of the scraper 45 prevents the deposition of any material on the wall 47, which materials might otherwise be lost to the forced circulation. The increased return flow due to the scraper is the result of an increase in the radial extent of the scraper toward the top of the container. In the simplest embodiment, the scraper 45 has a lower region 45a and an upper region 45b of greater radial extent than the lower region. Accordingly, the scraper exerts increased return flow forces on the fluid toward the central axis 28' in a region where the flow would tend to be the least agitated. The fact that both shafts rotate in the same sense brings the advantage that the scraper does not have to operate in opposition to the established rotational flows described above but moves in the same direction as these flows, thereby substantially reducing the energy requirements for driving the hollow shaft 42 carrying the scraper 45 and the second rotor 8'. The housing 3' which houses the drive motor 40, the shaft 4' and the hollow shaft 42 may be mounted in known manner on a pedestal 49 whose height may be adjustable, permitting the housing 3' to be moved upwardly as far as necessary to remove the mixing system 2' completely from the container 1'. The open top of the container 1' may be closed by a cover 51 mounted on a non-rotatable guide tube 50 concentrically surrounding the hollow shaft 42. The cover 51 may also be moved axially by means of a hydraulic drive mechanism 52. The cover 51 may be vacuum-sealed with respect to the container 1' in known manner. The cover 51 is provided with a vacuum sealable filler opening 53 and an evacuation valve 54. The lower part of the container 1' has an outlet valve 55. Due to the construction of the mixing apparatus of the present invention, which includes a slowly rotating scraper 45, it is no longer necessary, as was heretofore required, to cause the mixer 2' to execute an axial oscillatory (up and down) motion within the container 1'. This oscillatory motion required a substantial expenditure and introduced substantial sealing problems during vacuum operation because of the requirement of having to seal the cover 51 with respect to the shaft 4' in both rotary and axial motion. Accordingly, the construction of the present invention is particularly advantageous when the mixing apparatus is used in vacuum operation. It is to be understood that the foregoing description as well as the accompanying drawing relate to an illustrative embodiment of an apparatus set out by way of example and not by way of limitation. Numerous other embodiments and variants are possible without departing from the spirit and scope of the invention.

An apparatus for discontinuous mixing of substances, one of which is a liquid and especially suitable for the mixing of thixotropic materials. The mixer has a high speed rotor which cooperates with a more slowly rotating stator. Both rotor and stator are provided with teeth disposed on mutually concentric circles. When the teeth move past one another, shearing slots are formed. The drive shaft carrying the stator also carries at least one radially extending arm on which is mounted a wall scraper whose angle of attack with respect to the wall may be changed by rotation about an internal axis.

PRIORITY [0001] This application claims the benefit under 35 U.S.C. §119(a) of a Korean patent application filed in the Korean Intellectual Property Office on Jul. 5, 2011 and assigned Serial No. 10-2011-0066623, the entire disclosure of which is hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The preset invention relates to a method and apparatus in which a device terminal accesses a coordinator terminal in a communication system. More particularly, the present invention relates to a system and method supporting efficient operations of a plurality of sensor devices that periodically transmit sensing information in a Body Area Network (BAN). [0004] 2. Description of the Related Art [0005] Wireless Body Area Network (WBAN), which is under standardization as an international standard called Institute of Electrical and Electronic Engineers (IEEE) 802.15.6 TG6 BAN, aims to provide medical services such as telemedicine services over a communication network formed around three meters or less from the body, and to provide entertainment services in which wearable equipment for wearable computing or motion sensors are used. In addition, WBAN is under similar standardization as an international standard called IEEE 802.15.4j Medical BAN (MBAN), and 802.15.4j is defined as an amendment standard for using the existing 802.15.4 in a Medical BAN Service (MBANS) band of 2.36˜2.4 GHz. [0006] WBAN generally includes a coordinator and a plurality of devices such as various types of sensors attachable to the body. [0007] The main application of WBAN is to collect biometric information from medical sensors and to send the collected biometric information to medical institutions. A coordinator, which has a wire or wireless communication line connected to a medical institution server, sends data received from devices or sensors connected by WBAN to the medical institution server. For example, the coordinator may send the data received from the devices or sensors in an unprocessed form or after analyzing such data. [0008] In the WBAN healthcare system, because small-sized devices equipped with a mobile power supply such as a battery are mainly handled, reducing (e.g., minimizing) the power consumption of the devices is an important system requirement. Generally, a low duty cycling technique may be applied, for low-power implementation. As an example, the small-sized devices may be sensors having poor power conditions. [0009] FIG. 1 shows a data transmission process when it is operated by low duty cycling and when a beacon is used in an IEEE 802.15.4 WBAN according to the related art. [0010] Referring to FIG. 1 , when the data transmission process is operated by low duty cycling, the lower the duty cycling, the greater the number of nodes that have data during an inactive period. At the starting point of the next active period, the system attempts to transmit all of the data. [0011] As described above, in the WBAN according to the related art, when data is transmitted by low duty cycling, many nodes may have data during an inactive period due to the low duty cycling. Consequently, transmission of all of this data is attempted in the next active period. [0012] In this case, the WBAN according to the related art may deal with contention with the fixed initial backoff settings, for packet transmission. However, when the concentration of traffic is severe, it is difficult to solve this problem with the initial backoff settings which were made without recognizing this problem. [0013] In addition, when a number of packet transmission attempts rapidly increases in the next active period, the packet transmission attempts are concentrated at the same time in a Contention Access Period (CAP). Accordingly, traffic may occur during the packet transmission. [0014] Therefore, a need exists for an apparatus and method for controlling resource access by devices such that in a WBAN in which periodic data transmission is made, a plurality of devices may be prevented from causing a reduction in performance such as delays due to their excessive collisions in a Contention Access Period CAP [0015] The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure. SUMMARY OF THE INVENTION [0016] Aspects of the present invention are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a system and method for controlling resource access by devices such that in a Wireless Body Area Network (WBAN) in which periodic data transmission is made, a plurality of devices may be prevented from causing a reduction in performance such as delays due to their excessive collisions in a Contention Access Period (CAP). [0017] In accordance with an aspect of the present invention, a coordinator in a Mutual Broadcast Period (MBP) and CAP operating system for load control is provided. The coordinator includes a Radio Frequency (RF) unit for broadcasting a beacon frame, and a controller for determining whether contention for data transmission in a CAP due to backlogged traffic increases, by recognizing the number of connected devices, for broadcasting a beacon frame including information about an MBP used for load control to each device through the RF unit before the CAP if the contention for data transmission increases, for determining whether a load control broadcast message for determining existence of data load is received in the MBP from the device without error, and for sending a response to the load control broadcast message to the device. [0018] In accordance with another aspect of the present invention, a device in a MBP and CAP operating system for load control is provided. The device includes a RF unit for receiving a beacon frame broadcasted from a coordinator, and a controller for sending a load control broadcast message for determining existence of data load to the coordinator in an MBP based on information about the MBP upon receiving a beacon frame including information about an MBP used for load control from the coordinator before a CAP, for determining a type of a CAP depending on whether sending of the load control broadcast message is successful and whether packet transmission by other devices is successful, and for performing data transmission using a CAP corresponding to the determined CAP type. [0019] In accordance with another aspect of the present invention, a method for operating a MBP and CAP for load control in a coordinator is provided. The method includes determining whether contention for data transmission in a CAP due to backlogged traffic increases, by recognizing the number of connected devices, broadcasting a beacon frame including information about an MBP used for load control to each device before the CAP, if the contention for data transmission increases, determining whether the load control broadcast message is received without error, and sending a response to the load control broadcast message to the device. [0020] In accordance with another aspect of the present invention, a method for operating a MBP and CAP for load control in a device is provided. The method includes receiving a beacon frame including information about an MBP used for load control from a coordinator before a CAP, sending a load control broadcast message for determining existence of data load to the coordinator in the MBP based on information about the MBP, determining a type of a CAP depending on whether sending of the load control broadcast message is successful and whether packet transmission by other devices is successful, and performing data transmission using a CAP corresponding to the determined CAP type. [0021] Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0022] The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: [0023] FIG. 1 shows a data transmission process when it is operated by low duty cycling and when a beacon is used in an IEEE 802.15.4 Wireless Body Area Network (WBAN) according to the related art; [0024] FIG. 2 shows a structure of a superframe including a Mutual Broadcast Period (MBP) according to an exemplary embodiment of the present invention; [0025] FIG. 3 shows a superframe configured by dividing an MBP into Mutual Broadcast Zones (MBZs) and a Contention Access Period (CAP) into Contention Access Zones (CAZs) according to an exemplary embodiment of the present invention; [0026] FIG. 4 shows a structure of one MBZ according to an exemplary embodiment of the present invention; [0027] FIG. 5 shows a structure of a coordinator and a device according to an exemplary embodiment of the present invention; [0028] FIG. 6 shows a structure of a beacon frame according to an exemplary embodiment of the present invention; [0029] FIG. 7 shows a structure of an MBP field according to a first exemplary embodiment of the present invention; [0030] FIG. 8 shows a structure of a superframe including the MBP field and having no GTS according to the first exemplary embodiment of the present invention; [0031] FIG. 9 shows a structure of a superframe including the MBP field and having a GTS according to the first exemplary embodiment of the present invention; [0032] FIG. 10 shows a structure of an MBP field according to a second exemplary embodiment of the present invention; [0033] FIG. 11 shows a structure of a superframe according to the second exemplary embodiment of the present invention; [0034] FIG. 12 shows a structure of an MBP field according to a third exemplary embodiment of the present invention; [0035] FIG. 13 shows a structure of an MBP field according to a fourth exemplary embodiment of the present invention; [0036] FIG. 14 shows a structure of a superframe according to the third exemplary embodiment of the present invention; [0037] FIG. 15 shows a structure of a superframe according to the fourth exemplary embodiment of the present invention; [0038] FIG. 16 shows a process of performing load control using an MBP according to an exemplary embodiment of the present invention; [0039] FIGS. 17A and 17B show a flow diagram of a Carrier Sense Multiple Access-Collision Avoidance (CSMA-CA) algorithm in an Exclusive CAP according to an exemplary embodiment of the present invention; [0040] FIGS. 18A and 18B show a flow diagram of a CSMA-CA algorithm in a Background CAP according to an exemplary embodiment of the present invention; [0041] FIG. 19 shows a process of performing load control using an MBP in a coordinator according to an exemplary embodiment of the present invention; and [0042] FIG. 20 shows a process of performing load control using an MBP in a device according to an exemplary embodiment of the present invention. [0043] Throughout the drawings, in should be noted that like reference numbers are used to depict the same or similar elements, features, and structures. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS [0044] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. [0045] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. [0046] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces. [0047] FIG. 2 shows a structure of a superframe including a Mutual Broadcast Period (MBP) according to an exemplary embodiment of the present invention. [0048] Referring to FIG. 2 , the superframe includes a beacon frame B, an MBP, a Contention Access Period (CAP), and a Contention Free Period (CFP). [0049] In an exemplary embodiment of the present invention, the MBP is established between the beacon frame B and the Contention Access Period (CAP) as shown in FIG. 2 . Thus, before entering the CAP, devices may exchange information with each other, thereby ensuring proper load control in the CAP. [0050] Queue information about the number of packets accumulated thus far is sent in the MBP, thereby preventing transmission attempts from being concentrated at the same time in the CAP. [0051] In the exemplary embodiment of the present invention, load control in the CAP is made naturally in a distributed manner depending on the information that the devices have exchanged in the MBP. [0052] According to exemplary embodiments of the present invention, the MBP is smaller than the CAP in time period. As example, with regard to a length of the MBP, the coordinator may inform the devices of the length of the MBP by adding a field indicating the length of the MBP in the beacon frame B and including information about the length of the MBP or information about a start point of the CAP in the added field. This MBP operates by Carrier Sense Multiple Access-Collision Avoidance (CSMA-CA) similarly to the CAP, but the MBP may be set so as to consider light contention situations such as making a length of a backoff slot short because the MBP does not require transmission of a lot of data. [0053] FIG. 3 shows a superframe configured by dividing an MBP into Mutual Broadcast Zones (MBZs) and a CAP into Contention Access Zones (CAZs) according to an exemplary embodiment of the present invention. [0054] Referring to FIG. 3 , the superframe includes a beacon frame B, an MBP, and a CAP. The MBP includes at least one MBZ and the CAP includes at least one CAZ. [0055] Exemplary embodiments of the present invention propose MBZs and CAZs, for balanced load control. An MBZ corresponds to each of N zones obtained by dividing an MBP. Similarly, a CAZ corresponds to each of N zones obtained by dividing a CAP. MBZs correspond to CAZs on a one-to-one basis. [0056] For example, assume that the coordinator sets 6 MBZs in an MBP and 6 CAZs in a CAP. [0057] These MBZs and CAZs are used as a tool for load balancing, through load control. As an example, MBZ # 1 corresponds to CAZ # 1 , MBZ # 2 corresponds to CAZ # 2 , and in this way, MBZ # 6 corresponds to CAZ # 6 . [0058] One MBZ will be described in detail with reference to FIG. 4 . [0059] FIG. 4 shows a structure of one MBZ according to an exemplary embodiment of the present invention. [0060] Referring to FIG. 4 , one MBZ includes a plurality of mini backoff slots. When attempting to transmit data in an MBZ, a device transmits data at the boundary of a mini backoff slot in accordance with a slotted CSMA-CA operation. [0061] According to exemplary embodiments of the present invention, the data that a plurality of devices attempt to send in one MBZ, includes queue information of each device, and a device detects transmission by other devices based on the slotted CSMA-CA operation, and transmits data by a backoff algorithm. However, when there are a large number of devices, the devices may not transmit data in an MBZ. [0062] FIG. 5 shows a structure of a coordinator and a device according to an exemplary embodiment of the present invention. [0063] Referring to FIG. 5 , a coordinator 100 includes a controller 101 , a Radio Frequency (RF) unit 102 , and a memory 103 , and a device 110 includes a controller 111 , an RF unit 112 , a sensing unit 113 , and a memory 114 . [0064] According to exemplary embodiments of the present invention, if the controller 101 in the coordinator 100 expects an increase in contention by data transmission in a CAP due to backlogged traffic by recognizing the number of connected devices, the controller 101 informs the devices of the expected increase in contention by including MBP information in a beacon frame B. For example, the MBP information includes a period length and the number of MBZs. [0065] Thereafter, upon receiving a queue information packet sent for load control from the device 110 without error, the controller 101 sends a response or an Acknowledgement (ACK) to the device 110 . If there is traffic that the coordinator 100 desires to send to the device 110 , the controller 101 sets a destination address as a broadcast address, sends a broadcast message to the broadcast address, and sends no ACK to the device 110 that has received the broadcast message. The queue information packet includes an indicator indicating a control packet sent in an MBP, and may further include a queue length associated with Quality of Service (QoS), a traffic type, a battery status, and the like. The queue information packet includes queue information in terms of other utilizations of an MBZ, and in fact, only for load control resource access, the queue information may be minimized or not. The queue information packet may be called a ‘load control broadcast message’. [0066] The RF unit 102 in the coordinator 100 broadcasts a beacon frame B, and sends an ACK to the device 110 upon receiving a queue information message from the device 110 . [0067] The memory 103 in the coordinator 100 stores information used for data transmission, and may store MBP information such as a period length and the number of MBZs. [0068] Next, the controller 111 in the device 110 obtains MBP information from the coordinator 100 , finds the required amount of resources needed for packet transmission, and then determines the number of CAZs based thereon. Thereafter, the controller 111 arbitrarily selects one or multiple MBZs, the number of which corresponds to the found number of CAZs, from among all MBZs. [0069] To transmit a packet in a CAP, the controller 111 first transmits a message packet including queue information to the coordinator 100 in a mini backoff slot at an MBZ point selected from a total of N MBZs in an MBP. [0070] Upon receiving an ACK from the coordinator 100 , the controller 111 determines whether to use a CAZ corresponding to the MBZ as an Exclusive CAP, and stores it in the memory 114 . Upon receiving no ACK from the coordinator 100 , the controller 111 retries the packet transmission, considering that a Negative Acknowledgement (NACK) is received. If the transmission in the selected MBZ is not successful, the controller 111 selects again one of the remaining unselected MBZs. The term ‘Exclusive CAP’ as used herein may refer to a period in which the device 110 may transmit more data than an amount of data, which is set by default. [0071] While not transmitting its queue information packet in the selected MBZ, the controller 111 receives queue information packets from other devices in a listening state, and upon receiving ACKs for the queue information packets from the coordinator 100 , the controller 111 stores the queue information packets in the memory 114 . This may be used when the controller 111 adjusts CSMA-CA variables in a CAP. [0072] The controller 111 performs listening only, in the unselected MBZs. If there is no queue information packet that the device 110 has transmitted in the MBZ and received an ACK therefor, the controller 111 determines to use a CAZ corresponding to the MBZ as a Normal CAP. The term “Normal CAP’ as used herein may refer to a period in which the device 110 may transmit data in the amount of data, which is set by default. [0073] If the device 110 fails to transmit the queue information packet in all MBZs, the controller 111 determines to use the full CAP as a Background CAP. The term ‘Background CAP’ as used herein may refer to a period in which the device 110 may transmit data in the remaining period among the entire data transmission period. [0074] The RF unit 112 in the device 110 is configured to transmit and receive information. For example, the RF unit 112 receives a beacon frame broadcasted from the coordinator 100 , transmits a queue information packet to the coordinator 100 in each MBZ corresponding to each CAZ, and receives an ACK from the coordinator 100 . [0075] The sensing unit 113 in the device 110 outputs sensed data to the controller 111 . [0076] The memory 114 in the device 110 stores information needed for data transmission, and may store the queue information packet received from the coordinator 100 . The memory 114 stores in advance CAP information corresponding to the transmission results of the queue information packet. For example, the CAP information includes an Exclusive CAP, a Normal CAP and a Background CAP. [0077] As a result, exemplary embodiments of the present invention may enable efficient resource access by performing load control in a distributed manner for data transmission/reception, contributing to a reduction in access delay and power consumption and enabling appropriate QoS control. [0078] A structure of the above-described beacon frame B will be described in detail below with reference to FIG. 6 . [0079] FIG. 6 shows a structure of a beacon frame according to an exemplary embodiment of the present invention. [0080] Referring to FIG. 6 , the beacon frame includes a field for Frame Control, a field for Sequence Number, an Addressing field, an Auxiliary Security Header, a field for Superframe Specification, a Pending address field, a Beacon Payload, an MBP field, a Frame Check Sequence (FCS). The beacon frame may also include a GTS field. [0081] According to exemplary embodiments of the present invention, it is appropriate for the MBP field to include variable fields, similarly to GTS fields, rather than the Superframe Specification field giving information, because the MBP field is a field newly added to the existing specification. Details and structure of the MBP field will be described in detail below with reference to FIGS. 7 to 15 . [0082] FIG. 7 shows a structure of an MBP field according to a first exemplary embodiment of the present invention. [0083] A MBZ/CAZ Count field (with 4 bits, having a value of 0 to 15) indicates the number of MBZs/CAZs. [0084] A MBZ Length field indicates a length of one MBZ on a slot basis. [0085] A CAZ Length field indicates a length of one CAZ on a slot basis. [0086] Referring to FIG. 7 , if MBZ/CAZ Count is 3, MBZ length is 1, and CAZ length is 4, then slots # 0 to # 2 operate as an MBP, slots # 3 to # 14 operate as CAZs corresponding to MBZs, and the remaining slot # 15 may operate as a Normal CAP. [0087] Two different types of superframes including the MBP field according to a first exemplary embodiment of the present invention may be represented as shown in FIGS. 8 and 9 . FIG. 8 shows a type of a superframe without GTS, and FIG. 9 shows a type of a superframe to which GTS is applied. [0088] FIG. 8 shows a structure of a superframe including the MBP field and having no GTS according to the first exemplary embodiment of the present invention. FIG. 9 shows a structure of a superframe including the MBP field and having a GTS according to the first exemplary embodiment of the present invention. [0089] Referring to FIG. 8 , the superframe includes a beacon frame, an MBP, and a CAP. The MBP includes at least one MBZ and the CAP includes at least one CAZ. [0090] Referring to FIG. 9 , the superframe includes a beacon frame, an MBP, and a CAP, and a GTS. For example, the GTS may be included in a Circuit Emulation over Packet (CEP). The CEP may include a plurality of GTSs. [0091] FIG. 10 shows a structure of an MBP field according to a second exemplary embodiment of the present invention. [0092] Referring to FIG. 10 , the MBP field includes an MBZ/CAZ Count, an MBZ Ending Slot, and a CAZ Ending Slot. [0093] MBZ Ending Slot indicates the last slot among the existing 16 available slots, which is to be used for an MBP. [0094] CAZ Ending Slot indicates a slot of the last CAZ in a CAP. [0095] Although a first exemplary embodiment of the present invention is similar to a second exemplary embodiment of the present invention, when the CAZ Ending Slot is not defined, a CAP from the next slot of MBZ Ending Slot to the final CAP slot of the Superframe Specification field will be divided by a number in the MBZ/CAZ Count field in the same length. [0096] When the CAZ Ending Slot is defined, if the CAZ Ending Slot is greater than the final CAP slot, it is regarded as the same value as that of the final CAP slot, and a CAP from the next slot of MBZ Ending Slot to CAZ Ending Slot will be divided by a number in the MBZ/CAZ Count field in the same length. In this case, a CAZ length will not be a multiple of a superframe slot. An MBP from 0 to MBZ Ending Slot is also divided by a number in the MBZ/CAZ Count field in the same length and used as MBZ field. [0097] When the MBP field according to a second exemplary embodiment of the present invention is used, for each MBZ/CAZ, a CAP from the next slot of MBZ Ending Slot to a superframe slot designated by CAZ Ending Slot will be divided by a number in the MBZ/CAZ Count field in the same length. [0098] A superframe including the MBP field according to the second exemplary embodiment of the present invention may be represented as shown in FIG. 11 . [0099] FIG. 11 shows a structure of a superframe according to the second exemplary embodiment of the present invention. [0100] Referring to FIG. 11 , the superframe includes a beacon field, an MBP, a CAP, and a GTS. The MBP field includes at least one MBZ, and the CAP includes at least one CAZ. As an example, the GTS may be included in a CFP. [0101] In addition, MBP Duration (MD) determined by an MBP Order value rather than based on the superframe slot as in the above-described first and second exemplary embodiments of the present invention may be configured with an MBP. An MBP Order field is a field used to adjust a size of the superframe, and an MBP Order value may be determined by the user or the coordinator's algorithm, like the superframe order or beacon order, and may have 2 bits in an exemplary embodiment of the present invention. [0102] The configured MBP fields may be represented as shown in FIGS. 12 and 13 . [0103] FIG. 12 shows a structure of an MBP field according to a third exemplary embodiment of the present invention, and FIG. 13 shows a structure of an MBP field according to a fourth exemplary embodiment of the present invention. [0104] Referring to FIG. 12 , the MBP field includes an MBP Order, an MBZ/CAZ Count, and a CAZ Length. [0105] Referring to FIG. 13 , the MBP field includes an MBP Order, an MBZ/CAZ Count, and a CAZ Ending Slot. [0106] Similarly to Superframe Duration (SD) and Beacon Interval (BI), MD may be calculated by Equation (1) below. [0000] MD =aBaseSuperframeDuration*2 MO symbols   (1) [0107] An MBP is inserted as a new period ahead of a CAP before a start of a superframe slot # 0 depending on the calculated MD, and other fields in the MBP field according to the third and fourth exemplary embodiments of the present invention are the same as those in the MBP field according to the first and second exemplary embodiments of the present invention. [0108] Superframes including the MBP fields according to the third and fourth exemplary embodiments of the present invention may be represented as shown in FIGS. 14 and 15 . [0109] FIG. 14 shows a structure of a superframe according to the third exemplary embodiment of the present invention, and FIG. 15 shows a structure of a superframe according to the fourth exemplary embodiment of the present invention. [0110] Referring to FIG. 14 , the superframe includes a beacon field, an MBP, a CAP, and a GTS. The MBP may include at least one MBZ, and the CAP may include at least one CAZ. As an example, the GTS may be included in a CFP. [0111] Referring to FIG. 15 , the superframe includes a beacon field, an MBP, a CAP, and a GTS. The MBP may include at least one MBZ, and the CAP may include at least one CAZ. As an example, the GTS may be included in a CFP. [0112] An operation of the device will be described in detail below with reference to FIG. 16 . [0113] FIG. 16 shows a process of performing load control using an MBP according to an exemplary embodiment of the present invention. [0114] According to exemplary embodiments of the present invention, if a plurality of devices attempt transmission of a queue information packet in one MBZ, all or some of the attempting devices may succeed in the attempts, or all of the attempting devices may fail in the attempts. [0115] When all of the attempting devices succeed in the attempts, all of the devices operate in a CAP corresponding to an Exclusive CAP (E-CAP). However, when there are a large number of devices, only some of the devices may succeed in the attempts generally, because it will be unlikely that all of the devices may succeed in the attempts. Some devices having succeeded in the attempts may operate in a CAP corresponding to an Exclusive CAP, but the remaining devices having failed in the attempts may not use the associated CAZs. If all of the devices have failed in their respective attempts, the devices having made the attempts may not use the associated CAZs. However, the devices, which have been performing listening instead without making the attempts, may use the associated CAZs as a Normal CAP. The devices, which have finally failed in transmission in an MBP because they have failed in transmission in all MBZs where they attempted the transmission, may use the entire CAP as a Background CAP. [0116] Referring to FIG. 16 , it is assumed that a superframe is divided into 6 CAZs in a CAP and 6 MBZs in an MBP, and as the coordinator broadcasts this information to devices, the devices recognize the information in advance. [0117] For example, in a case in which first and fourth devices delivered a Queue (Q) information packet to the coordinator in MBZ # 1 among 6 MBZs in an MBP, second, third and fifth devices determine to transmit data using a Normal CAP N-CAP at CAZ # 1 in a CAP, when no ACK is received from the coordinator. [0118] In a case in which second and fifth devices delivered a Q information packet to the coordinator in MBZ # 2 among 6 MBZs in an MBP, the second and fifth devices determine to transmit data using an Exclusive CAP E-CAP at CAZ # 2 in a CAP upon receiving an ACK from the coordinator. [0119] In a case in which first and fifth devices delivered a Q information packet to the coordinator in MBZ # 3 among 6 MBZs in an MBP, only the fifth device determines to transmit data using an Exclusive CAP E-CAP at CAZ # 3 in a CAP, if no ACK is received at the first device from the coordinator and an ACK is received at the fifth device from the coordinator. [0120] In a case in which a first device delivered a Q information packet to the coordinator in MBZ # 4 among 6 MBZs in an MBP, only the first device determines to transmit data using an Exclusive CAP E-CAP at CAZ # 4 in a CAP if an ACK is received at the first device from the coordinator. [0121] In a case in which third and fourth devices delivered a Q information packet to the coordinator in MBZ # 5 among 6 MBZs in an MBP, first, second and fifth devices determine to transmit data using a Normal CAP N-CAP at CAZ # 5 in a CAP if no ACK is received from the coordinator. [0122] In a case in which third and fourth devices delivered a Q information packet to the coordinator in MBZ # 6 among 6 MBZs in an MBP, only the third device determines to transmit data using an Exclusive CAP E-CAP at CAZ # 6 in a CAP, if an ACK is received at the third device from the coordinator and no ACK is received at the fourth device from the coordinator. [0123] The fourth device, which has failed in transmission of a Q information packet at all of 6 MBZs in an MBP, determines to transmit data using a Background CAP (B-CAP) in a CAP. [0124] As described above, an operation in a CAP is based on the CSMA-CA resource access scheme which is defined according to each of the Exclusive CAP, Normal CAP and Background CAP determined in an MBP in advance. Although the detailed operation in each period will not be described herein, it is general that an Exclusive CAP may be set for a device to attempt resource access more strongly than usual, and a Background CAP may be set for a device to attempt resource access more weakly than usual. In this regard, the Exclusive CAP, Normal CAP and Background CAP may have, for example, the following variables and algorithms. Specifically, CSMA-CA algorithms, in which the foregoing is reflected, will be described with reference to FIGS. 17A , 17 B, 18 A and 18 B. Operations on the CSMA-CA algorithms in FIGS. 17A , 17 B, 18 A and 18 B are the same as an operation of the general CSMA-CA algorithm, and variables and algorithm setting values by the Exclusive CAP and Background CAP will be applied as described below. [0125] FIGS. 17A and 17B show a flow diagram of a CSMA-CA algorithm in an Exclusive CAP according to an exemplary embodiment of the present invention. [0126] Referring to FIG. 17A , at step 1701 it is determined whether a CSMA-CA operation is a slotted CSMA-CA operation. If it is a slotted CSMA-CA operation, then the process proceeds to step 1708 . At step 1708 , the NB may be set such that NB=0, and CW may be set such that CW=2. Upon setting NB and CW, the process proceeds to step 1709 . At step 1709 , it is determine whether battery life extension is required. If battery life extension is not required, then the process proceeds to step 1710 at which BE may be set such that BE=less of (2, macMinBE) and thereafter the process proceeds to step 1712 . If at step 1709 , it is determined that battery life extension is required, then BE may be set such that BE=macMinBE at step 1711 . Thereafter, the process proceeds to step 1712 . At step 1712 , the back off period boundary is located and the process proceeds to step 1713 . At step 1713 , a delay for a random number of backoff periods is performed. For example, the delays may be such that a delay of random(2 BE -1) unit backoff periods is performed. After the delay, the process proceeds to step 1714 at which a CCA on backoff period boundary is performed and the process proceeds to step 1715 . At step 1715 , it is determined whether a channel is idle. [0127] Referring to FIG. 17A , if the channel is determined to be idle at step 1715 , the process proceeds to step 1716 at which an Exclusive CAP is set less than a Normal CAP in terms of setting values: macMinBE and macMaxBE, and in a BE incremental equation in step 1716 , BE may be set such that BE=min(BE+0.5, macMaxBE), and maxCSMAbackoffs is set large. In an NE incremental equation in step 1716 , NB may be set such that NB=NB+0.5. When NB or BE is used, their integers may be taken and used. After step 1716 , the process proceeds to step 1717 at which it is determined whether NB is greater than macMaxCSMABackoffs. If NB is not greater than macMaxCSMABackoffs, then the process returns to step 1713 . If NB is greater than macMaxCSMABackoffs, then the process ends in failure. [0128] If the channel is determined to not be idle at step 1715 , then the process proceeds to step 1718 at which CW may be set such that CW=CW-1. After the CW is set, the process proceeds to step 1719 at which it is determined whether CW=0. If CW is determined to not equal 0, then the process returns to step 1714 . However, if CW is determined to equal 0, then the process ends in success. [0129] Referring to FIGS. 17A and 17B , if at step 1701 it is determined that the CSMA-CA operation is not slotted, then the process proceeds to step 1702 . At step 1702 , the NB may be set such that NB=0 and ME may be set such that BE=macMinBe. Thereafter, the process proceeds to step 1703 at which a delay is performed. As an example, the delay may be for a number of unit backoff periods corresponding to random(2 BE -1). Thereafter, the process proceeds to step 1704 at which a CCA is performed. After performing the CCA, the process proceeds to step 1705 at which it is determined whether the channel is idle. If the channel is determined to be idle at step 1705 , then the process proceeds to step 1706 at which NB may be set such that NB=NB+0.5 and BE may be set such that BE=min(BE+0.5, macMaxBE). Thereafter, the process proceeds to step 1707 at which it is determined whether NB is greater than macMaxCSMABackoffs. If it is determined that NB is not greater than macMaxCSMABackoffs, then the process returns to step 1703 . If NB is determined to be greater than macMaxCSMABackoffs, then the process ends in failure. [0130] Conversely, if at step 1705 it is determined that the channel is idle, then the process ends in success. [0131] According to exemplary embodiments of the present invention, a Normal CAP is the same as macMinBE, macMaxBE, and maxCSMAbackoffs values used by the existing CSMA-CA algorithm in a CAP. BE has min([BE+1], macMaxBE) and NB has NB+1. [0132] FIGS. 18A and 18B show a flow diagram of a CSMA-CA algorithm in a Background CAP according to an exemplary embodiment of the present invention. [0133] Referring to FIG. 18A , at step 1801 it is determined whether a CSMA-CA operation is a slotted CSMA-CA operation. If it is a slotted CSMA-CA operation, then the process proceeds to step 1808 . At step 1808 , the NB may be set such that NB=0, and CW may be set such that CW=2. Upon setting NB and CW, the process proceeds to step 1809 . At step 1809 , it is determine whether battery life extension is required. If battery life extension is not required, then the process proceeds to step 1810 at which BE may be set such that BE=less of (2, macMinBE) and thereafter the process proceeds to step 1812 . If at step 1809 , it is determined that battery life extension is required, then BE may be set such that BE=macMinBE at step 1811 . Thereafter, the process proceeds to step 1812 . At step 1812 , the back off period boundary is located and the process proceeds to step 1813 . At step 1813 , a delay for a random number of backoff periods is performed. For example, the delays may be such that a delay of random(2 BE -1) unit backoff periods is performed. After the delay, the process proceeds to step 1814 at which a CCA on backoff period boundary is performed and the process proceeds to step 1815 . At step 1815 , it is determined whether a channel is idle. [0134] Referring to FIG. 18A , if the channel is determined to be idle at step 1815 , the process proceeds to step 1816 at which a Background CAP is set greater than a Normal CAP in terms of setting values: macMinBE and macMaxBE. In a BE incremental equation in step 1816 , BE may be set such that BE=min(BE+2, macMaxBE), and maxCSMAbackoffs may be set small. In an NB incremental equation in step 1816 , NB may be set such that NB=NB+2. [0135] NB corresponds to the number of retries due to a backoff made at one access attempt. CW is the number of backoff periods needed to check whether the channel is in an idle state. BE is related to the number of backoff intervals for which a device should wait before performing channel sensing, and the device may select any number from among numbers of 0 to 2BE-1 before its operation. [0136] After step 1816 , the process proceeds to step 1817 at which it is determined whether NB is greater than macMaxCSMABackoffs. If NB is not greater than macMaxCSMABackoffs, then the process returns to step 1813 . If NB is greater than macMaxCSMABackoffs, then the process ends in failure. [0137] If the channel is determined to not be idle at step 1815 , then the process proceeds to step 1818 at which CW may be set such that CW=CW-1. After the CW is set, the process proceeds to step 1819 at which it is determined whether CW=0. If CW is determined to not equal 0, then the process returns to step 1814 . However, if CW is determined to equal 0, then the process ends in success. [0138] Referring to FIGS. 18A and 18B , if at step 1801 it is determined that the CSMA-CA operation is not slotted, then the process proceeds to step 1802 . At step 1802 , the NB may be set such that NB=0 and ME may be set such that BE=macMinBe. Thereafter, the process proceeds to step 1803 at which a delay is performed. As an example, the delay may be for a number of unit backoff periods corresponding to random(2 BE -1). Thereafter, the process proceeds to step 1804 at which a CCA is performed. After performing the CCA, the process proceeds to step 1805 at which it is determined whether the channel is idle. If the channel is determined to be idle at step 1805 , then the process proceeds to step 1806 at which NB may be set such that NB=NB+2 and BE may be set such that BE=min(BE+2, macMaxBE). Thereafter, the process proceeds to step 1807 at which it is determined whether NB is greater than macMaxCSMABackoffs. If it is determined that NB is not greater than macMaxCSMABackoffs, then the process returns to step 1803 . If NB is determined to be greater than macMaxCSMABackoffs, then the process ends in failure. [0139] Conversely, if at step 1805 it is determined that the channel is idle, then the process ends in success. [0140] According to exemplary embodiments of the present invention, even in the same CAZ, differentiated access may be performed based on the queue information exchanged in an MBP in advance, taking into account inter-device QoS. [0141] FIG. 19 shows a process of performing load control using an MBP in a coordinator according to an exemplary embodiment of the present invention. [0142] In step 1900 , the coordinator 100 determines whether contention for data transmission in a CAP due to backlogged traffic has increased. If the contention has increased, the coordinator 100 proceeds to step 1902 . Otherwise, the controller 100 performs common data transmission in step 1901 . [0143] In step 1902 , the controller 100 generates a beacon frame including MBP information and broadcasts it to devices. [0144] The coordinator 100 determines in step 1903 whether a queue information packet for load control is received from each device without error in an MBP. If the queue information packet is received without error, the coordinator 100 proceeds to step 1905 . Otherwise, the coordinator 100 sends no response (or ACK) to each device in step 1904 . [0145] In step 1905 , the coordinator 100 sends a response to the queue information packet received without error, to each device. [0146] FIG. 20 shows a process of performing load control using an MBP in a device according to an exemplary embodiment of the present invention. [0147] In step 2000 , the device 110 receives a beacon frame including MBP information from the coordinator 100 . [0148] In step 2001 , the device 110 finds the required amount of resources needed for packet transmission based on the received MBP information, and then determines the number of CAZs depending on the found required amount of resources. [0149] In step 2002 , the device 110 determines the number of MBZs, which corresponds to the determined number of CAZs. The number of MBZs is equal to the number of CAZs. [0150] In step 2003 , the device 110 transmits a queue information packet for load control to the coordinator 100 in an MBZ corresponding to the time point selected from among the determined number of MBZs. [0151] In step 2004 , the device 110 determines a CAP type depending on whether its transmission of a queue information packet is successful and whether packet transmissions by other devices are successful. For example, the device 110 may determine any one of an Exclusive CAP, a Normal CAP, and a Background CAP depending on whether its transmission of a queue information packet is successful. [0152] In step 2005 , the device 110 performs a data transmission/reception operation using the determined CAP. [0153] For example, upon receiving a response message to the queue information packet from the coordinator 100 , the device 110 determines a type of CAP as an Exclusive CAP, determining that its transmission of a queue information packet is successful, and performs data transmission using the determined Exclusive CAP. [0154] If transmissions of a queue information packet by other devices are failed, the device 110 determines a type of CAP as a Normal CAP, and performs data transmission using the determined Normal CAP. [0155] If transmissions of a queue information packet in an MBP are all failed, the device 110 determines a type of CAP as a Background CAP, and performs data transmission using the determined Background CAP. [0156] As is apparent from the foregoing description, in operations of a coordinator and a device, devices participating in packet transmission/reception may receive the packets which are transmitted and received in an MBZ. For example, if another device receives the packet whose address is designated as an address of a specific device, such as unicast, in an MBZ, then the device may demodulate the packet regardless of its original destination so that the packet transmitted/received between the coordinator and the specific device may be delivered to other devices, making it possible to determine whether the packet transmission is successful. In addition, as a destination address of a queue information packet or a response packet is set as a broadcast address, the packet may be delivered not only to the device but also to the coordinator, making it possible to determine whether the packet transmission is successful. In this case, the coordinator broadcasts a response to the received packet. [0157] In this manner, exemplary embodiments of the present invention may enable efficient resource access by performing load control in a distributed manner, for data transmission/reception, thus contributing to a reduction in access delay and power consumption and enabling appropriate QoS control. [0158] While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.

A method and a system for operating a Mutual Broadcast Period (MBP) and Contention Access Period (CAP) for load control are provided. The proposed system and method is suitable for a short-range communication environment such as communication environment in or around the human body, and is for a mesh network communication environment in which one piconet is formed around the human body or a plurality of devices are connected. When signals carrying biometric information are periodically received from a plurality of sensor devices for medical purposes, the system and method may achieve efficient resource access by performing load control in a distributed manner, contributing to a reduction in access delay and power consumption and enabling appropriate QoS control.

RELATED APPLICATIONS [0001] This is a continuation-in-part of copending and commonly owned U.S. Ser. No. 08/534,126 filed Sep. 26, 1995, entitled “PREFORM AND CONTAINER WITH CRYSTALLIZED NECK FINISH AND METHOD OF MAKING THE SAME,” by Wayne N. Collette and Suppayan M. Krishnakumar, which in turn is a continuation-in-part of copending and commonly owned U.S. Ser. No. 08/499,570 filed Jul. 7, 1995, entitled “APPARATUS AND METHOD FOR MAKING MULTILAYER PREFORMS,” by Suppayan M. Krishnakumar and Wayne N. Collette, both of which are hereby incorporated by reference in their entirety. FIELD OF THE INVENTION [0002] The present invention relates to a method and apparatus for making multilayer injection-molded plastic articles such as preforms, wherein the successive molding of an inner sleeve and outer layer enables cost-effective production of multilayer preforms for pasteurizable, hot-fillable, and returnable and refillable beverage containers. BACKGROUND OF THE INVENTION [0003] There is described in U.S. Pat. No. 4,609,516 to Krishnakumar et al. a method for forming multilayer preforms in a single injection mold cavity. In that method, successive injections of different thermoplastic materials are made into the bottom of the mold cavity. The materials flow upwardly to fill the cavity and form for example a five-layer structure across the sidewall. This five-layer structure can be made with either two materials (i.e., the first and third injected materials are the same) or three materials (i.e., the first and third injected materials are different). Both structures are in widespread commercial use for beverage and other food containers. [0004] An example of a two-material, five-layer (2M, 5L) structure has inner, outer and core layers of virgin polyethylene terephthalate (PET), and intermediate barrier layers of ethylene vinyl alcohol (EVOH). An example of a three-material, five-layer (3M, 5L) structure has inner and outer layers of virgin PET, intermediate barrier layers of EVOH, and a core layer of recycled or post-consumer polyethylene terephthalate (PC-PET). Two reasons for the commercial success of these containers are that: (1) the amount of relatively expensive barrier material (e.g., EVOH) can be minimized by providing very thin intermediate layers; and (2) the container resists delamination of the layers without the use of adhesives to bond the dissimilar materials. Also, by utilizing PC-PET in the core layer, the cost of each container can be reduced without a significant change in performance. [0005] Although the above five-layer, and other three-layer (see for example U.S. Pat. No. 4,923,723) structures work well for a variety of containers, as additional high-performance and expensive materials become available there is an on-going need for processes which enable close control over the amount of materials used in a given container structure. For example, polyethylene naphthalate (PEN) is a desirable polyester for use in blow-molded containers. PEN has an oxygen barrier capability about five times that of PET, and a higher heat stability temperature—about 250° F. (120° C.) for PEN, compared to about 175° F. (80° C.) for PET. These properties make PEN useful for the storage of oxygen-sensitive products (e.g., food, cosmetics, and pharmaceuticals), and/or for use in containers subject to high temperatures (e.g., refill or hot-fill containers). However, PEN is substantially more expensive than PET and has different processing requirements: Thus, at present the commercial use of PEN is limited. [0006] Another high-temperature application is pasteurization—a pasteurizable container is filled and sealed at room temperature, and then exposed to an elevated temperature bath for about ten minutes or longer. The pasteurization process initially imposes high temperatures and positive internal pressures, followed by a cooling process which creates a vacuum in the container. Throughout these procedures, the sealed container must resist deformation so as to remain acceptable in appearance, within a designated volume tolerance, and without leakage. In particular, the threaded neck finish must resist deformation which would prevent a complete seal. [0007] A number of methods have been proposed for strengthening the neck finish. One approach is to add an additional manufacturing step whereby the neck finish, of the preform or container, is exposed to a heating element and thermally crystallized. However, this creates several problems. During crystallization, the polymer density increases, which produces a volume decrease; therefore, in order to obtain a desired neck finish dimension, the as-molded dimension must be larger than the final (crystallized) dimension. It is thus difficult to achieve close dimensional tolerances and, in general, the variability of the critical neck finish dimensions after crystallization are approximately twice that prior to crystallization. Another detriment is the increased cost of the additional processing step, as it requires both time and the application of energy (heat). The cost of producing a container is very important because of competitive pressures and is tightly controlled. [0008] An alternative method of strengthening the neck finish is to crystallize select portions thereof, such as the top sealing surface and flange. Again, this requires an additional heating step. Another alternative is to use a high T g material in one or more layers of the neck finish. This also involves more complex injection molding procedures and apparatus. [0009] Thus, it would be desirable to provide an injection-molded article such as a preform which incorporates certain high-performance materials, and a commercially acceptable method of manufacturing the same. SUMMARY OF THE INVENTION [0010] The present invention is directed to a method and apparatus for making a multilayer injection-molded plastic article, such as a preform, which is both cost-effective and enables control over the amounts of materials used in the various layers and/or portions of the article. [0011] According to a method/embodiment of the invention, an inner sleeve is molded on a first core positioned in a first mold cavity. The inner sleeve is only partially cooled before being transferred while still at an elevated temperature to a second mold cavity where an outer layer is molded over the inner sleeve. By providing the inner sleeve in the second mold cavity at the elevated temperature, bonding between the inner sleeve and outer layer is enabled during the second molding step, such that layer separation is avoided in the final molded article. The inner sleeve may comprise a full-length inner sleeve, extending substantially the full length of the article, or alternatively may comprise only an upper portion of the article, in which case the outer layer comprises a lower portion of the article and there is some intermediate portion in which the outer layer is bonded to the inner sleeve. [0012] In one embodiment, a first thermoplastic material is used to make an inner sleeve which comprises a neck finish portion of the preform. The first thermoplastic material is preferably a thermal resistant material having a relatively high T g , and/or forms a crystallized neck finish during the first molding step. In contrast, a lower body portion of the preform is made of a second thermoplastic material having a relatively lower thermal resistance and/or lower crystallization rate compared to the first material, and forms a substantially amorphous body-forming portion of the preform. In one example, by achieving crystallization in the neck finish during the first molding step, the initial and finish dimensions are the same so that the dimensional variations caused by the prior art post-molding crystallization step (and the expense thereof) are eliminated. Also, a higher average level of crystallization can be achieved in the finish, by utilizing the higher melt temperatures and/or elevated pressures of the molding process. [0013] In another embodiment, a full-length body sleeve is provided made of a high-performance thermoplastic resin, such as PEN homopolymer, copolymer or blend. The PEN inner sleeve provides enhanced thermal stability and reduced flavor absorption, both of which are useful in refill applications. The amount of PEN used is minimized by this process which enables production of a very thin inner sleeve layer, compared to a relatively thick outer layer (made of one or more lower-performance resins). [0014] Another aspect of the invention is an apparatus for the cost-effective manufacture of such preforms. The apparatus includes at least one set of first and second molding cavities, the first mold cavity being adapted to form the inner sleeve and the second mold cavity adapted to form the outer layer. A transfer mechanism includes at least one set of first and second cores, wherein the cores are successively positionable in the first and second molding cavities. In one cycle, a first core is positioned in a first mold cavity while a first inner sleeve is molded on the first core, while a second core, carrying a previously-molded second inner sleeve, is positioned in a second mold cavity, for molding a second outer layer over the second inner sleeve. By simultaneously molding in two sets of cavities, an efficient process is provided. By molding different portions/layers of the articles separately in different cavities, different temperatures and/or pressures may be used to obtain different molding conditions and thus different properties in the different portions/layers. For example, it is possible to mold the crystallized neck finish portion in a first cavity, while molding a substantially amorphous outer layer in the second cavity. [0015] The resulting injection-molded articles, and/or expanded injection-molded articles, may thus have a layer structure which is not obtainable with prior processes. [0016] The following chart provides temperature/time/pressure ranges for certain preferred embodiments, which are described in greater detail in the following sections: [0017] a) for an inner sleeve of PEN polymer material and an outer layer of PET polymer material range (on the order of) first molding step: core temperature  5-80° C. mold cavity temperature 40-120° C. melt temperature 275-310° C.  cycle time 4-8 seconds outer surface temperature of sleeve 60-120° C. second molding step: core temperature  5-80° C. mold cavity temperature  5-60° C. cycle time 20-50 seconds pressure 8000-15,000 psi [0018] b) for an inner sleeve of crystallized polyester material and an outer layer of PET polymer material range (on the order of) first molding step: core temperature  5-60° C. mold cavity temperature 80-150° C. melt temperature 270-310° C.  cycle time 5-8 seconds outer surface temperature of sleeve 80-140° C. second molding step: core temperature  5-60° C. mold cavity temperature  5-60° C. cycle time 20-35 seconds pressure 8000-15,000 psi [0019] The present invention will: be more particularly set forth in the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0020] FIGS. 1 A- 1 D are schematic illustrations of a first method embodiment of the present invention for making a preform having a full-length inner sleeve and a single outer layer; [0021] FIGS. 2 A- 2 B are schematic illustrations of an injection-molding apparatus and the sequence of operations for making a preform such as that shown in FIG. 1D, wherein a rotary turret transfers two sets of cores between two sets of cavities; FIG. 2A shows the cavities/cores in a closed position and FIG. 2B shows the cavities/cores in an open position; [0022] [0022]FIG. 3 is a time line showing the sequence of operations for the molding apparatus of FIG. 2; [0023] [0023]FIG. 4A is a front elevational view of a returnable and refillable container, partially in section, made from the preform of FIG. 1D, and FIG. 4B is an enlarged fragmentary cross-section of the container sidewall taken along the line 4 B- 4 B of FIG. 4A; [0024] FIGS. 5 A- 5 D are schematic illustrations of a second method embodiment of the present invention for making a preform having a finish only sleeve and a multilayer outer layer; [0025] FIGS. 6 A- 6 D are schematic illustrations of an injection-molding apparatus and sequence of operations for making a preform such as that shown in FIG. 5D, wherein the transfer mechanism is a reciprocating shuttle; FIG. 6A shows the shuttle in a first closed position in first and second mold cavities; FIG. 6B shows the shuttle in a second open position after retraction from the first and second mold cavities; FIG. 6C shows the shuttle in a second open position beneath the second and third mold cavities; and FIG. 6D shows the shuttle in a fourth closed position in the second and third mold cavities; [0026] [0026]FIG. 7 is a time line of the sequence of operations shown in FIG. 6; [0027] [0027]FIG. 8A is a cross-sectional view of a third preform embodiment of the present invention having a full-thickness neck sleeve and multilayer body portion, and FIG. 8B is an enlarged fragmentary view of the neck finish of the preform of FIG. 8A; [0028] [0028]FIG. 9A is a front elevational view of a hot-fill container made from the preform of FIG. 8A, and FIG. 9B is a fragmentary cross-section of the container sidewall taken along line 9 B- 9 B of FIG. 9A; [0029] [0029]FIG. 10 is a cross-sectional view of a fourth preform embodiment of the present invention, having a full-length body sleeve and multilayer outer layer; [0030] [0030]FIG. 11 is a cross-sectional view of a fifth preform embodiment of the present invention, including a full-length body sleeve and an extra outer base layer; [0031] [0031]FIG. 12 is a cross-sectional view of a sixth preform embodiment of the present invention, having a finish sleeve and a single layer outer layer; [0032] [0032]FIGS. 13A and 13B are graphs showing the change in melting temperature (MP) and orientation temperature (T g ) for various PEN/PET compositions; and [0033] [0033]FIG. 14 is a schematic illustration of a three-station reheating apparatus, including IR heating stations A and C and RF heating station B. DETAILED DESCRIPTION First Preform Embodiment (Refillable Water) [0034] FIGS. 1 A- 1 D illustrate schematically one method embodiment for making a preform with a full-length body sleeve and a single outer layer; this preform is particularly useful for making a returnable and refillable water bottle. FIG. 1A shows a first core 9 positioned in a first mold cavity 11 , and forming a chamber therebetween in which there is formed an injection-molded inner sleeve 20 . The sleeve 20 is partially cooled and then the core 9 carrying sleeve 20 is removed from the first mold cavity as shown in FIG. 1B. While still warm, the sleeve 20 on core 9 is inserted into a second mold cavity 12 which forms an interior molding chamber for forming an outer layer 22 over the inner sleeve 20 . After the second molding step, a preform 30 has been formed including outer layer 22 and inner sleeve 20 as shown in FIG. 1D. The inner sleeve includes a top flange 21 which will form the top sealing surface of the resulting container (see FIG. 4). [0035] The first method embodiment will now be described in greater detail in regard to the apparatus shown in FIGS. 2 A- 2 B, and a time sequence of operations illustrated in the time line of FIG. 3. [0036] As shown in FIGS. 2 A- 2 B, a four-sided rotatable turret 2 is interposed between a fixed platen 3 and a movable platen 4 on an injection-molding machine. The turret 2 is mounted on a carriage 5 which is slidable in the direction of platen motion (shown by arrows A 1 and A 2 ). The turret 2 is rotatable (shown by arrow A 3 ) about an axis 6 disposed perpendicular to the direction of platen motion. The turret is rotatable into two operative positions spaced 180° apart. In each of these positions, the two opposing faces 7 , 8 of the turret carrying first and second sets of cores 9 , 10 respectively, are received in a first set of cavities 11 on the movable platen 4 , and a second set of cavities 12 on the fixed platen 3 . After a core set has been successfully positioned in each of the mold cavities, the finished preforms may be ejected from the cores. Each of the mold cavity and core sets include water passages 15 for heating or cooling of the cavities/cores to achieve a desired temperature during molding. [0037] The sequence of operations for forming a particular preform will now be described. The preform has a full-body sleeve of a PEN polymer, such as homopolymer PEN, or a PEN/PET copolymer or blend. The preform has a single outer layer made of virgin PET. [0038] In FIG. 2A, the movable platen 4 carrying the first set of mold cavities 11 , and the carriage 5 carrying the turret 2 , are each moved on guide bars (tie rods) 13 , 14 to the left towards the fixed platen 3 to close the mold (i.e., both cavities). The first set of cores 9 on the left face 7 of the turret are positioned in the first cavity set 11 (first molding station); each first core/cavity pair defines an enclosed chamber for molding an inner sleeve about the first core. The PEN polymer is injected via nozzle 16 into the first mold cavities to form the inner sleeve. Simultaneously, the second core set 10 (on the second face 8 of the turret) is positioned in the second cavity set 12 (second molding station). Virgin PET is injected via nozzle 17 into the second set of cavities to form a single outer layer about a previously-formed inner sleeve on each of the second cores. [0039] Next, the mold is opened as shown in FIG. 2B by moving both the movable platen 4 and carriage 5 to the left, whereby the first cores 9 are removed from the first cavity 11 and the second cores 10 are removed from the second cavity 12 . Now, the finished preforms 30 on the second core set are ejected. The finished preforms 30 may be ejected into a set of robot cooling tubes (not shown) as is well known in the art. Next, the turret 2 is rotated 180°, whereby the first set of cores 9 with the inner sleeves 20 thereon are now on the right side of the turret (and ready for insertion into the second set of cavities), while the second set of (empty) cores 10 is now on the left side of the turret (ready for insertion into the first set of mold cavities). Again, the mold is closed as shown in FIG. 2A and injection of the polymer materials into the first and second sets of cavities proceeds as previously described. [0040] In this embodiment, the first and second cores are held at a temperature in a range on the order of 60-70° C., whether they are positioned in the first mold cavities or the second mold cavities. The first mold cavities (for forming the inner sleeve) are held at a temperature on the order of 85-95° C. The melt temperature of the PEN polymer is on the order of 285-295° C. The cycle time in the first mold cavity is on the order of 6-7 seconds, i.e., the time lapse between the first and second injections. This is because, as shown in FIG. 3, the hold and cool stage is substantially eliminated in the first mold cavities. The outer surface temperature of the sleeve (opposite the inner surface engaging the core) at the start of the second injection is 100-110° C. [0041] During the second molding step, the core temperature is again at 60-70° C., but the second mold cavity temperature is 5-10° C. (much lower than the first cavity temperature, to enable quick cooling of the preform). The melt temperature of the virgin PET is on the order of 260 to 275° C.; this is lower than the melt temperature of the PEN polymer, but because the PEN polymer is still warm (at a temperature of 100-110° C.) during the second molding step, there is melt adhesion (including diffusion bonding and chain entanglement) which occurs between the PEN polymer chains and virgin PET polymer chains (inner sleeve and outer layer) respectively. The cycle time for the second molding step is on the order of 35 to 37 seconds. [0042] [0042]FIG. 3 is a time line with the cycle time along the x axis (time in seconds), and the sequence of steps in the second cavity set shown above the x axis, and the sequence of steps in the first cavity set shown below the x axis. At t=0, the mold is closed (see FIG. 2A) and the pressure is built up. At t=1.5 seconds, the second cavity (for forming the outer layer) is filled, the pressure boosted, and then the pressure reduced during the hold and cooling stage; this continues until t=33 seconds in the second cavity. Meanwhile, no action is required at t=1.5 seconds in the first cavity (“no action period”); rather, it is not until t=31 seconds that the first cavity is filled and the pressure increased and held, until t=33 seconds. This substantial elimination of the hold and cooling stage (in the first cavity) produces an inner sleeve which is still at an elevated temperature when it is subsequently is positioned in the second cavity, and enables melt adhesion between the outer surface of the inner sleeve and outer layer. At t=33 seconds, the mold is opened (see FIG. 2B), and the preforms from the second cavity are ejected. Then, at t=35 seconds, the turret 2 is rotated so as to position the still-warm sleeves (just made in the first cavity) in a position to be inserted into the second cavity, while the now-empty core set (previously in the second cavity) is now positioned to be inserted in the first cavity. At t=36 seconds, we are ready to begin the next cycle. [0043] The method and apparatus of FIG. 2 may be advantageously used to produce multilayer preforms for a great variety of applications, including refill, hot-fill and pasteurizable containers. A number of alternative embodiments are described below. [0044] The preform made according to the method and apparatus of FIGS. 1 - 3 includes a full-body inner sleeve 20 of PEN polymer, and a single outer layer 22 of virgin PET. The preform is substantially transparent and amorphous and may be reheated and stretch blow-molded to form a 1.5 liter returnable and refillable water bottle, such as that shown in FIG. 4A. The container 40 is about 13.2 inches (335 mm) in height and about 3.6 inches (92 mm) in widest diameter. The container body has an open top end with a small diameter neck finish 42 having external screw threads for receiving a screw cap (not shown), and a closed bottom end or base 48 . Between the neck finish 42 and base 48 is a substantially vertically-disposed sidewall 45 (defined by vertical axis or centerline CL of the bottle), including a substantially cylindrical panel portion 46 and a shoulder portion 44 tapering in diameter from panel 45 to neck finish 42 . The base 48 is a champagne-style base with a central gate portion 51 and, moving radially outwardly towards the sidewall, an outwardly concave dome 52 , an inwardly concave chime 54 , and a radially increasing and arcuate outer base portion 56 for a smooth transition to the sidewall panel 46 . The chime 54 is a substantially toroidal-shaped area around a standing ring (chime) on which the bottle rests. [0045] [0045]FIG. 4B shows in cross-section the multilayer panel portion 46 , which includes an inner sleeve layer 41 (an expanded version of preform sleeve 20 ), and an outer layer 43 (an expanded version of preform outer layer 22 ). One benefit of the present invention is that the layers 41 and 43 have bonded and will not separate during reheat stretch blow molding or use of the container, in this case including the intended 20 or more refill cycles. In addition, a flange 47 (same as flange 21 of the preform) forms a top sealing surface of the container with increased strength and thermal resistance. Second Preform Embodiment (Pasteurizable Beer) [0046] FIGS. 5 A- 5 D illustrate schematically a second method embodiment for making a finish-only sleeve and a multiple outer layer preform; this preform is adapted for making a pasteurizable beer container. FIG. 5A shows a core 207 positioned in a first mold cavity 213 ; together they form a first molding chamber in which a finish-only sleeve 250 is injection molded. FIG. 5A shows an injection nozzle 211 in the mold cavity 213 , through which a molten thermoplastic material is injected for forming the sleeve 250 . FIG. 5B shows the formed sleeve 250 on the core 207 , the sleeve having been removed from first mold cavity 213 while it is still warm. The core 207 carrying the sleeve 250 is then positioned in a second mold cavity 214 as shown in FIG. 5C. The second mold cavity 214 and core 207 form a second molding chamber adapted to form an outer layer 252 over the inner sleeve 250 . A plurality of different thermoplastic materials are injected through a gate 209 in the bottom of the second mold cavity 214 , to form the multiple outer layers. As shown in FIG. 5D, the outer layer 252 extends the full length of the preform. A sequential injection process such as that described in U.S. Pat. No. 4,609,516 to Krishnakumar et al., may be used to form inner and outer layers 253 , 254 of virgin PET, core layer 255 of recycled PET (which may include an oxygen scavenging material), and inner and outer intermediate layers 256 , 257 of an oxygen barrier material, between the inner/core/outer layers. In this embodiment, only the virgin PET extends up into the neck finish of the preform, forming a single layer 258 over inner sleeve 250 . In the base of the preform, a final injection of virgin PET forms a plug 259 for clearing the nozzle before the next injection cycle. [0047] FIGS. 6 A- 6 D illustrate a reciprocating shuttle apparatus, instead of the rotatable turret of FIGS. 2 A- 2 D, which comprises a second apparatus embodiment. This second apparatus will now be described with respect to forming the preform of FIG. 5. FIG. 7 shows a time line of the sequence of operations. [0048] The apparatus (see FIGS. 6 A- 6 D) includes first and second parallel guide bars 202 , 203 on which a platen 205 is movably mounted in the direction of arrow A 4 . The platen 205 carries a platform or shuttle 206 which is movable in a transverse direction across the platen 205 as shown by arrow A 5 . A fixed platen 212 at one end of the guide bars holds three injection mold cavity sets 213 , 214 and 215 which are supplied by nozzles 218 , 219 and 220 respectively. The left (first) and right (third) cavity sets 213 and 215 are used to form neck portions of preforms, while the middle (second) cavity set 214 is used for molding body-forming portions. [0049] [0049]FIG. 5A shows an arbitrarily-designated first step wherein the first core set 207 is positioned in left cavity set 213 for forming a first set of preform neck portions (sleeves). Simultaneously, second core set 208 is positioned in middle cavity set 214 for molding a set of multilayer body-forming portions (over a second set of previously molded neck portions). FIG. 5B shows the core sets following removal from the cavity sets, with a neck sleeve 250 on each core of core set 207 , and a preform 260 on each core of core set 208 . The completed preforms 260 are then ejected from the core set 208 . [0050] In a second step (FIG. 6C), the shuttle 206 is moved to the right such that the first core set 207 with neck sleeves 250 are now positioned below middle cavity 214 , while second core set 208 with now empty cores 216 is positioned below right cavity set 215 . Movable platen 205 is then moved towards fixed platen 212 so as to position first core set 207 in middle cavity set 214 , and second core set 208 in right cavity set 215 (FIG. 6D). Again, body-forming portions are formed over the previously formed neck sleeves in middle cavity set 214 , while neck sleeves are molded on each of the cores in the core set 208 in right cavity set 215 . The movable platen 205 is then retracted to remove the core sets from the cavity sets, the finished preforms on the first core set 207 are ejected, and the shuttle 206 returns to the left for molding the next set of layers. [0051] [0051]FIG. 7 is a time line of the operations shown in FIG. 6, with time in seconds along the x axis, and the sequence of steps in the second cavity 214 shown above the x axis, and the sequence of steps in the first cavity 213 shown below the x axis. First, at t=0, the mold is closed (FIG. 6A) and the pressure builds up. Then, at t=1.5 seconds, the second cavity 214 is filled (forming the outer layer), the pressure increased, and the pressure held while the preform cools, until t=21 seconds. Meanwhile, no action is required in the first cavity at t=1.5 seconds. at t=20 seconds, the first cavity 213 is filled with PEN polymer and the pressure increased and held until t=21 seconds (again the hold and cooling stage has been substantially eliminated in the first cavity set by delaying the filling stage until near the end of the hold and cooling stage for the second cavity set). At t=21 seconds, the mold is opened and the preforms 260 are ejected from the second cavities. At t=23 seconds, the shuttle 206 with the still warm neck sleeves is transferred to the second shuttle position as shown in FIG. 6C, and at t=24 seconds the mold is closed as shown in FIG. 6D. [0052] In this particular embodiment, the first and second core sets 207 , 208 are held at a temperature on the order of 60-70° C. during both of the first and second molding steps. The first mold cavity (for forming the neck finish sleeve) is on the order of 75-85° C. The PEN polymer has a melt temperature on the order of 275-285° C. The cycle time in the first cavity is on the order of 5-6 seconds; this is the time lapse between the first and second injection steps. The surface temperature of the sleeve at the time of the second injection is on the order of 100-110° C. [0053] In the second molding step, the core temperature is on the order of 60-70° C., and the second mold cavity is at a temperature on the order of 5-10° C. The cycle time in the second mold cavity is on the order of 23-25 seconds. The elevated temperature at the outer surface of the sleeve, at the time of the second molding step, causes melt adhesion (including diffusion bonding and chain entanglement) between the PEN polymer of the sleeve and the virgin PET of the outer layer portion 258 which is adjacent the sleeve 250 . Third Preform Embodiment (Hot Fill) [0054] A further preform/container embodiment is illustrated in FIGS. 8 - 9 . FIGS. 8 A- 8 B show a multilayer preform 330 and FIGS. 9 A- 9 B show a hot-fill beverage bottle 370 made from the preform of FIG. 8. In this embodiment, a first molded sleeve forms the entire thickness of the neck finish, and is joined at its lower end to a second molded body-forming portion. [0055] [0055]FIG. 8A shows a substantially cylindrical preform 330 (defined by vertical centerline 332 ) which includes an upper neck portion or finish sleeve 340 bonded to a lower body-forming portion 350 . The crystallized neck portion is a monolayer of CPET and includes an upper sealing surface 341 which defines the open top end 342 of the preform, and an exterior surface having threads 343 and a lowermost flange 344 . CPET, sold by Eastman Chemical, Kingsport, Tenn., is a polyethylene terephthalate polymer with nucleating agents which cause the polymer to crystallize during the injection molding process. Below the neck finish 340 is a body-forming portion 350 which includes a flared shoulder-forming section 351 , increasing (radially inwardly) in wall thickness from top to bottom, a cylindrical panel-forming section 352 having a substantially uniform wall thickness, and a base-forming section 353 . Body-forming section 350 is substantially amorphous and is made of the following three layers in serial order: outer layer 354 of virgin PET; core layer 356 of post-consumer PET; and inner layer 358 of virgin PET. The virgin PET is a low copolymer having 3% comonomers (e.g., cyclohexane dimethanol (CHDM) or isophthalic acid (IPA)) by total weight of the copolymer. A last shot of virgin PET (to clean the nozzle) forms a core layer 359 in the base. [0056] This particular preform is designed for making a hot-fill beverage container. In this embodiment, the preform has a height of about 96.3 mm, and an outer diameter in the panel-forming section 352 of about 26.7 mm. The total wall thickness at the panel-forming section 352 is about 4 mm, and the thicknesses of the various layers are: outer layer 354 of about 1 mm, core layer 356 of about 2 mm, and inner layer 358 of about 1 mm. The panel-forming section 352 may be stretched at an average planar stretch ratio of about 10:1, as described hereinafter. The planar stretch ratio is the ratio of the average thickness of the preform panel-forming portion 352 to the average thickness of the container panel 383 , wherein the “average” is taken along the length of the respective preform or container portion. For hot-fill beverage bottles of about 0.5 to 2.0 liters in volume and about 0.35 to 0.60 millimeters in panel wall thickness, a preferred planar stretch ratio is about 9 to 12, and more preferably about 10 to 11. The hoop stretch is preferably about 3.3 to 3.8 and the axial stretch about 2.8 to 3.2. This produces a container panel with the desired abuse resistance, and a preform sidewall with the desired visual transparency. The specific panel thickness and stretch ratio selected depend on the dimensions of the bottle, the internal pressure, and the processing characteristics (as determined for example, by the intrinsic viscosity of the particular materials employed). [0057] In order to enhance the crystallinity of the neck portion, a high injection mold temperature is used at the first molding station. In this embodiment, CPET resin at a melt temperature of about 280 to 290° C. is injection molded at a mold cavity temperature of about 110 to 120° C. and a core temperature of about 5 to 15° C., and a cycle time of about 6 to 7 seconds. The first core set, carrying the still warm neck portions (outer surface temperature of about 115 to 125° C.), are then transferred to the second station where multiple second polymers are injected to form the multilayer body-forming portions and melt adhesion occurs between the neck and body-forming portions. The core and/or cavity set at the second station are cooled (e.g., 5 to 15° C. core/cavity temperature) in order to solidify the performs and enable removal from the molds (cycle time of about 23 to 25 seconds) with acceptable levels of post-mold shrinkage. The cores and cavities at both the first and second stations include water cooling/heating passages for adjusting the temperature as desired. [0058] As used herein, “melt adhesion” between the inner sleeve and outer layer is meant to include various types of bonding which occur due to the enhanced temperature (at the outer surface of the inner sleeve) and pressure (e.g., typical injection molding on the order of 8,000-15,000 psi) during the second molding step, which may include diffusion, chemical, chain entanglement, hydrogen bonding, etc. Generally, diffusion and/or chain entanglement will be present to form a bond which prevents delamination of the layers in the preform, and in the container when filled with water at room temperature (25° C.) and dropped from a height of eighteen inches onto a thick steel plate. [0059] [0059]FIG. 8B is an expanded view of the neck finish 340 of preform 330 . The monolayer CPET neck finish is formed with a projection 345 at its lower end, which is later surrounded (interlocked) by the virgin PET melt from the inner and outer layers 354 , 358 at the second molding station. The CPET neck finish and outermost virgin PET layers of the body are melt adhered together in this intermediate region (between the lower end of the neck finish sleeve and the upper end of the body-forming region). [0060] [0060]FIG. 9A shows a unitary expanded plastic preform container 370 , made from the preform of FIG. 8. The container is about 182.0 mm in height and about 71.4 mm in (widest) diameter. This 16-oz. container is intended for use as a hot-fill non-carbonated juice container. The container has an open top end with the same crystallized neck finish 340 as the preform, with external screw threads 343 for receiving a screw-on cap (not shown). Below the neck finish 340 is a substantially amorphous and transparent expanded body portion 380 . The body includes a substantially vertically-disposed sidewall 381 (defined by vertical centerline 372 of the bottle) and base 386 . The sidewall includes an upper flared shoulder portion 382 increasing in diameter to a substantially cylindrical panel portion 383 . The panel 383 has a plurality of vertically-elongated, symmetrically-disposed vacuum panels 385 . The vacuum panels move inwardly to alleviate the vacuum formed during product cooling in the sealed container, and thus prevent permanent, uncontrolled deformation of the container. The base 386 is a champagne-style base having a recessed central gate portion 387 and moving radially outwardly toward the sidewall, an outwardly concave dome 388 , an inwardly concave chime 389 , and a radially increasing and arcuate outer base portion 390 for a smooth transition to the sidewall 381 . [0061] [0061]FIG. 9B shows in cross section the multilayer panel portion 383 including an outer layer 392 , a core layer 394 . and an inner layer 396 , corresponding to the outer 354 , core 356 and inner 358 layers of the preform. The inner and outer container layers 392 , 396 (of virgin PET copolymer) are each about 0.1 mm thick, and the core layer 394 (of post-consumer PET) is about 0.2 mm thick. The shoulder 382 and base 386 are stretched less and therefore are relatively thicker and less oriented than the panel 383 . Fourth Preform Embodiment [0062] A fourth preform embodiment is illustrated in FIG. 10. A multilayer preform 130 is made from the method and apparatus of FIGS. 1 - 2 , and is adapted to be reheat stretch blow-molded into a refillable carbonated beverage bottle similar to that shown in FIG. 4, but having a thickened base area including the chime for increased resistance to caustic and pressure induced stress cracking. [0063] In FIG. 10 there is shown a preform 130 which includes a PEN inner sleeve layer 120 , and a three-layer outer layer comprising outermost (exterior) virgin PET layer 123 , first intermediate (interior) PC-PET layer 124 , and second intermediate (interior) virgin PET layer 125 . The inner sleeve layer 120 is continuous, having a body portion 121 extending the full length of the preform and throughout the base. The sleeve layer further includes an upper flange 122 which forms the top sealing surface of the preform. The outer layer similarly extends the full length and throughout the bottom of the preform. [0064] The preform 130 includes an upper neck finish 132 , a flared shoulder-forming section 134 which increases in thickness from top to bottom, a panel-forming section 136 having a uniform wall thickness, and a thickened base-forming section 138 . Base section 138 includes an upper cylindrical thickened portion 133 (of greater thickness than the panel section 136 ) which forms a thickened chime in the container base, and a tapering lower portion 135 of reduced thickness for forming a recessed dome in the container base. A last shot of virgin PET (to clean the nozzle) forms a core layer 139 in the base. A preform having a preferred cross-section for refill applications is described in U.S. Pat. No. 5,066,528 granted Nov. 19, 1991 to Krishnakumar et al., which is hereby incorporated by reference in its entirety. [0065] This particular preform is designed for making a refillable carbonated beverage container. The use of an inner sleeve 120 of a PEN homopolymer, copolymer, or blend provides reduced flavor absorption and increased thermal stability for increasing the wash temperature. The inner PEN sleeve can be made relatively thin according to the method of FIG. 1. The interior PC-PET layer 124 can be made relatively thick to reduce the cost of the container, without significantly affecting performance. In this example, the preform has a height of about 7.130 inches (181.1 mm), and an outer diameter in the panel-forming section 136 of about 1.260 inches (32.0 mm). At the panel-forming section 136 , the total wall thickness is about 0.230 inches (5.84 mm), and the thicknesses of the various layers are: inner layer 120 of about 0.040 inches (1.0 mm), outermost layer 123 of about 0.040 inches (1.0 mm), first intermediate layer 124 of about 0.130 inches (3.30 mm), and second intermediate layer 125 of about 0.020 inches (0.5 mm). The panel-forming section 136 may be stretched at an average planar stretch ratio of about 10.5:1, as described hereinafter. The planar stretch ratio is the ratio of the average thickness of the preform panel-forming portion 136 to the average thickness of the container panel (see for example sidewall 46 in FIG. 4), wherein the “average” is taken along the length of the respective preform or container portion. For refillable carbonated beverage bottles of about 0.5 to 2.0 liters in volume and about 0.5 to 0.8 millimeters in panel wall thickness, a preferred planar stretch ratio is about 7.5-10.5, and more preferably about 9.0-10.5. The hoop stretch is preferably about 3.2-3.5 and the axial stretch about 2.3-2.9. This produces a container panel with the desired abuse resistance, and a preform sidewall with the desired visual transparency. The specific panel thickness and stretch ratio selected depend on the dimensions of the bottle, the internal pressure (e.g., 2 atmospheres for beer and 4 atmospheres for soft drinks), and the processing characteristics (as determined for example, by the intrinsic viscosity of the particular materials employed). [0066] In order to provide a thin PEN sleeve layer (e.g. 0.5 to 1.0 mm), a suitable mold cavity temperature would be on the order of 100 to 110° C. and core temperature of about 5 to 15° C., for a PET melt temperature of about 285 to 295° C. and cycle time of about 6 to 7 seconds. The first core set and warm inner layer are then immediately transferred to the second station where the outer layers are injected and bonding occurs between the inner and outer layers (e.g., exterior surface of inner PEN sleeve layer at about 90 to 100° C. and innermost PET layer at about 260 to 275° C.). The first core set and/or second cavity set at the second station are cooled (e.g., about 5 to 15° C.) in order to solidify the perform and enable removal from the mold. The cores and cavities at both the first and second stations include water cooling/heating passages for adjusting the temperature as desired. [0067] In this embodiment, the inner sleeve layer 120 is made from a high-PEN copolymer having 90% PEN/10% PET by total weight of the layer, and in the container panel is about 0.004 inches (0.10 mm) thick. The outermost layer 123 is a virgin PET low copolymer having 3% comonomers (e.g., CHDM or IPA), and in the container panel is about 0.004 in (0.10 mm) thick. The first intermediate layer 124 is PC-PET, and in the container panel is about 0.012 in (0.30 mm) thick. The second intermediate layer 125 is the same virgin PET low copolymer as outermost layer 123 , and in the container panel is about 0.002 in (0.05 mm) thick. The container shoulder and base (see 44 and 48 in FIG. 4A) are stretched less and therefore are thicker and less oriented than the panel (see 46 in FIG. 4A). Fifth Preform Embodiment [0068] [0068]FIG. 11 illustrates another preform embodiment for making a refillable carbonated beverage container. This preform has an additional outermost layer in the base only for increasing caustic stress crack resistance, while maximizing the use of post-consumer PET for reducing the cost. The preform 160 includes an upper neck finish 162 , shoulder-forming portion 164 , panel-forming section 166 , and base-forming portion 168 . The inner layer 170 has a body portion 171 which is continuous throughout the length (including the bottom) of the preform and includes an upper flange 172 forming the top sealing surface. The inner layer is virgin PET. An outer layer 173 of PC-PET extends throughout the length of the preform, and forms a single outer layer in the neck finish and panel-forming section. In the base-forming portion an additional exterior layer 174 of high IV virgin PET is provided to enhance the caustic stress crack resistance of the blown container. A thin interior layer 175 of the high IV virgin PET may also be formed according to the sequential injection process previously referenced. A last shot 176 of high IV virgin PET is used to clear out the PC-PET from the nozzle section. The outer base layer 174 is preferably a high IV virgin PET (homopolymer or copolymer) having an intrinsic viscosity of at least about 0.76, and preferably in the range of 0.76 to 0.84. The resulting container may be either a footed or champagne base container. Sixth Preform Embodiment [0069] [0069]FIG. 12 shows another preform embodiment including a high-temperature neck finish sleeve 190 and a single outer layer 194 for forming a hot-fill container. The preform 180 includes a neck finish 182 , shoulder-forming portion 184 , panel-forming portion 186 , and base-forming portion 188 . The inner sleeve 190 includes a neck finish portion 191 , extending substantially along the length of the upper threaded neck finish portion 182 of the container, and an upper flange 192 forming a top sealing surface. The inner sleeve is formed of a thermal resistant (high T g ) material such as a PEN homopolymer, copolymer or blend. Alternatively, the sleeve may be formed of CPET, sold by Eastman Chemical, Kingsport, Tenn, a polyethylene terephthalate polymer with nucleating agents which cause the polymer to crystallize during the injection molding process. [0070] The outer layer 194 is made of virgin PET. This preform is intended for making hot-fill containers, wherein the inner sleeve 190 provides additional thermal stability at the neck finish. [0071] In further alternative embodiments, a triple outer layer of virgin PET, PC-PET, and virgin PET may be used. [0072] Alternative Constructions and Materials [0073] There are numerous preform and container constructions, and many different injection moldable materials, which may be adapted for a particular food product and/or package, filling, and manufacturing process. Additional representative examples are given below. [0074] Thermoplastic polymers useful in the present invention include polyesters, polyamides and polycarbonates. Suitable polyesters include homopolymers, copolymers or blends of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polypropylene terephthalate (PPT), polyethylene napthalate (PEN), and a cyclohexane dimethanol/PET copolymer, known as PETG (available from Eastman Chemical, Kingsport, Tenn.). Suitable polyamides (PA) include PA6, PA6,6, PA6,4, PA6,10, PA11, PA12, etc. Other useful thermoplastic polymers include acrylic/imide, amorphous nylon, polyacrylonitrile (PAN), polystyrene, crystallizable nylon (MXD-6), polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC). [0075] Polyesters based on terephthalic or isophthalic acid are commercially available and convenient. The hydroxy compounds are typically ethylene glycol and 1,4-di-(hydroxy methyl)-cyclohexane. The intrinsic viscosity for phthalate polyesters are typically in the range of 0.6 to 1.2, and more particularly 0.7 to 1.0 (for O-chlorolphenol solvent). 0.6 corresponds approximately to a viscosity average molecular weight of 59,000, and 1.2 to a viscosity average molecular weight of 112,000. In general, the phthalate polyester may include polymer linkages, side chains, and end groups not related to the formal precursors of a simple phthalate polyester previously specified. Conveniently, at least 90 mole percent will be terephthalic acid and at least 90 mole percent an aliphatic glycol or glycols, especially ethylene glycol. [0076] Post-consumer PET (PC-PET) is a type of recycled PET prepared from PET plastic containers and other recyclables that are returned by consumers for a recycling operation, and has now been approved by the FDA for use in certain food containers. PC-PET is known to have a certain level of I.V. (intrinsic viscosity), moisture content, and contaminants. For example, typical PC-PET (having a flake size of one-half inch maximum), has an I.V. average of about 0.66 dl/g, a relative humidity of less than 0.25%, and the following levels of contaminants: [0077] PVC: <100 ppm [0078] aluminum: <50 ppm [0079] olefin polymers (HDPE, LDPE, PP): <500 ppm [0080] paper and labels: <250 ppm [0081] colored PET: <2000 ppm [0082] other contaminants: <500 ppm [0083] PC-PET may be used alone or in one or more layers for reducing the cost or for other benefits. [0084] Also useful as a base polymer or as a thermal resistant and/or high-oxygen barrier layer is a packaging material with physical properties similar to PET, namely polyethylene naphthalate (PEN). PEN provides a 3-5× improvement in barrier property and enhanced thermal resistance, at some additional expense. Polyethylene naphthalate (PEN) is a polyester produced when dimethyl 2,6-naphthalene dicarboxylate (NDC) is reacted with ethylene glycol. The PEN polymer comprises repeating units of ethylene 2,6 naphthalate. PEN resin is available having an inherent viscosity of 0.67 dl/g and a molecular weight of about 20,000 from Amoco Chemical Company, Chicago, Ill. PEN has a glass transition temperature T g of about 123° C., and a melting temperature T m of about 267° C. [0085] Oxygen barrier layers include ethylene/vinyl alcohol (EVOH), PEN, polyvinyl alcohol (PVOH), polyvinyldene chloride (PVDC), nylon 6, crystallizable nylon (MXD-6), LCP (liquid crystal polymer), amorphous nylon, polyacrylonitrile (PAN) and styrene acrylonitrile (SAN). [0086] The intrinsic viscosity (I.V.) effects the processability of the resins. Polyethylene terephthalate having an intrinsic viscosity of about 0.8 is widely used in the carbonated soft drink (CSD) industry. Polyester resins for various applications may range from about 0.55 to about 1.04, and more particularly from about 0.65 to 0.85dl/g. Intrinsic viscosity measurements of polyester resins are made according to the procedure of ASTM D-2857, by employing 0.0050±0.0002 g/ml of the polymer in a solvent comprising o-chlorophenol (melting point 0° C.), respectively, at 30° C. Intrinsic viscosity (I.V.) is given by the following formula: I.V. =( ln ( V Soln. /V Sol. ))/ C [0087] where: [0088] V Soln. is the viscosity of the solution in any units; [0089] V Sol. is the viscosity of the solvent in the same units; and [0090] C is the concentration in grams of polymer per 100 mls of solution. [0091] The blown container body should be substantially transparent. One measure of transparency is the percent haze for transmitted light through the wall (H T ) which is given by the following formula: H T =[Y d ÷( Y d +Y s )]×100 [0092] where Y d is the diffuse light transmitted by the specimen, and Y s is the specular light transmitted by the specimen. The diffuse and specular light transmission values are measured in accordance with ASTM Method D 1003, using any standard color difference meter such as model D25D3P manufactured by Hunterlab, Inc. The container body should have a percent haze (through the panel wall) of less than about 10%, and more preferably less than about 5%. [0093] The preform body-forming portion should also be substantially amorphous and transparent, having a percent haze across the wall of no more than about 10%, and more preferably no more than about 5%. [0094] The container will have varying levels of crystallinity at various positions along the height of the bottle from the neck finish to the base. The percent crystallinity may be determined according to ASTM 1505 as follows: % crystallinity=[( ds−da )/( dc−da )]×100 [0095] where ds=sample density in g/cm 3 , da=density of an amorphous film of zero percent crystallinity, and dc=density of the crystal calculated from unit cell parameters. The panel portion of the container is stretched the greatest and preferably has an average percent crystallinity in at least the outer layer of at least about 15%, and more preferably at least about 20%. For primarily PET polymers, a 15-25% crystallinity range is useful in refill and hot-fill applications. [0096] Further increases in crystallinity can be achieved by heat setting to provide a combination of strain-induced and thermal-induced crystallization. Thermal-induced crystallinity is achieved at low temperatures to preserve transparency, e.g., holding the container in contact with a low temperature blow mold. In some applications, a high level of crystallinity at the surface of the sidewall alone is sufficient. [0097] As a further alternative embodiment, the preform may include one or more layers of an oxygen scavenging material. Suitable oxygen scavenging materials are described in U.S. Ser. No. 08/355,703 filed Dec. 14, 1994 by Collette et al., entitled “Oxygen Scavenging Composition For Multilayer Preform And Container,” which is hereby incorporated by reference in its entirety. As disclosed therein, the oxygen scavenger may be a metal-catalyzed oxidizable organic polymer, such as a polyamide, or an anti-oxidant such as phosphite or phenolic. The oxygen scavenger may be mixed with PC-PET to accelerate activation of the scavenger. The oxygen scavenger may be advantageously combined with other thermoplastic polymers to provide the desired injection molding and stretch blow molding characteristics for making substantially amorphous injection molded preforms and substantially transparent biaxially oriented polyester containers. The oxygen scavenger may be provided as an interior layer to retard migration of the oxygen scavenger or its byproducts, and to prevent premature activation of the scavenger. [0098] Refillable containers must fulfill several key performance criteria in order to achieve commercial viability, including: [0099] 1. high clarity (transparency) to permit visual on-line inspection; [0100] 2. dimensional stability over the life of the container; and [0101] 3. resistance to caustic wash induced stress cracking and leakage. [0102] Generally, a refillable plastic bottle must maintain its functional and aesthetic characteristics over a minimum of 10 and preferably 20 cycles or loops to be economically feasible. A cycle is generally comprised of (1) an empty hot caustic wash, (2) contaminant inspection (before and/or after wash) and product filling/capping, (3) warehouse storage, (4) distribution to wholesale and retail locations and (5) purchase, use and empty storage by the consumer, followed by eventual return to the bottler. [0103] A test procedure for simulating such a cycle would be as follows. As used in this specification and claims, the ability to withstand a designated number of refill cycles without crack failure and/or with a maximum volume change is determined according to the following test procedure. [0104] Each container is subjected to a typical commercial caustic wash solution prepared with 3.5% sodium hydroxide by weight and tap water. The wash solution is maintained at a designated wash temperature, e.g., 60° C. The bottles are submerged uncapped in the wash for 15 minutes to simulate the time/temperature conditions of a commercial bottle wash system. After removal from the wash solution, the bottles are rinsed in tap water and then filled with a carbonated water solution at 4.0±0.2 atmospheres (to simulate the pressure in a carbonated soft drink container), capped and placed in a 38° C. convection oven at 50% relative humidity for 24 hours. This elevated oven temperature is selected to simulate longer commercial storage periods at lower ambient temperatures. Upon removal from the oven, the containers are emptied and again subjected to the same refill cycle, until failure. [0105] A failure is defined as any crack propagating through the bottle wall which results in leakage and pressure loss. Volume change is determined by comparing the volume of liquid the container will hold at room temperature, both before and after each refill cycle. [0106] A refillable container can preferably withstand at least 20 refill cycles at a wash temperature of 60° C. without failure, and with no more than 1.5% volume change after 20 cycles. [0107] In this invention, a higher level of crystallization can be achieved in the neck finish compared to prior art processes which crystallize outside the mold. Thus, the preform neck finish may have a level of crystallinity of at least about 30%. As a further example, a neck finish made of a PET homopolymer can be molded with an average percent crystallinity of at least about 35%, and more preferably at least about 40% To facilitate bonding between the neck portion and body-forming portion of the preform, one may use a thread split cavity, wherein the thread section of the mold is at a temperature above 60° C., and preferably above 75° C. [0108] As an additional benefit, a colored neck finish can be produced, while maintaining a transparent container body. [0109] The neck portion can be monolayer or multilayer and made of various polymers other than CPET, such as arylate polymers, polyethylene naphthalate (PEN), polycarbonates, polypropylene, polyimides, polysulfones, acrylonitrile styrene, etc. As a further alternative, the neck portion can be made of a regular bottle-grade homopolymer or low copolymer PET (i.e., having a low crystallization rate), but the temperature or other conditions of the first molding station can be adjusted to crystallize the neck portion. [0110] Other benefits include the achievement of higher hot-fill temperatures (i.e., above 85° C.) because of the increased thermal resistance of the finish, and higher refill wash temperatures (i.e., above 60° C.). The increased thermal resistance is also particularly useful in pasteurizable containers. [0111] FIGS. 13 A- 13 B illustrate graphically the change in melt temperature and orientation temperature for PET/PEN compositions, as the weight percent of PEN increases from 0 to 100. There are three classes of PET/PEN copolymers or blends: (a) a high-PEN concentration having on the order of 80-100% PEN and 0-20% PET by total weight of the copolymer or blend, which is a strain-hardenable (orientable) and crystallizable material; (b) a mid-PEN. concentration having on the order of 20-80% PEN and 80-20% PET, which is an amorphous non-crystallizable material that will not undergo strain hardening; and (c) a low-PEN concentration having on the order of 1-20% PEN and 80-99% PET, which is a crystallizable and strain-hardenable material. A particular PEN/PET polymer or blend can be selected from FIGS. 13 A- 13 B based on the particular application. [0112] [0112]FIG. 14 illustrates a particular embodiment of a combined infrared (IR) and radio frequency (RF) heating system for reheating previously molded and cooled preforms (i.e., for use in a two-stage reheat injection mold and stretch blow process). This system is intended for reheating preforms having layers with substantially different orientation temperatures. For example, in the fourth preform embodiment the high-PEN inner layer 120 has an orientation temperature much higher than the virgin PET low copolymer and PC-PET outer layers 123 - 125 . PEN homopolymer has a minimum orientation temperature on the order of 260° F. (127° C.), based on a glass transition temperature on the order of 255° F. (123° C.). PEN homopolymer has a preferred orientation range of about 270-295° F. (132-146° C.). In contrast, PET homopolymer has a glass transition temperature on the order of 175° F. (80° C.). At the minimum orientation temperature of PEN homopolymer, PET homopolymer would begin to crystallize and would no longer undergo strain hardening (orientation), and the resulting container would be opaque and have insufficient strength. [0113] Returning to FIG. 14, this combined reheating apparatus may be used with preforms having a substantial disparity in orientation temperatures between layers. The preforms 130 are held at the upper neck finish by a collet 107 and travel along an endless chain 115 through stations A, B and C in serial order. Station A is a radiant heating oven in which the preforms are rotated while passing by a series of quartz heaters. The heating of each preform is primarily from the exterior surface and heat is transmitted across the wall to the inner layer. The resulting heat or temperature profile is higher at the exterior surface of the preform than at the interior surface. The time and temperature may be adjusted in an attempt to equilibriate the temperature across the wall. [0114] In this embodiment, it is desired to heat the inner PEN layer at a higher temperature because of PEN's higher orientation temperature. Thus, the preforms (across the wall) are brought up to an initial temperature of about 160° F. (71° C.) at station A, and are then transferred to station B which utilizes microwave or radio frequency heaters. These high-frequency dielectric heaters provide a reverse temperature profile from that of the quartz heaters, with the interior surface of the preform being heated to a higher temperature than that of the exterior surface. FIG. 14 shows the preforms 130 traveling between electrode plates 108 and 109 , which are connected to RF generator 110 and ground respectively. At station B, the inner layer is brought up to a temperature of about 295° F. (146° C.), and the outer layer to a temperature of about 200° F. (93° C.). Finally, the preforms are passed to station C, which is similar to station A. At station C the quartz heaters bring the preforms to a temperature of about 280° F. (138° C.) at the inner layer and about 210° F. (99° C.) at the outer layer. The reheated preforms are then sent to a blow mold for stretch blow molding. A more detailed description of hybrid reheating of polyester preforms including a combination of quartz oven reheating and radio frequency reheating is described in U.S. Pat. No. 4,731,513 to Collette entitled “Method Of Reheating Preforms For Forming Blow Molded Hot Fillable Containers,” which issued Mar. 15, 1988, and is hereby incorporated by reference. In addition, additives may be provided in either or both of the PET and PEN layers to make them more receptive to radio frequency heating. [0115] In a preferred thin sleeve/thick outer layer embodiment, the thin inner layer sleeve may have a thickness on the order of 0.02 to 0.06 inch (0.5 to 1.5 mm), while the thick outer layer has a wall thickness on the order of 0.10 to 0.25 inch (2.50 to 6.35 mm). The inner layer may comprise on the order of 10-20% by total weight of the preform. This represents an improvement over the prior art single injection cavity process for making multilayer preforms. Also, the weight of one or more outer layers (such as a layer of PC-PET) can be maximized. [0116] While there have been shown and described several embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined by the appending claims.

Sleeve molding apparatus and methods for making multi-layer injection molded plastic articles in successive mold cavities. In a first molding step, an inner sleeve is molded on a core in a first mold cavity, which may comprise a full body length sleeve or only a partial sleeve, such as an upper neck finish portion. The sleeve and core are withdrawn from the first mold cavity while the sleeve is still warm, and transferred without substantial delay to a second mold cavity for injection molding an outer layer which bonds to the inner sleeve. By transferring the sleeve at an elevated temperature into the second mold cavity, an improved bond is formed between the inner sleeve and outer layer which resists separation during a later reheat stretch blow molding step, and/or in use of the resulting article. In a preferred embodiment, a pasteurizable beer container is provided having a finish-only sleeve of a PEN polymer. In a second embodiment, a returnable and refillable water container is provided having a full-length body sleeve of a PEN polymer. A multi-station injection molding apparatus is provided having a transfer mechanism, such as a rotatable turret or reciprocating shuttle, for cost-effective manufacture of preforms simultaneously in multiple cavity sets.

FIELD OF THE INVENTION [0001] This application generally relates to systems and methods for authenticating a bulk quantity of a consumable product with a corresponding product. More specifically, the invention associates a bulk quantity of the consumable product with a product parameter such as a consumption rate of the consumable product within the corresponding product; provides and authorizes a key and/or reader with the bulk quantity and consumption rate data to a specific corresponding product wherein the bulk quantity and consumption rate data are correlated to a maximum consumption quantity value; monitoring consumption of the consumable product within the corresponding product until the maximum consumption quantity value is reached; and providing an event output to the corresponding product when the maximum consumption quantity value is realized. BACKGROUND OF THE INVENTION [0002] In today's competitive marketplace, the costs for companies to create, maintain, and grow new markets and market share is becoming increasingly expensive. Providing low cost systems of assuring the company's investment is protected by newcomers into the market place is increasing in demand. Previous systems of differentiating the authenticity of a product have generally focused on individual pieces. That is, if a manufacturer wants to ensure that a specific refill or consumable product (eg. a printer toner cartridge or a soap refill) is configured to specific equipment, that is the primary or corresponding product (eg. a printer or soap dispenser), each refill product will be individually provided with the authentication system that allows the refill product to be used with the primary product. [0003] In cases where the individual consumable pieces are inexpensive or that have a physical shape that does not readily permit the inclusion of authentication systems, present authentication techniques are difficult to implement or are too expensive to justify the costs. For example, if the refill product is only worth a few pennies, the cost of incorporating an authentication system that may cost at least a few pennies to incorporate with the refill product cannot usually be justified. [0004] Furthermore, for these types of products, as with other products that are readily marked, there has also been a need to enhance brand protection, to monitor and maintain shelf-life requirements and best-before dates, limit the life of a material, ensure non-compatible products are not used inappropriately for safety considerations, as well as for distribution control and prevention of cross selling into markets. [0005] As described in co-pending application PCT/CA2011/001008, authentication technologies having electronic keying that utilize special optical coatings are effective and inexpensive methods of being able to differentiate between authentic products and counterfeit products on an individual basis. As described in PCT '008, individual products can be linked or keyed to a specific dispensing product using inexpensive LED emitters/receivers and special optical coatings. However, the PCT '008 technology generally requires that the two products are in close proximity to one another in order for the keying to be enabled and can thus be limited by a number of factors including the geometric limitations of the consumable and corresponding products. [0006] In other words, and by way of example, with regards to bulk products, there has been a need for a system that enables the consumption of bulk products to be monitored without the need for marking each specific item. For example, it is more difficult and potentially expensive to mark individual hot drink stir sticks that may be used with a commercial stir stick dispenser. However, as is known, stir sticks are generally packaged and shipped in larger containers/boxes that may contain several hundred dozen individual sticks. As such, specifically keying individual stir sticks to a dispenser is difficult or impractical. [0007] Thus, there is a need for an authentication system and methodology that is capable of and that is inexpensive enough to authenticate a wider range of products including odd-shaped and inexpensive products. [0008] Further still, there has been a need for product authentication systems that can be readily retro-fit to existing equipment, such that existing equipment can be effective in ensuring that properly authenticated consumable products are used within the existing equipment without the need for extensive modifications to the existing equipment. [0009] Further still, there has been a need for systems that can effectively monitor the consumption of product across a number of different pieces of equipment. SUMMARY OF THE INVENTION [0010] In accordance with the invention, there is provided a method of authenticating a bulk quantity of a consumable product with a corresponding product that utilizes the consumable product comprising the steps of: (a) associating a bulk quantity of the consumable product with a consumption parameter of the consumable product within the corresponding product; (b) authorizing a key with the bulk quantity and consumption parameter from step a) to a specific corresponding product wherein the bulk quantity and consumption parameter are correlated to a quantity value; (c) monitoring consumption of the consumable product within the corresponding product until the quantity value is reached; and (d) providing an event output to the corresponding product when the quantity value is realized. [0011] In various embodiments, the event output is an audio and/or visual signal to an end-user; and/or the quantity value is any one of or a combination of total volume, total mass or time. [0012] In another embodiment, the method further includes the step of altering the operation of the corresponding product when the quantity value is reached which may include increasing the amount of material being dispensed when the quantity value is reached, decreasing the amount of material being dispensed when the quantity value is reached or stopping the amount of material being dispensed when the quantity value is reached. [0013] In various embodiments, the key contains data including any one of or a combination of product serial number, jurisdictional data, shelf-life or quantity data. [0014] In another aspect, the invention provides a system for authenticating a bulk quantity of a consumable product with a corresponding product that utilizes the consumable product comprising: a key and reader for operative connection to the corresponding product, the key containing information relating to a consumption parameter of the consumable product and the reader having a controller for monitoring the consumption parameter of the consumable product within the corresponding product as the consumable product is being consumed relative a to quantity value; the controller monitoring consumption of the consumable product within the corresponding product and determining when the quantity value is reached, the controller providing an event output when the quantity value is reached to an output event circuit operatively connected to the controller. [0015] In further embodiments, the output event circuit includes an audio and/or visual circuit for providing an audio or visual signal to an end-user. [0016] In other embodiments, the quantity value is any one of or a combination of total volume, total mass or time. [0017] In other embodiments, the controller includes means for altering the operation of the corresponding product when the quantity value is reached which may include increasing the amount of material being dispensed when the quantity value is reached, decreasing the amount of material being dispensed when the quantity value is reached or stopping the amount of material being dispensed when the quantity value is reached. The key may also contain data including any one of or a combination of product serial number, jurisdictional data, shelf-life or quantity data. [0018] In yet another aspect, the invention provides a retro-fit system for detecting consumption of a consumable product with a corresponding product that utilizes the consumable product, the system for retro-fit connection to the corresponding product, the system comprising: a body for attachment to the corresponding product, the body operatively containing: a controller operatively connected to a power supply; a reader operatively connected to the controller, the reader for operative connection with a key containing quantity information relating to the consumable product; a use detector operatively connected to the controller for detecting operation events of the corresponding product; wherein the controller includes a counter for counting operation events and includes means for calculating total consumption and comparing total consumption to the quantity information, the controller having means to activate an alarm system operatively connected to the controller in the event that total consumption exceeds the quantity information. [0019] In one embodiment, the system includes a solar cell operatively connected to the controller and power supply for providing solar energy to the power supply. [0020] In further embodiments, the system may also include a communication interface operatively connected to the controller for communicating any one of or a combination of total consumption information or alarm events to a computer network. [0021] In another embodiment, the system includes a communication interface operatively connected to the controller for communicating any one of or a combination of total consumption information or alarm events to an adjacent retrofit system. [0022] In another aspect, the invention includes two or more retro-fit systems, each for detecting consumption of a consumable product with a corresponding product and each operatively connected to separate corresponding products and wherein each retro-fit system includes means for communicating consumption data between each retro-fit system. In these embodiments, each controller may calculate total consumption based on consumption information received from each retro-fit system for determining if an alarm condition exists. Key information between each controller can also be exchanged to provide authorization to multiple retro-fit systems within a network. BRIEF DESCRIPTION OF THE DRAWINGS [0023] The invention is described with reference to the accompanying figures in which: [0024] FIG. 1 is a schematic diagram of a key and reader system on a corresponding product (eg. dispenser) and a corresponding bulk product in accordance with one embodiment of the invention; [0025] FIG. 2 is a schematic diagram of a retro-fit kit for use with a corresponding product (eg. a dispenser) in accordance with one embodiment of the invention; and, [0026] FIG. 3 is a flow chart illustrating typical logic utilized in monitoring the consumption of a consumable product in accordance with one embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION [0027] With reference to the figures, various embodiments of systems and methods for authorizing bulk products with specific dispensing apparatus are described. In addition, systems and methods of retro-fitting authorization technology to existing equipment are described. [0028] In the context of this invention, bulk or consumable products generally mean products that may be any one of or a number of difficult to mark, relatively inexpensive and/or that are normally shipped in larger containers with a number of smaller packages/containers within the bulk shipment. These products are generally used with a corresponding product that will either dispense or use the consumable product and which collectively constitute a product pair. Examples of such product pairs include but are not limited to food product dispensers (eg. breakfast cereal, condiment and milk dispensers), bulk chemical dispensers (eg. soap, window cleaner, surface sanitizer dispensers), and product dispensers (eg. hot drink stir stick dispensers). [0029] As shown in FIG. 1 , generally the invention provides a key 12 that is associated with a bulk product or container 22 and that is coded to contain information about a consumable product 14 that may be within a smaller package within a bulk container 22 . The key is interfaced with a reader 16 within a dispensing apparatus 18 that can read and obtain data from the key. The key contains information about the consumable product such that the dispensing apparatus 18 (dispenser) will operate in an unrestricted mode only if the key is interfaced (eg. within a slot or opening 20 ) with the dispenser and is otherwise being operated consistently within the authorized parameters of the consumable product. [0030] For example, a restaurant operator may provide a breakfast cereal dispenser 18 into which fixed volumes/weights of bagged breakfast cereal are inserted. An end user typically uses the dispenser by approaching the dispenser and turning a knob in order to dispense a fixed volume of breakfast cereal. During normal operation, restaurant staff will periodically monitor the level of breakfast cereal in the dispenser and when the levels become low, re-fill the cereal dispenser with a pre-packaged volume of breakfast cereal from a store room. [0031] As shown in FIG. 1 , the cereal for each re-fill may be contained in a plastic bag that was purchased as a bulk shipment 22 of breakfast cereal. For the purposes of illustration, the bulk shipment may contain 10 bags of breakfast cereal (numbered 1 to 10). In this case, after retrieving a bag of breakfast cereal from the bulk shipment box, the restaurant staff will simply open a new bag of cereal and pour it into the dispenser. As can be appreciated, as the plastic bag is thrown away immediately after emptying, marking the individual plastic bag with specific coded information will be of little use for the purposes of keying as the bag itself is not interfaced with the cereal dispenser. Moreover, busy restaurant staff cannot be concerned with ensuring that proper keying is occurring every time they fill up a breakfast cereal dispenser. [0032] However, and in accordance with the invention, replacing a key in the dispenser each time a new bulk shipment box is opened can provide an effective system for ensuring that the authorized breakfast cereal is used in the dispenser and involvement with end-users is minimal. In our example, the bulk shipment box 22 is provided with a key 12 that can be interfaced with the dispenser 18 and contain information that permits operation of the dispenser for a specific period of time and/or to dispense a specific quantity of product. Upon the expiry of the specific parameters of the key (primarily a maximum quantity), the dispenser will prevent operation of the dispenser and/or signal that new product is required. For example, the key may be coded to permit the equivalent of 10 bags of cereal to be dispensed from the dispenser. Thus, after the assumed volume/weight of 10 bags of cereal (with appropriate allowances), the dispenser may be shut-down. If the dispenser is shut-down, this will provide a clear signal to the end-user (i.e. restaurant staff) that a new key must be interfaced with the dispenser. [0033] Alternatively, the dispenser may simply signal through a signal system 24 that the key has expired by a visual 24 a and/or audio 24 b signal that will continue until a new key is inserted. In this case, the dispenser may not be shut-down upon the expiry of the key where, in this embodiment it would be assumed that the warning signal is sufficient reminder to the end-users that an authorized product key must be interfaced with the dispenser to ensure that authorized product is used with the dispenser. [0034] While a system only incorporating a signal system that does not completely shut-down a dispenser will not absolutely prevent the use of unauthorized product in the dispenser, as a user could add cereal to the dispenser that has been obtained from a non-authorized manufacturer, at the very least the warning system will substantially reduce the use of unauthorized products as the warning system may be sufficiently disruptive to the operation of the dispenser that it will motivate the end-user to obtain a new key. [0035] In various embodiments, the packaging of the bulk product may also be configured to ensure that opening the bulk product ensures that the first product out of the box is matched with a new key to ensure that the new key is paired with the dispenser when the first product is used. In our example, the key 12 is attached to bag 1 and would be clearly marked to ensure it is the first product to be used. In one embodiment, each product is marked with a number to advise users the order in which the product should be utilized. In one embodiment, after consumption of a certain percentage of the bulk product, a visual reminder 8 a (eg. a card) may also be provided to remind a user to order new bulk product although this can also be achieved electronically through the system as described below. [0036] As can be understood, the above technology can be applied to a wide array of dispenser/product pairs such as laundry machines/soap, dishwashers/soap, paper dispensers/paper, hand sanitizers/sanitizer, waxing machines/wax, milk dispensers/milk as well as many other products. [0037] In various embodiments, the key can be configured with a variety of data. As noted above, this can be an authorized weight/volume of product and/or a time parameter. Time-based authorizations can be utilized to ensure that shelf life/expiry dates are respected. That is, in the case of a product such as a milk dispenser/milk container product pair, the milk dispenser may monitor both the weight/volume of milk being dispensed as well as the shelf-life date. In this example, the bulk quantity of milk may have a code that indicates that 25 liters of milk can be dispensed as well as a code indicating that the shelf-life of the product is 7 days. Upon the expiry of either parameter, the dispenser may then enter an unauthorized condition where one or more alarms are presented to the user. [0038] In addition, authorization to ensure distribution control can also be implemented. As an example, a manufacturer may wish to prevent a distributor in one jurisdiction from selling into another jurisdiction. That is, a first distributor may be authorized by a manufacturer to sell product in a first jurisdiction but not be authorized to sell product into a second jurisdiction due to contractual obligations with a second distributor in a second jurisdiction. However, in the absence of authorization technology that does not individually mark each end-product, it is effectively impossible to enforce jurisdictional boundaries with each distributor. With the subject system, an appropriate jurisdictional code can be attached to each bulk shipment to ensure that a product can effectively only be paired to a corresponding product of the product pair in an authorized jurisdiction. [0039] Importantly, the subject system also allows the cost of authentication between product pairs to be reduced as many of the disadvantages of specific dispenser/product pairing can be obviated. For example, in many product pairs, there is substantial additional cost associated with incorporating authentication technology within the specific geometries of products. That is, in order to ensure that a dispenser using a specific refill cartridge can authenticate in a manner that is reliable and/or possible, significant geometric limitations of the physical dimensions of the products may have to be overcome in order to effectively provide product pair linking. [0040] In the subject system, the key system may be substantially simplified in terms of its geometric shape and/or size. For example, the key could be a simple, thin paper or plastic card that contains the authorization information. Similarly, the reader may be a simple slot that receives the key. Importantly, by simplifying the geometry between the key and reader in such a way that it is not actually on the product packaging or otherwise incorporated into the consumable product, allows the key and reader to be located in favorable locations on the dispenser. For example, the reader can likely be configured to a position of the dispenser where there is naturally dead volume within the dispenser and thus may be more readily incorporated into existing dispenser designs. [0041] Furthermore, the key and reader may also be established as a retro-fit kit for certain products, where an existing dispenser can be retrofit to include bulk authorization functionality. As shown in FIG. 2 , a retro-fit kit 50 may include a reader 16 for receiving a key 12 within a slot 20 and associated authorization electronics contained within a compact package. Typically, the package will include means to interrupt power 12 f to the dispenser and/or provide a visual or audio warning through an output system 24 a, 24 b to an end-user. While a specific retro-fit kit may be designed for a specific dispenser, based on the specific shape and available volumes within the dispenser, many different dispensers may be able to utilize the same kit to achieve the desired functionality given that many dispensers will have at least a minimum available volume for configuration of the kit. [0042] In one embodiment, the kit may be externally configured to the dispenser and only utilize a visual or audio warning system 24 a, 24 b that does not require wiring to the dispenser. For example, the retro-fit kit may be a box 40 that is permanently or semi-permanently attached to the exterior of the dispenser. In this case, a manufacturer with a line of dispensers may retroactively connect a retro-fit authentication system to the exterior of the dispenser by an appropriate attachment system such as screws, bolts, two-side adhesive tape and/or glue. The manner in which the authentication system is attached may be sufficiently secure that attempts to remove the retro-fit kit will result in damage to the dispenser, although this may not be required for certain installations. The box will contain an appropriate controller 16 a and reader 20 to interface with a key 12 as described above. [0043] In one embodiment, the retro-fit kit will include a rechargeable battery 12 b that is configured to a solar cell 12 c for charging the battery. In this embodiment, which will be particularly useful for dispensers that are deployed in lighted locations, the solar cell will ensure that the battery remains charged such that, the warning system will be able to provide its warning for a substantial period of time, for example, for at least several weeks, and potentially indefinitely in the event that the solar power cell has a sufficient power rating to provide continuous power. In this case, the controller 12 a may also be programmed to provide an alarm sequence that is balanced to the availability of power within the battery. In the case of an audio alarm, the alarm needs only to be sufficiently loud in order to be noticeable but not so loud as to be uncomfortable. While a visual alarm may also be implemented, on its own this may be less preferred. [0044] In those embodiments where the retro-fit kit is simply configured to the exterior of the dispenser and does not directly interface with the internal dispensing mechanisms of the dispenser, the detection of operation events such as rates of consumption can be implemented for certain types of dispensers. For example, for those dispensers that include a motor (or systems that produce identifiable physical effects) that is actuated each time a dispenser operation occurs, the retro-fit kit may include a vibration sensor 12 d (or similar device) that would detect the movement of the motor or related or similar components. Thus, the retro-fit kit could detect and monitor the number of dispense operations to calculate when an authorization key is no longer valid. As an example, in the case of a soap dispenser, the soap dispenser may include a motor and valve mechanism to dispense a fixed volume of soap with each actuation. In this case, after an authorization key has been inserted into the retro-fit kit box 40 , the retro-fit kit controller 16 a would simply count the number of dispenses by detecting motor vibration each time the motor is turned on. Thus, based on the knowledge of the volume per dispense, the number of valid dispenses can be calculated. After reaching the threshold number of dispenses, the alarm system 24 a, 24 b would be actuated. Other types of sensors may also be provided including strain gauges, optical and/or ultrasonic sensors. [0045] This system may also be used as a retro-fit notification system for advising personnel that a consumable product is nearing exhaustion and will need replacement. In this aspect of the invention, the retro-fit notification system may be implemented without the bulk authentication concepts described above and may simply be a means of advising when an individual quantity of a consumable product is nearing exhaustion. In this case, for example when 80% of the product has been consumed, the alarm system may actuate at a first level, perhaps flashing a small LED light at a 5 second interval. When 90% of the product has been consumed, the alarm system may flash the LED light at a 2 second interval. When 95% of the product has been consumed, the alarm system may add an audio alarm at a 10 second interval. Thus, when service personnel are in the proximity of the dispenser, they can make a determination of the level of product remaining in the dispenser. As understood by those skilled in the art, any number of alarm conditions may be designed and incorporated. [0046] In addition to motor vibration sensors, other means of detecting the number of actuations may be used. For example, the retro-fit kit may include an infra-red or ultrasonic sensor 12 e that detects the presence of an end-user and base the consumption calculation on the number of times an end-user is detected. [0047] The ability to retro-fit an authentication system to product pairs may be particularly beneficial within certain businesses or chains of business where factors such as product quality are essential components of a business. For example, in the case of franchises, it is often very important for franchisers to control the supply of product to their franchisees to ensure that customers receive product of consistent quality across multiple locations and over time. Very often, the good will of the franchise business will depend on the consistency of the product that is delivered to customers. While a franchise contract may require that product be purchased from authorized sources, it may be difficult to ensure that the actual product being sold was in fact purchased from an authorized source. [0048] For example, while a national chain of coffee shops may require that only coffee of a specific brand is used in the coffee brewing machines of the franchise, a franchisee may choose to utilize another (possibly less expensive) source of coffee in the coffee machine. However, if a retro-fit authorization kit is configured to a coffee machine, the retro-fit kit may be able to count the number of brew cycles the coffee machine goes through as a measurement of the consumption of coffee and thereafter activate the alarm system if an alarm condition is detected. [0049] In situations where multiple dispensing machines may be utilizing bulk product from a single bulk shipment (as shown in FIG. 1 ), different dispensers may have to share information to ensure that consumption rates are being properly monitored. Accordingly, a retro-fit circuit may also include wireless functionality in the form of a communication interface 12 g that collectively enables adjacent machines to monitor the total consumption rates across more than one machine. In addition, if consumable product is being received from a single bulk packaging source, the controller in each adjacent retro-fit unit may share key information across a network such that only a single key is required to provide authorization to multiple retro-fit units. [0050] Wireless technology may also be utilized as a reminder to users when to initiate the re-ordering of product. For example, a coffee machine that has calculated that 50 pots of coffee have been brewed since the authentication key was interfaced with the coffee machine, may initiate a network event that triggers an email, SMS, or similar alert being sent to an owner to order additional coffee. Communicative technology, including both wireless and wired technology, may also be utilized to inform of non-compliance events. For example, if a franchisee is utilizing a non-authorized coffee bean, an alert can be generated by a communication interface 12 g and sent to the franchiser to inform of the non-compliance event. [0051] In various embodiments, the keying system will also only be accessible to higher level users (eg. restaurant staff) as opposed to final end-users (eg. customers). For example, in our bulk cereal example, restaurant staff (higher level user) may have access to the authentication key 12 only when a dispenser cabinet is opened with a regular lock key so as to minimize the risk of tampering by the end-user (restaurant customer). [0052] For the retro-fit kit embodiment, similarly a lock or cover 30 may be provided that requires a regular lock key to open in order to prevent end-user access to the key 12 . Authentication [0053] Authentication can occur using a variety of authentication methodologies and systems including the authentication systems as described in U.S. Pat. No. 7,793,839 and co-pending application PCT/CA2011/001008 incorporated herein by reference. Other authentication systems could include bar codes, magnetic stripe, smart cards etc. Codes will typically include serial numbers and product specific codes that represent authorized weights/volumes/times etc. Importantly, the key and reader combinations may utilize read-only or read/write technologies depending on the specific product pair and requirements of the manufacturers/distributors and/or end users. in the read/write scenario, after the expiry of the product specific code (i.e. the weight/volume/time code), the code on the key may be irreversibly altered to prevent future reading of the code by any reader. [0054] FIG. 3 is a flow chart depicting a typical process by which electronics in the corresponding product (eg. a dispenser) would monitor consumption of a consumable product. While an authorization key is not present 501 the system would be in an unauthorized mode and operation of the dispenser would be in a corresponding condition (eg. Increasing, decreasing the dispensed quantity of product and/or preventing operation and/or providing a visual/audio signal). If the authorization key is present 502 , data from the key would be read 503 and determined if the product was authorized with the dispenser 504 . If the product was authorized, a dispense counter would be set to a value N 505 and would decrease the counter by one with each use 506 . The dispenser would continue to operate while the counter was greater than zero 507 . For any condition that was interpreted as unauthorized, the system would return to idle 501 . [0055] Although the present invention has been described and illustrated with respect to preferred embodiments and preferred uses thereof, it is not to be so limited since modifications and changes can be made therein which are within the full, intended scope of the invention as understood by those skilled in the art.

This application generally relates to systems and methods for authenticating a bulk quantity of a consumable product with a corresponding product. More specifically, the invention associates a bulk quantity of the consumable product with a product parameter such as a consumption rate of the consumable product within the corresponding product; provides and authorizes a key and/or reader with the bulk quantity and consumption rate data to a specific corresponding product wherein the bulk quantity and consumption rate data are correlated to a maximum consumption quantity value; monitoring consumption of the consumable product within the corresponding product until the maximum consumption quantity value is reached; and providing an event output to the corresponding product when the maximum consumption quantity value is realized.

FIELD OF THE INVENTION [0001] The present invention involves a wound dressing comprising chemically modified chitosan fiber or unmodified chitosan fiber, and chemically modified cellulose fiber, providing clinical benefits in bacteriostatic and fluid absorption. The wound dressing is useful in treatment of chronic wounds, such as venous stasis ulcers, pressure ulcers, diabetic foot ulcers and other chronic ulcers. BACKGROUND OF THE INVENTION [0002] It is well known that nurses are facing some challenges when selecting the right wound dressing for the management of chronic wounds. In addition to managing the wound exudates, they also need to consider providing a good healing environment for the wound. This good healing environment includes inhibiting the growth of microorganisms. [0003] Chitosan has a bacteriostatic property by the existence of the amino groups in the molecule of chitosan. The positive charge of a chitosan molecule neutralizes the negative charge of cell membrane of bacteria inhibiting the growth of the bacteria. On the other hand, small molecules of chitosan penetrate through the bacterial cell membrane into the cell nucleus to inhibit enzyme formation. This can be observed in the general inhibition test. When the chitosan wound dressing is placed onto a Petri-dish for 24 hrs that has been covered with bacteria, a clear or less cloudy can be seen underneath the wound dressing whilst all other areas of the bottom of the Petri-dish displayed a cloudy appearance. This means that the area underneath the chitosan wound dressing has less bacterial growth than other areas which has not been covered by the chitosan dressing. This demonstrates that chitosan has a bacteriostatic property, which can be used to treat infected wounds. [0004] Generally speaking, silver wound dressings also have bacteriostatic properties. However, a wound dressing containing silver which may be cytotoxic. [0005] EP0690344 and U.S. Pat. No. 3,589,364 disclose an absorptive wound dressing manufactured by carboxymethyl cellulose fibers. WO2010/061225 discloses a method of preparing modified cellulose fiber by forming a water insoluble alkyl sulfonate cellulose fiber to improve its absorbency. According to the above patents, high absorbency can be obtained when the cellulose fibers are chemically modified. However this type of dressing does not have bacteriostatic properties. [0006] Alginate dressings are also used in the management of chronic wounds. However alginates do not have bacteriostatic properties, its absorbency is also lower than that of chemically modified cellulose fibers. [0007] EP0740554 and U.S. Pat. No. 6,471,982 disclose a fibrous wound dressing prepared by blending a gelling fiber such as an alginate fiber and a non-gelling fiber such as cellulose fiber. This blending method may reduce the cost of the product. [0008] U.S. Pat. No. 7,385,101 discloses a wound dressing composed of a silver nylon fiber and an absorptive fiber. This dressing is used in managing the infected wounds. [0009] U.S. Pat. No. 5,836,970 describes a wound dressing composed of chitosan fiber and alginate fiber. This patent disclosed the bacteriostatic and haemostatic properties of chitosan fiber and the absorbency of alginate fiber. [0010] U.S. Pat. No. 6,458,460, EP0927013 and CN1303355 describe a wound dressing containing two gelling fibers, one is carboxymethyl cellulose fiber and the other one is alginate fiber. The mixture of these two fibers helps to improve the dressing absorbency, but does not have bacteriostatic property. [0011] EP1318842 disclosed a wound dressing composing a silver fiber and a non-silver fiber. This wound dressing possesses antibacterial function as well as absorbency. This type of dressing generally is cytotoxic. [0012] CN1313416 disclosed a method of blending cotton fibers and chitosan fibers. Although the purpose of this invention was not for wound care, it also disclosed that the product prepared by this method has antibacterial function. [0013] Therefore it become a clinical need to develop a wound dressing that is very absorbent to wound fluid but can also provide some bacteriostatic functions. SUMMARY OF THE INVENTION [0014] The present invention involves a wound dressing characterized in that the wound dressing comprises of chitosan fibers and chemically modified cellulose fibers. The chitosan fiber can be chemically modified or unmodified fiber. Particularly, the invention involves a wound dressing prepared by blending chitosan fibers and chemically modified cellulose fibers to obtain a fabric. Because of bacteriostatic property of the chitosan fiber and the high absorption capacity of the chemically modified cellulose, the dressing of the present invention can provide an ideal healing environment of bacteriostatic properties and fluid absorption to the chronic wound. Furthermore, the ratio of the chitosan fiber to chemically modified cellulose can be adjusted to suit the need of each type of the wound. For example for a wound that has a large amount of fluid but has not yet developed the wound infection, a dressing containing a small percentage of chitosan fiber is more suitable, as the small amount of chitosan fiber may be sufficient to prevent the wound from infection whilst the majority of the dressing is made of chemically modified cellulose which can provide the fluid absorption capacity needed for this type of the wound exudate. For example 30% of chitosan fiber and 70% of chemically modified cellulose fiber. However for the wound type that has already got infection, the dressing with more chitosan fiber is best suited, such as 70% of chitosan fiber and 30% of chemically modified cellulose fiber. [0015] The present invention also relates to the application of the said wound dressing in the management of chronic wounds [0016] Particularly, the invention involves a wound dressing wherein the wound dressing is composed of 5-95% w/w of chitosan fibers, 95-5% w/w chemically modified cellulose fibers, preferably 10-90% w/w of chitosan fibers, 90-10% w/w chemically modified cellulose fibers. All fiber percentage is based on the total weight of chitosan fiber and the chemically modified cellulose fibers. The wound dressing in the present invention is manufactured by blending of 5-95% w/w of chitosan fibers and 95-5% w/w chemically modified cellulose fibers. The blending is achieved during the carding and nonwoven process, i.e. the two fibers are weighed separately and blended together during or before the fiber opening stage, then carded together to form a nonwoven fabric made of a homogeneous mix of two fibers. [0017] This invention also involves a method of manufacturing the said wound dressing by blending of chemically modified or unmodified chitosan fibers and chemically modified cellulose fibers through a nonwoven process, followed by slitting, cutting, packaging and sterilisation. [0018] The wound dressing in the present invention can be used in the management of chronic wounds, such as venous stasis ulcers, pressure ulcers, diabetic foot ulcers and other chronic ulcers. BRIEF DESCRIPTION OF THE DRAWINGS [0019] FIG. 1 shows the photo of the area underneath of the dressing prepared by blending 5% of chitosan fiber and 95% of chemically modified cellulose fiber at 1 day against Staphylococcus aureus; [0020] FIG. 2 shows the photo of the area underneath of the dressing prepared by blending 95% of acylated chitosan fiber and 5% of chemically modified cellulose fiber at 1 day against Escherichia coli; [0021] FIG. 3 shows the photo of the area underneath of the dressing prepared by blending 50% of acylated chitosan fiber and 50% of chemically modified cellulose fiber at 1 day against Staphylococcus aureus; and [0022] FIG. 4 shows the device that was used in the wet strength tensile testing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0023] In an example of the present invention, chitosan fibers and chemically modified cellulose fibers were prepared respectively by their manufacturing process. Chitosan fiber can be prepared by first dissolving the chitosan powder in an acetic acid aqueous solution, then extruding the mixed chitosan solution (dope) into sodium hydroxide solution for precipitation. This is followed by washing, stretching, drying, cutting into staple fiber. The degree of deacetylation of the chitosan fiber is 50% or above, preferably 70% or above. Chemically modified chitosan fiber is prepared by reacting the chitosan fiber with certain chemicals so that the chitosan fiber becomes more absorbent or gelling. Typical examples of this kind of treatment are carboxymethylation or acylation treatments. [0024] The chemically modified chitosan fiber used in the present invention is acylated chitosan fiber or carboxymethyl chitosan fiber. Carboxymethyl chitosan fiber is prepared by reacting the chitosan fiber with halogenated acetic acid. The acylated chitosan fiber is obtained by reacting the chitosan fiber with succinic anhydride. These chemical treatments make the chitosan fiber absorbent and gelling. [0025] The chemically modified cellulose fiber used in the present invention is carboxymethyl cellulose fiber, preferably the carboxymethylated solvent spun cellulose fiber. Or the chemically modified cellulose fiber used in the present invention is a water insoluble cellulose alkyl sulfonate fiber. The chemically modified cellulose fiber is prepared by reacting standard cellulose fiber or solvent spun cellulose fiber (Lyocell) with certain chemicals for increased absorption capacity or gelling property. The preferred chemically modified cellulose fiber is carboxymethyl cellulose fiber or water insoluble cellulose alkyl sulfonate fiber. [0026] The unmodified chitosan fiber has generally an absorbency to Solution A (a solution containing 8.298 g sodium chloride and 0.368 g calcium chloride dihydrate per liter) of 100% or 200%. The chemically modified chitosan fiber or cellulose fiber has an absorbency to Solution A (a solution containing 8.298 g sodium chloride and 0.368 g calcium chloride dihydrate per liter) of 500% or above, sometimes can be as high as 3000%. [0027] It is well known that the strength of a wound dressing or a nonwoven material is different in the machine direction compared to the cross machine direction. The machine direction (MD) is the direction that materials move during the manufacturing. The cross machine direction (CD) is the direction 90 degree to the MD. Normally the strength of a nonwoven material in machine direction is lower than that in cross machine direction. Although it is difficult to distinguish machine direction and cross machine direction when the material is cut into square or rectangle dressing, the direction with lower strength can be considered as the MD. Therefore a wound dressing generally has two strengths, one is MD strength and the other is CD strength. The average strength (including average wet strength) is the average of MD and CD strengths. The average wet strength of the wound dressing in the present invention is 0.3 N/cm or above, preferably 0.5 N/cm, more preferably 1.0 N/cm, most preferably 1.8 N/cm or as high as 6.0 N/cm. [0028] In an example of the present invention, chitosan fibers and chemically modified cellulose fibers are blended before or during the carding process. Usually, the blending process takes place in the fiber opening stage, followed by carding and needling processes. The carding process can further open and blend the two fibers to achieve a homogeneous mix. The typical nonwoven method is needle punching process. [0029] In another example of the present invention, the chitosan fibers and the chemically modified cellulose fibers may contain surfactant, lubricant or antimicrobial agent. Some of these are process aids, others are for special purposes. For example, to apply Tween 20 onto the fiber surface can improve the process efficiency of the carding and the nonwoven process. For the purpose of enhancing the dressing's ability to kill bacteria and fungi, it will be necessary to add some antimicrobial agents to the fiber such as silver or PHMB. [0030] In an example of the present invention, the content of chitosan fibers and the chemically modified cellulose fibers can be varied to suit the functional requirement of the wound dressing. The ratio of chitosan fiber can be between 5-95% w/w, calculated on the total weight of both fibers. The ratio of chemically modified cellulose fiber can be 95-5% w/w, calculated on the total weight of both fibers. [0031] Preferably, the present invention involves a wound dressing composed of 10-90% w/w of chitosan fiber and 90-10% w/w of chemically modified cellulose fiber. [0032] In the present invention, the fiber's linear density and length are controlled to suit the wound dressing manufacturing process. The linear density of the chitosan fibers and the chemically modified cellulose fibers is between 0.5 dtex to 5 dtex, preferably 2 dtex to 4 dtex. The length of the chitosan fibers and the chemically modified cellulose fibers is between 10 mm to 125 mm. [0033] The present invention also involves a method of preparing the said wound dressing. The method comprises blending the chitosan fibers and the chemically modified cellulose fibers together during or before the fiber opening stage, then converting the blended fibers into a fabric through a nonwoven process, then cutting, packing and sterilizing. Preferably, the nonwoven process is needle punch process. Other nonwoven process can also be used. For example, one of the said fibers can be converted into a fabric first, and then the other fiber is laminated onto this pre-made fabric by needling or chemical bonding. Although the dressing manufactured by this method is not a homogeneous blend of the two fibers (chitosan fiber and chemically modified cellulose fiber), the dressing can still provide a bacteriostatic environment and high absorbency functions. Another method is to prepare a fabric that contains 100% chitosan fiber (either chemically modified or unmodified, or both) and a fabric that contains 100% chemically modified cellulose fiber first, and then laminate the two fabrics together by needling or chemical bonding. [0034] According to the shape of different wounds, the wound dressing composed of chitosan fibers and chemically modified cellulose fibers can be cut into a square or rectangular shape to satisfy various applications in wound care. [0035] The wound dressing in present invention is usually be packed by a known packaging material such as paper/poly, paper/paper, or foil/foil, and then sterilized by gamma irradiation or ETO. [0036] The present invention can be further illustrated by the following examples. EXAMPLE 1 [0037] Raw material: Chitosan fiber: linear density 2.0 dtex, fiber length 50 mm. The fiber contains 1% by weight of surfactant (Tween 20). The fiber's absorbency to the solution containing 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dehydrate (solution A) is over 110%. Chemically modified cellulose fiber: linear density 1.4 dtex, fiber length 38 mm. The fiber is modified by carboxymethylation reaction. The fiber's absorbency of a solution containing 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dehydrate (solution A) is 2200%. [0038] 100 g of chitosan fiber and 900 g of chemically modified cellulose fiber are blended and opened manually for 5 mins, then fed into a single cylinder card (Cuarnicard). The fibers are further blended into the hopper and the card, then opened and formed into a web. The web is crosslapped and needled into a nonwoven with a base weight of 130 gsm. [0039] Cut the fabric into 10×10 cm, pack the dressing into pouches then sterilise the dressing by gamma irradiation. [0040] The dressing has an absorbency of 18.5 g/g, a wet strength in CD direction of 0.45 N/cm, in MD direction of 0.17 N/cm, average 0.3 N/cm. EXAMPLE 2 [0041] In order to observe the bacteriostatic performance of the wound dressing in Example 1, approximately 0.25 mL of Staphylococcus aureus at a concentration of 10E6-10E7 cfu/mL was evenly coated on a Petri dish. Then the dressing obtained from Example 1 was cut into 2×2 cm and placed into the Petri dish. The Petri dish was then cultured at temperature of 37° C., and observed for the growth of bacteria on the plate. FIG. 1 shows the area underneath the dressing at 1 days. [0042] From FIG. 1 , it can be seen that the area underneath of the dressing is less cloudy than the rest of the Petri dish, indicating less growth of bacteria underneath of the dressing. EXAMPLE 3 [0043] Raw material: Acylated Chitosan fiber: linear density 2.0 dtex, fiber length 50 mm. The fiber contains 1% by weight of surfactant (Tween 20). The fiber's absorbency to the solution containing 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dehydrate (solution A) is over 1500%. Chemically modified cellulose fiber: linear density 1.7 dtex, fiber length 50 mm. The fiber is modified by carboxymethylation reaction. The fiber's absorbency of the solution containing 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dehydrate (solution A) is 1500%. [0044] Take 400 g of chitosan fiber and submerse the fiber in ethanol solution for 30 minutes. Squeeze the fiber to dry then place the fiber into a 0.1 g/m 1 succinic anhydride solution (894 g of succinic anhydride in 8940 ml of ethanol). Heat to 70° C. for 40 mins. Squeeze the fiber to dry then wash the fiber in an ethanol solution, followed by submersing the fiber in an ethanol solution containing Tween 20. The final steps are drying the fiber to an acceptable moisture content and cutting the fiber to a staple length. [0045] Take 190 g of the above acylated chitosan and 10 g of chemically modified cellulose fiber, blend and open two fibers manually for 5 mins, then fed the blend into a single cylinder card (Cuarnicard). The fibers are further blended into the hopper and the card, then opened and formed into a web. The web is crosslapped and needled punched into a nonwoven with a base weight of 130 gsm. [0046] Cut the fabric into 10×10 cm, pack the dressing into pouches then sterilise the dressing by EtO. [0047] The dressing has an absorbency of 14.6 g/g, a wet strength in CD direction of 2.5 N/cm, in MD direction of 1.1 N/cm, average 1.8 N/cm. EXAMPLE 4 [0048] In order to observe the bacteriostatic performance of the wound dressing in Example 3, approximately 0.25 mL of E. Coli at a concentration of 10E6-10E7 cfu/mL was evenly coated on a Petri dish. Then the dressing obtained from Example 3 was cut into 2×2 cm and placed into the Petri dish. The Petri dish was then cultured at temperature of 37° C., and observed for the growth of bacteria on the plate. FIG. 2 shows the area underneath the dressing at 1 days. [0049] From the FIG. 2 , it can be seen that the area underneath of the dressing is less cloudy than the rest of the Petri dish, indicating less growth of bacteria underneath of the dressing. EXAMPLE 5 [0050] Raw material: Acylated Chitosan fiber: linear density 2.2 dtex, fiber length 75 mm. The fiber's absorbency of the solution containing 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dehydrate (solution A) is over 1500%. Chemically modified cellulose fiber: linear density 1.7 dtex, fiber length 50 mm. The fiber is modified by carboxymethylation reaction. The fiber's absorbency of the solution containing 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dehydrate (solution A) is 1500%. [0051] Take 1000 g of the acylated chitosan and 1000 g of carboxymethyl cellulose fiber, blend and open two fibers manually for 5 mins, then fed the blend into a single cylinder card (Cuarnicard). The fibers are further blended into the hopper and the card, then opened and formed into a web. The web is crosslapped and needled punched into a nonwoven with a base weight of 110 gsm. [0052] Cut the fabric into 10×10 cm, pack the dressing into pouches then sterilise the dressing by EtO. [0053] The dressing has an absorbency of 14.6 g/g, a wet strength in CD direction of 1.5 N/cm, in MD direction of 0.5 N/cm, average 1.0 N/cm. EXAMPLE 6 [0054] In order to observe the bacteriostatic performance of the wound dressing in Example 5, approximately 0.25 mL of Staphylococcus aureus at a concentration of 10E6-10E7 cfu/mL was evenly coated on a Petri dish. Then the dressing obtained from Example 5 was cut into 2×2 cm and placed into the Petri dish. The Petri dish was then cultured at temperature of 37° C., and observed for the growth of bacteria on the plate. FIG. 3 shows the area underneath the dressing at 1 days. [0055] From the FIG. 3 , it can be seen that the area underneath of the dressing is less cloudy than the rest of the Petri dish, indicating less growth of bacteria underneath of the dressing. EXAMPLE 7 [0056] Raw material: Acylated Chitosan fiber: linear density 2.2 dtex, fiber length 75 mm. The fiber's absorbency of the solution containing 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dehydrate (solution A) is over 800%. Chemically modified solvent spun cellulose fiber: linear density 1.4 dtex, fiber length 60 mm. The fiber is modified by carboxymethylation reaction. The fiber's absorbency of the solution containing 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dehydrate (solution A) is 3000%. [0057] Take 1000 g of the acylated chitosan and 1000 g of carboxymethyl cellulose fiber, blend and open two fibers manually for 5 mins, then fed the blend into a single cylinder card (Cuarnicard). The fibers are further blended into the hopper and the card, then opened and formed into a web. The web is crosslapped and needled punched into a nonwoven with a base weight of 160 gsm. [0058] Cut the fabric into 10×10 cm, pack the dressing into pouches then sterilise the dressing by EtO. [0059] The dressing has an absorbency of 17.5 g/g, a wet strength in CD direction of 0.9 N/cm, in MD direction of 0.2 N/cm, average 0.55 N/cm. EXAMPLE 8 [0060] Raw material: Acylated Chitosan fiber: linear density 2.2 dtex, fiber length 50 mm. The fiber's absorbency of the solution containing 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dehydrate (solution A) is over 800%. The fiber contains 1% of Tween 20. Carboxymethyl cellulose fiber: linear density 2.2 dtex, fiber length 50 mm. The fiber's surface was sprayed with about 3000 ppm PHMB as an antimicrobial fiber. [0061] Take 400 g of the acylated chitosan and 100 g of above antimicrobial carboxymethyl cellulose fiber, blend and open two fibers manually for 5 mins, then fed the blend into a single cylinder card (Cuarnicard). The fibers are further blended into the hopper and the card, then opened and formed into a web. The web is crosslapped and needled punched into a nonwoven with a base weight of 100 gsm. [0062] Cut the fabric into 10×10 cm, pack the dressing into pouches then sterilise the dressing by EtO. [0063] The dressing has an absorbency of 12 g/g, a wet strength in CD direction of 0.8 N/cm, in MD direction of 0.3 N/cm, average 0.55 N/cm. EXAMPLE 9 [0064] Raw material: Chitosan fiber: linear density 2.0 dtex, fiber length 50 mm. The fiber contains 1% by weight of surfactant (Tween 20). The fiber's absorbency to the solution containing 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dehydrate (solution A) is over 110%. Acylated chitosan fiber: fiber linear density 2.2 dtex, fiber length 50 mm. fiber's absorbency of a solution containing 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dehydrate (solution A) is 800%. The fiber contains 1% weight of Tween 20. [0065] 1900 g of chitosan fiber and 100 g of acylated chitosan fiber are blended and opened manually for 5 mins, then fed into a single cylinder card (Cuarnicard). The fibers are further blended into the hopper and the card, then opened and formed into a web. The web is crosslapped and needled into a nonwoven with a base weight of 180 gsm. [0066] Cut the fabric into 10×10 cm, pack the dressing into pouches then sterilise the dressing by EtO. [0067] The dressing has an absorbency of 7.2 g/g, a wet strength in CD direction of 6.9 N/cm, in MD direction of 4.8 N/cm, average 5.2 N/cm. [0068] Wet Strength Test Method [0069] The absorbency test for all samples of chitosan fiber, chemically modified cellulose fiber and all dressings followed the ISO standard ISO 13726-1: 2002 Part 1 Aspects of Absorbency. [0070] The ISO standard described a Solution A as the test solution. The solution A is made up with 8.298 g/l of sodium chloride and 0.368 g/l of calcium chloride dihydrate and distilled water. [0071] In order to get an accurate reading for the dressing's wet strength, particular when comparing samples manufactured at various conditions, the test for the dressing's wet strength was performed in the following method: [0072] 1) Cut a 2 cm strip off a test specimen, the strip length shall be at least 7 cm. With a 10×10 cm wound dressing, it is preferably to cut the second sample at a 90 degree angle to the first sample, so that samples of both MD and CD directions can be obtained at the same time, as shown in FIG. 4 . [0073] 2) Fold the sample in half, and place the sample into the test solution 3 which is contained in the container 2 . The test solution is Solution A as above. The height of the solution in the container shall be 2+/−0.5 cm. [0074] 3) Make sure that the sample's folded end is placed at the bottom of the device. Leave the sample in the device for 30 seconds. [0075] 4) Lift the sample out of the container, place the two ends of the sample which are still dry into the top and bottom clamps of the Tensile Tester. This will avoid the sample slippage during the tensile testing. [0076] 5) The distance between two jaws is 50 mm and the travel speed of the top jaw is set at 100 mm/min. [0077] 6) Record the maximum force (N) required to break the sample. It is recommended to test both strips of the same dressing (10×10 cm) at the same time period so that one with higher strength can be recorded as the CD, and the other as the MD. [0078] The average wet strength is the average of CD and MD value.

A wound dressing with bacteriostatic and hygroscopicity, preparation method therefore, and the use thereof in preparing a product for treating chronic wounds. The dressing comprises chitosan fiber and modified cellulose fiber.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling contact device such as a cam follower, used in the technical field of machine tool or the like, and more particularly to a rolling contact device which comprises a shaft having an outer track surface, an outer ring surrounding the shaft and having an inner track surfaces, and rolling elements disposed between the shaft and the outer ring in a relationship spaced apart from each other circumferentially of the shaft. 2. Description of the Prior Arts Heretofore, there is known a rolling contact device of the above mentioned type, in which one end of the shaft is adapted to be secured to an element of a machine and the peripheral surface of the outer ring is made in rolling contact with a cam surface of a cam serving as a cam follower. Such a cam follower is disclosed, for example, in Japanese Patent Publication No. 54-20534. The rolling contact device of this type is also used for moving a machine element together with the rolling contact device along a guiding rail with one end of the shaft secured to the machine element and with the peripheral surface of the outer ring in rolling contact with the rail. The above-mentioned rolling contact device of the prior art suffers from a problem that when a radial load exceeding a certain value, such as an impact load, is applied to the outer ring, permanent deformations or press traces occur on the contact portions of the track surface of the shaft, the rolling elements and the track surface of the outer ring, thereby deteriorating the precision of the device. SUMMARY OF THE INVENTION It is an object of the present invention to provide a rolling contact device which may solve the abovedescribed problem of the prior art. According to the present invention, a rolling contact device comprises: a shaft having an outer track surface; an outer ring surrounding the shaft and having an inner track surface; rolling elements disposed between the shaft and the outer ring in a relationship spaced apart from each other circumferentially of the shaft, the outer peripheral surface of the outer ring being adapted to be in rolling contact with a track surface of an element of an apparatus; and an at least one abutting portion provided on each of the shaft and the outer ring; the abutting portions on the shaft and the outer ring being radially opposed to each other with a small gap defined therebetween, such that, when a radial load exceeding a predetermined value acts on the outer ring, the abutting portions may abut against each other, thereby reducing radial load acting on contact portions of the track surface of the outer ring, the rolling elements and the track surface of the shaft. The above and other objects, features and advantages of the invention will become more apparent from the following description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a rolling contact device according to a first embodiment of the present invention. FIG. 2 shows the function and the advantage of a rolling contact device of the present invention. FIGS. 3, 4, 5, 6 and 7 show second, third, fourth, fifth and sixth embodiments of the present invention, respectively. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 shows a rolling contact device according to the first embodiment of the present invention. The rolling contact device comprises a shaft 1 having an outer track surface la, an outer ring 2 surrounding the shaft 1 and having an inner track surface 2a, and rolling elements 3 arranged between the shaft 1 and the outer ring 2 in rolling contact with the track surface laof the shaft 1 and the track surface 2aof the outer ring 2. The rolling elements are composed of needle rollers arranged in a relationship spaced apart from each other circumferentially of the shaft 1. The shaft 1 is integrally formed with a flange 1bat its left end for preventing outer ring 2 from moving to the left and slipping out from the shaft 1. The shaft 1 is formed with abutting portions 1c, 1dadjacent to the both ends of the track surface on each other, thereby relieving or reducing the load 1a, and the outer ring 2 includes abutting portions 1c, on each other, thereby relieving or reducing the load 1dlocated opposite to the abutting portions 1c, 1d, respectively. The abutting portions 1c, 1dand the abutting portions 2b, 2care opposite to each other with a gap G of a predetermined size or depth formed therebetween. When a radial load F, greater than a predetermined value, acts on the outer ring 2 and the outer ring deforms radially over a predetermined amount, the abutting portions abut on each other, thereby relieving or reducing the load acting on the contact portions of the track surface 2aof the outer ring 2, the rolling elements 3 and the track surface 2aof the shaft 1. In the first embodiment, the abutting portions 1c, 1dare constituted by annular projections located along the periphery of the shaft 1 adjacent to both axial ends of the track surface 1a. The outer ring 2 has an inner cylindrical surface of a constant diameter, and the ring portions 2b, 2cadjacent to the track surface 2aserve as the abutting portions. The rolling contact device shown in FIG. 1 is used in such a manner that the shaft 1 is secured to a machine element (not shown) at the of the shaft, while the outer ring 2 is placed in contact with a cam, rail or the like. When a radial load F greater than a predetermined value is applied to the outer ring 2 while the ring 2 is in a rotating or not-rotating state, the radial deformation of the outer ring 2 towards the shaft 1 becomes equal to the gap G, and the abutting portions 2b, 2cabut on the abutting portions 1c, 1d. In this state, a part of the radial load is directly transferred to the shaft 1 through these abutting portions, thereby relieving or reducing load acting on the rolling contact portions of the device. If a rolling contact device does not have the abutting portions 1c, 1d, 2b, 2c, the relation between a radial elastic deformation δ(mm) of the outer ring 2, maximum load Qm (kgf) acting on the rolling element, and an effective length La (mm) of each rolling element, is expressed, similarly to the case of a roller bearing, by the following equation: ##EQU1## Assuming that a radial load corresponding to the basic static nominal load Co (kgf) of the device acts on the outer ring 2, the maximum load Qm on each rolling element can be calculated by the following equation (2), which Z designates the number of the rolling element 3. In such a rolling contact device of bearing under an usual operation, it is experimentally recognized that a deformation of a rolling element or a roller smaller than 1/10000 of the rolling element diameter is permitted without causing any operational trouble. Accordingly, a static load causing such permanent deformation is referred to as a basic static nominal load. ##EQU2## The elastic deformation δof the outer ring 2 deduced from equations (1) and (2) is based on the assumption that no abutting portions 1c, 1d, 2b, 2care provided and a basic static nominal load is applied. By arranging the abutting portions 1c, 1d, 2b, 2cso as to make the gap G smaller than this elastic deformation δ, when a basic static nominal load is applied, the abutting portions 2b, 2calways abut on abutting portions 1c, 1d, thereby relieving the load acting on the rolling contact portions. In consequence, the above-mentioned gap G is preferred to be below the elastic deformation. In actual operation of the device, it is desired for the abutting portions 2b, 2cto slide along the abutting portions 1c, 1dwith a lubricant oil present in the gap G, similar to the case of a plane bearing. In such a case, the amount or size of the gap G is preferred to be a little greater than the sum of the elastic deformation of the outer ring caused when a maximum radial load (design load) is applied thereto in an usual operation of the device, and the allowable minimum thickness of a lubricant oil film for effecting a fluid lubrication. FIG. 2 shows a relation between a radial load F (kgf) acting on the rolling elements and an outer ring deformation δ(mm). In the FIG., line X shows a theoretical characteristic of a device of a prior art which has no abutting portions such as lc, ld,2b, 2c. Line Y shows an example of a characteristic of the illustrated embodiment having the abutting portions 1c, 1d, 2b, 2c. Line Y shows a characteristic of the rolling contact device according to the illustrated embodiment of the present invention, where the size or depth of the gap G is made equal to the sum δ 3 of the outer ring maximum deformation δ, resulted from maximum radial load applied to the outer ring during usual operation and minimum allowable thickness δ 2 of the lubricant oil. As obvious from line X in FIG. 2, in the prior art, the deformation of the outer ring linearly increases substantially in proportion to the increase of the radial load, and reaches δ 4 when a radial load corresponding to the basic static nominal load Co acts on the outer ring. In an usual operation, that is in a radial load range below point Cb which corresponds to the outer ring displacement δ 1 , line X coincides with line Y, in other words, the function of the device of the present invention is identical to that of the device of the prior art. In the range between point Pb and point Pc at which the radial load is Cc and the deformation of the outer ring reaches the value δ 3 , the gap G gradually decreases from the allowable minimum thickness of the lubricant oil film. In this range, since the abutting portions 2b, 2cabut on the abutting portions 1c, 1dwith an oil film interposed therebetween the deformation of the outer ring increases along a gentle slope as the load increases. When the radial load reaches Cc corresponding to point Pc, the abutting portions 2b, 2cdirectly contact with the abutting portions 1c, 1dwith no oil film therebetween. When the radial load further increases beyond point Cc, the deformation of the outer ring linearly increases along a slope gentler than the above-mentioned slope between point 0 and point Pb due to the greater stiffness of the rolling contact device. In consequence, the basic static nominal load corresponding to the outer ring displacement δ 4 is Co in the prior art, while in the illustrated embodiment as indicated by line Y, it is Cx which is considerably greater than Co. As mentioned above by referring to FIG. 2, since the outer ring deformation reaches δ 4 only when a greater load Cx is applied on the ring, permanent deformations of the rolling contact portions assumed to be caused by an impact load applied on the outer ring can be effectively prevented. Referring to line Y, in the range from Pb to Pc, the oil film gradually becomes thinner with an increasing frictional force accompanied, while in the range from Pc to Px, the abutting portions 2b, 2cdirectly abut on the abutting portions 1c, 1dwith no oil film therebetween, making it difficult for the outer ring to rotate. Therefore, when a radial load greater than Cb, particularly the load greater than Cc, is applied on the outer ring which is in a rotating state, the rotation of the ring may be abruptly stopped in an inconvenient manner. Consequently, it may be said that the rolling contact device of the present invention is most suitable to be used for a device sufferring an impact load which may be applied in a stationary state of the device., For example, the rolling contact device of the present invention may be used in an intermittent index device which transforms a continuous rotary motion of an input shaft to an intermittent rotary motion of an output shaft through a cam and rolling contact devices. In this case, there is the possibility that a large radial impact load may be applied to the outer rings of the rolling contact devices during the intermittent period for which the output shaft and hence the outer rings are in a stationary state, but no permanent deformation of the rolling contact portions may be caused by the impact load. Line Y in FIG. 2 corresponds to a case where the gap G is made equal to the outer ring deformation δ 3 . However, the gap G may also be selected to be greater than the elastic deformation δ 3 , as mentioned before. FIG. 3, FIG. 4 and FIG. 5 show second, third and fourth embodiments of the present invention, respectively. In the second embodiment shown in FIG. 3, annular abutting portion 1cand the opposite abutting portion 2bprovided in the first embodiment shown in FIG. 1 are omitted, and a flange portion 2bis provided on the shaft 1 for abutting on the left end of the rolling elements 3. On the other hand, similarly to the first embodiment, shaft 1 is formed with an annular projection or abutting portion ldadjacent to the right end of the rolling elements 3, which is opposite to abutting portion 2cof the outer ring 2. In the third embodiment shown in FIG. 4, the shaft 1 track surfaces 1aand 1aaxially separated from each other. A plurality of rolling elements 3' are arranged around the track surface la`, while a plurality of rolling elements 3"are arranged around the track surface 1a". The outer ring 2 having the track surface 2ais arranged around these rolling elements 3' and 3". The shaft 1 is formed with an annular projection 1edisposed between the track surface 1a`and the track surface 1a", which constitutes an abutting portion of the shaft 1. The outer ring portion opposite to the projection 1ewith a small gap G constitutes an abutting portion 2dof the outer ring 2. In the fourth embodiment shown in FIG. 5, the shaft 1 has a left end portion which has a substantially constant outside diameter greater than that of the right side portion of the shaft, and rolling elements 3 and outer ring 2 are mounted on this left end portion. In this fourth embodiment, the bottom surface of an annular groove formed in the inner surfaces of the outer ring 2 constitutes a track surface 2aof the outer ring 2, the outer ring portions adjacent to the ends of the track surface 2aconstitute abutting portions 2b, 2cof the outer ring 2, and the shaft portions opposite to the abutting portions 2b, 2cconstitute abutting portions 1c, 1dof the shaft 1. Since in the second, third and fourth embodiments, the features other than those described above are similar to those of the first embodiment, such similar features are indicated by the same reference numbers or marks, and detailed descriptions thereof are omitted. The gap G is determined in the second, third, or fourth embodiment similarly to the first embodiment. FIG. 6 shows a fifth embodiment of the present invention. The rolling contact device of this embodiment is of a so-called roller follower type, and comprises a shaft 10 having a constant diameter and a track surface 10aat its periphery, an outer ring 12 having a constant inside diameter and a track surface 12a, and a plurality of rolling elements 13 disposed 5 between the shaft and the outer ring at circumferential intervals and in rolling contact with the track surfaces 10aand 12a. The shaft 10 is formed with annular projections adjacent to the both ends of the track surface 10a, which constitute abutting portions 10c, 10dof the shaft 10. Outer ring portions opposite to the abutting portions 10c10d constitute abutting portions 12b, 12cof the outer ring 12 with a small gap G formed therebetween. FIG. 7 shows a sixth embodiment of the present invention. In this embodiment, the shaft 10 is not formed with any annular projections such as the abutting portions 10c, 10dseen in the fifth embodiment. Instead, an outer ring 12 is formed with an annular inner groove, the bottom of which constitutes a track surface 12a, and outer ring portions adjacent to the both ends of the track surface 12aconstitute abutting portions 12b, 12c. Portions of shaft 10 opposite to the abutting portions 12b, 12cconstitute abutting portions 10c, 10 dof the shaft 10 with a small gap G formed therebetween. Other features of the sixth embodiment are similar to those of the fifth embodiment. The size of the gap G in the fifth and sixth embodiments is determined in the same manner as in the first embodiment. As mentioned above, the rolling contact device of the present invention brings about such advantages as to a decrease of the probability of permanent deformations of the device at its rolling contact portions, when an impact load of the like acts on the outer ring of the device.

A rolling contact device having a shaft adapted to be secured to an element of an apparatus, an outer ring adapted to be in rolling contact with another element of the apparatus, and rolling elements disposed between the shaft and the outer ring, includes an abutting portion provided on each shaft and the outer ring, the abutting portions on the shaft and the outer ring being opposed to each other with a small gap defined therebetween. These abutting portions are arranged such that, when an excessive radial load is applied to the outer ring, the abutting portions are brought into contact with each other to prevent permanent deformation of rolling contact portions of the device.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is related to the co-filed U.S. applications entitled “MUTUAL INDUCTANCE IN TRANSFORMER BASED TANK CIRCUITRY”, “FABRICATION OF INDUCTORS IN TRANSFORMER BASED TANK CIRCUITRY”, and “FLUX LINKED LC TANK CIRCUITS FORMING DISTRIBUTED CLOCK NETWORKS” filed on Jul. 19, 2005, which are invented by the same inventor as the present application and incorporated herein by reference in their entireties. BACKGROUND OF THE INVENTION [0002] Electronic consumer products are pushing both the bounds of computation complexity and high clocking frequencies. The systems that are experiencing these problems include: VLSI (Very Large Scale Integration), microprocessors, ASIC's (Application Specific Integrated Circuit), SOC (System On a Chip) and FPGA's (Field Programmable Gate Arrays). All of these systems operate at clock frequencies that increase dramatically each year. This higher clock frequency coupled with the increased size of the die creates some fundamental problems in heat removal from the die and clock distribution over the surface of the die. [0003] The power dissipation typically follows the rule: P = 1 2 ⁢ CV 2 ⁢ f ( 1 ) which for a 1 pF load being clocked at a frequency of 10 GHz is 7.2 mW. Adiabatic techniques can reduce these power dissipation levels. It would be worthwhile to investigate if these techniques can be used advantageously to help solve these problems. [0004] Some of the basic circuit blocks to help achieve the ability for mobility, low power, and high computation require the necessity of a clock oscillator block. Tank circuits have been used to generate oscillatory clock signals. These circuits use LC (inductor-capacitor) elements to form the tank circuit and they have the adiabatic quality that may be used to reduce the power dissipation. [0005] For example, U.S. Pat. No. 5,396,195 issued Mar. 7, 1995 to Gabara proposed a basic LC tank circuit in an MOS technology. The circuit consists of a tank circuit driven by a cross-coupled MOS circuit. The oscillations generated by the MOS LC tank circuit fabricated in a 0.9 um CMOS technology operated with a supply voltage of 3.3V. The power dissipation was reduced by a factor of a 10× when a capacitive load was driven using an LC tank circuit as compared to being driven using conventional digital techniques. This circuit has been used in a multitude of applications ranging from wireless to on-chip clock generation modules. Many of the inductors used in this type of tank circuit have the form of the horizontal planar inductor as illustrated in FIG. 1 a and FIG. 1 b . These type of inductors typically require a large amount of area to form the inductor. [0006] The calculation of the values of planar inductors are provided in a published paper, “Simple Accurate Expressions for Planar Spiral Inductances”, IEEE J. Solid-State Circuits, Vol. 34, No. 10, Oct. 1999, by Mohan et al., hereafter referred to as the “Mohan” reference. [0007] In addition, the Q or quality factor of these inductors that are fabricated in CMOS are typically low. The quality factor or Q is a primary parameters in the evaluation of tank circuits. Q = 2 ⁢ π ⁢ Maximum ⁢   ⁢ energy ⁢   ⁢ stored ⁢   ⁢ in ⁢   ⁢ tank ⁢   ⁢ circuit Energy ⁢   ⁢ dissipated ⁢   ⁢ per ⁢   ⁢ cycle ( 2 ) [0008] The Q indicates the amount of energy dissipated by the tank circuit to maintain oscillations. The tank circuit is more energy efficient as the value of the Q term increases which indicates that the energy dissipated in the tank circuit decreases. One way to decrease the dissipation is to reduce the parasitic resistance of the inductor. [0009] An oscillator block provides the ability to regulate the flow of computation data within a VLSI (Very Large Scale Integration). For instance, the on chip clock frequency of a high-end microprocessor is expected to reach 10 GHz before the end of this decade. In addition, the power dissipation for the microprocessor is expected to be about 200 W, where the clock network will consume almost half of this power or 100 W. Thus, for this microprocessor, the higher frequencies and larger power dissipation values indicate a need to have clock circuits that can easily generate a 10 GHz signal and should be able to reduce the power dissipation of the clock network. The clock network of these VLSI chips typically contains large values of capacitance that need to be driven. [0010] Currently, H-trees are used to distribute clocks over the surface of a die. Almost half of the power dissipated in chip designs occurs in the clock network of VLSI and microprocessor chips. This is largely due to the capacitive and resistive load of the clock network. [0011] Several authors have addressed the clocking issue to determine achieve lower power, lower skew, and higher frequency of operation. [0012] In O'Mahony et al., a U.S. PGPUB. 2003/0001652 A1 published Jan. 2, 2003, they use a hierarchical clock distribution. The clock is sent to a plurality of clock grids by way of transmissions lines, and then each grid distributes the clock to the load. They use salphasic clocking which takes advantage of standing waves along a transmission line. The position of the receiver points must conform to positions that are multiple of one-half wavelength from one another dependant on the clock frequency. This will lock the frequency of the die into a range dependant on the half-wavelength. The loads however do not have to obey this constraint. [0013] In Galton et al., “Clock Distribution Using Coupled Oscillators”, Proceeding of the 1996 IEEE Inter. Symp. On Circuits and Systems, May 12-15, Vol. 3, pp. 217-220, they suggest using strongly coupled RC oscillators to distribute a clock signal over the die. Their technique uses transmission line that can be less than a quarter of a wavelength long. In addition, the transmission line can be lossy to couple the RC oscillators. Injection locking is used to lock all the oscillators in frequency. [0014] In Hall et al., “Clock Distribution Using Cooperative Ring Oscillators”, Proc. IEEE 17 th Conf. Advanced Research in VLSI, 1997, pp. 62-75, a cooperative ring oscillator is used to distribute a clock signal within the die. They also provide multiple clock phases in the distribution. Their circuit expands the ring oscillator from a simple ring to an N-dimensional mesh. This array does not have to be regular. One of the concerns is aggregation that is the non-ideal characteristic variations of the VLSI interconnect. This is a concern since interconnect that is used to connect the inverters of the ring oscillators. This factor dissipates power and introduces skew into the network. [0015] In Wood et al., “Rotary Travelling-Wave Oscillator Arrays: A New Clock Technology”, IEEE J. Solid-State Circuits, Vol. 36, No. 11, November 2001, a rotary traveling wave oscillator array is presented. It consists of a balanced set of transmission lines with distributed CMOS latches to power the oscillation and ensure rotation lock. A waveform propagates along the balanced transmission line that is looped at its ends so that the wave continues to propagate. In their design it is important that careful attention is required to guard against magnetic field coupling between the clock conductors since it will affect the potential performance of their oscillators. [0016] The technique presented here does not need to be constrained by half-wavelength or quarter-wavelength considerations as in O'Mahoney or Galton. In addition, Galton suffers from lossy transmission lines that are used to couple the RC oscillators together as well as the loss in the RC oscillator. As pointed out by Hall, the power dissipation in their technique is an issue for two factors; the ring oscillators dissipates power and the propagation of the signals in the interconnect dissipate power. The technique presented here uses adiabatic techniques to help overcome the particular losses of Hall and Galton. Finally, in Wood, magnetic field coupling is an undesirable condition; the technique presented here thrives on magnetic field coupling. [0017] The need for frequency adjustment of an array of oscillators is an important factor to overcome the limitation of any clock distribution network that is based on a wavelength-based layout. The wavelength-based layout will have a limited range of tuning and it would be desirable to extend the tuning range of a distributed clock network. The technique presented here provides such an outlet. BRIEF SUMMARY OF THE INVENTION [0018] Clock networks and clock generation in VLSI chips is a critical issue to high performance circuit operation. The distribution and minimization of power dissipation of the clock network is an important consideration when designing VLSI circuits. The adiabatic behavior of resonant circuits can be utilized to help resolve both of these designs considerations. Inductors and capacitors play a key role in energy recycling and distribution. The CMOS tank circuit or oscillator serves as the fundamental building block to create, distribute and maintain high frequency behavior in VLSI designs at low power dissipation levels. [0019] The basic invention is connect many CMOS tank circuits together and use the electrical and flux linkage of the resonant circuits to achieve a unified circuit behavior that is beneficial to the generation and propagation of clock signals over a surface region of the VLSI die. Thus, this network will distribute and synchronize a clock signal over the surface of a die. The need arises to be able to adjust the frequency of operation of the network. For instance, the effect of process, voltage and temperature variations may need to be compensated. [0020] Yet another aspect of this invention is to adjust the frequency of an oscillator and LC tank circuits using several different techniques. A Finite State Machine in conjunction with a comparator circuit can be used to test and adjust the frequency of each of the oscillators. In one case a global coarse adjustment can be performed to move the target frequency of the entire clock array. This allows the movement of the frequency of operation of the entire array at once. In another case, a passive flux linkage circuit can be used to adjust the frequency of operation. This method can adjust the frequency by almost a factor of two. Finally, a mechanical flux linkage a circuit is described that can be used to adjust the frequency of a system of oscillators. This can also adjust the frequency by a factor of two. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0021] FIG. 1 a - b illustrates two planar inductor structures. [0022] FIG 1 c presents a view of a planar inductor that has a helix structure. [0023] FIG. 1 d depicts an equivalent circuit for the planar inductor shown in FIG. 1 a - b. [0024] FIG. 1 e provides the calculated parameters of several inductors with a width of 20 μm. [0025] FIG. 1 f provides the calculated parameters of several inductors with a width of 10 μm. [0026] FIG. 2 a shows an inductor-capacitor circuit configured as a Colpitts oscillator and connected to a regenerative circuit. [0027] FIG. 2 b shows a inductor-capacitor oscillator and connected to a regenerative circuit in accordance with the present invention. [0028] FIG. 3 shows a Hartley oscillator connected to a regenerative circuit. [0029] FIG. 4 a - f shows several examples of a regenerative circuit. [0030] FIG. 4 g - h depicts regenerative circuits in accordance with the present invention. [0031] FIG. 5 a shows circuit schematics where an inductor, capacitors and regenerative circuit are combined together. FIG. 5 b depicts circuit schematics where an inductor, capacitors and controllable regenerative circuit are combined together in accordance with the present invention. [0032] FIG. 5 c provides a simplified circuit representation of FIG. 5 a . [0033] FIG. 5 d illustrates a simplified circuit schematic of FIG. 5 b in accordance with the present invention. [0034] FIG. 6 a provides a simplified circuit representation of FIG. 5 a . [0035] FIG. 6 b - c depicts an open loop and closed loop LC tank circuit in accordance with the present invention. [0036] FIG. 6 d depicts the simulated waveforms of the open loop and closed loop LC tank circuit in accordance with the present invention. [0037] FIG. 7 a depicts a three-stage open loop LC tank circuit in accordance with the present invention. [0038] FIG. 7 b show the simulated waveforms of the three-stage open loop LC tank circuit in accordance with the present invention. [0039] FIG. 7 c depicts a there-stage closed loop LC tank circuit in accordance with the present invention. [0040] FIG. 7 d show the simulated waveforms of the three-stage closed loop LC tank circuit in accordance with the present invention. [0041] FIG. 8 a depicts a four-stage closed loop LC tank circuit in accordance with the present invention. [0042] FIG. 8 b depicts a the inductor connectivity in the four-stage closed loop LC tank circuit in accordance with the present invention. [0043] FIG. 8 c provides the simulated waveforms of the four-stage closed loop LC tank circuit in accordance with the present invention. [0044] FIG. 9 a depicts a five-stage closed loop LC tank circuit in accordance with the present invention. [0045] FIG. 9 b provides the simulated waveforms of the five-stage closed loop LC tank circuit in accordance with the present invention. [0046] FIG. 10 a depicts a seven-stage closed loop LC tank circuit in accordance with the present invention. [0047] FIG. 10 b provides the simulated waveforms of the seven-stage closed loop LC tank circuit in accordance with the present invention. [0048] FIG. 11 a depicts a balanced closed loop LC tank circuit in accordance with the present invention. [0049] FIG. 11 b - c shows the simulated waveforms of the balanced closed loop LC tank circuit in accordance with the present invention. [0050] FIG. 12 a provides a balanced three-phase closed loop LC tank circuit in accordance with the present invention. FIG. 12 b depicts the simulated waveforms of the balanced three-phase closed loop LC tank circuit in accordance with the present invention [0051] FIG. 13 a provides a two-stage balanced closed loop with active transistors in an LC tank circuit in accordance with the present invention. [0052] FIG. 13 b - c depicts a simplified circuit representation of a single component of the two-stage balanced closed loop with active transistors in an LC tank circuit in accordance with the present invention [0053] FIG. 13 d provides a simplified block diagram of a two-stage balanced closed loop with active transistors in an LC tank circuit in accordance with the present invention. [0054] FIG. 13 e illustrates the waveforms of a two-stage balanced closed loop with active transistors in an LC tank circuit in accordance with the present invention. [0055] FIG. 14 a provides a three-stage balanced closed loop with active transistors in an LC tank circuit in accordance with the present invention. [0056] FIG. 14 b illustrates the waveforms of a three-stage balanced closed loop with active transistors in an LC tank circuit in accordance with the present invention. [0057] FIG. 15 a provides a four-stage balanced closed loop with active transistors in an LC tank circuit in accordance with the present invention. [0058] FIG. 15 b illustrates the waveforms of a four-stage balanced closed loop with active transistors in an LC tank circuit in accordance with the present invention. [0059] FIG. 16 a provides a simplified circuit representation of FIG. 5 a . [0060] FIG. 16 b depicts a regenerative circuit connected to a physical inductor. [0061] FIG. 17 a illustrates two instances of a regenerative circuit connected to a physical inductor where the inductors have flux linkage in accordance with the present invention. [0062] FIG. 17 b illustrates a circuit representation of two instances of a regenerative circuit connected to an inductor where the inductors have flux linkage in accordance with the present invention. [0063] FIG. 17 c shows the simulation waveforms of two instances of a regenerative circuit connected to an inductor where the inductors have flux linkage in accordance with the present invention. [0064] FIG. 17 d illustrates a circuit representation of two instances of a regenerative circuit connected to a inductor where the inductors have a reversed flux linkage in accordance with the present invention. [0065] FIG. 17 e shows the simulation waveforms of two instances of a regenerative circuit connected to an inductor where the inductors have a reversed flux linkage in accordance with the present invention. [0066] FIG. 18 illustrates four instances of a regenerative circuit connected to a physical inductor where the inductors have flux linkage in accordance with the present invention. [0067] FIG. 19 a depicts a circuit representation of one instance of a regenerative circuit connected to two inductors where the inductors may have flux linkage in accordance with the present invention. [0068] FIG. 19 b shows the physical layout of one instance of a regenerative circuit connected to two physical inductors where the inductors may have flux linkage in accordance with the present invention. [0069] FIG. 20 a depicts the physical layout of two instances of a regenerative circuit connected to two inductors where the inductors have flux linkage in accordance with the present invention. [0070] FIG. 20 b shows the circuit representation of two instances of a regenerative circuit connected to two inductors where the inductors have flux linkage in accordance with the present invention. [0071] FIG. 21 a presents the circuit representation of eight instances of a regenerative circuit connected to two inductors where the inductors have flux linkage in accordance with the present invention. FIG. 21 b depicts the physical layout of eight instances of a regenerative circuit connected to two inductors where the inductors have flux linkage in accordance with the present invention. [0072] FIG. 21 c illustrates the simulation waveforms for the physical layout of eight instances of a regenerative circuit connected to two inductors where the inductors have flux linkage in accordance with the present invention. [0073] FIG. 21 d illustrates a close-up region of the simulation waveforms for the physical layout of eight instances of a regenerative circuit connected to two inductors where the inductors have flux linkage in accordance with the present invention. [0074] FIG. 21 e shows a close-up region of the simulation waveforms for the physical layout of eight instances of a regenerative circuit connected to two inductors where the inductors have no flux linkage in accordance with the present invention. [0075] FIG. 21 f depicts the simulation conditions for the circuit in accordance with the present invention. [0076] FIG. 21 g presents the simulation results and predictive results for the circuit in accordance with the present invention. [0077] FIG. 22 a illustrates a circuit representation of one instance of a regenerative circuit connected to four parallel inductors where the inductors may have flux linkage in accordance with the present invention. [0078] FIG. 22 b illustrates the physical layout of one instance of a regenerative circuit connected to four physical inductors where the inductors may have flux linkage in accordance with the present invention. [0079] FIG. 23 a depicts a two-dimensional view of three instances of a regenerative circuit connected to a four rectangular physical inductors where the inductors have flux linkage in accordance with the present invention. [0080] FIG. 23 b shows a two-dimensional view of four instances of a regenerative circuit connected to a four rectangular physical inductors where the inductors have flux linkage in accordance with the present invention. [0081] FIG. 24 presents the connection of two coils each on a separate die that are connected together using solder bumps in a MCM technology in accordance with the present invention. [0082] FIG. 25 a illustrates the block diagram of a balanced eight-phase clock generator in accordance with the present invention. [0083] FIG. 25 b presents the circuit schematic of the block generating the φ1 signal in accordance with the present invention. [0084] FIG. 25 c depicts the physical layout of the balanced eight-phase clock generator in accordance with the present invention. [0085] FIG. 25 d shows an inductor layout with extended legs in accordance with the present invention. [0086] FIG. 25 e illustrates a three dimensional perspective of two inductors placed over one another in accordance with the present invention. [0087] FIG. 25 f presents two physical layouts of the balanced eight-phase clock generator where one is rotated 180° in accordance with the present invention. [0088] FIG. 25 g illustrates the relative placement of two physical layouts of the balanced eight-phase clock generator in accordance with the present invention. [0089] FIG. 26 a depicts the physical layout of sixteen instances of the balanced eight-phase clock generator where the inductors have flux linkage in accordance with the present invention. [0090] FIG. 26 b shows all 64-clock output waveforms of the physical layout given in FIG. 26 a during the time period around 10 nsec. [0091] FIG. 26 c shows all 64-clock output waveforms of the physical layout given in FIG. 26 a during the time period around 100 nsec illustrating the flux linkage synchronizing all outputs in accordance with the present invention. [0092] FIG. 26 d depicts the simulation conditions for the circuit in accordance with the present invention. [0093] FIG. 26 e presents the simulation results and predictive results for the circuit in accordance with the present invention. [0094] FIG. 27 illustrates the control circuitry to adjust the coarse and fine capacitance in several LC tank circuits in accordance with the present invention. [0095] FIG. 28 a depicts the schematic of a passive flux linkage frequency adjust circuit in accordance with the present invention. [0096] FIG. 28 b shows the simulation waveforms of a passive flux linkage frequency adjust circuit in accordance with the present invention. [0097] FIG. 28 c illustrates the use of a varactor to adjust the frequency of an LC tank circuit. [0098] FIG. 28 d illustrates the use of a switched array of capacitors to adjust the frequency of an LC tank circuit. [0099] FIG. 28 e illustrates the use of a enhancement mode transistor to adjust the frequency of an LC tank circuit. [0100] FIG. 28 f illustrates the use of a depletion mode transistor to adjust the frequency of an LC tank circuit. [0101] FIG. 29 illustrates a second control circuitry to adjust the coarse and fine capacitance in several LC tank circuits in accordance with the present invention. [0102] FIG. 30 a depicts the schematic of a mechanical flux linkage frequency adjust circuit in accordance with the present invention. [0103] FIG. 30 b shows the simulation waveforms of a mechanical flux linkage frequency adjust circuit in accordance with the present invention. [0104] FIG. 30 c illustrates the MEMS cross-sectional view of a mechanical flux linkage frequency adjust circuit in accordance with the present invention. [0105] FIG. 31 a depicts a top view of two instances of a physical layout of a single regenerative circuit that is parallel connected to four physical coils in accordance with the present invention. [0106] FIG. 31 b reveals a cross-sectional view of two instances of a physical layout of a single regenerative circuit that is parallel connected to four physical coils being synchronized by an external flux linkage-generating unit in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION [0107] The LC (inductor-capacitor) tank circuit has been a fundamental building block in many electrical system designs. This circuit is used in wireless, digital, and mixed-signal designs. The basic building elements of the LC tank circuit consist of at least one inductor and and at least one capacitor. [0108] The invention is based on the discovery that the flux linkage between inductors can be used to synchronize an interwoven network formed from individual LC tank circuits. The flux linkage that occurs between two inductors forms the basis of a structural unit known as a transformer. The coupling coefficient of the transformer can be utilized to lock an interwoven network of tank circuits so they operate in-phase. The ability to phase and frequency lock the interwoven network of tank circuits over the face of the die allows the generation of a unified clock waveform. The additional benefit is that the adiabatic nature of entire interwoven network reduces the power distribution of the clock network for a VLSI chip by over two orders of magnitude. [0109] In addition, several techniques are offered to control the frequency of operation of the interwoven network. In one case, a coarse and fine adjust capacitance is introduced into the tank circuit to directly alter the frequency. Anther method uses a passive load in a transformer configuration to adjust the frequency of operation of the primary LC tank circuit. And finally, the physical placement of a coil is adjusted within a transformer to alter the coupling coefficient to directly adjust the frequency of operation. [0110] Several basic examples of an LC tank circuit having a regenerative circuit that provides a negative resistance to compensate for the resistive loss of the inductance is provided. Three different regenerative circuits are described, where the third version allows the introduction of external signals to effect the operation of the circuit. [0111] Several assumptions are initially made to simplify the analysis of the inventive entity. This helps identify the key aspects of the invention without losing insight. The first one will be to assume that the self-inductances of the coils in the transformer are equal. The next assumption will assume that the capacitive load elements in a balanced tank circuit are equal. To be more specific, if a tank circuit generates a clock and a clock bar signal, the capacitive load attached to both of these nodes are identical. [0112] It is important to understand that setting these assumptions does not limit the range or scope of the inventive idea. Before a LC tank circuit is utilized in an actual operating system, each of the above assumptions will need to be re-evaluated according to the specifications of the design parameters. Those skilled in the art will recognize that the above assumptions do not limit the scope of the invention. [0113] FIG. 1 a illustrates a square inductor 1 - 1 with one turn. Note that this inductor has two leads, 1 - 4 and 1 - 5 , or ways of physically connecting the inductor to a circuit. The width of the metallic trace is shown as W. A two-turn inductor 1 - 2 is depicted in FIG 1 b . The measurements of the outside diameter is shown as d out , while the inside diameter is listed as d in . In addition, the distance between traces is identified as S. These type of inductors can occur in an IC (Integrated Circuit), a VLSI chip, an RF (Radio Frequency) chip, a PWB (Printed Wire Board), a MEMS (Micro-Electro-Mechanical-System) die or a MCM (Multi-Chip Module). The equivalent circuit representation 1 - 3 of the coils 1 - 1 and 1 - 2 are provided in FIG. 1 d . A simplified version of this equivalent circuit of an inductor will be utilized in many of the circuits analyzed in this paper to help describe the essential idea of this invention. [0114] FIG. 1 c depicts a helix structure used to form an inductor 1 - 3 . This inductor has two leads 1 - 6 and 1 - 7 . A single turn coil 1 - 12 is formed in a lower metal layer, then a via 1 - 8 is connect this coil to the single turn coil 1 - 11 in an upper metal layer. The via 1 - 9 connects the middle coil to the top coil 1 - 10 formed in an upper metal layer [0115] The inductors 1 - 1 , 1 - 2 and 1 - 3 are typical for the type of inductors found in a planar technology layout. These inductors are also called coils where coil can indicate that the conductor forming the inductor has a configuration that spans a portion of 360 degrees. [0116] In all of these planar inductors presented, several aspects were not shown. The substrate of the integrated circuit upon which these planar inductors are fabricated is not shown. In addition, the oxide or dielectric layer surrounding the metal layers is not illustrated. These simplified drawings provide an easier description of the structure of the inductor. The integrated circuit can typically have a plurality of metallization and dielectric layers. In addition, only a square inductor has been shown, however, those skilled in the art will realize that the inductor can be formed in a circular, oval, hexagonal or other shape, and still be within the scope of the invention. [0117] Finally, the tables listed in FIG. 1 e and FIG. 1 f displays the parameters of several inductors that were determined using the “Mohan” reference. The first column lists the values of the self-inductances L equ . The second column indicates N which indicates the number of turns of the coil. The next column gives d out that is the outside dimension of the coil. The remaining dimensions of din and W are also indicated. Note that one difference between FIG. 1 e and FIG. 1 f is that the width of the conductive trace used to form the coil is 20 μm and 10 μm, respectively. The number of squares forming the conductive trace of each inductor is indicated in the sixth column. The next column provides the parasitic resistor assuming that the sheet resistance of 0.01Ω□ is used. Finally, the last column gives the parasitic capacitance C OX of the inductors (see FIG. 1 d ). Note that this capacitance value is one half of the total parasitic value of the inductor. These inductors provide an indication of the real estate used for several one-turn inductors. In addition, several of these inductors will be simulated in different tank circuits to help describe the invention. [0118] The number of squares can be used with the sheet resistance value to determine an approximate resistance. The skin effect typically increases the resistance of the inductors proportional to the square root of frequency; however, the skin resistance effect will not be addressed in this discussion so that the concepts of the invention can be more easily visualized. For instance, the skin-depth in copper is about 0.66 μm at 10 GHz. Because of this effect, the current is carried near the surface causing the resistance to increase as mentioned earlier. [0119] An example of a Colpitts tank circuit oscillator 2 - 1 having a regenerative circuit 2 - 2 is given in FIG. 2 a . A regenerative circuit 2 - 2 is required to replace the energy lost by the dissipative process of energy flow through the resistive components within the tank circuit. If the regenerative circuit 2 - 2 was eliminated, the oscillations generated by the tank circuit 2 - 1 would eventually die out because of this resistive loss. The regenerative circuit can be formed out of active transistors; such as MOS transistors, CMOS transistors or BJT transistors. The regenerative circuit provides a negative resistance that cancels the parasitic resistance in the tank circuit. The regenerative circuit used is a type regen- 1 and, in addition, has a power and ground connection. The oscillator signal is generated across the two capacitors C 1 , and C 2 . Thus, this circuit has two outputs 2 - 3 and 2 - 4 that originate from the tank circuit. The signals that are developed across these two capacitors are 180 degrees out of phase with each other. [0120] FIG. 2 b illustrates a second version of the Colpitts oscillator 2 - 5 where the regenerative circuit 2 - 6 of type regen- 1 a has two additional inputs 2 - 7 and 2 - 8 . These inputs can be used to introduce other clock signals into the oscillator to control its phase generation. [0121] A Hartley oscillator 3 - 1 is shown in FIG. 3 . In total, this circuit requires at least two inductors. This regenerative circuit 3 - 2 is type regen- 2 and has a ground in this case, but as will be seen shortly may only contain a power connection. The regen- 2 has two outputs 3 - 3 and 3 - 4 that connect to the tank circuit. [0122] FIG. 4 illustrates several CMOS circuits configured in either regen- 1 , regen- 1 a or regen- 2 type regenerative circuits. Similar circuits can be designed using BJT transistors as well. In FIG. 4 a , a regen- 1 type circuit 4 - 1 is shown; here a p-channel 4 - 2 serves as a current source to the rest of the circuit. The two p-channel transistor 4 - 3 and 4 - 4 are cross coupled to each other; that is, the drain of 4 - 3 is connected to the gate of 4 - 4 and the drain of 4 - 4 is connected to the gate of 4 - 4 . This forms a regenerative circuit, note that the two transistors have the same conductivity type. The two n-channel transistors 4 - 5 and 4 - 6 are configured in a similar manner. The drain of 4 - 6 is connected to the gate of 4 - 5 and the drain of 4 - 5 is connected to the gate of 4 - 6 . This forms a second regenerative circuit. The tank circuitry is connected to the drains of the two cross coupled transistor circuits. In addition, the tank circuitry and the cross coupled transistors share the ground and power nodes. The output signal is provided at the two output nodes 4 - 7 and 4 - 8 . The negative resistance of the circuit compensates for the resistive loss in the tank circuit and allows the oscillation created in the tank circuit to be maintained. [0123] A regen- 1 type circuit 4 - 9 similar to the circuit 4 - 2 is given in FIG.4 b except that the p-channel current source has been removed. The circuit 4 - 9 provides the outputs 4 - 7 and 4 - 8 . [0124] An equivalent representation of the circuit 4 - 9 is provided in FIG. 4 c . This regenerative circuit 4 - 10 consists of two inverters connected head to tail as shown. This is also the basic building block of a ram-cell that is used to store memory in integrated circuits (IC). The outputs of this circuit 4 - 10 are indicated as 4 - 7 and 4 - 8 . This ram-cell has three states; outputs 4 - 7 and equal, output 4 - 7 is a logic “1” while output 4 - 8 is a logic “0”, and the case where output 4 - 7 logic “0” while output 4 - 8 is a logic “1”. The first state given is also know as the meta-stable state, where both outputs are equal. A slight bit of noise introduced into the circuit 4 - 10 under the meta-stable state condition will cause the circuit 4 - 10 to enter one of the remaining two states. [0125] The next three circuits are of type regen- 2 . In FIG. 4 d , only two cross-coupled n-channel transistors form the circuit 4 - 11 that is used to compensate for the resistive loss of the LC tank circuit. The outputs for this circuit are 4 - 13 and 4 - 14 . These are the two nodes connected to the LC tank circuit and any external load that is desired to be driven. [0126] The circuit shown in 4 - 12 of FIG. 4 e includes an n-channel current source 4 - 13 . Otherwise it is similar to the circuit of 4 - 11 . [0127] The circuit 4 - 14 illustrated in FIG. 4 f is the compliment of 4 - 11 , that is all the n-channels are replaced by p-channels and the VSS power supplies (ground) replaced by VDD supplies and vice-versa. [0128] The last two circuits are type regen- 1 a circuits. FIG. 4 g shows a regenerative circuit 4 - 15 where a p-channel 4 - 16 serves as a current source to the rest of the circuit. The two p-channel transistors 4 - 17 and 4 - 18 allow external signals to be introduced into the regenerative circuit. A regenerative circuit consists of the two cross-coupled n-channels 4 - 21 and 4 - 22 . The negative resistance of this circuit is provided to the LC tank circuit using the two outputs 4 - 19 and 4 - 20 . The negative resistance of the circuit compensates for the resistive loss in the tank circuit and allows the oscillation created in the tank circuit to continue. [0129] FIG. 4 h illustrates the second version 4 - 23 of the regen- 1 a circuit. This circuit is similar to the circuit in FIG. 4 g , except that the p-channel current source has been eliminated. [0130] FIG. 5 a depicts an LC tank circuit 5 - 1 . It contains a regenerative circuit generating two outputs 5 - 4 and 5 - 5 that drive two sets of balanced capacitive loads. A capacitor 5 - 2 combines all of the capacitance that is typically non-adjustable. This may include the parasitic capacitance of wire interconnections, the capacitance of the gate, drain, overlap capacitance of the transistors forming the regenerative circuit, the capacitance of the inductors 5 - 4 , and the capacitance of the gates or circuits being driven by the LC tank circuit. [0131] The capacitor 5 - 3 is an adjustable capacitor that is used to adjust the frequency of oscillation of the LC tank circuit. Some examples of frequency adjustment include a voltage-controlled varactor that can be formed using a diode or a MOS transistor. The MOS transistor can be configured as an enhancement or depletion mode transistor. By adjusting the control voltage to these transistors, the capacitance presented to the tank circuit can be modified, thereby, modifying the frequency of operation of the tank circuit. Another form of adjustable capacitor would include an array of MOS transistors. The array would present capacitance to the LC tank circuit through switches that can be controlled by a set of control voltages. By adjusting these voltages, one or many gates can be connected or disconnected to the LC circuit that in turn varies the effective capacitance presented to the LC tank circuit. The frequency of operation of the tank circuit changes according to equation (3) where only the values of C and L are used in the following formula: f = 1 2 ⁢ π ⁢ LC ( 3 ) [0132] FIG. 5 b shows a LC tank circuit 5 - 6 where the regenerative circuit type regen- 1 a is used. Inputs 5 - 7 and 5 - 8 can be applied to the gates of the two p-channel transistors. This circuit generates two outputs 5 - 9 and 5 - 10 . Similar to the previous circuit, this circuit contains both the constant capacitive load 5 - 12 and the adjustable capacitor 5 - 11 . [0133] FIG. 5 c presents a simplified model 5 - 1 of the LC tank circuit 5 - 1 given in FIG. 5 a . In addition, the two outputs of the circuit 5 - 4 and 5 - 5 are depicted. Although not shown in FIG. 5 c , the capacitive loads illustrated in FIG. 5 a are assumed to exist in this simpler representation of the circuit. The transistors have been modeled using a ram-cell circuit providing a compact representation of this LC tank circuit. The meta-stable state of the ram-cell combined with the parasitic resistance of the inductor shorting the two outputs 5 - 4 to 5 - 5 appears to make the meta-stable state more likely. To overcome this state, a start up circuit can be used to unbalance the two outputs. Startup circuits are well known in the art and will not be described further. This simple circuit representation 5 - 1 will be used to describe several inventive circuits that will be presented later. [0134] FIG. 5 d presents a simplified model 5 - 6 of the circuit given in FIG. 5 b . The input leads 5 - 7 and 5 - 8 are similarly labeled as before. In addition, the two outputs 5 - 9 and 5 - 10 are indicated. [0135] FIG. 6 a shows the basic LC tank circuit 6 - 1 used to describe several different LC tank circuits, hereafter called the “basic LC tank circuit.” This circuit has two outputs 6 - 2 and 6 - 3 . The circuit also contains (but not shown) the capacitor network of the adjustable and constant variety as mentioned in FIG. 5 . FIG. 6 b illustrates an open series connection 6 - 5 of two basic LC tank circuits. This circuit 6 - 5 contains three outputs; 6 - 2 , 6 - 3 and 6 - 4 . FIG. 6 c depicts a closed loop connection 6 - 7 of the circuit illustrated in FIG. 6 b . Note that output 6 - 4 collapses and becomes the output 6 - 2 . [0136] FIG. 6 d presents a simulation 6 - 6 of the basic LC tank circuit, the open and closed loop series connection of two of the basic LC tank circuits. The 10 GHz outputs 6 - 2 and 6 - 4 overlap one another while the output 6 - 3 is 180° out of phase with the two previous outputs. Thus, there is no difference in the outputs of the waveforms 6 - 2 and 6 - 3 for a single and dual connected basic LC tank circuit. [0137] FIG. 7 a illustrates three basic LC tank circuits configured in an open series connection 7 - 7 . This circuit contains four outputs; 7 - 2 , 7 - 3 , 7 - 4 and 7 - 5 . FIG. 7 b presents the simulation results of these four waveforms. Because of the open connection, every other output is similar. For example, waveforms 7 - 3 and 7 - 5 overlap each other, while waveforms 7 - 2 and 7 - 4 are generated 180° out of phase when compared to waveforms 7 - 3 and 7 - 5 . [0138] FIG. 7 c shows a closed loop connection of the three basic LC tank circuits 7 - 6 . Because the loop is closed, there are only three outputs; 7 - 7 , 7 - 8 and 7 - 9 . Also, note that one possible stable state occurs when the three outputs can be equal to one another. To avoid this situation, a startup circuit can be used to prevent this condition as mentioned earlier [0139] This circuit 7 - 6 generates a single-ended multi-phase output that is shown in FIG. 7 d . The waveforms are labeled to correspond to the nodes of the circuit 7 - 6 . Each output 7 - 8 , 7 - 9 and 7 - 7 has a phase separation of 120° or; θ = 360 ° n ( 4 ) from the adjacent waveform where n equals the number of outputs in the closed loop LC tank circuit. The oscillation signal can propagate either clockwise or counter-clockwise in the loop. Finally, the term single-ended implies that the outputs are not balanced. For example, the circuit 7 - 6 generates waveform 7 - 8 but does not generate a balanced signal that is 180° out of phase with the waveform 7 - 8 . [0140] FIG. 8 a illustrates a closed loop connection of four simple LC tank circuits connected in series 8 - 1 . This circuit has four outputs; 8 - 2 , 8 - 3 , 8 - 4 and 8 - 5 . The simulated waveforms 8 - 8 of these four outputs are provided in FIG. 8 c . The waveforms corresponding to outputs 8 - 2 and 8 - 4 overlap one another, while the waveforms of outputs 8 - 3 and 8 - 5 overlap each other and are 180° out of phase with the output waveforms 8 - 2 and 8 - 4 . [0141] FIG. 8 b illustrates the closed loop connection of the four inductors joined at the outputs 8 - 2 , 8 - 3 , 8 - 4 and 8 - 5 . These inductors provide an initial DC operating point to the circuit 8 - 1 time equals to 0. Assuming the inductors in the circuit 8 - 1 were removed, the series connection of the even number of ram-cells would cause the circuit 8 - 1 to enter a stable state. That is, adjacent outputs would latch into either a high or low state. Thus, the inclusion of the inductors into the circuit 8 - 1 provide the ability of an even number of series connected LC tank to oscillate with the limitation that the generated adjacent signals are 180° out of phase with each other. [0142] Note that when the closed loop contains an even number of LC tank circuits, the phase separation does not satisfy equation (4). This can be seen by comparing the arrows 8 - 8 , 8 - 9 , 8 - 10 and 8 - 11 in the circuit 8 - 1 against the plots of these outputs in the waveform simulation 8 - 12 . When the time equals 19.92 nsec, the dotted line 8 - 6 is used to help determine the direction of the arrows in the circuit 8 - 1 . During time 8 - 6 , the output waveforms 8 - 2 and 8 - 4 are increasing which is indicated by the upwards arrows 8 - 8 and 8 - 10 in circuit 8 - 1 . Similarly, the output waveforms 8 - 3 and 8 - 5 are decreasing as indicated by the downward arrows 8 - 9 and 8 - 11 in circuit 8 - 1 . In effect, all of the arrows in circuit 8 - 1 are 180° out of phase with its adjacent neighbor. Note that at time 8 - 7 all the waveforms converge to a point 8 - 9 . This corresponds to the case where all the transient outputs of the circuit 8 - 1 are equal. After the point 8 - 9 , the arrows in the circuit 8 - 1 flip polarity. [0143] FIG. 9 a depicts a closed loop series connection 9 - 1 of five basic LC tank circuits. The five outputs; 9 - 2 , 9 - 3 , 9 - 4 , 9 - 5 and 9 - 6 are labeled in the circuit 9 - 1 . The simulated waveforms for these five outputs are provided in FIG. 9 b which also shows that the oscillation signal propagates in a counter-clockwise direction in the loop. [0144] FIG. 10 a depicts a closed loop series connection 10 - 1 of seven basic LC tank circuits. The five outputs; 10 - 2 , 10 - 3 , 10 - 4 , 10 - 5 , 10 - 6 , 10 - 7 and 10 - 8 are indicted in the circuit 10 - 1 . The simulated waveforms for these seven outputs are provided in FIG. 10 b which also shows that the oscillation signal propagates in a counter-clockwise direction in the loop. [0145] FIG. 11 and FIG. 12 both present another form of an LC tank circuit. The circuit 11 - 1 in FIG. 11 a consists of a ram-cell generating outputs 11 - 2 and 11 - 3 , a second ram-cell generating outputs 11 - 4 and 11 - 5 , a first inductor connecting output 11 - 2 to 11 - 4 and a second inductor connecting output 11 - 3 to 11 - 5 . [0146] The simulation results for circuit 11 - 1 are provided in FIG. 11 b and FIG. 11 c . FIG. 11 b illustrates a stable state different from that described when the circuit given in FIG. 6 was covered. The circuit 11 - 1 can end in state where the ram-cells latch their outputs into a high and low state. FIG. 11 b shows the outputs 11 - 2 and 11 - 4 both ending in a high state, while the outputs 11 - 3 and 11 - 5 end in a low state. However, using a startup circuit, the circuit 11 - 1 can go into oscillation as indicated by the simulation results given in FIG. 11 c . When the circuit 11 - 1 oscillates, the simulated results show that outputs 11 - 3 and 11 - 4 overlap one another, while outputs 11 - 2 and 11 - 5 overlap each other and are 180° out of phase with the waveforms 11 - 3 and 11 - 4 . [0147] The circuit 12 - 1 in FIG. 12 a generates three balanced clock signals that are 120° out of phase with one another. Three ram-cells are placed between outputs 12 - 2 and 12 - 4 , 12 - 4 and 12 - 6 and 12 - 6 and 12 - 2 forming a ring structure located in the upper portion of circuit 12 - 1 . Another three ram-cells are placed between outputs 12 - 3 and 12 - 5 , 12 - 5 and 12 - 7 and 12 - 7 and 12 - 3 forming a second ring structure. Finally, inductors are positioned between outputs 12 - 2 and 12 - 3 , 12 - 4 and 12 - 5 , and 12 - 6 and 12 - 7 . A startup circuit insures that the circuit goes into oscillation. FIG. 12 b illustrates the waveforms at the outputs 12 - 2 , 12 - 3 , 12 - 4 , 12 - 5 , 12 - 6 and 12 - 7 . Note that the outputs located across each inductor generate a set of balanced output oscillation signals. [0148] FIG. 13 a illustrates two LC tank circuits 13 - 1 that are connected to each other. The outputs 13 - 2 and 13 - 3 of the upper LC tank circuit are cross connected to the gates of the two p-channels 13 - 7 and 13 - 8 in the lower LC tank circuit. In addition, the outputs of the lower LC tank circuit 13 - 4 and 13 - 5 are directly connected to the gates of the two p-channels 13 - 9 and 13 - 10 in the upper LC tank circuit. This circuit 13 - 1 generates a quadrature signal. Note that the circuit 13 - 1 uses the two sets of the regen- 1 a regenerative circuit. [0149] The upper LC tank circuit is drawn in the simplified form 13 - 6 that was given earlier as the circuit in FIG. 5 d and is redrawn in FIG. 13 b . The input signals 13 - 4 and 13 - 5 control the inverter symbols and correspond to the gates of the two p-channel transistors 13 - 9 and 13 - 10 . The outputs 13 - 2 and 13 - 3 are formed across the inductor. The circuit 13 - 6 is further simplified to the block diagram 13 - 11 depicted in FIG. 13 c . The input signals are 13 - 4 and 13 - 5 , while the output signals are 13 - 2 and 13 - 3 . The labeling of these signals are in agreement with the signal names given in FIG. 13 b and FIG. 13 a . [0150] The block diagram 13 - 11 is substituted for the circuits in FIG. 13 a to generate the equivalent block diagram 13 - 12 depicted in FIG. 13 d . The simulation results for this circuit are given in FIG. 13 e . Note that the output signals 13 - 3 and 13 - 2 generate the balanced 0° and 180° signals, while the outputs 13 - 5 and 13 - 4 generate the balanced 90° and 270° signals. [0151] A block diagram 14 - 1 that generates six balanced signals 14 - 2 , 14 - 3 , 14 - 4 , 14 - 5 , 14 - 6 , and 14 - 7 are illustrated in FIG. 14 a . The circuit 14 - 1 was simulated and the waveforms are presented in FIG. 14 b . The three sets of balanced signals are; the 0° and 180° signals 14 - 4 and 14 - 5 the 60° and 240° signals 14 - 7 and 14 - 6 , and the 120° and 300° signals 14 - 2 and 14 - 3 . [0152] Note that the outputs of each block feeding the next one do not cross one another as it did in the quadrature block diagram in FIG. 13 d . Thus, for an even balanced output signal generation, the outputs should cross an odd number of times. In an odd balanced output circuit, the outputs should cross an even number of times. [0153] FIG. 15 a shows a block diagram of an eight balanced output clock generator 15 - 1 . The outputs are 15 - 2 to 15 - 9 . Simulation results of the circuit in FIG. 15 a are given in FIG. 15 b . Note that there are four balanced sets of clock signals. Each output waveform is labeled to correspond to the output of the block diagram 15 - 1 . [0154] All of the previous circuits, block diagrams, and schematics provided the connectivity of several LC tank circuits to generate oscillations which could have multi-phase components. Such circuits are useful for RF designs, clock generation for VLSI chips, adiabatic circuitry, analog circuitry, and high-speed digital circuitry. The interconnectivity of these LC tank circuits were performed by a physical connection such as a metal interconnect. The next group of circuits will interconnect the LC tank circuits using the flux linkage between inductors or coils. [0155] Coils and inductors sometimes have the similar meanings. Inductors are metallic elements that have a self-inductance. Coils are also inductors, where the name coil can imply that the shape of the inductor has a circular twist in its physical structure. In addition, the word coil can be used when there may be more than one inductor in the system where the two inductors may form a transformer. Thus, the coils share a flux linkage and signals can be sent between the coils using this flux linkage that exists in a transformer. [0156] FIG. 16 a reproduces a circuit 16 - 1 that was shown in FIG. 5 c . The two outputs are 16 - 2 and 16 - 3 . The inductor 16 - 4 connects the two outputs. FIG. 16 b redraws the equivalent circuit but this time replaces the inductor with a metallic trace shaped as a coil 16 - 4 . The coil has a width W, an outside dimension d out , and an inside dimension d in . The coil is connected to the regenerative circuit by outputs 16 - 2 and 16 - 3 . Note that this coil only has one turn and the turn is rectangular and represents a basic cell. Those skilled in the art realize that the coil may have a variety of shapes; circular, hexangular, spiral, etc. In addition, the number of turns can be a portion of one or several turns. [0157] FIG. 17 a illustrates the physical placement for two of the basic cells given in FIG. 16 b . The area covered by this structure is 2d out by d out . Because of this placement, the flux produced by the coil 17 - 4 is linked to the coil 17 - 5 and vice versa. A circuit schematic 17 - 1 is given in FIG. 17 b representing the placement of the coils shown in FIG. 17 a . The circuit 17 - 1 illustrates the outputs of the upper regenerative circuit 17 - 2 and 17 - 3 and the connection to the coil 17 - 4 . The lower coil is indicated as 17 - 5 and connects to a second regenerative circuit generating outputs 17 - 6 and 17 - 7 . The coils link the upper and lower circuits. This flux linkage is also known as mutual coupling and is indicated by the symbol M and the double arrowed line. In addition, the dots on the coils indicated the induced voltage generated in each coil according to Lenz's Law. The combination of the double coil, the M symbol, and the dots are referred collectively as a transformer. In simulation tools, the coupling coefficient k is used to simulate the flux linkage. The mutual inductance M is related to the coupling coefficient k according to: M=k√{square root over (L 1 L 2 )}  (5) [0158] The circuit 17 - 1 was simulated and the results are indicated in FIG. 17 c . The inductance of both coils was assumed to be equal (L 1 =L 2 ) and the k in the simulator was set to 0.4. The waveforms at outputs 17 - 2 and 17 - 6 overlay one another. This result also agrees with the position of the dots. [0159] Furthermore, this simulation demonstrates that a clock signal can be synchronized over an area of the die. In this case, by reviewing the structural layout of FIG. 17 a , the area is 2d out ×d out . Thus, this illustrates one aspect of the invention: the flux linkage can be used to synchronize a clock signal over an area of the die. [0160] The dot position in the circuit 17 - 8 was modified as shown in FIG. 17 d where otherwise all the named nodes as compared to the circuit 17 - 1 remain the same. The simulation results are indicated by the waveforms shown in FIG. 17 e . Now the outputs 17 - 3 and 17 - 6 overlay one another. Thus, in a transformer, the flux linkage tends to force the oscillation at the dotted terminals to have the same phase. And furthermore, the flux linkage tends to force the oscillation at the dotted and un-dotted terminals to have a phase difference of 180°. [0161] FIG. 18 illustrates how a larger area can be encompassed by the placement of additional basic cells that are flux linked to at least the neighboring coils. Four coils; 18 - 10 through 18 - 13 are positioned near one another in an IC chip. The regenerative circuits generate the outputs; 18 - 2 through 18 - 9 . The total area is 2d out ×2d out . This concept can be extended across the entire surface of the die. [0162] The coil formation may occur in the upper layer metals of the die where the metal thickness can be made thicker so that the parasitic resistance of the metal trace forming the inductance can be minimized. Active circuitry which will be clocked by the oscillations generated by the LC tank circuits can be placed anywhere on the die if the active circuitry does not need these upper layers of metal for routing or forming interconnections between the active circuitry. However, if the active circuitry requires a partial use of these upper layers of metal then it would be desirable to increase the area of the coil without necessarily decreasing the frequency of operation. [0163] For example, referring to FIG. 1 e , the inductor in the first row has an inductance of 0.565 nH and a d in of 210 μm. The inductor in the second row has an inductance of 1.266 nH and a din of 460 μm. Thus, the second inductor has a little over twice the inductance but has an internal area (d in ×d in ) that is more than four times that of the first inductor. Using equation (3) reveals that the second inductor would drop the frequency of oscillation by a factor of 1/√{square root over (2)} while the internal area increases by a factor of 4. One approach to achieving a larger usable area while maintaining a higher frequency of operation is to use parallel connections of inductors. For example, look at the physical layout 19 - 1 of FIG. 19 b showing a second basic cell. This cell measures 2d out ×d out . Two inductors 19 - 2 and 19 - 5 are connected in parallel to a single regenerative circuit that generates two outputs 19 - 3 and 19 - 4 . Assume that the inductor in the second row of FIG. 1 e was used for the inductors 19 - 2 and 19 - 5 . The equivalent inductance of parallel-connected inductances is given by; 1 L 1 + … + 1 L n = 1 L equ ( 6 ) or the equivalent inductance is determined as 0.633 nH by using equation (6). This value of inductance approaches that of the inductance given in the first row. As mentioned earlier, the encompassed area of a single 1.266 nH inductor increased the area by a factor of 4× compared to the 0.565 nH inductor. Furthermore, since there are two of these encompassed areas enclosed by the inductors 19 - 2 and 19 - 5 . The overall encompassed area for this second basic cell using only one regenerative circuit is increased by 8× when compared to the prior basic cell consisting of a regenerative circuit connected to a single 0.565 nH inductor. Also note that the equivalent parasitic resistance of parallel-connected inductors is decreased as given by; 1 R 1 ⁢   +   ⁢ … ⁢   +   ⁢ 1 R n ⁢   =   ⁢ 1 R equ ( 7 ) so the resistance presented to the regenerative circuit is 0.467Ω as determined by using equation (7). This is very similar to the parasitic resistance value of the first inductor in the first row. Thus, the parallel combination of larger inductances or coils in an IC offers benefits of increasing the encompassed area. In addition, the frequency of operation and the value of parasitic resistance can maintain their initial values. Furthermore, only one regenerative circuit is necessary to drive two inductors that offers the potential benefit of decreasing the power dissipation since one regenerative circuit has been eliminated. These are all advantages of the second aspect of his invention. Although the parasitic capacitance increases by a factor of two, the power dissipation of driving this capacitance is adiabatic (because of the tank circuit) and is lower than the power dissipation arrived at by using equation (1). [0164] FIG. 20 a depicts the placement of two basic cells with the physical layout of 19 - 1 placed next to one another to form the physical layout 20 - 1 shown. The coils are 20 - 2 through 20 - 5 and the two regenerative circuits generate the outputs 20 - 6 through 20 - 9 . The schematic representation of the physical layout 20 - 1 is shown in FIG. 20 b . The numbering of the nodes and devices follows the convention used in FIG. 20 a . In particular, note that only two sets of dots are indicated on the transformers. Note that not all of the dots are shown so that the circuit is simplified. For example, depending on the level of the accuracy desired in the determination of the flux interaction (a CAD tool would be a useful addition to help determine the full interaction), there will be a k coupling interaction between coil 20 - 2 and the three coils 20 - 3 , 20 - 4 and 20 - 5 . A k coupling interaction will also occur between coil 20 - 3 and the two coils 20 - 4 and 20 - 5 . Finally, the coil 20 - 4 will have coupling interaction to coil 20 - 5 . Thus, for the above description there should be 6 sets of dots on the transformers. Furthermore, note that there are effectively six sets of transformers; 20 - 2 and 20 - 3 , 20 - 2 and 20 - 4 , 20 - 2 and 20 - 5 , 20 - 3 and 20 - 4 , 20 - 3 and 20 - 5 and finally 20 - 4 and 20 - 5 . This is a very simplified flux interaction between each coil and the other one. A more detailed flux interaction would occur if each coil was broken into several segments; and each of these segments interacted with all of the remaining segments. The number of transformers would increase dramatically thus showing the need for a CAD (Computer Aided Design) tool that would aid in the determination of all these calculations. [0165] FIG. 21 b illustrates a physical layout 21 - 1 that incorporates eight of the basic cells with the physical layout 19 - 1 given in FIG. 19 b . Each of the eight basic cells is labeled 21 - 2 through 21 - 9 . In addition, only one of the two outputs of each regenerative circuit is labeled 21 - 10 through 21 - 17 . The total size of this physical layout is 4d out ×4d out . An inductor from the first row of FIG. if was used; thus, the area is estimated at 1000 μm×1000 μm. [0166] A schematic circuit for the physical layout 21 - 1 is given in FIG. 21 a . Again note that only a fraction of the dot pairs are indicated. The numbering system used to identify the components in FIG. 21 a corresponds to those used in FIG. 21 b . [0167] FIG. 21 c provides the simulation result when the circuit of FIG. 21 a is simulated. Note that the waveforms of the eight outputs 21 - 10 through 21 - 17 start up randomly and then at about 2 nsec the outputs start to synchronize and overlap one another. As pointed by the arrow, all eight waveforms are in unison. Thus, the flux linkage between the coils can be used to synchronize the clock oscillation circuits between several interacting coils over a region of a die. The flux linkage allows the clock network to exchange information so that the clock oscillation circuits can self-align their clock outputs and become synchronized. [0168] FIG. 21 d illustrates a close-up of the eight outputs 21 - 10 through 21 - 17 . The skew between these eight signals is about 3 psec. This result is very promising since this value is only about 2.4% of the 125 psec period or for the clocks running at 8 GHz. [0169] FIG. 21 e depicts the situation when all the k coupling coefficients are reduced to 0. Thus, there is no interaction between the eight LC tank circuits. As can be seen, the waveforms of the eights outputs spread out over the period dependant only on the initial conditions that were applied to each LC tank circuit before time t=0. [0170] FIG. 21 f provides a table 21 - 18 indicating the simulation conditions when the circuit in FIG. 21 a representing the physical layout 21 - 1 was simulated in SPICE. The frequency of operation of the layout was targeted at 8 GHz and is an expected frequency of future VLSI and μprocessor chips. The process was a 0.13 μm CMOS technology having a core VDD of 1.2V. A sheet resistance of 0.01Ω□ was used for the coils, while each of the inverters had a p-channel width of 30 μm and an n-channel width of 15 μm. The inductor was selected from the first row of the table given in FIG. 1 f . The inductance of each individual coil was 0.633 nH and had a parasitic resistance of 0.868Ω. Because two inductors were placed in parallel in each cell, equations (6) and (7) were used to determine that the equivalent inductance and resistance is 0.322 nH and 0.434Ω, respectively. The k coupling coefficient value ranged from 0.4 to 0.03 dependent on the relative placement between two coils. [0171] FIG. 21 g gives a table 21 - 19 that uses the results of the current simulation of the physical layout 21 - 1 to determine expected parameters when the physical layout is increased in size to a die size of 1.6 cm×1.6 cm. The area of one of the eight cells in the physical layout is 500 μm×250 μm. The total area of the layout 21 - 1 in FIG. 21 b is 1,000 μm×1,000 μm, while the size of the μprocessor chip is 16,000 μm×16,000 μm. This data can be used to estimate the number of cells required in the μprocessor. In the layout 21 - 1 , 8 basic cells were placed together. A simple calculation indicates that the μprocessor would require 2048 cells to cover the surface of the die. [0172] Each basic cell contains a regenerative circuit and as indicated earlier has a balanced output that drives a capacitive load consisting of parasitic and adjustable components. In this simulation, each output had an additional capacitive load of 0.5 pF connected to each output; part of which accounts for the two parallel-connected inductors that have a capacitive load of 0.35 pF. In addition, the gate and drain capacitance of the transistors within the regenerative circuit adds another 0.6 pF. The capacitance load that each output of the basic cell drives is approximately is 1.1 pF while the total capacitance each cell drives is 2.2 pF. However, since the transistor parasitics will not change significantly in a given technology, their contribution of “drivable” capacitive load will be subtracted from the 2.2 pF figure leaving about lpF of “drivable” load. The capacitive load of the inductor was not subtracted from this figure because it is possible that the inductor can be fabricated off-chip (MCM, for example) and may have a lower capacitance. Thus, the total “drivable” capacitance is 1 pF and the total “drivable” capacitance of the layout 21 - 1 would be 8 pF. The corresponding capacitive value for the μprocessor is 2048 pF as indicated in the table. [0173] The power per cell was simulated to be 2 mW. Thus, the total power for the layout 21 - 1 is 16 mW while the μprocessor would dissipate about 4.1 W. [0174] The idea of placing more than two parallel inductors across a single regenerative circuit 22 - 1 is illustrated in FIG. 22 b . Four inductors 22 - 4 through 22 - 7 are positioned in four quadrants and connected to the regenerative circuit that generates the outputs 22 - 2 and 22 - 3 located at the origin. A schematic representation of the physical layout is shown in FIG. 22 a . The numbers correspond to the same element between the two diagrams. This type of structure allows a large inductor (both physically and numerically) to be used in 22 - 4 through 22 - 7 , yet due to equation (6) and (7), presents a much smaller inductance and resistance to the regenerative circuit. [0175] The parallel combination of inductors is useful for several reasons. First, the larger inductance value implies a physically larger inductor. For example, (see FIG. 1 e , bottom row) a 3.46 nH inductor has a d out of 1250 pm. Thus, the total size of the layout 22 - 1 would be 2500 μm×2500 μm. So, one regenerative circuit can be used to cover a large area. Second, the parallel combination reduces the resistance value from 4.868Ω to 1.434Ω. This helps reduce the size of the transistors in the regenerative circuit. The benefit is that the power dissipation decreases two ways: 1) smaller transistors that switch a load dissipate less power, 2) the leakage current is proportional to the size of the transistors, thus there would be less power dissipation due to leakage current. Third, the parallel combination reduces the inductance and allows a higher frequency to be achieved according to equation (3). [0176] To increase the k coupling coefficient, the adjacent inductors can be placed over the inductors of an adjacent cell. FIG. 23 a illustrates how a multi-level metallization can be used to increase the flux linkage. Assume that the physical layout or cell 22 - 1 is used in FIG. 23 a . The physical structure 23 - 1 shows two cells formed on a lower metal layer while a third cell is formed in an upper metal layer. Note the relative placement of the inductors from top cell in relation to the inductors of the remaining two lower cells. The top cell has two physical inductors 23 - 6 and 23 - 7 identified while the regenerative circuit is positioned at 23 - 3 . [0177] The active transistors within 23 - 3 may in fact be located in the semiconductor portion of the die. Thus, 23 - 3 can symbolically represent the regenerative circuit. In addition, there are dielectric or oxide layers between the metal layers that are not indicated, nor is the substrate indicated. Those with average skill in the art will appreciate that these layers can be incorporated without losing the meaning of this description. [0178] An inductor 23 - 5 from one of the lower cells is positioned under the inductor 23 - 6 of the top cell. In addition, an inductor 23 - 2 from the other lower cell is positioned under the inductor 23 - 7 of the top cell. Thus, the top cell has a flux linkage with two lower cells. This pattern can be extended to encompass all of the cells in both metal layers to create a strongly coupled interwoven flux linkage network that operates as a single unit. A feed forward continuous flux linkage path formed by the flux linkage and the electrical portions of the regenerative circuit would be the energy arriving at the regenerative circuit 23 - 4 , then being electrically sent to the inductor 23 - 5 , having a flux linkage path to the inductor 23 - 6 above it, sent electrically to the regenerative circuit 23 - 3 , passed electrically to the inductor 23 - 7 , having a flux linkage path to the inductor 23 - 2 below it, sent electronically to the regenerative circuit 23 - 8 , and passed further down the chain. [0179] A feedback continuous flux linkage path is illustrated with FIG. 23 b which shows an additional cell added to the top metal layer. The fourth cell has its regenerative circuits in the region 23 - 9 . Thus, 23 - 9 electrically drives the inductors 23 - 11 and 23 - 13 . The inductor 23 over inductor 23 - 10 driven by the regenerative circuit 23 - 8 , while the inductor 23 - 13 is over the inductor 23 - 12 driven by the regenerative circuit 23 - 4 . A feedback path would occur starting from the regenerative circuit 23 - 3 , sending the electronic signal to the inductor 23 - 6 , having a flux linkage path to the inductor 23 - 5 below it, sending the electronic signal to the regenerative circuit 23 - 4 , passed electrically to the inductor 23 - 12 , having a flux linkage path to the inductor 23 - 13 above it, sent electrically to the regenerative circuit 23 - 9 , passed electrically to inductor 23 - 11 , having a flux linkage path to the inductor 23 - 10 below it, sent electronically to the regenerative circuit 23 - 8 , passed electrically to the inductor 23 - 2 , having a flux linkage to the inductor 23 - 7 above it, and finally having the electrical signal ending at the regenerative circuit 23 - 3 . [0180] This is one of the benefits of this invention: the flux linkage between the cells have feedback and feed forward paths that lock the operation of the network to oscillate in a unified fashion. All of the paths converge to create a circuit that synchronizes the clock signal. [0181] FIG. 24 illustrates a MCM (Multi-Chip Module) 24 - 1 containing an inductor on each of the two die making up the MCM. The cross-sectional view has been simplified to provide the crux of the idea. For example, only one metal layer is shown on each die but those skilled in the art will appreciate that additional metal and dielectric layers can be added to the diagram without altering the idea. The lower die contains a substrate 24 - 2 and a dielectric layer 24 - 3 has been deposited on the substrate. A metal layer 24 - 5 with the shape of a coil (not shown) has been patterned on top of the dielectric layer 24 - 3 . The coil 24 - 5 has its first lead electrically connected to a via and a metal layer 24 - 6 . The second lead of the coil is electrically connected to the via and a metal layer 24 - 9 . The solder bumps 24 - 7 connect the lower die to the upper die. [0182] The upper die has a similar structure as the lower die to simplify the description and many of the numerals describing the features are the same. A dielectric layer 24 - 3 is deposited on the substrate 24 - 2 . A metal layer 24 - 8 with the shape of a coil (not shown) has been patterned on top of the dielectric layer 24 - 3 . The coil 24 - 8 has its first lead electrically connected to a first via and a metal layer 24 - 6 . The second lead of the coil is electrically connected to a second via and a metal layer 24 - 9 . The solder bumps 24 - 7 not only provide mechanical support to the two die but electrically connect the two coils in parallel as well. These two coils are now electrically connected in parallel and the flux of each coil is linked to the other coil due to their proximity to each other. [0183] So far, all of the flux linkage structures to distribute a clock signal over the surface of an IC were for one clock signal and its inverse. It is possible to create a flux linkage network that synchronizes a multi-phase signal. The intent would be to try to isolate each of the different clock phases from one another as much as possible and attempt to link up only the flux of the coils responsible for generating the same phase clock signals. The basic circuit, which will be distributed over the surface of the die, is illustrated in FIG. 25 a which was discussed earlier. This circuit 25 - 1 generates a set of balanced clock signals separated by 45°. Each block 25 - 2 , 25 - 8 , 25 - 9 and 25 - 10 generates a set of clocks. The top block 25 - 2 that generates φ1 has two inputs 25 - 3 and 25 - 4 and two outputs 25 - 5 and 25 - 8 . [0184] The circuit schematic within the top block 25 - 2 is illustrated in FIG. 25 b . The inputs 25 - 3 and 25 - 4 are applied to the gates of the two p-channel transistors, while the two outputs 25 - 5 and 25 - 6 are generated by the cross-coupled n-channel structure connected to the inductor 25 - 7 . [0185] The inductor 25 - 7 of the top block 25 - 2 is shown in its physical structure in FIG. 25 c responsible in part for generating the clock signal φ1. Each of the remaining blocks 25 - 8 , 25 - 9 and 25 - 10 contain an inductor 25 - 11 , 25 - 12 and 25 - 13 and is used to generate the clock signals φ2, φ3 and φ4, respectively, as indicated. The physical structure and the relative positioning of the three additional inductors with respect to each other is provided in FIG. 25 c as 25 - 17 . Note that the layout of each inductor contains an extension leg that is connected to the solid square 25 - 14 . This extension leg helps to segregate the flux within one inductor from each of the other inductors. The square 25 - 14 symbolically contains all the transistors within the circuit 25 - 1 with the exception of the inductors. Thus, this square 25 - 14 contains the transistors, capacitors, varactors, and electrical outputs. [0186] A single layout of the inductor with the extension leg 25 - 7 is indicated in FIG. 25 d . The extension leg has two leads and carries current 25 - 15 in both directions. If the leads are placed close together, Lenz's law will negate the value of the inductance of these two conductor trances; however, these trances will still add both parasitic capacitance and resistance into the circuit and needs to be accounted for during simulations. The square loop uses the measurements of d out and din for the loop as given earlier. Assume that the extension leg has a length of ½d out . [0187] The physical overlap flux linkage structure 25 - 16 of an inductor with a leg extension with another inductor with a leg extension is provided in FIG. 25 e . This type of layout will help to increase the flux linkage between the two coils, thus correspondingly increasing the coupling coefficient k. [0188] FIG. 25 f depicts the physical placement of two physical layouts 25 - 17 where the second one on the right is being rotated counter-clockwise by 180°. In addition, the physical representation of these layouts has been simplified where the detail of the inductor trace has been eliminated. After the rotation, the φ3 coil of the left layout 25 - 17 is placed over the φ3 coil of the right layout forming the physical overlap flux linkage structure 25 - 16 . This linkage improves as the two coils are aligned over one another along their edges. The entire physical structure 25 - 18 forms the basic building cell to generate a large array. [0189] The physical structure 25 - 18 is used to form the network 26 - 1 in FIG. 26 a . Note that to build this network, the physical structure 25 - 18 is duplicated and the odd phases are flux linked together horizontally while the even phases are flux linked together vertically. This layout is a 4×4 array having a size of 8d out by 8d out . Each basic cell generates the eight balanced outputs in each of their respective square 26 - 3 . In total, this layout 26 - 1 generates (4)*(4)*(8) or 128 outputs. The inductors along the periphery 26 - 2 need to be altered in value to account for the boundary condition. The inductor within these periphery locations are modified according to: L boundary =L internal (1+ k )  (8) [0190] The value in equation (8) uses the k coupling coefficient value for the physical overlap flux linkage structure 25 - 16 of the overlapping coils. [0191] The physical layout 26 - 1 was modeled and simulated in SPICE. FIG. 26 b illustrates a 200 psec window at time t=10 nsec where the simulated results of all 128 outputs in the array are shown. These outputs appear to be randomly distributed. However, the same 128 outputs waveforms are plotted in a 200 psec window at time t=100 nsec, revealing the results of FIG. 26 c . The flux linkage was given enough time to synchronize the network and generate the multi-phase signals that are separated 45° apart from one another. This is a fabulous result. This indicates that flux linkage can synchronize and distribute multi-phase signals over the surface of an IC. The measured spread of the skew at 100 nsec is 3 psec. [0192] FIG. 26 d provides a table 26 - 6 indication the simulation conditions when the circuit in FIG. 26 a representing the physical layout 26 - 1 was simulated in SPICE. The frequency of operation of the layout was targeted at 10 GHz and is an expected frequency of future VLSI and μprocessor chips. The process was a 0.13 μm CMOS technology having a core VDD of 1.2V. The transistor sizes in the regenerative circuit had a p-channel width of 20 μm and an n-channel width of 10 μm. Each basic cell generates 4 sets of balanced outputs and contains 4 regenerative circuits, one for each set of balanced outputs. The inductor was selected from the first row of the table given in FIG. 1 f . The inductance of each individual coil was 0.633 nH and had a parasitic resistance of 0.868Ω+0.24Ωfor the extension leg providing a total of 1.108Ω, where a sheet resistance of 0.01Ω/□ was used for the coils. The parasitic capacitance C OX of the coil and extension leg is 0.225 pF. The k coupling coefficient value was set at 0.9. [0193] FIG. 26 e gives a table 26 - 7 that uses the results of the current simulation of the physical layout 21 - 1 to determine expected parameters when the physical layout is increased in size to a die size of 1.6 cm×1.6 cm. The area of one of the sixteen cells in the physical layout is 500 μm×500 μm. The total area of the layout 26 - 1 in FIG. 26 a is 2,000 μm×2,000 μm, while the size of the μprocessor chip is 16,000 μm×16,000 μm. This data can be used to estimate the number of cells required in the μprocessor. In the layout 26 - 1 , 16 basic cells were placed together. A simple calculation indicates that the μprocessor would require 1024 cells to cover the surface of the 1.6 cm ×1.6 cm die. [0194] Each basic cell contains four regenerative circuits and as indicated earlier has a balanced output that drives a capacitive load consisting of parasitic and adjustable components. In this simulation, each output had an additional capacitive load of 0.5 pF connected to each output; part of which accounts for the inductor that have a capacitive load of 0.2225 pF. Thus, the total “drivable” capacitance (discussed earlier) in each cell is 4 pF and the total “drivable” capacitance of the layout 26 - 1 would be 64 pF. The corresponding capacitive value for the μprocessor is 4096 pF as indicated in the table. [0195] The power per cell was simulated to be 4 mW. Thus, the total power for the layout 26 - 1 is 64 mW while the μprocessor would dissipate about 4.1 W. The power dissipation for the μprocessor is similar to the previous case mentioned earlier where only one phase is distributed within the die. When the second stage buffers are added into the simulation, the power estimation increases to 7.6 W. This power is over an order of magnitude less than what is being predicted for these die. These simulations indicate that flux linkage is a very viable technique for present and future clocking networks of VLSI chips. [0196] Due to processing, voltage, and temperature (PVT) variations, a method of adjusting the frequency of the oscillators may be necessary. FIG. 27 illustrates a circuit description 27 - 1 that can be utilized to adjust the frequency of each individual oscillator. A coarse adjust signal is introduced at input 27 - 2 and applied to all coarse adjustment capacitors 27 - 3 . Note that the oscillators generate a balanced signal so that both outputs need to be adjusted. There is also non-adjustable capacitor 27 - 4 that models the transistor, inductor and interconnect wiring parasitic capacitances. The signal 27 - 2 can be a digital bus signal, analog, or a combination of both. After the coarse adjustment, each oscillator is probed for its frequency signal after being amplified by the buffer 27 - 7 . This buffer can be a diff-amp, inverter, or any high speed buffer. A finite state machine (FSM) 27 - 14 generates a bus signal 27 - 9 that enables the mux 27 - 8 and enables the register 27 - 16 . The buffer 27 - 7 passes the signal through the enabled mux to the output signal 27 - 10 . This signal is applied to the frequency detect circuit 27 - 12 which compares it against a reference oscillation signal 27 - 11 . The output of the frequency detect determines whether the frequency is too low, within range, or too high and generates a signal 27 - 13 . This signal is applied to the FSM 27 - 14 which then decides what to do. If the frequency is very far off, the FSM 27 - 14 may command a change in the coarse signal 27 - 2 , otherwise information is sent to the register 27 - 16 via the line 27 - 15 so that the register is set to a weight that will adjust the fine adjust capacitors 27 - 6 within the oscillator. If the frequency comparison in 27 - 12 is acceptable, the signal 27 - 13 instructs the FSM 27 - 14 to select the next oscillator using the signal 27 - 9 . This signal enables the next buffer to place its signal onto the lead 27 - 10 to be analyzed. In addition, the register 27 - 16 is disabled from being altered and the contents it holds remains fixed which maintains the correct fine adjust value for the capacitors 27 - 6 in the first oscillator. The next oscillator's register 27 - 18 , for example, is enabled to get ready to set its register to the unique fine adjust value. [0197] Another form of frequency adjustment is depicted in FIG. 28 a . This is a passive capacitance flux linkage frequency adjustment circuit 28 - 1 . An LC tank circuit contains a regenerative circuit, an inductor 28 - 4 and generates two outputs 28 - 6 and 28 - 5 . The inductor is mutually coupled via flux linkage to a second inductor 28 - 3 . This second inductor 28 - 3 forms part of a tank circuit where the capacitor 28 - 2 forms the other part. The capacitor 28 - 2 is adjustable and by adjusting its value the frequency of operation of the circuit 28 - 1 can be altered. [0198] The simulated waveforms for this circuit 28 - 1 are illustrated in FIG. 28 b . When the capacitance of the capacitor 28 - 2 is set to 1.7 pF, the waveform 28 - 8 is generated which is about 13.8 GHz. When the capacitance of the capacitor 28 - 2 is set to 1.0 pF, the waveform 28 - 7 is generated which is about 5.8 GHz. Thus, by varying the capacitance of a passive circuit that has a flux linkage to an LC tank circuit, the frequency of operation of the LC tank circuit can be altered. [0199] The use of a varactor 28 - 10 to adjust the frequency of a oscillator 28 - 7 is illustrated in FIG. 28 c . The oscillator outputs 28 - 8 and 28 - 9 are loaded with the capacitance of the varactor 28 - 10 controlled by the application of a DC voltage 28 - 11 . As the voltage 28 - 11 is changed, the capacitance of the varactor changes and adjusts the frequency of the oscillator. [0200] FIG. 28 d illustrates the use of a digitally controlled capacitor 28 - 13 and 28 - 14 to adjust the frequency of the oscillator 28 - 12 . As before, the capacitive loads 28 - 13 are applied to the outputs 28 - 7 and 28 - 8 of the oscillator 28 - 12 . The switches 28 - 14 control the amount of capacitance connected to the oscillator. As more capacitance is added, the frequency decreases. [0201] FIG. 28 e shows the use of an enhancement mode transistor 28 - 16 used as an adjustable capacitor applied to the oscillator 28 - 15 . The DC voltage 28 - 17 controls the adjustment of the amount of capacitance applied to the nodes 28 - 7 and 28 - 8 of the oscillator 28 - 15 . [0202] FIG. 28 f illustrates a depletion transistor 28 - 19 used as an adjustable capacitor being applied to the nodes 28 - 7 and 28 - 8 of the oscillator 28 - 18 . A DC voltage 28 - 20 makes the adjustment. [0203] Due to (PVT) variations, a method of adjusting the capacitance of the flux linkage frequency adjustment circuit may be necessary. FIG. 29 illustrates a circuit description 29 - 1 that can be utilized to adjust the frequency of each individual oscillator. A finite state machine (FSM) 29 - 14 generates a bus signal 29 - 9 that enables the mux 29 - 8 . The top oscillator sends its frequency signal after being amplified by the buffer 29 - 7 and passes the signal through the enabled mux to the output signal 29 - 10 . This buffer can be a diff-amp, inverter, or any high speed buffer. This signal 29 - 10 is applied to the frequency detect circuit 29 - 12 which compares it against a reference oscillation signal 29 - 11 . The output of the frequency detect determines whether the frequency is too low, within range, or too high and generates a signal 29 - 13 . This signal is applied to the FSM 29 - 14 , which then decides what to do. If the frequency is very far off, the FSM 29 - 14 may enable register 29 - 19 by the bus 29 - 9 . Then the FSM will issue a coarse adjust weight on bus 29 - 2 that sets the register 29 - 19 . This signal 29 - 2 can be digital signal or bus, analog, or a combination of both. The register 29 - 19 outputs a signal 29 - 21 to the coarse adjust capacitor 29 - 3 . Then the process of comparing the signal from the top oscillator against the reference oscillator 29 - 11 is performed in the frequency detect circuit 29 - 12 again. This time if the frequency comparison is off less than a coarse adjust change, the FSM 29 - 14 can decide to reduce the frequency slightly, keep the frequency the same or increase it slightly. Assume that the FSM decides to alter the frequency, a signal is issued on 29 - 9 to disable register 29 - 19 , holding the previously determined coarse adjust values, and to enable register 29 - 16 . Fine adjust information is sent to the register 29 - 16 via the line 29 - 15 . The register 29 - 16 issues the fine adjust on bus 29 - 17 which sets the weight that will adjust the fine adjust capacitors 29 - 6 within the top oscillator. There is also non-adjustable capacitor 29 - 4 that models the inductor and interconnect wiring parasitic capacitances. After the fine adjustment, if the frequency comparison in 29 - 12 is acceptable, the signal 29 - 13 instructs the FSM 29 - 14 to select the next oscillator using the signal 29 - 9 . This signal 29 - 9 alters the mux connection so that the next buffer in the next oscillator can place its signal onto the lead 29 - 10 to be analyzed. In addition, the register 29 - 16 is disabled from being altered and the contents it holds remains fixed which maintains the correct fine adjust value for the capacitors 29 - 6 in the first oscillator. The next oscillator's coarse adjust register 29 - 20 , for example, is enabled to get ready to set its register to the unique coarse adjust value. [0204] FIG. 30 a illustrates another method of adjusting the frequency of the LC tank circuit. This is a passive mechanical flux linkage frequency adjustment circuit 30 - 1 . An LC tank circuit contains a regenerative circuit, an inductor 30 - 4 and generates two outputs 30 - 6 and 30 - 5 . The inductor is mutually coupled via flux linkage to a second inductor 30 - 3 . This second inductor 30 - 3 forms part of a tank circuit where the capacitor 30 - 2 forms the other part. The flux linkage is adjustable by varying the position of the second coil 30 - 3 with respect to the first coil 30 - 4 . Thus, adjusting the k coupling coefficient can alter the frequency of operation of the adjustment circuit 30 - 1 . [0205] The simulated waveforms for this circuit 30 - 1 are illustrated in FIG. 30 b . When the k value is set to 0.1, the waveform 30 - 14 is generated which is about 13.6 GHz. When the k value is set to 0.9, the waveform 30 - 13 is generated which is about 8.8 GHz. Thus, by varying the position of an inductor that has a flux linkage to an LC tank circuit, the frequency of operation of the LC tank circuit can be altered. [0206] FIG. 30 c illustrates a MEMS (Micro Electro Mechanical System) 30 - 1 containing an inductor on each of the two die making up the MEMS. The cross-sectional view has been simplified to provide the crux of the idea. For example, only one metal layer is shown on each die but those skilled in the art will appreciate that additional metal and dielectric layers can be added to the diagram without altering the idea. The lower die contains a substrate 30 - 2 and a dielectric layer 30 - 3 has been deposited on the substrate. A metal layer 30 - 5 with the shape of a coil (not shown) has been patterned on top of the dielectric layer 30 - 3 . This inductor has its leads connected to the regenerative circuit (not shown). A dielectric layer 30 - 4 is deposited on the metal layer 30 - 5 . Two posts 30 - 6 are placed on the dielectric layer 30 - 4 . A second inductor is formed on the opposing substrate 30 - 12 . A dielectric layer 30 - 11 is deposited on the substrate 30 - 12 . A coil is patterned in the meal layer 30 - 10 . A dielectric layer 30 - 9 is deposited on the metal. Two posts 30 - 8 are placed on the dielectric layer 30 - 10 . The two sets of posts form a sliding surface which allows the top substrate to move vertically in and out of the page. This displacement causes the flux linkage between the two inductors to change. This change causes the frequency of the lower LC tank circuit to change that is the desired effect. [0207] FIG. 31 a depicts two instances of a representation of the physical layout 31 - 1 of the LC tank circuit given in FIG.22 b . This corresponds to a single regenerative circuit connected in parallel to four inductors. In addition, each of the inductors has an extension leg. This layout only generates only one balanced signal. The layout of the inductors insures that the current within the inductors flows in the same direction (clockwise, for example) within each inductor. Furthermore, note that the two layouts minimize the flux linkage between each other since there is a distance between the placement of these two layouts 31 - 1 . [0208] FIG. 31 b illustrates these two physical layouts in a cross section view of an IC. Not all the layers are shown; for example, the semi-conducting layers where the transistors are formed are not depicted. In addition, not all the metal, poly, and oxide layers are indicated. This simplification only presents the crux of the invention without explaining the full detail of the cross sectional view. The IC has a substrate 31 - 4 , and then an oxide layer 31 - 5 is deposited on the substrate. The metal conductors forming the inductors of 31 - 1 are deposited next as the layer 31 - 6 . Finally, an oxide layer 31 - 7 coats the metal layer. [0209] The top structure 31 - 9 is placed close to the surface of the IC. This structure 31 - 9 contains circuitry to generate RF signals. These signals can originate from individual inductors, cavity oscillators, antennas, or other forms of RF signal generation. These signals 31 - 8 are applied to the surface of the IC and are detected by the coils formed in the metallization 31 - 6 . These signals 31 - 8 are used to force each of the LC tank circuits into synchronism. Thus, the external signal provides the stimulus to synchronize individual non-interacting LC tank circuits 31 - 1 . That is, although the flux linkage between the layouts 31 - 1 is zero, the external stimulus 31 - 8 can be used to synchronize these independent cells. [0210] Finally, it is understood that the above description are only illustrative of the principle of the current invention. It is understood that the various embodiments of the invention, although different, are not mutually exclusive. In accordance with these principles, those skilled in the art may devise numerous modifications without departing from the spirit and scope of the invention. For example, the inductor in a flux linkage system can be portioned into a physical layout that may be, but not limited to, circular, hexagonal, or rectangular. In another example, the MOS transistors illustrated in the regenerative circuit can be replaced by BJT transistor to provide a negative impedance and maintain the oscillations.

CMOS LC tank circuits and flux linkage between inductors can be used to distribute and propagate clock signals over the surface of a VLSI chip or μprocessor. The tank circuit offers an adiabatic behavior that recycles the energy between the reactive elements and minimizes losses in a conventional sense. Flux linkage can be used to orchestrate a number of seemingly individual and distributed CMOS LC tank circuits to behave as one unit. Several frequency-adjusting techniques are presented which can be used in an distributed clock network environment which includes an array of oscillators. A passive flux linkage, mechanical, and finite state machine technique of frequency adjustment of oscillators are described.

FIELD OF THE INVENTION [0001] The invention relates to a medical system designed to deliver a fluid to a patient according to several modes of operation one of them being a safe mode. Said safe mode also allows the delivery or treatment to continue if a probable anomaly is detected. The present application claims the priority of the application bearing the number EP 14189455.0, filed on Oct. 17, 2014 in the name of Debiotech, the entire content of which is to be considered to form part of the present application. PRIOR ART [0002] The device now disclosed may be suited to numerous delivery devices. However, it is particularly well suited to treatments using peritoneal dialysis. [0003] Peritoneal dialysis is a therapeutic means of purifying the blood. It allows a patient suffering from renal insufficiency to eliminate impurities such as urea and excess water which would usually have been eliminated from their body by kidneys functioning normally. This therapeutic means makes use of the patient's peritoneum. The peritoneal membrane has a very large surface area and comprises a great many blood vessels. It thus acts as a natural filter between the blood and any liquid potentially present in the peritoneal cavity. Numerous patents disclose systems for performing peritoneal dialyses (EP 1 648 536 A2, EP 0 471 000 B1, EP 1 195 171 B1, EP 1 648 536 B1 which are incorporated by reference into the present description) for injecting and removing fluid into and from the patient's peritoneum. [0004] Treatment by peritoneal dialysis is relatively simple and comprises at least one cycle of three distinct phases: the “fill”: the system injects dialysate into the patient's peritoneal cavity (this is also referred to as the injection phase); the “dwell”: the system leaves the dialysate in the peritoneal cavity for a determined length of time (also referred to as the stasis phase); the “drain”: the system removes the dialysate present in the peritoneal cavity (this is also referred to as the drainage phase). [0008] In the present document, a phase may be a fill, a dwell or a drain (it being possible for each phase to be complete or partial), a cycle comprises a fill, a dwell and a drain, and the treatment may comprise several cycles. In other words, the phases may be repeated during one and the same treatment. [0009] Systems generally referred to as APD (automated peritoneal dialysis) systems are designed to perform several fill, dwell and drain phases succeeding one another, in other words several cycles succeeding one another during one and the same treatment. This type of system thus performs a treatment over a number of hours. APD systems are also particularly suitable for use over night and/or at the patient's home. [0010] Such systems comprise means designed to check and/or monitor their correct operation. These means may measure or estimate or calculate the volumes injected into or removed from the peritoneum. For example, these means may comprise a sensor connected to a processor. Checking these volumes is of primordial importance. Specifically, under no circumstances must the system inject too great a quantity of dialysate into the peritoneal cavity nor leave a significant volume at the end of the treatment or at the end of each drain phase. That could have several impacts on the patient's health (damage the peritoneum, cause pulmonary edema, loss of ultrafiltration capability, respiratory insufficiency or cardiac insufficiency, etc.) or, at the very least, make the patient rather more uncomfortable even if it does not have vital consequences. [0011] If a sensor is defective and the system fails to detect this defectiveness, the sensor may cause an overestimate or underestimate of the volumes injected and/or removed during the treatment. This error is all the more significant when the treatment comprises several cycles because, in that case, the estimation error is repeated on each cycle and becomes cumulative. This error may be the result of one or more factors, such as wear or a defect (temporary or otherwise) of the machine, of the pumping system, of the sensors, movement on the part of the patient, a change in temperature, etc. If the system comprises a disposable part (tube, cassette, reservoir, etc.) and a reusable part (machine, electronics, sensor), it may also be the result of a poor connection/coupling between the two parts. [0012] In an anomaly, the systems of the prior art simply alert the patient or the medical personnel so that one or more actions can be taken to correct the problem. Certain very far-sighted systems even prefer to alert the user even when a potential anomaly is detected. [0013] If the treatment is being performed overnight and/or in the patient's own home, certain alarms may disturb the patient's sleep without this being truly necessary and/or may needlessly alert the patient when the latter does not have the capability of intervening. In addition, the true cause of the triggering of the alarm may sometimes be the fact that the patient has simply moved during treatment. Thus, it would be needless to awaken the patient like systems of the prior art do, because the fault would be only temporary and would not truly endanger the safety of the patient. [0014] In other circumstances, the anomaly may persist or at least doubt as to the anomaly may lead the system of the prior art to shut down the system prematurely, leading to an interruption to treatment that the patient needs. In general, the systems of the prior art favor interrupting the treatment as soon as there is a malfunction that could carry a risk to the patient. In particular, no system of the prior art foresees modifying the treatment in order to limit this patient risk while at the same time continuing to operate in the presence of such a malfunction. GENERAL DESCRIPTION OF THE INVENTION [0015] The invention presented in this document introduces greater intelligence into the processing of the data and/or operation of the system so as to optimize the treatment even in the event of an anomaly or in the event of a potential anomaly being detected. In particular, the invention can switch mode of operation (namely for example modify one or more parameters of the treatment) after detecting a possible anomaly and this new mode of operation may be called “safe” because it is potentially less effective than the original mode but allows the patient to be provided with a treatment which is still more favorable then prematurely shutting down the treatment while nevertheless guaranteeing the safety of the patient. The principle of the invention is a system designed to guarantee a minimum treatment (the most favorable to the patient in the given circumstances, for example according to the level of awareness of the status of the system and/or of the surroundings of the patient) while at the same time providing an effect that is favorable to the patient's health. [0016] In other words, the system invented makes it possible to carry out a treatment that is less effective when it detects a defect, which meets less tight specifications (for example duration of treatment, fluid flow rate, etc.) than a system that does not have a defect but which nevertheless guarantees the safety of the patient and the continuity of his/her treatment. Thus, unlike the systems of the prior art, if one or more defects or faults are detected, or suspected, rather than halting the treatment and going into alarm mode (and thus disturbing the patient and giving him or her only an incomplete treatment that is insufficient and potentially harmful), the system invented will adjust the treatment (some or all of the parameters that describe same) to guarantee that the treatment is continued to its end, that the required precision for patient safety is maintained, but without guaranteeing that the specifications of the machines are adhered to. [0017] The system presented in the document is particularly suited to peritoneal dialysis systems and even more particularly suited to automated peritoneal dialysis (APD) systems, because of the repeating of the cycles. Specifically, the addition of a repetitive cycle may have a very strong impact on the imprecision of a device if the latter is faulty, leading to a systematic fault risk. On each cycle, this fault will combine with the fault of the preceding cycle to give rise, after several cycles, to an effect that is highly significant. [0018] A first aspect of the invention relates to a medical device which comprises at least two modes of operation. A first mode of operation referred to as normal in which the system defines a collection of parameters (for example a volume, a delivery rate, a number of cycles, etc.) in order to achieve the desired effect using a certain therapeutic prescription. A second mode of operation referred to as “safe” in which the system has detected a failure or an anomaly or a disrupting event which forces the system to modify at least one of said parameters in order to continue the treatment with a new collection of parameters (for example to decrease or increase the volume, the delivery rate and/or the cycles, etc.). Said mode of safe operation may potentially not reach the same level of effectiveness (which can be measured for example through the quantity of ultrafiltrate, the duration of the treatment, etc.) as the mode of normal operation. However, this mode of operation makes it possible to achieve a minimum treatment effectiveness, which is notably more favorable than interrupting the treatment, while at the same time guaranteeing patient safety. [0019] According to a second aspect of the invention, the device comprises a mode of safe operation, as described previously, but the parameters of which may be adapted according to the significance of the anomaly and/or the way in which it is evolving. In other words, the safe mode is less effective than the normal mode, this mode making it possible to guarantee patients safety while at the same time adapting the parameters so as to provide the patient with treatment that is optimal according to the actual circumstances. For example, it may be that a drift in a sensor has been detected and that as the data from the sensor gradually drift, the device adapts the parameters such as a progressive lowering in the delivery rate or volume of fluid injected or an increase in the volume drained. Depending on the measurements taken by the various sensors, and if the doubt as to the presence of a fault increases or the estimate of the risk of the impact this fault will have on the quality of the treatment or on the risk that the patient is running increases, the mode of safe operation will adapt the treatment parameters each time leading to a lowering of the effectiveness of the treatment but guaranteeing that the new treatment will remain safe for the patient. [0020] In one embodiment, the system comprises at least one sensor (pressure sensor, temperature sensor, delivery rate sensor, etc.) connected to a processor intended to define the status of the system or to monitor a parameter of the treatment or of the environment of the system. The processor may be designed to recognize a failure of this sensor or to assume a failure with this sensor. This can be done either by duplicating the sensors and comparing the values given by the two entities. A difference means that one of the elements at least is faulty. It may also be done by comparing the response of the sensor against an ideal theoretical curve. In the event of a difference that is too pronounced, the sensor will be considered to be faulty. If the fault with this sensor can be neglected, the system may decide to continue with the treatment in a mode of normal operation. If the fault with this sensor leads to consequences that may potentially jeopardize patient safety, then the system has the capability of defining a new collection of parameters according to a mode of safe operation capable of continuing the treatment and guaranteeing patient safety even in the presence of the detected or suspected anomaly. [0021] During treatment, the anomaly may evolve, for example intensify, and the system is then (once again) designed to redefine a new collection of parameters accordingly that will make it possible to guarantee patient safety to the end of the treatment, even if this treatment loses in effectiveness. For example, if a sensor used for calculating, measuring or estimating the volumes injected or drained becomes defective, the system may decrease the quantity injected or increase the quantity drained in order to limit the risks of overfilling the patient that could be the result of such a failure of this sensor. On each cycle and during the various phases, the system may gradually modify one or more parameters: volume displaced, pump delivery rate, temperature, etc. [0022] In one embodiment, the system comprises two sensors ensuring redundancy of the measurement of a parameter ensuring patient safety. These sensors may for example measure (or calculate using the processor) the delivery rate so as to be sure of the precision of the delivery rate of dialysate injected or drained. In the event of a fault with at least one of the two sensors, the safe mode will preferably be activated, thereby ensuring patient safety on the basis of just one functional sensor. The failure of one of the two sensors may be detected from the fact that the discrepancy between the two sensors exceeds a certain threshold or that the pressure profiles are not consistent with one another or with the operation of the pump. [0023] In the foregoing paragraphs the failure described is that of a sensor. It is obvious to a person skilled in the art that it could be any kind of system failure. Such a failure may affect a sensor but may equally affect any other part of the system and be identified by a sensor present in the system. [0024] According to a third aspect of the invention, the device has the ability to decide to maintain treatment (in normal or safe mode) under conditions that are optimum for patient safety or to stop the treatment prematurely depending on the anticipated effectiveness of each of these options (continuing the mode of normal operation, switching to a mode of safe operation, prematurely stopping the treatment). In other words, the system comprises a processor designed to evaluate the potential effect of the alternative treatment or treatments and compare the effect on the health of the patient with the effect of prematurely stopping the treatment. Thus, the system is capable without intervention from the patient or the care personnel, of deciding on the best option for the patient's health and safety under all circumstances. In particular, it may be considered that if the fault is detected at an advanced stage in the treatment, for example when a certain predefined percentage of the treatment has been carried out, it is preferable to stop the treatment rather than continuing under conditions of lower effectiveness. [0025] A fourth aspect of the invention relates to a method of controlling a peritoneal dialysis apparatus comprising the following steps: observing at least one parameter relating to the treatment determining a first acceptable range of values for said parameter switching from one mode of operation to a first mode of safe operation if the data of said at least one parameter are outside said first acceptable range of values. [0029] The method may involve progressively adapting the acceptable range of values and the mode of safe operation suited to this range of values for said parameter. LIST OF FIGURES [0030] The invention will be better understood hereinafter by means of a number of illustrated examples. [0031] It goes without saying that the invention is not restricted to these embodiments. [0032] FIG. 1 illustrate the coupling between a cassette and a cycler. [0033] FIG. 2 illustrates various possible modes of operation. [0034] FIGS. 3 to 7 schematically illustrate the possible operation of such a device. [0035] FIG. 8 briefly illustrates a minimum embodiment. [0036] FIGS. 9 to 11 b schematically illustrate the possible operation of such a device. NUMERICAL REFERENCES USED IN THE FIGURES [0000] 1 Cycler 2 Cassette 3 Fluid inlet or outlet 4 Actuator (valve) 5 Pressure sensor 6 Region of coupling of the cassette to a pressure sensor 7 Pumping mechanism 8 Actuator (of the pumping mechanism) 9 Valve 10 Sensor 11 Processor 12 Possible mode of operation 20 Parameterizing 21 Pump activation 22 First condition met? 23 Switching the mode of operation 24 Previous parameters unchanged 25 Second condition met? 26 Stop the pump 30 Pumping system 31 Pressure sensor 1 32 Pressure sensor 2 33 Direction of flow of the fluid propelled by the pump 34 Processor DETAILED DESCRIPTION OF THE INVENTION [0061] In the present document, the detailed description of the invention includes embodiments of devices, systems and methods which are given by way of illustration. Of course, other modes of embodiment are conceivable and may be applied without departing from the scope or spirit of the invention. The detailed description that follows must therefore not be considered to be limiting. [0062] Unless indicated otherwise, the scientific and technical terms used in the present document have the meanings commonly employed by those skilled in the art. The definitions given in this document are mentioned with a view to making the frequently used terms easier to understand and are not intended to restrict the scope of the invention. [0063] The direction indications used in the description and the claims such as “top”, “bottom”, “left”, “right”, “upper”, “lower” and other directions or orientations are mentioned in order to provide greater clarity with reference to the figures. These indications are not intended to limit the scope of the invention. [0064] Verbs “to have”, “to comprise”, “to include” or equivalent are used in this document in a broad sense and in general terms signify “include, but not limited to”. [0065] The term “or” is generally employed in a broad sense encompassing “and/or” unless the context clearly indicates the opposite. [0066] The term “treatment” is to be understood as meaning the action or series of actions aimed at achieving one or more therapeutic objectives during a defined period of time. Here, a treatment begins from the moment the patient switches the system on (and/or couples the fluidic connections) and continues until the patient switches this system off (and/or disconnects the fluidic connections). The system defines a collection of parameters (pump speed, pressure, actuation, temperature, pressure monitoring, liquid volumes displaced, starting and stopping of phases, etc.) for performing a treatment. A treatment is said to be normal if the collection of parameters makes it possible substantially to achieve the predefined therapeutic objectives. The duration of the treatment is qualified as normal if this duration is substantially close to the normal treatment duration. In other words, the term “normal” here qualifies the operation/progress of the treatment. [0067] The term “effectiveness” is to be understood as qualifying an effect, in this instance a treatment. Also, the term “effective” may be defined as follows: “something that produces the expected effect”. In other words, a treatment that is effective needs to be understood to mean a treatment defined by a prescription and which has produced the desired effect (for example quantity of ultrafiltrate obtained at the end of the treatment). Thus, the term “effectiveness” here qualifies the result of the treatment. There is an idea of relativity that comes out of the term “effectiveness”. Specifically, a treatment may be more or less effective. This effectiveness may vary considerably from one treatment to another and is dependent on numerous variables. In the present document, the effectiveness between normal treatment and the treatment actually carried out is compared. [0068] The expression “mode of safe operation” is to be understood to mean a mode of operation of the system that does not necessarily make it possible to achieve the predefined objectives or the desired effectiveness of treatment referred to as normal. In other words, the mode of operation referred to as normal operation should in theory be more effective than a mode of safe operation. In the field of medicine, this mode of safe operation must also meet patient safety requirements. Concept and Methods of Operation: [0069] According to the embodiment of FIG. 2 , the system comprises a checking device employing at least one element of the system such as an electronic processor ( 11 ) and a sensor ( 10 ). The system is designed to determine or select a collection of parameters (volume injected, drained, heating of the fluid, pressure, delivery rate of the pump, duration, number of cycles and phases, etc.) that can be predefined by the care personnel. Using this checking device, the system is designed to define or select at least the following modes: a mode of normal operation and a mode of safe operation. A mode of safe operation may be a mode of minimal operation. There may also be several intermediate modes of safe operation. These modes are characterized by their lower effectiveness as compared with the normal mode while remaining more effective than the minimal safe mode. [0070] A memory connected to the processor may be used to record the various modes of operation and the system is designed by virtue of the checking device to select one of these modes of operation. A doctor may preparameterize one or more different modes of operation according to different possible scenarios (defective sensor, etc.). A decision tree may be used by the checking device to choose the appropriate mode of operation. The selection may also be performed in cascade where the checking device moves on from one mode of operation to another until a mode of operation compatible with the conditions known to the system is obtained. [0071] In one embodiment, the system is designed to operate as disclosed in FIG. 3 . At the start of treatment, the system defines parameters ( 20 ) according to the prescription defined or programmed or given by the care personnel. This first mode of operation will be termed normal. The system starts the pump and, thanks to the sensors, the system verifies or monitors a collection of data. If a first collection of conditions ( 22 ) is not met then the system can switch to a mode of safe operation (which may be the minimal mode) guaranteeing patient safety and continuing the treatment even though a condition is not met (for example a sensor is faulty). The treatment will then undoubtedly be less effective but will remain safe and the patient will nevertheless have received some treatment. This is a mode of safe operation. If the first condition is met then the treatment can continue (or begin) with the parameters defined previously. A collection of conditions may include one or more conditions (not crossing a threshold and/or exiting a range of operation and/or range of measurements and/or a data mean and/or a step correctly completed, etc.). The various modes of operation may be characterized by a collection of predefined parameters and the system moves on from one mode of operation to another as soon as one or more operating conditions are not met (a threshold is crossed, a prescribed quantity of fluid is not completely used, a sensor is defective, sensor data are incoherent, there is too great a measurement discrepancy between the various sensors, etc.). [0072] The system may be designed to monitor this first collection of conditions right from the start of treatment and/or during the course of treatment (periodically or otherwise). For example, at each start of phase and/or at regular or random time intervals. A second collection of conditions may be verified right at the start of the treatment and/or during the treatment (periodically or otherwise). If this second collection of conditions ( 24 ) is met then the system may be designed to: periodically reverify the first collection of conditions (option 1), and/or maintain the previously defined mode of operation (option 2). [0075] The system may carry out the check on the various conditions sequentially or in parallel. Such verifications may be performed just once or throughout the treatment at regular or variable time intervals. [0076] When the second condition is not met, the system may decide: to stop the treatment, or to redefine ( 20 ) a new collection of parameters so as to continue the treatment in a mode of safe operation which nevertheless remains less effective (for example longer because the new parameterizing defines a slower delivery rate) than the mode of normal operation but more effective than the mode of minimal operation. Before redefining this new collection of parameters, the system may temporarily stop the pump. [0079] In one embodiment, the system is designed to operate as divulged in FIG. 4 . The system at the start of treatment parameterizes a mode of normal operation and the process is performed for the most part as in FIG. 3 . As long as the second collection of conditions is met, the system will continue to operate according to the mode of normal operation. If the second collection of conditions is not met, the system will also verify the first collection of conditions. If the first collection of conditions is not met then the system will switch to a mode of minimal operation. If the first collection of conditions is still met then the system will modify one or more parameters and will switch to a mode of safe operation so that the second collection of conditions is met. The second collection of conditions may be adapted according to predefined parameters. Namely, the second collection of conditions may still be identical even in the event of a change of mode of operation, or it may be modified. In the latter instance, one or more conditions may be less restrictive (for example: broadened range: threshold extended, acceptance of a step not correctly completed, etc.). As long as the second collection of conditions is met the system may maintain the parameters defined previously (whether that be in the normal or the safe mode). The system may also be designed to revert to a mode of normal operation after a certain length of time or according to certain conditions. The system will perform a loop check on the conditions and will adjust the mode of operation to best suit, according to the data it receives. [0080] In one embodiment, the system is designed to operate as disclosed in FIG. 5 . The system at the start of treatment parameterizes a mode of normal operation and the process takes place in part as in FIGS. 3 and 4 . The system verifies a second collection of conditions and optionally a third collection of conditions (at the same time or sequentially or in the event of a change of mode of operation). [0081] In one embodiment, the system is designed to operate as disclosed in FIG. 6 . The system at the start of treatment parameterizes a mode of normal operation and the process takes place in part as in FIGS. 3, 4 and 5 . In this system, the third collection of conditions is monitored, insofar as the second collection of conditions is met. However, as long as the third collection of conditions is not met, the treatment continues according to the previous mode of operation. And when the third collection of conditions is met, then the treatment is stopped. Here, the third condition may be the volume injected, the programmed number of cycles, the duration of the treatment. [0082] In an embodiment disclosed through FIG. 9 , the system comprises a certain number of predefined safe modes of which one is a minimal mode. By predefinition, it may be appreciated that the system already has a certain number of safe modes one of them being a minimal mode in which the parameters are all defined at least before the start of the treatment. A strategy may be defined for determining (using algorithms, a fuzzy-logic approach, or an approach of the artificial intelligence type for example) the new parameters of the safe treatment according to the parameters of the normal treatment and the circumstances encountered. These various parameters will tend towards the series of parameters defining the minimal safe mode. During the course of treatment, the system regularly performs various tests and observes the way in which the various elements of which it is made up behave. These tests may be performed during the treatment or may require a temporary stoppage of the treatment. For preference, these tests are performed by the processor of the system and use data relating to the operation of the system (pressure, temperature, delivery rate, component status, etc.) and/or of the progress of the treatment (start/end of cycle, of phase, remaining quantity of fresh dialysate, quantity removed, UF, etc.). If, during the course of one of these tests or observations, the system notices or suspects a failure or a condition that has not been met, it may decide to implement the mode of safe operation. The mode of safe operation chosen will be dependent on the analysis made by the system of the actual or supposed fault. Once in this safe mode, the system will continue the treatment and the tests and checks. It may be that the switch to a first safe mode renders these tests and checks normal. It is also possible that these tests and checks will remain abnormal but that in such a safe mode the continuation of the treatment will be safe for the patient. If, over the course of time, the results of the tests and checks become poor again or deteriorate excessively, the system may decide to switch to a second mode of safe operation, less effective than the previous modes, but once again safe for the patient. This process may be repeated several times until the minimal safe mode is reached. [0083] In one embodiment, the system may follow a strategy in which each mode of operation is tested in order to obtain satisfactory test results (normal→A→B→C→. . . →Z). In another embodiment, one mode of safe operation may be favored according to the results of the previous test or tests (normal→A→D→B). Although in these examples mention is made of several modes of safe operation which succeed one another, the system may simply pass on from a mode of normal operation to a suitable mode of safe operation (normal→C). The system may also be designed to revert to a mode of normal operation (B→normal). [0084] At any time, the system may decide to stop the therapy if it considers that the therapy is sufficiently well advanced (according to a series of criteria defined in advance) or if it considers that even the minimal safe mode is unable to guarantee patient safety. [0085] In one embodiment, the system is designed to operate as disclosed in FIGS. 10, 11 a and 11 b , reusing the concepts set out hereinabove. Embodiments and Examples of Use [0086] For a better understanding of the operation, the description considers the example of a dialysis system as disclosed in FIG. 1 . The dialysis system comprises a cycler ( 1 ) (here depicted without its housing), and a cassette ( 2 ). The cassette is a disposable element whereas the cycler is used several times with different cassettes. The cassette ( 2 ) comprises a pumping mechanism ( 7 ) which may be a peristaltic or some other type (pneumatic, etc.) of pump, fluid inlets and outlets ( 3 ), valves ( 9 ), regions for coupling with a sensor ( 5 ) of the cycler ( 1 ). The inlets and outlets ( 3 ) may be designed to be connected via a tube (not depicted) to: a dialysate reservoir (not depicted), a patient (not depicted), a heating system (not depicted) and/or a fill and/or drain system (not depicted). The cycler ( 1 ) comprises a processor (not depicted in FIG. 1 ), sensors ( 5 ), actuators ( 4 , 8 ) designed to collaborate with the valves ( 9 ), the pumping mechanism ( 7 ) of the cassette. The cassette and the cycler are designed for perfect coupling of the sensors and actuators with the elements of the cassette. The cycler may also contain other sensors such as temperature sensors for measuring the temperature of the fluid or the ambient temperature, etc. If, for example, a sensor is defective or the cassette is defective or an element is present between the sensor and the cassette or between the cycler and the cassette, it may happen that the coupling between cassette and sensor is imperfect, giving rise to a drift in the data or giving rise to data that are completely erroneous. The membrane covering the flexible zone ( 6 ) may also be defective (noncompliant surface finish, deformation, etc.). [0087] As in any fluid delivery system, the volume of fluid delivered or drained is an essential data item that needs to be controlled. In the prior art, mention is notably made of the danger of overfilling dialysate in the patient's peritoneum. It is thus essential to have control over this data, which is the result of the volume delivered and/or drained. According to the type of device, it may be crucial to check the absolute value of the volume of fluid delivered and of the volume drained, or simply to ensure a good control of the balance, namely good control over the difference between the volume delivered and the volume drained. These volumes may be estimated using the pump itself (piston pump, peristaltic pump, etc.) and/or using sensors arranged or not arranged on the fluid line. Now, this estimate may be dependent on a certain number of physical causes such as the state of wear of the pumping system, the pressure at the inlet and/or at the outlet of the pump, the temperature, the programmed fluidic path, etc. This makes accurately estimating these volumes difficult. [0088] During a prior study, the effects of at least one of these parameters on the volume pumped is established by physical theory and/or numerical modeling and/or through characterization testing. This characterization testing may be carried out according to a test plan that is optimized to reduce the number of tests needed while at the same time covering the necessary range with sufficient precision. Such plans may be built on the basis of the “design of experiment” technique, using known methods (for example the Taguchi method) which may or may not include interaction between these causes. The physical values (for example the pressure of the fluid at the inlet of the pump) are themselves measured in the device by sensors. By measuring these physical values and with the corresponding effects previously established, the volume delivered by the pumping system can be corrected to improve its precision as disclosed in FIG. 7 . [0089] In general, each device comprises a determined number of sensors (often for cost and maintenance reasons). The system needs to operate with this limited number of sensors which means that the system has to operate with imperfect awareness of the environment and of certain factors. For example, the relative position of the patient and of the cycler is an important piece of information that will have an impact on the pressures of the fluid displaced in the cassette. In theory, the patient ought not to move during the treatment and the devices are not provided with sensors that are sufficiently precise to determine whether or not the patient moves during treatment. Now, if the patient changes position, for example if he rises by 20 cm with respect to the cycler, this will have a significant impact on the fluid pressure measurements and potentially also on the estimate of the displaced volumes. In other words, if the patient moves the cycler may detect that a variation in pressure has occurred, but does not necessarily know the cause for this (the origin of such a change in pressure may in actual fact have other causes such as, for example, the appearance of a restriction in the fluidic path. The cycler at best will notice this change but will have no means of discerning its origin). Thus, the cycler needs to operate to the best of its ability according to the given circumstances, according to the level of awareness of the status of the system and/or of the patient's environment. Thus, the system may have difficulty in assessing whether the observed change in the measurement is the result of a defect associated with the sensor or a movement of the patient. [0090] For measurement reliability purposes it is common practice to have at least a level of redundancy in sensors (for example two independent sensors are used to measure the pressure at the inlet to the pumping device). These two sensors are regularly compared in order to detect any potential error with one of the sensors, originating for example from a drift in the measurement or degradation of the interface between the sensor and the environment that is to be measured. According to the prior art, as soon as one of the sensors is deemed to be defective, the system goes into alarm mode and the treatment is interrupted. The object of the invention in such a situation is to continue the treatment in a mode referred to as safe mode. [0091] For greater clarity, the document sets out a system in which the means for calculating the volumes comprise a pressure sensor. However, these means may be other elements such as a volumetric chamber or a syringe plunger used for measuring volumes. [0092] According to one embodiment set out in FIG. 8 , the peritoneal dialysis device has two pressure sensors ( 31 , 32 ) intended to measure the pressure at the inlet of a pumping system ( 30 ) (for example a peristaltic pump). According to the pressure measured, the system adapts the delivery rate of the pumping system ( 30 ) in order to take account of the variations in delivery rate as a function of said inlet pressure. The processor ( 34 ) analyzes the data measured by the pressure sensors ( 31 , 32 ), estimates, as a function of at least these data, the quantity of fluid displaced by the pump. The processor is designed to adjust the operation of the pump (speed, rotational speed in the case of a peristaltic pump, delivery rate, operating time, etc.) accordingly in order to keep an effective delivery rate corresponding to the prescription. [0093] In the event of a suspected failure of one of the pressure sensors, the system switches to safe mode. This mode of operation may reduce the volume of at least one fill phase in order to limit the filling of the peritoneal cavity by a percentage that corresponds, for example, to the possible maximum positive deviation of pumping or to a maximum tolerated deviation beyond which there could be a risk to the patient. By making this correction, the system ensures that the peritoneum is not overfilled (such overfilling for example representing a cardiovascular risk to the patient), even assuming that the sensor remaining operational should fail. [0094] By way of example, in the event of failure of one of the two sensors (or assuming that one or both sensors is potentially defective), each filling of the peritoneal cavity in the next cycle will be reduced by 3% of the programmed volume. This percentage may be predefined according to the patient and/or according to the design of the system (the capacity of the pump, etc.). This percentage for example represents the risk of overfilling associated with this failure or the maximum excessive overfilling that could carry a risk to the patient. In this example, this may be a failure that is assumed because the discrepancy in measurement between the two sensors has crossed a certain threshold, leading to the assumption that at least one of the two sensors is defective or incorrectly coupled with the measurement zone (for example the membrane of the cassette). [0095] During multiple fillings, this percentage may be adapted to take account of the cumulative effect of overfilling on each cycle (for example 8 cycles at 3% represents a maximum risk of 24% of overfill). Of course the percentage may be adapted to take account also of the lesser drainage due to the same fault on each cycle. Which may represent, for example 24%, for 8 filling cycles, which combine with the 24% of lower drainage giving a total of 48% overfill over 8 cycles, which is close to the tolerated limit. [0096] These percentages may naturally differ greatly according to the filling and/or drainage conditions and the system will ideally best define the conditions for reducing the filling and/or increasing the drainage (in the case of partial drainage) in order to limit of risk of exceeding a 50% overfill (namely 150% of the peritoneal volume which is generally considered to be the acceptable limit). It is commonly conceded that 160% must under no circumstances be exceeded and that 180% carries a serious risk to the health of the patient. If the cumulative effect of various cycles carries a risk of causing these safety limits to be exceeded, it may be desirable during the treatment to carry out a full drainage cycle even though in the mode of normal operation the drainage of this cycle would not have been a complete drainage. Thus, by virtue of this complete drainage, the system ensures that the peritoneal cavity is drained almost completely and can therefore begin to cumulate the errors again from an empty belly. Thus, the system may carry out at least one complete drainage at fixed or variable cycle intervals or at intervals that may be dependent on the possible error percentage. This number may be set, for example, at 6 or 8 consecutive cycles. [0097] As soon as a sensor detects an abnormal variation in the pressure, even though the system cannot truly know the cause of this, the processor may decide to modify the mode of operation in order to adapt to this variation. For example, before beginning the treatment, the system defines certain parameters such as the volume delivered, the delivery rate and/or the phases of exchange. The system will then operate in a mode of normal operation. If the pressures measured at the inlet of the pumping system lie within an acceptable pressure range, the mode of normal operation will be used throughout the treatment. However, if at some moment in the treatment the measurements drift suddenly or progressively, and then cross a certain threshold, then the system may switch to another mode of safe operation in order to adapt to these measurements. The system will define at least one new collection of parameters, for example a reduction in the delivery rate (because the pressure sensors have detected an increase in pressure, which could be due to the patient rising relative to the cycler). This mode of operation may be considered to be a mode of safe operation because it will potentially be less effective than the mode of normal operation. Here, the treatment will be slower because of the drop in flow rate. If the drift continues and crosses another threshold then the system may once again redefine a collection of new parameters. [0098] In reality, the system does not know whether the patient has actually moved. This variation in pressure may be down to a number of causes. However, if this variation is due to the fact that the patient has, for example, risen by 20 cm, then the delivery rate needs to be lowered in order to avoid overfilling the patient's peritoneal cavity. It is for this reason that the system redefines these parameters even though the other systems of the prior art would have stopped the operation of the system. Each time the parameters are redefined, the system may also redefine the thresholds. [0099] According to another embodiment, the safe mode takes account of possible errors in measuring the temperature of the fluid and, therefore, possible errors in the filling and/or drainage volume. [0100] When the system is caused to switch to a mode of safe operation during a single treatment, the system may estimate that the cause of the problem was only temporary. In that case, the system may comprise a screen or an indicating means (colored LED, noise, etc.) to inform the patient that a problem has been detected during treatment. A memory may log these data so that the patient can transmit them to his or her doctor or with a view to logging machine errors. Ideally, the system will inform the patient that his or her treatment has been modified while in progress and that a certain percentage of the expected treatment will at least have been attained (for example 80%, which may quantify the therapeutic minimum obtained and cause the next treatments on subsequent days to be adapted, possibly accordingly). [0101] If the problem should recur, which means to say occur repeatedly in different treatments, then the system may be designed to encourage the patient to intervene or request an intervention or the system may itself request intervention from the maintenance center. The screen may advise the patient to perform certain operations or invite him or her to contact the maintenance department. [0102] As an example of operation of an embodiment allowing several adaptations, the pressure value measured at the pump inlet reaches a limit either because the patient has moved (with a sensor that is operational) or because the pressure sensor is drifting. In the latter instance, the sensor is defective and there is a risk of overfilling. To avoid overfilling, the delivery rate is reduced (which decreases the pressure at the inlet of the pump and therefore the risk of overfilling). This adaptation of the delivery rate corresponds to adaptation No. 1. With this new delivery rate, a new safety limit for the pressure measurement is calculated. If this new limit is reached, the delivery rate is reduced again, which corresponds to adaptation No. 2. The delivery rate can thus be reduced in succession n times (n adaptations) down to a delivery rate that no longer represents any risk (for example because the risk of overfilling is reduced below the safe limit of 120 to 150%). The consequence of this change in delivery rate will have an impact on the result of the treatment. Specifically, if the treatment is to be given over a determined length of time then all or part of the final cycle will not be able to be performed. In an extreme case, there may be a number of cycles that cannot be performed in order to comply with the predefined treatment duration. Thus, the result of the treatment will not be of such good quality as/will be less effective than the desired result. Thus, not all of the objectives of the treatment will be met. In other words, only some of the objectives will be met, in this instance at least the duration of the treatment. In another embodiment, it is the stasis duration that may be favored. Thus, the duration of stasis will be unchanged because it is predefined, but the total duration of the treatment will instead increase. The prescriber may determine in advantage which objectives cannot be modified or which are to be prioritized in the event of a problem. Thus, he or she may predefine the parameters that cannot be changed by the processor when switching to a mode of safe operation. [0103] In instances in which the system comprises two redundant sensors, the method or methods described hereinabove are particularly suitable when one or both sensors are defective or when the cassettes is incorrectly installed in the cycler or when the pressure sensor or sensors are incorrectly coupled to the cassette. [0104] Example of operation of an embodiment allowing complete drainage, a fault is detected which, in the worst case scenario, represents a risk of overdosing of the pumping device by 6%. Thus, in theory, on each cycle, 6% of volume is added to the volume already present, which represents a volume in the peritoneum of 106% in the first cycle, 112% in the second cycle, etc. In this example, there are two possible protective measures. The first is to reduce the volume injected in the filling phases by 3%. The second is to impose a complete drainage phase at the end of 8 cycles. On balance, the cumulative errors over 8 cycles represent a maximum volume in the peritoneum of 100%+8×3%, namely 124%, which is an acceptable volume. Possible Methods: [0105] The document further discloses a method for controlling a medical system according to a defined treatment in order to achieve a collection of objectives, the method comprising: providing a dialysis system which comprises: a processor designed to control the medical system according to at least two modes of operation: a mode of normal operation determined by a first collection of parameters making it possible to achieve substantially all of the objectives defined by the treatment a mode of safe operation determined by a second collection of parameters that does not allow all of the objectives defined by the treatment to be achieved but that does allow the treatment to be performed substantially, a sensor designed to send signals to the processor, determining at least one condition of operation, receiving and analyzing the signals from the sensor, automatically selecting the mode of normal operation or the mode of safe operation according to the signal analysis and/or said at least one condition of operation, controlling the medical system according to the mode of operation selected. [0115] The system described hereinabove may be designed to operate according to several modes of safe operation. Also, the processor may switch from one mode of safe operation to another mode of safe operation progressively. [0116] According to one embodiment, the medical system comprises a pump controlled by the processor and designed to displace a medical fluid. The medical system may, for example, be a dialysis system. [0117] Optionally, the method may comprise the following step: adapting at least one condition of operation according to the mode of operation selected. [0118] According to one embodiment, the parameter may be: the duration of the treatment, a volume of medical fluid displaced by the pump, a volume of medical fluid used, the temperature or the pressure of the displaced fluid or the delivery rate of the pump. If the medical device comprises a pump, then the mode of safe operation may be characterized by a pump delivery rate that is not as high as in the mode of normal operation. [0119] For preference, the processor during treatment may switch from one mode of operation to another defined mode of operation according to the signal analysis and/or to said at least one condition of operation. [0120] If the treatment is a peritoneal dialysis then the dialysis system may be designed to perform several successive cycles comprising an injection phase in which the system injects the medical fluid into the peritoneum of the patient, a stasis phase in which the medical fluid remains in the patient's peritoneum for a determined length of time, and a drainage phase in which the pump removes the fluid from the patient's peritoneum. In that case, the parameter(s) may be: the duration of each stasis phase, the total volume of fluid injected into and/or removed from the peritoneum, the volume of fluid injected into the peritoneum during an injection phase, the volume of fluid removed from the peritoneum during a drainage phase, the number of cycles, the duration of the phases or the delivery rate of the pump in the injection and/or drainage phase. Furthermore, during a mode of safe operation, the processor may be designed to command a complete forced drainage of the peritoneum at least once before the end of the treatment. Optionally, the processor may be designed to perform several forced drainages at defined intervals. [0121] According to one embodiment, the mode of safe operation may be designed to decrease the risk of overfilling the patient's peritoneum during the treatment. Further, the medical device may be designed to estimate the risk of overfilling or underfilling the patient's peritoneum. [0122] For preference, one condition of operation is: the status of the sensor, a drift in the sensor measurement, the crossing of a threshold or the leaving of a predefined domain, or a discrepancy in the measurement against another sensor. The sensor may be a pressure sensor or a temperature sensor. [0123] The document discloses another method designed to control a dialysis apparatus. This other method may comprise the following steps: observing at least one parameter relating to the dialysis determining a first acceptable range of values for said parameter. [0126] For preference, the switchover from one mode of operation to a first mode of safe operation if the data of said at least one parameter are outside said first range of acceptable values. The observed parameter may be the volume of dialysate displaced to and/or from a patient's peritoneum. [0127] The method may also comprise: the following additional steps: determining a second range of acceptable values for said parameter switching from the first mode of downgraded operation to a second mode of safe operation if the data of said at least one parameter are outside said second range of acceptable values. And/or the following additional steps: determining an nth range of acceptable values for said parameter switching from the n−1th mode of downgraded operation to an nth mode of safe operation if the data of said at least parameter are outside said nth range of acceptable values. Other Possible Embodiments [0134] The document discloses a system for medical use which may comprise a pump, means for estimating a volume of fluid displaced by the pump, means for operating said pump according to the objectives defined for the treatment; in which said pump is designed to deliver a fluid to a patient or to remove a fluid from a patient. The operating means may determine a mode of operation of the pump as a function of data sent by the means of estimating displaced volume. Furthermore, at least one mode of operation may be a safe mode allowing the system to continue the treatment in order to get close to at least one of the objectives defined for the treatment in the event of at least part of the operating and/or estimating means being potentially defective, while at the same time limiting the risks to the patient. [0135] The operating means may change the mode of operation without the intervention of the patient or of the care personnel. The treatment may correspond to that of a peritoneal dialysis and may comprise at least two cycles of fill and drain phases. [0136] Optionally, during a safe mode, the operating means may reduce the volume of fluid displaced during at least one fill phase and/or increase the volume of fluid displaced during at least one drain phase. [0137] At least one of the objectives may be the treatment time, the quantity of ultrafiltrate removed, the volume of fluid delivered to the patient's peritoneum and/or the volume of liquid removed from the patient's peritoneum, and/or the total dialysis time performed. The means of estimating the displaced volumes may comprise one or more pressure sensors or volumetric chambers. The means of estimating the displaced volumes may comprise one or more temperature and/or viscosity sensors, or calibration means. In such a case or cases, the estimating means may be redundant and at least one of the two means may be deemed to be potentially defective, thus leading to the safe mode being activated. The redundant estimation means may deviate from one another by a certain amount at least. The filling phase of each cycle in safe mode may be reduced by at least 1% of the prescribed volume. The drainage phase of each cycle in safe mode may be increased by at least 1% of the prescribed volume, if the prescribed drainage is not a total drainage. The most complete possible drainage may be imposed during at least one drain phase if the potential overfilling of the peritoneal cavity as a result of the cumulative effect of the various preceding cycles crosses a threshold of between 120 and 180%. [0138] According to one embodiment, the automated dialysis apparatus is designed to perform peritoneal dialysis on a patient and may comprise a pump operated by a controller and designed to displace at least a first defined volume of dialysate from dialysate supply means into the peritoneal cavity of the patient during a fill phase and to remove at least a first defined volume of dialysate from the patient's peritoneal cavity during a drain phase. The apparatus may further comprise a sensor connected to the controller and designed to estimate the volumes of dialysate displaced during at least one of these two phases. [0139] For preference, the apparatus comprises at least two modes of operation one of them being a mode of operation that allows all the defined objectives to be achieved and at least one other being a mode of safe operation designed to come close to at least one of said defined objectives without ever achieving it, while at the same time ensuring patient safety. The mode of operation may be determined by the controller without the intervention of the patient or of the care personnel, for example as a function of the estimate of the volumes displaced. [0140] For preference, the mode of safe operation may be actuated by the controller as soon as an error in the estimation of the volumes is possible or detected. The mode of safe operation may be determined by the controller as soon as the data from the sensor cross a certain measurement threshold or exhibit a certain difference with respect to the expected measurement. The mode of safe operation may be designed to reduce the delivery rate of the pump or the duration of the treatment or at least a volume of dialysate delivered during at least one fill phase. [0141] According to one embodiment, the apparatus may comprise several successive safe modes which allow treatment to be continued but which increasingly diverge from at least one of the defined objectives. The controller may select one of the safe modes according to the measurements from at least one of the sensors. The controller may progressively modify its mode of operation until the measurements from the sensor fall within a predefined range. [0142] According to one embodiment, the peritoneal dialysis system may comprise a liquid pump, means for operating said pump. Where the pump is designed to deliver or remove a liquid to or from the peritoneal cavity of a patient and the system may be configured to operate according to at least one of the following two modes of operation: a first mode of operation referred to as normal defining a first collection of parameters intended to achieve a given treatment effectiveness a second mode of operation referred to as safe defining a second collection of parameters intended to achieve: minimum effectiveness of the treatment, and/or effectiveness lower than the effectiveness of the first embodiment, while ensuring patient safety during the treatment. [0147] In another embodiment, the system may be configured to operate according to at least one of the following two modes of operation: a first mode of operation referred to as normal adhering to the parameters defined by a given prescription a second mode of operation referred to as safe which does not adhere to at least one of the parameters defined by said prescription but which guarantees patient safety until the end of the programmed treatment. [0150] According to one possible embodiment, the automated dialysis apparatus is designed to perform peritoneal dialysis on a patient in accordance with a collection of parameters defined by a given prescription guaranteeing a certain treatment effectiveness. The apparatus may comprise a liquid pump, means of operating said pump according to parameters defined by a given prescription. Where the pump is designed to deliver or remove a liquid into or from the peritoneal cavity of a patient and the apparatus is configured to modify at least one of said parameters so as to perform substantially the entirety of the treatment while at the same time guaranteeing patient safety. However, the new parameters might not allow the expected effectiveness to be achieved, in response to a suspected at least partial deficiency with an element (for example a sensor, a pump) to operate said dialysis apparatus correctly.

A medical system suitable for delivering a fluid to a patient according to multiple modes of operation, including a safety mode that additionally enables the delivery or the treatment to continue even when a probable anomaly is detected.

CROSS-REFERENCE TO RELATED APPLICATIONS Not applicable. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not applicable REFERENCE TO A "MICROFICHE APPENDIX" Not applicable BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the disassembly or unthreading of pipe, specifically of oil and gas well drilling pipe and more particularly to an improved method and apparatus for enabling a user to disassemble or destab joints of oil field drill pipe and the like even in offshore marine conditions, e.g. on semisubmersible rigs and the like. Even more particularly, the present invention relates to an improved destabbing apparatus and its method of use wherein a cylindrically shaped sleeve having a hinged body enables the sleeve to be assembled and disassembled to a pair of connected joints of pipe, the lower end of the sleeve having a cam and clamp arrangement that securely fastens the sleeve to the lower of the two pipe joints enabling a user to "destab" (disassemble) the upper joint while the sleeve grips the lower joint. 2. General Background of the Invention In the oil and gas well drilling industry, it is common to employ drill strings that are comprised of a number of lengths of drill pipe that are connected end to end. In some particular types of joints such as those that employ wedge threads, dovetail threads, taper threads and the like, excess thread wear and thread damage can more easily occur during destabbing operations. Further, rough seas cause floating oil well drilling vessels to pitch so that aligning pipe sections is difficult. BRIEF SUMMARY OF THE INVENTION The present invention provides an improved method of destabbing or disconnecting a pair of threadably interengaged and generally vertically oriented oil and gas well drill pipe sections that are connectable end to end at threaded pin and box joint connections. The method first provides a pair of pipe joints to be joined, each having end portions with mating faces and threaded portions that are connected to similarly threaded portions of another joint. During destabbing, a sleeve is affixed to the assembly of the pipe joints at the mating faces, wherein a lower end portion of the sleeve engages the lower joint and an upper end portion of the sleeve engages the upper joint. The joints are then "destabbed" by rotating the upper joint relative to the lower joint and wherein the sleeve tightly engages the lower joint. During this method, the longitudinal axes of the joints are maintained in alignment. The present invention also provides a pipe destabbing apparatus for disconnecting a pair of threadably connected pipe joints having threaded end portions and mating faces at the end portions. The apparatus includes a sleeve having a pair of connected sections, means on the sleeve sections for enabling a user to manipulate the sleeve sections during use, at least one of the sleeve section having a window, the lower end of the sleeve having a compressive member for pressing the sleeve against the lower joint of the pair of assembled joint of pipe, and wherein the window enables the user to position the mating faces at the middle of the sleeve by visual inspection. The upper end of the sleeve closely conforms to the upper joint of pipe and the compressive member applies sufficient load to the assembled joints at the lower joint so that when the two joints are rotated with respect to one another during disassembly or destabbing, the lower joint is affixed to the sleeve and the upper joint rotates with respect to the sleeve and lower joint. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the preferred embodiment of the apparatus of the present invention; FIG. 2 is a perspective view of the preferred embodiment of the apparatus of the present invention illustrating the destabbing of one joint of pipe from another joint of pipe; FIG. 3 is a perspective view of the preferred embodiment of the apparatus of the present invention; and FIG. 4 is a top view of the preferred embodiment of the apparatus of the present invention; FIG. 5 is a top view of the preferred embodiment of the apparatus of the present invention showing the body in an open position; FIG. 6 is an elevational view of the preferred embodiment of the apparatus of the present invention; and FIGS. 7-8 are fragmentary views showing the locking cam position. For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein: DETAILED DESCRIPTION OF THE INVENTION FIGS. 1-6 show generally the preferred embodiment of the apparatus of the present invention designated generally by the numeral 10. Destabbing apparatus 10 includes a cylindrically shaped sleeve in the form of two semicircular clamp sections 21, 22 as shown in FIGS. 1-4. In the oil and gas well drilling industry, stabbing means to thread one joint of drill pipe that is vertically oriented into another joint of drill pipe that is vertically oriented such as occurs when running a drill string into the well. "Destabbing" refers to the disassembly or unthreading of an upper vertically oriented joint from a lower joint, such as occurs when pulling a pipe string out of a well. In FIGS. 2 and 6, a pair of joints of drill pipe are connected end to end including a lower joint 11 and an upper joint 12. The lower joint 11 provides a box end portion 13. The upper joint 12 provides a pin end portion 14. Each of the joints 11, 12 provides a longitudinally extending, typically cylindrically shaped open ended flow bore 15, 16 respectively. Each of the joints 11, 12 provides a wall 17, 18 respectively. In FIG. 1, a rotation of the upper joint 12 with respect to the lower joint 11 in the direction of arrow 19 enables the threads at the box and pin end portions 13, 14 to be disassembled or "destabbed" so that the joint 12 can be separated from the joint 11 in the direction of arrow 20. In FIGS. 1-5, destabbing apparatus 10 is the form of a cylindrically shaped sleeve that includes clamp sections 21, 22 connected together with upper and lower hinges 23. Handles 24, 25 enable a user to grip the respective clamp sections 21, 22 during assembly and during disassembly of the apparatus 10 to a pair of connected joints 11, 12. A pair of windows 26, 27 are provided respectively upon clamp sections 21, 22 as shown in FIGS. 1, 2, 3 and 6. The windows 26, 27 enable a user to place the apparatus 10 in the correct position upon a pair of assembled joints 11, 12. Preferably, the respective lower end portions 45, 46 of the windows 26, 27 are placed immediately below the upper transverse surface 47 of the lower joint 11, a distance indicated by arrow 48 as shown in FIG. 6. In this fashion, the user ensures that the apparatus 10 will be clamped to the upper end of the lower joint 11. Because the upper end portion of the clamped sections 21, 22 are not provided with a clamp mechanism (such as the mechanism 40 at the bottom of the apparatus 10), only the bottom part of the apparatus 10 is tightly clamped to the lower joint 11. This construction enables the upper joint 12 to rotate freely with respect to the clamp sections 21, 22 during destabbing. Each of the clamp sections 21, 22 provides and upper annular edge 28 and a lower annular edge 29. The windows 26, 27 are space downwardly from the upper annular edge 28 and upwardly from the lower annular edge 29 as shown in FIG. 3. Clamp mechanism 40 is shown more particularly in FIGS. 3-4 and 6-8. Clamp mechanism 40 is mounted at weldment 42 to clamp section 21. The weldment 42 carries a square block like body 39 with a central longitudinal bore 43 through which threaded fastener 37 passes. Threaded fastener 37 attaches at hinge 36 to link 32. The opposite end of threaded member 37 carries washer 41 and nut 43. Spring 38 is positioned in between body 39 and washer 41 as shown in FIG. 4. Handle 33 is pivotally attached at pivot 34 to link 32. Cam 35 at one end of handle 33 is provided for engaging the recess 31 of catch 30. In order to close clamp sections 21, 22, a user holds knob 47 of handle 33 and manipulates the handle 33 until cam roller 49 engages the recess 31. The user then rotates the handle 33 in the direction of arrow 44 in FIGS. 4 and 8. Cam roller 49 engages recess 31 of catch 30 that is welded to clamp section 22. Continued rotation of handle 33 in the direction of arrow 44 similarly rotates cam roller 49 in the direction of arrow 50. Cam links 51, 52 nest in between links 32 as shown in FIGS. 4, 6-7 as closure is completed. Tension in spring 38 can be varied by tightening or loosening nut 37 on threaded fastener 37 to vary the distance between washer 41 and block 39. When handle 33 is rotated to the fully closed position of FIG. 4, threaded fastener 37 moves relative to bore 43 so that spring 38 can be compressed to load the connection of cam roller 49 to catch 30. The inside surfaces of clamp sections 21, 22 are curved to conform to the outer surfaces of pipe sections 11, 12. However, the inside surfaces of the clamp sections 21, 22 can be slightly cut away above a horizontal line 53 that is also represented by transverse face 47 of lower joint 11 (see FIG. 6). Such a cut-away surface could be a few, for example only a few tenths of a millimeter, allowing upper joint 12 to rotate a little more freely relative to lower joint 11 during destabbing. However, it has been found that the inside surfaces 54, 55 of respective clamp sections 21, 22 can define a cylinder with uniform transverse cross section since clamp mechanism 40 tightly grips lower section 11 during destabbing. The following table lists the parts numbers and parts descriptions as used herein and in the drawings attached hereto. ______________________________________PARTS LISTPart Number Description______________________________________10 destabbing apparatus11 joint12 joint13 box end14 pin end15 flow bore16 flow bore17 wall18 wall19 arrow20 arrow21 clamp section22 clamp section23 hinge24 handle25 handle26 window27 window28 upper edge29 lower edge30 catch31 recess32 link33 handle34 pivot35 cam36 pivot37 threaded member38 spring39 body40 clamp mechanism41 washer42 weldment43 nut44 arrow45 lower end portion46 lower end portion47 knob48 arrow49 cam roller50 arrow51 cam link52 cam link53 line54 inside surface55 inside surface______________________________________ The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.

A method and apparatus for destabbing (disassembling) two vertically oriented drill pipe joint sections provides a two part clamp arrangement that holds the assembled joint at their interface. A lower end of the clamp arrangement is tightly clamped to the lower joint so that the upper joint rotates when the two joint are gripped with power tongs or like pipe handling devices and unthreaded or "destabbed".

The research leading to the present invention was supported, at least in part, by grant CA42567 from the National Cancer Institute, also by funds from the NIH Medical Scientist Training Program (grant number GM07739). Accordingly, the Government may have certain rights in the invention. BACKGROUND This invention relates to the field of enzyme inhibitors, especially inhibitors of histone acetyltransferases. The molecular identification of a number of histone acetyltransferases (HATs) has led to new insights into the mechanisms of activation of gene expression (Mizzen and Allis, 1998; Stuhl, 1998). The members of this growing family include the important transcription factors p300/CBP and PCAF (Yang et al., 1996; Ogryzko et al., 1996; Bannister and Kouzarides, 1996). PCAF and p300/CBP can catalyze the acetylation of histones (Yang et al., 1996; Ogryzko et al., 1996; Bannister and Kouzarides, 1996) and other substrates (Wu and Roeder, 1997) and these HATs have been suggested to play differential roles in coactivation of gene expression. The HAT domain of PCAF appears to be involved in MyoD-dependent coactivation and differentiation, whereas that of p300 seems to be less important (Puri et al., 1997). A role for the acetyltransferase activity of PCAF was also suggested for transcriptional activation by the liganded retinoic acid receptor (RAR). The PCAF acetyltransferase domain but not that of CBP can assist retinoic acid induced transcription in cultured cells that are depleted of endogenous PCAF and CBP by antibody microinjection (Korzus et al., 1998). On the other hand, the acetyltransferase domain of CBP and not that of PCAF can contribute to CREB-activated transcription in PCAF- and CBP-depleted cells (Korzus et al., 1998). These experiments suggest differential requirements for PCAF and p300/CBP in the coactivation of various sequence-specific DNA binding transcriptional activators. However, none of these studies has established directly that acetyltransferase action or histone acetylation per se is involved in these activation processes. Because of the possibility that PCAF and p300 proteins physically interact (Ogryzko et al., 1996), their relative contributions toward acetylation of substrates and gene activation is not generally known. While mutations in the active site regions of these enzymes can help clarify these issues, the effects of such mutations on altering protein structure and stability can complicate interpretations. Small molecules have been useful in elucidation of the general role of histone acetylation in transcription by blocking histone deacetylase (Taunton et al., 1996). It would be advantageous to apply active-site directed, specific, and potent synthetic inhibitors of individual HAT enzymes to dissect their relative roles in protein acetylation and transcription. Furthermore, there is a basis for expecting that the blockade of p300 HAT activity would have therapeutic potential in the treatment of certain cancers (Giles et al., 1998). Prior to the molecular characterization of specific HAT enzymes, several polyamine-CoA conjugates were found to block HAT activities present in cell extracts (Cullis et al., 1982; Erwin et al., 1984). However the actual enzyme or enzymes inhibited have not been characterized. We have shown that one of these synthetic inhibitors (Cullis et al., 1982) potently blocks non-chromatin template mediated transcription and therefore would not be useful in the determination of the role of HAT activity in gene activation unpublished data. PCAF belongs to a superfamily of GNAT (GCN-5 related N-acetyltransferases) acetyltransferases whose three-dimensional structures have recently been reported (Coon et al., 1995; Neuwald and Landsman, 1997; Wolf et al., 1998; Dutnall et al., 1998; Wybenga-Groot et al., 1999; Hickman et al., 1999a; Hickman et al., 1999b; Lin et al., 1999). Family members most likely catalyze acetyl transfer in a ternary complex containing enzyme, histone, and acetyl-CoA (De Angelis et al., 1998; Tanner et al., 1999). Bisubstrate analog inhibitors have proved successful for the GNAT family member serotonin N-acetyltransferase (Khalil et al., 1998; Khalil et al., 1999). Here we report on bisubstrate analog inhibitors and their effects on histone acetylation and transcription. SUMMARY OF THE INVENTION The invention in a general aspect is a histone acetyltransferase inhibitor. Such inhibitors are useful both as analytical reagents for studying the role of histone acetyltransferases in the regulation of gene expression. They are also useful for inhibiting acetyltransferase in diseased cells that overexpress such acetyltransferase. In a particular embodiment of the invention, the inhibitor is Coenzyme A (CoA) covalently linked (preferably via a —CO— bridge to a lysine ε-amino group) to lysine or a polypeptide comprising lysine. Inhibitors that are specific for p300 acetyltransferase are those in which the CoA is linked to lysine or a very short polypeptide (2 to 6 amino acids) comprising lysine. Such inhibitors will inhibit p300 acetyltransferases (“p300 inhibitors”) more significantly (at least 100 times as much) than they inhibit PCAF acetyltransferases. Inhibitors that are specific for PCAF acetyltransferases (“PCAF inhibitors”) are those in which the CoA is linked to lysine in longer polypeptides (8 or more amino acids.) Such inhibitors will inhibit PCAF acetyltransferases (“PCAF inhibitors”) more significantly (at least 100 times as much) than they inhibit p300 acetyltransferases. In another aspect, the invention is histone acetylase inhibitors that will inhibit transcription of a histone-associated DNA sequence more strongly than the identical DNA sequence not associated with histones (especially, naked DNA). Such inhibitors are the p300 inhibitors and PCAF inhibitors. In another general aspect, the invention is the process of administering a histone acetyltransferase inhibitor to a host, the host being an animal or human. Such a process is done for therapeutic purposes in cases where it is beneficial to the host to have a histone acetyltransferase inhibited. That is the case, for example, in certain types of cancers. It can also be the case in certain gene therapy protocols. A preferred histone acetyltransferase inhibitor of the present invention is one with the structure where the H is [CHR 11 ] is absent if R 11 is oxygen where n is an integer in the range 0 to 2; where R 1 , R 2 , and R 10 are independently selected from the group consisting of hydrogen, methyl, ethyl, propyl, butyl, pentyl, vinyl, ethinyl, allyl, methyloxy, ethyloxy, propyloxy, butyloxy, and pentyloxy; where R 11 for each R 11 is independently selected (e.g., if n is 3, there are three R 11 moieties that can be independently selected) from the group consisting of hydrogen, methyl, ethyl, propyl, butyl, pentyl, vinyl, ethinyl, allyl, methyloxy, ethyloxy, propyloxy, butyloxy, pentyloxy fluoro, chloro, bromo, iodo, hydroxy, carboxy, and oxygen, where carboxy is wherein R 12 is hydrogen, methyl, ethyl, propyl, or isopropyl, where R 8 is selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl, vinyl, ethinyl, allyl, methyloxy, ethyloxy, propyloxy, butyloxy, pentyloxy, an amino acid or a polypeptide comprising two amino acids, provided that if R 8 is an amino acid or polypeptide, said amino acid or polypeptide may have a protective group (e.g., it is acetylated) at its N terminus. The intent of the protective group is to provide ptrotection during the compound's synthesis. Where R 9 is selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl, vinyl, ethinyl, allyl, methyloxy, ethyloxy, propyloxy, butyloxy, pentyloxy, an amino acid acetylated at its N terminus, or a polypeptide of two or more amino acids; and pharmaceutically acceptable salts thereof. Inhibitors of interest that are analogs of Lys-CoA are also shown in FIG. 7, (R 6 and R 7 in FIG. 7 correspond to R 8 and R 9 , respectively.) For H3-20-CoA analogs of interest include those with substitutions in the lysine moiety similar to those shown for Lys-CoA. In addition, truncations and substitutions of the other amino acids in the peptide backbone using combinatorial approaches can be performed to create analogs. Specific embodiments of interest are: those wherein R 8 , in combination with the carbonyl group adjacent to R 8 , is an amino acid or a polypeptide of two or more amino acids; those wherein R 9 is an amino acid or a polypeptide of two or more amino acids; those wherein R 8 , in combination with the carbonyl group adjacent to R 8 , is an amino acid of a polypeptide of two or more amino acids, and R 9 is an amino acid or a polypeptide of two or more amino acids. Specific inhibitors of p300 acetyltransferase are preferably: those wherein R 8 , in combination with the carbonyl group adjacent to R 8 , is an amino acid, especially where the amino acid is Gly; those wherein R 9 is an amino acid or a polypeptide of 2 or 3 amino acids, especially where R 9 is selected from the group consisting of Gly, Gly-Leu, and Gly-Lys-Gly (such that the leftmost amino acid is the one closest to the NH group adjacent to the R 9 group); and those where wherein R 8 is methyl and R 9 is hydrogen (also referred to as Lys-CoA herein). Specific inhibitors of PCAF acetyltransferase are preferably: those wherein R 8 , in combination with the carbonyl group adjacent to R 8 , is a polypeptide comprising at least three amino acids, especially where the three amino acids are those of Gly-Gly-Thr and in that sequence; those wherein R 8 , in combination with the carbonyl group adjacent to R 8 , comprises a polypeptide of at least 8 amino acids especially where the eight amino acids are those of Thr-Ala-Arg-Lys-Ser-Thr-Gly-Gly- (SEQ ID NO:1) and in that sequence: those wherein R9 is a polypeptide of at least 5 amino acids, especially where the 5 amino acids are those of Ala-Pro-Arg-Lys-Gln (SEQ ID NO:2) and in that sequence; and those where R8 is (N-acetyl)-Ala-Arg-Thr-Thr-Lys-Gln-Thr-Ala-Arg-Lys-Ser-Thr-Gly-NH-CH 2 - in that sequence, wherein the peptide portion of R 8 is SEQ ID NO:3, and R9 is the polypeptide Ala-Pro-Arg-Lys-Gln-Leu (SEQ ID NO:4) in that sequence. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 . Design and synthesis of peptide CoA conjugates. FIG. 1 A: Coupling reactions. FIG. 1 B: Peptide synthesis FIG. 2 . Evaluation of Lys-CoA as a HAT inhibitor. FIG. 2 A: Autoradiographic analysis of p300 HAT inhibition by Lys-CoA. Lanes 1-5 employed 0, 0.1, 0.5, 2.5, and 10 μM concentrations of Lys-CoA. Images bands are histones H4 (top) and H3 (bottom). FIG. 2 B: Bar graph analysis of p300 HAT Inhibition by Lys-CoA at the concentrations indicated, quantitated using Phosphorimage analysis (Molecular Dynamics). HAT activity is normalized to 100% for no added inhibitor. FIG. 2 C: Bar graph analysis of PCAF HAT Inhibition by Lys-CoA at the concentrations indicated, quantitated using Phosphorimage analysis (Molecular Dynamics). HAT activity is normalized to 100% for no added inhibitor. Standard error was found to be ±20% for duplicate runs. The sequence Ala-Pro-Arg-Lys is SEQ ID NO:5. The sequence Gly-Leu-gly-Lys is SEQ ID NO:6. The sequence Ala-Arg-Thr-Lys-Gln-Thr-Ala-Arg-Lys-Ser-Thr-Gly-Gly, which is represented in the Figure in reverse direction (from right to left), is SEQ ID NO:8. The sequence Ala-Pro-Arg-Lys-Gln-Leu is SEQ ID NO:4. The sequence Ser-Gly-Arg-Gly-Lys-Gly-Gly, which is represented in the Figure in reverse direction is SEQ ID NO:9. The sequence Gly-Leu-Gly-Lys-Gly-Gly-Ala-Lys-Arg-Asn-Arg-Ala is SEQ ID NO:10. The entire sequence for H3-CoA-7 is SEQ ID NO:11. The entire sequence for H4-CoA-7 is SEQ ID NO:12. The entire sequence for H3-CoA-20 is SEQ ID NO:13. The entire sequence for H4-CoA-20 is SEQ ID NO:14. FIG. 3 . Assessment of p300 and PCAF HAT activities in p300/PCAF. FIG. 3 A: p300 and PCAF HAT activities with mixed histones as substrates. Bar 1, PCAF alone without inhibitors; Bar 2, p300 alone without inhibitors; Bar 3; PCAF+p300 without inhibitors; Bar 4, PCAF+p300+Lys-CoA (30 μM); Bar 5, PCAF+p300+H3-CoA-20 (30 μM); Bar 6, PCAF+p300+Lys-CoA (30 μM)+H3-CoA-20 (30 μM). Activities were normalized to 100% for Bar 3. Standard error was found to be ±20% for duplicate runs. FIG. 3 B: p300 and PCAF HAT activities with nucleosomes as substrates. Bar 1, PCAF alone without inhibitors; Bar 2, p300 alone without inhibitors; Bar 3; PCAF+p300 without inhibitors; Bar 4, PCAF+p300+Lys-CoA (20 μM); Bar 5, PCAF+p300+H3-CoA-20 (15 μM); Bar 6, PCAF+p300+Lys-CoA (20 μM)+H3-CoA-20 (15 μM). Activities were normalized to 100% for Bar 3. Standard error was found to be ±20% for duplicate runs. FIG. 4 . Lys-CoA inhibits p300 HAT activity dependent transcription activation. FIG. 4 A: Outline of the in vitro transcription protocol. FIG. 4 B and C: Transcription from naked DNA and chromatin templates. DNA (28 ng) and freshly assembled chromatin templates (with an equivalent amount of DNA) were incubated with or without activator, Gal4-VP16 (30 ng) for 20 min at 30° C.; 25 ng of baculovirus expressed, highly purified p300 (full length) and 1.5 μM of acetyl-CoA were added as indicated. Following the addition of nuclear extract (source of general transcription factors) and NTPs, transcription reactions were incubated and processed as described. Before adding it to the reaction, p300 was incubated (4° C., 20 min) with or without inhibitors: without inhibitor (panel C, lanes 2 and 9), 10 μM Lys-CoA (panel C, lanes 3 and lane 10) or H3-CoA-20 (Panel C, lanes 4 and 11). FIG. 5 . Acetyl-CoA. FIG. 6 . Cell permeable analog development. FIG. 7 . Inhibitory lysine analogs. FIG. 8 . Evaluation of H3-CoA-20 as a HAT inhibitor. FIG. 8 A: H3-CoA-20 p300 HAT inhibition. FIG. 8 B: H3-CoA-20 PCAF inhibition. DETAILED DESCRIPTION OF THE INVENTION Amino acid abbreviations “Ala” represents alanine, “Asn” represents asparagine, “Lys” represents lysine, “Leu” represents leucine. “Thr” represents threonine, “Ser” represents serine, “Arg” represents arginine, “Pro” represents proline, “Gln” represents glutamine. Pharmaceutical aspects of the invention In a preferred embodiment, a prodrug represented by Lys-X is used in order that enzymes within the cell, especially HAT enzymes, can catalyze alkyl transfer to CoASH so as to generate the potent p300 inhibitor Lys-CoA within the cells. Lys-X is expected to be cell permeable because it is small, relatively hydrophobic and unchanged. Upon conversion to Lys-CoA within cells, it would be “trapped” in the cell and thereby a potent p300 inhibitor. (See FIG. 6.) This strategy was shown to be effective in a related system with serotonin N-acetyltransferase (E. M. Khalil et al., PNAS, vol. 96, pp. 12418-12423, 1999). In another option, Lys-pantetheinyl derivatives are administered. The further elaboration of Lys-panteheine or Lys-pant-phosphate within cells can be predicted based on the known cellular enzymes that convert pantetheine and phosphopantetheine to coenzyme A. (See FIG. 6.) Indeed, we have shown (unpublished data) that this appears to take place for an indole-pantetheine derivative. A general approach to making peptide agents cell permeable is to covalently attach them to short membrane permeable sequences (Rojas M. Donahue JP. Tan Z. Lin YZ. Genetic engineering of proteins with cell membrane permeability. Nature Biotechnology, 16(4):370-5, 1998 April and references therein). This is another option for both Lys-CoA and H3-20-CoA. 4) Liposomes and cationic lipids might also be used to deliver the HAT inhibitors inside cells. Pharmaceutical preparations of the compounds of the invention would include pharmaceutically acceptable carriers, or other adjuvants as needed, and would be prepared in effective dosage ranges as needed. Generally, the inhibitors (or precursors thereof capable of being correctly processed in the host or the host's cells) of the invention may be formulated for intraarterial, intraperitoneal, intramuscular, subcutaneous, intravenous, oral, nasal, rectal, bucal, sublingual, pulmonary, topical, transdermal, or other routes of administration. Comprehended by the invention are pharmaceutical compositions comprising effective amounts of inhibitors of the invention together with pharmaceutically acceptable diluents, preservatives, solubilizers, emulsifiers, adjuvants and/or carriers. Such compositions include, for example, aqueous diluents of various buffer content, incorporation of the material into particulate preparations of polymeric compounds such as polylactic acid, polyglycolic acid, etc. or into liposomes. The compositions may be prepared in liquid form, or may be in dried powder, such as lyophilized form. Solid dosage forms include tablets, capsules, pills, troches or lozenges, cachets or pellets. Also, liposomal or proteinoid encapsulation may be used to formulate the present compositions (as, for example, proteinoid microspheres). Liposomal encapsulation may be used and the liposomes may be derivatized with various polymers. Appropriate dosage levels for treatment of various conditions in various patients will depend on the patient and the therapeutic purpose. Generally, for injection or infusion, dosage will be between 0.01 μg of biologically active inhibitor/kg body weight and 10 mg/kg. The dosing schedule may vary, depending on the circulation half-life of the inhibitor (or its precursor) whether, for example, the inhibitor is delivered by bolus dose or continuous infusion, and the formulation used. Results and discussion We synthesized Lys-CoA and the other peptide CoA conjugates shown in FIG. 1 . Modification of the ε-amino group of the lysine was carried out in one pot, first coupling the amine with bromoacetic acid followed by reaction of the α-bromo-acetamide function with CoASH (FIG. 1 A). Partially, protected peptides were produced by solid phase peptide synthesis using the Fmoc strategy. Selective modification of the desired lysine in the context of other lysine residues was achieved using orthogonal protection with the dimethyldioxocyclohexylidene (Dde) protective group. It was necessary to carry out the CoA conjugation step after cleaving the peptides from the resin because of the presumed lability of the lycosidic linkage in CoA in the presence of strong acid conditions. Each peptide CoA conjugate (FIG. 1B) was purified to homogeneity (>95%) by reverse phase HPLC, and electrospray mass spectrometry was used to verify structural integrity. These compounds were stable in solution under long term storage conditions (>6 mos) at −80° C. Screening of the peptide CoA conjugate for inhibition of HAT activity of PCAF and p300 was carried out according to standard HAT assay procedures (Ogryzko et al., 1996; Yang et al., 1996; Schiltz et al., 1999) using commercially available mixed calf histone substrates. As can be seen, Lys-CoA was found to be a potent and selective inhibitor of p300 acetyltransferase activity with an IC 50 of approximately 500 nM (FIG. 2, Table 1). Under similar conditions, the IC 50 of Lys-CoA for PCAF inhibition was approximately 200 μM. Neither of the heptapeptide-CoA conjugates was effective at inhibiting p300 or PCAF (Table 1). H3-CoA-20 proved to be very effective at inhibiting PCAF HAT activity (IC 50 =300 nM) but showed little ability to block p300 (IC 50 =200 μM) (FIG. 8, Table 1). Interestingly, H4-CoA-20 was a poor inhibitor of both p300 and PCAF (Table 1). Neither the H3-20 peptide (which lacked CoA attachment) nor CoASH itself were potent HAT inhibitors (Table 1). That the H3-CoA-20 conjugate required the covalent attachment of the histone H3 20 amino acid peptide to CoASH was confirmed by showing that an equimolar mixture of free peptide and CoASH was poorly able (IC 50 >10 μM) to block PCAF HAT activity (data not shown). Regarding inhibition results with PCAF, there is enhanced inhibition by an H3-20-CoA conjugate over an H4-20-CoA conjugate, a degree of selectivity >100-fold). Inhibition of PCAF was not achieved by the shorter conjugate H3-CoA-7. This suggests that key binding interactions between the PCAF enzyme and the histone H3 substrate lie outside the nearest neighboring residues and are mediated more broadly over the substrate sequence. The potent inhibition of p300 by Lys-CoA but by none of the other peptide-CoA conjugates was an unexpected finding. That incorporation of longer peptide sequences derived from the histone H4 or H3 substrate into the bisubstrate analog actually reduces binding affinity is not readily explicable. These results are particularly striking since Lys-CoA actually lacks positive charges, a hallmark of the N-terminal regions of the substrates histone H3 and histone H4. These findings strongly suggest that p300 has a significantly different catalytic mechanism or mode of substrate binding compared to PCAF and other GNAT superfamily members, reflecting its lack of sequence homology. With potent and specific HAT inhibitors in hand, one can exploit these molecules in further biochemical analysis. Since p300 and PCAF may form a complex and since each catalyzes acetyltransferase activity, the availability of inhibitors allows an opportunity to investigate the precise contributions of each enzyme present in a PCAF/p300 mixture toward histone acetylation. As can be seen in FIG. 3A, the combination of PCAF and p300 (present together) leads to an increased histone acetylation rate compared to either enzyme working alone (compare bars 1 and 2 with bar 3). In principle, this increase could have arisen in two ways: i) simple summing of the two enzyme activities without synergism or antagonism, or ii) stimulation of enzyme A by enzyme B with concomitant antagonism of enzyme B by enzyme A. Here, application of Lys-CoA and H3-CoA-20 inhibitors proved useful in distinguishing between these possibilities. It was observed that in the presence of Lys-CoA, the PCAF/p300 mixture resulted in acetylation that was similar to the rate of PCAF alone (compare bar 1 and bar 4) whereas in the presence of H3-CoA-20, the PCAF/p300 mixture resulted in acetylation that was similar to the rate of p300 alone (compare bar 2 and bar 5). Moreover, addition of both Lys-CoA and H3-CoA-20 to the PCAF/p300 mixture abolished nearly completely histone acetylation (bar 6). Furthermore, the pattern of histone acetylation (histone H3 vs. H4) reflected that expected for PCAF in the presence of Lys-CoA and that expected for p300 in the presence of H3-CoA-20 (data not shown). These results suggest that with purified histone mixtures, PCAF and p300 act independently when present together (without synergism or antagonism) to acetylate histones. Given that physiologic substrates for p300 and PCAF are likely to be histones bound to DNA in nucleosomal structure, it was important to establish that selectivity of the inhibitors Lys-CoA and H3-CoA-20 could be achieved in this setting. As nucleosomes are much poorer substrates for HAT enzymes compared to free histones, it was necessary to use larger quantities of each of the enzymes (˜5-10-fold greater) and allow acetylation to take place for a longer period of time (˜40-fold greater) to achieve adequate signal to noise. In this way it was shown that Lys-CoA was still selective for p300 inhibition and H3-CoA-20 was still selective for PCAF blockade (using 20 μM Lys-CoA, greater than 90% p300 inhibition was achieved while less than 10% PCAF inhibition occurred; using 15 μM H3-CoA-20, greater than 90% PCAF inhibition was observed with less than 10% p300 inhibition detected, data not shown). Experiments with mixtures of PCAF and p300 and nucleosome substrate showed the same pattern of histone acetylation in the presence of inhibitors as observed for the free histone substrates (compare FIG. 3 A and 3 B). Thus it can be concluded the p300 and PCAF act independently in histone acetylation of nucleosomes as substrates. This is noteworthy since higher concentrations of HATs were used in the nucleosome experiments, which would be expected to encourage p300-PCAF interaction. An important application of selective HAT inhibitors is to use them as tools in studies of transcriptional regulation. Given the limited ability of CoA conjugates to penetrate cell membranes (Robishaw and Neely, 1985), it was advantageous to evaluate these compounds in an in vitro chromatin-based transcription system. In this regard, we exploited a recently developed in vitro chromatin-transcription system that appears to require the HAT activity of full length p300 for the function of transcriptional activators (data not shown). The strategy designed for these experiments is outlined in FIG. 4 A. The chromatin template was reconstituted by incubation of purified proteins (HeLa core histones, NAP1 and rh TopoI) with a 5.4 kb plasmid (p20855G5MLC2AT) that contains a 690 bp promoter region (5 Gal4 binding sites and the adenovirus major late promoter with a G-less cassette) flanked on both sides by the 5 nucleosome positioning sequence from the sea urchin 55 rRNA gene (Cote et al., 1995). Assembled chromatin was structurally characterized by supercoiling and micrococcal nuclease (MNase) assay (data not shown). The chromatin template was nearly completely inert even in the presence of Gal-VP16 activator (FIG. 4B, lane 7). In contrast, an equimolar amount of the corresponding DNA template showed a high level of activator-dependent transcription that was 15-fold above the basal transcription (FIG. 4B, lanes 1 vs 2) and independent of the presence of p300 and/or acetyl-CoA (FIG. 4B, lane 2 vs 3-5). Addition of p300 along with Gal-VP16 activator had a negligible effect in activating transcription from the chromatin template (FIG. 4C, lane 8). However, addition of 1.5 μM acetyl-CoA along with p300 and Gal-VP16 activator increased transcription ˜10-fold compared to the reaction without acetyl-CoA addition (compare FIG. 4C, lanes 8 vs 9), suggesting a role for the p300 HAT activity in the observed transcription activation. Preincubation of p300 with the p300 selective HAT inhibitor Lys-CoA (10 μM) completely abolished the p300 and acetyl-CoA dependent transcription activation from the chromatin template (FIG. 4C, lanes 10 vs 9). Similar pretreatment of p30 with the PCAF selective inhibitor, H3-20-CoA (10 μM) marginally inhibited (˜30%) the p300 HAT activity dependent transcription (FIG. 4C, lanes 9 vs 11) consistent with the expected specificity of the inhibitors. As a control, it was shown that the effect of these two inhibitors on naked DNA transcription was minimal, Lys-CoA inhibited naked DNA transcription only 15-20% (average of 4 independent experiments) and H3-20-CoA did not affect transcription at all (FIG. 4C, lanes 2 vs 3 and 4). These data establish directly the role of p300 HAT activity in this transcriptional system. Further studies showed that baculovirus expressed full length PCAF had no effect on activator dependent transcription from the chromatin template in either the presence or absence of p300 under the conditions we have tested (data not shown). It was a formal possibility that PCAF could be recruited to the promoter in the presence of p300, and provide a redundant HAT function that did not further increase transcription. However, this possibility was ruled out by showing that Lys-CoA abolished transcriptional activation in the presence of p300-PCAF mixtures just as it did with p300 alone (data not shown). In summary, these studies report the design, synthesis, and evaluation of the first selective HAT inhibitors. These HAT inhibitors were used to quantify the contributions of the interacting HATs p300 and PCAF in histone acetylation and revealed an additive but non-synergistic interaction between the PCAF and p300 HAT activities in the systems investigated. Furthermore, the p300-selective inhibitor, Lys-CoA, showed a specific inhibition of p300 and acetyl-CoA dependent transcription from a chromatin template, directly demonstrating the importance of the p300 HAT activity in transcriptional enhancement in an in vitro system. Applications employing selective HAT inhibitors as biological tools in a variety of contexts can now be pursued. Experimental procedures Lys-CoA synthesis Synthesis of Lys-CoA was carried out as follows: N-acetyl-lysine-amide hydrochloride (Ac-Lys-NH 2 , 50 mg, 224 mmol), bromoacetic acid (31 mg, 224 mmol), 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (EDC, 43 mg, 224 mmol), and triethylamine (31.1 ml, 224 mmol) were dissolved in 4 mL N,N-dimethylformamide (DMF). After stirring under nitrogen at room temperature (12 h), more bromoacetic acid (31 mg, 224 mmol) and EDC (43 mg, 224 mmol) were added to the reaction. After an additional 4 h, the mixture was concentrated in vacuo. The residue was dissolved in 4 mL aqueous 1 M triethylammonium bicarbonate (pH 8.0)/4 mL methanol, CoASH (129 mg, 155 mmol) was added, and the reaction was stirred overnight under nitrogen for a total of 15 hours, Lys-CoA was purified from this solution by preparative reverse phase C-18 HPLC. The compound was eluted (t R =30 min, λ=260 nm) at a constant flow rate of 10 mL/min with 100% aqueous 50 mM KH 2 PO 4 (pH 4.5) for 5 minutes, followed by a linear gradient to 40% methanol over 35 minutes, Lys-CoA was desalted by preparative C-18 HPLC at a constant flow rate of 10 mL/min, eluting with 100% H 2 O (0.05% TFA) for 30 min, followed by a linear gradient to 100% methanol over 5 min. then 100% methanol for 20 min to elute the compound (t R =41 min). The methanol was removed on a rotary evaporator and the compound was dissolved in H 2 O and lyophilized for 48 hr. The compound (51 mg, 23% yield) appeared >95% pure by analytical reversed phase C-18 HPLC. 1 H NMR (400 MHz, D 2 O), and electrospray mass spectrometry, which showed data in full accord with the reported structure. Peptide CoA Conjugate Syntheses Peptide CoA conjugates and other peptides (H3-CoA-7, H4-CoA-7, H3-CoA-20, H4-CoA-20, H3-20, H4-20) were synthesized using the solid phase fluorenylmethoxycarbonyl peptide synthesis strategy on a Rainin PS-3 machine. The N-terminal residues were used in the α-amino acetylated forms and the C-terminal residues were the free acids for the 20 aa peptides (obtained with Wang resin) and the carboxamides for the 7 aa peptides (obtained with Rink amide resin). Note that lysine residues that were not conjugated with CoA were orthogonally protected with Dde (dimethyldioxocyclohexylidene) ε-NH 2 group) whereas the others were protected with tert-butoxycarbonyl groups. Peptides were cleaved from the resin and deblocked with trifluoroacetic acid in reagent K which left the Dde group intact and then reacted as described above with excess bromoacetic acid (˜4 equivalents) and CoASH (˜5 equivalents), followed by Dde removal via hydrazinolysis (3% aqueous hydrazine at room temperature, 2-3 h). For standard peptides (H3-20 and H4-20), Dde groups were removed without carrying out the CoA coupling steps. Peptides were purified by preparative reversed phase C-18 HPLC (H 2 O:CH 3 CN: 0.5% trifluoroacetic acid). Peptides appeared >95% pure using analytical reversed phase C-18 HPLC and showed the predicted molecular mass using electrospray mass spectrometry. HAT Activity Inhibition Assays Full length PCAF and p300 proteins were prepared and purified according to previously described methods (Schiltz et al., 1999). HAT inhibition assay procedures were adapted from previously described methods (gryzko et al., 1996; Yang et al., 1996; Schiltz et al., 1999). Briefly, substrate concentrations were 10 μM acetyl-CoA (NEN, 14 C, 0.02 μCi/μL), 33 μg/mL mixed histones (Boehringer); buffer conditions-50 mM Tris-HCl (pH 8), 10 mM sodium butyrate 1 mM phenylmethyl sulfonyl fluoride, 1 mM dithiothreitol, 0.1 mM N,N,N′,N′-ethylenediamine tetraacetic acid and 10% v/v glycerol. Reactions employed purified recombinant p300 and PCAF (Schiltz et al., 1999) at concentrations of 6 nM and 27 nM, respectively. A range of at least 5 inhibitor concentrations were used. Assays were carried out in 0.5 mL plastic tubes at 30° C. and the reaction volumes were 30 μL. Reactions were initiated with the radioactive acetyl-CoA (4 μL) after allowing the enzyme/buffer/histone/inhibitor mixture to equilibrate at 30° C. for 10 min, and reactions quenched after 1 min with 7.5 μL 5×SDS gel load. Mixtures were run out on 15% SDSPAGE visualized with Coomassie blue, dried, and radioactivity quantified by phosphorimage analysis (Molecular Dynamics). In all cases, background acetylation (in the absence of enzyme) was subtracted from the total signal. All assays were performed at least twice and duplicates generally agreed within 20%. IC 50 values were estimated from bar graph plots (see FIG. 2 for an example) and estimated standard errors on these values are ±20%. For nucleosomes (Cote et al., 1995), enzyme concentrations were 24 nM for p300 and 432 nM for PCAF and reactions were allowed to proceed for 40 min before quenching (nucleosome concentrations had approximately equal amount of protein visualized by SDSPAGE as the mixed histone reactions). Transcription studies Native HeLa nucleosome was prepared as described elsewhere (Cote et al., 1995). Human core histones were purified as described elsewhere (Kunda et a, 1998). Recombinant His 6 -tagged nucleosome assembly protein 1 (NAP1) and transcription activator Gal4-VP16 were expressed in E. coli and purified with nitrilloacetic acid-agarose (Qiagen) as specified by the manufacturer. Baculovirus expressed recombinant human topoisomerase I (rh TopoI) and full length p300 were purified as described previously (Wang and Roeder, 1996; Kraus and Kadonaga, 1998). Chromatin template for transcription studies were assembled on a ˜5.4 kb plasmid (p2085S G5MLC2AT) with purified human core histones, rh TpopI, and NAP1 as described (T. K. K. et al., manuscript in preparation). Prior to use in the transcription experiment, assembled, chromatin was subjected to supercoiling and Mnase assay. In vitro transcription assays were carried out in 50 μL reaction mixtures containing either 28 ng of DNA or an equivalent amount of chromatin. 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(1998) Crystal structure of a GCN5-related N-acetyltransferase: Serratia marcescens aminoglycoside 3-N-acetyltransferase. Cell 94, 439-449. Wybenga-Groot, L. E., Draker, K.-a., Wright, G. D., and Berghuis, A. M. (1999) Crystal structure of an aminoglycoside 6′-N-acetyltransferase defining the GCN5-related N-acetyltransferase superfamily fold. Structure 7, 497-507. Yang, X.-J., Ogryzko, V. V., Nishikawa, J., Howard, B. H., and Nakatani, Y. (1996) A p300/CBP-associated factor that competes with the adenoviral oncoprotein E1A. Nature 382, 319-324. Figure Legends 1) FIG. 1 . Design and Synthesis of Peptide CoA Conjugates. (A) General scheme for CoA coupling to the lysine ε-NH2 groups. (B) Peptide CoA conjugates evaluated for HAT inhibition. See Experimental Procedures for synthetic details. 2) FIG. 2 . Evaluation of Lys-CoA as a HAT Inhibitor. (A) Autoradiographic analysis of p300 HAT inhibition by Lys-CoA. Lanes 1-5 employed 0, 0.1, 0.5, 2.5, and 10 μM concentrations of Lys-CoA. Imaged bands are histones H4 (top) and H3 (bottom). See Experimental Procedures for details. (B) Bar graph analysis of p300 HAT Inhibition by Lys-CoA at the concentrations indicated, quantitated using Phosphorimage analysis (Molecular Dynamics). HAT activity is normalized to 100% for no added inhibitor. (C) Bar graph analysis of PCAF HAT Inhibition by Lys-CoA at the concentration indicated, quantitated using Phosphorimage analysis (Molecular Dynamics). HAT activity is normalized to 100% for no added inhibitor. Standard error was found to be ±20% for duplicate runs. 3) FIG. 3 . Assessment of p300 and PCAF HAT Activities in p300/PCAF Mixtures. (A) p300 and PCAF HAT activities with mixed histones as substrates. Bar 1, PCAF alone without inhibitors; Bar 2, p300 alone without inhibitors; Bar 3; PCAF+p300 without inhibitors; Bar 4, PCAF+p300+Lys-CoA (30 μM); Bar 5, PCAF+p300+H3-CoA-20 (20 μM); Bar 6, PCAF+p300+Lys-CoA (30 μM)+H3-CoA-20 (30 μM). Activities were normalized to 100% for Bar 3. Standard error was found to be ±20% for duplicate runs. In a separate experiment done under identical conditions with the individual enzymes, it was shown that Lys-CoA (20 μM) and H3-CoA-20 (15 μM) blocked p300 and PCAF HAT activity greater than 90%, respectively, and showed less than 10% inhibition with PCAF and p300, respectively (data not shown). See Experimental Procedures for details. (B) p300 and PCAF HAT activities with nucleosomes as substrates. Bar 1, PCAF alone without inhibitors; Bar 2, p300 alone without inhibitors; Bar 3; PCAF+p300 without inhibitors; Bar 4, PCAF+p300+Lys-CoA (20 μM); Bar 5, PCAF+300+H3-CoA-20 (15 μM); Bar 6, PCAF+p300+Lys-CoA (20 μM)+H3-CoA-20 (15 μM). Activities were normalized to 100% for Bar 3. Standard error was found to be ±20% for duplicate runs. In a separate experiment done under identical conditions with the individual enzymes, it was shown that Lys-CoA (20 μM) and H3-CoA-20 (15 μM) blocked p300 and PCAF nucleosome acetylation activity greater than 90%, respectively, and showed less than 10% inhibition with PCAF and p300, respectively (data now shown) See Experimental Procedures for details. 4) FIG. 4 . Lys-CoA inhibits p300 HAT activity dependent transcription activation. (A) Outline of the in vitro transcription protocol. (B) and (C) Transcription form naked DNA and chromatin templates. DNA (28 ng) and freshly assembled chromatin templates (with an equivalent amount of DNA) were incubated with or without activator, Gal4-VP16 (30 ng) for 20 min at 30°, 25 ng of baculovirus expressed, highly purified p300 (full length) and 1.5 μM of acetyl-CoA were added as indicated. Following the addition of nuclear extract (source of general transcription factors) and NTPs, transcription reactions were incubated and processed as described (T. K. K. et al., manuscript in preparation). Before adding it to the reaction, p300 was incubated (4° C., 20 min) with or without inhibitors; without inhibitor (pane C, lanes 2 and 9), 10 μM Lys-CoA (panel C, lanes 3 and lane 10) or H3-CoA-20 (Panel C, lanes 4 and 11). TABLE 1 Compound IC 50 with p300 (μM) IC 50 with PCAF (μM) CoASH 200 >20 H3-20 — >20 H3-CoA-7 >30 >20 H3-CoA-20 200 0.3 H4-CoA-20 >10 >10 Lys-CoA 0.5 200 Table 1 provides IC 50 values for synthetic compounds with CoASH. Substrate concentrations were: [acetyl-CoA]=10 M, [mixed histones]=33 μg/mL. Assays were performed as described in Experimental Procedures. The IC 50 values are identified as the concentrations of compound necessary to cause 50% inhibition of the acetyltransferase reaction. The values written as ‘>10 μM’ or ‘>20 μM’ indicate that less than 50% inhibition was observed at these inhibitor concentrations (the upper limit used in the particular assay). Standard errors on all values are estimated to be ±20%. 14 1 8 PRT Artificial Sequence Description of Artificial Sequence PART OF SYNTHETIC MOLECULES THAT ACT AS ENZYME INHIBITORS 1 Thr Ala Arg Lys Ser Thr Gly Gly 1 5 2 5 PRT Artificial Sequence Description of Artificial Sequence PART OF SYNTHETIC MOLECULES THAT ACT AS ENZYME INHIBITORS 2 Ala Pro Arg Lys Gln 1 5 3 13 PRT Artificial Sequence Description of Artificial Sequence PART OF SYNTHETIC MOLECULES THAT ACT AS ENZYME INHIBITORS 3 Ala Arg Thr Thr Lys Gln Thr Ala Arg Lys Ser Thr Gly 1 5 10 4 6 PRT Artificial Sequence Description of Artificial Sequence PART OF SYNTHETIC MOLECULES THAT ACT AS ENZYME INHIBITORS 4 Ala Pro Arg Lys Gln Leu 1 5 5 4 PRT Artificial Sequence Description of Artificial Sequence PART OF SYNTHETIC MOLECULES THAT ACT AS ENZYME INHIBITORS 5 Ala Pro Arg Lys 1 6 4 PRT Artificial Sequence Description of Artificial Sequence PART OF SYNTHETIC MOLECULES THAT ACT AS ENZYME INHIBITORS 6 Gly Leu Gly Lys 1 7 12 PRT Artificial Sequence Description of Artificial Sequence PART OF SYNTHETIC MOLECULES THAT ACT AS ENZYME INHIBITORS 7 Ala Arg Thr Lys Gln Thr Ala Arg Lys Ser Thr Gly 1 5 10 8 13 PRT Artificial Sequence Description of Artificial Sequence PART OF SYNTHETIC MOLECULES THAT ACT AS ENZYME INHIBITORS 8 Ala Arg Thr Lys Gln Thr Ala Arg Lys Ser Thr Gly Gly 1 5 10 9 7 PRT Artificial Sequence Description of Artificial Sequence PART OF SYNTHETIC MOLECULES THAT ACT AS ENZYME INHIBITORS 9 Ser Gly Arg Gly Lys Gly Gly 1 5 10 12 PRT Artificial Sequence Description of Artificial Sequence PART OF SYNTHETIC MOLECULES THAT ACT AS ENZYME INHIBITORS 10 Gly Leu Gly Lys Gly Gly Ala Lys Arg Asn Arg Ala 1 5 10 11 7 PRT Artificial Sequence Description of Artificial Sequence SYNTHETIC MOLECULE THAT ACT AS ENZYME INHIBITOR 11 Gly Gly Lys Ala Pro Arg Lys 1 5 12 7 PRT Artificial Sequence Description of Artificial Sequence SYNTHETIC MOLECULE THAT ACT AS ENZYME INHIBITOR 12 Gly Gly Lys Gly Leu Gly Lys 1 5 13 20 PRT Artificial Sequence Description of Artificial Sequence SYNTHETIC MOLECULE THAT ACT AS ENZYME INHIBITOR 13 Ala Arg Thr Lys Gln Thr Ala Arg Lys Ser Thr Gly Gly Lys Ala Pro 1 5 10 15 Arg Lys Gln Leu 20 14 20 PRT Artificial Sequence Description of Artificial Sequence SYNTHETIC MOLECULE THAT ACT AS ENZYME INHIBITOR 14 Ser Gly Arg Gly Lys Gly Gly Lys Gly Leu Gly Lys Gly Gly Ala Lys 1 5 10 15 Arg Asn Arg Ala 20

Histone acetyltransferase inhibitors, especially those that are differentiate between p300 and PCAF histone acetyltransferase; also therapeutic processes comprising their administration to humans.

FIELD OF THE INVENTION [0001] This invention relates to a system for producing customizable speech for use by a person wishing to use such speech to communicate with others. The spoken words may be in any language and the person may be one who does not speak the spoken language or be speech impaired. The spoken language is fully customizable for the user. BACKGROUND OF THE INVENTION [0002] 1. Portable Artificial Speech Systems (PASS) Overview [0003] Speech is the fastest method of casual communication, among hearing people. It is obvious that individuals lacking the ability to speak, whether due to being speech-impaired and/or lacking knowledge of a desired language, would desire a portable device to enable them to communicate by spoken word. Unfortunately, current art does not support a perfect Portable Artificial Speech System (PASS). Therefore, current art devices involve various compromises, that are strong in some areas and weak in others. Portable Artificial Speech Systems current art is summed up as follows: [0004] 1. Input Source Language. [0005] 2. Apply Computer Processing and/or Artificial Intelligence (AI). [0006] 3. Output Target Language. PRIOR ART RELATING TO INPUT DEVICES [0007] Input devices include: standard keyboards; Multi-use keyboards (Mikulsi 4,503,426) (Baker 5,299,125), Buttons (Maruta 5,523,943; 5,530,644; 5,606,498; 5,868,576) (Seno, 5,991,711) (Kind 5,275,818); Touchpad (Little 4,908,845); Tablet (Takeuchi 5,875,421), (Forest 6,005,549); Iconic Graphical User Interface (Steele 5,169,342); Single Switch (5,047,953); Sign Language Gloves (Sakiyama 5,659,764; 5,953,693); and even Speech (Rondel 4,984,177) (Alshawi 5,870,706). Also included in Input Devices would be methods to speed input such as (Ichbiah 5,623,406) system to speed keyboard entry through the use of custom defined abbreviations. The use of these different devices involve various trade-offs. For example, a standard keyboard is perhaps the slowest input device, but is also the most accurate. Speech Input requires a very high level of complexity to translate the source language, with a decrease in accuracy, but is (in theory) easy to use. Button input is generally desired for small devices. Single switch input is vital for individuals with serious physical impairments, while a Touch Display input is quite useful for individuals with less serious physical impairments. PRIOR ART RELATING TO ARTIFICIAL INTELLIGENCE (AI) [0008] The problems of creating artificial speech are compounded by the complexity of speech itself; the added meaning which comes from intonation and body language; differences in grammar and inflection between different languages; and finally language that is dependent on social environment. The purpose of the AI is to take the source language input and prepare it for output in the target language. There are many different methods to accomplish this. The simplest breaks Source Language into words then translates it through use of a dictionary, word by word. Doi (4,791,587) improves on this method by submitting homonyms for user intervention. Hutchins (4,994,966) does grammar checking on Source Language to ensure greater accuracy of translation. Kaji (5,020,021) examines Source Language for missing elements, such as pronouns. Fukumochi (5,321,607) uses parsing trees on the Source Language, identifies phrases with possible multiple meanings, and refers same to user. Tolin (4,864,503 and 5,490,061) translates the Source Language to Esperanto and then to Target Language. Stentiford (5,384,701 and 5,765,131) searches Source Language for keywords that correspond to a stored phrase. Maruta (5,523,943 etc.) uses phrase matching, where a user is presented a limited number of phrases in a source language that are matched with phrases in the target language. Kanno ( 5 , 406 , 480 ) builds and analyzes co-occurrences. Kaplan (5,523,946 and 5,787,386) translate the Source Language into a Pivot Language and thence to the Target Language, reducing computer resource required to translate to multiple languages. Kutsumi (5,826,219) is able to reduce compound sentences in Source Language to simpler phrases allowing more accurate translation. Kawamura (6,009,443) identifies and displays conjugation combinations of person and tense. Suda (6,023,669) bases translation of Source Language on the social situation Target Language is to be used. Takeuchi (5,875,421) uses a query system wherein a user enters a desire such as “I am thirsty” and the device queries user about particulars to guide user to a particular stored phrase in Target Language. PRIOR ART RELATING TO OUTPUT DEVICES [0009] The object of an output device is to provide as natural speech as possible. The simplest device is a voice synthesizer that is given the Target Language one phoneme at a time, and speaks one phoneme at a time (as opposed to entire words). The output from this method is very artificial. The step up is a Word Matching system, where the voice synthesizer is given the Target Language one word at a time. This is an improvement, but the words are spoken which equal pauses between them, which still sounds artificial. Additionally, by speaking one word at a time, most emotional content is lost, creating artificially sounding speech. Phrase matching devices may send entire phrases to a voice synthesizer, resulting in less artificial sounding speech. Seno (5,991,711) is a combination of phrase matching with phonemes. This allows it to smoothly say “I live at” and then ‘sound out’ the address using phonemes. Joyce (4,908,845) requires the user to acquire, edit and digitize phrases. Kind (5,275,818) provides the user phonemic pronunciation of Target Language for user to speak. Engelke (5,974,116) relies on a live interpreter. DESIRED QUALITIES OF A PORTABLE ARTIFICIAL SPEECH SYSTEM (PASS) [0010] To date it has not been possible to make a perfect Portable Artificial Speech System (PASS). All current systems include certain trade-offs. The perfect PASS would be; Accurate (technical, syntactic), Affordable, Responsive, Customizable (contents, interface, output), Upgradeable, Easy to Use, and provide Feedback to the user. Below is a discussion of how various trade-offs affect these qualities. [0011] A. Accuracy [0012] There are two types of Accuracy to be considered; Technical and Syntactic. Technical Accuracy refers to how accurately the Source Language is translated into the Target Language. For example, Source “My dog I love” is translated into Target as “My dog I love.” Syntactic Accuracy refers to how accurately the translation follows the Target Language's syntactic rules. For example, the Source “My dog I love” with English as the target, would be more Syntactically Accurate if translated as “I love my dog.” [0013] Technical Accuracy begins with accurate input. A positive input device, such as a button or keyboard is more accurate that a translated input, such as from a Speech Recognition System. A button system such as Maruta (5,523,932 etc.) leaves very little room for inaccuracies. A system using a keyboard is more flexible than a button system but is open to misspellings in the Source language input and thus generating an incorrect translation. A speech recognition system, such as Alshawi (5,870,706) is easy to use and very flexible, yet being a more complex system is more likely to produce inaccurate input, thus leading to inaccurate translation. [0014] The most Technically Accurate Artificial Intelligence (AI) system is one that employs phrase matching, such as Maruta (5,523,943 etc.). By the use of matching pairs of phrases (Source and Target) accuracy is ensured. The trade-off with such a system is that the user is limited in both input and output. The user is required to choose only from phrases stored in the system. A system using keywords to stored phrases, such as Stentiford (5,384,701) allows more input flexibility at the expense of accuracy. This type of system does not restrict the user's input. It scans the input for keywords in the source language, which it matches with stored phrases in the target language. The most flexible systems do not use phrase matching. Any user input is allowed (Source) and an attempt is made to accurately translate it. The problems with homonyms (Doi, 4,791,587) and inflection (Kawamura, 6,009,443) alone, illustrate that this flexibility is matched by a decline in accuracy. [0015] Technical Accuracy in Output devices can be assessed by how natural the output speech sounds to a listener in the target language. A phrase system such as Stentiford (5,384,701) is able to produce more natural speech with a trade-off in flexibility. A word-by-word system is more flexible with a corresponding trade-off in how natural it sounds. [0016] There are a number of systems described in the art that provide grammatical accuracy of translations. They can be broadly categorized by whether they employ Phrase Matching or not. A Phrase Matching system stores a complete phrase in the Target Language to ensure accuracy. The only source of inaccuracy would be if multiple phrases are combined in an incorrect manner. The phrase matching system trades off flexibility for accuracy. A non-phrase-matching system is obviously less accurate but more flexible. [0017] B. Affordability [0018] When reviewing current art it becomes obvious that various systems involve trade-offs between flexibility and affordability. For example, Engelke (5,974,116) requires use of a mobile phone plus a live human translator, obviously very flexible but also costly and likely not always conveniently available. A device such as Takeuchi (5,875,421) is designed to be affordable but it is not very flexible. AI systems trade-off system requirements (hardware on which the AI runs) and affordability. Systems such as Suda (6,023,669) are high on system requirements and thus less affordable, but provide better translations, than less system intensive systems. [0019] C. Responsive [0020] For purposes of this discussion responsive refers to Lag Time. Lag Time is the time period from when a user determines (in their mind) a desired phrase to be spoken and when that phrase is actually spoken. Lag Time in a known language would be 0. An example may be helpful here. John is in an airplane and does not speak the language of the flight attendants. A flight attendant brings John a drink. Upon examining his drink John determines he would like extra ice. Lag time is measured from when John determines he would like extra ice and when his Portable Artificial Speech System speaks. Every system will have different lag times depending on the particular situation. A system such as Takeuchi (5,875,421) is designed for use by casual travelers, and so will have a very small lag time, but sacrifices flexibility for this. A speech recognition system which requires the user to validate the input, trades-off ease of use and flexibility for an increase in lag time. [0021] D. Customizable [0022] Three areas of Portable Artificial Speech Systems can be customized; the input device, the AI, and the output. Ichibiah (5,623,406) is a system which customizes keyboard input through the use of custom abbreviations. Seno (5,991,711) is an example of AI customization. It allows a user to enter a custom noun in selected phrases. Ideally the voice spoken by the Portable Artificial Speech System should match the user's own voice or for a speech-impaired user, a voice that matches a user's expected voice (male/female deep/high). [0023] E. Upgradeable [0024] Language changes constantly. Especially in technical fields, language changes very quickly. Just a few years ago terms such as, “email”, “dot com” and “world wide web” were not in common use. Currently, any PASS used for business communication would be considered defective if it could not deal with these terms. A device such as Maruta (5,530,644) which limits its scope to the casual needs of tourists does not require upgradeability, as a tourist's general needs do not change. However, a more universal phrase matching system would need to be upgradeable. A system that can output words phonetically is less concerned with upgradeability than a system which requires a complete word. [0025] F. Ease of Use [0026] All Portable Artificial Speech Systems work well in a controlled environment, such as a business office or hotel room. Not all PASS work equally well in day to day environments such as in the back of a taxi, or at a streetside vendor. Devices which use keyboards are not as easy to use as devices which use buttons or devices which use speech input. [0027] G. Operating Feedback [0028] Ideally the PASS should provide the user with adequate visual feedback that it is operating properly, keeping in mind that a user will not understand and/or through impairment hear the target language spoken. THE FAST FOOD RESTAURANT TEST [0029] It can be seen from the foregoing discussion that there are no perfect Portable Artificial Speech Systems. They all have different functionality, and are useful in certain situations. However, they all fail the Fast Food Restaurant Test. [0030] The Fast Food Restaurant Test assumes a user knows at the beginning of the day that s/he is going to lunch with a group of people. The group could have gone to any number of restaurants, but voted to go to McDonalds®. Upon studying the menu a user decides s/he desires a Big Mac® Meal, supersized, and hold the pickles. Some of the PASS could not form this speech, while others would require an unacceptable lag time. THE TAKE ME OUT TO THE BALLPARK TEST [0031] This test assumes a user is in a hotel and desires to go to a Baseball Game and return to the hotel. In order to accomplish this, a user will need to have a number of casual conversations. To fellow elevator passenger—“press lobby please”. To doorman—“cab please”. To cab driver—“take me to Riverfront Stadium”. To food vendor—“I would like one chili dog and a beer.” To vendor—“I would like this T-shirt”. To ballplayer—“would you autograph this please”. To seat neighbor—“can I get you anything?” To fellow fan—“pardon me—coming through” To cab driver—“Ramada Hotel, on Elm” To fellow elevator passenger—“press 12 please.” Some of the known PASS could not form this speech, while others would require an unacceptable lag time. Keyboard based systems would be hard to use in these various and often crowded environments. [0032] The present invention has passed these tests by combining the internet, portable computing devices such as PDAs (Personal Digital Assistants) and the availability of cheap memory. SUMMARY OF THE INVENTION [0033] The present invention has as a first objective (a) creating and storing a large number of Digital Speech Audio Files (DSAF) where each DSAF contains a commonly used phrase (b) creating a description of each phrase in one language, although the phrase may be in a second language (c) and providing means to distribute these phrases through electronic and/or physical media. [0034] A second object of the invention is to provide a means of classifying these phrases into various conversational groupings along with a method for identifying and retrieving various conversational groups and subsets. [0035] A third object of the invention is a method for a user to easily edit these conversational groups and/or create custom conversational groups. [0036] A fourth object of this invention is a method for a user to assign a custom code to a particular phrase for rapid retrieval. [0037] A fifth object of this invention is a method for a user to request and retrieve a custom phrase in a timely manner. [0038] A sixth object of this invention is a method for rapid identification of required phrases in most real world environments. [0039] A seventh object of this invention is a method for speaking phrases in most real world environments. [0040] Thus the present invention provides a method for producing customizable audio speech for use by a person wishing to use such speech to communicate with others, which comprises the steps of [0041] a) creating a plurality of sets and sub-sets of words, phrases and sentences in text form in a source language; [0042] b) creating a plurality of sets and sub-sets of digital speech audio files corresponding to words, phrases and sentences in one or more target languages in different voices, by recording the voices speaking the words, phrases and sentences in the one or more target languages; [0043] c) associating each of the words, phrases and sentences in text form in the source language with one or more of the digital speech audio files, in the one or more target languages so that selection of the text form in the source language allows retrieval of the corresponding digital speech audio file in the one or more target languages in a specific voice and storing said associated sets in a central open server in digitized electronic form in a database; [0044] d) organizing said words, phrases and sentences in text form in the source language into conversational social groups and subgroups; [0045] e) coding said words, phrases and sentences, and said conversational social groups and subgroups to allow for rapid retrieval and for customization of same into personal groups and subgroups; [0046] f) means for communicating requests to the central open server for additional words, phrases and sentences in text in source language to be created in additional digital audio files in one or more target languages in one or more voices; which may form part of existing or new conversational social groups and subgroups; [0047] g) creating said additional digital audio files on a closed server for access by the requester only; [0048] h) means for a requester to alter and create new conversational social groups and subgroups; [0049] i) means for playing said selected digital audio speech files so that a user may use such words, phrases and sentences to communicate by speech with others in a selected target language; and [0050] j) means for graphically displaying one or more selected digital audio speech files to verify what is being spoken to the user. BRIEF DESCRIPTION OF THE DRAWINGS [0051] The accompanying drawings are used to illustrate the present invention. [0052] [0052]FIG. 1 is a block diagram illustrating the general concept of the present invention; [0053] [0053]FIG. 2 is a block diagram illustrating an embodiment of the present invention where a modem equipped Personal Digital Assistant uses a Personal PC as a server; [0054] [0054]FIG. 3. is an illustration of server side conversational groupings; [0055] [0055]FIG. 4. is an illustration of server side conversational groupings; [0056] [0056]FIG. 5. is an illustration of a user modified conversational grouping; [0057] [0057]FIG. 6. is an illustration of a user modified conversational grouping with custom phrases; [0058] [0058]FIG. 7. is an illustration of a user made custom conversational grouping; [0059] [0059]FIG. 8. is an illustration of a user defined custom coding of individual phrases; [0060] [0060]FIG. 9 is a flow diagram illustrating an embodiment of the present invention; [0061] [0061]FIG. 10 is an illustration of a sample user interface; [0062] [0062]FIG. 11 is an illustration of how a database for the invention is constructed; and [0063] [0063]FIG. 12 is another illustration of how a database for the invention is constructed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0064] 1. Overview [0065] The preferred embodiments of the present invention will be described with reference to the accompanying drawings. [0066] This invention allows a user to rapidly select and produce artificial speech in an unknown and/or unspeakable language. This invention addresses the problems of speech-impaired users as well as users desiring to speak an unknown language, such as an English speaker wishing to speak Spanish. To provide a more clear example for the reader, this discussion is restricted to a speech impaired user, although the invention is not limited to such an embodiment. In the following discussion, phrase and Digital Speech Audio File will be used interchangeably. It should also be understood that each spoken phrase is associated with a text description. Therefore a single Digital Speech Audio File might be associated with many different source text descriptions, using industry standard computer databases and interfaces. So for the purposes of this discussion, phrase will mean a Digital Speech Audio File in a target language and a text description in a source language. [0067] In another embodiment of the invention, Digitial Speech Audio Files can be associated with icons and/or a text description. [0068] [0068]FIG. 9 is a block diagram of the preferred embodiment of the present invention. 1 Digital Speech Audio Files (DSAF) are created and arranged by source language, target language, voice and conversational groupings. Source Language is a language known to the user. Target Language is the language the user desires to speak in. Voice refers to the qualities of the desired speaking voice, male or female, deep or high, etc. Conversational Groupings refers to organizing phrases in such a manner that phrases that would be used in a particular social situation and/or conversation are kept together for fast identification and retrieval. We will go into more detail of Conversational Groupings later. [0069] In a preferred embodiment of this invention these Digital Speech Audio Files are created from human speech, however this invention is not limited to that form of the invention. Computer generated speech may be substituted for Human speech. This computer generated speech would be checked for accuracy, before becoming a Digital Speech Audio File. [0070] It is anticipated that DSAFs will continuously be created, whether due to (but not limited to) user requests, language changes, fast food menu changes, etc. It is also anticipated that some users would have an onerous burden to electronically acquire all DSAFs that they desire. Therefore 2 these Digital Speech Audio Files are available either through electronic or physical digital media. [0071] The user identifies desired phrases and moves them to a computer 3. For ease of discussion it may be referred to as a home computer. For the preferred embodiment this would be any computer capable of running Microsoft Windows 95® or higher software. If a user requires a custom phrase s/he sends a request to a system operator 4. [0072] Once a user has the desired phrases on a home computer, a user is able to edit existing conversational groupings of phrases, create new conversational groupings and/or assign a custom code to a particular phrase 5. Creating custom conversational groupings is made easy enough that users will be comfortable creating new ones each day, if desired. [0073] Next the user moves the desired phrases in their conversational groupings to a portable computer such as a Pocket PC. The user is able to select various conversational groupings, using a point and click method, and quickly find the desired phrase in such groupings. The Pocket PC would then cause that phrase to be played through its speaker or through an external speaker if greater volume is required 6. Alternatively, a user could enter a short memorized custom code which would cause the playing of a particular phrase. [0074] This is a dynamic customizable system. It is technically and grammatically accurate, as all phrases in the target language are recorded. It is affordable as it has low hardware requirements. It is responsive. A user trades-off some preparation time and is rewarded with very little lag time during conversations. It is customizable. A user can create or acquire different looks (skins) for the user interface of the portable computer. A user can choose between different voices. A user can acquire custom phrases. The system is upgradeable. New phrases can be added and/or new conversational groups created, all of which will be available to users. The system is easy to use. Due to its small size and point and click interface, the system is as easy to use in the back of a cab as it is in a hotel room. Finally, the system will graphically display what phrase it is speaking and that it is functioning correctly. DETAILED DESCRIPTION [0075] A more detailed description of the preferred embodiment will now be described with reference to FIGS. 1 and 2. [0076] A professional speaker 101 is used to create spoken phrases. We define ourselves to the outside world in a number of ways. One of these is clothes. We would not go to a bank for a house loan in a torn t-shirt and shorts. In the same fashion, we would not want to face the world with an inappropriate voice, therefore the use of professional speakers is necessary. Additionally, voice consistency is a desired quality for a Portable Artificial Speech System (PASS). A professional would be more likely to produce consistent speech, even with recording sessions separated by a large amount of time. Finally, speech-impaired individuals have the same sense of humor that speaking individuals do. Therefore this system is able to offer the user celebrity catch phrases, for example Arnold Schwarzenegger saying “I'll be back,” or Bugs Bunny saying “What's up Doc?”. To ensure high quality sound reproduction an audio studio is used to record spoken phrases 102 . [0077] These spoken phrases are recorded, digitized and edited in a state-of-the-art, off-the-shelf system 103 . Each spoken phrase is edited to reduce unwanted noise and to produce an appropriate null pause before and after each phrase. Each spoken phrase is compressed, to reduce storage requirements. Each spoken phrase is then associated with a text description in a source language, using industry standard computer databases and interfaces. These phrases are then placed in appropriate conversational groups (discussed below). [0078] These phrases are then placed on a server 105 . This is described as an open server, as all users will have access to all phrases on this server. Some users will desire custom phrases, such as their name and address, the name and address of a hotel they are staying at, etc. These phrases will be placed on a closed server 106 , with user access granted only to his/her own phrases. One skilled in the art would appreciate that these custom phrases could also be delivered by internet e-mail, other systems of electronic delivery and/or by physical media. [0079] With current art, most users would have an onerous time electronically downloading large numbers of phrases. Therefore, periodically phrases will be placed on physical digital media 104 , such as CD-Roms and DVD-Roms for distribution to users, either through delivery servers 107 or through retail establishments 108 . Users will use the Internet 109 and/or other means of electronic delivery such as direct dial-up, email, etc. to acquire phrases, either individually or in conversational groupings, from the servers. Users will also be able to send requests for custom phrases. [0080] A client or home computer 110 is used to edit and create new custom conversational groupings as desired. This is done using supplied software, using industry standard computer databases and interfaces. In the preferred embodiment this is shown on a home computer capable of running Windows 95 or higher. One skilled in the art would appreciate that other graphical user interface systems such as Mac or Linux could be used. Additionally, as portable computers become more powerful, some or all functions currently shown on a home computer could be performed on a portable computer. Custom codes can be associated with individual phrases as well. [0081] This information is then moved to a portable device such as a Pocket PC®. One skilled in the art would appreciate that there are many such devices that could be used. There currently exists a number of these devices to choose between, and to a certain extent, the device chosen is just personal preference. A larger device, such as a Handheld PC could be used, but its larger size would make it harder to use in some environments. Our preferred embodiment requires a Windows CE capable device that includes audio player means. One skilled in the art would appreciate that other operating systems could be substituted. [0082] Pocket PCs may currently have up to 320 MB added to them. http://www.iis.thg.de/amm/techinf/layer3/index.html shows audio compression rates using MPEG Layer-3 compression, which would be used in a preferred embodiment of the invention. Analyzing the chart, we see that we get 9 minutes of speech per Megabyte with FM radio quality output or 1 minute of speech per Megabyte with CD quality output. Currently Pocket PCs are available with 320 MB plus of storage, allowing the user to carry hours of speech. One skilled in the art would appreciate that other audio compression besides MPEG Layer-3 this could be used. [0083] Pocket PCs come equipped with an MPEG audio reader and an internal speaker. They also come equipped with an audio output to attach an external speaker, if more volume is required. [0084] Physical digital media such as CD-Roms and DVD-Roms are unable to be read with current art small portable computers. FIG. 2 shows the added flexibility available with a Portable Device equipped with a modem 204 . Pocket PCs may be equipped with modems. The Pocket PC, using the Internet or other means of electronic delivery, is then capable of using the home computer 201 along with previously delivered digital physical media 200 as well as the system's servers 202 to download additional phrases while in the field. [0085] Conversational Groups [0086] Conversational Groups will be described with reference to the accompanying drawings, FIGS. 3 - 7 . [0087] Without a method of organizing, the thousands of phrases available for quick retrieval, would be useless. For the purposes of this discussion, a phrase is defined as a Digital Speech Audio File in the Target Language associated with a text file description in the Source Language. For the purposes of quick retrieval, available phrases are organized and grouped according to various social situations. Social situations are as diverse as ordering food at a fast food restaurant and going to a ballpark. By predicting what phrases are appropriate in various social situations and grouping them in Conversational Groups, a user is able to quickly retrieve desired phrases. [0088] [0088]FIG. 3 shows one embodiment of conversational groupings before the user has customized them. The broadest groupings are the highest 300 . Each successive level narrows the groups 300 through 303 . Until at the lowest level 304 , text description of the phrases is shown. On a portable device (such as a PDA) a user carries, this text would be displayed in an industry standard interface. A user would access each level by an industry standard method such as pointing and clicking. So, we can see that a user is just five point and clicks away from having the portable device speak a phrase in the target language. The user points and clicks on Food from group 300 which then displays group 301 . Pointing and clicking on Fast Food from group 301 displays group 302 , which is a list of fast food restaurants. Pointing and clicking on McDonald's from group 302 , displays a list of menu items available from McDonald's 303 . Pointing and clicking on a menu item in group 303 displays various phrases, containing various options for that menu item 304 . Pointing and clicking on One Big Mac® 305 , would have the device speak “I would like to order one Big Mac®, hold the pickles please.” [0089] The text file shown here 305 , is smaller than the actual phrase spoken in the target language. This is to make use of the limited viewing area of a portable device and also to assist user retrieval. This text file is modifiable by a user. [0090] These groupings are customizable at any level. For example if a user never intends to go to a Burger King® s/he can eliminate the Burger Kings® group entirely. Another example would be if a user always orders a Big Mac® with everything, s/he can eliminate any phrases modifying Big Macs®. [0091] [0091]FIG. 4 illustrates a Conversational Group for going to a Baseball Game before user modification. FIG. 5 shows a custom Conversational Group. In this example a user determined what phrases s/he would be likely to speak during a particular baseball game. A user then chooses phrases from different conversational groupings and places them in a new conversational group. In this fashion a user is able to reduce lag time while at the game. [0092] A user creates a new Conversational Group 500 and calls it My Baseball Game. Phrase 501 is retrieved from group 404 . Phrase 502 is retrieved from 402 . Phrase 503 is retrieved from 405 . Phrase 504 is retrieved from 403 , and so on. A user may have both the Baseball Game 400 group as well as the My Baseball Game 500 group on his/her portable device for greater flexibility. [0093] [0093]FIG. 6 illustrates a custom Conversational Group 600 with the addition of custom phrases 605 and 607 . 607 is an example of a phrase that a user would acquire when first using the system, and subsequently add to many conversational groups. 605 is an example of a custom phrase for one time use. [0094] [0094]FIG. 7 illustrates an example of a Custom Conversational Group that a user may use in his/her normal routine. By predicting what phrases the user will want during the day and arranging them in Conversational Groupings, the user is able to quickly find desired phrases, thereby reducing conversational lag. [0095] In addition to using an industry standard interface such as pointing and clicking, to navigate Conversational Groups, users will also be able to assign a custom ID to a particular phrase. FIG. 8 shows an example of custom ID and their related phrase. The use of custom phrases allows Conversational Groups to be smaller, as commonly used phrases such as “Yes” and “No” can be retrieved by inputting a small custom ID, using a standard industry graphical interface. [0096] In another embodiment the user interface would include both text descriptions and icons. [0097] Digital Speech Audio Files [0098] Digital Speech Audio Files are those files which, when played by appropriate software, cause a speaker attached to the computer to “speak” a particular phrase or sentence. Just as an audio CD-Rom is divided into songs, which may be played individually or in any order, Digital Speech Audio Files are phrases, which may be played individually or in any order. [0099] These Digital Speech Audio Files will be organized into Conversational Groupings. Conversational Groupings are unique to our invention. It is a method of organizing phrases in a manner that is easy, fast and convenient for a user to find a particular phrase. Conversational Groupings are discussed in detail elsewhere. [0100] This discussion will concentrate on how these phrases are technically organized on a computer. This is done by using industry standard methods and is not unique to this invention. For the sake of clarity we will discuss two methods of technically organizing our Digital Speech Audio Files, but our invention is not limited to these two. One method is based on directories/file names. The other is based on a database system. [0101] Referring now to FIG. 10, a Digital Speech Audio File, like all files, has two parts, a file name 1001 and digital data 1002 . In a Digital Speech Audio File the digital data consists of audio speech that has been digitized to store on a computer, and which can be played by appropriate software to “speak” through a computer's speaker. In our example, the file name “Hello how are you” describes what the digital data will “say” when played out. The last part of the file name is a suffix, which consists of a period followed by three or more characters. In our example, the suffix .dsa identifies the file as digital audio file. [0102] Files are commonly organized into cascading directories. This organization is reflected in the file name by use of a prefix. Each directory name becomes part of the file name prefix, with each level separated by a “\” character. Referring to FIG. 10 again, both 1002 and 1004 have the same data, that is will “speak” the phrase “Hello how are you. Only their file names are different in 1001 and 1003 . 1003 describes a phrase that is in a directory of Male's voice, a subdirectory of English as a source language and a further subdirectory of English as a target language. In this example, the first directory holds all phrases which are spoken in a male voice. The second directory holds a subset of male voices with English as the source language. The third directory holds a subset of the second directory with English as the target language. Thus, we know from file name 1003 that when played, the file will speak “Hello how are you” in a male voice, in English. We also know that “Hello how are you” will be shown on a user's computer display in the source language, in this case English, as in 1001 . [0103] The digital data in 1002 , 1004 and 1006 are the same. They all speak the phrase “Hello how are you” when played. The only difference between 1020 , 1030 and 1040 is the file name. We know from filename 1005 that the file will speak “Hello how are you” in a male voice, in English. “hola cómo es usted” will be shown on a user's computer display in the source language, in this case Spanish. [0104] We have described two Digital Audio Speech Files that are identical except for their file names, 1030 and 1040 . This is wasteful of computer storage space, as the digitized speech component 1004 and 1006 is repeated. A more efficient way to store these Digital Audio Speech Files is by using a database system, which will be described next. [0105] Referring now to FIG. 11, a database system is a way around the necessity of having to store duplicate data, as in the example discussed above. In a database system, the digitized audio speech 1102 is given a sequential number, 1101 . The information that had been contained in the file name is now contained in a look up table, or database record, 1130 , 1140 . Database records are divided into pieces of information called fields. You will see that database record 1130 has the same information as in the filename of 1030 . Database record 1140 has the same information as in the filename of 1040 . The difference between the two systems is that the database record has a field 1107 and 1112 that references the digitized audio speech 1120 . [0106] The user interface, which is discussed elsewhere, takes information from either the filename or from a database record and displays that information in a way that it is easy, fast and convenient for a user to choose a required phrase. The important point is that there is information associated with each digitized audio speech. This information includes such items such as type of voice, target language, a text description in a source language, etc. [0107] Following is an example of the use of the invention. In this Example Mary, a first-time user, speech-impaired individual uses the present invention. The following example is for illustrative purposes only and is not meant to limit our invention to these particulars. [0108] Mary, A Speech-impaired, First-time User [0109] Mary is speech-impaired. She owns a personal computer (PC) that runs Windows 95®, has a CD player and a modem. Mary has her PC connected to the Internet. She also has a Pocket PC®, which has an internal speaker and a method of connecting to her PC. Mary decides she wants to use our invention, so she goes to her local computer store and purchases a retail version, which comes in a box. When she gets home she opens the box to find a reference manual and a CD. She puts the CD into her computer and runs the installation program. [0110] When the program is first run it collects information to build a user profile. Mary is asked to fill out the following information: [0111] First Name? [0112] Middle Name? [0113] Last Name? [0114] Nickname? [0115] Prefix (r./Miss./Mrs./etc.)? [0116] Home Street Address? [0117] Home City/State/Zip? [0118] Home phone number? [0119] Home email address? [0120] Home TTY number? [0121] Source Language (What language do you want text to be)? [0122] What voice do you want to speak? [0123] Female/Soprano [0124] Female/Mezzo Soprano [0125] Female/Alto [0126] Female/Contralto [0127] Etc. [0128] Work Street Address? [0129] Work City/State/Zip? [0130] Work phone number? [0131] Work email address? [0132] Work TTY number? [0133] Password? [0134] Etc. [0135] The software of the invention then asks Mary to connect to the Internet. Once this is done, her User Profile is uploaded to a central server. Mary is informed that her custom phrases will be available in two to three days and she will be notified by email when they are ready to be downloaded. After Mary receives notification that her custom phrases are ready, she connects to the central server and downloads her custom phrases. As discussed elsewhere, natural speech is spoken in complete phrases. Although individual phrases could be combined together, it would not produce high quality speech, therefore Mary is given a number of similar phrases. She receives a Conversational Grouping titled Mary's Personal Information that contains the following phrases: [0136] Mary's Personal Information [0137] Name [0138] Mary [0139] Alice [0140] Smith [0141] Mar [0142] Mary Smith [0143] Mary Alice Smith [0144] Miss. Smith [0145] Miss. Mary Smith [0146] Miss. Mary Alice Smith [0147] My name is Mary. [0148] My name is Alice. [0149] My name is Mary Smith. [0150] My name is Mary Alice Smith. [0151] My name is Miss. Mary Smith. [0152] My name is Miss. Mary Alice Smith. [0153] Just call me Mar. [0154] My friends call me Mar. [0155] You can call me Mar. [0156] Hello, my name is Mary. [0157] Hello, my name is Alice. [0158] Hello, my name is Mary Smith. [0159] Hello, my name is Mary Alice Smith. [0160] Hello, my name is Miss. Mary Smith. [0161] Hello, my name is Miss. Mary Alice Smith. [0162] Home [0163] 123 Maple Drive [0164] Rockville, Md. 20850 [0165] 301-555-1212 [0166] [email protected] [0167] 301-555-1222 [0168] 123 Maple Drive, Rockville Md. 20850 [0169] 123 Maple Drive, Rockville [0170] My home address is 123 Maple Drive. [0171] My home address is 123 Maple Drive, Rockville, Md. [0172] My home address is 123 Maple Drive, Rockville, Md. 20850 [0173] I'm going to 123 Maple Drive in Rockville [0174] My home phone number is 301-555-1212 [0175] My email is [email protected] [0176] My TTY number is 301-555-1222 [0177] Work [0178] 456 Main Street [0179] Bethesda, Md. 20814 [0180] 301-555-1223 [0181] [email protected] [0182] 301-555-1224 [0183] 456 Main Street, Bethesda [0184] 456 Main Street, Bethesda, Md. 20814 [0185] My work address is 456 Main Street, Bethesda [0186] My work address is 456 Main Street, Bethesda, Md. [0187] My work address is 456 Main Street, Bethesda, Md. 20850 [0188] My work phone number is 301-555-1223 [0189] My work email is [email protected] [0190] My email is [email protected] [0191] My work TTY number is 301-555-1224. [0192] Now Mary is ready to use the invention software to customize her Conversational Groups and her User Interface on her Pocket PC. She starts by creating a new Conversational Grouping for Workday Morning. She first creates a new Group that she names Workdays, and then creates three subgroups called Morning, Afternoon, and Evening. At this point the highest level (Top) Conversational Groupings look like this: [0193] Communication [0194] Emergency [0195] Food [0196] Hobbies [0197] Mary's Personal Information [0198] Mary's Workday [0199] Miscellaneous [0200] Social [0201] Sports [0202] Transportation [0203] If Mary were to choose (double-click on) Mary's Workday she would then have these Conversational Groups to pick from: [0204] Morning [0205] Afternoon [0206] Evening [0207] Turning now to Conversational Groupings again, most casual conversational needs can be known in advance. Daily routines are known, plans can be made ahead. An investment in time in planning ahead will save time in picking an appropriate phrase to speak, out in the field. Essentially Conversational Groupings are a series of cascading directories. Just as with Windows® directories, you can move between them with up arrows, back arrows as well as point and clicking. Each directory contains Speech Audio Digital Files that are related in some fashion. The object of this arrangement is to quickly find a required phrase. [0208] Mary starts work on her Workday Morning Conversational Group by noting down what she does on a workday morning. Mary's list looks like this: [0209] Call for cab. Done by using her TTY. [0210] Taking cab to work. Tell cab driver where to go. [0211] Stopping by the Starbucks® next to her office. Ordering coffee and a snack. [0212] Taking elevator to her office. [0213] Etc. [0214] In addition to the list above, Mary wants to add a few other common phrases to these activities that require speech in selected conversational groups. That way, when Mary starts off the day and opens this Conversational Group, most of the phrases that she will need for the morning will be on the display in front of her. (Refer to FIG. 10) This means that some phrases, like “Hello, my name is Mary” may end up in multiple Conversational Groupings. Note, in our example in FIG. 9, there are fifteen lines of displayed text. Mary decides that she will keep her custom Conversational Groupings to fifteen lines and instructs the software of her decision. Mary decides that the first phrase in her Workday Morning Conversational Grouping will be “Hello, I am Mary”. Mary follows these steps: [0215] Starting at the Top Conversational Grouping Mary chooses (double clicks on) Mary's Personal Information [0216] She then chooses Name [0217] She then chooses the phrase “Hello, my name is Mary” [0218] This can be shown in this fashion: [0219] Mary's Personal Information>Name>“Hello, my name is Mary” [0220] For the second phrase of her Conversational grouping she chooses “456 Main Street, Bethesda.” [0221] Mary's Personal Information>Work>“456 Main Street, Bethesda” [0222] Next Mary wants to have phrases ready for her stop at Starbucks®. She connects to the Internet and reaches the program web site. She does this instead of using the program CD, because the most current national restaurant chain menus are available from the website. She starts by choosing Food. This gives her the following choices: [0223] Breakfast [0224] Lunch [0225] Brunch [0226] Dinner [0227] Fast Food [0228] National Chains [0229] Drinks [0230] Etc. [0231] She chooses Drinks, which opens up these choices: [0232] Coffee [0233] Soft Drinks [0234] Juice [0235] Beer [0236] Mixed Drinks [0237] Wine [0238] Etc. [0239] She chooses Coffee, which opens up these choices: [0240] Generic [0241] Seattle's Best® [0242] Starbucks® [0243] Etc. [0244] She chooses Starbucks®, that opens up these choices: [0245] Coffee [0246] Coffee Drinks [0247] Pastry [0248] I want it my way [0249] Etc. [0250] She chooses Coffee, which opens up these choices: [0251] I would like a Venti Coffee please. [0252] I would like a Venti Decaf please. [0253] I would like a Venti Today's Special please. [0254] Etc. [0255] Mary chooses “I would like a Venti Coffee please.” So to sum up, Mary went through cascading Conversational Groups, which can be shown like this: [0256] Food>Drinks>Coffee>Starbucks®>Coffee>“I would like a Venti Coffee please. [0257] Mary always takes cream with her coffee, so she needs to ask them not to fill the cup up. [0258] She backs up a level [0259] Coffee<Starbucks® [0260] And then goes to: [0261] Starbucks>I want it my way>“Please leave a little room for cream” [0262] Mary instructs the software of the invention to link the two phrases she has just shown together, so when she chooses “I would like a Venti Coffee please,” eHello will say right after that, “Please leave a little room for cream.” [0263] In a similar fashion Mary chooses some more phrases for her Workday Morning Conversational Group: [0264] Coffee<Starbucks®>Pastry>“I would like a Low Fat Blueberry Muffin please” [0265] In case they are out of Blueberry Muffins she adds: [0266] “I would like a Low Fat Cranberry-Orange Muffin please.” [0267] There is an elevator between her and her workplace. In case she needs to ask someone to push the button for her floor, she adds: [0268] Transportation>Elevator>“Please press thirteenth floor” [0269] At this point Mary's Workday Morning Conversational looks like this: [0270] Hello, my name is Mary. [0271] 456 Main Street, Bethesda [0272] I would like a Venti coffee please. Please leave a little room for cream [0273] I would like a Low Fat Blueberry Muffin please. [0274] I would like a Low Fat Cranberry-Orange Muffin please. [0275] Please press thirteenth floor [0276] In a similar fashion, Mary continues to add to her Workday Morning Conversation Grouping. Mary continues to make her custom Workday Afternoon Conversational Group and Workday Evening Conversational Group. Mary works near a McDonalds® and often goes there for lunch. Since Mary does not know what she might want for lunch, she downloads the complete McDonald® conversational grouping, from the central website. [0277] Food>Fast Food>McDonalds® [0278] In this way Mary has the complete McDonalds® menu available to her. There is a Burger King® around the corner, so Mary downloads the complete Burger King® Conversational Grouping as well. In a similar fashion Mary makes more custom Conversational Groupings and adds pre-made Conversational Groupings. Mary has the option of adding a pre-made Conversational Group and deleting groups she does not want. In our example above of Starbucks®, Mary may have downloaded the entire Starbuck® Conversational Group with the exception of Coffee Drinks, which she does not want. [0279] Mary next starts choosing icons and their related phrases. The software of this invention displays a number of icons for Mary to choose. When she has chosen one, she is asked what phrase to associate with it. She first chooses a Smiley Face 901 . She chooses the phrase “Yes” to associate with the icon. She chooses seven more icons, and in a similar fashion, she associates the phrase “No” with the second icon, “Thanks” with the third icon, “You're Welcome” with the fourth, “My name is Miss Mary Alice Smith” with the fifth, “How much is that” with the sixth, “Help, please” with the seventh, and “Help, call 911” with the eighth. [0280] Lastly, Mary associates phrases she will be using often with a three-digit code, as in FIG. 8. [0281] This explanation takes longer to read than it will for a user to do. That is one of the advantages of using a graphical interface; it is faster and easier to use than text. Once Mary has arranged things to her liking, she connects her Pocket PC® to her PC with a standard cable and instructs the main program computer to download her custom Conversational Groupings to her Pocket PC. In this fashion, Mary can quickly and easily modify her Conversational Groups daily if she wants. [0282] The device shown in FIG. 9 is life sized. It weights approximately 8 ounces. It can be carried in a pocket, purse, pouch, or belt holster. Let's follow Mary as she begins her workday. [0283] Before Mary leaves home she turns her Pocket PC® on and starts the software. Her Pocket PC® has a pen-like pointing device, which she uses to point and click to make selections. Mary double clicks on Mary's Workday from the top conversational group and then double clicks on Morning. [0284] Mary's Workday>Morning [0285] That brings the following Conversational Group up on screen: [0286] Hello, my name is Mary. [0287] 456 Main Street, Bethesda [0288] I would like a Venti coffee please. Please leave a little room for cream [0289] I would like a Low Fat Blueberry Muffin please. [0290] I would like a Low Fat Cranberry-Orange Muffin please. [0291] Please press thirteenth floor [0292] Etc. [0293] Mary's cab comes. Mary gets in the cab and double clicks on “456 Main Street, Bethesda” and her Pocket PC® speaker speaks in Mary's chosen voice “456 Main Street, Bethesda.” Mary has taken less than two seconds to select the appropriate phrase, since she had taken the time to customize this Conversational Grouping earlier. Next stop is Starbucks®. When it is Mary's turn in line, she is ready. She has already highlighted “I would like a Venti Coffee please. As she moves up she clicks on the pound symbol that has her Pocket PC® say “I would like a Venti coffee please. Please leave a little room for cream.” Total time spent, one second. To Mary's dismay Starbucks® is out of both Low Fat Blueberry and Low Fat Cranberry-Orange Muffins. Fortunately Mary has the complete Starbucks® conversational groupings on her Pocket PC® minus the coffee drinks which she doesn't like. Mary clicks: [0294] Coffee<Starbucks®>Pastry>I would like a low fat lemon scone please. [0295] Although Mary wasn't prepared for asking for a low fat lemon scone, it takes her just four double clicks, maybe 4-6 seconds to have her device speak. After ordering Mary clicks: [0296] Top>Mary's Workday>Morning [0297] to display Mary's Workday Morning conversational group. [0298] This system is easy to use and very flexible. By spending some time up front, customizing Conversational Groupings, when in the real world a user's response time is very low. By making use of the phrase distribution system, users can be download the latest menu offerings at fast food restaurants, as well as having custom phrases made for their hotel address when out of town. [0299] Sample User Interface [0300] [0300]FIG. 10 is an illustration of a Sample User Interface on a Cassiopeia® Portable Computer by Casio®. This is just one possible interface and is shown for illustrative purposes only. To interact with this User Interface (UI) a user pushes on a particular area on the display with a stick, which is called point and click, or click. Double clicking is clicking on the same area two consecutive times. Activating means causing a phrase to be spoken by the device. [0301] This UI gives a user three different options to select a phrase to be spoken, icons, number code and clicking on phrases. It is designed to be easy, fast and convenient to use in any real world environments. The name of the conversational grouping that is displayed is shown at top 900 . Icons are shown along the right side 901 . These are activated by either double clicking on them or by single clicking to highlight, then-clicking on the # sign 902 to activate. Phrases are displayed on the left 903 . These phrases are activated by either double clicking or clicking once to highlight and clicking on # to activate. The third method to select a phrase is by clicking on the numbers on the bottom of the UI 902 . Digits that are clicked on are shown in the lower left box 904 . When the required three digit code is shown, clicking on # activates the phrase. [0302] Icons are used for frequently used phrases. Like every item on the UI they are user customizable. The top icon may be for the word “yes”, the money bag may be for “how much is this?”, the telephone may be for “call 911, medical emergency.” Users will choose which icons to display and what phrases to associate with those icons. As can be seen in FIG. 10 this device is small. This is a benefit in that it is easily carried and easily used out in the real world. The flip side is that there is not much display space. As can be seen in our example User Interface, there is only room for a few icons. However, a user may wish to memorize a three-digit code for additional frequently used phrases. Please see FIG. 8 for an example of this. [0303] The remainder of the UI is for showing conversational groupings. These are phrases that are grouped according to social and/or real world situations. For example, FIG. 7, shows a custom conversational grouping a user may require in the morning. The conversational groupings shown are changed throughout the day depending upon the user's requirements. [0304] Definitions [0305] Windows CE®. This is a version of Microsoft®'s Windows® operating system that is optimized for hand-held computing devices. [0306] Portable Devices or Mobile Device. This is a general term that refers to small computer devices. Although a notebook-sized computer is technically portable, as they typically weight six pounds or so, they do require a desktop or similar space to set up. For purposes of discussion, a Portable or Mobile Device, is a computing device that is smaller than a notebook-sized computer. [0307] Handheld Device. A handheld device is a portable computing device that is larger than a pocket device and smaller than a notebook computer. Typically a handheld device has a display with a resolution of 640×480 or greater. Some handheld devices have a keyboard. [0308] Handheld PC® is a handheld device which runs Windows CE® and contains a consistent package of integrated applications, wireless and wired connectivity options, and Win32 APIs for developers. Some examples of Handheld PC® are Husky Technology Field Explorer 21, Casio PA-2400, Sharp Mobilon TriPad PV-6000, Hewlett-Packard Jornada 820, NEC Computers Inc. MobilePro 880. [0309] Pocket Device. A pocket device is a portable computing device that is small enough to fit into a jacket pocket. [0310] Pocket PC® is a pocket device which runs Microsoft Windows CE®, has at least a quarter VGA display (320×240) and contains a consistent package of integrated applications, wireless and wired connectivity options, and Win32 APIs for developers. Some examples of PocketPC® are Cassio E-115, E-125, EM500, Compaq iPAQ, Hewlet Packard hp jornada 548 and 545, Symbol PPT 2700. [0311] The foregoing description of the preferred embodiments of the invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and 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 method and system for producing audio speech for a speech-impaired user and/or a user desiring audio speech in a language a user is unfamiliar with. Phrases and sentences are spoken in different voices, converted to Digital Speech Audio Files (DSAF) and stored on a server. These DSAF are then organized into Social Groupings. A user is granted access to this server. These DSAF organized into Social Groupings may also be distributed on physical digital media. A user moves desired DSAF either individually or in Social Groupings onto client machine. If a user requires phrases or sentences not offered, a request is issued, and subsequently the requested phrases or sentences are distributed to user and moved to client machine. A user organizes the DSAF on the client machine by modifying existing Social Groupings, creating new Social Groupings and/or assigning a unique code to selected phrases and sentences. The DSAF arranged in Social Groupings are moved to a portable device, if not already on one. A user identifies and plays the DSAF as desired to produce speech.

RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/406,414 filed Oct. 25, 2010, and is a continuation-in-part of U.S. patent application Ser. No. 13/069,292 filed Mar. 22, 2011 (which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/316,070 filed Mar. 22, 2010), which is a continuation-in-part of U.S. patent application Ser. No. 12/911,445 filed Oct. 25, 2010 (now abandoned), which is a continuation of U.S. patent application Ser. No. 12/106,968 filed Apr. 21, 2008 (now U.S. Pat. No. 7,822,896 and which claims the benefit of U.S. Provisional Application Ser. No. 60/950,040 filed Jul. 16, 2007), which is a continuation-in-part of U.S. patent application Ser. No. 11/801,127 filed May 7, 2007 (now abandoned), which is a continuation of U.S. patent application Ser. No. 11/296,134 filed Dec. 6, 2005 (now U.S. Pat. No. 7,216,191), which is a continuation-in-part of U.S. patent application Ser. No. 11/043,296 filed Jan. 25, 2005 (now abandoned), which is a continuation-in-part of U.S. patent application Ser. No. 10/071,870 filed Feb. 8, 2002 (now U.S. Pat. No. 6,892,265 and which claims the benefit of U.S. Provisional Application Ser. No. 60/269,129 filed Feb. 14, 2001). The foregoing disclosures are incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates generally to methods and apparatus for driving solenoids, and more particularly to a configurable connectorized apparatus for driving a solenoid coil. BACKGROUND [0003] Solenoids are widely used throughout the world. Thus solenoids actuate relays or contactors that apply power to the starter motor of most cars. Solenoids actuate the lock mechanism in most keyless door systems. Most automatic valves, whether pneumatic or fluidic, employ solenoids to actuate or pilot the valve. Solenoids are found in factories, buildings, cars and homes. [0004] FIG. 1 depicts a generic solenoid 10 showing its principal constituent parts. The two leadwires, 2 , convey electrical current to the solenoid coil 3 which generates a magnetic field. The magnetic circuit of said solenoid 10 includes the metal case 4 and the air gap 6 . The armature 5 is influenced by the magnetic field and a force will attempt to move or hold the armature 5 in the direction of the hardstop 8 . When said armature 5 contacts and remains in contact with said hardstop 8 , it is said to be sealed. Various features are often added to said armature 5 such as the hole 7 in order to attach a mechanism to the armature 5 and thereby complete the mechanical linkage to the solenoid mechanism. Not shown is the return mechanism, such as a spring, which tends to return said solenoid 10 to its open position when electrical current is removed from said solenoid 10 . [0005] Solenoids transduce the flow of electrical current into motion via force on the moving portion of the solenoid called the armature. The armature of a solenoid may be connected to various mechanisms, thus in a relay, the armature motion opens or closes electrical contacts whereas in a solenoid-operated valve, the armature is often directly connected to one side of a valve seal. In larger valves, the solenoid operates a smaller so-called pilot valve that employs some fluidic or pneumatic amplification, but the basic operation of the valve is initiated by the solenoid action. [0006] Therefore, solenoids are essential components in a wide range of mechanisms that perform among other things, electrical switching, latching, braking, clamping, valving, diverting or connecting. [0007] The most common method of actuating solenoids involves applying a constant voltage to the coil, whether AC or DC. The voltage causes a current to flow in the coil and a consequent magnetic field is generated which puts force on the solenoid armature and moves the mechanism to which the solenoid is attached. However, as described in detail below, there are significant challenges associated with driving solenoids in an energy efficient manner with circuitry that does not itself create further problems. [0008] FIGS. 2-4 provide examples of circuits used for driving solenoids. FIG. 2 depicts a common prior art transistor solenoid drive circuit including transistor 11 which is capable of conducting electrical current in response to a signal on its input. Said electrical current will flow through solenoid 10 . When said transistor 11 is caused to stop conducting in response to a signal on its input, a flyback diode 14 conducts electrical current in order to prevent the inductive component of said solenoid 10 from increasing the voltage seen by said transistor 11 and possibly destroying said transistor 11 . When the energy in said solenoid 10 has been exhausted by the recirculation process, said current ceases and said solenoid 10 is thus de-energized. [0009] FIG. 3 depicts a solenoid driver integrated circuit 12 such as is commercially available from a number of manufacturers and employing pulse width modulation (PWM) of the supply voltage in order to reduce the holding current to the solenoid 10 . Connected to said solenoid driver 12 is said solenoid 10 as well as two of the commonly required external components, a flyback diode 14 and a series-connected diode 13 intended to both prevent damage to said driver integrated circuit 12 and to somewhat reduce electrical radiation from the PWM switching transients. Said solenoid driver integrated circuit 12 is fixed configuration and cannot be reconfigured for other purposes such as measuring or producing voltages or currents other than required for the narrow solenoid drive task at hand. [0010] FIG. 4 depicts a typical prior art fixed configuration sinking output module 17 capable of driving solenoid 10 . As is typical for the prior art, said output module 17 does not provide power to drive said solenoid 10 but instead relies upon connecting and disconnecting power provided by external device power supply 18 . In addition, as is customary for said fixed-configuration output modules 17 , terminal blocks 19 are employed to effect the wiring to said solenoid 10 . In addition, as is customary for said output modules, a protective flyback diode 14 is installed to reduce voltages produced by said solenoid 10 during the de-energization process. [0011] As is widely known to those skilled in the art of solenoid-driven mechanism design, there is a delicate balance between providing sufficient solenoid force at a desired distance of travel and generating excessive energy consumption and heating in the solenoid coil. The amount of electrical current required to move the solenoid to its closed position is high compared to the electrical current required to keep the solenoid closed—or sealed as is the term of art. Thus a solenoid that is to remain sealed for a long period of time tends to become hot and consume a large amount of energy compared to what is needed just to hold the solenoid sealed. The delicate balance for the solenoid-driven mechanism designer is to build a solenoid that will reliably move a given distance to the sealed position while at the same time not consuming excessive electrical power or overheating despite constant application of power to the solenoid coil. [0012] This basic design challenge of the solenoid underscores the problem that is to be solved by this invention, and therefore a more detailed description of the cause of this design challenge is justified in order to explain the merits of this invention. [0013] Whereas the solenoid transduces the flow of electrical current to force on the armature, said force is not a constant function of electrical current. When the solenoid is sealed, there is essentially no air gap in the magnetic circuit, thus the magnetic flux is relatively high at a given electrical current. However, when the solenoid is fully open, there exists an air gap in the magnetic circuit that significantly increases the electrical reluctance of the circuit, said reluctance being the ratio of magnetomotive force (MMF) to magnetic flux developed. Thus at said given electrical current, the force on the fully open armature can be significantly lower than when the armature is in the sealed position. In order to move the armature reliably, therefore, it is necessary to supply more electrical current than is required when the solenoid is sealed. To make matters worse, the requirement for high current to seal the solenoid only lasts for a fraction of a second whereas the solenoid is often left in its conducting, sealed state indefinitely. Energy is being wasted. [0014] Those skilled in the art long ago realized that, for a given solenoid current, the force on the armature increases as the armature moves closer to its sealed or closed position because reluctance decreases with the shorter air gap. These same persons reasoned that by varying the current or voltage to the solenoid, they could provide an initially higher force to seal the solenoid and subsequently reduce the current or voltage in order to hold the solenoid sealed because the force exerted upon a sealed solenoid armature is much higher than the force on an open solenoid given the same electrical current or voltage. By employing this strategy of varying the current or voltage, it is possible to reduce the heating of the solenoid coil while providing the required high force to close the solenoid. [0015] In U.S. Pat. No. 7,262,950 B2 (“Suzuki”), Suzuki teaches that building a current control circuit can allow cutting back the current to the relay coil after the relay has closed. Unfortunately, the circuit of Suzuki requires that a series-wired transistor throttle the current to the relay coil thus creating heat and reducing the possible energy savings considerably. Thus Suzuki's invention does somewhat reduce solenoid heating but by moving some of the heat generation to a transistor. For example, if Suzuki reduced the holding solenoid current to ½ of the initial pull-in current, then the system of Suzuki would see solenoid energy use go down to ¼ of the previous level. Unfortunately, another ¼ of said energy is burned up in ohmic losses in the transistor. In addition, Suzuki does not mention a strategy for dealing with the effect of the relay coil inductance during relay turn-off. It is well understood in the art that employing a transistor to remove power from an inductor will result in a large voltage swing that in general must be mitigated by inserting a path for current to flow thus avoiding a dangerous increase in circuit voltage. Generally, a diode is employed that will allow the relay coil current to circulate during turn-off. [0016] Others have attempted to avoid wasting half of the energy reduction. Others have reasoned that employing pulse width modulation (PWM) of the solenoid voltage could reduce the losses in the transistor via well-understood power switching technology in which the transistor is rapidly turned on and off, largely avoiding its linear region. This strategy works well for inductive circuits wherein little current initially flows during the closing of the transistor. Fortunately, a solenoid is highly inductive, thus PWM works well. Unfortunately, however, PWM can easily generate disruptive electrical radiation unless special care is taken. In an industrial control system application it is almost unthinkable to place restrictions on the user of a solenoid. [0017] Then too, a class of integrated circuits, such as Texas Instruments DRV102 PWM Valve/Solenoid Driver, has aimed to produce a fixed and dedicated electrical circuit capable of initially driving the solenoid with full voltage and consequently full current and subsequently reducing said current by performing PWM of the power signal to the solenoid. Unfortunately, said integrated circuits can produce undesirable electrical interference as described earlier. For example, an application note for the Texas Instruments DRV102 states, “The PWM switching voltages and currents can cause electromagnetic radiation.” The note further suggests that determining the location of noise reducing components “may defy logic”, i.e. may be difficult to predict and require repetitive empirical testing. In addition, such integrated circuits usually require the addition of a number of external components and are fixed configuration: the connector to which the solenoid is attached can only drive a solenoid. The present invention as explained below provides additional applications and flexibility that is not available using these prior art devices. [0018] The prior art has not adequately addressed a significant design challenge in solenoid driving: how to determine if a solenoid is sealed. A solenoid can fail to reach or stay at its closed or sealed position upon the application of electrical current for a number of reasons. The solenoid may be jammed and unable to initially move in either direction. The solenoid coil may be open or not electrically continuous and therefore incapable of generating the required magnetic field. The solenoid coil may be shorted. The solenoid may be exposed to vibration that puts a sufficient force on the solenoid to unseal it. Or, there could be a momentary loss of electrical current that results in the solenoid holding force being reduced briefly. Or, the current applied to the solenoid coil might be slightly less than required to reliably hold the solenoid armature sealed under all physical variations such as ambient temperature. The prior art only teaches a single solution to this dilemma of determining the solenoid state, and that is to cause the solenoid to close an electrical connection when it is sealed. FIG. 5 depicts the prior art apparatus for determining the state of the solenoid, whether sealed or open. In this prior art system, the controller 90 commands a solenoid coil 91 to close. After the solenoid 91 has been given sufficient time to seal, the controller 90 then senses the state of the auxiliary contact 92 which is mechanically linked to the solenoid mechanism. Based upon the state of said auxiliary contact 92 , said controller 90 can deduce the state of the solenoid 91 . However, if the solenoid 10 is not a relay, then said solenoid 10 must be mechanically connected to said auxiliary contact 92 , such connection being problematic and costly. Even in the case where the solenoid is part of a relay, this strategy requires using one set of contacts for this monitoring process. Additional electrical circuits are required to monitor this extra contact, and for systems employing reduced holding current, the actuation sequence must be repeated. In the case where the solenoid is not a part of a relay, then a set of contacts must be added to the solenoid mechanism. This requirement is prohibitive except for the most critical solenoid systems. SUMMARY OF THE INVENTION [0019] The present invention provides a configurable connectorized method and apparatus for driving a solenoid coil, capable of providing a sufficiently high force to move the solenoid from its fully open position to its sealed position. It can also reduce the energy consumed and the heating of the solenoid coil when the solenoid is sealed. The present invention reduces the energy without continuous losses from a series throttling transistor or resistor. The invention facilitates detection of a solenoid coil which is open or shorted, and can reduce the current on a solenoid for which the armature is jammed in order to reduce the consequential overheating of the coil. The present invention eliminates the requirement to use PWM as the drive method, and handles coil turn-off behavior without the need for additional components such as diodes. The present invention simplifies connections to one or more relays or solenoids without the requirement for external power supplies. The present invention allows determination of whether a solenoid is sealed without the need for auxiliary electrical contacts, and can use information about the solenoid unsealed state to essentially instantaneously increase the force on the solenoid armature to cause the armature to return to its sealed position before the armature has moved significantly. [0020] The present invention extends the teachings of U.S. Pat. Nos. 6,892,265, 7,216,191 and 7,822,896 and U.S. patent application Ser. No. 13/069,292, published as Patent Appl. Publ. No. US 2011 / 0231176 . In the previous inventions, a configurable connectorized system is described in which any connector pin of such a system may be configured for a wide variety of electrical functions, such as measuring a voltage, producing a voltage, measuring a current, producing a current, producing various power levels or even handling frequency information such as serial communication data. [0021] A single version product built using these teachings has solved numerous industrial controls problems. When compared with traditional industrial control input/output modules, the configurable, connectorized input/output module dramatically reduces the number of additional components required such as power supplies and terminal blocks. The configurable, connectorized input/output system eliminates the need for many different fixed-configuration modules by virtue of its ability to change the electrical configuration of its connector pins. [0022] The present invention enables the pin configuration of the input/output module to be changed during normal operation, thus if a solenoid is connected between two such pins, the voltage across the solenoid may be changed without any added components or without the required use of PWM. Because the present invention enables the pin configuration to be changed from one power supply to another or varying the voltage level of any said multiple power supplies, the invention allows high efficiency power supplies to be used. Therefore, no throttling or PWM is required to reduce the voltage across the solenoid, although nothing precludes the use of PWM in the present invention should it, for some reason, be determined to be beneficial. In addition, the present invention also provides two ways to handle the inductive current at turn-off. First, the configurable connectorized module can throttle the current gradually while holding the coil voltage within an acceptable level. Second, the first of one of the solenoid's two pins may be again reconfigured to the same voltage as the second pin thus connecting both sides of the solenoid coil to the same power supply, either high side or low side. In both ways, the effect of the inductance of the coil during circuit turnoff is addressed, and no additional components are required to provide for safe circuit operation. [0023] In addition, because the present invention provides for connecting other sensing and sourcing circuit elements to the connector pin, it is possible to determine whether the solenoid is sealed. Said determination is based upon the fact that the electrical inductance of the solenoid is inversely related to the electrical reluctance and said reluctance decreases as the solenoid air gap goes to zero. Said determination is achieved by imposing either a periodic or step change to voltage across the solenoid and measuring the resulting periodic or step change in current. Said resulting current is a function of solenoid inductance. Or, alternatively, said determination may be achieved by making either a step change or a periodic change to the current through the solenoid and measuring the resulting change in voltage, although the preferred embodiment is the former method of determination. Said determination includes whether the solenoid is sealed, opening or open. In addition, in the case where the solenoid becomes unintentionally unsealed, the method and apparatus of the present invention is capable of essentially simultaneously increasing the solenoid current to reseal the solenoid, thus preventing unintended opening of the solenoid. Said resealing can be effected without any additional apparatus than is found in the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0024] FIG. 1 is a depiction of a generic solenoid showing its principal constituent parts. [0025] FIG. 2 is a common prior art circuit apparatus for driving a solenoid coil, and in particular shows the required fly-back diode. [0026] FIG. 3 is a common prior art circuit apparatus for driving a solenoid coil that uses pulse width modulation (PWM) and in particular shows the required series-wired diode as well as the additional fly-back diode. [0027] FIG. 4 depicts a prior art circuit common to a programmable logic controller or industrial fixed-configuration output module. [0028] FIG. 5 depicts the prior art apparatus for detecting the unsealed state of a solenoid. [0029] FIG. 6 depicts the configurable apparatus of the present invention. [0030] FIG. 7 depicts the connection of a relay or solenoid coil to a configurable connectorized module of the present invention. [0031] FIGS. 8A , 8 B and 8 C depict the command, voltage and current wave forms, respectively, of the present invention when actively snubbing the decaying solenoid currents to zero. [0032] FIGS. 9A , 9 B and 9 C depict the command, voltage and current wave forms, respectively, of the present invention when allowing decaying solenoid currents to flow to zero. [0033] FIG. 10 depicts a model of the constituent resistive and inductive components of the solenoid for the purpose of describing the method and apparatus of the present invention for determining the unsealed state of a solenoid. [0034] FIGS. 11A , 11 B, 11 C and 11 D depict the voltage and current waveforms, employed to measure the inductance of the solenoid and thereby determine the unsealed state of said solenoid, of the present invention. [0035] FIGS. 12A and 12B depict voltage and current waveforms for an alternative method of the present invention for solenoid state determination. [0036] FIG. 13 is an example of an ASIC configured as a pin driver interface apparatus, according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0037] FIG. 6 depicts a functional block diagram of the configurable connectorized input/output module 15 of the present invention. Included inside said module 15 of the preferred embodiment is a microprocessor 80 which is capable of directing any of a plurality of signals to one or more pins 16 which are subsequently to be connected to various sensors and actuators such as solenoid, but by no means limited to solenoids. In particular, said configurable connectorized input/output module 15 contains one or more power supplies 81 which may be routed in the same manner as other of the plurality of signals via switching means 82 such as R 5 or R 6 and connect to one or more connector pins 16 . When a solenoid is connected between two such pins 16 , the configurable connectorized input/output module 15 can produce one of a plurality of power levels to said solenoid thereby adjusting the current flowing through the solenoid without the need for PWM. [0038] The configurable input/output module 15 may contain any number of interconnection apparatus 83 . Each interconnection apparatus 83 is connected to one device connector 16 and optionally through an internal cross point switch to another interconnection apparatus. (See FIG. 13 and related description.) FIG. 6 is highly stylized and is intended to convey the essence of the module of the present invention. [0039] FIG. 7 depicts the configurable connectorized input/output module 15 of the present invention when connected to a solenoid 10 . In this configuration, said module 15 has been configured by the microprocessor 80 to route a plurality of power levels from power supplies 81 to pins 1 and 2 of said module 15 . Any of the 15 pins shown in FIG. 7 could have been configured for this function, unlike prior art fixed-configuration output modules. Unlike the prior art fixed-configuration output module, where an external device power supply was required, none is required by the present invention and none is shown in FIG. 7 . Also unlike the prior art fixed-configuration output module where a flyback diode is required to protect the output module, none is required by the present invention and thus none is shown. The configurable connectorized input/output module 15 of the present invention is thus able to cause one of a plurality of voltages to be applied to the connected solenoid 10 thus effecting the goals of the present invention. [0040] FIGS. 8A , 8 B and 8 C depict the voltage and current waveforms resulting from the actuation of the solenoid 10 using a snubbing turnoff method and apparatus, and shown as Solenoid Drive Signal in FIG. 8A . There are nine phases to the voltage waveform which we will now describe. Each phase is numbered 21 through 29 in FIG. 8B . [0041] In Phase 21 , the solenoid voltage is zero which is the idle state of the solenoid. The solenoid is unpowered and ready to be actuated. [0042] In Phase 22 , in response to the solenoid drive signal becoming true, 30 , the configurable connectorized input/output module 15 connects the actuation-level voltage to the solenoid 10 . In this preferred embodiment, said activation-level voltage is 24V. In response to the imposed voltage, current in the solenoid coil rapidly increases, 40 , and the solenoid moves smartly because the imposed voltage is preferably higher than the sustainable steady state coil voltage. However by varying the duration of phase 23 , it is possible to control the solenoid actuation force. [0043] In Phase 23 , the configurable connectorized input/output module 15 maintains the pull-in-level voltage on the solenoid coil and the coil current moves asymptotically to steady state, 41 . The length of the Phase 23 portion is sized such that said solenoid current may not reach steady state in order to control the solenoid actuation force. At the end of phase 41 , the solenoid is preferentially in its closed or sealed position. [0044] In Phase 24 , the configurable connectorized input/output module 15 essentially simultaneously disconnects the actuation-level voltage from the solenoid and connects the sustain-level voltage to the solenoid. Alternatively, the voltage level of a single power supply can be varied to achieve the same goal. The sustain-level voltage is chosen to provide ample holding force for the solenoid, whereas said sustain-level voltage might not be sufficient to reliably pull in the solenoid under all conditions. Said sustain-level voltage can preferentially be adjusted by the microprocessor 80 . As Phase 24 begins, the solenoid coil current 42 begins to decrease in response to the lower applied voltage. Said solenoid coil current decreases to a steady state 43 after some time period which is a function of the solenoid electrical characteristics. [0045] In Phase 25 , the sustain-level voltage is maintained on the solenoid in order to keep the solenoid sealed. Phase 25 is maintained as long as required by the control system. This time can range from milliseconds to months or longer. [0046] In Phase 26 , the process is begun to remove power from the solenoid in response to the solenoid drive signal becoming false, 31 . The configurable solenoid drive circuit cannot simply open its drive transistors to the solenoid because the inductance of the solenoid coil—which makes rapid reduction in current infeasible—would cause the voltage at the configurable connectorized input/output module pin 16 to become very negative with respect to ground and likely damage or destroy the switching means 82 . If the solenoid coil is equipped with a so-called flyback diode, then said solenoid current is provided a path while the coil energy is dissipated. If, however, there is no flyback diode, then the coil voltage will cross zero volts and become negative. The configurable connectorized input/output module 15 of the present invention is therefore configured to begin to throttle the coil current and clamp the coil voltage to a value, which in the preferred embodiment is approximately −5V with respect to ground. [0047] In Phase 27 , the throttling process continues until the voltage that the coil is capable of sourcing falls to less than the clamped voltage. During Phase 27 , the solenoid coil current 44 decreases linearly. [0048] In Phase 28 , the configurable connectorized input/output module 15 stops actively throttling the solenoid coil current and instead provides a fixed transistor gate drive thus dissipating the remaining energy from the solenoid coil. The solenoid current, 45 , decays exponentially to zero during Phase 28 , and the solenoid coil returns to its idle state. [0049] In Phase 29 , the solenoid coil is in the same state as it was in Phase 21 : the coil is quiescent, the solenoid is not engaged and the solenoid is again ready to be actuated. The solenoid coil current, 46 , is also zero. [0050] With reference to FIGS. 6 & 7 , the interface apparatus 84 may be configured to connect one of a plurality of power supplies to the device connector 16 to which the solenoid 10 is connected. For example, switching means 82 can initially be caused to connect a 24VDC power supply to said device connector 16 in order to achieve the solenoid pull-in phase. Likewise, said interface apparatus 84 may then be caused to connect a 5VDC power supply to said device connector 16 in order to achieve the solenoid sustaining phase. [0051] FIGS. 9A , 9 B and 9 C are very similar to FIGS. 8A , 8 B and 8 C with the exception that rather than throttling the solenoid current, the two pins of the configurable connectorized input/output module 15 which are connected to the solenoid 10 are set to the same voltage, either high-side or low-side. In so doing, the solenoid current flows through said module 15 until the solenoid current is exhausted. Thus phase 27 in FIG. 9B remains at zero volts, not −5 volts as in FIG. 8B . And the current in FIG. 9C decreases asymptotically to zero in phase 46 . [0052] In the context of the present invention, determining the state of the solenoid, whether sealed, opening or fully open is achieved by measuring the inductance of the solenoid coil, since said inductance is inversely proportional to reluctance which is itself a function of the solenoid air gap: reluctance decreases as air gap decreases and then further decreases when the solenoid fully seals and the air gap is essentially eliminated. The present invention provides a number of methods and a number of apparatuses to measure said inductance. Two methods and two apparatuses will be described, but are intended to be for illustrative purposes only. Simpler or more appropriate methods using other features of the present invention are possible but this description is intended to convey the essence of the invention. [0053] FIG. 10 depicts a common electrical circuit model used to describe the inductance measurement of the present invention. Specifically, the solenoid 10 has been broken down into two constituent parts. Its resistive component 95 is series-connected to its inductive component 96 . This model will facilitate the description of the inductance measurement system. [0054] FIG. 11A depicts the DC voltage across a solenoid. Said voltage may be any appropriate value greater than or equal to zero volts. FIG. 11B depicts the resulting DC current given the applied voltage depicted in FIG. 11A , said resulting DC current being greater than or equal to zero. FIG. 11C depicts a sinusoidal voltage signal of suitable frequency imposed upon the DC voltage signal of FIG. 11A , said sinusoidal voltage being a sufficiently small percentage of the DC voltage as not to affect the operation of the solenoid but sufficiently large to generate a measurable current in said solenoid 10 . Said sinusoidal voltage signal is established by making small changes to the voltage setpoint of any of the multiple power supplies 81 connected to the configurable connectorized input/output module 15 of the present invention. Said sinusoidal voltage signal will cause a variation in the DC current signal of FIG. 11B that is also essentially sinusoidal. Said variation in the DC current signal is shown in FIG. 11D . The phase of the signal of FIG. 11D with respect to the sinusoidal voltage signal of FIG. 11C will be a function of the relative magnitudes of the two constituent elements depicted in FIG. 10 , the resistive 95 and inductive 96 components of said solenoid 10 . Specifically, if the resistive element 95 of FIG. 10 were to be large and the inductive component 96 of FIG. 10 were to be small, then the phase of the current signal of FIG. 11D with respect to the voltage signal of FIG. 11C will be small and closer to 0 degrees than 90 degrees. If, however, the resistive component 95 of FIG. 10 were to be small and the inductive component 96 of FIG. 10 were to be large, then the phase of the current signal of FIG. 11D with respect to the voltage signal of FIG. 11C will be large and closer to 90 degrees than 0 degrees. Using well known methods of signal processing wherein quadrature components of the current signal can be extracted, we can measure the inductive component of the solenoid 10 . [0055] Alternative methods and apparatuses may be used for the inductance measurements, such as periodic square wave excitation rather than periodic sine wave excitation with similar results and perhaps a simpler and more effective embodiment. Furthermore, step changes in voltage or current and the subsequent measurement of the response in current or voltage can provide similar inductance measurements in an embodiment that may be more appropriate for the electronic circuits employed. [0056] An alternative method for solenoid state determination relies upon observation of step responses rather than the phase and magnitude of response to periodic excitation. FIG. 12A depicts solenoid voltage for a typical energization and de-energization sequence, with state query pulses used to determine whether the solenoid is sealed. The magnitude or polarity, and the duration of these query pulses are designed to avoid altering the state of the solenoid. FIG. 12B depicts the solenoid current response to this sequence in FIG. 12A and its query pulses. The three voltages imposed across the relay in this method would, in a preferred embodiment, be the same levels used for energization, holding, and de-energization, although this is not a critical aspect of the present invention. This method will now be described in detail, in the order of events or phases in the depicted sequence. [0057] Initially, the solenoid is de-energized, with zero current and voltage. In that state, query pulses of sufficiently small amplitude and duration can be applied to produce the current response 50 without moving the solenoid armature. By sampling said current response at its known peak, at the end of the query pulse, the solenoid inductance can be inferred with one sample provided the query pulse duration is short in comparison to the L/R time-constant of the solenoid in its sealed or unsealed state, or in between states. As described previously, this inductance indicates the solenoid state, an object of the invention. [0058] At some time, the solenoid is energized, producing the current response 51 and one of the current responses 52 or 53 , depending upon whether the solenoid armature moves or not. Because the inductance can be measured for the de-energized state, and because responses 51 and 53 are both part of a simple, real exponential determined by that known inductance and the resistance known by other means, this non-moving pin response can be readily distinguished from the response pair 51 and 52 which exhibit markedly different trajectories. This distinction may be made by sampling the current at times along the response whose time-separation is short in comparison to the L/R time-constant, permitting a simple computation by microprocessor 80 to detect the trajectory departure 52 from the simple, real exponential, which departure indicates the desired motion of the solenoid armature. This method represents an improvement over an earlier invention, U.S. Pat. No. 3,946,285, which relies upon detection of the cusp at the end of response phase 52 , because it does not rely upon double differentiation or existence of the cusp which can be softened or eliminated if the solenoid armature is not abruptly stopped at the end of its energization travel. [0059] After successful energization, the solenoid voltage is reduced to its holding level, producing current response 54 , eventually settling to the low-power holding current at the onset of current response 55 . [0060] During energization, query pulses are applied at whatever rate is appropriate for the application, producing current response 55 . While this is similar to current response 50 , the current change relative to the step amplitude is smaller because of the much higher inductance of the solenoid in its sealed state. Again, as for current response 50 , a single sample at the response 55 peak can be used to infer solenoid inductance and hence its sealed or unsealed state. Because the inductance in the unsealed state is several times smaller than the sealed state inductance, the amplitude of the current response 55 , relative to its holding current baseline, readily distinguishes the solenoid states. [0061] At some time, the solenoid is de-energized, producing the current response 56 and one of the current responses 57 or 58 , depending upon whether the solenoid armature moves or not. These conditions can be distinguished by the same criteria mentioned above for detection of successful energization, except to detect successful de-energization. [0062] Finally, the de-energized starting state is reached, with query pulses producing current response 59 at whatever rate is appropriate for the application. [0063] It should be noted that the query pulses indicate the solenoid armature position independently of whether armature motion is detected by distinguishing current trajectories. For many applications, the query pulses alone would suffice to detect solenoid failures. However, the motion detection provides an earlier indication of success or failure, during a time when the query pulses cannot be applied. Such earlier detection may be important in applications where other system actions should soon follow a solenoid state change, but only if that change occurs as commanded. [0064] Said measurement of inductance can be pei formed constantly by the configurable, connectorized system of the present invention. Because the measurement does not affect operation of the solenoid, it is preferable that the measurement be first made when the solenoid is not energized with a DC voltage above zero. Said first measurement is then used as the baseline inductance of the solenoid. [0065] While the solenoid is first commanded to seal by the action of the configurable connectorized input/output module 15 , said measurement of inductance continues to be made. When the solenoid is sealed, the sealed measured inductance will be higher than said first baseline measurement of inductance because of the previously described electrical characteristics of a solenoid. Said sealed measured inductance is stored by the microprocessor 80 of the configurable connectorized input/output module 15 and is subsequently used to determine the state of the solenoid, whether sealed, opening or open. [0066] Said inductance measurement is continuously performed during the time that the solenoid is intended to remain sealed and during which time the solenoid voltage is at its lower holding level 25 . If, for any reason, said solenoid 10 becomes unsealed, its inductance will consequently decrease. Said inductance measurement will detect this decrease in inductance. Essentially simultaneously, the configurable connectorized input/output module 15 will increase the solenoid voltage to its pull-in value 23 in order to reseal the solenoid 10 . In so doing, the present invention can prevent the solenoid armature 5 from moving far enough to affect the mechanical state of the mechanism to which the solenoid 10 is connected. After the solenoid 10 is resealed, the configurable connectorized input/output module 15 may then again lower the applied solenoid voltage to the hold-in value 25 in order to again reduce the energy consumed by the solenoid 10 . The method and apparatus of the present invention may optionally slightly increase the applied solenoid voltage to slightly increase the solenoid holding force to compensate for the effect that led to the unsealing of the solenoid. [0067] The snubbing turnoff method as described with reference to FIGS. 8A-8C above, the variations described with reference to FIGS. 9A-9C , the method for determining the state of a solenoid as described with reference to FIGS. 10 and 11 A- 11 D and variations thereof may all be implemented with the configurable, connectorized input/output module of the present invention and a computer program. The computer program may be stored in memory in the module and executed by the microprocessor in the module. Alternatively, the program may be stored externally to the module—in a control system for example—and instructions are sent to the microprocessor in the module for running the processes. In a further alternative, computer programs for some of the processes of the present invention may be stored in memory on the module, and some external to the module—in memory in the control system, for example. An example of a system controller 85 connected to the module 15 is shown in FIG. 7 . The connection between the system controller and the module may be a standard cable or a network connection (for example, Ethernet). The connection may be a backplane connector—for example, the module may be plugged into the backplane of a PLC or an embedded controller. The connection may also be a wireless connection. Without departing from the teaching of the present invention, a configurable, connectorized input/output module may: act as a so-called embedded controller; be a circuit board which is part of a larger system; or function as the system controller by itself. [0068] The interface apparatus 84 , including interconnection apparatus 83 such as those illustrated in FIG. 6 , may be configured as an integrated circuit (IC). The IC is repeated within the I/O module 15 for each device connector 16 . Thus, if there are 25 device connectors 16 , then 25 ICs would be employed. The module 15 can contain any number of ICs, just as any module may contain any number of device connectors 16 . Another embodiment may employ a different IC architecture in which multiple device connectors 16 are handled in each IC or multiple ICs are used to handle one or more device connectors. The result of using an IC is a dramatic reduction in the size and cost of building a module 15 by virtue of the miniaturization afforded by modern semiconductor processes. [0069] FIG. 13 is a block diagram of an integrated circuit capable of realizing the interface apparatus, 84 . The integrated circuit 198 has been specifically designed to serve the role of the interconnection apparatus, thus it may be referred to as an Application Specific Integrated Circuit (ASIC). This ASIC is specifically designed to provide the functionality of the interconnection apparatus 83 . At some point in the future, such an ASIC could become a standard product from an integrated circuit vendor. Therefore the term ASIC, as used herein, includes a standard integrated circuit designed to function as the interface apparatus. Furthermore, the term integrated circuit (IC), as it is used herein is intended to cover the following range of devices: ASICs, hybrid ICs, low temperature co-fired ceramic (LTCC) hybrid ICs, multi-chip modules (MCMs) and system in a package (SiP) devices. Hybrid ICs are miniaturized electronic circuits that provide the same functionality as a (monolithic) IC. MCMs comprise at least two ICs; the interface apparatus of the present invention may be realized by a MGM where the required functionalities are divided between multiple ICs. A SiP, also known as a Chip Stack MCM is a number of ICs enclosed in a single package or module. A SiP can be utilized in the current invention similarly to a MCM. In theory, programmable logic devices might be used to realize the interface apparatus of the present invention. However, currently available programmable logic devices, such as field programmable gate arrays (FPGAs), have a number of functional limitations that make their use undesirable—for example an FPGA cannot route power or ground to a given pin. Should FPGAs be extended to overcome these functional limitations then these improved FPGAs may be used as components to realize the interface apparatus 84 . [0070] FIG. 13 depicts a block diagram of a pin driver ASIC 198 . When connected to the microprocessor 80 by a serial communication bus 206 such as an SPI interface, the microprocessor 80 of FIGS. 6 & 7 can command the ASIC 198 to perform the functions of the circuits of interconnection apparatus 83 . Although the circuitry of FIG. 13 appears different from the interconnection apparatus 83 , the ASIC 198 is capable of performing the same or similar required functions. Whereas FIG. 6 is a somewhat idealized diagram intended to convey the essence of the module of the invention, FIG. 13 contains more of the circuit elements that one would place inside an ASIC. Nonetheless, FIG. 13 implements all the circuit elements of FIG. 6 . For example, FIG. 6 shows a digital-to-analog converter (D/A or DAC) connectable to the device communication connector 16 . In FIG. 13 , the digital-to-analog converter 226 is connected to the output pin 208 via the switch 220 . The present invention also includes other circuit arrangements for an ASIC 198 for the same or similar purpose. Those skilled in the art will know how to design various such circuitry, and these are to be included in the present invention. [0071] Exemplary features of the ASIC of FIG. 13 will now be briefly described. Power may be applied to pin 208 by closing high current switch 222 b and setting the supply selector 227 to any of the available power supply voltages such as 24-volts, 12-volts, 5-volts, ground or negative 12-volts. Said available power supply voltages provide the required pull-in and sustaining voltage levels to drive the solenoid. [0072] The ASIC can measure the voltage on pin 208 by closing the low current switch 222 and reading the voltage converted by the analog-to-digital converter 216 . [0073] The ASIC can measure the current supplied to pin 208 by way of the high current switch 222 b by use of the multiple programmable current limiters 224 which contain current measurement apparatuses. Said current measurement is used to determine the solenoid inductance as well as to determine whether said solenoid coil is shorted or open. [0074] The periodic variation in voltage to the solenoid which is used to determine solenoid inductance is most easily accomplished by slightly varying the voltage of the plurality of power supplies 81 , said appropriate power supply being selected by supply selector 227 . The step change in voltage to the solenoid which is used to determine solenoid inductance is most easily accomplished by momentarily changing the supply selector 227 to increase or decrease the solenoid voltage in order to increase or decrease the solenoid current in order to effect the measurement of solenoid inductance. [0075] ASIC 198 has the ability to measure the amount of current flowing in or out of the node 208 labeled “Pin” in FIG. 13 . The pin driver circuit 198 in this case uses its A/D converter 216 to measure current flowing into or out of the pin node 208 , thereby enabling the detection of excessive current, or detecting whether a device connected to the Pin node 208 is functioning or wired correctly. [0076] ASIC 198 also has the ability to monitor the current flow into and out of the pin node 208 to unilaterally disconnect the circuit 198 , thereby protecting the ASIC 198 from damage from short circuits or other potentially damaging conditions. The ASIC 198 employs a so-called “abuse detect circuit” 218 to monitor rapid changes in current that could potentially damage the ASIC 198 . Low current switches 220 , 221 and 222 and high current switch 222 b respond to the abuse detect circuit 218 to disconnect the pin 208 . [0077] The ASIC 198 abuse detect circuit 218 has the ability to establish a current limit for the pin 208 , the current limit being programmatically set by the microprocessor 80 . This is indicated by selections 224 . [0078] The ASIC 198 can measure the voltage at the pin node 208 in order to allow the microprocessor 80 to determine the state of a digital input connected to the pin node. The threshold of a digital input can thereby be programmed rather than being fixed in hardware. The threshold of the digital input is set by the microprocessor 80 using the digital-to-analog converter 226 . The output of the digital-to-analog converter 226 is applied to one side of a latching comparator 225 . The other input to the latching comparator 225 is routed from the pin 208 and represents the digital input. Therefore, when the voltage of the digital input on the pin 208 crosses the threshold set by the digital-to-analog converter, the microprocessor 80 is able to determine the change in the input and thus deduce that the digital input has changed state. [0079] The ASIC 198 can measure a current signal presented at the pin node, the current signal being produced by various industrial control devices. The ASIC 198 can measure signals varying over the standard 4-20 mA and 0-20 mA ranges. This current measurement means is accomplished by the microprocessor 80 as it causes the selectable gain voltage buffer 231 to produce a convenient voltage such as zero volts at its output terminal. At the same time, the microprocessor 80 causes the selectable source resistor 228 to present a resistance to the path of current from the industrial control device and its current output. This current enters the ASIC 198 via the pin 208 . The imposed voltage on one side of a known resistance will cause the unknown current from the external device to produce a voltage on the pin 208 which is then measured via the analog-to-digital converter 216 through the low current switch 222 . The microprocessor 80 uses Ohm's Law to solve for the unknown current being generated by the industrial control device. [0080] The ASIC 198 includes functions as described above in reference to the interface apparatus 84 . For example, an ASIC 198 can include an interconnection apparatus 83 including a digital-to-analog converter 226 , wherein the microprocessor 80 is programmable to direct the reception of a digital signal from the microprocessor 80 and cause the signal to be converted by the digital-to-analog converter 226 to an analog signal, and to place a copy of the analog signal on the pin 208 . See FIGS. 6 and 13 . [0081] The ASIC 198 can also include an interconnection apparatus 83 including an analog-to-digital converter 216 , and wherein the microprocessor 80 is programmable to detect an analog signal on any selected contact 16 and cause the analog-to-digital converter 216 to convert the signal to a digital signal and output a copy of the digital signal to the microprocessor 80 . [0082] The ASIC 198 can also include a supply selector 227 , and a high current switch 222 b positioned between the selector 227 and the pin 208 . The microprocessor 80 is programmable to operate a supply selector 227 to cause a power supply voltage to be connected to a first contact 16 , and to cause a power supply return to be connected to a second contact 16 . [0083] Referring to FIG. 13 , there is a 2×8 cross-point switch 210 , that serves to connect a sensor to two adjacent pins 208 which are in turn connected to two adjacent device communication connectors 16 . The cross-point switch 210 allows a sensor such as a thermocouple to be connected to a precision differential amplifier 212 . The precision differential amplifier 212 may be connected via the low current switch 222 and the 2×8 cross-point switch 210 to the 4-way cross-point I/O 214 and then to another 4-way cross-point I/O 214 on an adjacent integrated circuit 19 (the integrated circuit for an adjacent contact 16 ). [0084] Other enhancements of the present invention include the ability of the module 15 to perform independent control of devices connected to the module 15 . If, for example, a solenoid is connected to the module 15 , then the microprocessor 80 can perform the required periodic or continuous measurement of inductance by causing the solenoid voltage to slightly vary and then measure the resulting current using the current measurement apparatuses in the programmable current limiters 224 . In addition, said microprocessor 80 can perform the required steps to shut down the solenoid by throttling or recirculating the current. The module 15 can thereby perform all the functions required to actuate a solenoid and verify its state, whether sealed or open. [0085] Referring to FIGS. 6 & 7 , the microprocessor 80 is generally configured/programmed by a controller 85 to receive instruction from the controller as required to sense a particular state of a selected device such as solenoid inductance and/or actuate a selected device, such as solenoid 10 , and provide the corresponding data to the system controller. The microprocessor 80 may also be programmed/directed by the controller to cause a particular signal to be applied to any selected one or more contacts 16 . In addition, the microprocessor 80 is programmed to respond to direction to send a selected signal type from one or more of devices to the system controller. In other words, the microprocessor controls the configuration of the interface apparatus 84 and generally the microprocessor is controlled by the system controller. Alternatively, the interface apparatus can be configured in response to a message stored in the memory of the microprocessor 80 of the module 15 . [0086] In some embodiments, the microprocessor 80 has an embedded web server. A personal computer may be connected to the module 15 using an Ethernet cable or a wireless communication device and then to the Internet. Here the personal computer may also be a system controller. The embedded web server provides configuration pages for each device connected to the module 15 . The user then uses a mouse, or other keyboard inputs, to configure the device function and assign input/output pins. The user may simply drag and drop icons on the configuration page to determine a specific interconnection apparatus for each of the contacts. In other embodiments, the microprocessor 80 uses a network connection to access a server on the Internet and receive from said server instructions to determine a specific interconnection apparatus for each of the contacts. [0087] As an example of the operation of the module 15 , the microprocessor 80 may be programmed to recognize particular input data, included for example in an Ethernet packet on a network cable connected to said microprocessor containing instructions to actuate a particular solenoid connected to said module 15 . [0088] The circuit switching apparatus (R 1 -R 12 ) are shown diagrammatically as electromechanical relays. In one embodiment, this switching apparatus is realized in a semiconductor circuit. (See FIG. 13 and related description.) A semiconductor circuit can be realized far less expensively and can act faster than an electromechanical relay circuit. An electromechanical relay is used in order to show the essence of the invention. [0089] While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes in the methods and apparatus disclosed herein may be made without departing from the scope of the invention which is defined in the appended claims.

A configurable, connectorized method and apparatus for driving a solenoid coil reduces energy consumption and heating of the solenoid coil, allows detection of the solenoid state, and simplifies connections to the solenoid.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application relates to commonly-owned, co-pending U.S. patent application Ser. Nos. ______ [Atty Docket Nos. YOR920050016us1 (D#18590); YOR920050083us1 (D#18650); YOR920050078us1 (D#18647); YOR920050080us1 (D#18645); YOR920050081us1 (D#18648); YOR920050082us1 (D#18649)] all filed on even date herewith and incorporated by reference as if fully set forth herein. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention generally relates to computer systems having multiprocessor architectures and, more particularly, to a novel multi-processor computer system for processing memory accesses requests and the implementation of cache coherence in such multiprocessor systems. [0004] 2. Description of the Prior Art [0005] To achieve high performance computing, multiple individual processors have been interconnected to form multiprocessor computer system capable of parallel processing. Multiple processors can be placed on a single chip, or several chips—each containing one or several processors—interconnected into a multiprocessor computer system. [0006] Processors in a multiprocessor computer system use private cache memories because of their short access time (a cache is local to a processor and provides fast access to data) and to reduce number of memory requests to the main memory. However, managing caches in multiprocessor system is complex. Multiple private caches introduce the multi-cache coherency problem (or stale data problem) due to multiple copies of main memory data that can concurrently exist in the multiprocessor system. [0007] Small scale shared memory multiprocessing system have processors (or groups thereof) interconnected by a single bus. However, with the increasing speed of processors, the feasible number of processors which can share the bus effectively decreases. [0008] The protocols that maintain the coherence between multiple processors are called cache coherence protocols. Cache coherence protocols track any sharing of data block between the processors. Depending upon how data sharing is tracked, cache coherence protocols can be grouped into two classes: 1) Directory based and 2) Snooping. [0009] In directory based approach, the sharing status of a block of physical memory is kept in just one location called the coherency directory. Coherency directories are generally large blocks of memory which keep track of which processor in the multiprocessor computer system owns which lines of memory. Disadvantageously, coherency directories are typically large and slow. They can severely degrade overall system performance since they introduce additional latency for every memory access request by requiring that each access to the memory go through the common directory. [0010] FIG. 1 illustrates a typical prior art multiprocessor system 10 using the coherence directory approach for cache coherency. The multiprocessor system 10 includes a number of processors 15 a , . . . , 15 d interconnected via a shared bus 24 to the main memory 20 a , 20 b via memory controllers 22 a , 22 b , respectively. Each processor 15 a , . . . , 15 d has its own private cache 17 a , . . . , 17 d , respectively, which is N-way set associative. Each request to the memory from a processor is placed on the processor bus 24 and directed to the coherency directory 26 . Frequently, in the coherency controller, a module is contained which tracks the location of cache lines held in particular subsystems to eliminated the need to broadcast unneeded snoop request to all caching agents. This unit is frequently labeled “snoop controller” or “snoop filter”. All memory access requests from the I/O subsystem 28 are also directed to the coherency controller 26 . Instead of the main memory, secondary cache connected to the main memory can be used. Processors can be grouped into processor clusters, where each cluster has its own cluster bus, which is then connected to the coherency controller 26 . As each memory request goes through the coherence directory, additional cycles are added to each request for checking the status of the requested memory block. [0011] In a snooping approach, no centralized state is kept, but rather each cache keeps the sharing status of data block locally. The caches are usually on a shared memory bus, and all cache controllers snoop (monitor) the bus to determine whether they have a copy of the data block requested. A commonly used snooping method is the “write-invalidate” protocol. In this protocol, a processor ensures that it has exclusive access to data before it writes that data. On each write, all other copies of the data in all other caches are invalidated. If two or more processors attempt to write the same data simultaneously, only one of them wins the race, causing the other processors' copies to be invalidated. [0012] To perform a write in a write-invalidate protocol based system, a processor acquires the shared bus, and broadcasts the address to be invalidated on the bus. All processors snoop on the bus, and check to see if the data is in their cache. If so, these data are invalidated. Thus, use of the shared bus enforces write serialization. [0013] Disadvantageously, every bus transaction in the snooping apporach has to check the cache address tags, which could interfere with CPU cache accesses. In most recent architectures, this is typically reduced by duplicating the address tags, so that the CPU and the snooping requests may proceed in parallel. An alternative approach is to employ a multilevel cache with inclusion, so that every entry in the primary cache is duplicated in the lower level cache. Then, snoop activity is performed at the secondary level cache and does not interfere with the CPU activity. [0014] FIG. 2 illustrates a typical prior art multiprocessor system 50 using the snooping approach for cache coherency. The multiprocessor system 50 contains number of processors 52 a , . . . , 52 c interconnected via a shared bus 56 to the main memory 58 . Each processor 52 a , . . . , 52 c has its own private cache 54 a , . . . , 54 c which is N-way set associative. Each write request to the memory from a processor is placed on the processor bus 56 . All processors snoop on the bus, and check their caches to see if the address written to is also located in their caches. If so, the data corresponding to this address are invalidated. Several multiprocessor systems add a module locally to each processor to track if a cache line to be invalidated is held in the particular cache, thus effectively reducing the local snooping activity. This unit is frequently labeled “snoop filter”. Instead of the main memory, secondary cache connected to the main memory can be used. [0015] With the increasing number of processors on a bus, snooping activity increases as well. Unnecessary snoop requests to a cache can degrade processor performance, and each snoop requests accessing the cache directory consumes power. In addition, duplicating the cache directory for every processor to support snooping activity significantly increases the size of the chip. This is especially important for systems on a single chip with a limited power budget. [0016] What now follows is a description of prior art references that address the various problems of conventional snooping approaches found in multiprocessor systems. [0017] Particularly, U.S. Patent Application US2003/0135696A1 and U.S. Pat. No. 6,704,845B2 both describe replacement policy methods for replacing entries in the snoop filter for a coherence directory based approach including a snoop filter. The snoop filter contains information on cached memory blocks—where the cache line is cached and its status. The U.S. Patent Application US2004/0003184A1 describes a snoop filter containing sub-snoop filters for recording even and odd address lines which record local cache lines accessed by remote nodes (sub-filters use same filtering approach). Each of these disclosures do not teach or suggest a system and method for locally reducing the number of snoop requests presented to each cache in a multiprocessor system. Nor do they teach or suggest coupling several snoop filters with various filtering methods, nor do they teach or suggest providing point-to-point interconnection of snooping information to caches. [0018] U.S. Patent Applications US2003/0070016A1 and US2003/0065843A1 describe a multi-processor system with a central coherency directory containing a snoop filter. The snoop filter described in these applications reduces the number of cycles to process a snoop request, however, does not reduce the number of snoop requests presented to a cache. [0019] U.S. Pat. No. 5,966,729 describes a multi-processor system sharing a bus using a snooping approach for cache coherence and a snoop filter associated locally to each processor group. To reduce snooping activity, a list of remote processor groups “interested” and “not-interested” in particular cache line is kept. Snoop requests are forwarded only to the processor groups marked as “interested” thus reducing the number of broadcasted snoop requests. It does not describe how to reduce the number of snoop requests to a local processor, but rather how to reduce the number of snoop requests sent to other processor groups marked as “not interested”. This solution requires keeping a list with information on interested groups for each line in the cache for a processor group, which is comparable in size to duplicating the cache directories of each processor in the processor group thus significantly increasing the size of chip. [0020] U.S. Pat. No. 6,389,517B1 describes a method for snooping cache coherence to allow for concurrent access on the cache from both the processor and the snoop accesses having two access queues. The embodiment disclosed is directed to a shared bus configuration. It does not describe a method for reducing the number of snoop requests presented to the cache. [0021] U.S. Pat. No. 5,572,701 describes a bus-based snoop method for reducing the interference of a low speed bus to a high speed bus and processor. The snoop bus control unit buffers addresses and data from the low speed bus until the processor releases the high speed bus. Then it transfers data and invalidates the corresponding lines in the cache. This disclosure does not describe a multiprocessor system where all components communicate via a high-speed bus. [0022] A. Moshovos, G. Memik, B. Falsafi and A. Choudhary, in a reference entitled “JETTY: filtering snoops for reduced energy consumption in SMP servers” (“Jetty”) describe several proposals for reducing snoop requests using hardware filter. It describes the multiprocessor system where snoop requests are distributed via a shared system bus. To reduce the number of snoop requests presented to a processor, one or several various snoop filters are used. [0023] However, the system described in Jetty has significant limitations as to performance, supported system and more specifically interconnect architectures, and lack of support for multiporting. More specifically, the approach described in Jetty is based on a shared system bus which established a common event ordering across the system. While such global time ordering is desirable to simplify the filter architecture, it limited the possible system configurations to those with a single shared bus. Alas, shared bus systems are known to be limited in scalability due to contention to the single global resource. In addition, global buses tend to be slow, due to the high load of multiple components attached to them, and inefficient to place in chip multiprocessors. [0024] Thus, in a highly optimized high-bandwidth system, it is desirable to provide alternate system architectures, such as star, or point-to-point implementations. These are advantageous, as they only have a single sender and transmitter, reducing the load, allowing the use of high speed protocols, and simplifying floor planning in chip multiprocessors. Using point to point protocols also allows to have several transmissions in-progress simultaneously, thereby increasing the data transfer parallelism and overall data throughput. [0025] Other limitations of Jetty include the inability to perform snoop filtering on several requests simultaneously, as in Jetty, simultaneous snoop requests from several processors have to be serialized by the system bus. Allowing the processing of several snoop requests concurrently would provide a significant increase in the number of requests which can be handled at any one time, and thus increase overall system performance. [0026] Having set forth the limitations of the prior art, it is clear that what is required is a system incorporating snoop filters to increase overall performance and power efficiency without limiting the system design options, and more specifically, methods and apparatus to support snoop filtering in systems not requiring a common bus. [0027] Furthermore, there is a need for a snoop filter architecture supporting systems using point-to-point connections to allow the implementation of high performance systems using snoop filtering. [0028] There is a further need for the simultaneous operation of multiple snoop filter units to concurrently filter requests from multiple memory writers to increase system performance. [0029] There is further a need to provide novel, high performance snoop filters which can be implemented in a pipelined fashion to enable high system clock speeds in systems utilizing such snoop filters. [0030] There is an additional need for snoop filters with high filtering efficiency transcending the limitations of prior art. SUMMARY OF THE INVENTION [0031] It is therefore an object of the present invention to provide a simple method and apparatus for reducing the number of snoop requests presented to a single processor in cache coherent multiprocessor systems. [0032] It is a further object of the present invention to provide a simple method and apparatus for supporting snoop filtering in multiprocessor system architectures. While prior art has allowed snoop filtering to be used only in bus-based system, the present invention teaches how to advantageously use snoop filtering in conjunction with point to point protocols by permitting several transmissions in-progress simultaneously, thereby increasing the data transfer parallelism and overall data throughput. [0033] In accordance with the present invention, there is provided a snoop filtering method and apparatus for supporting cache coherency in a multiprocessor computing environment having multiple processing units, each processing unit having one or more local cache memories associated and operatively connected therewith. The method comprises providing a snoop filter device associated with each processing unit, each snoop filter device having a plurality of dedicated input ports for receiving snoop requests from dedicated memory writing sources in the multiprocessor computing environment. Each snoop filter device includes a plurality of parallel operating port snoop filters in correspondence with the plurality of dedicated input ports that are adapted to concurrently filter snoop requests received from respective dedicated memory writing sources and forward a subset of those requests to its associated processing unit. [0034] According to the invention, there is provided a snoop filtering method and a snoop filter apparatus associated with a processing unit of a computing environment having multiple processing units for supporting cache coherency in the computing environment, the snoop filter apparatus comprising: a plurality of inputs, each receiving a snoop request from a dedicated memory writing source in the computing environment; a snoop filter means provided for each input and adapted to concurrently filter received respective snoop requests from respective dedicated memory writing sources, each snoop filter means implementing one or more parallel operating sub-filter elements adapted for processing received snoop requests and forwarding a subset thereof to the associated processing unit, whereby as a result of the concurrent filtering, a number of snoop requests forwarded to a processing unit is significantly reduced thereby increasing performance of the computing environment. [0038] In accordance with the present invention, one of said one or more parallel operating sub-filter elements comprises an address range filter means for determining whether an address of a received snoop request is within an address range comprising a minimum range address and a maximum range address. [0039] Furthermore, one of said one or more parallel operating sub-filter elements comprises a snoop cache device adapted for tracking snoop requests received at the snoop filter means and recording addresses corresponding to snoop requests received; and, a snoop cache logic means in one to one correspondence with a respective snoop cache for comparing a received snoop request address against all addresses recorded in the corresponding snoop cache device, and, one of forwarding said received snoop request to the associated processing unit when an address does not match in the respective snoop cache device, or discarding the snoop request when an address match is found in the snoop cache device. [0040] Furthermore, the processing unit has one or more cache memories associated therewith, and the snoop filter means comprises a memory storage means adapted to track cache line addresses of data that have been loaded into a cache memory level of its associated processor and record the cache line addresses. Accordingly, one of the one or more parallel operating sub-filter elements comprises a stream register check means for comparing an address of the received snoop request against corresponding addresses stored in the memory storage means; and, one of forwarding said received snoop request to said processor in response to matching an address in the memory storage means, or otherwise discarding the snoop request. [0041] In one embodiment, the memory storage means comprises a plurality of stream register sets, each stream register set comprising a base register and a corresponding mask register pair, the base register tracking address bits common to all of the cache lines represented by the stream register; and, the corresponding mask register tracking bits representing differences to prior recorded addresses included in its corresponding base register. [0042] Furthermore, each of the one or more parallel operating sub-filter elements generates a signal indicating whether a snoop request is to be forwarded to said associated processor or not forwarded. The snoop filter means further comprising: a means responsive to each signal generated from the sub-filter element for deciding whether a snoop request is to be forwarded or discarded. [0043] Advantageously, the present invention enables snoop filtering to be performed on several requests simultaneously, while in the prior art systems, simultaneous snoop requests from several processors have to be serialized by the system bus. Allowing the processing of several snoop requests concurrently provides a significant increase in the number of requests which can be handled at any one time, and thus increase overall system performance. BRIEF DESCRIPTION OF THE DRAWINGS [0044] The objects, features and advantages of the present invention will become apparent to one skilled in the art, in view of the following detailed description taken in combination with the attached drawings, in which: [0045] FIG. 1 depicts a base multiprocessor architecture with the coherence directory for cache coherency according to the prior art; [0046] FIG. 2 depicts a base multiprocessor system using snooping approach for cache coherency according to the prior art; [0047] FIG. 3 depicts a base multiprocessor system using snooping approach for cache coherency using a point-to-point connection described according to the present invention; [0048] FIG. 4 illustrates an alternative embodiment base multiprocessor system using snooping approach for cache coherency using point-to-point connection where snoop filter is placed between the L 2 cache and the main memory; [0049] FIG. 5 depicts a high level schematic of a snoop filter block in accordance with a preferred embodiment of the invention; [0050] FIG. 6 is a high level schematic of the snoop block containing multiple snoop filters according to the present invention; [0051] FIG. 7 illustrates a high level schematic of a single snoop port filter according to the present invention; [0052] FIGS. 8 ( a ) and 8 ( b ) depict high level schematics of two alternative embodiments of the snoop block according to the present invention; [0053] FIG. 9 is a is a high level schematic of the snoop block including multiple port snoop filters according to a further embodiment of the present invention; [0054] FIG. 10 depicts the control flow for the snoop filter implementing snoop cache for a single snoop source according to the present invention; [0055] FIG. 11 depicts a control flow logic for adding a new entry to the port snoop cache inaccordance with the present invention; [0056] FIG. 12 depicts a control flow logic for removing an entry from the snoop cache in accordance with the present invention; [0057] FIG. 13 depicts a block diagram of the snoop filter implementing stream registers in accordance with the present invention; [0058] FIG. 14 depicts another embodiment of the snoop filter implementing stream registers filtering approach in accordance with the present invention; [0059] FIG. 15 is a block diagram depicting the control flow for the snoop filter using paired stream registers and masks sets according to the invention; and, [0060] FIG. 16 is a block diagram depicting the control flow for updating two stream register sets and the cache wrap detection logic for the replaced cache lines according to the invention; [0061] FIG. 17 illustrates block diagram of signature filters to provide additional filtering capability to stream registers; [0062] FIG. 18 is the block diagram of filtering mechanism using signature files in accordance with the present invention; [0063] FIGS. 19 ( a ) and 19 ( b ) depict exemplary cache wrap detection logic circuitry (registers and comparator) for an N-way set-associative cache; [0064] FIG. 20 depicts an exemplary cache wrap detection logic circuitry for an N-way set-associative cache according to a second embodiment of the invention that is based on a loadable counter; and, [0065] FIG. 21 depicts an exemplary cache wrap detection logic circuitry for an N-way set-associative cache according to a third embodiment of the invention that is based on a scoreboard register. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0066] Referring now to drawings, and more particularly to FIG. 3 , there is shown the overall base architecture of the multiprocessor system with the use of snooping approach for cache coherency. In the preferred embodiment, the multiprocessor system is composed of N processors 100 a , . . . , 100 n (or CPUs labeled DCU 1 to DCU N ) with their local L 1 data and instruction caches, and their associated L 2 caches 120 a , . . . , 120 n . The main memory 130 is shared and can be implemented on-chip or off-chip. In the alternative embodiment, instead of main memory, a shared L 3 with access to main memory can be used. In the preferred embodiment, the processor cores 100 a , . . . , 100 n are PowerPC cores such as PPC440 or PPC405, but any other processor core can be used, or some combination of various processors in a single multiprocessor system can be used without departing from the scope of this invention. The processor cores 100 a , . . . , 100 n are interconnected by a system local bus 150 . [0067] To reduce the number of snoop requests presented to a processor, and thus to reduce the impact of snooping on processor and system performance, and to reduce power consumed by unnecessary snoop requests, a snoop filter 140 a , . . . , 140 n is provided for each respective processor core 100 a , . . . , 100 n in the multiprocessor system 10 . For transferring snooping requests, the preferred embodiment does not use the system bus 150 , as typically found in prior art systems, but rather implements a point-to-point interconnection 160 whereby each processor's associated snoop filter is directly connected with each snoop filter associated with every other processor in the system. Thus, snoop requests are decoupled from all other memory requests transferred via the system local bus, reducing the congestion of the bus which is often a system bottleneck. All snoop requests to a single processor are forwarded to the snoop filter 140 a , . . . , 140 n , which comprises several sub-filters with the same filtering method, or with several different filtering methods, or any combination of the two, as will be described in greater detail herein. The snoop filter processes each snoop request, and presents only a fraction of all requests which are possibly in the processor's cache to the processor. [0068] For each processor, snoop requests are connected directly to all other processors' snoop filters using a point-to-point interconnection 160 . Thus, several snoop requests (resulting from write and invalidate attempts) from different processors can occur simultaneously. These requests are no longer serialized, as in the typical snooping approach using the system bus, where this serialization is performed by the bus. That is, multiple snoop requests can be processed in the snoop filter concurrently, as will be described herein in further detail. As a processor has only one snoop port, the snoop requests not filtered out by a snoop filter will be serialized in a queue to be presented to the processor. However, the number of requests passed to the processor is much less than the pre-filtered number of all snoop requests, reducing the impact of cache coherence implementation on system performance. [0069] To prevent queue overflowing condition of the queues contained in the snoop filter block, a token-based flow control system is implemented for each point to point link to limit the number of simultaneously outstanding requests. According to the token-based flow control, each memory writer can send the next write request—which also initiates snoop requests to all other processor units and accompanied snoop filter blocks—only if it has tokens available for all ports of the snoop filter blocks it has a direct point-to-point connection. If there are no tokens available from at least one of the remote ports it is connected to, no snoop requests can be sent out from this memory writer until at least one token from the said snoop filter port gets available again. [0070] FIG. 4 illustrates an alternative embodiment of this invention, with a base multiprocessor system using a snooping approach for cache coherency with point-to-point interconnection for snooping requests, wherein the snoop filter is placed between the L 2 cache and the main memory 230 . The multiprocessor system according to this embodiment thus comprises N processors 200 a , . . . , 200 n (or CPUs labeled DCU 1 to DCU N ) with their local L 1 data and instruction caches, and their associated L 2 caches 220 a , . . . , 220 n . The main memory 230 is shared and can be implemented on-chip or off-chip. In the alternative embodiment, instead of main memory, a shared L 3 cache with access to main memory can be used. All memory access requests from processors 200 a , . . . , 200 n are transferred via a system local bus 250 . In the embodiment depicted in FIG. 4 , each of the processors in the multiprocessor system is paired with a respective snoop filter 240 a , . . . , 240 n . The point-to-point interconnection 260 is used to transfer snoop requests in the preferred embodiment in order to reduce the congestion of the system bus. In this point-to-point connection scheme 260 , each processor's associated snoop filter is directly connected with each snoop filter associated with every other processor in the system. All snoop requests to a single processor are forwarded to its snoop filter, which processes each snoop request, and forwards only an appropriate fraction of all requests to the processor. In this embodiment, the snoop requests are filtered at the L 2 cache level (not at L 1 , as in the previous embodiment illustrated in FIG. 3 ), but the presented invention is applicable to any cache level, and can be used for other levels of the cache hierarchy without departing from the scope of the invention. [0071] Referring now to FIG. 5 , there is depicted a high level block diagram of the snoop filter device according to the present invention. Snoop requests from all other processors 1 to N in a multiprocessor system are forwarded to the snoop block 310 via dedicated point-to-point interconnection inputs 300 a , . . . , 300 n . The snoop block 310 filters the incoming snoops and forwards the appropriate subset to the processor 320 via the processor snoop interface 340 . In addition, the snoop block 310 monitors all memory access requests from the processor and L 1 data cache block 320 to the L 2 cache 330 . These are only requests which miss in the L 1 cache. The snoop block monitors all read address and control signals 360 and 362 to update its filters accordingly. [0072] FIG. 6 depicts a high level schematic of the snoop block 310 depicted in FIG. 5 . As shown in FIG. 6 , the snoop block 310 includes multiple (“N”) port snoop filters 400 a , . . . , 400 n that operate in parallel, with each dedicated only to one source of N memory writers (processors or a DMA engine sub-system, etc.). Each of the port snoop filters 400 a , . . . , 400 n receive on its dedicated input 410 a , . . . , 410 n snoop requests from a single source which is directly connected point-to-point. As will be described herein, a single port snoop filter may include a number of various snoop filter methods. The snoop block 310 additionally includes a stream register block 430 and snoop token control block 426 . In addition, each port snoop filter 400 a , . . . , 400 n monitors all memory read access requests 412 from its associated processor which miss in the processor's L 1 level cache. This information is also provided to the stream register block 430 for use as will be described in greater detail herein. [0073] In operation, the port snoop filters 400 a , . . . , 400 n process the incoming snoop requests and forward a subset of all snoop requests to a respective snoop queue 420 a , . . . , 420 n having one queue associated with each snoop port. A queue arbitration block 422 is provided that arbitrates between all the snoop queues 420 and serializes all snoop requests from the snoop queues 420 fairly. Logic is provided to detect a snoop queue overflow condition, and the status of each queue is an input to a snoop token control unit 426 that controls flow of snoop requests from the remote memory writers. A memory writer—being a processor or a DMA engine—can submit a write to the memory and a snoop request to all snoop filters only if it has a token available from all snoop filters. The only snoop filter from which a processor does not need a token available to submit a write is its own local snoop filter. This mechanism ensures that the snoop queues do not overflow. From the snoop queue selected by arbiter 422 , snoop requests are forwarded to the processor via a processor snoop interface 408 . [0074] FIG. 7 illustrates a high level schematic of a single snoop port filter 400 . The snoop port filter block 400 includes multiple filter units which implement various filtering algorithms. In the preferred embodiment, three snoop filter blocks 440 , 444 , and 448 operate in parallel, each implementing a different snoop filter algorithm. The snoop filter blocks are labeled snoop cache 440 , stream register check unit 444 , and range filter 448 . In one embodiment, each of the parallel snoop filter blocks receives on its input an identical snoop request 410 from a single source simultaneously. In addition, the snoop cache 440 monitors all memory read access requests 412 from the processor which miss in the L 1 level cache, and stream registers check unit 444 receives status input 432 from the stream register unit 430 depicted in FIG. 6 . [0075] According to the preferred embodiment, the snoop cache block 440 filters the snoop requests 410 using an algorithm which is based on the temporal locality property of snoop requests, meaning that if a single snoop request for a particular location was made, it is probable that another request to the same location will be made soon. The snoop cache monitors every load made to the local cache, and updates its status, if needed. The stream register check block 444 filters snoop requests 410 using an algorithm that determines a superset of the current local cache content. The approximation of cache content is included in the stream registers block 430 ( FIG. 6 ), and the stream register status 432 is forwarded to each snoop port filter 400 . Based on this status, for each new snoop requests 410 , a decision is made if the snoop address can possibly be contained in the local cache. The third filtering unit in the snoop port filter is the range filter 448 . For this filtering approach, two range addresses are specified, the minimum range address and the maximum range address. The filtering of a snoop request is performed by first determining if the snoop request is within the address range determined by these two range addresses. If this condition is met, the snoop request is discarded; otherwise, the snoop request is forwarded to the decision logic block 450 . Conversely, the request can be forwarded when it falls within the address range and discarded otherwise, without departing from the scope of the invention. Particularly, the decision logic block 450 receives results 456 of all three filter units 440 , 444 and 448 together with the control signals 454 which enable or disable each individual snoop filter unit. Only results of snoop filter units for which the corresponding control signals are enabled are considered in each filtering decision. If any one of the filtering units 440 , 444 or 448 decides that a snoop request 410 should be discarded, the snoop request is discarded. The resulting output of this unit is either to add the snoop request to the corresponding snoop queue 452 , or to discard the snoop request and return a snoop token 458 to the remote processor or DMA unit that initiated the discarded snoop request. [0076] In the preferred embodiment, only the three filtering units implementing the algorithms above described are included in a port snoop filter, but one skilled in the art will appreciate that any other number of snoop filter units can be included in a single port snoop filter, or that some other snoop filter algorithm may be implemented in the port snoop filter, or a combination of snoop algorithms can be implemented, without departing from the scope of the invention. [0077] FIGS. 8 ( a ) and 8 ( b ) depict high level schematics of two alternative embodiments of the snoop filter block 310 of FIG. 6 . As described herein with respect to FIG. 6 , the snoop block may include multiple snoop filters that can use various filtering approaches, the same filtering approach, or a combination of the two. As shown in FIG. 8 ( a ), N port snoop filters 460 a , . . . , 460 n operate in parallel, one for each of N remote memory writers. Each of the port snoop filters 460 a , . . . , 460 n receive on its respective input 462 a , . . . , 462 n snoop requests from a single dedicated source which is connected point-to-point. In addition, each snoop filter 460 a , . . . , 460 n monitors all of the local processor's memory load requests 464 which have missed in the L 1 level cache. Other signals from other units of the snoop block may also be needed to supply to the port snoop filters, if required by the filter algorithm implemented. The exact signals needed are determined by the one or more snoop filter algorithms implemented in a single port snoop filter 460 . Additionally, it should be understood that all port snoop filters do not have to implement the same set of filtering algorithms. [0078] The port snoop filters 460 a , . . . , 460 n filter the incoming snoops and forward the appropriate unfiltered subset of snoop requests into the respective queues 466 a , . . . , 466 n and the queue arbitration block 468 . Here, the snoop requests are serialized and presented to a next snoop filter 470 , which handles inputs from all remote memory writers. This shared snoop filter 470 processes all snoop request presented and forwards a subset of all requests to the snoop queue 472 . From the snoop queue 472 , snoop requests are forwarded to the processor via the processor snoop interface 474 . It should be understood that it is possible to have multiple or no shared snoop filters 470 instead of the configuration shown in FIG. 8 ( a ). In the case of multiple shared filters, the filters may be arranged in parallel or in series (in which case the output of one filter is the input to the next, for example). If a filter has inputs from more than one source (i.e., is shared between multiple sources), it has to have its own input queue and an arbiter to serialize snoop requests. A final ordered subset of all snoop requests is placed in the snoop queue 472 , and snoop requests are forwarded to the processor via the processor snoop interface 474 . Optionally, a snoop queue full indication signal 476 is provided that indicates when the snoop queue is full in order to stop some or all remote memory writers from issuing further snoop requests until the number of snoops in the snoop queue falls below a predetermined level. [0079] Similarly, FIG. 8 ( b ) illustrates another embodiment with an alternative organization of the snoop filters in the snoop block 310 . N port snoop filters 480 a , . . . , 480 n , each receiving only snoop requests from one of N remote memory writers (i.e., excluding the processor where the snoop filter is attached), operate in parallel. Each port snoop filter 480 a , . . . , 480 n receives on its respective input snoop requests 482 a , . . . , 482 n from only a single source, respectively. A shared snoop filter 484 is connected in parallel with the port snoop filter devices 480 a , . . . , 480 n . In an alternative embodiment, more than one shared snoop filter can be attached in parallel. The shared snoop filter 484 handles inputs from all N remote memory writers. Having more than one input, the shared filter 484 has its own input queues 486 and a queue arbiter 488 for serializing snoop requests. Further in the embodiment depicted in FIG. 8 ( b ), all port snoop filters 480 a , . . . , 480 n and the shared snoop filter 484 monitor all memory read access requests 490 from the local processor which miss in the L 1 level cache. The snoop filters 480 a , . . . , 480 n and 484 filter the incoming snoop requests and forward the appropriate unfiltered subset to the input queue of the next shared snoop filter 492 a , . . . , 492 n . Here, the unfiltered snoop requests are serialized by the queue arbiter 494 , and are forwarded to the processor via the processor snoop interface 496 . If one of the snoop queue devices 492 a , . . . , 492 n or 486 is full, a snoop queue full indication 498 is activated to stop all (or some of) the remote memory writers from issuing further snoop requests until the number of snoops in the snoop queue falls below a the predetermined level. [0080] Referring now to FIG. 9 , there is depicted a further embodiment of the snoop filter block 310 . The block contains N port snoop filters 500 a , . . . , 500 n , corresponding to port snoop filters 400 , 460 a , . . . , 460 n , and 480 a , . . . , 480 n (of FIGS. 8 ( a ) and 8 ( b )). Each port snoop filter 500 a , . . . , 500 n includes a snoop cache device 502 a , . . . , 502 n , and a snoop check logic 504 a , . . . , 504 n . The snoop cache devices 502 a , . . . , 502 n implement a snoop filtering algorithm which keeps track of recent snoop requests from one source, where the source of snoop requests can be another processor, a DMA engine, or some other unit. For each new snoop request from a single source, the snoop request's address is checked against the snoop cache in the snoop check logic block 504 . If the result of this comparison matches, i.e., the snoop request is found in the snoop cache, the snooped data is guaranteed not to be in the local L 1 level cache of the processor. Thus, no snoop request is forwarded to the snoop queue 506 and the snoop queue arbiter 508 . If no match is found in the snoop cache 502 a , . . . , 502 n for the current snoop request, the address of the snoop requests is added to the snoop cache using the signals 514 a , . . . , 514 n . Concurrently, the snoop request is forwarded to the snoop queue 506 . [0081] All snoop cache devices 502 a , . . . , 502 n also receive read addresses and requests 512 from the local processor, and compare the memory read access addresses to the entries in the snoop cache 502 a , . . . , 502 n . If a request matches one of the entries in the snoop cache, this entry is removed from the snoop cache, as now the cache line is going to be located in the processor's first level cache. In the preferred embodiment, multiple snoop caches operating in parallel are used, each keeping track of snoop requests from a single remote memory writer. After filtering, a fraction of unfiltered snoop requests can be forwarded to the next port snoop filter, or they can be queued for one or more shared snoop filters, or they are placed in the snoop queue of the processor interface, depending on the embodiment. [0082] It is understood that a single snoop cache device 502 includes an internal organization of M cache lines (entries), each entry having two fields: an address tag field, and a valid line vector. The address tag field of the snoop cache is typically not the same as the address tag of the L 1 cache for the local processor, but it is shorter by the number of bits represented in the valid line vector. Particularly, the valid line vector encodes a group of several consecutive cache lines, all sharing the same upper bits represented by the corresponding address tag field. Thus, the n least significant bits from an address are used for encoding 2 n consecutive L 1 cache lines. In the extreme case when n is zero, the whole entry in the snoop cache represents only one L 1 cache line. In this case, the valid line vector has only one bit corresponding to a “valid” bit. [0083] The size of the address tag field in the snoop cache is determined by the size of the L 1 cache line and the number of bits used for encoding the valid line vector. In an example embodiment, for an address length of 32 bits ( 31 : 0 ), an L 1 cache line being 32 bytes long, and a valid line vector of 32 bits, address bits ( 31 : 10 ) are used as the address tag field, (bit 31 being the most significant), address bits ( 9 : 5 ) are encoded in the valid line vector, and address bits ( 4 : 0 ) are ignored because they encode the cache line byte offset. As an illustration, three snoop caches for three different memory writers (N=3) are listed below, each snoop cache having M=4 entries, with address tag field to the left, and with 5 bits from the address used to encode the valid line vector to track 32 consecutive cache lines: [0084] Snoop Requests Source 1 Entry 1: 01c019e 00000000000000000001000000000000 Entry 2: 01c01a0 00000000000000000000000100000000 Entry 3: 01c01a2 00000000000000000000000000010000 Entry 4: 01407ff 00000000000000000000000110000000 [0089] Snoop Requests Source 2 Entry 1: 01c01e3 00010000000000000000000000000000 Entry 2: 01c01e5 00000001000000000000000000000000 Entry 3: 01c01e7 00000000000100000000000000000000 Entry 4: 0140bff 00000000000000000000000110000000 [0095] Snoop Requests Source 3 Entry 1: 01c0227 00000000000000000001000000000000 Entry 2: 01c0229 00000000000000000000000100000000 Entry 3: 01c022b 00000000000000000000000000010000 Entry 4: 0140fff 00000000000000000000000110000000 [0100] In this example, entry 1 of the source 1 snoop cache has recorded that address 01c019ec hexadecimal has been invalidated recently and cannot possibly be in the L 1 cache. Therefore, the next snoop request to the same cache line will be filtered out (discarded). Similarly, entry 4 of the source 1 snoop cache will cause snoop requests for cache line addresses 01407ff7 and 01407ff8 to be filtered out. [0101] Referring now to FIG. 10 , the control flow for the snoop filter implementing a snoop cache device for a single snoop source is shown. At the start of operation, all M lines in the snoop cache are reset as indicated at step 600 . When a new snoop request from a snoop source i is received, the address of the snoop request is parsed into the “address tag” field 526 and into bits used for accessing the valid line vector 524 . The valid line vector of the snoop request has only one bit corresponding to each L 1 cache with address bits matching the address tag field. This is performed in the step 602 . In the step 604 , the “tag” field of the snoop request is checked against all tag fields in the snoop cache associated with the snoop source i. If the snoop request address tag is the same as one of the address tags stored in the snoop cache, the address tag field has hit in the snoop cache. After this, the valid line vector of the snoop cache entry for which a hit was detected is compared to the valid line vector of the snoop request. If the bit of the valid line vector in the snoop cache line corresponding to the bit set in the valid line vector of the snoop request is set, the valid line vector has hit as well. In one preferred embodiment, the valid line vector check is implemented by performing a logical operation upon the bit operands. Thus, for example, the valid line vector check may be performed by AND-ing the valid line vector of the snoop request with the valid line vector of the snoop cache line, and checking if the result is zero. It is understood that other implementations may additionally be used without departing from the scope of this invention. It is further understood that checking for a valid line vector hit can be implemented in parallel with checking for an address tag hit. [0102] At step 606 , a determination is made as to whether both the “tag’ field matches and the corresponding bit in the valid line vector is set. If both the “tag’ field matches and the corresponding bit in the valid line vector is set, the snoop request is guaranteed not to be in the cache as indicated at step 606 . Thus, this snoop request is not forwarded to the cache; it is filtered out as indicated at step 608 . [0103] Otherwise, if the address “tag” field hits in the snoop cache but the bit in the valid line vector is not set or, alternately, if the tag does not hit in the snoop cache, this indicates that the line may be in the cache. Consequently, the snoop request is forwarded to the cache by placing it into a snoop queue as indicated at step 612 . This snoop request is also added as a new entry to the snoop cache as shown at step 610 . [0104] Referring now to FIG. 11 , there is shown the details of step 610 ( FIG. 10 ) describing the process of adding new information in the snoop cache. This is accomplished by several tasks, as will now be described. At step 614 , a determination is first made as to whether the address tag is already stored in the snoop cache (i.e., the address tag was a hit). For this step, the information calculated in step 602 ( FIG. 10 ) can be used. If the address tag check gave a hit, then the process proceeds to step 624 , where the bit in the valid line vector of the selected snoop cache entry corresponding to the snoop request is set. If the address tag check gave a miss in step 614 , a new snoop cache entry has to be assigned for the new address tag, and the process proceeds to 616 where a determination is made as to whether there are empty entries available in the snoop cache. If it is determined that empty entries are available, then the first available empty entry is selected as indicated at step 620 . Otherwise, if it is determined that there are no empty entries in the snoop cache, one of the active entries in the snoop cache is selected for the replacement as indicated at step 618 . The replacement policy can be round-robin, least-recently used, random, or any other replacement policy known to skilled artisans without departing from the scope of this invention. Continuing to step 622 , the new address tag is then written in the selected snoop cache line and the corresponding valid line vector is cleared. Then, as indicated at step 624 , the bit in the valid line vector of the selected snoop cache entry corresponding to the bit set in the valid line vector of the snoop request is set. [0105] In yet another embodiment, the new information is not added into the snoop cache based on the hit or miss of a snoop request in the snoop cache only, but instead, the addition of new values—being whole snoop cache lines or only setting a single bit in a valid line vector—is based on the decision of the decision logic block 450 ( FIG. 7 ). In this embodiment, the new information is added into the snoop cache only if the decision logic block does not filter out the snoop request. If any other filter in the snoop port filter block 400 ( FIG. 7 ) filters out the snoop request (i.e., determines that the data are not in the local L 1 cache), no new information is added to the snoop cache, but the operation steps are the same as for snoop cache hit case. The advantage of this embodiment is that the snoop cache performs better because less redundant information is stored. [0106] Referring now to FIG. 12 , there is depicted the control flow for removing an entry from a snoop cache. On each local processor memory read request which misses in the local L 1 level cache, the address of the memory request is checked against all entries in all snoop caches associated with all snoop request sources. In step 630 , the address of the memory read request is parsed into an address tag field and into bits used for encoding the valid line vector. This is performed in the step 630 . In the step 632 , a determination is made as to whether there are one or more tag hits. This is accomplished by checking the “tag” field of the memory request against all tag fields in all snoop caches associated with all snoop sources. If the tag check misses, this address is not being filtered out and nothing has to be done. Thus, the control flow loops back to step 630 to wait for the next cache miss from the processor. [0107] Returning to step 632 , if it is determined that the comparison of the address tag with all snoop caches results in one or more hits, the information has to be removed from all snoop caches for which it was hit. Thus, at step 634 , the appropriate low order bits of the memory read address are decoded into a valid line vector, and is matched against the valid line vector of the snoop cache entry that was hit as indicated in step 635 . Proceeding now to step 636 , it is determined whether the unique bit set in the read address vector is also set in the valid line vector of the snoop cache. If there is no such valid line vector hit (regardless of the address tag field hit), this memory address is not filtered out and nothing has to be changed in the particular snoop cache. Thus, the control flow proceeds to step 640 to check if all address tag hits have been processed, and if not, the process returns to step 635 . [0108] If, however, it is determined at step 636 that the read address vector hits in the valid line vector, then the read address is being filtered out. The corresponding valid line vector bit has to be cleared since the memory read address is going to be loaded into the first level cache. This clearing of the corresponding bit in the valid line vector is performed at step 638 . If after removing the corresponding bit from the valid line vector the number of bits set of the valid line vector becomes zero, the address tag field is further removed from the snoop cache causing the entry to be empty. As next indicated at step 640 , the same process of checking for the valid line vector bit, its clearing, and clearing of the address tag—if necessary—is repeated for all snoop caches which hit the memory read request which was miss in the local L 1 cache. This condition that all hit address tag lines have been processed is checked at step 640 . Once all of the cache lines have been checked, the process returns to step 630 . [0109] In yet another embodiment, the local memory request is compared to all address tags in all snoop caches simultaneously. Concurrently, the valid line vector encoding of the local memory request may be compared with all valid line vectors in all snoop caches in which there were hits simultaneously. Then, these two results—address tag hit and valid line vector hit—can be combined to determine all snoop cache lines from which the corresponding valid line vector bit has to be removed, and all these bits can be removed from the hitting cache lines from all snoop caches simultaneously. [0110] Referring now to FIG. 13 , there is depicted the block diagram of the snoop filter device implementing stream registers. In one preferred embodiment, the snoop filter unit comprises the following elements: two sets of stream registers and masks 700 , a snoop check logic block 702 , a cache wrap detection logic block 706 , a stream register selection logic block 704 , filter queues 703 , and a processor arbitrate and multiplex logic 710 . As will be described in greater detail herein, unlike the snoop cache filters that keep track of what is not in the cache, the stream registers and masks sets 700 keep track of recent data which were loaded into the cache of the processor. More precisely, the stream registers keep track of at least the lines that are in the cache, but may assume that some lines are cached which are not actually in the cache. However, forwarding some unnecessary snoop requests to the cache does not affect correctness. [0111] The heart of the stream register filter is the stream registers 700 themselves. One of these registers is updated every time the cache loads a new line, which is presented to the stream registers with appropriate control signals 716 . Logic block 704 in FIG. 13 is responsible for choosing a particular register to update based upon the current stream register state and the address of the new line being loaded into the cache in signals 716 . [0112] In operation, snoop requests received from one of the N remote processors arrive as signals 714 shown in the right-hand side of FIG. 14 . The snoop check logic 702 comprises a set of port filters that compare the addresses of the arriving snoop requests 714 with the state of the stream registers 700 to determine if the snoop requests could possibly be in the cache. If so, the requests are forwarded to queues 703 where they wait to be forwarded to the cache as actual cache snoops. The queuing structure of FIG. 13 , where each of the N remote processors has a dedicated snoop request queue 703 , is designed to allow for the maximum snoop request rate since a large number of the snoop requests will be filtered out and will never need to be enqueued. Alternative queuing structures are possible without departing from the general scope of the invention. [0113] The arbitrate and multiplex logic block 710 simply shares the snoop interface of the cache between the N snoop request queues 703 in a fair manner, guaranteeing forward progress for all requests. [0114] A description of how a single stream register is updated is now provided. A stream register actually comprises a pair of registers, the “base” and the “mask”, and a valid bit. The base register keeps track of address bits that are common to all of the cache lines represented by the stream register, while the corresponding mask register keeps track of which bits these are. The valid bit simply indicates that the stream register is in use and should be consulted by the snoop check logic 702 when deciding whether to filter a remote snoop request 714 . In order to understand the examples in the following description, consider an address space of 2 32 bytes with a cache line size of 32 bytes. In this case, a cache line load address is 27 bits in length, and the base and mask registers of the stream registers are also 27 bits in length. [0115] Initially, the valid bit is set to zero, indicating that the stream register is not in use, and the contents of the base and mask register is irrelevant. When the first cache line load address is added to this stream register, the valid bit is set to one, the base register is set to the line address, and all the bits of the mask register are set to one, indicating that all of the bits in the base register are significant. That is, an address that matches the address stored in the base register exactly is considered to be in the cache, while an address differing in any bit or bits is not. For example, given a first cache line load address is 0x1708fb1 (the 0x prefix indicates hexadecimal). Then the contents of the stream register after the load is: Base=0x1708fb1 Mask=0x7fffff Valid=1 [0117] Subsequently, when a second cache line load address is added to this stream register, the second address is compared to the base register to determine which bits are different. The mask register is then updated so that the differing bit positions become zeros in the mask. These zeros thus indicate that the corresponding bits of the base register are “don't care”, or can be assumed to take any value (zero or one). Therefore, these bits are no longer significant for comparisons to the stream register. For example, say the second cache line load address is 0x1708fb2. Then the contents of the stream register after this second load is: Base=0x1708fb1 Mask=0x7fffffc Valid=1 [0119] In other words, the second address and the base register differed in the two least significant bits, causing those bits to be cleared in the mask register. At this point, the stream register indicates that the addresses 0x1708fb0, 0x1708fb1, 0x1708fb2, and 0x1708fb3 can all be in the cache because it can no longer distinguish the two least significant bits. However, it is important to note that the two addresses which have actually been loaded are considered to be in the cache. This mechanism thus guarantees that all addresses presented to the stream register will be included within it. In the limit, the mask register becomes all zeros and every possible address is included in the register and considered to be in the cache. Clearly, the mechanism described can be used to continue adding addresses to the stream register. [0120] Every cache line load address is added to exactly one of the multiple stream registers. Therefore, the collection of stream registers represents the complete cache state. The decision of which register to update is made by the update choice logic block 704 in FIG. 13 . One possible selection criteria is to choose the stream register with minimal Hamming distance from the line load address (i.e. the stream register which will result in the minimum number of mask register bits changing to zero). Yet another selection criteria is to choose the stream register where the most upper bits of the base register match those of the line load address. Other selection criteria are possible and can be implemented without departing from the scope of the invention. [0121] In selecting a stream address register to update, the line load address is compared to all base registers combined with their corresponding mask registers in parallel. The line load address is then added to the selected stream register as described herein. [0122] The snoop check logic block 702 determines whether a snoop address 714 could possibly be in the cache by comparing it to all of the stream registers as follows: the snoop address 714 is converted to a line address by removing the low-order bits corresponding to the offset within a cache line. This line address is compared with a single stream register by performing a bitwise logical exclusive-OR between the base register and the snoop line address, followed by a bitwise logical AND of that result and the mask register. If the final result of these two logical operations has any bits that are not zero, then the snoop address is a “miss” in the stream register and is known not to be in the cache, as far as that stream register is concerned. The same comparison is performed on all of the stream registers in parallel, and if the snoop line address misses in all of the stream registers, then the snoop address is known not to be in the cache and can be filtered out (i.e. not forwarded to the cache). Conversely, if the snoop address hits in any one of the stream registers, then it must be forwarded to the cache. [0123] The snoop check logic 702 is duplicated for each of the N remote snoop request ports, but they all share the same set of stream registers 700 . [0124] Over time, as cache line load addresses are added to the stream registers, they become less and less accurate in terms of their knowledge of what is actually in the cache. As illustrated in the example above, every mask bit that becomes zero increases the number of cache lines that the corresponding stream registers specifies as being in the cache by a factor of two. In general, the problem of forwarding useless snoop requests to the processor (i.e., failing to filter them) becomes worse as the number of mask bits that are zero increases. Therefore, the stream register snoop filter are provided with a mechanism for recycling the registers back to the initial condition. This mechanism is based upon the observation that, in general, lines loaded into the cache replace lines that are already there. Whenever a line is replaced, it can be removed from the stream registers, since they only track which lines are in the cache. Rather than remove individual lines, the stream register snoop filter effectively batches the removals and clears the registers whenever the cache has been completely replaced. However, the new cache lines that were doing this replacement were also added into the stream registers, so the contents of those registers cannot simply be discarded. [0125] To solve this dilemma, the stream register snoop filter performs the following: starting with an initial cache state, stream register updates occur as described previously herein. The cache wrap detection logic block 706 is provided with functionality for monitoring cache update represented by cache update signals 717 and determining when all of the cache lines present in the initial state have been overwritten with new lines, i.e. the cache has “wrapped”. At that point, contents of all of the stream registers (call them the “active” set) are copied to a second “history” set of stream registers and the stream registers in the active set are all returned to the invalid state to begin accumulating cache line load addresses anew. In addition, the state of the cache at the time of the wrap becomes the new initial state for the purpose of detecting the next cache wrap. The stream registers in the history set are never updated. However, they are treated the same as the active set by the snoop check logic 702 when deciding whether a snoop address could be in the cache. With this mechanism, the stream registers are periodically recycled as the cache is overwritten. [0126] There are a number of ways that cache wrapping can be detected depending upon the cache update policy and the cache update signals 717 . For example, if the cache specifies the line that is overwritten, then a simple scoreboard can be used to determine the first time that any particular line is overwritten and a counter can be used to determine when every line has been overwritten at least once. Any mechanism for detecting cache wrapping can be used without departing from the scope of the invention. [0127] FIG. 14 shows an alternative embodiment of the stream register snoop filter, where the filter is entirely shared by the N remote processors. That is, the individual snoop request ports 714 do not have their own snoop check logic 702 as shown in the embodiment described with respect to FIG. 13 . In this embodiment, snoop requests are enqueued in queue structures 708 before being input to a shared snoop check logic block 701 . The queued requests are forwarded in a fair manner to the snoop check logic block 701 via an arbitrate and multiplex logic 705 . The functionality of the snoop check logic block 701 is otherwise identical to the previous stream register snoop filter check logic as described herein with respect to FIG. 13 . Clearly, alternative queuing structures 708 are possible and do not depart from the general scope of the invention. [0128] In a preferred embodiment, two sets of stream registers are used, but more than two sets can be used without departing from the scope of the invention. For example, in an embodiment implementing four sets of stream registers, two sets of active registers, A and B, and two sets of corresponding history registers, are implemented. In this embodiment, the A set of stream registers can contain information related to one subset of the cache, and the B set of stream registers can contain information related to a different subset of the cache. The partition of the cache into parts assigned to each set of stream registers, A and B, can be performed by dividing the cache into two equal parts, but other partitions may be used. Furthermore, the number of stream register sets can be more than two. For example, there can be one set of stream registers assigned to each cache set of a set-associative cache. [0129] In yet another embodiment, there can be more than one history set of stream registers, allowing the active set to be recycled more frequently. However, care must be taken to manage the history registers relative to cache wrap detections so that a register is never cleared when a cache line covered by that register could still be in the cache. One way to ensure that a register is never cleared is to add history registers to the active set of stream registers and then copy all of those history registers (and the active registers) to a second set of history registers when the cache wraps. This is essentially adding a second “dimension” of history to the preferred embodiment of the stream register snoop filter as described herein. [0130] Referring now to FIG. 15 , there is depicted a detailed process flow diagram of the control flow for the snoop filter using paired base register and mask register sets. At the start of operation, all stream registers and masks and snoop queues are reset as indicated at step 730 , and the system waits for the next snoop request from any snoop source as indicated at step 732 . When a new snoop request is received, the address of the snoop request is checked against all address stream register and masks (both sets of the stream registers) as depicted in step 734 . The address of the snoop requests is checked against all stream registers combined with accompanied masks (i.e., all address stream register and masks (both sets of the stream registers)). If the comparison of the current snoop request matches a stream register combined with the paired mask register as determined at step 736 , the snooped cache line might be in the cache and the snoop request is forwarded to the cache by placing the snoop request into snoop queue in step 740 . The process returns to step 732 to wait for the next snoop request. If, however, the snoop request does not match any stream register combined with the paired mask register in the both sets of stream registers, the snooped cache line is guaranteed not in the cache. Thus, this snoop request is filtered out in the step 738 and the process returns to step 732 . [0131] Referring now to FIG. 16 , there is depicted the control flow for updating two stream register sets and the cache wrap detection logic block for the replaced cache lines. At the start of operation, all stream registers and masks are reset and the cache wrap detection logic is cleared as indicated at step 750 , and first set of registers is activated. For each processor memory request (including either a load or store operation) that misses in L 1 cache, the address of the memory request is added to a first set of stream registers, referred to as an active address stream register set. All address stream registers from the first set of registers are checked to select the best match—as specified by the implemented register selection criteria; alternately, the first empty stream register may be selected. The address of the memory request is stored into the selected stream address register in the active register set as indicated at step 752 , and the paired mask is updated to reflect which bits of the address are relevant, and which are not. Then, at step 754 , the cache wrap detection logic is updated to reflect the new data loaded in the cache. The cache wrap detection block keeps track of whether all lines in the cache have been replaced since first use of the active registers was initiated. Thus, at step 756 , a determination is made as to whether a cache wrap condition exists. If a cache wrap condition is not detected in step 756 , the control flow loops back to the step 752 where the system waits for the next processor memory request. Otherwise, if a cache wrap condition is detected, the control continues to the step 758 where the cache wrap detection logic block is cleared and a second stream registers and masks set are cleared in the step 758 . Proceeding next to step 760 , the system waits for the next processor memory request. For the new memory request, all address stream registers from the second set of registers are checked to select the best match, e.g. , as specified by the implemented register selection criteria, for example, or, the first empty stream register is selected. The address of the memory request is stored into the selected stream address register in the second register set as indicated at step 760 , and the paired mask is updated to reflect which bits of the address are relevant. Proceeding to step 762 , the cache wrap detection logic is updated to reflect the new data loaded in the cache. As the cache wrap detection logic keeps track of all lines in the cache that have been replaced since first use of the second set of registers was initiated, a determination is then made at step 764 to determine if a cache wrap condition exists. If no cache wrap event is detected in the step 764 , the system waits for the next processor memory request by returning to step 760 . If, however, the cache wrap event is detected, the first set of registers and masks will be used again. Thus, all registers and paired masks from the first set of registers are reset, the cache wrap detection logic is cleared in the step 766 . The first set of registers are going to be used again as active for approximating the content of the cache, and the control flow is looped back to the step 752 . [0132] As described herein with respect to use of the stream register snoop filter, the power of each stream register filter to block snoop requests decreases as the number of mask bits set to zero increases. For example, if all mask bits are zero, then all snoop requests must be sent through. However, supposing these mask bits were set to zero one bit at a time (i.e., each load differs from the stream register by only one bit), then, in such a case, a snoop request for an address having exactly two bits different from the stream register would be let through, even though this address cannot be in the cache. Accordingly, additional filtering capability is provided by implementing signature filters that enable detection of more complicated, or subtle, differences such as the number of different bits. The general idea is that a snoop is forwarded from a stream register only if both the mask filter and the signature filter indicate that the address might be in the cache. [0133] Referring to FIG. 17 , there is a signature function 900 that takes as inputs, an address 901 and a stream register 902 and computes the signature 903 of the address, relative to the stream register. There are many possible signature functions, such as: [0134] 1. The number of bits in the address that are different than the stream register address. Denote this number by s. Truncation can be used to save space, e.g., set the signature to min(M,s) for some constant M. [0135] 2. If the address is N bits long, the signature is a vector of length B=(N+1) bits with zeros in every bit except for a one in bit i if s=i. To save space, this could be truncated to a vector of length B+1 (B+1<N) where there is a one in bit i if min(s,B)=i. [0136] 3. Divide the address into k (k>1) groups of bits. The length of group i is L(i) bits and let M(i)=L(i)+1. Let s(i) be the number of address bits in group i that are different than the stream register bits in group i. Then the signature is given by (s(1), s(2) . . . , s(k)), which is simply the number of different bits in each group. These groups may consist of either disjoint sets of bits, or partially overlapping sets of bits (i.e., some bit of an address is in more than one group). The length of the signature is B(1)+ . . .+B(k) bits where B(i) is the number of bits required to represent all possible values of s(i). [0137] 4. A combination of (2) and (3) above, in which the signature consists of k bit vectors corresponding to each of the groups. Bit i in group j is set to one if s(j)=i. If group i is of length L(i) bits then it requires M(i)=(L(i)+1) bits to encode all possible values of s(i). The signature is M(1)+ . . . +M(k) bits long. Truncation can be used to save space, e.g., bit i in group j is set to one if min(M,s(j))=i for some constant M. [0138] 5. As in (3) above, but there are M(1)* . . . *M(k) different unique combinations of s(1), . . . , s(k). Assign an integer q to each combination, and set the signature to a vector of all zeros except for a one in bit q. Truncation, as in (4) above, can reduce space. [0139] 6. Divide the address into k (k>1) groups of bits and let p(i) be the parity of the address bits in group i. Then the signature is given by (p(1), p(2) . . . , p(k)). [0140] 7. As in (6) above, but encode each of the 2 k combinations of parity to an integer q, and return a bit vector of length 2 k zeros, except for a one in bit q. It is understood that many other signatures are possible. [0141] If the address 901 is a load to the cache, the signature 903 is fed to a signature register updater 904 . The updater also takes the previous value of a signature register 905 as input and replaces it by a new value 906 . The appropriate way to update the signature register depends on the type of signature. Let S_old denote the old value of the signature register, S_new denote the new value of the signature register, and V denote the value of the signature 903 . Corresponding to the signature functions above, the signature updater 904 computes: [0142] 1. S_new=max(S_old,V). This keeps track of the maximum number of bits that differ from the stream register. [0143] 2. S_new=S_old bit-wise-or V. This keeps a scoreboard of the number of different bits. [0144] 3. S_new=max(S_old,V). This keeps track of the maximum number of bits in each group that differ from the stream register. [0145] 4. S_new=S_old bit-wise-or V. This keeps a scoreboard of the number of different bits in each group. [0146] 5. S_new=S_old bit-wise-or V. This keeps a scoreboard of the number of different bits in each group that occur simultaneously. [0147] 6. S_new=S_old bit-wise-or V. This keeps a scoreboard of the parity in each group. [0148] 7. S_new=S_old bit-wise-or V. This keeps a scoreboard of the parity in each group that occur simultaneously. [0149] When a snoop request comes in, its signature is computed and compared to the signature register. It a match does not occur there, the address cannot be in the cache, so the request is filtered even if the normal stream register and mask filter indicates that it might be in the cache. A snoop is forwarded only if the signature register and mask register both indicate that the address might be in the cache. [0150] The signature filtering mechanism is shown in FIG. 18 . A load address 1001 to the cache is sent to the mask update logic 1002 which operates as described earlier, taking the previous mask register 1003 , a stream register 1004 and updating the mask register 1003 . This address 1001 is also fed to a signature function 1005 that also takes the stream register 1004 as input and produces a signature 1006 . The signature 1006 and previous signature register 1008 are fed to the signature update logic 1007 that creates a new value for the signature register 1008 . [0151] When a snoop address 1009 a request comes in, it is received and processed by the mask filter 1010 producing a mask snoop request 1011 . In addition, this same snoop address (shown as 1009 b ) and the stream register 1004 are fed to the signature function 1012 producing a signature 1013 . Note that the signature functions 1005 and 1012 must be identical logic, meaning that if they have the same inputs they will produce the same outputs. The signature of the snoop request 1013 and the signature register are fed to the signature filter 1014 . [0152] This filter must determine if a request having this signature might be in the cache and its exact operation depends on the type of signature. In the case of the “scoreboard” types of signature updaters, the snoop signature is bit-wise and-ed with the signature register. If the result of this is non-zero, then a signature snoop request 1015 is made (i.e., that signal is set to 1 if a request is to be made and 0 otherwise). In the case of “maximum number of bits changed” types of signature updaters, a check is made to see if the snoop signature is less than or equal to the signature register (one comparison for each group). If all such comparisons are true, the address might be in the cache and the signature snoop request 1015 is made. The mask snoop request 1011 and the signature snoop request 1015 are AND-ed together in logic element 1016 to generate a snoop request signal 1017 . If this signal is 1, a snoop request will be generated unless it is ruled out by the snoop vector lists, or an applied range filter (see FIG. 7 ). However, specifically, such a snoop request cannot be ruled out by the result of a signature-mask filter from another stream register. [0153] The signature register is set appropriately at the same time that the stream register is first set, or reset. For scoreboard types and max-types of signatures, the signature register is set to all zeros (indicating no bits different from the stream register). [0154] The stream register filter relies upon knowing when the entire contents of a cache have been replaced, relative to a particular starting state-a cache wrap condition as referred to herein. A set-associative cache is considered to have wrapped when all of the sets within the cache have been replaced. Normally, some sets will be replaced earlier than others and will continue to be updated before all sets have been replaced and the cache has wrapped. Therefore, the starting point for cache wrap detection is the state of the cache sets at the time of the previous cache wrap. [0155] In one embodiment, the cache is set-associative and uses a round-robin replacement algorithm, however other replacement implementations are possible. For instance, cache wrap detection may be achieved when the cache implements an arbitrary replacement policy, including least-recently-used and random. As referred to in the description to follow, a set-associative (SA) cache comprises some number of sets, where each set can store multiple lines (each with the same set index). The lines within a set are called “ways”. Hence, a 2-way set associative cache has two (2) lines per set. All of the ways within a set are searched simultaneously during a lookup, and only one of them is replaced during an update. Furthermore, a set can be partitioned such that a subset of the ways is assigned to each partition. For example, a 4-way SA cache may be partitioned into two 2-way SA caches. The virtual memory page table (and the translation lookaside buffer (TLB)) can provide a partition identifier that specifies which cache partition a particular memory reference is targeted at (both for lookup and update). The register that stores the way to be updated for a cache wrap needs to be big enough to store a way number. For example, 2 bits for a 4-way SA cache, or 5 bits for a 32-way SA cache. There is one such register per set because each set can wrap at a different time. [0156] In one embodiment of the invention, the cache is partitionable into three partitions, with each partition including a contiguous subset of the cache ways, and that subset is the same within each cache set. Memory references are designated by the processor's memory management unit to be cached in one of the three partitions. Updates to a partition occur independently of the other partitions, so one partition can wrap long before the entire cache wraps. However, detecting the wrapping of a partition is identical to detecting the wrapping of the entire cache when the partition being updated is known. Thus, as referred to hereinafter, cache wrapping includes either partition wrapping or entire cache wrapping. [0157] In order for external logic to detect cache updates, a cache must provide an indication that an update is occurring and which line is being overwritten. The logic of the preferred embodiment assumes that this information is provided by means of a set specification, a way specification and an update indicator. [0158] FIGS. 19 ( a ) and 19 ( b ) depict the cache wrap detection logic of the preferred embodiment for an N-way set-associative cache. In this embodiment, it is assumed that updates to a set are always performed in round-robin order. That is, the “victim” way chosen to be overwritten is always the one following the previously-overwritten one. [0159] FIG. 19 ( a ) particularly depicts one embodiment of logic implemented for detecting the wrap of a single partition of a single set (set “i” in the embodiment depicted) within the logic block 920 . When this logic has detected a wrap in set i, it asserts the set_wrap(i) signal 910 . FIG. 19 ( b ) shows how the individual set_wrap(i) 910 signals from all N sets of the cache are combined with a logic OR function to produce the cache_wrap 912 signal, which asserts when the entire cache (i.e. all sets) have wrapped. It is understood that the logic and circuitry depicted in FIGS. 19 ( a ) and 19 ( b ) is only one example implementation and skilled artisans will recognize that many variations and modifications may be made thereof without departing from the scope of the invention. [0160] On the left-hand side of FIG. 19 ( a ), there is depicted a partition detection logic block 922 that determines when a cache update falls within the partition that is being monitored for wrapping. This logic assumes that the partition extends from a way specified by “lower” 916 to the way specified by “upper” 918 . Therefore, the remainder of the logic that detects set wraps partition only changes state when there is an update, and that update falls within the partition of interest. Note that the partition detection logic 922 is common to all N copies of the set wrap detection logic. [0161] Within the set wrap detection logic, the common partition update indicator is further qualified to act only when the update is to the particular set i associated with that logic. This is done by matching the set specifier 924 to the index of the set wrap detection logic 926 . [0162] The remainder of the logic circuits function as follows: Assume that initially, the flip-flop driving set_wrap(i) 930 is clear, indicating that the set has not wrapped, and the register 928 includes the way that must be updated to complete a set wrap. In this state, the register retains its value. When a cache update occurs, where the way 914 matches the contents of the register 928 , as determined by a comparator device 919 , the flip-flop driving set_wrap(i) 930 is loaded with logic 1, causing set_wrap(i) 910 to assert. Thereafter, cache updates cause the updated way 914 to be stored in the register 928 , so the register 928 effectively tracks those updates. When all cache sets have wrapped, the combined cache_wrap 912 signal is asserted as shown in FIG. 19 ( b ), causing the flip-flop 930 to clear (assuming Reset takes precedence over Load). This returns the circuit to the initial state, with the register 928 storing the way that must be updated to indicate the next set wrap. [0163] It is thus understood that there is one register per set that stores the number of a way and when that way is overwritten, then the set has wrapped. However, the sets wrap at different times (depending on the access pattern), and the entire cache is not considered to have wrapped until all sets have wrapped. At that point, the state of the victim way pointers (i.e. pointer to the last way that was overwritten; one per set) becomes the new initial condition for detecting the next cache wrap. The first embodiment accommodates this requirement by having the register described above keep track of ways that are overwritten between the time that it has wrapped and the time that the entire cache has wrapped. Then when the whole cache wraps, it stops tracking the overwritten ways and becomes the basis for comparison for determining when the set wraps again. [0164] In a second embodiment of the cache wrap detection logic, a counter is implemented, so when the whole cache wraps, all set counters are reset to the number of ways in the partition. As ways are overwritten, the counters count down; and when a counter reaches zero, then the corresponding set has wrapped. When all counters reach zero, then the cache has wrapped and the process starts again. [0165] According to this second embodiment, the set wrapped detection logic provided within the box 920 depicted in FIG. 19 ( a ) is thus based on a loadable counter, rather than a register and comparator. This logic is shown in FIG. 20 . In this logic, a down-counter device 932 is loaded with the number of ways in the partition 936 while set_wrap(i) 910 is asserted (assuming Load takes precedence over Down). When all sets have wrapped and cache_wrap 912 is asserted, the flip-flop 930 driving set_wrap(i) is cleared and the counter 932 is no longer loaded. Thereafter, each update to the partition 914 and set 934 tracked by the logic cause the counter 932 to count down by one. Once it reaches zero, the flip-flop 930 is loaded with logic 1, causing set_wrap(i) 910 to be asserted, and returning the logic to the initial state. [0166] A third embodiment of the cache wrap detection logic, shown in FIG. 2l , will work with a cache that implements any replacement policy, including least recently used and random. In this case, a scoreboard 940 is used to keep track of the precise cache way 914 that is overwritten. Specifically, it is used to detect the first write to any way. In addition, a counter 942 keeps track of the number of times that a scoreboard bit was first set (i.e. goes from 0 to 1). It does this by only counting scoreboard writes where the overwritten bit (old_bit) is zero. The counter 942 is pre-loaded to the partition size 936 (i.e. number of ways in the partition), so once this counter reaches zero, the entire cache partition has wrapped. This is indicated by the cache_wrap 912 signal being asserted, causing the counter 942 to be reloaded (assuming Load takes precedence over Down) and the scoreboard 940 to be cleared (i.e. reset). [0167] While the preferred embodiment of the present invention is practiced in conjunction with a write-through cache, wherein snooping only occurs on write requests, and the results of a snoop action are the invalidation of a local data copy, the invention is not so limited. For instance, the invention can also be practiced in conjunction with write-back cache organizations. In accordance with a write-back cache, a coherence protocol will include additional transactions, e.g., including but not limited to, those in accordance with the well-known MESI protocol, or other coherence protocols. In accordance with a coherence protocol for writeback caches, read transaction on remote processors cause snoop actions to determine if remote caches have the most recent data copy in relation to the main memory. If this is the case, a data transfer is performed using one of several ways, including but not limited to, causing the processor having the most recent data to write the data to main memory, directly transferring the data from the owner of the most recent copy to the requestor, or any other method for transferring data in accordance with a snoop intervention of a specific protocol. In accordance with this invention, a snoop filtering action can be used to determine an accelerated snoop response. [0168] While the preferred embodiments have been described in terms of fixed interconnection topologies, and fixed snoop filtering operations, in one aspect of the present invention the snoop filtering subsystem has programmable aspects at one, or more, levels of the snoop filter hierarchy. In accordance with one embodiment of a programmable feature of the present invention, the interconnect topology is selected. In accordance with one variety of programmable topology, the one-to-one and one-to-many relationship between different filters in a topology is selectable. In accordance with another aspect of a programmable embodiment, the order in which a first snoop filter, and then a second snoop filter is accessed, or alternatively, a first or second snoop filter are accessed in parallel, is configurable under program control. [0169] In accordance with yet another aspect of yet another embodiment of a programmable feature of the present invention, the operation of a filter subunit is programmable. This can be in the form of configurable aspects of a snoop filter, e.g., by configuring programmable aspects such as associativity of the cache being snooped, the coherence architecture being implemented, and so forth. In another aspect of a programmable filter subunit, the filter subunit is implemented in programmable microcode, whereby a programmable engine executes a sequence of instructions to implement the aspects of one or more preferred embodiments described herein. In one aspect, this is a general microcode engine. In another aspect, this is an optimized programmable microcode engine, the programmable microcode engine having specialized supporting logic to detect snoop filter-specific conditions, and, optionally, specialized operations, such as “branch on cache wrap condition”, specialized notification events, e.g., in the form of microcode engine-specific exceptions being delivered to the microcode engine, such as “interrupt on cache wrap condition”, and so forth. [0170] In yet another embodiment of a programmable feature of the present invention, parts or all of the aspects of snoop filtering are implemented incorporating a programmable switch matrix, or a programmable gate array fabric. In one of these aspects, the routing between snoop subunits is performed by configuring the programmable switch matrix. In another aspect of this programmable embodiment, the actions of the snoop filter unit are implemented by configuring a programmable gate array logic block. In anther aspect of the present invention, the entire snoop filter block is implemented by configuring at least one field-programmable gate array cell. [0171] In accordance with another embodiment of a programmable feature of the present embodiments, one of more snoop filter subsystems can be disabled, certain snoop filtering steps can be bypassed, or snoop filtering can be disabled altogether. In one embodiment, this is achieved by writing the configuration of the snoop filter in a configuration register. In another embodiment, this configuration can be selected by input signals. [0172] While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.

A method and apparatus for supporting cache coherency in a multiprocessor computing environment having multiple processing units, each processing unit having one or more local cache memories associated and operatively connected therewith. The method comprises providing a snoop filter device associated with each processing unit, each snoop filter device having a plurality of dedicated input ports for receiving snoop requests from dedicated memory writing sources in the multiprocessor computing environment. Each snoop filter device includes a plurality of parallel operating port snoop filters in correspondence with the plurality of dedicated input ports, each port snoop filter implementing one or more parallel operating sub-filter elements that are adapted to concurrently filter snoop requests received from respective dedicated memory writing sources and forward a subset of those requests to its associated processing unit.

This is a continuation-in-part of U.S. patent application Ser. No. 07/855,028 filed 12th Jun. 1992, now abandoned, and U.S. patent application Ser. No. 08/086,996 filed 7th Jul. 1993, U.S. Pat. No. 5,446,145, each of which is a continuation-in-part of U.S. patent application Ser. No. 07/468,107 filed 19th Jan. 1990 and granted Jan. 25th, Jan. 1994 as U.S. Pat. No. 5,281,704. FIELD OF THE INVENTION The present invention relates to dichelants, that is chelating agents capable of complexing two metal ions simultaneously, and to chelates and salts thereof and their use in diagnostic and therapeutic compositions, especially as contrast enhancing agents in diagnostic medical imaging. BACKGROUND OF THE INVENTION The medical use of chelants is now well established, for example as stabilisers for pharmaceutical preparations, as antidotes for poisonous heavy metal species, as carriers for diagnostically or therapeutically useful metal ions, for example in contrast media for use in magnetic resonance, X-ray or ultrasound imaging or in scintigraphy. For such diagnostic agents, it is generally important that the chelate complexes should be stable both kinetically and thermodynamically and for this reason there has been much interest in the macrocyclic polyamine-based chelates, in particular DOTA and its derivatives and analogues, which form very stable complexes with the lanthanide metal ions such as gadolinium and dysprosium which are favoured diagnostic metal ions for magnetic resonance imaging due to their relatively large effects on the relaxation times (e.g. T 1 and T 2 * ) of neighbouring water protons. The paramagnetic lanthanide metal ions useful as MR imaging contrast agents are relatively toxic and for clinical use must be administered in a form which allows little or no release of the metal for subsequent biological uptake and retention. For this reason, from the early years of MR contrast agents, the use of stable chelate complexes has been proposed. Thus the first commercial lanthanide based MR imaging contrast agent, Magnevist, contained GdDTPA, a complex with a high stability constant which following parenteral administration is excreted relatively rapidly by glomerular filtration with the gadolinium still in the chelate complex. GdDOTA has an even higher pK HL and thus was also a prime candidate for consideration as an MR imaging contrast agent. DOTA (1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid) and HPDO3A (1-(2-hydroxypropyl)-4,7,10-tetraazacyclododecane-N,N',N"-triacetic acid) have indeed been proposed as chelants for MR imaging contrast agents and GdDOTA and GdHPDO3A have been commercially developed by companies active in this field. The lanthanide metals generally have a stable +3 oxidation state and DOTA with its four carboxylic acid groups results in a charged complex, i.e. GdDOTA - , requiring a counterion. Analogous uncharged complexes may be produced by eliminating one of DOTA's nitrogen-attached carboxymethyl groups or by replacing it by a non-ionizing group, i.e. by using a chelant such as DO3A (1,4,7,10-tetraazacyclododecane-N,N',N"-triacetic acid) or HPDO3A. Contrast media based on such non-ionic, or overall charge neutral, complexes have lower osmolalities for a given metal ion concentration and can demonstrate other improved properties relative to the analogous charged complexes. Moreover, the ring nitrogen "freed" by removal of the carboxymethyl group in moving from DOTA to DO3A can of course be substituted by groups which can act to enhance the hydrophilicity or lipophilicity or other biodistribution affecting properties of the chelate. Recently, there has been growing interest in the use of chelants capable of chelating more than one metal ion per chelant molecule as carriers for paramagnetic or heavy metal ions for MR or X-ray imaging contrast agents. These polychelants offer several advantages over the monochelants such as DTPA, DO3A or DOTA. Thus for example, the osmolality at a given metal concentration can be reduced still further, the simultaneous delivery of a plurality of metal ions to a target site can be facilitated, and more efficient contrast agents can be produced. Polychelants range from dichelants through oligochelants to true polychelants having perhaps hundreds of chelant moieties per molecule. Many such compounds have been described but there is still a need for polychelants, and in particular oligochelants and especially dichelants, having improved properties in terms for example of relaxivity, stability, biodistribution, biotolerability, viscosity, solubility and osmolality. Particular macrocyclic dichelants described in the literature include the DO3A dimers of formula II, III and IV whose preparation has been described by Schering AG in EP-A-255471 and EP-A-485045 (U.S. Pat. No. 5,277,895) and elsewhere. ##STR2## (described by Schering AG in EP-A-255471 and in a poster presented at the European Congress of NMR in Medicine and Biology at Strasbourg in May 1990) ##STR3## (described by Schering AG in EP-A-255471) ##STR4## (described by Schering AG in EP-A-485045 (U.S. Pat. No. 5,277,895). All of these macrocyclic chelant dimers have the general formula DO3A'-L-DO3A' where DO3A' is a ring nitrogen deprotonated DO3A residue and L is a linker group. With lanthanides such as gadolinium, these macrocyclic dimers will produce non-ionic dichelates and these compounds have been found to possess high relaxivity. Thus for example the T1 relaxivities of the bisgadolinium chelates of the compounds of formula II are almost double the T1 relaxivity of GdDO3A. SUMMARY OF THE INVENTION We have now found that dichelant compounds having improved properties are produced if the linker groups incorporate ester or amide functionalities, and especially where the linkers comprise carbonyl-attached alkylene groups in which two or more of the methylene groups are replaced by nitrogen or oxygen atoms. Thus viewed from one aspect the invention provides a polychelant of formula Va A--L--A (Va) (where each A which may be the same or different is a macrocyclic chelant moiety and L is a linker moiety incorporating at least one amide or ester bond in the atom chain linking the two chelant groups A) or a salt or chelate thereof. Conveniently the A--L bonds in the compounds of formula Va will be of formula A'--CO--X * --L' where X * is oxygen or a secondary or tertiary or ring nitrogen, ie. the carbonyl function in the amide or ester bond will conveniently be to the chelant side of the bond. Thus linker compounds useful for the production of dimeric chelants ALA include, but are not limited to diamine or diol compounds such as 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, N,N'-dimethyl-1,2-diaminoethane, N,N'-dimethyl-1,3-diaminopropane, 1,4-diaminocyclohexane, 1,4-phenylenediamine, diethylenetriamine, triethylenetetraamine, piperazine, 1,4-diazacycloheptane, 1,5-diamino-3-oxapentane, 1,8-diamino-3,6-dioxaoctane, 1,11-diamino-3,6,9-trioxaundecane, 1,7-diaza-4,10,13-trioxapentadecane and 2,2-dimethyl-1,3-propanediol. Preferably the compounds of the invention are polychelants of formula Vb ##STR5## (wherein each X which may be the same or different is NZ, O or S, at least two Xs being NZ; each Z is a group R 1 or a group CR 1 2 Y, at least one Z, and preferably 2 or 3 Zs, on each macrocyclic ring being a group CR 1 2 Y; each Y is a group CO 2 H, PO 3 H, SO 3 H, CONR 1 2 , CON(OR 1 )R 1 , CNS or CONR 1 NR 1 2 , preferably COOH; m is 0 or 1 or 2, preferably 1; each n is 2 or 3, preferably 2; q is 1 or 2, preferably 1; each R 1 which may be the same or different is a hydrogen atom or an alkyl group optionally substituted by one or more hydroxy and/or alkoxy groups; and D is a bridging group having a molecular weight of less than 1000, preferably less than 500, joining two macrocyclic rings via at least one amide or ester bond) and salts and metal chelates thereof. Viewed from a further aspect, the present invention provides a diagnostic or therapeutic agent comprising a metal chelate, whereof the chelating entity is the residue of a compound according to the present invention, together with at least one pharmaceutical or veterinary carrier or excipient, or adapted for formulation therewith or for inclusion in a pharmaceutical formulation for human or veterinary use. Viewed from another aspect, the present invention provides a detoxification agent comprising a chelating agent according to the invention in the form of a weak complex or salt with a physiologically acceptable counterion, together with at least one pharmaceutical or veterinary carrier or excipient, or adapted for formulation therewith or for inclusion in a pharmaceutical formulation for human or veterinary use. Viewed from a further aspect, the present invention provides a method of generating enhanced images of the human or non-human animal body, which method comprises administering to said body an effective amount of a diagnostic agent comprising a metal chelate of compound of formula V (ie. Va or Vb), or a salt thereof, and generating an image of at least part of said body to which said chelate distributes, wherein said metal is paramagnetic, radioactive or X-ray opaque. Viewed from a further aspect, the present invention provides a method of radiotherapy practised on the human or non-human animal body, which method comprises administering to said body an effective amount of a chelate of a radioactive metal species with a chelating agent of formula V, or a salt thereof. Viewed from a further aspect, the present invention provides a method of heavy metal detoxification practised on the human or non-human animal body, which method comprises administering to said body an effective amount of a chelating agent of formula V or a physiologically tolerable salt or weak complex thereof. Viewed from a still further aspect, the present invention provides a process for the preparation of the metal chelates of the invention which process comprises admixing in a solvent a compound of formula V or a salt (e.g. the sodium salt) or chelate thereof together with an at least sparingly soluble compound of said metal, for example a chloride, oxide, acetate or carbonate. DETAILED DESCRIPTION In the compounds of the invention, the macrocyclic ##STR6## rings preferably have 9 to 14 ring atoms, the ring heteroatoms especially preferably being either all nitrogen or being one oxygen and three nitrogens. The alkylene ring segments (CR 1 2 ) n preferably are all (CR 1 2 ) 2 groups or in the case of an N 4 macrocycle the alkylene segments may alternatively be alternating (CR 1 2 ) 3 and (CR 1 2 ) 2 groups. Thus the preferred macrocyclic skeletons are those of formulae VI ##STR7## The bridging group D is conveniently a group of formula ##STR8## where p is 0 or 1, X 2 is O or NR 2 , R 2 is a hydrogen atom or a hydroxy, OR 1 or NR 1 2 group or an alkyl group optionally interrupted by oxygen, sulphur or nitrogen atoms or by carbonyl or aryl groups and optionally substituted by hydroxyl, amine or aryl groups, or R 2 contains a functional group for attachment to a biomolecule or macromolecule, or two R 2 groups together form a bridging linker group, e.g. a group L 1 , and L 1 which provides a chain of at least two atoms linking two X 2 groups or at least one atom linking an X 2 group and a (CR 1 2 ) q moiety, is a straight chain, branched or cyclic alkylene group or a combination of such groups, optionally substituted and optionally being interrupted by oxygen, sulphur or nitrogen atoms or by aryl or carbonyl groups. The linker group L 1 will preferably be a linear, branched or cyclic alkylene group or a combination thereof or a combination of arylene and alkylene groups, for example providing a linking backbone 1 to 50 atoms long but preferably 2 to 25, and especially 2 to 10 atoms long in total on any one unbranched segment. The carbon backbone in such linker groups may be interrupted by heteroatoms such as nitrogen, oxygen and sulphur, and may carry bridging groups, thereby creating homo- or heterocyclic rings within the linker group. Where this occurs, the rings created will preferably be 3 to 12, especially 5 to 8 and, particularly, 6 membered rings. Moreover the rings and the linear segments of the linker group may optionally be unsaturated and may optionally carry one or more substituents selected from alkyl, hydroxy, alkoxy, amine, aryl and substituted aryl groups as well as non-hydrogen R 1 groups or additional chelating groups, eg. Y groups especially carbonyl and SO 3 H groups, and groups such as for example long chain (eg. C 10-20 ) alkyl, aryl or polyaryl groups which are suitable for liposomal incorporation of the compound of formula V or groups, such as isothiocyanate groups, for attachment of the compound of formula V to a biomolecule, polymer, dendrimer or other macromolecule, for example to create a bifunctional chelant. The bridging group D in the compounds of the invention may, as indicated above, serve to link together two chelant moieties, thereby holding together the dichelate structure. Besides filling this role as linker or spacer of chelant sites, the bridging group can be so selected as to yield a product having other desired characteristics. For example it is possible to increase hydrophilicity, lipophilicity, or tissue specificity of the end product by attaching to or incorporating within the bridging group, groups which are hydrophilic, lipophilic, or tissue targeting. In this way, the overall charge of the chelate structure, or the overall lipophilicity, or tissue targeting can be controlled. In the compounds of formula V, alkyl moieties preferably have 1 to 6, especially 1 to 4 carbon atoms unless otherwise specified, and aryl moieties are preferably phenyl groups. Particularly preferred compounds of formula V include those of formula VII M--CH.sub.2 CO).sub.2 --D' (VII) where M is a nitrogen attached triaza, tetraaza, triazaoxa or triazathia-cycloalkane of formula VI having at least one and preferably two ring nitrogens substituted by C 2 COOH groups and having any remaining ring nitrogen substituted by a group R 3 , M preferably being a group of formula VI having two or more, preferably three, ring heteroatoms substituted by CH 2 COOH groups; R 3 (which for tetraheteroatom rings is preferably at the ring heteroatom remote from the ring attachment nitrogen) is a hydrogen atom, or an alkyl group optionally mono or polysubstituted by hydroxyl or alkoxy groups (eg, hydroxyalkyl, polyhydroxyalkyl, alkoxyalkyl, polyalkoxyalkyl, hydroxyalkoxyalkyl, hydroxypolyalkoxyalkyl, polyethylene glycol etc.) and optionally interrupted by arylene or substituted arylene groups; and CO--D'--CO is a bridging group D as discussed above. Preferred bridging groups D in the dichelant compounds of the invention include those of the formulae: ##STR9## where r is an integer having a value of 1 to 6, especially 1, 2 or 3, and s is an integer having a value of 1 to 20, especially 1 to 15. Especially preferred are bridging groups containing ether oxygens, for example COOCH 2 CH 2 OCH 2 CH 2 NHCH 2 CH 2 OCH 2 CH 2 OCO, as these may be associated with particularly low toxicity. Preferred compounds according to the invention also include the polyhydroxylated dichelants, e.g. where D or R 1 groups are hydroxylated, as they can present a better toxicity profile than their non-hydroxylated counterparts. Lipophilic analogs are also of interest due to the potential for increased liver uptake; moreover the long chain lipophilic analogs have the ability to be incorporated into liposomes for use as blood pool agents and for targetted delivery to specific organs or tissues. Indeed chelate compounds according to the invention, in particular the lipophilic analogs, are of particular interest as blood pool agents where they exhibit prolonged plasma half lifes. The compounds of the invention may be prepared by conventional synthetic techniques, conveniently starting from the corresponding N-unsubstituted or N-carboxymethylated polyazacycloalkanes, condensing these to a bifunctional linker molecule, generally after protection of one or more of the ring nitrogens or N-carboxymethyl groups, followed by deprotection and if required introduction of functional groups at the ring nitrogens. Where the dichelant is asymmetrical, it can of course be constructed by conjugating one macrocycle to a monoprotected bifunctional linker molecule, deprotecting, and conjugating a second macrocycle to the macrocycle-linker intermediate. For such purposes, the bifunctional linker molecule may of course itself be asymmetric to allow one end to conjugate directly to a macrocycle ring nitrogen and the other to conjugate to a macrocycle side chain, e.g. a carboxymethyl group or a reactive derivative thereof. Thus viewed from a further aspect the invention also provides a process for the preparation of the compounds of the invention, said process comprising at least one of the following steps: (a) reacting a compound of formula V wherein at least one group X is a group NH, with a compound of formula VIII Lv--R.sup.4 (VIII) (where Lv is a displaceable leaving group, for example a halogen atom or a substituted sulphonyloxy group, such as chlorine, bromine, iodine, methanesulphonyloxy, phenysulphonyloxy or p-toluenesulphonyloxy groups) and R 4 is a group CR 1 2 Y or group R 1 other than hydrogen); (b) reacting compounds of formulae X and/or XI ##STR10## (wherein X, R 1 , n, q and m are as hereinbefore defined) or an activated derivative, e.g. halide, thereof with a linker molecule of formula IX ##STR11## (wherein X 2 and L 1 are as hereinbefore defined, t is 0 or 1, and each Lv is a displaceable leaving group, one optionally being protected prior to conjugation of the second compound of formula X or XI); (c) metallating or transmetallating a compound of formula V or a chelate thereof; (d) converting a compound of formula V or a chelate thereof into a base or acid addition salt thereof or converting a salt into the free acid or base; and (e) performing at least one of steps (a) to (c) above using reagents with protected functional groups and subsequently removing the protecting groups. The starting compounds of formulae VIII, IX, X and XI are either known from the literature or can be produced by conventional synthetic techniques. The starting compounds of formula VIII used in step (a) can be prepared by the process of step (b). As indicated above, during the reaction, functional groups present in the starting materials but not involved in the particular process steps may be protected, for example to avoid unwanted substitution or polymerisation. Conventional protection and deprotection techniques may be used (see for example "Protective Groups in Organic Synthesis" by T. W. Greene, Wiley-Interscience, N.Y., 1981 and "Protective Groups in Organic Chemistry" by J F W McOmie, Plenum, London, 1973). Suitable protecting groups for carboxyl groups include ester functions, for ring nitrogens alkyl, borane or organometallic functions, for hydroxyl groups acyl functions. The protecting groups will be removed by standard techniques, for example hydrolysis, hydrogenolysis, etc. after the reactions step is complete. Salt and chelate formation may be effected by conventional techniques, e.g. as described in the above mentioned patent publications. The skeletons of the macrocyclic chelant groups or, more preferably, of the linker moiety, may be derivatised to enhance properties of the overall chelant, for example to include hydrophilic or lipophilic groups or biologically targetting groups or structures. Examples of macromolecules, biomolecules and macrostructures to which the polymeric chelant may be conjugated in this way include polymers (such as polylysine or polyethyleneglycol), dendrimers (such as first to sixth generation starburst dendrimers and in particular PAMAM dendrimers), polysaccharides, proteins, antibodies or fragments thereof (especially monoclonal antibodies or fragments such as Fab fragments), glycoproteins, proteoglycans, liposomes, aerogels, peptides, hormones, steroids, microorganisms, human or non-human cells or cell fragments, cell adhesion molecules (in particular nerve adhesion molecules such as are described in WO-A-92/04916), other biomolecules, etc). Generally such derivatisation will be achieved most conveniently by the introduction of alkyl- or aralkyl-carried functions, to which the macromolecule, biomolecule, etc. can be bound either directly or via a linker molecule, for example a bi- or polyfunctional acid, activated acid or oxirane. In the case of conjugation to dendrimers, the dendrimer carriers can be produced by standard techniques, for example as described by Tomalia and by Nycomed Salutar in Angew Chem Int Ed Eng 29:138 (1990), WO-A-88/01178, WO-A-90/12050 and WO-A-93/06868 and the references cited therein. Such macromolecular derivatives of the compounds of formula V and the metal chelates and salts thereof form a further aspect of the present invention. The linkage of a compound of formula V to a macromolecule or backbone polymer may be effected by the methods of Nycomed Salutar (WO-A-90/12050) or by any of the conventional methods such as the carbodiimide method, the mixed anhydride procedure of Krejcarek et al. (see Biochemical and Biophysical Research Communications 77: 581 (1977)), the cyclic anhydride method of Hnatowich et al. (see Science 220: 613 (1983) and elsewhere), the backbone conjugation techniques of Meares et al. (see Anal. Biochem. 142: 68 (1984) and elsewhere) and Schering (see EP-A-331616 for example) and by the use of linker molecules as described for example by Nycomed imaging in WO-A-89/06979 (U.S. Pat. No. 5,208,324). Salt and chelate formation may be performed in a conventional manner. The chelating agents of formula V may be used in detoxification or in the formation of metal chelates, chelates which may be used for example in or as contrast agents for in vivo or in vitro magnetic resonance (MR), X-ray or ultrasound diagnostics (e.g. MR imaging and MR spectroscopy), or scintigraphy or in or as therapeutic agents for radiotherapy, and such uses of these metal chelates form a further aspect of the present invention. Salts or chelate complexes of the compounds of the invention containing a heavy metal atom or ion are particularly useful in diagnostic imaging or therapy. Especially preferred are salts or complexes with metals of atomic numbers 20-32, 42-44, 49 and 57 to 83, especially Gd, Dy and Yb. For use as an MR-diagnostics contrast agent, the chelated metal species is particularly suitably a paramagnetic species, the metal conveniently being a transition metal or a lanthanide, preferably having an atomic number of 21-29, 42, 44 or 57-71. Metal chelates in which the metal species is Eu, Gd, Dy, Ho, Cr, Mn or Fe are especially preferred and Gd 3+ , Mn 2+ and Dy 3+ are particularly preferred. Chelates of ions of these metals specifically listed above with chelants of formula V or their salts with physiologically tolerable counterions are particularly useful for the diagnostic imaging procedures mentioned herein and they and their use are deemed to fall within the scope of the invention and references to chelates of compounds of formula V herein are consequently to be taken to include such chelates. The bislanthanide complexes of the compounds of formula V are especially preferred. For diagnostic imaging purposes it is particularly important that the metal chelate complex be as stable as possible to prevent dissociation of the complex in the body. In magnetic resonance imaging (MRI) it is frequently desirable to be able to target certain organs or tissues. In particular there is a need for improved hepatobiliary imaging MR contrast agents. Chelates of paramagnetic metals with compounds of formula V carrying one or more lipophilic groups are particularly suited for use as hepatobiliary MR contrast agents, since the presence of the lipophilic group will promote uptake by hepatocytes. By linking the lipophilic group to the molecule via a readily hydrolysable linking group such as an ester, the reabsorption after excretion to the intestine can be prevented. The paramagnetic metal chelates of compounds of formula I, especially the chelates of high spin metal ions such as Gd 3+ and more especially Dy 3+ , are particularly suitable for use as magnetic susceptibility (MS) contrast agents (T 2 or T 2 * contrast agents) in MR imaging and other MR investigations. The use of paramagnetic metal mono-chelates is discussed by Villringer et al. in Mag. Resort. Med. 6:164-174 (1988) and by Kucharczyk et al. in U.S. Pat. No. 5,190,744 and WO-A-91/14186. Using the dimeric chelates of the present invention, smaller volumes of contrast medium can be administered to achieve the same MS effect thus allowing for more effective bolus dosing. Moreover, while for monochelates high susceptibility paramagnetic centres such as Dy(III) generally have to be used in MS studies, by using the dimeric chelates of the invention a wider range of paramagnetic metal centres, including in particular Gd(III) become useful. For certain hepatobiliary imaging purposes it is desirable that the lipophilic contrast agent be precipitated as particles which can be taken up by Kupffer cells in the liver. In such cases it is preferred to use chelates of Dy 3+ with lipophilic compounds of formula V in conjunction with an imaging system utilising the magnetic susceptibility properties of the contrast agent; Kupffer cells in the liver are scarce and the contrast achievable using chelates with the gadolinium normally used in conventional MR imaging (i.e. as a T 1 relaxation agent) is generally insufficient. Such magnetic susceptibility agents form an important embodiment of the invention. For use as contrast agents in MRI, the paramagnetic metal species is conveniently non-radioactive as radioactivity is a characteristic which is neither required nor desirable for MR-diagnostic contrast agents. For use as X-ray or ultrasound contrast agents, the chelated metal species is preferably a heavy metal species, for example a non-radioactive metal with an atomic number greater than 37, preferably greater than 50, e.g. Dy 3+ . For use in scintigraphy and radiotherapy, the chelated metal species must of course be radioactive and any conventional complexable radioactive metal isotope, such as 99m Tc, 67 Ga or 1ll In for example, may be used. For radiotherapy, the chelating agent may be in the form of a metal chelate with for example 153 Sm, 67 Cu or 90 Y. For use in detoxification of heavy metals, the chelating agent should be in salt form with a physiologically acceptable counterion, e.g. sodium, calcium, ammonium, zinc or meglumina, e.g. as the sodium salt of the chelate of the compound of formula V with zinc or calcium. Where the metal chelate carries an overall charge, such as is the case with the prior art Gd DTPA, it will conveniently be used in the form of a salt with a physiologically acceptable counterion, for example an ammonium, substituted ammonium, alkali metal or alkaline earth metal (e.g. calcium) cation or an anion deriving from an inorganic or organic acid. In this regard, meglumine salts are particularly preferred. The diagnostic and therapeutic agents of the present invention may be formulated with conventional pharmaceutical or veterinary formulation aids, for example stabilizers, antioxidants, osmolality adjusting agents, buffers, pH adjusting agents, etc. and may be in a form suitable for parenteral or enteral administration, for example injection or infusion or administration directly into a body cavity having an external escape duct, for example the gastrointestinal tract, the bladder or the uterus. Thus the agent of the present invention may be in a conventional pharmaceutical administration form such as a tablet, capsule, powder, solution, suspension, dispersion, syrup, suppository, etc; however, solutions, suspensions and dispersions in physiologically acceptable carrier media, for example water for injections, will generally be preferred. The compounds according to the invention may therefore be formulated for administration using physiologically acceptable carriers or excipients in a manner fully within the skill of the art. For example, the compounds, optionally with the addition of pharmaceutically acceptable excipients, may be suspended or dissolved in an aqueous medium, with the resulting solution or suspension then being sterilized. Suitable additives include, for example, physiologically biocompatible buffers (as for example, tromethamine hydrochloride), additions (e.g. 0.01 to 10 mole percent) of chelants (such as, for example, DTPA, DTPA-bisamide or non-complexed chelants of formula I) or calcium chelate complexes (as for example calcium DTPA, CaNaDTPA-bisamide, calcium salts or chelates of chelants of formula VII), or, optionally, additions (e.g. 1 to 50 mole percent) of calcium or sodium salts (for example, calcium chloride, calcium ascorbate, calcium gluconate or calcium lactate combined with metal chelate complexes of chelants of formula I and the like). If the compounds are to be formulated in suspension form, e.g., in water or physiological saline for oral administration, a small amount of soluble chelate may be mixed with one or more of the inactive ingredients traditionally present in oral solutions and/or surfactants and/or aromatics for flavouring. For MRI and for X-ray imaging of some portions of the body the most preferred mode for administering metal chelates as contrast agents is parenteral, e.g. intravenous administration. Parenterally administrable forms, e.g. intravenous solutions, should be sterile and free from physiologically unacceptable agents, and should have low osmolality to minimize irritation or other adverse effects upon administration, and thus the contrast medium should preferably be isotonic or slightly hypertonic. Suitable vehicles include aqueous vehicles customarily used for administering parenteral solutions such as Sodium Chloride Injection, Ringer's Injection, Dextrose Injection, Dextrose and Sodium Chloride Injection, Lactated Ringer's Injection and other solutions such as are described in Remington's Pharmaceutical Sciences, 15th ed., Easton: Mack Publishing Co., pp. 1405-1412 and 1461-1487 (1975) and The National Formulary XIV, 14th ed. Washington: American Pharmaceutical Association (1975). The solutions can contain preservatives, antimicrobial agents, buffers and antioxidants conventionally used for parenteral solutions, excipients and other additives which are compatible with the chelates and which will not interfere with the manufacture, storage or use of products. Where the diagnostic or therapeutic agent comprises a chelate or salt of a toxic metal species, e.g. a heavy metal ion, it may be desirable to include within the formulation a slight excess of the chelating agent, e.g. as discussed by Schering in DE-A-3640708 (U.S. Pat. No. 5,098,692), or more preferably a slight excess of the calcium salt of such a chelating agent. For MR-diagnostic examination, the diagnostic agent of the present invention, if in solution, suspension or dispersion form, will generally contain the metal chelate at concentration in the range 1 micromole to 1.5 mole per liter, preferably 0.1 to 700 mM. The diagnostic agent may however be supplied in a more concentrated form for dilution prior to administration. The diagnostic agent of the invention may conveniently be administered in amounts of from 10 -3 to 3 mmol of the metal species per kilogram of body weight, e.g. about 1 mmol lanthanide (e.g. Dy or Gd)/kg bodyweight. For X-ray examination, the dose of the contrast agent should generally be higher and for scintigraphic examination the dose should generally be lower than for MR examination. For radiotherapy and detoxification, conventional dosages may be used. The disclosures of all of the documents mentioned herein are incorporated by reference. The present invention will now be illustrated further by the following non-limiting Examples. All ratios and percentages given herein are by weight and all temperatures are in degrees Celsius unless otherwise indicated. EXAMPLE 1 Synthesis of N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclo-dodecan-1-methylcarbonyl]-piperazine and the Gadolinium Complex Thereof (a) 1,4,7,10-Tetraazacyclododecane (cyclen) To a suspension of tetraaza-12-crown-4 tetrahydrochloride (66.6 g, 0.209 mol, Parish, Inc.) in chloroform (2 L), was bubbled NH 3 (g) through a gas dispersion tube for 1 hour. The solution was allowed to stir overnight and the white solid was filtered off and washed with CHCl 3 (4×100 mL). The combined filtrate was concentrated in vacuo to a white solid which was washed with diethyl ether (4×50 mL) and dried under vacuum at ambient temperature. A second crop of the free base was isolated from the ether washes to give a combined yield of 35.1 g (97.5%). 1 H NMR (CDCl 3 ): δ 2.32 (s, 4 H), 2.70 (s, 16 H). (b) 1,4,7-Tris-(tert-butoxy-carbonylmethyl)-1,4,7,10-tetraazacyclododecane-hydrobromide Cyclen (35.0 g, 0.203 mole) (Example 1(a)) was dissolved in N,N-dimethylacetamide (DMA, 600 mL) under nitrogen. Sodium acetate (50.0 g, 0.61 mol) was added at once and the mixture was allowed to stir for 0.5 hour. A solution of t-butylbromoacetate (118.9 g, 0.61 mol) in DMA (150 mL) was added dropwise from an addition funnel over a 7 hour period. The reaction mixture was allowed to stir for 19 days at ambient temperature under nitrogen during which time a white solid precipitated from solution. The white solid was then filtered off, washed with chilled DMA (75 mL) and ethyl acetate (100 mL), and dried under vacuum at 50° C. The filtrate was concentrated to approximately 500 mL and a second crop of white solid was collected in a similar manner. The combined solids (80.2 g+38.4 g). were taken up in CHCl 3 (600 mL) and washed with deionized H 2 O (4×100 mL). The organic layer was dried (Na 2 S 4 ), filtered, and concentrated to a light yellow oil. A white solid was obtained by addition of ethyl acetate to the oil. The solid was collected by filtration, washed with diethyl ether (2×75 mL), and dried under vacuum at 45° C. to give 67.4 g (55.7%) of the title monohydrobromide salt. Additional product can be recovered from the filtrates if desired. 1 H NMR (CDCl 3 ): δ 1.42 (s, 27 H), 1.71 (s, 2 H), 2.86 (m, 12 H), 3.06 (br s, 4 H), 3.25 (s, 2 H), 3.34 (s, 4 H). Anal. Calcd (found) for C 26 H 51 N 4 O 6 Br: C, 52.43 (52.47); H, 8.63 (8.48); N, 9.40 (9.50); Br, 13.42 (12.92). (c) Piperazine bis(bromoacetamide) To a 1 L three-necked flask equipped with a magnetic stir bar, reflux condenser and addition funnel, was added bromo acetyl bromide (82.8 g, 0.41 mole) in CHCl 3 (170 mL). The addition funnel was charged with a solution of piperazine (0.2 mole, 17.2 g) and triethylamine (70 mL) in CHCl 3 (180 mL). The flask was chilled to -15° C. by means of a CH 3 CN/liquid N 2 bath, and the amine was slowly added to the acid bromide. After the addition was complete the mixture was allowed to warm to ambient temperature and was stirred for 1 hour. The flask was then cooled to 0° C. and H 2 O (100 mL) was slowly added. The mixture was diluted with CHCl 3 (500 mL) and the layers were separated. The organic layer was extracted with H 2 O (5×50 mL), 0.05N NaOH (5×50 mL) and H 2 O (200 mL), and dried (Na 2 SO 4 ). The dark orange solution was filtered and concentrated to a beige solid. The material was purified by filtration through a bed of silica gel. The product eluted with 2-5% methanol/CH 2 Cl 2 . After combining and concentrating the desired fractions, 15.0 g (49.2%) of a white solid was obtained. The title product was recrystallized from warm 2-propanol (400 mL) affording 9.95 g. 1 H NMR (CDCl 3 ): δ 3.61 (dt, 6 H), 3.85 (s, 4 H). (d) N,N'-Bis[1,4,7-tris-(tert-butoxycarbonyl-methyl)-1,4,7,10-tetraazacyclododecane-10-yl-methyl-carbonyl]-piperazine To a solution of the hydrobromide salt of Example 1(b) (10.0 g, 16.8 mmol) in CHCl 3 (20 mL) and THF (80 mL) was added 1,1,3,3-tetramethylguanidine (TMG, 1.93 g 16.8 mmol). A white solid was produced which was filtered off, washed with 20% CHCl 3 /THF (100 mL) and identified as TMG·HBr. The filtrate was concentrated to a clear oil which was dissolved in N,N-dimethylformamide (DMF, 200 mL) and treated with the bisbromoacetamide of Example 1(c) (2.62 g, 8.0 mmol) and TMG (1.93 g). The light yellow solution was warmed to 60° C. and was allowed to stir for 16 hours under nitrogen. The reaction mixture was cooled to ambient temperature and the DMF was removed under vacuum. The residue was taken up in CH 2 Cl 2 (300 mL) and was washed with 1M Na 2 CO 3 (3×60 mL). The combined aqueous layer was back-extracted with CH 2 Cl 2 (50 mL). The combined CH 2 Cl 2 layers were extracted with 1M HCl (2×80 mL) followed by deionized H 2 O (2×50 mL). The combined HCl and H 2 O layers were washed with CH 2 Cl 2 (50 mL). The aqueous layer was combined with CH 2 Cl 2 (250 mL) in an Erlenmeyer flask, and the pH was adjusted to 9-10 with anhydrous Na 2 CO 3 . The neutralized mixture was transferred to a separating funnel and the layers were separated. The aqueous layer was extracted with CH 2 Cl 2 (2×100 mL), and all of the basic CH 2 Cl 2 layers were combined and washed with H 2 O (2×70 mL). The organic layer was dried (Na 2 SO 4 ), filtered, and concentrated to give 12.3 g of an off-white solid. The solid was triturated with ethyl acetate (50 mL) collected by filtration, washed with ethyl acetate (2×20 mL), diethyl ether (30 mL), and dried under vacuum to give 8.40 g (76%) of a white solid. This material analyzed as the title dimer containing two NaX molecules (where X=Cl or Br). 1 H NMR (CD 3 OD): δ 1.39 (s, 54 H), 1.9-3.5 (br m, 56 H). 13 C NMR (CD 3 OD): δ 174.5, 174.4, 172.2, 82.8, 82.6, 79.5, 56.7, 56.3, 54.0 (br), 49.0 (br), 45.2, 44.9, 42.9, 42.6, 28.5, 28.4. MS (FAB): m/e 1218 (MNa + ). Anal: Calculated (found) for C 60 H 110 N 10 O 14 Na 2 Cl 2 ·4H 2 O: C, 52.04 (52.14); H, 8.59 (8.68); N, 10.12 (10.07); Na, 3.32 (3.44); Cl, 5.12 (5.16). (e) N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecane-10-yl-methylcarbonyl-piperazine A solution of the dimer of Example 1(d) (10.0 g, 7.2 mol) in CH 2 Cl 2 (120 mL) and trifluoroacetic acid (TFA, 80 mL) was allowed to stir at ambient temperature for 1 hour. The volatiles were removed by rotary evaporation to give a thick brown oil. The residue was redissolved in CH 2 Cl 2 and trifluoroacetic acid as above for 1 hour. The process had to be repeated seven times to completely remove all of the t-butyl groups. After the final treatment with TFA, the crude product was concentrated, dissolved in H 2 O (100 mL) and reconcentrated by rotary evaporation. The H 2 O chase was repeated several times. The product was precipitated as a white solid by dissolving the crude mixture in H 2 O (20 mL), warming the solution to 50° C. and adding 2-propanol (150 mL) slowly. The solid was collected by filtration and washed with 2-propanol (2×50 mL) and acetone (2×30 mL). A second crop of product was collected from the filtrate and isolated in a similar fashion. The combined solids were dried under vacuum to give 7.48 g of material that contained traces of sodium and TFA. A portion of the solid, (5.24 g) was dissolved in H 2 O (10 mL) and the pH was adjusted to 10.9 with 2N NaOH. The solution was loaded onto a column containing Bio-Rad AG1-X8 (acetate form) and the column was washed with H 2 O (2 L). The product was then eluted with 0.1N acetic acid. After combining desired fractions and concentrating, the product was precipitated by dissolving in H 2 O (50°-60° C.) and slowly adding 2:1 acetone/ethanol (60 mL). The solid was collected, washed with 2:1 acetone/ethanol (60 mL), and dried in vacuo to give 3.31 g (50%) of the title product. 1 H NMR (NaOD, D 2 O): δ 2.20 (br s, 16 H), 2.46 (br s, 16 H), 2.88 (s, 12 H), 3.26 (d, 4 H), 3.40 (s, 8 H). 13 C NMR (NaOD, D 2 O): δ 180.7, 180.6, 172.4, 59.3, 59.2, 54.9, 54.6, 51.2 (br), 44.6, 44.5, 41.9, 41.8. MS (FAB): m/e 859.5 (MH + ). Anal: Calculated (found) for C 36 H 62 N 10 O 14 ·4.5H 2 O: C, 46.00 (46.00); H, 7.61 (7.45); N, 14.90 (15.01). (f) Bisgadolinium complex of N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecane-10-yl-methylcarbonyl]-piperazine (To a suspension of the dimeric chelant of Example 1(e) (5.65 g, 6.0 mmol) in deionized H 2 O (120 mL) was added gadolinium acetate (4.73 g). A clear slightly yellow solution formed within minutes. The mixture was stirred at ambient temperature for 3 hours and was then concentrated by rotary evaporation (50° C.) to drive off acetic acid. The residue was redissolved in H 2 O (150 mL) and the solution was warmed to 40° C. No gadolinium was detected after 2 hours by a xylenol orange test. Gadolinium acetate was added in 12.2 mg (0.5 mol %) increments until a positive test for free gadolinium was observed. The solution was then treated with ligand to adjust the titer to ≦0.1 mol % excess ligand. The complex was precipitated by dissolving in H 2 O (40° C.) and adding a 2:1 acetone/ethanol solution. The solid was collected by filtration, washed with 2:1 acetone/ethanol (2×25 mL) and dried under vacuum at 35° C. to give 6.4 g (80%) of the title product. MS (FAB): m/e 1168 (M + ). Anal: Calculated (found) for C 36 H 56 N 10 O 14 Gd 2 ·8.75H 2 O: C, 32.64 (32.48); H, 5.58 (5.16); N, 10.57 (10.42); Gd, 23.73 (23.31). EXAMPLE 2 Synthesis of N,N'-bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecane-10-yl-methylcarbonyl]-N,N'-dimethylethylenediamine and the Gadolinium Complex Thereof (a) N,N'-Dimethylethylenediamine bis(bromoacetamide) To a 1 L three-necked flask equipped with a magnetic stir bar, reflux condenser and addition funnel, was added bromoacetyl bromide (46.95 g, 232.6 mole) and CHCl 3 (100 mL). The addition funnel was charged with a solution of N,N'-dimethylethylenediamine (10.0 g, 113.4 mmol) and triethylamine (39.5 mL) in CHCl 3 (100 mL). The flask was chilled to -15° C. by means of an ethylene glycol/CO 2 bath, and the amine was slowly added to the acid bromide. After the addition was complete, the mixture was allowed to warm to ambient temperature and stirred for 1 hour. The flask was then cooled to 0° C. and H 2 O (50 mL) was slowly added. The mixture was diluted with CHCl 3 (250 mL) and the layers were separated. The organic layer was extracted with H 2 O (3×50 mL), 0.05N NaOH (3×50 mL), and H 2 O (2×50 mL), and was dried (Na 2 SO 4 ). The solution was filtered and concentrated. The material was methanol purified by filtration through a bed of silica gel. The product eluted with 2-5% methanol/CH 2 Cl 2 . After combining and concentrating the desired fractions, 14.95 g (39.9%) of a beige solid was obtained. The title product was recrystallized from warm 2-propanol affording 11.94 g. 1 H NMR (CDCl 3 ): δ [2.99 (s), 3.11 (s), 3.13 (S); 6 H], [3.53 (S), 3.57 (S); 4 H], 3.81 (s), 3.84 (s), 3.91 (s); 4 H]. (b) N,N'-Bis[1,4,7-tris-(tert-butoxycarbonylmethyl)1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-N,N'-dimethylethylenediamine To a solution of the hydrobromide salt of Example 1(b) (8.0 g, 13.4 mmol) in CHCl 3 (20 mL) and THF (80 mL) was added 1,1,3,3-tetramethylguanidine (TMG, 1.547 g, 13.4 mmol)). A white solid was produced which was filtered off, washed with 20% CHCl 3 /THF (100 mL) and identified as TMG·HBr. The filtrate was concentrated to a clear oil which was dissolved in N,N-dimethylformamide (DMF, 200 mL) and treated with the his (bromoacetamide) of Example 2(a) (2.21 g, 6.7 mmol) and TMG (1.547 g). The light yellow solution was warmed to 60° C. and was allowed to stir for 16 hours under nitrogen. The reaction mixture was cooled to ambient temperature and the DMF was removed under vacuum. The residue was taken up in CHCl 3 (200 mL) and washed with 1M Na 2 CO 3 (3×40 mL). The combined aqueous layer was back-extracted with CHCl 3 (50 mL). The combined CHCl 3 layers were extracted with 0.8M HCl (2×50 mL) followed by deionized H 2 O (2×50 mL). The combined HCl and H 2 O layers were washed with CHCl 3 (50 mL). The aqueous layer was combined with CHCl 3 (200 mL) in an Erlenmeyer flask, and the pH was adjusted to between 9.5 with Na 2 CO 3 . The neutralized mixture was transferred to a separating funnel and the layers were separated. The aqueous layer was extracted with CHCl 3 (2×100 mL), and the basic CHCl 3 layers were combined and washed with H 2 O (2×50 mL). The organic layer was dried over anhydrous Na 2 SO 4 , filtered and concentrated to give 7.50 g (93%) of the title product as a yellow oil. 1 H NMR (CDCl 3 ): δ 1.24 (s, 54 H), 1.90-3.39 (br m, 67 H). 13 C NMR (CDCl 3 ): δ 27.7, 27.8, 34.9, 45.7, 48.3 (br), 52.0 (br), 55.4, 55.6, 56.3, 81.4, 81.6, 81.6, 81.7, 81.8, 171.5, 172.6, 172.7. (c) N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10 tetraazacyclododecan-10-yl-methylcarbonyl]-N,N-dimethyl-ethlenediamine A solution of the dimer of Example 2(b) (7.50 g) in CH 2 Cl 2 (100 mL) and trifluoroacetic acid (TFA, 60 mL) was allowed to stir at ambient temperature for 1 hour. The volatiles were removed by rotary evaporation to give a thick brown oil. The residue was redissolved in CH 2 Cl 2 (20 mL) and trifluoroacetic acid (15 mL) as above for 1 hour. The process was repeated seven times to completely remove all of the t-butyl groups. After the final treatment with TFA, the crude product was concentrated, dissolved in H 2 O (100 mL) and reconcentrated by rotary evaporation. The H 2 O chase was repeated several times. The product was purified by ion-exchange chromatography (Bio Rad AG1-X8, acetate form) using 0.1N acetic acid to sluts the product. Desired fractions were combined and concentrated to give 2.36 g (37%) of the title product as an off white solid after lyophilization. 1 H NMR (NaOD, D 2 O): δ 2.0-3.7 (br, m). 13 C NMR (NaOD, D 2 O): δ 34.5, 35.4 (br), 43.7, 45.6, 47.2, 47.2, 48.9, 49.6, 50.0, 51.6 (br), 52.5, 55.1, 56.0, 57.3, 59.1, 63.3, 173.4 (br), 179.2, 180.5, 181.4. MS (FAB): m/e 861 (MH + ), 883 (MNa + ), 917 (M+NaCl-H) + ], 973 [(M+2NaCl-2H) + ]. (d) Bisgadolinium complex of N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-N,N-dimethyl-ethylenediamine To a solution of the dimeric chelant of Example 2(c) (1.88 g, 2.0 mmol) in deionized H 2 O (40 mL) was added gadolinium acetate (1.53 g). The light yellow solution was stirred at 40° C. for 1 hour and was then concentrated by rotary evaporation (50° C.) to drive off acetic acid. The residue was redissolved in H 2 O (100 mL) and the solution was warmed to 40° C. The reaction was allowed to stir overnight at ambient temperature. Gadolinium acetate was added in 0.01 mmol increments until a positive test for free gadolinium was observed. The solution was then treated with ligand to adjust the titer to 0.1 mol % excess ligand. The solution was concentrated to dryness and was triturated with 2:1 diethylether/CHCl 3 to give the title product as a beige solid (2.57 g, 98%). EXAMPLE 3 Synthesis of N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]tetrahydroquinoxaline and the Gadolinium Complex Thereof (a) Tetrahydroquinoxaline bis(chloroacetamide) To a 1 L three-necked round bottomed flask equipped with a magnetic stir bar, reflux condenser and addition funnel, was added chloroacetyl chloride (9.6 mL, 0.120 mol) and CHCl 3 (100 mL). The addition funnel was charged with a solution of tetrahydroquinoxaline (8.0 g, 0.0596 mol) and triethylamine (20.8 mL) in CHCl 3 (100 mL). The flask was chilled to 0° C., and the amine was slowly added to the acid chloride. After the addition was complete, the mixture was allowed to warm to ambient temperature and stir for 1 hour. The flask was then cooled to 0° C. and H 2 O (50 mL) was slowly added. The mixture was diluted with CHCl 3 (250 mL) and the layers were separated. The organic layer was washed with H 2 O (50 mL), 0.05N NaOH (2×50 mL), H 2 O (50 mL), 1N HCl (3×50 mL) and H 2 O (2×50 mL), and was dried over anhydrous Na 2 SO 4 . The solution was filtered and concentrated to a brown solid. The solid was collected by filtration, washed with 2-propanol (2×30 mL) and diethylether (2×40 mL) and dried to yield the title product (4.41 g, 51.5%). 1 H NMR (DMSO-d6): δ 3.89 (s, 4 H), 4.01 (s, 4 H), 7.25 (s, 2 H), 7.65 (br s, 2 H). (b) N,N'-Bis[1,4,7-tris-(tert-butoxycarbonyl-methyl)-1,4,7,10-tetraazacyclododecan-10-yl-methyl-carbonyl]tetrahydroquinoxaline To a solution of the hydrobromide salt of Example 1(b) (8.0 g, 13.4 mmol) in CHCl 3 (20 mL) and TMF (80 mL) was added 1,1,3,3-tetramethylguanidine (TMG, 1.547 g, 13.4 mmol)). A white solid was produced which was filtered off, washed with 20% CHCl 3 /THF (100 mL) and identified as TMG·HBr. The filtrate was concentrated to a clear oil which was dissolved in N,N-dimethylformamide (DMF, 250 mL) and treated with bis(chloroacetamide) of Example 3(a) (1.928 g, 6.72 mmol) and TMG (1.547 g). The light yellow solution was warmed to 60° C. and was allowed to stir for approximately 16 hours under nitrogen. The reaction mixture was cooled to ambient temperature and the DMF was removed under vacuum. The residue was taken up in CHCl 3 (200 mL) and was washed with 1M Na 2 C 3 (3×40 mL). The combined aqueous layer was back-extracted with CHCl 3 (50 mL). The combined CHCl 3 layers were extracted with 1M HCl (2×50 mL) followed by deionized H 2 O (2×50 mL). The combined HCl and H 2 O layers were washed with CHCl 3 (2×50 mL). The aqueous layer was combined with CHCl 3 (250 mL) in an Erlenmeyer flask, and the pH was adjusted to 9.5 (Na 2 CO 4 ). The neutralized mixture was transferred to a separating funnel and the layers were separated. The aqueous layer was extracted with CHCl 3 (2×50 mL), and all CHCl 3 layers were combined and washed with brine (2×40 mL). The organic layer was dried (Na 2 SO 4 ), filtered, and concentrated to give 10.60 g of a yellow oil. The title product was purified further by passing through a bed of silica gel and eluting the product with 10% methanol/CHCl 3 to give 7.06 g (84.6%). 1 H NMR (CDCl 3 ): δ 1.30 (s), 1.38 (s), 1.41 (s), 2.0-3.7 (br m), 7.28 (s). (c) N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]tetra-hyquinoxaline A solution of the dimer of Example 3(b) (7.06 g) in CH 2 Cl 2 (70 mL) and trifluoroacetic acid (TFA, 60 mL) was allowed to stir-at ambient temperature for 1 hour. The volatiles were removed by rotary evaporation to give a thick brown oil. The residue was redissolved in CH 2 Cl 2 (70 mL) and trifluoroacetic acid (60 mL) as above for 1 hour. The process was repeated nine times to completely remove all of the t-butyl groups. After the final treatment with TFA, the crude product was concentrated, dissolved in H 2 O (100 mL), and reconcentrated by rotary evaporation. The H 2 O chase was repeated several times. The product was purified by .ion-exchange chromatography column (Bio Rad AG1-X8, acetate form) using 0.1N acetic acid to elute the product. Desired fractions were combined and concentrated to give 3.26 g of an off white solid after lyophilization The solid was triturated with ethanol (50 mL), collected by filtration, washed with diethyl ether and dried to yield the title product (3.18 g, 48%). 1 H NMR (NaOD, D 2 O): δ [2.88 (br s), 3.19 (br s), 3.43 (s), 3.53-3.68 (m); 56 H], 7.07 (m, 3 H), 7.59 (br s, 1 H). (d) Bisgadolinium complex of N,N'-bis[1,4,7-tris (carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-tetrahyquinoxaline To a solution of the dimeric chelant of Example 3(c) (2.50 g, 2.53 mmol) in 100 mL deionized H 2 O (100 mL) was added gadolinium acetate (1.9827 g, 96% of theroretical). The clear solution was stirred at 40° C. for 1 hour and was then concentrated by rotary evaporation (50° C.) to drive off acetic acid. The residue was redissolved in H 2 O (100 mL) and the solution was warmed to 40° C. and the reaction allowed to stir overnight at ambient temperature. Gadolinium acetate was added in 0.5 mol % increments until a positive test for gadolinium was observed. The solution was then treated with ligand to adjust the titer to 0.5 mol % excess ligand. The solution was lyophlized to give 3.28 g of the title product as an off-white solid. Mass spectrum (FAB): m/e 1217 (MH + ). EXAMPLE 4 Synthesis of N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]ethylenediamine and the Gadolinium Complex Thereof (a) Ethylenediamine bis(chloroacetamide) To a solution of ethylenediamine (3.0 g, 0.05 mol) in CHCl 3 (50 mL) cooled to -15° C. was added chloroacetyl chloride (7.96 mL, 0.10 mol) in CHCl 3 (40 mL) dropwise. A white precipitate formed and the reaction mixture was stirred overnight at ambient temperature. After 16 hours the reaction mixture was filtered and the white solid was washed with CHCl 3 (30 mL) followed by water (100 mL). The CHCl 3 layer was washed with water (2×25 mL), dried (Na 2 SO 4 ), and filtered. After being dried under vacuum, the white solid was recrystallized from ethanol and filtered hot to give a clear filtrate from which the product crystallized upon standing. The solid was collected by filtration and washed with isopropyl alcohol (20 mL). The mother liquor from the recrystallization and the CHCl 3 layer were combined and concentrated yielding a white solid which was recrystallized from ethanol and then washed with isopropyl alcohol. The title product (4.9 g, 46%) was obtained as a white solid. 1 HNMR (CDCl 3 ) δ 7.05 (br, 2 H), 4.04 (s, 4 H), 3.49 (s, 4 H). 13 C NMR (DMSO-d 6 ) δ 166.2, 42.7, 38.5. (b) N,N'-Bis[1,4,7-tris-[tert-butoxycarbonyl-methyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl-ethylenediamine The hydrobromide salt of Example 1(b) (4.7 g, 7.9 mmol) was dissolved in 20% CHCl 3 /THF (50 mL). To this solution was added TMG (0.99 mL, 7.9 mmol) with the solution quickly becoming cloudy as TMG.sup.· HBr precipitated. After stirring for 15 minutes, the solution was filtered and the filtrate concentrated to a yellow oil. The oil was taken up in THF (80 mL) and transferred to a three necked round bottom flask. The flask was then charged with NaI (590 mg, 3.9 mmol), TMG (0.99 mL, 7.9 mmol), and finally the bischloroacetamide of Example 4(a) (837 mg, 3.93 mmol). The reaction mixture was placed under N 2 and heated to 68° C. After 16 hours, the reaction mixture was filtered and the filtrate concentrated to a gummy solid. The residue was taken up in CH 2 Cl 2 and washed with 1.0N Na 2 CO 3 (3×50 mL). The aqueous phase was back extracted with CH 2 Cl 2 . The organic portions were combined and extracted with 1M HCl (1×80 mL). The aqueous phase was then washed with CH 2 Cl 2 and the pH of the aqueous phase was adjusted to 9 with Na 2 CO 3 . The aqueous layer was then extracted with CH 2 Cl 2 (1×200 mL, 2×100 mL) and the CH 2 Cl 2 layer washed with water (2×75 mL), dried (MgSO 4 ), and filtered. Concentration and drying under vacuum yielded 3.6 grams (79%) of the title compound as a pale yellow solid. 1 H NMR (CDCl 3 ) δ 3.34-2.00 (br band, 57 H), 1.44 (br s, 54 H). (c) N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-ethylene-diamine The ethylenediamine dimer of Example 4(b) (6.7 g; 5.7 mmol) was dissolved in CH 2 Cl 2 (40 mL) and a 1:1 solution of TFA/CH 2 Cl 2 (20 mL) was added. The resulting mixture was stirred for one hour and then concentrated. This procedure was repeated eight times to complete the deprotection. After the final deprotection, the solution was concentrated and chased with water (3×25 mL) to yield a 6.2 grams of a brownish solid. The solid was dissolved in water (15 mL), the pH was adjusted to 10.9 with 3N LiOH, and the solution was loaded onto AG1-X8 ion exchange resin. (acetate form). The column bed was washed with water (1 L), and the dimer eluted from the column with 0.1N acetic acid with the desired fractions being combined and concentrated yielding 2.5 g (51%) of the the product as a pale yellow solid. 1 H NMR (D 2 O) δ 3.62-2.89 (br band). (d) Bisgadolinium complex of N,N'-bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]ethlenediamine The dimeric chelant of Example 4(c) (2.12 g, 2.32 mmol) was dissolved in water (50 mL) and gadolinium acetate (1.81 g, 2.25 mmol) was added. The mixture was allowed to stir at ambient temperature for 1.5 hours, the solution was concentrated, and the residue was taken up in water (50 mL). After another 1.5 hours, the solution gave a positive xylenol orange test, therefore the solution was concentrated and chased with water (1×20 mL). The residue was taken up in water (50 mL) and allowed to stir overnight at ambient temperature. After stirring for 16 hours, the solution was chased with water to remove the acetic acid formed. Additional ligand was added in 21 mg (0.07 mmol) portions until the xylenol orange test gave a positive (purple) color. A final portion of 21 mg of ligand was added and the solution was stirred for two hours at 40° C. A xylenol orange test was performed and gave a negative result. The solution was then concentrated to give a pale yellow solid. The solid was dissolved in warm water (15 mL) to which was added a 2:1 acetone/ethanol solution (85 mL) from which a white solid precipitated. The solid was collected by filtration and washed with 2:1 acetone/ethanol solution (200 mL) followed by acetone (30 mL) and dried in a vacuum oven (35° C.) for 3.5 hours to yield 2.4 g of the title product as a white solid. MS (FAB): m/e 1143.2 (MH + ). Anal: Calculated for C 34 H 54 Gd 2 N 10 O 14 ·3.4H 2 O: C,29.53; H,5.89; Gd,22.74;N,10.13. Found C,29.47; H,5.59; Gd,22.54;N,9.81. EXAMPLE 5 Synthesis of N,N'-bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]homopiperazine and the Gadolinium Complex Thereof (a) Homopiperazine bis(chloroacetamide) Homopiperazine (10 g; 100 mmol) was dissolved in chloroform (150 mL) and triethylamine (28 mL; 500 mmol) was added to the mixture. The solution was cooled to -30° C. under nitrogen and chloroacetyl chloride (17 mL, 213 mmol) was added over a period of 1 hour. The solution was stirred at -30° C. for 1 hour, at 0° C. for 2 hour and at ambient temperature overnight. The solution was washed with water (4×50 mL), dried over anhydrous MgSO 4 , filtered and concentrated. The oily residue was purified by column chromatography on silica gel (5% methanol in chloroform) to yield the title product as an oil which solidified on prolonged standing (10.3 g; 41%). 1 H NMR (CDCl 3 ): 4.04 (m, 4 H), 3.62 (m, 8 H), and 1.94 (m, 2H). (b) N,N'-Bis[1,4,7-tris-[tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]homopiperazine A solution of the bis(chloroacetamide) of Example 5(a) (1.7 g, 6.72 mmol), DO3A-tri-t-butyl ester (8 g, 13.43 mmol) and tetramethylguanidine (2.6 mL, 20.75 mmol) in acetonitrile (300 mL) was heated at 60° C. for 25 hours under nitrogen. The solvent was removed under reduced pressure and the residue redissolved in chloroform (60 mL). The solution was washed with 1M sodium carbonate (2×50 mL) and water (2×50 mL) and extracted with 1M HCl (4×50 mL) followed by water (2×50 mL). The aqueous extracts were combined and basified with solid sodium carbonate. The crude product that separated as an oil was extracted with chloroform (3×100 mL), dried over anhydrous magnesium sulfate, filtered, and concentrated to yield the crude title product as a yellow solid (9.77 g). 1 H NMR (CDCl 3 ): 3.44-2.45 (m, 56 H), 1.84 (s, 2 H), 1.42 (s, 18 H), 1.40 (s, 36 H). (c) N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]homopiperazine A solution of the crude t-butyl ester of Example 5(b) (9.77 g) in CH 2 Cl 2 (30 mL) was treated with trifluoroacetic acid (30 mL) and the mixture stirred at ambient temperature for 1 hour. The solution was concentrated and the process repeated seven times. The oily residue (10.5 g) obtained after the final deprotection was dissolved in acetone (30 mL) and was precipitated with chloroform. Filtration and drying under vacuum yielded a yellow solid (8.33 g). The solid was dissolved in water (20 mL) and the pH of the solution was adjusted to 11.0 with 3.0N LiOH. The solution was loaded onto an AG1-X8 ion exchange column (acetate form) and the column bed was washed with water. (1 L). The desired dimer was eluted with 0.1N acetic acid with the desired fractions being combined and and concentrated. Lyophilization of the product yielded 3.8 g (54%) of the title product as a yellow solid. 1 H NMR (D 2 O) δ 3.63-2.74 (br band, 56 H), 1.6 (br s, 2 H) (d) Bisgadolinium complex of N,N'-bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]homopiperazine To the dimeric chelant of Example 5(c) (3.11 g, 3.26 mmol) dissolved in water (60 mL) was added gadolinium acetate (2.52 g, 6.30 mmol). The solution was warmed to 40° C. for one hour and then concentrated to remove the acetic acid formed. Water (60 mL) was again added, the solution was stirred for one hour, and the process to remove the acetic acid repeated. The solid was then taken up in water (60 mL) and stirred overnight at ambient temperature. The solution gave a weakly positive xylenol orange test, therefore ligand (31 mg, 0.07 mmol) was added. After 1.5 hours at 40° C. the reaction mixture gave a negative xylenol orange test. The solution was concentrated and then dissolved in ethanol. Acetone was added and the precipitated complex collected by filtration. The solid was taken up in acetone and stirred for 1 hour and then collected by filtration. The solid was dried in a vacuum oven (35° C.) for two hours to give 3.2 g (76%) of the title product as a fine white powder. MS (FAB): m/e 1183.3 (MH + ). Anal: Calculated for C 37 H 58 Gd 2 N 10 O 14 ·12.3 H 2 O.sup.· 0.72 acetone: C,32.55; H, 6.06; Gd,21.77; N,9.69. Found C,32.92; H,5.69; Gd,21.47;N,9.91. EXAMPLE 6 Synthesis of N,N'-bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-2,2'-(ethylenedioxy)diethylamine and the Gadolinium Complex Thereof 2,2'-(Ethylenedioxy)diethylamine bis(chloroacetamide) To a solution of 2,2'(ethylenedioxy)diethylamine (10.0 g, 0.0675 mol) in CH 2 Cl 2 (190 mL) was added Na 2 CO 3 (14.2 g, 0.135 mol). The resulting mixture was chilled in an ice bath and placed under a stream of N 2 to which was added chloroacetyl chloride (10.7 mL, 0.135 mol) in CH 2 Cl 2 dropwise over a period of 25 minutes. Upon completion of addition, the ice bath was removed and the mixture was stirred at ambient temperature for two hours. The reaction mixture was then filtered and the filtrate was washed with water (150 mL), saturated NaHCO 3 (150 mL), and finally water (150 mL). The organic phase was dried (over Mg 2 SO 4 ), filtered, and concentrated to yield a yellow oil which solidified when placed under vacuum. The solid was triturated with a 1:1 mixture of ethyl acetate/hexane (150 mL). A white solid was collected by filtration and dried in a vacuum oven (50° C.) for 6 hours yielding 6.9 g (34%) of the title product. 1 H NMR (CDCl 3 ) δ 6.97 (br s, 2 H), 4.03 (s, 4 H), 3.60 (s, 4 H), 3.56 (distorted t, 4 H), 3.50 (t, 4 H); 13 C NMR (CDCl) δ 165.9, 70.1, 69.1 42.4, 39.3. (b) N,N'-Bis[1,4,7-tris-(tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-2,2'-(ethylenedioxy)diethylamine The hydrobromide salt of Example 1(b) (19.8 g, 33.2 mmol) was dissolved in 20% CHCl 3 /THF (250 mL). To this solution was added TMG (4.16 mL, 33.2 mmol) and the solution quickly became cloudy as TMG.sup.· HBr precipitated. After stirring for 20 minutes, the solution was filtered with the filtrate being concentrated to a thick yellow oil. The residue was taken up in THF (100 mL) and transferred to a 1 L flask which was then charged with NaI (2.48 g, 16.6 mmol), TMG (4.16 ml, 33.2 mmol), and finally the bis(chloroacetamide) of Example 6(a) (5.0 g, 16.6 mmol). Additional THF (150 mL) was added, the system was placed under a stream of N 2 , and the reaction mixture was heated to 65° C. After four days, the reaction mixture was filtered and the filtrate concentrated to a reddish solid. The solid was taken up in CH 2 Cl 2 (110 mL) and washed with water (3×100 mL). The organic portion was dried (MgSO 4 ), filtered and concentrated to yield 22.14 g (114%) of the title product as a tacky yellow solid which was not analyzed for salts. 1 H NMR (CDCl 3 ) δ 3.39-2.06 (br band, 62 H), 1.25 (br s, 54 H). (c) N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetracyclododecan-10-yl-methylcarbonyl]-2,2'-(ethylenedioxy)diethylamine The crude dimer of Example 6(b) (22.0 g, 18.7 mmol) was dissolved in CH 2 Cl 2 (25 mL). To this solution was added a mixture of TFA (25 mL) and CH 2 Cl 2 (10 mL). After stirring for 2 hours at ambient temperature, the reaction was concentrated. This procedure was repeated seven times to complete the deprotection. After the final deprotection, the solution was concentrated and chased with water (3×40 mL). The reddish semi-solid was then dissolved in water (30 mL) and the pH adjusted to 2.3 with 3.0N NH 4 OH. The solution was loaded onto an AG50-X8 ion-exchange resin (H + form) and the column bed washed with water (1.8 L). The dimer was eluted from the column with 0.5N NH 4 OH with the desired fractions being combined and concentrated to yield 9.8 g (57%) of the title product as a yellow solid. 1 H NMR (D 2 O) δ 3.61-2.92 (br band). MS (FAB): m/e 921.4 (MH + ). (d) Bisgadolinium complex of N,N'-bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-2,2'-(ethylenedioxy)diethylamine To a solution of the DO3A dimer of Example 6(c) (5.90 g, 5.94 mmol) in water (50 mL) was added gadolinium acetate (3.61 g, 8.91 mmol) and the reaction mixture was warmed to 40° C. for 1.5 hours at which time the xylenol orange test was negative. Gadolinium acetate (240 mg, 0.594 mmol) was added in increments until a positive (purple) xylenol orange was achieved. Ligand was then added to achieve a negative xylenol orange test. The solution was reduced in volume and lyophilized yielding 7.58 g of crude complex. The crude complex was purified by HPLC employing a reverse phase C18 column using 2% methanol/water as the mobile phase. MS (FAB): m/e 1231.0 (MH + ) Anal: Calculated for C 38 H 62 Gd 2 N 10 O 16 .sup.· 7.65H 2 O: C,33.38; H,5.70; Gd,23.00;N,10.24. Found C,33.48; H,5.79; Gd,22.75; N,10.50. EXAMPLE 7 Synthesis of N,N'-bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-N,N'-bis(2,3-dihydroxypropyl)-ethylenediamine and the Gadolinium Complex Thereof (a) 1,2,5,6-Di-isopropylidene-D-mannitol To a solution of (411 g, 3.01 mol) of ZnCl 2 in 1.5 L of acetone cooled to 0° C. was added (250 g, 1.37 mol) of D-mannitol and the mixture stirred at ambient temperature for 5 hours. The solid was filtered off and the filtrate poured into a solution of diethyl ether (1.8 L) and potassium carbonate (470 g, 3.4 mol) producing vigorous bubbling. The solution was stirred for 1 hour. A white precipitate was filtered off and the filtrate was dried (K 2 CO 3 ), and concentrated leaving a white solid which was recrystallized from n-butyl ether to give 160 g (50%) of the title product as white needles. 1 H NMR (CDCl 3 ) δ 4.2 (m, 4 H), 4.0 (t, 2 H), 3.7 (d, 2 H), 2.7 (s, 2 H), 1.4 (d, 12 H). (b) Isopropylidene-glyceraldehyde The mannitol derivative of Example 7(a) (81 g, 0.311 mol) was suspended in CH 2 Cl 2 (1.1 L) and saturated NaHCO 3 (40 mL) and stirred at ambient temperature. Sodium periodate (100 g, 0.47 mol) was added in four portions over 20 minutes and the solution was stirred vigorously at 0° C. for 3 hours. The solvent was decanted off and the remaining solid was stirred in CH 2 Cl 2 and then filtered to remove the excess solid. The two organic portions were combined and concentrated in vacuo. The resulting oil was distilled at reduced pressure to give the title product as a clear, viscous oil. Yield (59 g, 75%). 1 H NMR (CDCl 3 ) δ 4.3 (t, 1 H), 3.9 (m, 2 H), 1.4 (d, 6 H). (c) N,N'-Bis(2,3-dihydroxypropyl)ethylenediamine bisacetonide Ethylenediamine (13.2 g, 0.22 mol) was dissolved in methanol (150 mL) and the solution was adjusted with a 1:1 HCl/methanol mixture to pH 7. The solution was cooled with an ice bath and isopropylidene-glyceraldehyde of Example 7(b) (59 g, 0.45 mol) was added followed by portionwise addition of NaCNBH 3 (28.3 g, 0.45 mol). The reaction mixture was stirred at 25° C. under N 2 for 72 hours. The pH of the solution was then lowered to 3 with HCl/methanol and the solvent was stripped off in vacuo. The solid was taken up in H 2 O and extracted with diethyl ether (3×200 mL). The pH of the aqueous phase was raised to 11 and extracted again with diethyl ether (4×200 mL). The ether washes were combined, dried (MgSO 4 ) and concentrated to a yellow oil. The title product was isolated by flash chromatography. (5% methanol/CHCl 3 ). Yield (37 g, 58%). 1 HNMR (CDCl 3 ) δ 4.1 (m, 4 H), 3.3 (m, 2 H), 2.6 (m, 8 H), 1.4 (d,12 H). (d) N,N'-Bis(2,3-dihydroxypropyl)ethylenediamine bisacetonide bischloroacetamide The compound of Example 7(c) (37 g, 0.13 mol) and triethylamine (25.96 g, 0.25 mol) were combined in CH 2 Cl 2 (300 mL). Chloroacetyl chloride (28.9 g, 0.25 mol) was added dropwise at 0° C. under N 2 . A color change was observed along with a white precipitate as the reaction mixture was allowed to return to ambient temperature. After 24 hours, H 2 O (150 mL) was added, the organic layer was separated, washed with water (3×100 mL), dried (MgSO 4 ) and concentrated to a dark viscous oil. The title product (23 g, 41%) was isolated by flash chromatography, 10% methanol/CHCl 3 . MS (FAB): m/e 442 (MH + ). (e) N,N'-Bis[1,4,7-tris-(tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]N,N'-bis(2,3-dihydroxypropyl)-ethylenediamine bisacetonide The hydrobromide salt of Example 1(b) (12 g, 0.02 mol) and the compound of Example 7(d) (4.5 g, 0.01 mol) were dissolved in CH 3 CN (300 mL) and tetramethylguanidine (7.6 mL, 0.61 mol). The reaction mixture was heated to 60° C. and stirred under N 2 for 6 days. The solvent was stripped off and the resulting dark oil taken up in CHCl 3 and extracted with water (3×100 mL), dried (MgSO 4 ) and concentrated to give (12 g, 80%) of the title product MS(FAB): m/e 1398 (MH + ). (f) N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]N,N'-bis(2,3-dihydroxypropyl)ethylenediamine The dimer of Example 7(e) was dissolved in CHCl 3 (175 mL) and trifluoroacetic acid (175 mL) was added dropwise. The reaction mixture was allowed to stir for 1 hour at ambient temperature under N 2 and then concentrated in vacuo to a dark oil. The acid treatment was repeated ten times to remove all t-butyl groups and the acetonides. The solvent was stripped off and the title product purified via preparative HPLC. (Supelco activated C18 reverse-phase column, 3% methanol mobile phase). Yield (9 g, 85%); MS (FAB): m/e 982 (MH + ). (g) Gadolinium complex of N,N'-bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-N,N'-bis(2,3-dihydroypropyl)-ethylenediamine The dimeric chelant of Example 7(E) (10 g, 10.2 mmol) was dissolved in H 2 O (175 mL). Gadolinium triacetate (5.45 g, 0.016 mol, 80% of the theoretical stoichiometric amount) was added and the pH was adjusted to 7 using NH 4 OH. The reaction mixture was stirred at 50° C. for 2 hours. Additional Gadolinium triacetate was added in 5 mol % increments until a xylenol orange test for gadolinium was positive. The reaction was stirred for an additional 24 hours and the xylenol orange test repeated, giving a positive result. Purification of the title product was achieved by preparative HPLC (Supelco activated C18 reverse-phase column, 100% H 2 O mobile phase) to yield (500 mg, 5%) MS (FAB): m/e 1290 (MH + ) Anal. calculated for C 40 D 66 Gd 2 N 10 O 18 w 3 H 2 O: C, 35.76; H, 5.4; Gd, 23.36; N, 10.43; found C, 35.3; H, 5.59; Gd, 23.17; N, 10.9. EXAMPLE 8 Synthesis of N,N'-bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecane-10-yl-methylcarbonyl]-N,N'-bis(2-hydroxyethyl)ethylenediamine and the Gadolinium Complex Thereof (a) bis(BOC)-bis(2-hydroxyethyl) ethylene diamine N,N'-bis(hydroxyethyl)ethylene diamine (2 g; 13.5 mmol) was dissolved in methanol and the solution was treated with di-t-butyl dicarbonate (6.0 g; 27.5 mmol). The solution was stirred at ambient temperature for 9 hours under nitrogen and concentrated. The residue was washed with petroleum ether and dried under vacuum to obtain the title product as a colorless solid (4.48 g; 95.3%). 1 HNMR (CDCl 3 ): δ 1.42 (s, 18H), 3.44-3.35 (m, 8H), 3.44 (s), 3.7 (m, 4H), 4.89 (br s, 2 H). Bis(BOC)-bis(2-benzyloxyethyl)ethylene diamine An 80% mineral oil suspension of sodium hydride (0.75 g; 25 mmol) was washed with tetrahydrofuran under a blanket of nitrogen and re-suspended in tetrahydrofuran (25 mL). Benzyl bromide (20 mL; 169 mmol) and the diamine of Example 8(a) (4.37 g; 12.54 mmol) were added in succession. Following a vigorous initial reaction, the suspension was stirred overnight at ambient temperature under nitrogen. The solution was concentrated under vacuum and the excess benzyl bromide was distilled off under vacuum at 40° C. and the residue containing approximately 10% benzyl bromide was dried under vacuum to yield the title product as a yellow solid (7.18 g, 108%). 1 H NMR (CDCl 3 ): δ 1.39 (s, 9H), 1.42 (s, 9H), 3.38-3.66 (m, 10H), 4.49 (s, 4H), 7.29 (m, 10H). (c) Bis(2-benzyloxyethyl)ethylenediamine The diamine of Example 8(b) (7.18 g) was dissolved in CH 2 Cl 2 (40 mL) and cooled to 0° C. Trifluoroacetic acid (35 mL) was added and the solution was stirred at ambient temperature for 2 hours. After concentration, the title product was washed with petroleum ether and dried under vacuum. Yield: 7.2 g (93%). 1 H NMR (CDCl 3 ): δ 7.27 (m, 10H), 4.46 (s, 4H), 3.65 (t, 4H), 3.44 (s, 4H), 3.11 (t, 4H). (d) Bis(chloroacetyl)-bis(2-benzyloxyethyl)-ethylenediamine A solution of the compound of Example 8(c) (6.81 g; 20.75 mmol) and triethylamine (5.0 mL, 41.5 mmol) in CH 2 Cl 2 (250 mL) was cooled to 0° C. under nitrogen and chloroacetyl chloride (3.3 mL, 41.5 mmol) was added dropwise with stirring. The solution was stirred at ambient temperature for 24 hours and washed with water (7×20 mL), dried (MgSO 4 ), and concentrated. The crude title product was purified by column chromatography on silica gel (ether eluent) to give 2.94 g (29%). 1 H NMR (CDCl 3 ): δ 7.28 (m, 10 H), 4.44 (m, 4 H), 4.21 (d, 4 H), 3.65-3.35 (s); 3.35 (m, 12 H). (e) N,N'-Bis[1,4,7-tris-(tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecan-19-yl-methylcarbonyl)bis(2-benzyloxyethyl)ethylenediamine A solution of the diamine of Example 8(d) (2.94 g, 6.1 mmol), the hydrobromide salt of Example 1(b) (7.27 g, 12.2 mmol), sodium iodide (0.9 g, 6.1 mmol), and tetramethylguanidine (2.3 mL, 18.3 mmol) in acetonitrile (130 mL) was heated at 60° C. under nitrogen for 19 hours. The solvent was removed under vacuum and the residue was redissolved in CH 2 Cl 2 (150 mL), washed with water (100 mL), 1M Na 2 CO 3 (2×100 mL) and water (100 mL). The organic layer was extracted with 1M HCl (4×100 mL) and water (100 mL). The combined aqueous layer was basified with solid Na 2 CO 3 and extracted with CH 2 Cl 2 (4×100 mL). The organic layer was dried (Na 2 SO 4 ) and concentrated. The crude title product (11 g, 62%) was obtained as a brown solid. 1 H NMR (CDCl 3 ): δ 7.28 (m, 10 H), 4.45 (m, 8 H), 3.89-2.58 (m, 60 H), 1.45 (s, 18 H), 1.32 (s, 32 H). (f) N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]bis(benzyloxy-ethyl)ethylene diamine The crude dimer of Example 8(e) (11 g) was dissolved in CH 2 Cl 2 (50 mL) and treated with trifluoroacetic acid (40 mL). The mixture was stirred at ambient temperature for 1 hour and concentrated. This process was repeated seven times. After the final deprotection the product was chased with CH 2 Cl 2 (3×15 mL) and water (3×15 mL) and purified by ion-exchange chromatography on BioRad AG1 X-8 resin (100-200 mesh, acetate form), eluting with 0.1M acetic acid. Further purification was effected by precipitation of the product from methanol by the addition of acetone, when the title product separated as a yellow solid (4.08 g; 47%). 1 H NMR (D 2 O) : δ 7.15 (s, 10 H), 4.30 (m, 4 H), 3.60 (s), 3.60-2.87 (m, 60 H). (g) N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-bis(2-hydroxy-ethyl)ethlenediamine The dimer of Example 8(f) (4.05 g: 3.68 mmol) was dissolved in a mixture of water (25 mL) and glacial acetic acid (15 mL) and treated with Pearlman's catalyst (2 g) and the mixture was hydrogenated in a Parr apparatus at 52 psi until the hydrogen uptake ceased. The solution was then filtered and concentrated. The residue was dissolved in methanol (50 mL) and precipitated with acetone addition (100 mL). This process was repeated again and the title product, a pale yellow solid was dried under vacuum. Yield: 3.07 g (88.6%). 1 H NMR (D 2 O) : δ 3.59-2.93 (m). 13 C NMR (D 2 O): δ 177.05; 171.74; 171.4; 169.87; 169.52; 58.52; 58.35; 56.14; 55.45; 55.28; 55.04; 52.26; 52.36; 50.97; 50.38; 49.81; 48.85; 48.59; 47.84; 44.33; 43.68; 42.97; 38.68; 37.96; 29.85. (h) Bisgadolinium complex of N,N'-bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]bis(2-hydroxyethyl)-ethylenediamine The dimeric chelant of Example 8(g) (3.0 g, 3.26 mmol) was dissolved in water (30 mL) and gadolinium acetate (2.38 g, 5.86 mmol) was added. The solution was stirred at ambient temperature for 2 hours and at 40° C. for 3 hours. It was then concentrated, chased with water and redissolved in water. The solution gave a positive xylenol orange test. Addition of the ligand (in 1 weight % increments) followed by heating at 40° C. for 1 hour was continued until the solution gave a negative xylenol orange test. The solution was then concentrated and chased with water (2×20 mL). Further purification by precipitation from methanol/acetone solvent system (x 6) and passage through BioRad AG1-X8 resin (acetate form) yielded the title product as a yellow solid (3.13 g, 78%). MS (FAB): m/e: 1230 (MH + ). Final purification for toxicity studies was effected by semi-preparative HPLC on a C18 column. Elemental analysis; calculated for C 38 H 62 Gd 2 N 10 O 16 ·13.1 H 2 O: C 31.15%, H 6.07%, Gd 21.46%, N 9.56%; found: C 31.27%, H 5.61%, Gd 21.0% N 9.56%. EXAMPLE 9 Synthesis of N,N'-bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-1-(N-methylglucaminecarbonyl)-ethylenediamine and Bisgadolinium Complex Thereof (a) N-BOC-N-methylqlucamine N-methylglucamine (4.0 g; 20.49 mmol) and di-t-butyl dicarbonate (4.48 g; 20.51 mmol) were dissolved in methanol (40 mL) and the solution was stirred under nitrogen for 24 hours. Concentration and washing with petroleum ether yielded the title product as a colorless solid (6.48 g, 100%). 1 H NMR (D 2 O): δ 3.59-3.38 (m, 6 H), 3.1 (s, 2 H), 2.67 (br, 3 H), 1.21 (s, 9 H). (b) N-BOC-N-methyl-pentakis-(O-benzyl)glucamine An 80% suspension of sodium hydride (1.5 g, 50 mmol) was washed with tetrahydrofuran (20 mL) under nitrogen. Benzyl bromide (17.8 mL, 150 mmol) and tetrahydrofuran (30 mL) were added followed by N-BOC-N-methylglucamine (Example 9(a), 2.95 g, 10 mmol). The mixture was stirred at ambient temperature under nitrogen overnight. The reaction was quenched by the gradual addition of water (30 mL) with stirring. The organic layer was separated and the aqueous layer extracted with CH 2 Cl 2 (2×30 mL). The combined organic extract was washed with water, dried (MgSO 4 ) and concentrated to obtain a yellow oil from which the excess benzyl bromide was distilled off under vacuum at a bath temperature of 100° C. The crude title product was obtained as a sticky yellow solid (7 g; 94%). 1 H NMR (CDCl 3 ): δ 7.38 (m, 25 H), 4.79-4.44 (m, 10 H), 4.04-3.76 (m, 6 H), 3.49 (m, 2 H), 2.96 (s), 2.78 (d, 3 H), 1.48-1.44 (d, 9 H). 13 C NMR (CDCl 3 ): 155.72; 138.53 (m); 127.68 (m); 79.0-76.49 (m); 73.93-69.60 (m); 49.96; 35.94; 28.41. (c) N-methyl-pentakis (O-benzyl)glucamine The crude glucamine of Example 9(b) (7.02 g, 9.43 mmol) was dissolved in CH 2 Cl 2 (25 mL) and the solution was cooled in an ice bath. Trifluoroacetic acid (40 mL) was added and the mixture was stirred at ambient temperature for 2 hours. The solution was concentrated and the deprotection process was repeated again. The solution was chased with CH 2 Cl 2 (2×15 mL), washed with saturated NaHCO 3 (30 mL), water (30 mL), dried (Na 2 SO 4 ), and concentrated to yield the title product as a brown oil which was purified by chromatography on silica gel using 5% methanol in chloroform as the eluent. Yield: 5.55 g (91%). 1 H NMR (CDCl 3 ) : δ 7.33 (m, 25 H), 4.8-4.41 (m, 10 H), 4.06-3.61 (m, 6 H) 3.03-2.71 (m, 2 H), 2.41 (s, 3 H). 13 C NMR (CDCl 3 ): δ 137.97 (m); 128.25; 78.85-69.55 (m); 50.41; 39.94. (d) N,N'-Bis(BOC) -2,3-diaminoproionic acid A suspension of diaminopropionic acid hydrochloride (5.13 g, 36.5 mmol) in a mixture of ethanol (70 mL) and methanol (20 mL) was treated with triethylamine (10.2 mL, 73 mmol), diisopropylethylamine (5 mL),and di-t-butyldicarbonate (16.72 g, 76.6 mmol). The mixture was stirred at ambient temperature overnight and refluxed for 7 hours under nitrogen. The solution was filtered and concentrated. The residue was washed with petroleum ether (3×20 mL), treated with chloroform (150 mL) and the mixture cooled to 0° C. 1M H 2 SO 4 (150 mL) was added and the mixture was stirred at 0° C. for 15 minutes. The aqueous layer was removed and extracted with chloroform (2×30 mL). The combined organic layers were washed with water, dried (Na 2 SO 4 ) and concentrated to obtain the title product as a colorless solid (9.57 g; 86.3%). 1 H NMR (CDCl 3 ): δ 7.34 (br, 1 H), 6.25-5.19 (br, 2 H), 4.3 (br, 1 H), 3.52 (m, 2 H), 1.42 (s, 18 H). 13 C NMR (CDCl 3 ): δ 173.32; 54.69; 42.22; 28.29. (e) N,N'-Bis(BOC)-(N-methyl-pentakis-O-benzyl-glucaminecarbonyl)-ethlenediamine A mixture of the propionic acid of Example 9(d) (2.24 g, 7.37 mmol), dicyclohexylcarbodiiimide (1.52 g, 7.37 mmol), the glucamine of Example 9(c) (4.76 mg, 7.37 mmol) and dimethylaminopyridine (0.09 mg, 0.74 mmol) in CH 2 Cl 2 (50 mL) was stirred at ambient temperature under nitrogen overnight. The solution was filtered, washed with water, dried (MgSO 4 ) and concentrated to give a brown oil. Purification by column chromatography on silica gel (chloroform eluent) yielded the title product (6.19 g; 90%). 1 H NMR (CDCl 3 ): δ 7.32 (m, 25 H), 4.81-4.65 (m, 10 H), 4.04-3.75 (m, 4 H), 1.45 (d, 18 H). 13 C NMR (CDCl 3 ): δ 170.17, 169.92, 155.8, 155.2, 138.21, 127.76, 79.46-76.49 (m), 74.30-69.21 (m), 50.78-48.65 (m), 42.59, 36.31, 28.15, 28.1, 25.46, 24.81. (f) N-methyl-pentakis(O-benzyl)glucamine-carbonylethylenediamine The ethylenediamine of Example 9 (e) (5g) was dissolved in CH 2 Cl 2 (60 mL) and the solution was cooled to 0° C. Trifluoroacetic acid (60 mL) was added and the solution was stirred at ambient temperature for 2 hours. The solution was concentrated and the process was repeated again. After concentration the residue was chased with CH 2 Cl 2 (3×15 mL), dissolved in CHCl 3 , and washed with saturated NaHCO 3 (2×30 mL) and water and dried (MgSO 4 ). The title product was obtained as a brown oil after concentration (4.72 g). 1 H NMR (CDCl 3 ): δ 7.3 (m, 25 H), 4.76-4.25 (m, 11 H), 3.96-3.41 (m, 10 H), 2.94-2.52 (m, 3 H). 13 C NMR (CDCl 3 ): δ 138.62, 127.7, 78.89-76.5 (m), 74.63-69.55 (m), 53.62-46.0 (m), 39.62-24.90. MS (FAB): m/e: 732.6 (MH + ). (g) N-methyl-pentakis(O-benzv)glucaminecarbonyl-ethylenediamine-bis(chloroacetamine) The ethylenediamine of Example 9 (f) (3.9 g, 5.33 mmol) and triethylamine (1.5 mL, 10.7 mmol) were dissolved in chloroform (50 mL) and the solution was cooled to 0° C. under nitrogen. Chloroacetyl chloride (1.2 g, 10.6 mmol) was added slowly. After the addition was complete the solution was warmed to ambient temperature and stirred overnight. The solution was washed with water (3×20 mL), dried (MgSO 4 ) and concentrated. The residue was chromatographed on silica gel, eluting with methanol/chloroform solvent mixture (0-5%) to yield the title product 3.82 g (81%). 1 H NMR (CDCl 3 ): δ 7.30 (m, 25 H), 4.78-4.40 (m, 10 H), 4.30 (m, 1 H), 4.01-3.19 (m, 14 H), 2.94-2.51 (m, 3 H). 13 C NMR (CDCl 3 ): δ 168.85-165.55 (m), 137.98-137.5 (m), 127.86-126.74 (m), 78.29-75.55 (m), 74.09-71.38 (m), 68.94-68.72 (m), 49.08-48.64 (m), 42.14-40.99 (m), 36.5; 35.8, 33.76-33.1, 25.07, 24.41. MS (FAB): m/e 884.4 (MH + ). (h) N,N'-Bis[1,4,7-tris-(tert-butoxycarbonyl-methyl)-1,4,7,10 -tetraazacyclodecan-10-yl-methyl-carbonyl]-N-methyl-pentakis (O-benzyl)glucamine-carbony-ethylenediamine The hydrobromide salt of Example 1(b) (5.12 g, 8.6 mmol) and the bis(chloroacetamide) of Example 9(g) (3.8 g, 4.3 mmol) were dissolved in CH 3 CN (100 mL) and tetramethylguanidine (1.62 mL, 12.9 mmol) was added. The solution was heated at 60° C. under nitrogen for 25 hours. After concentration, the residue was taken up in chloroform and washed with water and dried (MgSO 4 ). Following concentration, the crude title product was obtained as a viscous yellow material (9.08 g). 1 H NMR (CDCl 3 ): δ 7.22 (m, 25 H), 4.70-4.32 (m, 11 H), 4.00-3.67 (m, 6 H), 3.38-2.49 (m, 55 H), 1.39-1.35 (m, 54 H). 13 C NHR (CDCl 3 ): δ 174.27-169.56 (m), 138.5-136.6 (m), 132.49-127.11 (m), 81.06-80.16 (m), 78.62-76.49 (m), 73.62-69.37(m), 57.62-47.28 (m), 36.9; 27.97. MS (FAB): m/e 1842.1 (MH + ). (i) N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-N-methyl-pentakis(O-benzy)glucamine-carbonylethylenediamine The dimer of Example 9(h) (7.9 g, 4.29 mmol) was dissolved in dichloromethane (80 mL) and cooled to 0° C. Trifluoroacetic acid (80 mL) was added and the solution was stirred at ambient temperature for 1 hour. The solution was concentrated and the process was repeated nine times. After the final deprotection, the solution was concentrated and chased with CH 2 Cl 2 (4×20 mL) and water (4×20 mL). Drying under vacuum yielded the crude title product (10.9 g). 1 H NMR (D 2 O): δ 6.53 (br, 25 H), 4.08-2.37 (m, 72 H). 13 C NMR (D 2 O): δ 126.33, 52.33, 51.05, 50.13, 47.27, 45.68, 40.27. MS (FAB): m/e 1504.5 (MH + ). (j) N,N'-Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-1-(N-methyl-glucaminecarbonyl)-ethylenediamine A solution of the dimer of Example 9(i) (0.86 g, 0.57 mol) in water (20 mL) was treated with glacial acetic acid (5 mL) and Pearlman's catalyst (0.5 g). The mixture was hydrogenated in a Parr hydrogenation apparatus with hydrogen gas at a pressure of 53 psi until no further uptake of hydrogen was observed. The solution was filtered, concentrated and chased with water. The residue was purified by ion exchange chromagraphy using BioRad AG1-X8 resin (100-200 mesh, acetate form) using acetic acid as the eluent (0.05-0.2M) to give 0.42 g (70%) of the title product as a pale yellow solid. 1 H NMR (D 2 O) : δ 3.8 -2.66 (m). 13 C NMR (D 2 O): δ 175.17, 179.46, 172.17-170.77, 72.22-70.61, 63.31, 56.87-48.77, 40.59-35.18. MS (FAD): m/e 1054.6 (MH + ). (k) Synthesis of Bisgadolinium complex of N,N'-bis[1,4,7-tris-(carboxy-methyl)-1,4,7,10-tetraazacyclo-dodecan-10-yl-methylcarbonyl]-1-(N-methylglucamine-carbonyl)ethylenediamine To a solution of the dimeric chelant of Example 9(j) (0.94 g, 0.89 mmol) in water (25 mL) was added gadolinium acetate (0.47 g) and the solution was stirred at 40° C. overnight. It was concentrated and the solution was repeatedly chased with water until the pH was to 5.2. The xylenol orange test for free gadolinium was negative. Further quantities of gadolinium acetate were added in 1 weight % increments and the solution heated at 40° C. for 1 hour until the reaction mixture showed a postive xylenol orange test for gadolinium. The solution was filtered, concentrated, and chased with water. The crude title product was subjected to purification by semi-preparative HPLC on a C18 column using 2% methanol in water, followed by precipitation from a methanol solution with acetone to give 0.78 g (52%). MS (FAB): m/e 1364.3 (MH + ). EXAMPLE 10 Synthesis of bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl]-2-oxo-3-aza-pentane and the Gadolinium and Dysprosium Complexes Thereof (a) 3-Aza-4-oxo-1,5-dibromopentane Bromoethylamine hydrobromide (6.15 g, 30 mmol) was suspended in chloroform (40 mL) and treated with diisopropylethylamine (5.2 mL, 60 mmol). The solution was cooled in a dry ice acetone bath and a solution of bromoacetyl bromide (2.6 mL, 30 mmol) in chloroform (10 mL) was added dropwise under nitrogen. After the addition was complete, the solution was warmed to ambient temperature and stirred overnight. The solution was washed successively with water (2×30 mL), 1M acetic acid (2×30 mL), water (30 mL), 1M NaOH (2×30 mL) and water (2×30 mL). Drying over anhydrous Na 2 SO 4 followed by concentration yielded the crude product as a colorless solid (4.94 g; 66%). Recrystallization from chloroform yielded the pure title product (1.33 g, 18.1%). 1 H NMR (CDCl 3 ): δ 6.84 (br, 1 H), 3.91 (s, 2 H), 3.72 (q, 2 H), 3.5 (t, 2 H). 13 C NMR (CDCl 3 ): δ 166.08, 41.54, 31.11, 28.67. (b) Bis[1,4,7-tris-(tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecan-10-yl]-2-oxo-3-aza-pentane 3-Aza-4-oxo-1,5-dibromopentane (Example 10(a), 1.28 g, 5.22 mmol), the hydrobromide salt of Example 1(b) (6.22 g, 10.44 mmol) and tetramethylguanidine (2 mL, 15.66 mmol) were dissolved in acetonitrile (125 mL) and the solution was heated at 60° C. for 48 hours under nitrogen. The solution was concentrated, the residue was dissolved in chloroform and washed with water. It was dried over anhydrous Na 2 SO 4 and concentrated to yield a brown oil. Petroleum ether extraction followed by concentration of the extract yielded the crude title product (6.26 g). 1 H NMR (CDCl 3 ): 8.8 (br, 1 H), 3.46-2.38 (m, 50 H), 1.28 (s, 54 H). 13 C NMR (CDCl 3 ): δ 172.2-169.84, 80.47, 61.83-47.37, 27.94, 27.9. MS (FAB): m/e 1112.9 (MH + ). (c) Bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl]-2-oxo-3-aza-pentane To a solution of the dimer of Example 10(b) (6.25 g) CH 2 Cl 2 (60 mL) cooled in an ice bath, is added trifluoroacetic acid (60 mL) and the mixture stirred at ambient temperature for 1 hour. The solution is concentrated and the process is repeated nine times. After the final deprotection, the solution is concentrated and chased with CH 2 Cl 2 (3×20 mL) and water (3×20 mL). The residue is passed through BioRad AG1 X-8 ion exchange resin (100-200 mesh, acetate form) and the product eluted with aqueous acetic acid (0.05-0.1M acetic acid). (d) Bisgadolinium complex of bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl]-2-oxo-3-aza-pentane The dimeric chelant of Example 10(c) is dissolved in water and gadolinium acetate is added. The solution is stirred at 40° C. for 2 hours. The pH of the solution is raised from 3 to 5 by adding 0.1M ammonium hydroxide followed by chasing with water. Addition of gadolinium acetate in 1 wt. % increments and heating at 40° C. is continued until a positive xylenol orange test is observed. The solution is then filtered and concentrated. The residue is chased with water and dried under vacuum to obtain the title product. (e) Bis dysprosium complex of bis[1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl]-2-oxo-3-aza-pentane The dysprosium complex is prepared analogously to Example 10(d) using the dimeric chelant of Example 10(c) and a soluble dysprosium(III) salt. EXAMPLE 11 1,8-Bis[4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl]-2,7-dioxo-3,6-diazaoctane (EthylDOTA Dimer) 1,8-Bis[4,7,10-tris(2-ethoxy-2-oxoethyl)-1,4,7,10-tetraazacyclodedec-1-yl]-2,7-dioxo-3,6-diazaoctane (EthylDOTA-hexaethylester Dimer) To a stirred solution of K + DOTA-Triethylester (23.8 g, 0.0453 mol) in 500 mL of anhydrous tetrahydrofuran is added dicyclohexylcarbodiimide (9.33 g, 0.0453 mol) and 1-hydroxybenzotriazole (6.07 g, 0.0453 mol). The suspension is stirred for 15 minutes at ambient temperature and ethylenediamine (1.51 mL, 0.0226 mol) is added. After stirring an additional 24 hours at ambient temperature, the suspension is filtered and the solvents are evaporated. The residue is dissolved in 800 mL of ethyl acetate and is washed with 800 mL of saturated, aqueous sodium bicarbonate. Flash chromatography of the residue affords 18.0 g of EthylDOTA-hexaethylester dimer. (b) 1,8-Bis[4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclodedec-1-yl]-2,7-dioxo-3,6-diazaoctane (EthylDOTA Dimer) To a stirred solution of EthylDOTA-hexaethylester dimer (15.0 g, 0.0163 mol) in 100 mL of tetrahydrofuran is added 200 mL of a 1N sodium hydroxide solution. After stirring at ambient temperature for 4 hours, sufficient Bio-Rad AG50-X8 resin is added to the solution to adjust the pH to 2.2. The suspension is filtered and the filtrate is evaporated and lyophilized to provide the title product (11.5 g). EXAMPLE 12 Experimental Results Gadolinium complexes of a series of dimeric substituted tetraazacyclododecane macrocycles (Table 1) have been synthesized. Their physicochemical properties were studied to evaluate their utility as extracellular fluid MRI contrast agents. The results are presented here. Experimental The DO3A bis(amide) dimer ligands 1-12 shown in Table 1 were prepared by the coupling reaction of DO3A-tri-t-butyl ester with bis(chloroacetamides) of the appropriate diamines, followed by the deprotection of the t-butyl ester groups. The gadolinium complexes were prepared by the reaction of the ligands with Gd(OAc) 3 . Relaxivities were measured in water and in serum (in selected cases) at 40° C. and 20 MHz. Viscosities and osmolalities were measured at concentrations listed in Table 2. Conclusion The favourable physicochemical profiles of the dimeric gadolinium chelates presented here, which include relaxivity, viscosity and osmolality suggest their potential use as new extracellular fluid MRI contrast agents. ______________________________________ ##STR12##Compound No. D*______________________________________1 NHCH.sub.2 CH.sub.2 NH2 N(CH.sub.3)CH.sub.2 CH.sub.2 N(CH.sub.3)3 N(CH.sub.2 CH.sub.2 OH)CH.sub.2 CH.sub.2 N(CH.sub.2 CH.sub.2 OH)4 N(CH.sub.2 CHOHCH.sub.2 OH)CH.sub.2 CH.sub.2 N(CH.sub.2 CHOHCH.sub.2 OH)5 NHCH(CON(CH.sub.3)CH.sub.2 (CHOH).sub.4 CH.sub.2 OH)CH.sub.2 NH ##STR13##7 ##STR14##8 NHCH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 NH9 NHCH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 NH10 N(CH.sub.3)CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 N(CH.sub.3)11 NH(CH.sub.2 CH.sub.2 O).sub.3 CH.sub.2 CH.sub.N H12 ##STR15##______________________________________ TABLE 2______________________________________Physicochemical properties of complexesRelaxivity.sup.a(mM.sup.-1 sec.sup.-1 Viscosity.sup.cGd.sup.-1) Osmolality.sup.b (cPs)Complex r.sub.1 r.sub.2 (mmol/kg) 25° C. 37° C.______________________________________1 4.9 5.6 425 (250) 2.4 1.72 5.6 5.5 323 (200) 2.0 1.43 5.2 4.9 555 (200) 2.1 1.54 5.5 6.2 345 (275) .d .d5 6.1 6.9 1083 (384) .d .d6 5.8 6.6 581 (250) 3.0 2.07 5.1 5.9 474 (250) 2.6 1.88 4.7 4.8 653 (314) 2.8 2.19 4.7 5.7 752 (308) 3.3 2.410 5.0 6.5 635 (278) 2.7 2.011 4.4 5.3 793 (281) 3.4 2.612 5.7 7.1 971 (257) 2.9 2.1______________________________________ .sup.a in water at 40° C. and 20 mHz .sup.b concentrations (mM) in parentheses .sup.c same concentrations as in osmolality unless otherwise stated .sup.d not measured

This invention relates to dichelants, in particular compounds having two macrocyclic chelant groups linked by a bridge containing an ester or amide bond, especially compounds of formula Vb ##STR1## (wherein each X which may be the same or different is NZ, O or S, at least two Xs being NZ; each Z is a group R 1 or a group CR 1 2 Y, at least one Z, and preferably 2 or 3 Zs, on each macrocyclic ring being a group CR 1 2 Y; each Y is a group CO 2 H, PO 3 H, SO 3 H, CONR 1 2 , CON(OR 1 )R 1 , CNS or CONR 1 NR 1 2 , preferably COOH; m is 0 or 1 or 2, preferably 1; each n is 2 or 3, preferably 2; q is 1 or 2, preferably 1; each R 1 which may be the same or different is a hydrogen atom or an alkyl group optionally substituted by one or more hydroxy and/or alkoxy groups; and D is a bridging group having a molecular weight of less than 1000, preferably less than 500, joining two macrocyclic rings via at least one amide or ester bond) and salts and metal chelates thereof.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to bolted joints, for use in low thermal expansion materials, and more particularly to a joint assembly wherein a metallic fastener joins material having a low coefficient of thermal expansion to a material having a high coefficient of thermal expansion. 2. Description of the Related Art With the increasing use of ceramic and other low thermal expansion materials, a problem is encountered when such materials are joined to high thermal expansion materials. Such materials also are typically used in high strength conventional fasteners, such as metallic bolts. Metal fasteners are thermally incompatible with ceramic and other low thermal expansion materials in that the metal expands more than the ceramic material does with an increase in temperature. The coefficient of thermal expansion for metals ranges from 3×10 -6 to 13×10 -6 in./in./°F., with the coefficient of thermal expansion for steel being about 10×10 -6 in./in./°F. On the other hand, ceramic materials have a coefficient of thermal expansion of 1×10 -6 to 2×10 -6 in./in./°F. If a metallic bolt shank is fitted closely within a bore in a ceramic material, cracking of the ceramic material is likely to occur if the joint is exposed to temperature changes. Various bushings are conventionally used for providing a close fit between a shank and a bore through which the shank passes. Two such bushings are disclosed in U.S. Pat. Nos. 4,156,299 and 3,643,290. However, these devices do not address the problem of differential thermal expansions. Other attempts have been made for joining ceramic and metal parts in a manner that compensates for differential thermal expansions. However such joints have proved complex and costly and they do not eliminate thermally induced stress in the materials being joined. The problem of fitting a high thermal expansion fastener in the bore of a low thermal expansion material and the problem of compensating for differential expansions between the high and low thermal expansion materials being joined so that thermal stress does not result upon temperature change has not been addressed. The present invention provides a cost efficient solution to this problem. SUMMARY OF THE INVENTION Accordingly, it is an object of the invention to provide a thermal stress-free joint assembly for joining a high thermal expansion material to a low thermal expansion material by means of a high thermal expansion shank within a bore in the low thermal expansion material. It is another object of the present invention to provide a joint assembly in which a high thermal expansion shank fits closely within a bore in a low thermal expansion material and remains closely fit with temperature changes. It is additionally an object of the invention to provide a joint assembly that does not experience thermally induced stress with temperature change and that can be produced at a cost that is comparable to the cost of conventional bolted joint assemblies. Additional objects and advantages of the present invention will be set forth in part in the description that follows and in part will be obvious from the description or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by the apparatus particularly pointed out in the appended claims. To achieve the objects and in accordance with the purpose of the invention, as embodied and as broadly described herein, a thermal stress-free joint assembly for joining a high thermal expansion material and a low thermal expansion material is provided, comprising: a first member having a bore therethrough, the first member comprised of a first material having a first coefficient of thermal expansion, the bore having a selected cross section; a second member; a fastener comprised of a second material having a second coefficient of thermal expansion, the second coefficient of thermal expansion being greater than the first coefficient of thermal expansion, the fastener including a shank having a selected cross section passing through the bore, the fastener engaging said second member for joining said first and second members; an annular bushing disposed in the bore and having a selected external diameter and a circumferential surface closely engaging the periphery of the bore, an internal circumferential surface closely engaging the shank and at least one frangible portion extending between the external and internal circumferential surfaces, the bushing being comprised of a material having a third coefficient of thermal expansion that is less than the first and second coefficients of thermal expansion, the shank and bore dimensions being selected in accordance with the following equation: D.sub.1 /D.sub.2 =(α.sub.3 -α.sub.1)/(α.sub.3 -α.sub.2) where D 1 =shank cross sectional dimension D 2 =bore dimension α 1 =first member coefficient of thermal expansion α 2 =shank coefficient of thermal expansion. α 3 =bushing coefficient of thermal expansion The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the presently preferred embodiment of the invention and, together with the description, serve to explain the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a joint assembly according to the preferred embodiment of the invention. FIG. 2 is a cross-sectional view of the joint assembly shown in FIG. 1 taken along the line A--A. DESCRIPTION OF THE PREFERRED EMBODIMENT Reference will now be made in detail to a presently preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Throughout the drawings, like reference characters are used to designate like elements. According to the present invention, there is provided a joint assembly 10 which includes a first member 12 having a bore therethrough and a second member 26 having an aperture 38. The first member is comprised of a first material having a first coefficient of thermal expansion α 1 , and the bore has a selected cross sectional dimension. As embodied herein, a first member 12 is comprised of a material having a low coefficient of thermal expansion, as for example, a ceramic material with a coefficient of thermal expansion in the range of about 1×10 -6 to about 2×10 -6 in./in./°F. Second member 26 may also be comprised of a metallic material. Member 12 has a bore 14 formed therethrough. Preferably, bore 14 is a circular cylindrical bore having a diameter shown by dimension line 30 in FIG. 2. According to the present invention, a fastener 15 is provided which is comprised of a second material having a second coefficient of thermal expansion α 2 , the second coefficient of thermal expansion being greater than the first coefficient of thermal expansion α 1 . The fastener has a shank of a selected cross section passing through the bore in the first member and the aperture in the second member. As embodied herein, fastener 15 which may be a bolt includes a head 18 that is integral with shank 16, the latter having a threaded end 17 on which a threaded nut 20 is threadedly engaged. The material of which fastener 15 is made has a coefficient of thermal expansion greater than the coefficient of thermal expansion of member 12. Fastener 15, including shank 16, is preferably made of metal having a coefficient of thermal expansion in the range of about 4×10 -6 to 13×10 -6 in./in./°F. Fastener 15 may be, for example, a conventional metal bolt having a smooth shank 16 and a threaded end 17 on to which a threaded nut 20 is threadedly engaged. Shank 16 has a diameter, as shown by dimension line 32, that is smaller than the diameter of bore 14 as shown by dimension line 30. Shank 16 is disposed within bore 14. According to the invention, there is further provided an annular bushing 21 disposed in the bore 14. Bushing 21 has an external circumferential surface 34 closely engaged by bore 14, an internal circumferential surface 36 closely surrounding shank 16 and a frangible portion 28 extending between said external and internal circumferential surfaces 34 and 36, respectively. The bushing is comprised of a material having a third coefficient of thermal expansion α 3 that is less than the first and second coefficients of thermal expansion. As embodied herein, an annular bushing 21 is provided between shank 16 and member 12. Bushing 21 has an external diameter substantially equal to the diameter of bore 14 shown by dimension line 30 and an internal diameter substantially equal to the diameter of shank 16 shown by dimension line 32. According to the preferred embodiment of the invention, bushing 21 is made of a material having a coefficient of thermal expansion substantially equal to zero. Bushing 21 may be comprised of a carbon matrix with carbon fibers formulated in a manner to achieve a coefficient of thermal expansion equal to zero. According to another embodiment of the invention, bushing 21 is comprised of a material having a coefficient of thermal expansion less than zero. Such a bushing may be comprised of a carbon matrix with carbon fibers formulated to result in a negative thermal expansion material. That is, bushing 21 may be formulated to contract as the temperature of the bushing increases. The frangible portion 28 of bushing 21 is provided to permit bushing 21 to separate when the diameter of shank 16 increases upon thermal expansion. Frangible portion 28 may be formed as a score line 28a that breaks upon the first expansion of shank 16, or may be formed as a gap 28b which is cut completely through bushing 21. More than one frangible portion 28 may be used, and multiple frangible portions may be arranged equally spaced around the circumference of bushing 21. According to the invention the cross-sectional dimensions of the shank and bore have the following relationship: D.sub.1 /D.sub.2 =(α.sub.3 -α.sub.1)/(α.sub.3 -α.sub.2) (1) where D 1 =shank cross sectional dimension D 2 =bore dimension α 1 =first member coefficient of thermal expansion α 2 =shank coefficient of thermal expansion. α 3 =bushing coefficient of thermal expansion According to the preferred embodiment, the shank and bore are circularly cylindrical and the shank and bore dimensions D 1 and D 2 are the diameters of the shank and bore, respectively. The ratio of the diameter of shank 16 as shown by dimension line 32 to the diameter of bore 14 as shown by dimension line 30 equals the ratio of the difference between the coefficient of thermal expansion of the bushing and the coefficient of thermal expansion of the first member to the difference between the coefficient of thermal expansion of the bushing and the coefficient of thermal expansion of the shank. It can be seen in FIG. 2 that the diameter of bore 14 in member 12 as shown by dimension line 30 is substantially equal to the outer diameter of bushing 21. According to another preferred embodiment of the invention, the bushing coefficient of thermal expansion α 3 is approximately equal to zero. In this case the relationship between dimensions D 1 and D 2 is as follows: D.sub.1 /D.sub.2 =α.sub.1 /α.sub.2. (2) By selecting the dimensions of the fastener, bushing and bore according to either of these equations, (1) or (2), shank 16 will fit closely within bore 14 of member 12 both before and after thermal expansion or contraction of shank 16. In addition, the joint assembly 10 will not experience thermal stress because bushing 21 will separate or converge at frangible portion 28 so that the fit between shank 16 and member 12 remains close without an increase in stress on either member 12 or shank 16. Washers 22 and 24 may be made from a material having a coefficient of thermal expansion greater than that of fastener 15 so that as shank 16 elongates with increased temperature, washers 22 and 24 increase in thickness to maintain bolt preload by bearing against head 18 and nut 20. It will be apparent to those skilled in the art that modifications and variations can be made in the joint assembly of this invention. The invention in its broader aspects is, therefore, not limited to the specific details, representative methods and apparatus, and illustrative examples shown and described herein and above. Thus, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

A thermal stress-free joint assembly for joining a low thermal expansion member and a high thermal expansion member uses a fastener and a bushing fitted within a bore in the low thermal expansion member, wherein the fastener and bushing materials are selected to have predetermined coefficients of thermal expansion. The fastener includes a shank which passes through the bore in the low thermal expansion member. The bushing, bore and shank are dimensioned according to a mathematical relationship to maintain a predetermined clearance or preload as the joint undergoes changes in temperature, without damage to either joined member from thermally induced stress.

BACKGROUND 1. Technical Field The invention generally concerns enhancement filtering to improve visibility of blood vessels and more practically to a framework for vessel enhancement filtering in angiography images. 2. Description of the Related Art The common way to interpret vasculature images, e.g. the Magnetic Resonance Angiography (MRA) images, is to display them in Maximum Intensity Projection (MIP) in which the stack of slices is collapsed into a single image for viewing. MIP is performed by assigning to each pixel in the projection the brightest pixel over all slices in the stack. With this type of display, small vessels with low contrast are hardly visible and other organs may be projected over the arteries. FIG. 1 may demonstrate that small vessels tend to resemble background. A vessel enhancement procedure as a pre-processing step for maximum intensity projection display will help to diminish these two limitations. There are a variety of vessel enhancement methods in literature. The simplest one is to threshold the raw data but this makes the segmentation process incorrectly label bright noise regions as vessels and cannot recover small vessels which may not appear connected in the image. Recently, Hessian-based approaches have been utilized in numerous vessel enhancement filters. These filters are based on the principal curvatures, which are determined by the Hessian eigenvalues, to differentiate the line-like (vessel) from the blob-like (background) structures. However, their disadvantage is that they are highly sensitive to noise due to second-order derivatives. Moreover, they tend to suppress junctions which are characterized same as the blob-like structures using the principal curvature analysis. Junction suppression in turn leads to discontinuity of the vessel network. SUMMARY The present invention has been made to solve the above problems occurring in the prior art. There is provided a method for the vessel enhancement filter utilizing the linear directional information present in an image. The method comprises decomposing the input angiography image into directional images T i using Decimation-free Directional Filter Bank (DDFB), removing non-uniform illumination by employing n distinct homomorphic filters matched with its corresponding directional image, enhancing vessels in every directional image, and re-combining all enhanced directional images. Further consistent with the present invention, wherein said DDFB comprises filtering the input angiography image with H 00 (ω 1 , ω 2 ) and H 11 (ω 1 , ω 2 ) hourglass-shaped like passbands, filtering with H 00 (Q T (ω 1 , ω 2 )) and H 11 (Q T (ω 1 , ω 2 )), where T represents transpose and Q is Quincunx downsampling matrix, and filtering with H 00 (R i Q T Q T (ω 1 , ω 2 )) and H 11 (R i Q T Q T (ω 1 , ω 2 )) where R i (i=1, 2, 3, and 4) are resampling matrices. Q = ( 1 1 - 1 1 ) R 1 = ( 1 1 0 1 ) R 2 = ( 1 - 1 0 1 ) R 3 = ( 1 0 1 1 ) R 4 = ( 1 0 - 1 1 ) Output of the vessel enhancement filter for one directional image is Φ ⁡ ( p ) = max σ ∈ S ⁢ ϕ σ ⁡ ( p ) , where p is coordinate (x′,y′), S is a range, and σ is a various scale. The coordinates Ox′y′ is obtained by rotating Oxy by the angle associated with that directional image. φ σ (p) is based on the diagonal values of the Hessian matrix H′ in the coordinates Ox′y′. H ′ = [ ∂ 2 ⁢ I i ∂ x ′2 ∂ 2 ⁢ I i ∂ x ′ ⁢ ∂ y ′ ∂ 2 ⁢ I i ∂ x ′ ⁢ ∂ y ′ ∂ 2 ⁢ I i ∂ y ′2 ] where ∂ 2 ⁢ I i ∂ x ′2 = ∂ 2 ⁢ I i ∂ x 2 ⁢ cos 2 ⁢ θ i + ∂ 2 ⁢ I i ∂ x ⁢ ∂ y ⁢ sin ⁡ ( 2 ⁢ θ i ) + ∂ 2 ⁢ I i ∂ y 2 ⁢ sin 2 ⁢ θ i , ⁢ ∂ 2 ⁢ I i ∂ y ′2 = ∂ 2 ⁢ I i ∂ x 2 ⁢ cos 2 ⁢ θ i - ∂ 2 ⁢ I i ∂ x ⁢ ∂ y ⁢ sin ⁡ ( 2 ⁢ θ i ) + ∂ 2 ⁢ I i ∂ y 2 ⁢ cos 2 ⁢ θ i , ⁢ ∂ 2 ⁢ I i ∂ x ′ ⁢ ∂ y ′ = - 1 2 ⁢ ∂ 2 ⁢ I i ∂ x 2 ⁢ sin ⁡ ( 2 ⁢ θ i ) + ∂ 2 ⁢ I i ∂ x ⁢ ∂ y ⁢ cos ⁡ ( 2 ⁢ θ i ) + 1 2 ⁢ ∂ 2 ⁢ I i ∂ y 2 ⁢ sin ⁡ ( 2 ⁢ θ i ) Specifically, the input image is first decomposed by DDFB into a set of directional images, each of which contains linear features in a narrow directional range. The directional decomposition has two advantages. One is, noise in each directional image will be significantly reduced compared to that in the original one due to its omni-directional nature. The other is, because one directional image contains only vessels with similar directions, the principal curvature calculation in it is facilitated. Then, distinct appropriate enhancement filters are applied to enhance vessels in the respective directional images. Finally, the enhanced directional images are re-combined to generate the output image with enhanced vessels and suppressed noise. This decomposition-filtering-recombination scheme also helps to preserve junctions. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is showing an angiography image with small vessels. FIG. 2 is flowchart showing a method of enhancing blood vessels consistent with the present invention. FIGS. 3A and 3B are showing the frequency responses of hourglass-shaped like filters. FIG. 4A is showing the First stage of DDFB structure. FIG. 4B is showing the Second stage of DDFB structure. FIG. 4C is showing the Third stage of DDFB structure. FIG. 5 is showing the block diagram of the present invention. FIGS. 6A , 6 B, 6 C, 6 D, 6 E, 6 F, 6 G, and 6 H are showing eight demonstrative directional images. FIG. 7A is showing a synthetic image used to evaluating the performance of the present invention. FIGS. 7B , 7 C, and 7 D are showing enhancement results of the Frangi filter, the Shikata filter and the present invention for the input image shown in FIG. 7A . FIGS. 8A , 8 B, and 8 C are showing enhancement results of the Frangi filter, the Shikata filter and the present invention for the input image shown in FIG. 1 . DETAILED DESCRIPTION Embodiment 1 Whereinafter, a embodiment consistent with the present invention will be described with reference to the drawing. The proposed method consists of three steps, as shown in FIG. 2 : First step (step 21 ) is construction of directional images by decomposing input image, second step (step 22 ) is vessel enhancement, and third step (step 23 ) is recombination of enhanced directional images. As shown in FIG. 2 , the decomposing with DDFB (step 21 ), which is the first step of decomposing input angiography image into directional images. Next, removing non-uniform illumination by homomorphic filter and enhancing directional images by appropriate enhancement filters (step 22 ), which is the second step of enhancement filtering to improve visibility of blood vessels. Thereafter, re-combining directional images (step 23 ), which is the third step of re-combining all enhanced directional images. So, the invention is characterized as follows. To enhance vessels in angiography images, input vessel image is decomposed to a set of directional images using DDFB. The non-uniform illumination is removed by employing a homomorphic filter matched with its corresponding directional image. The filtering process is based on the Hessian eigenvalues and filtering process is applied on the set of directional images. Directional Filter Bank (DFB) can decompose the spectral region of an input image into n=2 k (k=1, 2, . . . ) wedge-shaped like subbands which correspond to linear features in a specific direction in spatial domain. One disadvantage of DFB is that the subbands are smaller in size as compare to the size of input image. The reduction in size is due to the presence of decimators. As far as image compression is concerned, decimation is a must condition. However, when DFB is employed for image analysis purposes, decimation causes two problems. One is, as we increase the directional resolution, spatial resolution starts to decrease, due to which we loose the correspondence among the pixels of DFB outputs. The other is, an extra process of interpolation is involved prior to enhancement implementation. This extra interpolation process not only affects the efficiency of whole system but also produces false artifacts which can be harmful especially in case of medical imagery. Some vessels may be broken and some can be falsely connected to some other vessels due to the artifacts produced by interpolation. So a need arises to modify directional filter bank structure in a sense that no decimation is required during analysis section. We suggest to shift the decimators and resamplers to the right of the filters to create the DDFB, which yields directional images rather than directional subbands. This consequently results in elimination of interpolation and naturally fits the purposes of feature analysis. The decomposing step (step 21 ) of applying DDFB comprise as following stages. First stage of filtering the input angiography image with H 00 (ω 1 , ω 2 ) and H 11 (ω 1 , ω 2 ) hourglass-shaped like passbands, Second stage of filtering with H 00 (Q T (ω 1 , ω 2 )) and H 11 (Q T (ω 1 , ω 2 )), where T represents transpose and Q is Quincunx downsampling matrix, and Third stage of filtering with H 00 (R i Q T Q T (ω 1 , ω 2 )) and H 11 (R i Q T Q T (ω 1 , ω 2 )). At first the stage of applying DDFB, construction of first stage of DDFB only requires two filters. Filters at first stage of DDFB are H 00 (ω 1 , ω 2 ) and H 11 (ω 1 , ω 2 ). They have hourglass-shaped like passbands as shown in FIGS. 3A and 3B . FIG. 4A shows the block diagram of the first stage of DDFB. At second the stage of applying DDFB, the filters required for construction of second stage are H 00 (Q T (ω 1 , ω 2 )) and H 11 (Q T (ω 1 , ω 2 )), where T represents transpose and Q is the Quincunx downsampling matrix. Q = ( 1 1 - 1 1 ) - EQUATION ⁢ ⁢ 1 - Spectral regions of directional images obtained after filtering through second stage filter are shown in FIG. 4B . At third the stage of applying DDFB, filters used during the third stage of DDFB are H 00 (R i Q T Q T (ω 1 , ω 2 )) and H 11 (R i Q T Q T (ω 1 , ω 2 )), as shown in FIG. 4C where R i (i=1, 2, 3, and 4) are resampling matrices. R 1 = ( 1 1 0 1 ) ⁢ ⁢ R 2 = ( 1 - 1 0 1 ) ⁢ ⁢ R 3 = ( 1 0 1 1 ) ⁢ ⁢ R 4 = ( 1 0 - 1 1 ) - ⁢ EQUATION ⁢ ⁢ 2 ⁢ - Overall eight different filters are created to be used during the third stage. By using the DDFB, the input image is decomposed to n=2 k (k=1, 2, . . . ) directional images T i . The motivation here is to detect thin and low-contrast vessels (which are largely directional in nature) while avoiding false detection of non-vascular structures. Directional segregation property of DDFB is helpful in eliminating randomly oriented noise patterns and non-vascular structures which normally yield similar amplitudes in all directional images (see FIGS. 6A to 6H ). Before these directional images are enhanced in the next step, they are utilized to efficiently remove non-uniform illumination (NUI), which limits the correct vessel enhancement. One conventional approach to correct NUI is to directly apply homomorphic filtering on the original image. A general image can be characterized by two components: (1) the illumination component, which changes slowly in a neighborhood due to light source characteristics and thus is low-frequency, and (2) the reflectance component, which is determined by the amount of light reflected by the objects and therefore is high-frequency. The homomorphic filter is to suppress the low-frequency component while enhance the high-frequency one. However, the direct application of homomorphic filtering is sometimes unsatisfactory because it may enhance background noise which is normally high-frequency. Tuning the filter parameters in this case suffers from a compromise. The more NUI is removed, the more background noise is enhanced. Differently, we propose employing a homomorphic filter matched with its corresponding directional image as shown in the dash-boundary box in FIG. 5 . This new arrangement provides us a better control on the parameters of individual homomorphic filter. Explaining the second step (step 22 ) of vessel enhancement, we propose removing non-uniform illumination by homomorphic filter. In order to compute the principal curvatures with less noise sensitiveness, it is necessary to align the vessel direction with the x-axis. One possible way is to rotate the directional images. Nevertheless, image rotation requires interpolation which is likely to create artifacts and thus is harmful especially in case of medical imagery. We therefore rotate the coordinates rather than the directional images. Suppose the directional image I i (i=1 . . . n) corresponds to the orientations ranging from θ i,min to θ i,max (counterclockwise angle). Its associated coordinates Oxy will be rotated to Ox′y′ by an amount as large as the mean value θ i . θ i = θ i , min + θ i , max 2 - ⁢ EQUATION ⁢ ⁢ 3 ⁢ - Hessian matrix of the directional image I i in the new coordinates Ox′y′ is determined as followed EQUATION 4. H ′ = [ ∂ 2 ⁢ I i ∂ x ′2 ∂ 2 ⁢ I i ∂ x ′ ⁢ ∂ y ′ ∂ 2 ⁢ I i ∂ x ′ ⁢ ∂ y ′ ∂ 2 ⁢ I i ∂ y ′2 ] ⁢ ⁢ where ⁢ ⁢ ∂ 2 ⁢ I i ∂ x ′2 = ∂ 2 ⁢ I i ∂ x 2 ⁢ cos 2 ⁢ θ i + ∂ 2 ⁢ I i ∂ x ⁢ ∂ y ⁢ sin ⁡ ( 2 ⁢ θ i ) + ∂ 2 ⁢ I i ∂ y 2 ⁢ sin 2 ⁢ θ i , ⁢ ∂ 2 ⁢ I i ∂ y ′2 = ∂ 2 ⁢ I i ∂ x 2 ⁢ sin 2 ⁢ θ i - ∂ 2 ⁢ I i ∂ x ⁢ ∂ y ⁢ sin ⁡ ( 2 ⁢ θ i ) + ∂ 2 ⁢ I i ∂ y 2 ⁢ cos 2 ⁢ θ i , ⁢ ∂ 2 ⁢ I i ∂ x ′ ⁢ ∂ y ′ = - 1 2 ⁢ ∂ 2 ⁢ I i ∂ x 2 ⁢ sin ⁡ ( 2 ⁢ θ i ) + ∂ 2 ⁢ I i ∂ x ⁢ ∂ y ⁢ cos ⁡ ( 2 ⁢ θ i ) + 1 2 ⁢ ∂ 2 ⁢ I i ∂ y 2 ⁢ sin ⁡ ( 2 ⁢ θ i ) - ⁢ EQUATION ⁢ ⁢ 4 ⁢ - The principal curvatures are then defined by the diagonal values of H′. These values are EQUATION 5. PC 1 = 0 ; ⁢ ⁢ PC 2 = y ′2 - ( σ 0 2 + σ 2 ) ( σ 0 2 + σ 2 ) 2 ⁢ I i ⁡ ( x ′ , y ′ ) - ⁢ EQUATION ⁢ ⁢ 5 ⁢ - where σ selected in a range S is the standard deviation of the Gaussian kernel used in the multiscale analysis. Practically, the vessel axis is not, in general, identical to the x′-axis and so PC 1 ≈0. Inside the vessel, |y′|<√{square root over (σ 0 2 +σ 2 )} and thus PC 2 is negative. Therefore, vessel pixels are declared when PC 2 <0 and  PC 1 PC 2  ⁢ ⁢ << ⁢ ⁢ 1. To distinguish background pixels from others, we define a structureness measurement as EQUATION 6. C =√{square root over ( PC 1 2 +PC 2 2 )}  EQUATION 6 This structureness C should be low for background which has no structure and small derivative magnitude. Based on the above observations, the vessel filter output can be defined as EQUATION 7. ϕ σ ⁡ ( p ) = η ⁡ ( PC 2 ) ⁢ exp ( - R 2 2 ⁢ β 2 ) [ 1 - exp ( - C 2 2 ⁢ γ 2 ) ] , - ⁢ EQUATION ⁢ ⁢ 7 ⁢ - where p=(x′,y′), R=PC 1 /PC 2 , β and γ are adjusting constants, and η ⁡ ( z ) = { 0 if ⁢ ⁢ z ≥ 0 ; 1 if ⁢ ⁢ z < 0. The filter is analyzed at different scales σ in a range S. When the scale matches the size of the vessel, the filter response will be maximum. Therefore, the final vessel filter response is EQUATION 8. Φ ⁡ ( p ) = max σ ∈ S ⁢ ϕ σ ⁡ ( p ) - ⁢ EQUATION ⁢ ⁢ 8 ⁢ - One filter (EQUATION 8) is applied to one directional image to enhance vessel structures in it. Explaining the third step (step 23 ) of re-combining directional images, each directional image now contains enhanced vessels in its directional range and is called the enhanced directional image. Denote Φ i (p), i=1 . . . n, as the enhanced directional images. Another advantage of DDFB is that its synthesis is achieved by simply summing all directional images. Thus, the output enhanced image F(p) can be obtained by EQUATION 9. F ⁡ ( p ) = 1 n ⁢ ∑ i = 1 n ⁢ Φ i ⁡ ( p ) - ⁢ EQUATION ⁢ ⁢ 9 ⁢ - The whole filtering procedures can be summarized as follows. First, the input angiography image is decomposed into n=2 k (k=1, 2, . . . ) directional images T i using DDFB. Then, n distinct homomorphic filters are employed to n respective directional images to remove non-uniform illumination. The output uniformly illuminated directional images I i are enhanced according to EQUATION 7 and EQUATION 8. Finally, all enhanced directional images are re-combined to yield the final filtered image F as in EQUATION 9. FIG. 7 shows the results of an synthetic image which was processed by the three filter models. The synthetic image in FIG. 7A is designed to contain vessels of different sizes and junctions of different types. It is possible to see that the Frangi ( FIG. 7B ) and Shikata ( FIG. 7C ) filters unexpectedly suppress junctions while our proposed approach ( FIG. 7D ) does not. The suppressed junctions make vessels discontinuous. It is the use of directional image decomposition that makes the proposed model work. Normally, a vessel has one principal direction, which is mathematically indicated by a small ratio between the smaller and larger Hessian eigenvalue. Meanwhile, at a junction, where a vessel branches off, there are more than two principal directions, and thus the ratio of two eigenvalues is no longer small. As a result, the conventional enhancement filters (e.g., the Frangi and Shikata filters) consider those points as noise and then suppress them. Our proposed approach, on the other hand, decomposes the input image to various directional images, each of which contains vessels with similar orientations. Consequently, junctions do not exist in directional images and so are not suppressed during the filtering process. After that, due to the re-combination of enhanced directional images, junctions are re-constructed at those points which have vessel values in more than two directional images. FIGS. 8A , 8 B, and 8 C respectively show enhancement results of Frangi filter, Shikata filter and our present invention for the input images shown in FIG. 1 . As can be observed, Frangi filter gives good results with large vessels but fails to detect small ones while Shikata model is able to enhance small vessels but unfortunately enhances background noise also. Conversely, our proposed filter can enhance small vessels with more continuous appearances.

Disclosed is a method for enhancing blood vessels in angiography images. The method incorporates the use of linear directional features present in an image, extracted by a Directional Filter Bank, to obtain more precise Hessian analysis in noisy environment and thus can correctly reveal small and thin vessels. Also, the directional image decomposition helps to avoid junction suppression, which in turn, yields continuous vessel tree.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a quadrature modulation circuit. In particular, the present invention relates to a quadrature modulation circuit which includes a base band wave reshaping circuit used for digital modulation such as four phase shift keying modulation (QPSK) in which the frequency band is limited by the digital transmission system. 2. Description of the Prior Art FIG. 8 shows a block diagram of a conventional quadrature modulation circuit used for QPSK. In FIG. 8, an in -phase channel signal 1 i (I-ch) and a quadrature-phase channel signal 1 q (Q-ch) are non-return-to-zero (NRZ) input signals. Low pass filters (ROM LPF) 2 i and 2 q are read only memories (ROM) respectively which operate as band limitation filters for I-ch and Q-ch. Digital to analog converters (D/A converter) 3 i and 3 q convert the digital signals which are received from the ROM LPF 2 i and ROM LPF 2 q , to analog signals. Analog filters 4 i and 4 q suppress the step aliases received from the D/A converters 3 i and 3 q . A quadrature modulation circuit 5 which includes a phase shifter 51, multipliers 52, 53 and an adder 54 modulate a carrier orthogonally with the output signals of the analog filters 4 i and 4 q . An oscillator 6 supplies the modulation carrier signal to the quadrature modulation circuit 5. FIG. 9 shows a block diagram of the low pass filters (ROM LPF) 2 i and 2 q in FIG. 8. In FIG. 9, an input signal 1 corresponds to the in-phase channel signal 1 i (I-ch) and the quadrature channel signal 1 q (Q-ch). An n-step shift register 21 shifts the input signal 1 in sequence. An oscillator 22 generates a clock signal corresponding to the sample frequency of the ROM LPF 2 i and 2 q . A ROM 24 stores the resulting data of the wave form from the filter. FIG. 10 shows another block diagram of the low pass filters (ROM LPF) 2 i and 2 q in FIG. 8. A pair of n/2-step shift registers 211 and 212 shift the first half cycle of the input signal and the second half cycle of the input signal respectively. ROMs 241 and 242 store the different wave forms. An adder 25 adds the values received from the ROMs 241 and 242. The operation of the above conventional art is explained hereinafter. In the digital modulation, such as QPSK, since the frequency component spreads over a wide range, the frequency of the modulated output signal is limited by band limitation filter. A QPSK signal S(t) limited in the base band frequency is expressed in the following equation (1). ##EQU1## where ω c is a carrier frequency, I k and Q k are the digital signals of I-ch and Q-ch and have the value of +1 or -1 and h (t) is the impulse response of the band limitation filter. A nyquist filter having the characteristics of a raised-cosine roll-off is used for the band limitation filter. The operation of FIG. 8 is explained by referring the equation (1). An in-phase channel signal 1 i (I-ch) and a quadrature channel signal 1 q (Q-ch) are inputted to the low pass filters (ROM LPF) 2 i and 2 q respectively by the form of NRZ signal I k and Q k . Input signals I k and Q k are convoluted to form impulse responses in the low pass filters (ROM LPF) 2 i and 2 q respectively. Smoothed wave forms I (t) and Q (t) are outputted as sampled and quantized numerical data from the low pass filters (ROM LPF) 2 i and 2 q respectively. These output data are inputted to the D/A converters 3 i and 3 q respectively and converted into analog signals. The analog filters 4 i and 4 q smooth the step data converted to the analog signals, suppress the aliases generated at the sampling process, and the output signals I (t) and Q (t) are inputted to the quadrature modulator 5. In the quadrature modulator 5, the carrier signal generated in the generator 6 is distributed into two quadrature carriers -sin ω c and cos ω c which is shifted 90 degrees using a shifter 51. These two carrier signals are applied to multipliers 52 and 53 and are multiplied by the output signals I (t) and Q (t) received from the analog filter 4 i and 4 q respectively. The two outputs from the multipliers 52 and 53 are added in an adder 54 and are outputted as a modulation wave form S (t). The operations of the ROMs LPF 2 i and 2 q are explained by using FIG. 9 and FIG. 11. The operation of the LPF can be considered as the convolution of the input signal and the impulse response of the LPF. Therefore, they are expressed as the second and the third equations of equation (1). FIG. 11 shows the convolution result of the equation (1). In FIG. 11, numeral 7 shows input impulse row (I k or Q k ). The upward arrow shows "1" and downward arrow shows "0". 8 is an impulse response wave form [I k ·h(t-kT) or Q k ·h(t-kT)] of the LPF for each input impulse 7. These impulse response wave forms [I k ·h(t-kT) or Q k ·h(t-kT)] are shown in dotted lines. 9 is a filter output wave from [I (t) or Q (t)] in which all impulse response wave forms are added. The filter output wave form [I (t) or Q (t)] is shown in solid line. The range k of Σ is k=-∞ to ∞. As easily known from each impulse response wave form 8 in FIG. 11, the value of the impulse response becomes negligibly small where |k| is very large. Therefore, the impulse response can be restricted within the finite range. In this example, 5 symbols before and 5 symbols after a certain symbol (total symbols are 10) are used for calculating the convolution of the impulse response. In this case, the impulse response wave form between the "5" symbol and "6" symbol shown in the solid line is calculated using 10 symbols shown in FIG. 11. When the convolution is calculated from the finite impulse response, the filter output wave form I (t) or Q (t) is obtained as the summation of all impulse response wave forms corresponding to each 10 symbols. That is, the impulse response wave form between the "5" symbol and "6" is calculated from only 10 symbols of "1" to "10" symbols. FIG. 9 shows a ROM LPF which includes the ROM 24 for storing the wave form described above. In FIG. 9, digital signals I k or Q k (input signal 1) are inputted to the n-step shift register 21. The shift register 21 shifts the input data (symbol) in sequence and stores the most recent n symbols and outputs these n symbols to the address of the ROM 24. In this embodiment, as the 10 symbols are used, n is equal to 10. All combination wave forms of n symbols are calculated beforehand and stored in the ROM 24. In this case, the wave form can not be processed continuously on the time axis. Therefore, the wave forms between two symbols are sampled on the time point of 2 m and the quantized data is stored in the ROM 24. The m bits output from the 2 m binary counter 23 which operates at the sampling clock received from the oscillator 22 is inputted to the ROM 24 as well as the n symbols received from the shift register 21. The ROM LPF in FIG. 9 operates as the LPF by selecting the output wave form stored in the ROM 24 at a time according to the address data constructed of n symbol data received from the shift register 21 and by reading in sequence the b 2 m sampling number between the two symbols which is selected according to the output value from the counter 23. The capacity of the ROM 24 is decided by the referred symbol data n and the sampling number 2 m between the two symbols. For example, in the case of QPSK, as I k and Q k are expressed by one bit respectively, if n=10 and m=3, then the necessary capacity for the ROM 24 is 2.sup.(n+m) =2 13 =8K words respectively for each I-ch and Q-ch ROM. Further, if n becomes larger in order to make the truncation error of the impulse response smaller, the capacity of the ROM will be increasing exponentially. FIG. 10 is a block diagram of ROMs LPF 2 i and 2 q configuration which is able to decrease the required capacity of the ROM 24 of FIG. 9. In FIG. 10, the operation of the low pass filter is modified, and expressed by equation (2) which is introduced from the second and third equations of equation (1) as follows. ##EQU2## In equation (2), the range of the impulse response exists between finite n symbols. The operation of the FIG. 10 is explained using FIG. 12 and equation (2). The filter output wave form is considered as the summation of the filter output wave forms shown in FIGS. 12(a) and (b). That is, the wave form of the FIG. 12(a) indicates the first term of the right side of equation (2) and FIG. 12(b) indicates the second term of the right side of the equation (2). The reference numbers 71˜91 and 72˜92 in FIG. 12 correspond to the number 7˜9 in FIG. 11. The wave forms shown in FIG. 12(a) and (b) are stored in a ROM 241 and 242 of FIG. 10 respectively in the same way as stored in the ROM 24 in FIG. 9. Each n/2 data from the shift registers 211 and 212 and m bit data from the counter 23 are inputted to the ROMs 241 and 242 respectively, and the corresponding data are read from the ROMs 241 and 242 respectively. The two output data from the ROM 241 are added in an adder 25. That is, the ROM 241 operates to calculates the first term of the right side of equation (2), the ROM 241 operates to calculates the second term of the right side of equation (2), and the adder 25 calculates the addition of the right side of equation (2). The n data input is divided into two portions, and the first half n/2 data (k=-n/2˜-1) is stored in the n/2 step shift register 211 and the second half n/2 data (k=0˜n/2 -1) is stored in the n/2 step shift register 212. The address data from the shift register 211 is outputted to the ROM 241, and the address data from the shift register 212 is outputted to the ROM 242. The m bits output from the counter 23 is inputted to the both ROM 241 and 242. The operation of the m bits output is the same as explained in the FIG. 9. The capacity of the ROMs 241 and 242 in FIG. 10 is calculated as follows. For example, if n=10 and m=3, then the capacity of the both ROMs is 2.sup.(n/2+m) ×2=2 8 ×2=512 words. In the case of 16 QAM, 8 PSK and π/4 shifted DQPSK, the capacity of the ROM is 2.sup.(2×n/2+m) ×2=2 13 ×2=16K words. As discussed above, the capacity of the ROM of FIG. 10 becomes smaller than that of FIG. 9. But, the capacity of the ROMs 241 and 242 still occupies a considerable amount of memory in the quadrature modulation circuit of FIG. 8. It is also necessary to provide two sets of the same ROM in the quadrature modulation circuit for each I-ch and Q-ch. There is prior art, for example, laid-open Japanese patent publication No. 63-77246/1988, which describes such quadrature modulation. As the conventional quadrature modulation is constructed as discussed above, it is necessary to provide a large capacity ROM LPF 2 i and ROM LPF 2 q for each I-ch and Q-ch respectively. It is a primary object of the present invention to provide a quadrature modulation circuit which requires small capacity ROMs for operating as filters. It is a further object of the present invention to reduce the hardware size compared with the prior art quadrature modulation circuit having ROMs for operating as filters. It is a further object of the present invention to reduce the ROM size by using the amplitude symmetry of the wave form. It is a still further object of the present invention to reduce the ROM size by using the symmetry of the wave form on the time axis. SUMMARY OF THE INVENTION A quadrature modulation circuit includes at least a low pass filter for limiting the frequency band of the in-phase channel and the quadrature channel, along with at least a D/A converter for converting the digital signals received from the low pass filters to analog signals. The quadrature modulation circuit also includes at least a filter for suppressing the aliases outputted from the D/A converters and a quadrature modulator for modulating the outputs from the filters. In the quadrature modulation circuit, the low pass filters operate by a time division sequence for the inphase channel and the quadrature channel. The low pass filters also use one symbol as a sign data and invert the sign of the remaining symbol data and that of the data read out from the ROM. The low pass filters divide the reference data into the first half portion and the second half portion, and read out of the contents from the ROM for the forward direction of the time axis at the first half portion, and for the backward direction of the time axis at the second half portion. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows a block diagram of a first embodiment of a quadrature modulation circuit of the present invention. FIG. 2 shows a block diagram of a construction of a ROM LPF of the embodiment of FIG. 1. FIG. 3 shows the symmetrical signal wave form on the time axis. FIG. 4 shows the symmetrical signal wave form in terms of amplitude. FIG. 5 shows a block diagram of a second embodiment of a quadrature modulation circuit of the present invention. FIG. 6 shows a block diagram of a third embodiment of a quadrature modulation circuit of the present invention. FIG. 7 shows a block diagram of a construction of the ROM LPF of FIG. 6. FIG. 7b shows a block diagram of another construction of the ROM LPF of FIG. 6. FIG. 8 shows a block diagram of a conventional quadrature modulation circuit. FIG. 9 shows a block diagram of a construction of a ROM LPF of FIG. 8. FIG. 10 shows a block diagram of another construction of a ROM LPF of FIG. 8. FIG. 11 shows the wave form of the ROM of the FIG. 9. FIG. 12 shows the wave form of the ROM of the FIG. 10. FIG. 13 shows a time chart which gives wave forms for some points in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of the present invention. In FIG. 1, signals 1 i and 1 q are inputted signals of I-ch and Q-ch respectively. A selector 10 switches the input signals 1 i and 1 q to a ROM 20 by a time division process. A ROM 20 is a ROM LPF which stores a half of the wave form data using the symmetry characteristic of the wave form data. The adoption of the ROM LPF decreases the capacity of the memory. A demultiplexer 11 demultiplexes the output signal from the ROM 20 by a time division process. D/A converters 3 i and 3 q convert the input digital signals into analog signals for the I-channel and the Q-channel respectively. Analog filters 4 i and 4 q smooth the analog signals, suppress the aliases generated at the sampling process, and output I (t) and Q (t) signals to the quadrature modulator 5 respectively. A quadrature modulator 5 modulates the input I (t) and Q (t) signals with the distributed two signals in the same manner as explained in FIG. 8. An oscillator 6 supplies the modulation carrier signal to the quadrature modulator 5. FIG. 2 shows a block diagram of the selector 10 and the ROM LPF 20 of FIG. 1. In FIG. 2, n/2 step shift registers 211 i , 211 q , 212 i and 212 q shift the input 1 i and 1 q signals in sequence respectively. A selector 100 selects one of the outputs from the shift registers 211 i , 211 q , 212 i and 212 q . Exclusive ORs 202 and 204 operate so that the amplitude symmetry of the wave form is used for calculating the output signal. Exclusive OR 203 operates so that the symmetry of time axis of the wave form is used for calculating the output signal. A ROM 201 is addressed by the outputs of the exclusive ORs 202 and 203 and outputs the data to an exclusive OR 204. An adder 251 adds the output from the exclusive OR 204. A latch circuit 206 latches the output from the adder 251 and uses it for the succeeding addition. An oscillator 221 generates a clock signal which is supplied to a counter 231 for counting the clock. A timing generator 207 generates the latch clock signal (CK) and clear signal (CLR) for the latch circuit 206 from the clock signal received from the counter 231. The operation of the first embodiment is explained hereinafter using FIG. 1 and FIG. 2. In FIG. 1, signals 1 i and 1 q are inputted to the selector 10. The selector 10 switches the input signals 1 i and 1 q to the ROM LPF 20 by a time division process. The ROM LPF 20 stores the filtered wave form data. Needed memory of which is reduced by utilizing the symmetric characteristics of the wave form. The same ROM LPF 20 is used both for the in-phase channel and the quadrature channel by a time division process. The demultiplexer 11 demultiplexes the output signal from the ROM LPF 20 and sends it to the D/A converters 3 i and 3 q by a time division process. Each D/A converter 3 i and 3 q converts the input digital signal into an analog signal. Each analog filter 4 i and 4 q smoothes the analog signal, suppresses the aliases generated at the sampling process, and outputs I (t) and Q (t) signals to the quadrature modulator 5 respectively. The quadrature modulator 5 modulate a carrier orthogonally with the output signals of the analog filters 4 i and 4 q . More detailed explanation is made in connection with the ROM LPF 20 of FIG. 1 using FIG. 2, FIG. 3, FIG. 4 and FIG. 13. Firstly, it is explained how the required capacity of the ROM is reduced by half compared with the prior art using the symmetry characteristic of the signal wave form on the time axis. FIG. 3 shows the symmetrical characteristic of the signal wave form on the time axis. Numerals 73 and 74 are inputted impulse rows respectively, and numerals 83 and 84 are impulse responses for each input impulse. Numerals 93 and 94 are outputted signal wave forms from the filter which are obtained as the summation of all impulse responses 83 and 84 respectively. As discussed above, in the conventional art, it is necessary to provide the ROMs 241 and 242 for storing the first half n/2 symbols and the second half n/2 symbols respectively. But, the data stored in the ROM 241 is the same as the data stored in the ROM 242 in which the data address is reversely arranged. FIG. 3(a) shows the wave form which is read out from the ROM 241 of FIG. 10 at the case of n=10 and the first half five bits are "01011". On the other hand, FIG. 3(b) shows the wave form which is read out from the ROM 242 of FIG. 10 for the case of n=10 and where the second half five bits are "11010". Comparing the two wave form, it is apparent that, if the time axis is reversed, FIG. 3(b) becomes the same as FIG. 3(a). That is, the wave form of the FIG. 3(b) can be obtained by changing the data sequence from "11010" to "01011", and by reversing the counter number which indicates the sampling position, namely by reversing the time axis and reading out the wave form from the ROM 241. As discussed above, by changing the address data, the wave forms of FIG. 3(a) and FIG. 3(b) can be read out from the same ROM 201 as shown in FIG. 2. Secondly, it is explained that the required capacity of the ROM is reduced by half compared with the prior art using the amplitude symmetry of the wave form of FIG. 4. FIG. 4 shows the wave form which explains the amplitude symmetry. In FIG. 4, numbers 75 and 76 are inputted impulse sequences respectively, and numbers 85 and 86 are impulse responses for each input impulse. Numbers 95 and 96 are the output signal wave forms of the filter which convolutes the impulse responses 85 and 86 respectively. FIG. 4(a) shows the wave form which is read out from the ROM 241 of FIG. 10 for the case of n=10 and where the first half five bits are "01011". On the other hand, FIG. 4(b) shows the wave form which is read out from the ROM 241 of FIG. 10 for the case of n=10 and where the first half five bits are "10100" which is the reversed wave form of the FIG. 4(a). Comparing the two wave forms, it is apparent that, by multiplying by (-1), these wave forms are easily transformed each other. The operation for multiplying the wave form by (-1) is attained by inverting each bit and adding 1 to the inverted bits in the case of the two's compliment of the binary. Further, in the case where the wave form is expressed by the sign bit and the absolute value of the remaining bits, the inversion of the amplitude of the wave form is attained only by inverting the sign bit. As explained above, the operation for multiplying by (-1) is attained easily by simple hardware. Therefore, the required capacity of the ROM is reduced by half by storing the half wave form in the ROM shown in FIG. 4(a), and by multiplying the output wave form by (-1). The method for reversing the amplitude symmetry wave form is explained hereinafter. For example, the data on the time axis "5" in FIG. 4(a) is continuously supervised, and if the data on the time axis "5" is "0", then the data of the time axis "1"˜"4" are supplied to the ROM 201 as the address data, and if the data on the time axis "5" is "1", then the data of the time axis "1"˜"4" are inverted and supplied to the ROM 201 as the address data. The read out data from the ROM 201 is multiplied by (-1) in the exclusive OR 204. In FIG. 2, the above two symmetry (time axis and amplitude) process and time division process for I channel and Q channel is used. Therefore, the required capacity of the ROM is reduced by one eighth in comparison with the conventional ROM filter. The operation of FIG. 2 is explained hereinafter. In FIG. 2, the first half of the input signal 1 i is stored in the register 211 i and the second half of the signal 1 i is stored in the register 212 i in the same way as described in FIG. 10. The first half of the input signal 1 q is stored in the register 211 q and the second half of the signal 1 q is stored in the register 212 q . The first n/2 symbols are obtained from the register 211 i and 211 q , and the second n/2 symbols are obtained from the registers 212 i and 212 q . A selector 100 selects the input signal from the registers 211 i , 211 q , 212 i and 212 q by the combination of the control signal S 1 and S 0 . FIG. 13 shows a time chart which gives wave forms of the signals S 1 , S 0 , latch clock signal CK and clear signal CLR in FIG. 2 and the timing relation between them. Latch clock signal CK and the clear signal CLR are generated in the timing generator 207 of FIG. 2. The select signal S 1 switches the I channel and Q channels at a sampling point. The select signal S 0 switches the first half symbols and the second half symbols of the I channel and the Q channel at a sampling point. That is, the output of the register 211 i is selected when S 1 and S 0 are (00), and the output of the register 212 i is selected when S 1 and S 0 are (01). In the same way, the output of the register 211 q is selected when S 1 and S 0 are (10) and the output of the register 212 q is selected when S 1 and S 0 are (11). When the select signal S 0 is 1, the outputs from the register 212 i and 212 q are reversed in order, and also each bit of the output of the time counter 231 is inverted by the select signal S 0 (=1) which is inputted to the exclusive-OR 203. The above reverse of the register 212 i and the register 212 q is executed by changing the connection between the registers 212 i , 212 q and the selector 100. As discussed above, the symmetry of the wave form on the time axis is attained. The output data selected by the select signal S 1 and S 0 is separated to a specific bit symbol for indicating the sign of the wave form and the remaining (n/2-1) bit symbols in order to use the symmetry characteristic of the amplitude of the wave form. These remaining (n/2-1) bit symbols are inputted as the address input to the ROM 201. The sign bit is inputted to the exclusive-OR 202 which inverts the address data. Further, the sign bit is inputted to an exclusive-OR 204 and an adder 251. The output data is processed as two's compliment. Multiplication by (-1) is executed at the exclusive-OR 204 and at the adder 251 by applying "1" to the least significant carry bit. In FIG. 2, the impulse response of the first half of the wave form and the impulse response of the second half of the wave form are processed by time division process. Therefore the output of the I channel and Q channel can not be added at a time as shown in FIG. 10. In this circuit, the addition in the adder 251 is executed as follows. Firstly, a latch circuit 206 is cleared by the clear pulse CLR received from the timing generator 207 before the first half of the wave form is read out from the ROM 201. After the first half of the wave form is read out from the ROM 201, the latch circuit 206 stores the read out first half of the wave form. Secondly, the second half of the wave form is read out from the ROM 201. The output from the adder 251 shows the addition result of the first half and the second half of the wave form. As a result, the output wave form processed by the ROM LPF is obtained from the adder 251. FIG. 5 shows a block diagram of a second embodiment of a quadrature modulation circuit of the present invention. In FIG. 5, a D/A converter 30 is provided which operates by a time division process for I channel and Q channel. The output analog signal from the D/A converter 30 is sampled alternately by the sample hold circuits 12i and 12q, demultiplexed into the I channel and the Q channel. The sample hold circuits 13i and 13q operate by the same timing, and align the phase of the I channel and the Q channel. The other operations are the same as those described in FIG. 1. Therefore the detailed description is omitted. The above embodiments are described using QPSK, but they may also be applied using other forms of modulation, such as 8 PSK, π/4 shifted DQPSK and QAM. The advantages of the other applications are the same as with the present embodiments. FIG. 6 shows a block diagram of a third embodiment of a quadrature modulation circuit of the present invention which is applied to the Gaussian filtered minimum phase shift keying modulation (GMSK). In FIG. 6, the same reference numbers as used in FIG. 1 are used to refer to the same portions or the corresponding portions. Accordingly the detailed explanation of such portions is omitted in connection with the same reference numbers. In FIG. 6, a signal 101 is inputted to a ROM LPF 20. An adder 14 adds the signal from the ROM LPF 20. A latch 15 stores the output signal from the adder 15 which is then added to the succeeding output from the ROM LPF 20. A COS ROM 16 and a SIN ROM 17 convert the output phase from the adder 14 to I channel signal and Q channel signals respectively. In the case of GMSK, input signal 101 is smoothed in the ROM LPF 20. The output signal from the ROM LPF 20 is integrated in sequence by the adder 14 and the latch 15, and the signal in the frequency domain is converted into the signal in the phase domain. After that, the outputs from the COS ROM 16 and the SIN ROM 17 are converted to analog signals in the D/A converter 3 i , 3 q and supplied to the quadrature modulator 5 through LPF 4 i and 4 q . FIG. 7 shows a detailed block diagram of the construction of the ROM LPF 20 of FIG. 6 using amplitude symmetry characteristic. In FIG. 7, numeral 2010 is a ROM, numeral 2040 is a calculator which multiplies the output from the ROM 2010 by (-1) selectively. In FIG. 7, the same reference number to the FIG. 2 and FIG. 9 is the same portion or the corresponding portion. Accordingly the detailed explanation of the portion is abbreviated in connection with the same number. The operation of the embodiment of FIG. 7 is explained hereinafter. The input signal 101 is stored in a shift register 21. One bit of the output signal from the shift register 21 is used as a sign bit and applied to the exclusive-OR 202 and the calculator 2040. The sign bit (1 bit) and the remaining (n-1) bits from the shift register 21 are inputted into the exclusive-OR 202. The remaining (n-1) bits are used as address bits. As discussed above, the output signal from the ROM 2010 is multiplied by (-1) in the calculator 2040 when the sign bit is "1". In this manner, the required capacity of the ROM is reduced by half using amplitude symmetry characteristic. FIG. 7b shows a detailed block diagram of the construction of the ROM LPF 20 of FIG. 6 using the symmetry on the time axis. In FIG. 7b, 1001 is a selector which selects one of the outputs from the shift registers 211,212. 2011 is a ROM. 2211 is a generator which generates the clock signal. 2311 is a counter which counts the clock signal. 2071 is a timing generator which generates a latch clock and a clear signal. In FIG. 7b, the same reference numbers as used in FIG. 2 are used to refer to the same portions or corresponding portions. Accordingly the detailed explanation of such portions is omitted in connection with the same reference numbers. The operation of the embodiment of FIG. 7b is explained hereinafter. The input signal 101 is stored in shift registers 211 and 212. The first half n/2 symbols of the input signal 101 is stored in the shift register 211 and the second half n/2 symbols of the input signal 101 is stored in the shift register 212. The select input signal S 0 selects the first half n/2 symbols or the second half n/2 symbols, that is, the output of the register 211 or 212. When the select input signal S 0 is "1", the selector 1001 selects the second half n/2 symbols from the register 212. In order to use symmetry on the time axis, the output from the register 212 is reversed and the counter data from the counter 2311 is also inverted in the exclusive-OR 203 by the S 0 bit as explained in connection with FIG. 2. The impulse responses of the first half wave form and the second half wave form are read from the ROM 2011 by time division process. The output data from the ROM 2011 is added in the same way using the adder 251 and the latch 206 as described in connection with FIG. 2. As a result, the filter output wave form is obtained from the output of the adder 251. In this manner, the required capacity of the ROM is reduced by half using symmetry wave form on the time axis. The above embodiment are described for applying GMSK, but it may be applied to the tamed FM and other digital FM modulation systems. The advantages of the other applications are the same as in this embodiment.

A quadrature modulation circuit includes a low pass filter which operates by a time division process for the in-phase channel and quadrature-phase channel, and reduces address requirements data using amplitude symmetry of the wave form and/or using symmetry wave form on the time axis. The capacity of the ROM is reduced by half or more and the configuration of the quadrature modulation circuit is simplified.

[0001] The present application is related to and claims, under 35 USC §119(e), the benefit of U.S. Provisional Patent Application Ser. No. 60/732,847, filed Nov. 2, 2005, which is entirely expressly incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] Many cell types in the body can remove apoptotic and cellular debris from tissues; however, the professional phagocyte, or antigen presenting cell (“APC”), has a high capacity to do so. The recognition of apoptotic cells (“ACs”) occurs via a series of evolutionarily-conserved, AC-associated molecular-pattern receptors (“ACAMPRs”) on APCs that recognize and bind corresponding apoptotic-cell-associated molecular patterns (“ACAMPs”). These receptors recognize ligands such as phosphotidyl serine and oxidized lipids found on apoptotic cells. Savill et al. (2002); and Gregory et al. (2004). [0003] Both in vitro and in vivo that AC clearance by APCs in vivo regulates immune responses. Savill, et al. (2002). This immune modulation appears to occur primarily via an alteration of APC function with several hallmarks of a tolerance-inducing APC. These tolerogenic APCs induce tolerance via a variety of mechanisms including the generation of regulatory T cells (“Tregs”). [0004] Tregs comprise a heterogeneous group of T lymphocytes, which actively inhibit immune responses. Groux et al. (1997); Sakaguchi et al. (2001); and Roncarolo et al. (2001). There is the potential to develop Treg therapies for a variety of diseases. [0005] One way to generate Tregs in vivo is via the infusion of ACs. There is evidence from both animal models and human treatments that AC infusion, such as happens during extracorporeal photophoresis (“ECP”), induces Tregs. Maeda et al. (2005); Lamioni et al. (2005); Aubin et al. (2004); Mahnke et al. (2003); and Saas et al. (2002). [0006] Other methods to generate Tregs ex vivo include exposing T cells to a variety of substances including: IL-10 (Roncarolo et al. (2001); and Zeller et al. (1999)); TGFβ (Zheng et al. (2004); Gray et al. (1998); Horwitz et al. (1999); Ohtsuka et al. (1999a); Ohtsuka et al. (1999b); Stohl et al. (1999); Gray et al. (2001); Horwitz, (2001); Yamagiwa et al. (2001); Horwitz et al. (2002); and Zheng et al. (2002)); αMSH (Luger et al. (1999); Taylor (2005); Namba et al. (2002); Nishida et al. (1999); Nishida et al. (2004); Streilin et al. (2000); Taylor et al. (1992); Taylor et al. (1994a); Taylor et al. (1994b); Taylor et al. (1996); Taylor (1999); Taylor (2003); and Taylor et al. (2003)); vitamin D3 (Willheim et al. (1999); Penna et al. (2000); Pedersen et al. (2004); May et al. (2004); Koren et al. (1989); Gregori et al. (2001); Cobbold et al. (2003); and Barrat et al. (2002)); dexamethasone (Pedersen et al. (2004); Barrat et al. (2002); and O'Garra et al. (2003)); and purification (Earle et al. (2005); Schwarz et al. (2000); Chatenoud et al. (2001); Tang et al. (2004); and Masteller et al. (2005)). [0007] Autoimmune diseases involve inappropriate activation of immune cells that are reactive against self tissue. These activated immune cells promote the production of cytokines and autoantibodies involved in the pathology of the diseases. Other diseases involving T-cells include Graft versus Host Disease (GVHD) which occurs in the context of transplantation. In GVHD donor T-cells reject recipient's tissues and organs by mounting an attack against the recipient's body. A host of other diseases involve disregulation of the host immune system. Some are best treated with pharmaceuticals, some with biologicals, others with treatments such as extracorporeal photophoresis (ECP), and yet others have very limited treatment options. [0008] ECP has been shown to be an effective therapy in certain T cell-mediated diseases. In the case of GVHD, photopheresis has been used as a treatment in association with topical triamcinolone ointment, antifungal, antiviral, antibiotics, inimunoglobulins, and methotrexate. ECP has also been used with immunosuppressive agents such as mycophenolate mofetil, tacrolimus, prednisone, cyclosporine, hydroxychloroquine, steroids, FK-506, and thalidomide for chronic GVHD (“cGVHD”) and refractory cGVHD. For solid organ transplants, ECP has been used in conjunction with immunosuppressive agents to reduce the number of acute allograft rejection episodes associated with renal allografts and cardiac tranplants. For example, ECP has been used with OKT3 and/or the immunosuppressive agents prednisone, azathioprine, and cyclosporine to reverse acute renal allograft rejection. ECP has also been used with cyclophosphamide, fractionated total body irradiation, and etoposide for allogeneic marrow transplantation for acute myeloid leukemia, acute lymphoblastic leukemia, chronic myeloid leukemia, non-Hodgkin's lymphoma,; or severe aplastic anemia. SUMMARY OF THE INVENTION [0009] Ex vivo incubation with leukocytes in an allogeneic system leads to generation of T cells with regulatory activity. This generates regulatory T cells (“Treg cells” or “T regs”) with activity to suppress immune responses against the alloantigen. [0010] In an antigen specific and polyclonal activation systems an antigen specific result can be obtained by adding antigen or other stimulation with autologous apoptotic cells. (“ACs”). [0011] The present invention encompasses a method of generating T cells with regulatory activity (T regs) by incubating leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0012] The present invention encompasses compositions of a population of T cells with regulatory activity (T regs) obtained by incubating leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0013] The present invention encompasses a method of treating autoimmune disorder or ameliorating one or more symptoms thereof, by administering to a patient in need thereof an effective amount of a composition of a population of T cells with regulatory activity (T regs) obtained by incubating autologous leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0014] The present invention encompasses a method of treating atopic disease or ameliorating one or more symptoms thereof by administering to a patient in need thereof an effective amount of a composition of a population of T cells with regulatory activity (T regs) obtained by incubating autologous leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0015] The present invention encompasses a method of administering to a transplant recipient an effective amount of a composition of a population of T cells with regulatory activity (T regs) obtained by incubating autologous leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0016] The present invention encompasses a method of administering to a GVHD patient an effective amount of a composition of a population of T cells with regulatory activity (T regs) obtained by incubating autologous leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0017] The present invention encompasses a method of treating patient with a disorder or the predisposition for a disorder by testing the patient to determine whether the patient has a disorder, and administering to a patient in need thereof an effective amount of a composition of a population of T cells with regulatory-activity (T regs) obtained by incubating autologous leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). BRIEF DESCRIPTION OF THE DRAWINGS [0018] FIG. 1 is a schematic showing A: Treg Generation; B: After T regulatory cells are generated, Treg cells placed into MLR. [0019] FIG. 2 shows that regulatory T Cells generated via Co-incubation with ECP-treated PBMCs inhibit the proliferation of syngeneic T Cells [0020] FIG. 3 shows that regulatory T Cells generated via co-incubation with ECP-treated PBMCs inhibit T Cell proliferation better than standard Tr1 cells. [0021] FIG. 4 shows that generation of Regulatory T Cells via co-incubation with ECP-treated PBMCs can be reversed through the addition of lnterleukin-2. [0022] FIG. 5 shows that suppressive activity of regulatory T cells generated via co-incubation with ECP-treated PBMCs is contact-dependent. DETAILED DESCRIPTION Ex Vivo Generation of Tregs Using ACs [0023] The systems that occur in vivo to generate Tregs are quite complex and rely on a series of cell types and morphologic location. Nevertheless, the present invention shows that it is possible to generate these cells in vitro under the conditions described herein. Ex vivo incubation with leukocytes in an allogeneic system leads to generation of T cells with regulatory activity. This generates regulatory T cells (“Treg cells”) with activity to suppress immune responses against the alloantigen, important in a wide variety of disorders including, without limitation, autoimmune diseases, graft versus host disease (“GVHD”),and solid organ transplantation. In an antigen specific and polyclonal activation systems an antigen specific result can be obtained by adding antigen or other stimulation with autologous apoptotic cells (“ACs”). [0024] This ex vivo production method offers several advantages over the drug-induced methods previously described. Importantly, the possible toxic and non-natural effects of these added molecules are avoided. [0025] In addition, there are advantages to ex vivo generation over the in vivo utilization of apoptotic cells including, without limitation, increased control over the number, activity and function of these cells. This therapeutic control provides improved patient treatment protocols. [0026] Generating T regs using a series of methods such as purification, activation, and addition of differentiation factors such as TGFβ, αMSH, anti-CD46, IL-10, vitamin D 3 and dexamethasone has proven that these cells can be generated ex vivo. Apoptotic cells provide a more “in vitro-like” method to induce these cells by generating tolerogenic APCs. [0027] The present invention encompasses a method of generating T-cells with regulatory activity (T regs) by incubating leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0028] The present invention encompasses compositions of a population of T cells with regulatory activity (T regs) obtained by incubating leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0029] The present invention encompasses a method of treating autoimmune disorder or ameliorating one or more symptoms thereof, by administering to a patient in need thereof an effective amount of a composition of a population of T cells with regulatory activity (T regs) obtained by incubating autologous leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0030] Autoimmune disorders include, without limitation, acute transverse myelitis, alopecia areata, Alzheimer's disease, amyotrophic lateral sclerosis, ankylosing spondylitis, antiphospholipid syndrome, atherosclerosis, autoimmune Addison's disease, autoimmune hemolytic anemia, Behcet's disease, bullous pemphigoid, cardiomyopathy, celiac sprue-dermatitis, Cerebellar Spinocerebellar Disorders, spinocerebellar degenerations (spinal ataxia, Friedreich's ataxia, cerebellar cortical degenerations), chronic alcoholism, alcohol-induced hepatitis, autoimmune hepatitis, chronic fatigue immune dysfunction syndrome (CFIDS), chronic inflammatory bowel disease, chronic inflammatory demyelinating polyneuropathy, Churg-Strauss syndrome, cicatricial pemphigoid, cold agglutinin disease, CResT syndrome, Creutzfeldt-Jakob disease, Crohn's disease, Dejerine-Thomas atrophy, Dementia pugilistica, diabetes mellitus, Diffuse Lewy body disease, discoid lupus, disorders of the basal ganglia, disseminated intravascular coagulation, Down's Syndrome in middle age, drug-induced movement disorders, essential mixed cryoglobulinemia, fibromyalgia-fibromyositis, graft versus host disease, Graves' disease, Guillain-Barré´ syndrome, Hallerrorden-Spatz disease, Hashimoto's thyroiditis, Huntington's Chorea senile chorea, idiopathic pulmonary fibrosis, idiopathic thrombocytopenia purpura (ITP), IgA nephropathy, infantile or juvenile spinal muscular atrophy, insulin dependent diabetes, juvenile arthritis, Kawasaki's pathology, lesions of the corticospinal system, Leukemias, Hodgkin's lymphoma, non-Hodgkin's lymphoma, lichen planus, Ménière's disease, mixed connective tissue disease, multiple sclerosis, multiple systems degenerations (Mencel, Dejerine-Thomas, Shy-Drager, Machado-Joseph), myasthenia gravis, neurogenic muscular, Parkinson's disease, pemphigus vulgaris, pernicious anemia, polyarteritis nodosa, polychondritis, polyglandular syndromes, polymyalgia rheumatica, polymyositis dermatomyositis, primary agammaglobulinemia, primary biliary cirrhosis, Progressive supranuclear palsy, psoriasis, Raynaud's phenomenon, Reiter's syndrome, rheumatic fever, rheumatoid arthritis, sarcoidosis, scleroderma, Senile Dementia of Lewy body type, Sjögren's syndrome, stiff-man syndrome, Subacute sclerosing panencephalitis, systemic disorders (Refsum's disease, abetalipoprotemia, ataxia, telangiectasia, mitochondrial multi-system disorder), systemic lupus erythematosus (SLE), Takayasu arteritis, temporal arteritis/giant cell arteritis, thyroidosis, ulcerative colitis, uveitis, vasculitis, vitiligo, Wegener's granulomatosis, Wernicke-Korsakoff. syndrome. [0031] The present invention encompasses a method of treating atopic disease or ameliorating one or more symptoms thereof by administering to a patient in need thereof an effective amount of a composition of a population of T cells with regulatory activity (T regs) obtained by incubating autologous leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0032] Atopic disorders include, without limitation, chronic inflammatory pathologies and vascular inflammatory pathologies, including chronic inflammatory pathologies such as sarcoidosis, chronic inflammatory bowel disease, ulcerative colitis, and Crohn's pathology and vascular inflammatory pathologies, such as, but not limited to, disseminated intravascular coagulation, atherosclerosis, and Kawasaki's pathology. [0033] The present invention encompasses a method of administering to a transplant recipient an effective amount of a composition of a population of T cells with regulatory activity (T regs) obtained by incubating autologous leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0034] The present invention encompasses a method of administering to a GVHD patient an effective amount of a composition of a population of T cells with regulatory activity (T regs) obtained by incubating autologous leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0035] The present invention encompasses a method of treating patient with a disorder or the predisposition for a disorder by testing the patient to determine whether the patient has a disorder, and administering to a patient in need thereof an effective amount of a composition of a population of T cells with regulatory activity (T regs) obtained by incubating autologous leukocytes with autologous apoptotic peripheral blood mononuclear cells (ACs). [0036] T regs can be administered to the patient according to a schedule including, without limitation, two days, one week prior to the transplantation; three days, one week prior to harvesting said transplant; two days a week for two weeks prior to the transplantation; and three days a week for three weeks prior to the transplantation. [0037] Effective amounts of T regs for use in the methods of treatment of the present invention to obtain the required clinical benefit in a subject may vary depending on the source of cells, the subject's condition, the age and weight of the subject and other relevant factors, which are readily determinable by well-known methods. Preferably, the number of T regs administered to a patient are about 1×10 5 /kg to about 1×10 7 /kg. More preferably, the number of T regs administered to a patient are about 1×/10 6 kg. [0038] The method of the present invention encompasses incubating the ACs and leukocytes for a time and under conditions sufficient to generate T regs. Incubation can be under any condition known in the art to be suitable for leukocytes and for about 1 to about 14 days. Preferably, incubation is for about 8 days. [0039] The method of the present invention can further include selecting leukocytes expressing CD4 to obtain CD4+ cells. Preferably, thee cells are CD4+. [0040] The method of the present invention includes incubation at any suitable concentration f ACs and CD4+ cells. Preferably, the cells are at about a 1:10 to about a 10:1 ratio of CD4+:ACs. More preferably, the cells are at a 2:1 to about a 1:2 ratio of CD4+:ACs. [0041] The ACs of the present invention are obtained by an apoptosis-inducing treatment known in the art. Preferably, the apoptosis-inducing treatment is an ECP procedure that employs a photoactivatable compound together with light of a wavelength that activates the photoactivatable compound. Preferably, the photoactivatable compound is a psoralen and the light is UVA. Preferably, the psoralen is 8-MOP. [0042] The method of the present invention can include the incubation with added factors that further enhance generation or function of the T regs. Suitable factors include, without limitation, are hormones, proteins, drugs or antibodies. Preferably, the factors include, without limitation, one of TGFβ, αMSH, anti-CD46, IL-10, vitamin D 3 , dexamethasone, rapamycin and IL-2. Preferably, the factor is IL-10. Preferably, the IL-10 is present at a concentration of about 1 ng/ml to about 100 ng/ml. Preferably, the IL-10 is present at a concentration of about 20 ng/ml. [0043] The method of the present invention includes adding an antigen to the incubation to generate Tregs which regulate immune response to the antigen. Preferably, the antigen is an alloantigen. Such antigens can be selected from any known in the art. [0044] The cell populations useful in the methods of this invention comprise “apoptotic cells,” which include cells and cell bodies, i.e., apoptotic bodies, that exhibit, or will exhibit, one or more apoptosis-characterizing features. An apoptotic cell may: comprise any cell that is in the Induction phase, Effector phase, or the Degradation phase. The cell populations in the therapies of the invention may also comprise cells that have been treated with an apoptosis-inducing agent that are still viable. Such cells may exhibit apoptosis-characterizing features at some point, for example, after administration to the subject. Preferably, the ACs are autologous PBMCs that have been treated with an apoptosis inducer. Preferably the apoptosis inducer is ECP. [0045] ECP directly induces significant levels of apoptosis. This has been observed, for example, in lymphocytes of CTCL, GVHD, and scleroderma patients. The apoptotic cells contribute to the observed clinical effect. [0046] Apoptosis-characterizing features may include, but are not limited to, surface exposure of phosphatidylserine, as detected by standard, accepted methods of detection such as Annexin V staining; alterations in mitochondrial membrane permeability measured by standard, accepted methods evidence of DNA fragmentation such as the appearance of DNA laddering on agarose gel electrophoresis following extraction of DNA from the cells or by in situ labeling. Salvioli et al. (1997); Teiger et al. (1996); and Gavrieli et al. (1992). [0047] The cell population for use in the present invention is induced to become apoptotic ex vivo, i.e., extracorporeally, and is compatible with those of the subject, donor, or recipient. A cell population may be prepared from substantially any type of mammalian cell including cultured cell lines. For example, a cell population may be prepared from a cell type derived from the mammalian subject's own body autologous) or from an established cell line. Specifically, a cell population may be prepared from white blood cells of blood compatible with that of the mammalian subject, more specifically, from the subject's own white blood cell and even more specifically, from the subject's own leukocytes or T cells. [0048] A cell population may also be prepared from an established cell line. A cell line that may be useful in the methods of the present invention includes, for example, Jurkat cells (ATCC No. TIB-152). Other cells lines appropriate for use in accordance with the methods of the present invention may be identified and/or determined by those of ordinary skill in the art. The cell population may be prepared extracorporeally prior to administration to the subject, donor, or recipient. Thus, in one embodiment, an aliquot of the subject's blood, recipient's blood, or the donor's blood may be withdrawn, e.g. by venipuncture, and at least a portion of the white cells thereof subjected extracorporeally to apoptosis-inducing conditions. [0049] In one embodiment, the cell population may comprise a particular subset of cells including, but not limited to leukocytes or cells separated from leukocytes on the basis of their expression of CD4, that is CD4+ T cells. The separation and purification of blood components is well known to those of ordinary skill in the art. Indeed, the advent of blood component therapy has given rise to numerous systems designed for the collection of specific blood components. Several of these collection systems are commercially available from, for example, Immunicon Corp. (Huntingdon Valley, Pa.), Baxter International (Deerfield, Ill.), and Dynal Biotech (Oslo, Norway). [0050] Immunicon's separation system separates blood components using magnetic nanoparticles (ferrofluids) coated with antibodies that conjugate, i.e., form a complex, to the target components in a blood sample. The blood sample is then incubated in a strong magnetic field and the target complex migrates away from the rest of the sample where it can then be collected. See, e.g., U.S. Pat. Nos. 6,365,362; 6,361,749; 6,228,624; 6,136,182; 6,120,856; 6,013,532; 6,013,188; 5,993,665; 5,985,153; 5,876,593; 5,795,470; 5,741,714; 5,698,271; 5,660,990; 5,646,001; 5,622,831; 5,591,531; 5,541,072; 5,512,332; 5,466,574; 5,200,084; 5,186,827; 5,108,933; and 4,795,698. [0051] Dynal's Dynabeads® Biomagnetic separation system separates blood components using magnetic beads coated with antibodies that conjugate to the target components in a blood sample, forming a Dynabeads-target complex. The complex is then removed from the sample using a Magnetic Particle Concentrator (Dynal MPC®). Several different cell types may be collected using this separation system. T cells and T cell subsets can also be positively or negatively isolated or depleted from whole blood, buffy coat, gradient mononuclear cells or tissue digests using, for example, CELLection™ CD2Kit (Prod. No 116.03), Dynabeads® M-450 CD2 (Prod. No 111.01/02), Dynabeads®) CD3 (Prod. No 111.13/14), Dynabeads® plus DETACHaBEAD (Prod. No. 113.03), Dynabeads® M-450 CD4 (Prod. No 111.05/06), CD4 Negative Isolation Kit (T helper/inducer cells) (Prod. No. 113.17), CD8 Positive Isolation Kit (Prod. No. 113.05), Dynabeads® CD8 (Prod. No. 111.07/08), CD8 Negative Isolation Kit (Prod. No. 113.19), T Cell Negative Isolation Kit (Prod. No. 113.11), Dynabeads® CD25 (Prod. No 111 . 33 / 34 ), and Dynabeads® CD3/CD28 T Cell Expander (Prod. No. 111.31). Baxter International has developed several apheresis systems based on the properties of centrifugation, including the CS-3000 blood cell separator, the Amicus separator, and the Autopheresis-C system. The CS-3000 Plus blood cell separator collects both cellular apheresis, products and plasma. It comprises a continuous-flow separator with a dual-chamber centrifugal system that collects apheresis products. The Amicus operates in either a continuous-flow or intermittent-flow format to collect single donor platelets and plasma. The Autopheresis-C system is designed for the collection of plasma from donors and can collect more than 250 mL of plasma. See generally, U.S. Pat. Nos. 6,451,203; 6,442,397; 6,315,707; 6,284,142; 6,9'51,284; 6,033,561; 6,027,441; and 5,494,578. [0052] In the most preferred embodiment of the invention, ECP is used to induce apoptosis. This involves a photoactivatable compound added to a cell population ex vivo. The photosensitive compound may be administered to a cell population comprising blood cells following its withdrawal from the subject, recipient, or donor, as the case may be, and prior to or contemporaneously with exposure to ultraviolet light. The photosensitive compound may be administered to a cell population comprising whole blood or a fraction thereof provided that the target blood cells or blood components receive the photosensitive compound. In another embodiment, a portion of the subject's blood, recipient's blood, or the donor's blood could first be processed using known methods to substantially remove the erythrocytes and the photoactive compound may then be administered to the resulting cell population comprising the enriched PBMC fraction. [0053] Photoactivatable compounds for use in accordance with the present invention include, but are not limited to, compounds known as psoralens (or furocoumarins) as well as psoralen derivatives such as those described in, for example, U.S. Pat. No. 4,321,919; and U.S. Pat. No. 5,399,719. Preferred compounds include 8-methoxypsoralen; 4,5′8-trimethylpsoralen; 5-methoxypsoralen; 4-methylpsoralen; 4,4-dimethylpsoralen; 4,5′-dimethylpsoralen; 4′-aminomethyl-4,5′,8-trimethylpsoralen; 4′-hydroxymethyl-4,5′,8-trimethylpsoralen; 4′,8-methoxypsoralen; and a 4′-(omega-amino-2-oxa) alkyl-4,5′8-trimethylpsoralen, including but not limited to 4′-(4-amino-2-oxa)butyl-4,5′,8-trimethylpsoralen. In one embodiment, the photosensitive compound that may be used comprises the psoralen derivative, amotosalen(S-59) (Cerus Corp., Concord, Calif.). In another embodiment, the photosensitive compound comprises 8-methoxypsoralen (8 MOP). [0054] The cell population to which the photoactivatable compound has been added is treated with a light of a wavelength that activates the photoactivatable compound. The treatment step that activates the photoactivatable compound is preferably carried out using long wavelength ultraviolet light (UVA), for example, at a wavelength within the range of 320 to 400 nm. The exposure to ultraviolet light during the photopheresis treatment preferably is administered for a sufficient length of time to deliver about 1-2 J/cm 2 to the cell population. [0055] Extracorporeal photopheresis apparatus useful in the methods according to the invention include those manufactured by Therakos, Inc., (Exton, Pa.) under the name UVAR®. A description of such an apparatus is found in U.S. Pat. No. 4,683,889. The UVAR®system uses a treatment system and consists of three phases including: 1) the collection of a buffy-coat fraction (leukocyte-enriched), 2) irradiation of the collected buffy coat fraction, and 3) reinfusion of the treated white blood cells. The collection phase has six cycles of blood withdrawal, centrifugation, and reinfusion steps. During each cycle, whole blood is centrifuged and separated in a pheresis bowl. From this separation, plasma (volume in each cycle is determined by the UVAR® instrument operator) and 40 ml buffy coat are saved in each collection cycle. The red cells and all additional plasma are reinfused to the patient before beginning the next collection cycle. Finally, a total of 240 ml of buffy coat and 300 ml of plasma are separated and saved for UVA irradiation. [0056] The irradiation of the leukocyte-enriched blood within the irradiation circuit begins during the buffy coat collection of the first collection cycle. The collected plasma and buffy coat are mixed with 200 ml of heparinized normal saline and 200 mg of UVADEX® (water soluble 8-methoxypsoralin). This mixture flows in a 1.4 mm thick layer through the PHOTOCEPTOR® Photoactivation Chamber, which is inserted between two banks of UVA lamps of the PHOTOSETTE®. PHOTOSETTE® UVA lamps irradiate both sides of this UVA-transparent PHOTOCEPTOR® chamber, permitting a 180-minute exposure to ultraviolet A light, yielding an average exposure per lymphocyte of 1-2 J/cm 2 . The final buffy coat preparation contains an estimated 20% to 25% of the total PBMC component and has a hematocrit from 2.5% to 7%. Following the photoactivation period, the volume is reinfused to the patient over a 30 to 45 minute period. U.S. patent application Ser. No. 09/480,893 describes another system for use in ECP administration. U.S. Pat. No. 5,951,509; 5,985,914; 5,984,887, 4,464,166; 4,428,744; 4,398,906; 4,321,919; WO 97/36634; and WO 97/36581 also contain description of devices and methods useful in this regard. [0057] Another system that may be useful in the methods of the present invention is described in U.S. patent application Ser. No. 09/556,832. That system includes an apparatus by which the net fluid volume collected or removed from a subject may be reduced during ECP. The effective amount of light energy that is delivered to a cell population may be determined using the methods and systems described in U.S. Pat. No. 6,219,584. [0058] A variety of other methods for inducing apoptosis in a cell population are well-known and may be adopted for use in the present invention. One such treatment comprises subjecting a cell population to ionizing radiation (gamma-rays, x-rays, etc.) and/or non-ionizing electromagnetic radiation including ultraviolet light, heating, cooling, serum deprivation, growth factor deprivation, acidifying, diluting, alkalizing, ionic strength change, serum deprivation, irradiating, or a combination thereof. Alternatively, apoptosis may be induced by subjecting a cell population to ultrasound. [0059] Yet another method of inducing apoptosis comprises the extracorporeal application of oxidative stress to a cell population. This may be achieved by treating the cell population, in suspension, with chemical oxidizing agents such as hydrogen peroxide, other peroxides and hydroperoxides, ozone, permanganates, periodates, and the like. Biologically acceptable oxidizing agents may be used to reduce potential problems associated with residues and contaminations of the apoptosis-induced cell population so formed. [0060] In preparing the apoptosis-induced cell population, care should be taken not to apply excessive levels of oxidative stress, radiation, drug treatment, etc., because otherwise there may be a significant risk of causing necrosis of at least some of the cells under treatment. Necrosis causes cell membrane rupture and the release of cellular contents often with biologically harmful results, particularly inflammatory events, so that the presence of necrotic cells and their components along with the cell population comprising apoptotic cells is best avoided. Appropriate levels of treatment of the cell population to induce, apoptosis, and the type of treatment chosen to induce apoptosis are readily determinable by those skilled in the art. [0061] One process according to the present, invention involves the culture of cells from the subject, or a compatible mammalian cell line. The cultured cells may then be treated extracorporeally to induce apoptosis and to create a cell population therein. The extracorporeal treatment may be selected from the group consisting of antibodies, chemotherapeutic agents, radiation, ECP, ultrasound, proteins, and oxidizing agents. The cells, suspended in the subject's plasma or another suitable suspension medium, such as saline or a balanced mammalian cell culture medium, may then be incubated as indicated below. [0062] Methods for the detection and quantitation of apoptosis are useful for determining the presence and level of apoptosis in the preparation to be incubated with leukocytes or T cells in the present invention. In one embodiment, cells undergoing apoptosis may be identified by a characteristic ‘laddering’ of DNA seen on agarose gel electrophoresis, resulting from cleavage of DNA into a series of fragments. In another embodiment, the surface expression of phosphatidylserine on cells may be used to identify and/or quantify an apoptosis-induced cell population. Measurement of changes in mitochondrial membrane potential, reflecting changes in mitochondrial membrane permeability, is another recognized method of identification of a cell population. A number of other methods of identification of cells undergoing apoptosis and of a cell population, many using monoclonal antibodies against specific markers for a cell population, have also been described in the scientific literature. [0063] The administration of T regs finds utility in treating arthritis and other autoimmune diseases. They are also useful in the treatment or prophylaxis of at least one autoimmune-related disease in a cell, tissue, organ, animal, or patient including, but not limited to, acute transverse myelitis, alopecia areata, Alzheimer's disease, amyotrophic lateral sclerosis, ankylosing spondylitis, antiphospholipid syndrome atherosclerosis, autoimmune Addison's disease, autoimmune hemolytic anemia, Behcet's disease, bullous pemphigoid, cardiomyopathy, celiac sprue-dermatitis, Cerebellar Spinocerebellar Disorders, spinocerebellar degenerations (spinal ataxia, Friedreich's ataxia, cerebellar cortical degenerations), chronic alcoholism, alcohol-induced hepatitis, autoimmune hepatitis, chronic fatigue immune dysfunction syndrome (CFIDS), chronic inflammatory bowel disease, chronic inflammatory demyelinating polyneuropathy, Churg-Strauss syndrome, cicatricial pemphigoid, cold agglutinin disease, CResT syndrome, Creutzfeldt-Jakob disease, Crohn's disease, Dejerine-Thomas, Dementia pugilistica, diabetes mellitus, Diffuse Lewy body disease, discoid lupus, disorders of the basal ganglia, disseminated intravascular coagulation, Down's Syndrome in middle age, drug-induced movement disorders, essential mixed Cryoglobulinemia, fibromyalgia-fibromyositis, graft versus host disease, Graves' disease, Guillain-Barré, Hallerrorden-Spatz disease, Hashimoto's thyroiditis, Huntington's Chorea senile chorea, idiopathic pulmonary fibrosis, idiopathic thrombocytopenia purpura (ITP), IgA nephropathy, infantile or juvenile spinal muscular atrophy, insulin dependent diabetes, juvenile arthritis, Kawasaki's pathology, lesions of the corticospinal system, Leukemias, Hodgkin's lymphoma, non-Hodgkin's lymphoma, lichen planus, Méńíère's disease, mixed connective tissue disease, multiple sclerosis, multiple systems degenerations (Mencel, Dejerine-Thomas, Shy-Drager, Machado-Joseph), myasthenia gravis, neurogenic muscular, Parkinson's disease, pemphigus vulgaris, pernicious anemia, polyarteritis nodosa, polychondritis, polyglandular syndromes, polymyalgia rheumatica, polymyositis dermatomyositis, primary agammaglobulinemia, primary biliary cirrhosis, Progressive supranuclear palsy, psoriasis, Raynaud's phenomenon, Reiter's syndrome, rheumatic fever, rheumatoid arthritis, sarcoidosis, scleroderma, Senile Dementia of Lewy body type, Sjögren's syndrome, stiff-man syndrome, Subacute sclerosing panencephalitis, systemic disorders (Refsum's disease, abetalipoprotemia, ataxia, telangiectasia, mitochondrial multi-system disorder), systemic lupus erythematosus (SLE), Takayasu arteritis, temporal arteritis/giant cell arteritis, thyroidosis, ulcerative colitis, uveitis, vasculitis, vitiligo, Wegener's granulomatosis, Wernicke-Korsakoff syndrome. [0064] The present invention is also useful in treating graft rejection or graft versus host disease (GVHD). Acute solid organ transplantation rejection occurs in 30% to 60% of patients after lung transplantation and to a lower degree with liver, kidney, heart etc. due to the success of immunosuppressive agents. The lymphocyte (cell)-mediated immune reaction against transplantation antigens is the principal mechanism of acute rejection. A delayed or chronic rejection causes graft destruction in months to years after transplantation and is characterized by vascular destruction leading to necrosis of the transplanted tissue. This rejection is not currently suppressed to any large degree by standard regimens and thus the need for more sustainable immune tolerance is a significant unmet need. [0065] Late graft deterioration occurs occasionally, and this chronic type of rejection often progresses insidiously despite increased immunosuppressive therapy. The pathologic picture differs from that of acute rejection. The arterial endothelium is primarily involved, with extensive proliferation that may gradually occlude the vessel lumen, resulting in ischemia and fibrosis of the graft. [0066] Immunosuppressants are currently widely used to control the rejection reaction and are primarily responsible for the success of transplantation. However, these drugs suppress all immunologic reactions, thus making overwhelming infection the leading cause of death in transplant recipients. [0067] Existing immunosuppressant treatment can differ in the case of different types of transplants. Liver allografts are less aggressively rejected than other organ allografts. For example, hyperacute rejection of a liver transplant does not occur invariably in patients who were presensitized to HLA antigens or ABO incompatibilities. Typical immunosuppressive therapy in an adult involves using cyclosporine, usually given IV at 4 to 6 mg/kg/day starting at the time of transplantation and then 8 to 14 mg/kg/day po when feeding is tolerated. Doses are adjusted, downward if renal dysfunction occurs, and blood levels are used as approximate measures of adequate dosage. [0068] In heart transplantation, immunosuppressive regimens are similar to those for kidney or liver transplantation. However, in lung and heart-lung transplants acute rejection occurs in >80% of patients but may be successfully managed. Patients are treated with corticosteroids, given rapidly IV in high dosage, ATG, or OKT3. Prophylactic ALG or OKT3 is also frequently given during the first two post-transplant weeks. Pancreas transplantation is unique among the vascularized organ transplants: instead of being used to save a life, it attempts to stabilize or prevent the devastating target organ complications of type I diabetes. Because the recipient exchanges the risks of insulin injection with the risks of immunosuppression, pancreas transplantation has been generally limited primarily to patients who already need to receive immunosuppressive drugs (i.e., diabetics with renal failure who are receiving a kidney transplant). [0069] Patients with acute myeloid or lymphoblastic leukemia may benefit from bone marrow transplant (BMT). Pediatric BMT has expanded because of its potential for curing children with genetic diseases (e.g., thalassemia, sickle cell anemia, immunodeficiencies, inborn errors of metabolism). Another option for BMT is autologous transplantation (removal of a patient's own marrow when a complete remission has been induced, followed by ablative treatment of the patient with the hope of destruction of any residual tumor and rescue with the patient's own bone marrow). Since an autograft is used, no immunosuppression is necessary other than the short-term high-dose chemotherapy used for tumor eradication and bone marrow ablation; posttransplant problems with GVHD are minimal. [0070] The rejection rate is <5% in transplants for leukemia patients from HLA-identical donors. For multiply transfused patients with aplastic anemia, the rejection rate has also been significantly decreased because of increased immunosuppression during transplant induction. Nonetheless, complications can arise including rejection by the host of the marrow graft, acute GVHD, and infections. Later complications include chronic GVHD, prolonged imnmunodeficiency, and disease recurrence. [0071] Numerous other transplantations can be made more effective with the treatment of the present invention. Examples include, corneal transplantation, skin allografts, cartilage allografts, bone grafts, and small bowel transplants. [0072] A host of other disorders can be treated more effectively using the methods of the present invention. For example, cutaneous T cell lymphoma is a disease in which T lymphocytes become malignant and affect the skin. Three kinds of treatment are commonly used: radiation; chemotherapy; and photopheresis. Treatment of cutaneous T cell lymphoma depends on the stage of the disease, and the patient's age and overall health. Standard treatment may be considered because of its effectiveness in patients in past studies, or participation in a clinical trial may be considered. Most patients with cutaneous T cell lymphoma are not cured with standard therapy and some standard treatments may have more side effects than are desired. Treatment using the method of the present invention can be used in the treatment of this disease as well. [0073] The methods of the present invention may also be used in implant surgery, for example, with implant surgery commonly performed in cosmetic or non-cosmetic plastic surgery. Such implants may include dental, fat grafting, for example to the cheeks, lips and buttocks, facial implants, including those to the nose, cheeks, forehead, chin and skull, buttocks implants, breast implants, etc. Other implants include, but are not limited to, corneal ring, cortical, orbital, cochlear, muscle (all muscles, including pectoral, gluteal, abdominal, gastrocnemius, soleus, bicep, tricep), alloplastic joint and bone replacement, bone repair implants (screws, rods, beams, bars, springs), metal plates, spinal, vertebral hair; botox/collagen/restylane/perlane injections, penile implants, prostate seed implants, breast implants (cosmetic and reconstructive), intrauterine devices, hormonal implants; fetal or stem cell implantation, pacemaker, defibrillator, artificial arteries/veins/valves, and artificial organs. [0074] Autoimmune diseases can also be more effectively treated using the methods of the present invention. These are diseases in which the immune system produces autoantibodies to an endogenous antigen, with consequent injury to tissues. Individuals may be identified as having a disease by several methods, including, but not limited to, HLA linkage typing, blood or serum-based assays, or identification of genetic variants, e.g., single nucleotide polymorphisms (SNPs). For example, once an individual is determined to have the HLA DR4 linkage and has been diagnosed to have rheumatoid arthritis, T reg treatment can be prescribed. Other HLA alleles, also known as MHC alleles, that are associated with autoimmune diseases include B27 (Ankylosing spondylitis); DQA1*0501 and DQB1*0201 (Celiac disease); DRB1*03, DRB1*04, DQB1*0201, DQB1*0302, and DMA*0101 (Type I Diabetes); and Cw6 (Psoriasis). These alleles may also be used to determine whether an individual is experiencing an autoimmune disease and, thus, whether T reg treatment may be efficacious. [0075] Blood- or serum-based assays may be used to assess predisposition to a disease. There is, for example, an assay that detects the presence of autonuclear antibodies in serum, which may lead to the onset of lupus. Serum-based assays also exist for predicting autoimmune myocarditis. In addition, serum-based assays may be used to determine insulin levels (diabetes) or liver or heart enzymes for other diseases. T3 levels may be predictive of Hashimotos thyroiditis. After an individual is determined to be having a disease using a blood or serum-based assay, the, methods of the present invention may be used to prevent, or delay the onset of, or reduce the effects of these diseases. Individuals may be identified as being predisposed for disease through the identification of genetic variations, including, but not limited to, SNPs. Thus, in a further aspect of the invention, a determination is first made that a patient has an autoimmune disorder or is predisposed to one and that patient is then prescribed treatment with T regs. [0076] The methods of this invention are also applicable to the treatment of atopic diseases, which are allergic diseases in which individuals are very sensitive to extrinsic allergens. Atopic diseases include, but are not limited to, atopic dermatitis, extrinsic bronchial asthma, urticaria, allergic rhinitis, allergic enterogastritis and the like. Standard diagnostic tests can be used to determine whether a patient has a disorder of the type described above. [0077] The following examples are provided to illustrate but not limit the claimed invention. All references cited herein are hereby incorporated herein by reference. Example 1 Apoptotic Induction Via 8MOP/UVA [0078] Normal donor human leukocytes were passed over Ficoll-paque and PBMC collected and washed before placing at approximately 10 7 cells/ml in a T-75 tissue culture flask; To this flask 200 ng/ml 8-MOP was added before UVA irradiation (˜3 J/cm 2 ). Cells were quickly removed from the flask, in order to avoid adherence, and placed at the appropriate concentration for Treg generation. Treg Generation [0079] Normal donor human leukocytes were passed over Ficoll-paque and PBMC were collected. T lymphocytes were purified from PBMCs using magnetically activated cell sorter columns and CD4 + negative selection antibody cocktail (Miltenyi Biotec). The purified naive CD4 T cells were co-incubated with ECP-treated PBMCs at a 2:1 ratio (CD4:PBMCs) with 20 ng/ml IL-10 for 8 days ( FIG. 1A ). After 8 days, the CD4 + T cells were purified using MACs and CD4 positive selection antibody cocktail (Miltenyi Biotec). IL-10 is not required but, in some instances, induces a more consistent phenotype. Treg Evaluation [0080] Treg suppressive activity was evaluated by a secondary mixed lymphocyte reaction (“MLR”) ( FIG. 1B ). Syngeneic CD4 + T cells were placed in a 96 well plate at 10,000, cells/well. Allogeneic dendritic cells were added to the well at 2000 cells per well. The Tregs were titrated into the MLR starting at a ratio of 1 Treg cell to 4 responder T cells. Proliferation was measured on day 5 by bromodeoxyuridine (“BRDU”) incorporation using Roche's Cell Proliferation BRDU chemiluminescent ELISA. Chemiluminescence was measured using TopCount (Perkin Elmer). Example 2 T Reg Activity Is Found In Generation Of T cells By The Present Method [0081] CD4+ T cells were incubated with ECP treated peripheral blood cells for 8 days in the presence of 20 ng/mL IL-10. T regs were purified from the culture using MACs and CD4 positive selection antibody cocktail (Miltenyi Biotec). To assess their regulatory activity, the T regs were then added into an ML consisting of 10,000 syngeneic CD4+ T cells and 2000 allogeneic dendritic cells. Proliferation in these cultures was measured on day 5 by BRDU incorporation. The results are shown in FIG. 2 . Example 3 T Reg Activity Is Found In Generation Of T cells By The Present Method [0082] Tr1 cells were generated by incubating CD4+ T cells in the presence of 20 ng/ml IL-10. T regs were generated by incubating CD4+ T cells with ECP treated peripheral blood cells for 8 days in the presence of 20 ng/ml IL-10. T regs were purified from the culture using MACs and CD4 positive selection antibody cocktail (Miltenyi Biotec). To assess their regulatory activity, the T regs were then added into an MLR consisting of 10,000 syngeneic CD4+ T cells and 2000 allogeneic dendritic cells. Proliferation in these cultures was measured on day 5 by BRDU incorporation. The results are shown in FIG. 3 . Example 4 T Reg Phenotype Is Found In Generation Of T Cells With The Present Method [0083] CD4 +T cells were incubated with ECP treated peripheral blood cells for 8 days in the presence of 20 ng/mL IL-10. T regs were purified from the culture using MACs and CD4 positive selection antibody cocktail (Miltenyi Biotec). The T regs were then added to an MLR consisting of 10,000 syngeneic CD4 +T cells and 2000 allogeneic dendritic cells. IL-2 was added to the MLR at 2 ng/ml. Proliferation in these cultures was measured on day 5 by BRDU incorporation. The results are shown in FIG. 4 . Example 5 T Reg Phenotype Is Found In Generation Of T Cells With The Present Method [0084] Tregs generated by co-incubation with ECP-treated PBMCs were evaluated in a MLR using a 24-well transwell insert system (Nunc Tissue Culture 0.2 μM Anopore Insert system #136935). A MLR consisting of 500,000 syngeneic CD4+ T cells and 100,000 allogeneic dendritic cells were placed in the bottom portion of the transwell. 250,000 Tregs were placed in either the transwell insert or directly into the bottom well with the responder T cells and allogeneic dendritic cells. On day 5, the inserts were removed and proliferation was measured on day 5 by BRDU incorporation. The results are shown in FIG. 5 . Example 6 Mouse Model In Vivo Application) (Prophetic) Mice [0085] Male C3H/HeJ (C3H; H2k), (B6XC3H)F1 (H2bXk), (B6XDBA/2)F1 (H2bXd), C57BU6 (B6; H2b), and CBA/JCr (CBA; H2k) mice will be purchased from the National Cancer Institute Research and Development Center (Frederick, Md.). B10.BR (H2k) mice will be purchased from the Jackson Laboratories (Bar Harbour, Me.). Mice used for experiments will be between 6-10 weeks of age, and housed in sterile microisolator cages within a specific pathogen-free facility, receiving autoclaved food and water ad libitum. Media [0086] Phosphate-buffered saline (PBS) supplemented with 0.1% bovine serum albumin (BSA; Sigma Chemical Co., St Louis, Mo.) will be used for all in vitro manipulations of the donor bone marrow and lymphocytes. Immediately prior to injection, the cells will be washed and resuspended in PBS alone. For maintaining cell lines and for in vitro assays, RPMI 1640 medium (Mediatech, Herndon, Va.) will be used, supplemented with 10% fetal bovine serum (FBS; GIBCO, Grand Island, N.Y.), 2 mmol/L L-glutamine, 50 IU/mL penicillin, and 50 μg/mL streptomycin. [0087] Antibodies Experimental Photopheresis [0088] Splenocytes will be harvested from syngeneic littermate healthy mice and made into single cell suspension by grinding with the back end of a syringe in PBS. These cells will be re-suspended and cells washed twice with PBS before re-suspending at 12.5×10 6 cells/mL PBS. Upon washing cells they will be resuspended in ice-cold medium and seeded at approximately 106 cells/ml in a T75 flask. Psoralen (UVADEX solution) will be added to a final concentration of 200 ng/ml, which is a 100 fold dilution from the stock solution provided by Therakos. The flask will be placed lying down in the UVA irradiation chamber and given approximately 1.5 J/cm 2 of light which corresponds to 1.5 minutes of bottom light when the tray is 6 cm from the light, source. Cells will be quickly removed from the flask to avoid adherence and placed at the appropriate concentration for injection. If there is adherence, the flask will be gently scraped or tapped to remove most of the cells. Bone Marrow Transplantation [0089] Bone marrow will be harvested from the tibia and femurs of donor mice by flushing with PBS containing 0.01% BSA (PBS/BSA). Bone marrow cells will be depleted of T cells using an anti-Thy 1.2 nAb (J1j; American Type Culture Collection, Rockville, Md.) at a 1:100 dilution and guinea pig complement (Rockland Immunochemicals, Gilbertsville, Pa.) at a dilution of 1:6 for 45 minutes at 37° C. Lymphocytes will be isolated from spleens and lymph nodes of donor mice. Splenocytes will be treated with Gey's balanced salt lysing solution containing 0.7% ammonium chloride (NH 4 Cl) to remove red blood cells (RBCs). After RBC depletion, spleen and lymph node cells will be pooled and depleted of B cells by panning on a plastic Petri dish, precoated with a 5 mg/ml dilution of goat anti-mouse IgG for 1 hour at 4° C. These treatments are expected to result in donor populations of approximately 90%-95% CD3+ cells, as quantitated by fluorescent flow cytometry. T cells subsets will be then isolated via negative selection using either anti-CD8 (3.168) or anti-CD4 mAb (RL172) and complement. These treatments are expected to reduce the targeted T cell subset populations to background levels, as determined by flow cytometric analysis. Recipient mice will be exposed to 13 Gy whole body irradiation from a 137CS source at 1.43 Gy/min, delivered in a split dose of 6.5 Gy each, separated by 3 hours. These mice will be then be transplanted with 2×10 6 anti-Thy 1.2 treated bone marrow cells (ATBM; T cell-depleted) along with the indicated number of appropriate cells (donor CD4 or CD8 enriched T cells), intravenously (i.v.) via the tail vein. Mice will be treated with T regs 1 day before transplantation and again on days 0, 4, 8, and 12 (all at 0.5 mg; i.p.). For GVL experiments, B6 recipient mice will be challenged with an injection of T regs one day before transplantation of donor ATBM and T cells, with a similar schedule of T reg treatment. In both GVHD and GVL experiments, the mice will be checked daily for morbidity and mortality until completion. The data will be pooled firm 2-3 separate experiments, and median survival times (MST) will be determined as the interpolated 50% survival point of a linear regression through all of the day of death data points, including zero. Statistical comparisons for survival between experimental groups will be performed by the nonparametric Wilcoxon signed rank test. Significance for weight comparisons will be determined by the T-test at individual time points. Flow Cytometry [0090] Appropriate pbs in volumes of 25 μL will be incubated with 2-5×10 5 cells in the wells of a 96-well U-bottom microplate at 4° C. for 30 minutes, centrifuged at 1500 rpm for 3 minutes, and washed with PBS containing 0.1% BSA and 0.01% sodium azide (wash buffer). The percentage positive cells, and the arithmetic mean fluorescence intensity will be calculated for each sample. Pathological Analysis [0091] Full thickness ear biopsies (3×2 mm) will be sampled from each mouse of the various treatment groups and immediately fixed in 4% glutaraldehyde overnight and then rinsed with 0.1 M sodium cacodylate buffer (pH 7.4). Tissues will be post-fixed with 2% osmium tetroxide for 2 h, dehydrated in graded ethanol and embedded in Epon 812. One-micron-thick sections will be cut with a Porter-Blum MT2B ultramicrotome, stained with toluidine blue, and finally dipped in 95% ethanol for light microscopic analysis. The number of dyskeratotic epidermal cells/linear mm, as previously determined, will be counted under a ×100 objective and a ×10 eye piece of a light microscope. More than ten linear mm of the epidermis will be assessed in each animal and each time point. The analysis will be performed under blinded conditions as to the treatment groups. [0092] Additional animal models for T regs are provided for instance by 20030157073; Kohm, A et al. (2002); Tang, Q et al. 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Many cell types in the body can remove apoptotic and cellular debris from tissues; however, the professional phagocyte, or antigen presenting cell (“APC”), has a high capacity to do so. The recognition of apoptotic cells (“ACs”) occurs via a series of evolutionarily-conserved, AC associated molecular-pattern receptors (“ACAMPRs”) on APCs that recognize and bind corresponding apoptotic-cell-associated molecular patterns (“ACAMPs”). These receptors recognize ligands such as phosphotidyl serine and oxidized lipids found on apoptotic cells. Savill et al. (2002); and Gregory et al. (2004).

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to foreign Patent Application FR 09 02993, filed on Jun. 19, 2009, the disclosure of which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION [0002] The field of the invention is that of passive surface acoustic wave sensors, also known as “SAW” sensors, making it possible to perform for example measurements of temperature and/or of pressure/stresses remotely, and more precisely that of the collective fabrication of such sensors. BACKGROUND OF THE INVENTION [0003] One type of temperature sensor can typically consist of two SAW resonators denoted R 1 and R 2 and undertake differential measurements. For this purpose the two resonators are designed to have different resonant frequencies. [0004] Typically, each resonator is composed of a transducer with inter-digitated combs, consisting of an alternation of electrodes, which are repeated with a certain periodicity called the metallization period, deposited on a piezoelectric substrate that may advantageously be quartz. The electrodes, advantageously aluminium or aluminium alloy (produced by a photolithography method), exhibit a low thickness relative to the metallization period (typically, a few hundred nanometres to a few micrometers). For example for a sensor operating at 433 MHz, the metal (aluminium for example) thickness used can be of the order of 100 to 300 nanometres, the metallization period and the electrode width possibly being respectively of the order of 3.5 μm and 2.5 μm. [0005] One of the ports of the transducer is for example linked to the live point of a Radio Frequency (RF) antenna and the other to earth or else the two ports are linked to the antenna if the latter is symmetric (dipole for example). The field lines thus created between two electrodes of different polarities give rise to surface acoustic waves in the zone of overlap of the electrodes. [0006] The transducer is a bi-directional structure, that is to say the energy radiated towards the right and the energy radiated towards the left have the same intensity. By arranging electrodes on either side of the transducer, the said electrodes playing the role of reflector, a resonator is produced, each reflector partially reflecting the energy emitted by the transducer. [0007] If the number of reflectors is multiplied, a resonant cavity is created, characterized by a certain resonant frequency. This frequency depends firstly on the speed of propagation of the waves under the network, the said speed depending mainly on the physical state of the substrate, and therefore sensitive for example to temperature. In this case, this is the parameter which is measured by the interrogation system and it is on the basis of this measurement that a temperature can be calculated. [0008] It is recalled that the variation of the resonant frequency as a function of temperature of a quartz resonator is determined by the following formula: [0000] f ( T )= f 0 [1 +CTF 1 ( T−T 0 )+ CTF 2 ( T−T 0 ) 2 ] With f 0 the frequency at T 0 , T 0 being the reference temperature (25° C. by convention), CTF 1 the first-order coefficient (ppm/° C.) and CTF 2 the second-order coefficient (ppb/° C. 2 ). [0010] The two resonators can use different wave propagation directions, produced though an inclination of the different inter-digitated electrode combs on one and the same substrate, for example quartz. [0011] The two resonators can also advantageously use different quartz cuts making it possible to endow them with different resonant frequencies, in this instance for the resonator R 1 the quartz cut (YX1)/θ 1 and for the resonator R 2 : the cut (YX1)/θ 2 with reference to the IEEE standard explained hereinafter, the two resonators using propagation which is collinear with the crystallographic axis X. [0012] Whatever solution is adopted for creating different resonant frequencies, the fact of using a differential structure presents several advantages. The first is that the frequency difference of the resonators is almost linear as a function of temperature and the residual non-linearities taken into account by the calibration of the sensor. Another advantage of the differential structure resides in the fact that it is possible to sidestep the major part of the ageing effects. [0013] It is recalled that the expression “calibration operation” denotes the determination of so-called calibration parameters A 0 , A 1 and A 2 of the following function: [0000] T=A 0 ±√{square root over ( A 1 +A 2 Δf )} [0014] When these parameters are defined, a differential measurement of frequency then makes it possible to determine a temperature. [0015] Generally, resonators are produced collectively on wafers 100 mm in diameter, typically this might involve fabricating about 1000 specimens on one and the same wafer. This therefore gives 1000 specimens of resonators R 1 and 1000 specimens of resonators R 2 , each temperature sensor comprising a pair of resonators R 1 and R 2 . [0016] The calibration operation is nonetheless expensive in terms of time since it makes it necessary to measure for each sensor the frequency difference between the two resonators at three different temperatures at the minimum and moreover requires the serialization of each sensor (corresponding to the identification of a sensor—calibration coefficients pair for each sensor). [0017] It is for example possible to envisage storing the calibration coefficients A 0 , A 1 , A 2 in the interrogation system. This configuration requires, in the event of a change of sensor, that the new coefficients be stored in the interrogation system. [0018] One of the aims sought in the present invention is to produce a calibration-free temperature sensor while retaining good precision in the temperature measurement. [0019] For this purpose it is necessary to control on the one hand the dispersion in the difference in resonant frequencies of the resonators R 1 and R 2 , and on the other hand the dispersion in the coefficients CTF 1 and CTF 2 (first-order and second-order temperature coefficients), or at least the difference in these coefficients CTF 1 and CTF 2 when a differential measurement is carried out, as is demonstrated hereinafter and by virtue of the following various reminders: [0020] 1) Concerning Crystalline Orientation [0021] In order to define the crystalline orientations, the IEEE standard is used. This designation uses the following 2 reference frames: the crystallographic reference frame (X, Y, Z). the working reference frame (w, l, t) defined by the surface of the substrate (normal to {right arrow over (t)}) and the direction of propagation of the surface waves (axis {right arrow over (l)}). [0024] The designation of a cut is of the type (YX wlt)/φ/θ/ψ with: YX two crystalline axes making it possible to place the working reference frame with respect to the crystallographic reference frame before any rotation. The first axis is along the axis t, normal to the surface whereas the second is along the axis l. The third axis of the working reference frame w is given by the sense of the right-handed trihedron (w, l, t). w, l, t indicates a series of axes around which it is possible to perform successive rotations by respective angles φ, θ, ψ. In the subsequent description, the variables φ, θ, ψ are associated with rotations around the respective axes w, l, t. [0027] 2) Concerning the Geometry of the Saw Resonator: [0028] The dimensions characterizing a surface wave device consisting of inter-digitated electrode combs Ei, which are symmetric with respect to an axis Ac and deposited on the surface of a piezoelectric substrate are denoted in the following manner and illustrated in FIG. 1 : [0029] the metallization period denoted: “p”; [0030] the wavelength denoted: “λ”, with λ=2·p; [0031] the electrode width denoted: “a”; [0032] the metallization thickness denoted “h”. [0033] In general, to sidestep the operating frequency of the device, the following normalized variables are actually used: the metallization ratio a/p, ratio of electrode width to the metallization period; the normalized metallization thickness h/λ ratio of the metallization thickness to the wavelength λ=2·p. [0036] 3) Concerning the Laws of Variations with Temperature of 2 Surface Wave Resonators: [0037] As defined previously it is possible to express the frequency behaviours of the two resonators respectively by the following equations: [0000] For the resonator R 1 : f 1 ( T )= f 01 ·(1 +C 11 ·( T−T 0 )+ C 21 ·( T−T 0 ) 2 )  (1) [0038] With: f 1 (T) the resonant frequency of R 1 as a function of temperature [0039] f 01 the resonant frequency of R 1 at the temperature T 0 (generally 25° C.); [0040] C 11 the 1 st -order temperature coefficient (generally called CTF1) of R 1 ; [0041] C 21 the 2 nd -order temperature coefficient (generally called CTF2) of R 1 ; [0000] For the resonator R 2 : f 2 ( T )= f 02 ·(1 +C 12 ·( T−T 0 )+ C 22 ·( T−T 0 ) 2 )  (2) [0042] With: f 2 (T) the resonant frequency of R 2 as a function of temperature [0043] f 02 the resonant frequency of R 2 at the temperature T 0 (generally 25° C.); [0044] C 12 the 1 st -order temperature coefficient (generally called CTF1) of R 2 ; [0045] C 22 the 2 nd -order temperature coefficient (generally called CTF2) of R 2 ; [0046] In the general case, the resonant frequency at 25° C. and the 1 st -order and 2 nd -order temperature coefficients depend mainly: [0047] on the chosen crystalline orientation; [0048] on the metallization period of “p” for f 0 alone; [0049] on the normalized metallization thickness h/λ; [0050] on the metallization ratio a/p. [0051] And generally, the frequency difference is a function of temperature which can therefore be expressed in the following manner: [0000] Δ   f  ( T ) =  f 2  ( T ) - f 1  ( T ) =  f 02 - f 01 + ( C 12 · f 02 - C 11 · f 01 ) · ( T - T 0 ) +  ( C 22 · f 02 - C 21 · f 01 ) · ( T - T 0 ) 2 =  Δ 0 + s · ( T - T 0 ) + ɛ · ( T - T 0 ) 2 ( 3 ) [0052] With: Δ 0 =f 02 −f 01 the difference in resonant frequency at the temperature T 0 ; [0053] s=C 12 ·f 02 −C 11 ·f 01 the 1 st -order differential coefficient [0054] ε=C 22 ·f 02 −C 21 ·f 01 the 2 nd -order differential coefficient [0055] The calibration coefficients make it possible on the basis of a measurement of the frequency difference to get back to the temperature information. It can be shown that: [0000] T = T 0 + - s ± s 2 - 4  ɛ  ( Δ 0 - Δ   f ) 2  ɛ = A 0 ± A 1 + A 2  Δ   f ( 4 ) [0056] Where A 0 , A 1 and A 2 are the calibration coefficients as explained in the preamble of the present description. [0057] 4) Concerning Manufacturing Dispersions: [0058] The methods of fabrication of resonators being controlled with a certain precision, the crystalline orientation (φ, θ, ψ) and the geometry of the resonator (related to the parameters a and h alone, in effect it is considered that the metallization period p is perfectly controlled) are never, in practice, exactly those aimed at and moreover they are not perfectly reproducible. [0059] For a sufficiently large sample, these parameters follow Gaussian distributions (law of large numbers) whose means and standard deviations can be determined experimentally. The whole set of variations of the five parameters φ, θ, ψ, a and h is called manufacturing dispersions. [0060] The parameters f 0 , C 11 , C 12 and C 21 , C 22 being dependent on φ, θ, ψ, a and h, can also be controlled with a certain precision and can follow distributions centred around a mean with a certain standard deviation. [0061] The applicant has started from the assumption that there were three predominant parameters in terms of manufacturing dispersions with respect to the set of five parameters f 0 , C 11 , C 12 and C 21 , C 22 . [0062] The three predominant parameters in the manufacturing dispersions are the following: the dispersion in the angle of cut θ which corresponds in IEEE notation to the cut (YX1)/θ; the dispersion in the metallization thickness a; the dispersion in the electrode width h. [0066] Indeed, the cuts of the substrates are chosen such that they comply with the criteria: φ=0 and ψ=0 thereby corresponding to the crystalline orientation (YXwlt)/φ=0/ψ=0 in IEEE notation. [0067] Now, the points φ=0 and ψ=0 correspond to points at which all the derivatives with respect to φ and ψ vanish. The variations of the following parameters taken into account (f 0 , C 1 , C 2 ) can be considered zero around these points: [0000] ∂ f 0 ∂ ϕ  ϕ = 0 = 0   ∂ C 1 ∂ ϕ  ϕ = 0 = 0   ∂ C 2 ∂ ϕ  ϕ = 0 = 0   ∂ f 0 ∂ ψ  ψ = 0 = 0   ∂ C 1 ∂ ψ  ψ = 0 = 0   ∂ C 2 ∂ ψ  ψ = 0 = 0 ( 5 ) [0068] Typically and by way of example, the following dispersions in these 3 parameters can be considered: [0069] a dispersion in electrode width: Δa=+/−0.06 μm; [0070] a dispersion in metallization thickness: Δh=+/−30 Angströms; [0071] a dispersion in angle of cut: Δθ=+/−0.05°. [0072] Assuming the 3 parameters follow Gaussian distributions, +/−3 times the standard deviation of the relevant parameter is called the dispersion: [0073] Δa=+/−3·σ(a) [0074] Δh=+/−3·σ(h) [0075] Δθ=+/−3·σ(θ) [0076] With σ(a), σ(h), σ(θ) respectively the standard deviations of the electrode width a, of the metallization thickness h and of the angle of cut θ. [0077] Note that for a Gaussian distribution with mean μ and standard deviation a, 99.74% of the most probable population is in the interval [, μ−3·σ, μ+3·σ]: [0000] P (μ−3 ·σ<X<μ+ 3·σ)=0.9974  (6) [0078] In the subsequent description, the expression “nominal value” refers to the values of the parameter a, h or θ aimed at during fabrication and called hereinafter: a nom , h nom , θ nom . [0079] Moreover, for each of the 3 parameters, the following cases are considered: [0000] a min =a nom −Δa a max =a nom +Δa [0000] h min =h nom −Δh h max =h nom +Δh [0000] θ min =θ nom −Δθ θ max =θ nom +Δθ  (7) [0080] 5) Concerning the Sensor Calibration Operation: [0081] The parameters f 0 , C 1 , C 2 controlled with a certain precision, are distributed according to a distribution centred around a mean with a certain standard deviation. The laws of variations with temperature of the resonators are therefore not identical for all the sensors and the same holds for the calibration coefficients. [0082] To obtain maximum precision of temperature measurement, the calibration coefficients must therefore be calculated individually for each sensor. For this purpose, it is necessary to measure Δf(T) over the whole of the temperature span where the sensor is used so as to fit the coefficients Δ 0 , s, ε and ultimately calculate A 0 , A 1 and A 2 . [0083] This operation is very lengthy and hardly compatible with high-volume production, one seeks therefore to sidestep it. [0084] Among the solutions that may be conceived for accomplishing collective fabrication of calibration-free SAW sensors it is conceivable to use a suite of common calibration coefficients for a set of sensors while maintaining acceptable measurement precision. Moreover, a limited number of sensors can be measured temperature-wise (representative sample) making it possible to determine a mean calibration coefficients suite used for the whole set of sensors. It is then advisable that a suite of calibration coefficients should be common to the largest possible number of sensors, the ideal even being that a suite of coefficients should be common to all the sensors of a given type (defined by the crystalline orientation and the geometry of each of the 2 resonators). This therefore produces what is called a “calibration-free sensor”. [0085] Generally, by considering the law of differential variations with temperature, given by expression (3), it is seen that it is necessary to reduce the dispersions in Δ 0 , s and ε, if one wishes to have a suite of common calibration coefficients for all the sensors, while having good precision of frequency measurement. [0086] One solution is to reduce the dispersions in f 01 , C 11 , C 21 , f 02 , C 12 and C 22 . This leads to carrying out a sorting operation on each of the 3 parameters of the two resonators. This approach is, however, not that adopted in the present invention for the following reasons: one of the objectives is to not measure the sensors temperature-wise individually, therefore the values of C 11 , C 21 , C 12 and C 22 are not known for each sensor. moreover, calculations have shown that a sorting operation such as presented reduces the yields too much if acceptable measurement precision is desired. SUMMARY OF THE INVENTION [0089] In this context and to solve the aforementioned problems, the present invention relates to a novel method of collective fabrication of calibration-free sensors making it possible to retain acceptable measurement precision. [0090] More precisely, one embodiment of the present invention provides a method of collective fabrication of remotely interrogatable sensors, each sensor comprising at least one first resonator and one second resonator, each resonator comprising acoustic wave transducers designed such that they exhibit respectively a first and a second operating frequency, in which the method comprises: the fabrication of a first series of first resonators RT 1i exhibiting a first resonant frequency at ambient temperature f 1i and a first static capacitance C 1i ; the fabrication of a second series of second resonators RT 2j exhibiting a second resonant frequency at ambient temperature f 2 and a second static capacitance C 2j ; a series of electrical measurements of the set of the first series of first resonators and of the set of the second series of second resonators, so as to determine first pairs (f 1i , C 1i ) and second pairs (f 2j , C 2j ) of resonant frequency and of static capacitance of each of the first and second resonators; and a series of matchings of a first resonator RT 1i and of a second resonator RT 2j according to the aggregate of the following two criteria: the dispersion in the difference in resonant frequency (f 1i −f 2j ) is less than a first threshold value (Sf) and the dispersion in the difference in static capacitance (C 1i −C 2j ) is less than a second threshold value of (Sc). [0095] According to a variant of the invention, the electrical measurements are performed by determining measurements of the reflection coefficient S 11 or measurements of admittance Y 11 or else measurements of impedance Z 11 . [0096] According to a variant of the invention the electrical measurements are performed with a network analyzer. [0097] According to a variant of the invention, the measurements of static capacitance are carried out with a high-precision capacimeter. [0098] According to a variant of the invention, the first and second resonant frequencies are similar and situated in the ISM frequency span (433.05 MHz, 434.79 MHz), the threshold value Sf being less than or equal to about a few kHz and/or the threshold value Sc being less than or of the order of a femtoFarad. [0099] According to a variant of the invention, the method comprises for each first resonator of the first series, the selection of a second resonator of the second series so as to satisfy the two matching criteria. [0100] According to a variant of the invention, the method comprises the fabrication of first resonators on a first substrate and the fabrication of second resonators on a second substrate. [0101] According to a variant of the invention, the resonators are produced on quartz substrates of different cuts. [0102] According to a variant of the invention, the first and second substrates are defined by angles of cut θ according to the IEEE standard (YX1)/θ, of 24° and 34° so as to generate resonators of frequency 433 MHz and 434 MHz. [0103] According to a variant of the invention, the method further comprises: the fabrication of first resonators (RT 1i ) on a first substrate (S 1 ) and the fabrication of second resonators (RT i2 ) on a second substrate (S 2 ); unit slicings of first and of second chips comprising respectively the first and second resonators from the said substrates; the matching of a first and of a second chip; the assembling of the pairs of chips in a package. [0108] According to a variant of the invention, the method further comprises: the fabrication of first resonators on a first substrate and the fabrication of second resonators on a second substrate; unit slicings of first and of second chips comprising respectively the first and second resonators from the said substrates; the individual packaging of the first chips and of the second chips in individual packages; the matching of a first and of a second previously packaged chip. [0113] According to a variant of the invention, the sensor is a temperature sensor. [0114] According to a variant of the invention, the first resonators are oriented on the first substrate in a first direction, the second resonators are oriented on the second substrate in a second direction, the said directions corresponding to the directions of propagation of the surface waves, and in such a way that the first direction makes a non-zero angle with the second direction. BRIEF DESCRIPTION OF THE DRAWINGS [0115] The invention will be better understood and other advantages will become apparent on reading the description which follows given by way of non-limiting example and by virtue of the appended figures among which: [0116] FIG. 1 illustrates a resonator structure according to an embodiment of the present invention; [0117] FIG. 2 illustrates the evolution of the resonant frequency (MHz) as a function of h/λ in % for an angle of cut of 24°, for various pairs (θ, a); [0118] FIG. 3 illustrates the evolution of the resonant frequency (MHz) as a function of h/λ in % for an angle of cut of 34°, for various pairs (θ, a); [0119] FIG. 4 illustrates the evolution of the static capacitance (pF) as a function of the metallization ratio for an angle of cut of 24°, for various pairs (θ, h); [0120] FIG. 5 illustrates the evolution of the static capacitance (pF) as a function of the metallization ratio for an angle of cut of 34°, for various pairs (θ, h); [0121] FIG. 6 illustrates the error probability density obtained during a matching operation with a criterion +/−0.2 σ(X) used in a method of collective fabrication according to an embodiment of the present invention; [0122] FIG. 7 the error probability density obtained during a matching operation with a criterion +/−0.1 σ(X) used in a method of collective fabrication according to an embodiment of the present invention. DETAILED DESCRIPTION [0123] A method of collective fabrication of remotely interrogatable passive acoustic wave sensors advantageously produces at least two resonators, arising from the fabrication of two series of resonators, matched pairwise. [0124] Various embodiments of the present invention are described hereinafter within the framework of two resonators exhibiting similar resonant frequencies, typically this is the case with a frequency f 01 ˜433.6 MHz and a frequency f 02 ˜434.4 MHz. [0125] The resonators R 1 can be produced on the surface of an (XY1)/24 quartz cut and the resonators R 2 can be produced on the surface of an (XY1)/34 quartz cut. [0126] Nonetheless, the invention could be implemented with other cuts. [0127] The applicant has started from the finding that it was possible to effect the following approximation: f 02 ≈f 01 and df 02 ≈df 01 . [0128] Typically this approximation can be made when (f 02 −f 01 )/f 01 <<1, this is typically the case when there are two orders of magnitude of difference. [0129] By way of example with a frequency f 01 ˜433.6 MHz and a frequency f 02 ˜434.4 MHz and 3·σ(f 02 )≈3·σ(f 01 )=110 kHz, the approximation is acceptable. [0130] The differential coefficients then become: [0000] s=C 12 ·f 02 −C 11 ·f 01 ≈f 01 ·( C 12 −C 11 ) [0000] ε= C 22 ·f 02 −C 21 ·f 01 ≈f 01 ·( C 22 −C 21 ) [0131] And the dispersions corresponding to the partial derivatives can be written: [0000] ds=df 01 ·( C 12 −C 11 )+ f 01 ·d ( C 12 −C 11 ) [0000] dε=df 01 ·( C 22 −C 21 )+( C 22 −C 21 ) [0132] By way of example let us consider that the resonator R 1 uses the quartz cut (YX1)/24 and the resonator R 2 the cut (YX1)/34. These two resonators can potentially be used for a differential measurement of the temperature in a span of [−20, 160]° C. and using the ISM band [433.05, 434.79] MHz. [0133] Under these conditions we have: [0134] C 11 =6.8 ppm/° C. [0135] C 21 =−30.7 ppb/° C. 2 [0136] C 12 =0.4 ppm/° C. [0137] C 22 =−38.1 ppb/° C. 2 [0138] f 01 ˜433.6 MHz [0139] Δf 01 ≈Δf 02 =3·σ(f 01 )=110 kHz [0140] Δ(C 12 −C 11 )=3·σ(C 12 −C 11 )=0.456 ppm/° C. [0141] Δ(C 22 −C 21 )=3·σ(C 22 −C 21 )=0.41 ppb/° C. 2 [0142] Hence: [0000] Δ   s =  Δ   f 01 ·  C 12 - C 11  + f 01 · Δ  ( C 12 - C 11 ) =  110 * 10 3 * 6.4 * 10 - 6 + 433.6 * 10 6 * 0.456 * 10 - 6 =  0.704 + 197.7216 [0143] It is thus seen that Δf 01 ·|C 12 −C 11 |<<f 01 ·Δ(C 12 −C 11 ) [0144] It is therefore possible to make the approximation Δs≈f 0l ·Δ(C 12 −C 11 ) [0145] Likewise: [0000] Δ   ɛ =  Δ   f 01 ·  C 22 - C 21  + f 01 · Δ  ( C 22 - C 21 ) =  110 * 10 3 * 7.4 * 10 - 9 + 433.6 * 10 6 * 0.41 * 10 - 9 =  814 * 10 - 6 + 177.776 * 10 - 3 [0146] It is thus seen that: Δf 01 ·|C 22 −C 21 |<<f 01 ·Δ(C 22 −C 21 ) [0147] It is therefore possible to make the approximation: Δε≈f 01 ·Δ(C 22 −C 21 ) [0148] Returning to the 3 differential temperature coefficients, their dispersions can therefore be written: [0000] − dΔ 0 =d ( f 02 −f 01 ) [0000] −ds≈f 01 ·d(C 12 −C 11 ) [0000] −dε≈f 01 ·d(C 22 −C 21 )  (8) [0149] This result can be extended to cuts other than those cited above since the orders of magnitude remain the same whatever the cut. [0150] The applicant has shown that the dispersion in the sensor temperature laws depends essentially on the dispersion in the frequency difference which has formed the subject of a patent application filed by the applicant and published under the reference FR 2 907 284, and the dispersions in the differences of CTFs between the 2 resonators. [0151] It is therefore possible to reduce the dispersion in the sensor temperature laws by carrying out a matching of the 2 resonators. That is to say by selecting from among the sets of specimens of resonators R 1 and R 2 pairs of specimens such that: [0000] ( f 02 −f 01 )−ξ( f 02 −f 01 )<( f 02 −f 01 )<( f 02 −f 01 )+ξ( f 02 −f 01 ) [0000] ( C 12 −C 11 )−ξ( C 12 −C 11 )<( C 12 −C 11 )<( C 12 −C 11 )+ξ( C 12 −C 11 ) [0000] ( C 22 −C 21 )−ξ( C 22 −C 21 )<( C 22 −C 21 )<( C 22 −C 21 )+ξ( C 22 −C 21 )  (9) [0152] With ξ the permitted variation in the difference considered. [0153] For example, for the cuts considered, it is possible to carry out a matching satisfying: [0000] 795 kHz<( f 02 −f 01 )<805 kHz with ξ( f 02 −f 01 )=5 kHz [0000] −6.45 ppm/° C.<( C 12 −C 11 )<−6.35 ppm/° C. with ξ( C 12 −C 11 )=0.05 ppm/° C. [0000] 7.35 ppb/° C. 2 <( C 22 −C 21 )<7.45 ppb/° C. 2 with ξ( C 22 −C 21 )=0.05 ppb/° C. 2 [0154] The advantage of matching is to allow much higher yields than a sorting operation on the parameters of resonators taken separately for identical temperature law dispersions. [0155] It is thus apparent that the matching can reduce the temperature law dispersions while maintaining acceptable yields. [0156] It is explained hereinafter how it is thus possible to carry out a matching based on the difference of CTFs without individually measuring the resonators temperature-wise, this constituting a major characteristic of the present invention. [0157] The applicant has started from the finding that the resonators generally use points said to have insensitivity to the width of electrodes so that the resonant frequency is “almost” independent of the latter by virtue of imposed design rules. For this purpose, a point is sought for which: [0000] ∂ f 0 ∂ a  a = a nom = 0 ( 10 ) [0158] The resonant frequency of the resonator then depends only on the metallization thickness and the angle of cut θ. [0159] Moreover, it may easily be shown that the dispersions in resonant frequencies depend very significantly on the dispersions in metallization thickness h. [0160] FIG. 2 illustrates this effect for an exemplary cut with θ=24°. It is apparent that the curves corresponding to variations Δθ of + or −0.05° around 24° all coincide for various values of a (a nom , a min and a max ), the set of curves being relative to the following pairs: (θ min , a min ), (θ min , a nom ), (θ min , a max ), (θ nom , a min ), (θ nom , a nom ), (θ nom , a max ), (θ max , a min ), (θ max , a nom ), (θ max , a max ). [0161] The same phenomenon is obtained with an angle of cut θ=34° and illustrated by FIG. 3 . [0162] It emerges from this set of curves that the resonant frequency of the resonators therefore depends essentially on the dispersions in the metallization thicknesses h. [0163] If a sorting operation is carried out on the resonant frequencies reducing the dispersions in the latter, the dispersions in metallization thicknesses are thus very significantly reduced. [0164] Moreover the applicant has established that the dispersion in static capacitance value depends very significantly on the dispersion in electrode width as illustrated by FIGS. 4 and 5 relating to the evolution of the static capacitances as a function of the normalized metallization ratio a/p and those for the two angles of cut θ=24° and θ=34°, the set of curves being relative (θ min , h min ), (θ min , h nom ), (θ min , h max ), (θ nom , h min ), (θ nom , h nom ), (θ nom , h max ), (θ max , h min ), (θ max , h nom ), (θ max , h max ). [0165] In parallel, the applicant was interested in the static capacitance denoted C 0 corresponding to the capacitance created by the inter-digitated comb transducer and the successive electrodes subjected to differences of electrical potentials. It may be shown that the dispersions in the value of this capacitance depend significantly on the dispersions in electrode widths. [0166] Thus, a sorting operation on the values of static capacitance aimed at reducing their dispersions very significantly reduces the dispersions in electrode widths. The static capacitance of the resonator R 1 is denoted C 01 and the static capacitance of the resonator R 2 is denoted C 02 . [0167] The principle of the present invention rests on the fact of reducing the dispersion in the difference of CTFs (1 st and 2 nd orders) without measuring the resonators individually temperature-wise. [0168] It was demonstrated previously that f 0 , C 1 , C 2 depended solely on a, h, θ, and that it was possible: on the one hand to reduce the dispersion in metallization thickness by carrying out a sorting operation on the resonant frequency and on the other hand to reduce the dispersion in electrode width by carrying out a sorting operation on the static capacitance of the resonators. [0169] It is therefore possible to reduce the dispersion in CTFs without measuring the sensors temperature-wise but by carrying out a measurement of electrical parameters at ambient temperature. However, it is not desirable to carry out a sorting operation on the resonators separately but to use a matching as indicated previously so as not to penalize the yields. [0170] An important aspect of the present invention consists therefore in carrying out a matching of R 1 and R 2 so as to reduce the dispersions in f 02 −f 01 and C 02 −C 01 , so as ultimately to reduce the dispersions in C 12 −C 11 and C 22 −C 21 . [0171] A matching on f 02 −f 01 and C 02 −C 01 appreciably reduces the dispersions in h 2 −h 1 and a 2 −a 1 and the reductions in the dispersions in h 2 −h 1 and a 2 −a 1 obtained generate an appreciable reduction in the dispersions in C 12 −C 11 and C 22 −C 21 . [0172] Advantageously, the measurements of the electrical reflection coefficient S 11 of the resonators are carried out with tips exhibiting a characteristic impedance of 50 ohms and connected to a network analyser. A calibration of the tips (open circuit, short-circuit, suitable load, and correction of the phase shift related to the electrical length of the measurement means) will have been carried out beforehand. [0173] A recording of the variation of the parameter S 11 in the frequency band of interest is performed. The values of the modulus and of the phase of S 11 are therefore available with a frequency sampling increment small enough to correctly evaluate the resonant frequency (on the basis of the maximum of the conductance). A parameter fitting corresponding to the variation of the coefficient S 11 is thereafter typically performed with respect to a model of Butterworth Van Dyck type composed of a series RLC circuit with the static capacitance of the SAW device in parallel. On completion of the fitting operation the static capacitance and the resonant frequency of the resonator at the resonant frequency are therefore known. [0174] An alternative scheme can also be employed; the latter consists in using a high-precision (less than a femtoFarad) capacimeter. [0175] The applicant has estimated the yields of a matching by aggregating the parameters f 02 −f 01 and C 02 −C 01 with the first series of resonators R 1 and the second series of resonators R 2 . [0176] The variables f 01 , f 02 , C 01 , C 02 are considered to be Gaussian random variables. The means and the standard deviations of these variables are those arising from experimental data. It is considered for this purpose that the range is equal to 6 times the standard deviation: [0000] max( X )−min( X )=6·σ( X ) [0177] The standard deviations used are as follows: [0000] σ( f 01 )=σ( f 02 )=37 kHz [0000] σ( C 01 )=σ( C 02 )=7 fF [0178] The algorithm used to carry out the matching does not use any optimization scheme, various pairs of specimens are not tested to maximize the number of matched specimens. The set of specimens of resonators R 1 is simply perused and for each of them a resonator R 2 is selected such that the differences f 02 −f 01 and C 02 −C 01 satisfy the matching criterion. [0179] Finally, in practice, it turns out that the matching is realizable on condition that one limits oneself to a wafer of resonator R 1 and a wafer of resonator R 2 in the choice of the pairs of specimens to be matched. Now, the number of resonators that can be produced on a wafer is approximately 1200. The calculated yields therefore correspond to a matching of 1200 specimens of resonators R 1 and 1200 specimens of resonators R 2 . [0180] Table 1 below presents the values of the yields achievable as a function of the matching criterion: [0000] Matching criterion Matching Matching based on f 02 − f 01 and criterion based on criterion based on C 02 − C 01 f 02 − f 01 in kHz C 02 − C 01 in fF Yield in % +/− σ(X) +/−37 +/−7 99.25 +/−0.5 σ(X) +/−17.5 +/−3.5 97.6 +/−0.2 σ(X) +/−7.4 +/−1.4 87.7 +/−0.1 σ(X) +/−3.7 +/−0.7 71.6 +/−0.05 σ(X) +/−1.85 +/−0.35 47.1 +/−0.01 σ(X) +/−0.37 +/−0.07 3.5 +/−0.005 σ(X) +/−0.185 +/−0.035 1.3 [0181] The two cases of matching to +/−0.2 σ(X) and +/−0.1 σ(X) are particularly interesting in so far as they lead to yields of respectively 87.7% and 71.6%, which are compatible with industrial objectives and impose attainable constraints in terms of dispersion. [0182] Indeed, in each case, the dispersion in a 2 −a 1 is calculated first of all on the basis of the dispersion in C 02 −C 01 by considering that C 02 −C 01 depends solely on a 2 −a 1 . The uncertainty in f 02 −f 01 is then calculated on the basis of the calculated dispersion in a 2 −a 1 and of the dispersion in θ 2 −θ 1 , and this is added to the matching criterion based on f 02 −f 01 to get the total span of variations of f 02 −f 01 that is attributable to h 2 −h 1 (allowance for the case where the variations due to h 2 −h 1 and those due to a 2 −a 1 and θ 2 −θ 1 are of opposite signs). Having calculated the total span of variations of f 02 −f 01 that is attributable to h 2 −h 1 , the dispersion in h 2 −h 1 is calculated. Finally, knowing the dispersions in h 2 −h 1 , a 2 −a 1 and θ 2 −θ 1 , the dispersions in C 12 −C 11 and C 22 −C 21 are calculated. [0183] The results associated with the 2 cases, as well as the intermediate steps, are summarized in Table 2 below. [0000] Matching +/−0.2 σ(X) +/−0.1 σ(X) Criterion (+/−7.4 kHz / +/−1.4 fF) (+/−3.7 kHz / +/−0.7 fF) Δ  ( a 2 - a 1 ) p +/−0.0018 +/−0.0012 Uncertainty   +/−5.5 kHz   +/−5.5 kHz f 02 − f 01 due to Δ(θ 2 − θ 1 ) Uncertainty  +/−1.25 kHz  +/−1.15 kHz f 02 − f 01 due to Δ(a 2 − a 1 ) Total +/−14.15 kHz +/−10.35 kHz Uncertainty Δ  ( h 2 - h 1 ) p +/−0.0068% +/− 0.0054% Order of Differential Temperature Coefficiencs C 1 C 2 C 1 C 2 Δ(C 2 − C 1 ) due +/−0.0305 +/−0.035 +/−0.0285 +/−0.0305 to Δ(h 2 − h 1 ) ppm/° C. ppb/° C 2 . ppm/° C. ppb/° C 2 . Δ(C 2 − C 1 ) due +/−0.0315 +/−0.0315 +/−0.027 +/−0.0305 to Δ(a 2 − a 1 ) ppm/° C. ppb/° C 2 . ppm/° C. ppb/° C 2 . Δ(C 2 − C 1 ) due +/−0.045 +/−0.053 +/−0.045 +/−0.053 to Δ(θ 2 − θ 1 ) ppm/° C. ppb/° C 2 . ppm/° C. ppb/° C 2 . Sum of +/−0.107 +/−0.12 +/−0.101 +/−0.114 Differential ppm/° C. ppb/° C 2 . ppm/° C. ppb/° C 2 . Coefficients Dispersions [0184] On the basis of the previously calculated dispersions (last line of table 2), it is possible to determine the reduction in the error in the measurement of the temperature obtained. [0185] For this purpose, first of all the mean calibration coefficients are calculated on the basis of the mean parameters (f 0 , C 1 , C 2 ) obtained by simulation for each resonator. [0186] Next, random draws are carried out on the basis of the dispersions obtained. [0187] For f 02 −f 01 , a uniform distribution in [−Δ(f 02 −f 01 ), Δ(f 02 −f 01 )] is used since f 02 −f 01 is matched directly and since the matching criterion is small compared with the range of the initial Gaussian. For C 12 −C 11 and C 22 −C 21 , a Gaussian distribution is used based on the dispersions calculated previously (Δ(X)=3·σ(X)). More precisely, we calculate: [0000] 3·σ( s )=Δ s≈f 01 ·Δ( C 12 −C 11 ) [0000] 3·σ(ε)=Δε≈ f 01 ·Δ( C 22 −C 21 ) [0188] Next, Gaussian random draws of s with standard deviation σ(s) and of ε with standard deviation σ(c) are carried out. [0189] The parameters (mean values) used are as follows: [0190] E[C 11 ]=6.8 ppm/° C. [0191] E[C 21 ]=−30.7 ppb/° C. 2 [0192] E[C 12 ]=0.4 ppm/° C. [0193] E[C 22 ]=−38.1 ppb/° C. 2 [0194] E[f 01 ]˜433.4 MHz [0195] E[f 02 ]˜434.5 MHz [0196] The temperature span considered by way of example is defined by Tε[−20, 250]° C. [0197] 1) For a matching to +/−0.2 σ(X): [0000] Δ( f 02 −f 01 )=7.4 kHz [0000] σ( s )=0.036 ppm/° C.*433.4 MHz=15.6 Hz/C [0000] σ(ε)=0.04 ppb/° C. 2 *433.4 MHz=0.0173 Hz/C 2 [0198] We obtain: [0000] 3·σ( Err )=5.75° C. and 99.74% of the population in the interval [−3.62,3.62]° C. [0199] 2) For a matching to +/−0.1 σ(X) [0000] Δ( f 02 −f 01 )=3.7 kHz [0000] σ( s )=0.034 ppm/° C.*433.4 MHz=14.735 Hz/C [0000] σ(ε)=0.038 ppb/° C. 2 *433.4 MHz=0.0165 Hz/C 2 [0200] We obtain: [0000] 3·σ( Err )=3.55° C. and 99.74% of the population in the interval [−2.81,2.81]° C. [0201] FIGS. 6 and 7 show that a matching operation for the criterion +/−0.2 σ(X) leads to the obtaining of a calibration-free temperature sensor operating in the span −20° C. to 250° C. exhibiting a precision of +/−3.6° C. throughout the span with a matching yield of 87.7% and that a matching operation for the criterion +/−0.1σ(X) generates a decrease in the yield (71.6%) but makes it possible to obtain a calibration-free sensor with a better precision (+/−2.8° C.) in the same temperature span. [0202] The many features and advantages of the invention are apparent from the detailed specification, and, thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and, accordingly, all suitable modifications and equivalents may be resorted to that fall within the scope of the invention.

A method of collective fabrication of remotely interrogatable sensors, each sensor comprising at least one first resonator and one second resonator, each resonator comprising acoustic wave transducers designed such that they exhibit respectively a first and a second operating frequency, is provided. The method comprises the fabrication of a first series of first resonators (RT 1i ) exhibiting a first resonant frequency at ambient temperature (f 1i ) and a first static capacitance (C 1i ); the fabrication of a second series of second resonators (RT 2j ) exhibiting a second resonant frequency at ambient temperature (f 2j ) and a second static capacitance (C 2j ); a series of electrical measurements of the set of the first series of first resonators and of the set of the second series of second resonators, so as to determine first pairs (f 1i , C 1i ) and second pairs (f 2j , C 2j ) of resonant frequency and of capacitance of each of the first and second resonators; and a series of matchings of a first resonator (RT 1i ) and of a second resonator (RT 2j ) according to the aggregate of the following two criteria: the dispersion in the difference in resonant frequency (f 1i −f 2j ) is less than a first threshold value (Sf) and the dispersion in the difference in static capacitance (C 1i −C 2j ) is less than a second threshold value (Sc).

CROSS-REFERENCE TO RELATED APPLICATION [0001] The present application claims priority from Japanese application JP2016-023783 filed on Feb. 10, 2016, the content of which is hereby incorporated by reference into this application. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a display device and a manufacturing method thereof, and particularly to a flexible display. [0004] 2. Description of the Related Art [0005] A flat panel display such as an organic electroluminescence (EL) display device has a display panel in which a thin film transistor (TFT), an organic light-emitting diode (OLED) and the like are formed on a substrate. Conventionally, a glass substrate is used for the base member of the display panel. However, recently, the development of a flexible display using a resin film or the like as the base member to enable the flexure of the display panel is under way. [0006] As a structure of the organic EL display device, an element substrate having a display area where an OLED as a display element is formed, and a counter substrate on which a color filter or the like is formed and which is arranged opposite the display area of the element substrate, are bonded together. To secure reliability, the element substrate and the counter substrate are bonded together with a filler held between these substrates. In this case, a method may be used in which a dam having a convex structure is formed at an outer peripheral part of the counter substrate, then the filler is dripped into the dam, and the element substrate and counter substrate are thus bonded together. This dam plays the role of preventing the filler from protruding to the outside. The dam is formed by applying a fluid material onto the outer perimeter of the panel with a dispenser or the like and then hardening the fluid material. [0007] Also, a layer (substrate layer) in which a plurality of the flexible element substrates and counter substrates are arranged is formed on a support plate such as a glass substrate, and after the two substrates are bonded together on each support plate, the resulting structure is divided into a plurality of display panels. SUMMARY OF THE INVENTION [0008] In order to achieve a narrow frame on a high-definition display panel, a dam needs to be patterned with a smaller width and higher precision. However, with the technique of dripping the dam material from the nozzle of the dispenser, high-precision patterning is difficult. [0009] Also, the dam material dripped from the dispenser and hardened is relatively flexible and will not easily crack. Therefore, when dividing the integrally formed plurality of display panels into the individual display panels, laser cutting or the like is used, and a relatively simple technique such as scribe and break cannot be used. [0010] The invention is to provide a display panel which can be processed with higher precision by a simpler technique, when producing display panels by a so-called multiple formation, that is, stacking a substrate disposed a plurality of element substrates and a substrate disposed a plurality of counter substrates and then dividing the stacked substrate into a plurality of display panel, and in which the frame can be narrowed by reducing redundant areas between the substrates, and a manufacturing method thereof. [0011] A display device according to an aspect of the invention includes: an element substrate including a flexible multilayer structure having a resin film as a base member, and having a display area where a display element is formed; a counter substrate including a flexible multilayer structure having a resin film as a base member, and stacked on the display area of the element substrate; and a filler filling a space between the element substrate and the counter substrate. Each of the element substrate and the counter substrate has a rib which includes a covalently or ionically bonding inorganic material and which is in contact with an outer peripheral lateral surface of the multilayer structure. [0012] A manufacturing method of a display device according to another aspect of the invention is a manufacturing method of a display device having a flexible element substrate including a display area where a display element is formed, and a flexible counter substrate bonded to the display area of the element substrate with a filler held between the substrates. The manufacturing method includes: forming a first substrate layer in which a plurality of the element substrate is arranged, on one main surface of a first support plate; forming a second substrate layer in which the counter substrate is provided at each position facing the display area of each of the element substrates in the first substrate layer, on one main surface of a second support plate; bonding the first substrate layer on the first support plate to the second substrate layer on the second support plate and thus forming a substrate layer joined body; and dividing the first substrate layer together with the first support plate, dividing the second substrate layer together with the second support plate, and thereby dividing the substrate layer joined body held between the first and second support plates, into a plurality of parts, each part corresponding to the display device. The forming of the first substrate layer includes forming a ridge-like first rib including a covalently or ionically bonding inorganic material along an edge of the element substrate. The forming of the second substrate layer includes forming a counter area part made of a material including a flexible resin film and arranged opposite the display area, and a second rib including a covalently or ionically bonding inorganic material and in the form of a ridge surrounding the counter area part and higher than the counter area part. The bonding includes filling, with a filler, a recess part in the second substrate layer generated at the counter area part due to a height difference from the second rib. The dividing includes scribing the first and second support plates along the first and second ribs, and flexing and breaking the first and second support plates that are scribed. BRIEF DESCRIPTION OF THE DRAWINGS [0013] FIG. 1 is a schematic view showing a schematic configuration of an organic EL display device according to an embodiment of the invention. [0014] FIG. 2 is a schematic vertical cross-sectional view of a display panel according to the embodiment of the invention. [0015] FIG. 3 is a schematic process flowchart of the manufacturing method of the organic EL display device according to the embodiment of the invention. [0016] FIG. 4 is a schematic vertical cross-sectional view of each of a first substrate layer after the completion of a first substrate layer forming process, and a second substrate layer after the completion of a second substrate layer forming process. [0017] FIG. 5 is a schematic vertical cross-sectional view of the state where the first substrate layer and the second substrate layer are bonded together. [0018] FIG. 6 is a schematic plan view of the first substrate layer and the second substrate layer. DETAILED DESCRIPTION OF THE INVENTION [0019] Hereinafter, a form of embodying the invention (hereinafter referred to as an embodiment) will be described with reference to the drawings. [0020] The disclosure is only an example, and as a matter of course, any change that can be easily thought of by a person skilled in the art without departing from the spirit of the invention should be included in the scope of the invention. In order to clarify the explanation, the drawings may schematically show each part in terms of its width, thickness, shape and the like, compared with the actual configuration. However, this is simply an example and should not limit the interpretation of the invention. Also, elements similar to those described before with reference to already mentioned drawings may be denoted by the same reference signs, and detailed description of these elements may be omitted when appropriate. [0021] The display device according to the embodiment of the invention is an organic EL display device. The organic EL display device is an active-matrix display device and is installed in a television, personal computer, mobile terminal, mobile phone and the like. [0022] FIG. 1 is a schematic view showing a schematic configuration of an organic EL display device 2 according to the embodiment. The organic EL display device 2 has a pixel array part 4 which displays an image, and a drive unit which drives the pixel array part 4 . The organic EL display device 2 is a flat panel display and has a display panel. The display panel includes a display area where the pixel array part 4 is arranged, and a non-display area. [0023] In the pixel array part 4 , an OLED 6 as a display element and a pixel circuit 8 are arranged in the form of a matrix corresponding pixels. The pixel circuit 8 is made up of a plurality of TFTs 10 , 12 and a capacitor 14 . [0024] Meanwhile, the drive unit includes a scanning line drive circuit 20 , a video line drive circuit 22 , a drive power-supply circuit 24 , and a control device 26 . The drive unit drives the pixel circuit 8 to control the light emission of the OLED 6 . [0025] The drive unit can be arranged in the non-display area of the display panel. The drive unit can be formed on the element substrate forming the display panel together with the pixel circuit 8 . Also, the drive unit may be put in an integrated circuit (IC) produced separately from the pixel circuit 8 , and this IC may be installed within the display panel or on a flexible printed circuit (FPC) connected to the display panel. [0026] The scanning line drive circuit 20 is connected to a scanning signal line 28 provided for each horizontal line of pixels (pixel row). The scanning line drive circuit 20 sequentially selects a scanning signal line 28 in response to a timing signal inputted from the control device 26 , and applies a voltage to switch on the lighting TFT 10 , to the selected scanning signal line 28 . [0027] The video line drive circuit 22 is connected to a video signal line 30 provided for each vertical line of pixels (pixel column). The video line drive circuit 22 has a video signal inputted from the control device 26 , and outputs a voltage corresponding to the video signal for the selected pixel row to each video signal line 30 , simultaneously with the selection of the scanning signal line 28 by the scanning line drive circuit 20 . This voltage is written in the capacitor 14 via the lighting TFT 10 , in the selected pixel row. The drive TFT 12 supplies a current corresponding to the written voltage to the OLED 6 , and this causes the OLED 6 of the pixel corresponding to the selected scanning signal line 28 to emit light. [0028] The drive power-supply circuit 24 is connected to a drive power-supply line 32 provided for each pixel column, and supplies a current to the OLED 6 via the drive power-supply line 32 and the drive TFT 12 in the selected pixel row. [0029] Here, the anode of the OLED 6 is connected to the drive TFT 12 . Meanwhile, the cathode of each OLED 6 is basically connected to the ground potential, and the cathodes of the OLEDs 6 of all the pixels are formed by a common electrode. [0030] FIG. 2 is a schematic vertical cross-sectional view of a display panel 40 . The display panel 40 includes an element substrate 42 and a counter substrate 44 bonded to each other. [0031] The element substrate 42 has a display area 46 and a non-display area 48 . In the display area 46 of the element substrate 42 , the pixel array part 4 is provided as already described. In the non-display area 48 , a wiring 50 led out of the pixel array part 4 in the adjacent display area 46 is formed. Also, in the non-display area 48 , a terminal 52 for connecting the drive unit to the wiring 50 or a circuit of the drive unit can be formed, and an IC can be arranged. FIG. 2 shows an example in which an FPC 54 is connected to the terminal 52 provided in the non-display area 48 . [0032] The pixel array part 4 , the wiring 50 , the terminal 52 and the like are formed on one main surface of a base member 56 made of a flexible resin film. For example, the base member 56 can be formed using polyimide, epoxy, acrylic, polyethylene naphthalate, and a thermoplastic fluorine resin such as tetrafluoroethylene-ethylene copolymer. [0033] The pixel array part 4 has a multilayer structure including a circuit layer in which electronic circuits such as the pixel circuit 8 , the scanning signal line 28 , the video signal line 30 , and the drive power-supply line 32 are formed, and an OLED layer in which an OLED is formed, or the like. The OLED layer includes a pixel electrode, an organic material multilayer part, a common electrode, and a bank. The pixel electrode, the common electrode, and the organic material multilayer part held between these electrodes form the OLED. Also, basically, the common electrode contacts the organic material multilayer parts of all the pixels in the display area. Meanwhile, the pixel electrode is formed separately for each pixel and is connected to the drive TFT 12 shown in FIG. 1 and formed in the circuit layer. The common electrode and the pixel electrode is formed using a transparent conductive material such as IZO (indium zinc oxide) or ITO (indium tin oxide). The organic material multilayer part has a light emitting layer. The light emitting layer has holes and electrons injected therein in response to the voltage applied to both electrodes, and emits light due to the recombination of these holes and electrons. [0034] The OLED layer is stacked on the circuit layer, and a cover layer 58 is stacked on the OLED layer. The cover layer 58 is made of a film with a moisture-proof function and protects the OLED from property deterioration due to moisture. For example, a layer made of silicon nitride (SiN) is stacked as the cover layer 58 . [0035] An end part 60 made of a covalently bonding inorganic material or an ionically bonding inorganic material is in tight contact with the outer peripheral lateral surface of the base member 56 . The end part 60 has a moisture-proof function on the lateral surface of the base member 56 or the like. Also, the back side of the element substrate 42 , that is, the side opposite to the side where the pixel array part 4 is formed, of the base member 56 , is covered by a barrier layer 62 having a moisture-proof function. [0036] The counter substrate 44 is stacked on the display area 46 of the element substrate 42 . The counter substrate 44 has a counter area part which is arranged opposite the display area 46 , and an end part 64 which surrounds the counter area part and is higher than the counter area part. The counter area part has a multilayer structure using a flexible resin film as a base member 66 , and a color filter and a barrier layer (hereinafter these two are collectively referred to as a color filter layer 68 ) and the like are stacked on one main surface of the base member 66 . The base member 66 can be formed using the materials mentioned above with respect to the base member 56 , for example. The end part 64 is made of a covalently bonding inorganic material or an ionically bonding inorganic material and is in tight contact with the outer peripheral lateral surface of the base member 66 . The end part 64 has a moisture-proof function on the lateral surface of the base member 66 and the like. Also, the back side of the counter substrate 44 , that is, the side opposite to the side where the color filter layer 68 is formed, of the base member 66 , is covered by a barrier layer 70 having a moisture-proof function. [0037] In the element substrate 42 , the cover layer 58 may cover the base member 56 in an area excluding the wiring 50 , of the non-display area 48 . Also, an underlying layer made up of a silicon nitride film and a silicon oxide film may be provided between the pixel array part 4 and the base member 56 , and this underlying layer may exist in the entirety of the display area 46 and the non-display area 48 . Since the cover layer 58 , the end part 60 , the barrier layer 62 , and the underlying layer, which do not easily pass oxygen or moisture through, are thus provided on the top surface, the bottom surface, and the lateral surface of the base member 56 , moisture or oxygen does not enter the base member 56 . Similarly, in the base member 66 of the counter substrate 44 , since the color filter layer 68 , the end part 64 , and the barrier layer 70 , which do not easily pass moisture or oxygen through, are provided on the top surface, the bottom surface, and the lateral surface, moisture or oxygen does not enter the base member 66 . [0038] The element substrate 42 and the counter substrate 44 are bonded together in such a way that the surface where the pixel array part 4 and the like are formed, of the element substrate 42 , and the surface where the color filter layer 68 is formed, face each other. Here, the surface where color filter layer 68 is formed, of the counter substrate 44 , is a recess part in the counter area part due to the height difference between the end part 64 and the counter area part. This recess part is filled with a filler 72 when bonding the two substrates 42 , 44 together. The filler 72 fills the space between the element substrate 42 and the counter substrate 44 and hardens and thus bonds the two substrates together. [0039] In the part where the edge of the element substrate 42 and the edge of the counter substrate 44 coincide with each other, the top surface of the end part 60 and the top surface of the end part 64 face each other. In this part, the two substrate 42 , 44 are in tight contact with each other, preventing the filler 72 from leaking out. Meanwhile, in the part where the edge of the counter substrate 44 and the edge of the element substrate 42 do not coincide with each other, specifically, in the boundary part between the display area 46 and the non-display area 48 of the element substrate 42 , a dam material 74 is stacked on the element substrate 42 in order to prevent the formation of a space between the top surface of the end part 64 and the top surface of the element substrate 42 and the entry of the filler 72 into the space. [0040] To protect the joined body of the element substrate 42 and the counter substrate 44 , protection films 76 , 78 are bonded onto the outer surfaces of the substrates, that is, onto the barrier layers 62 , 70 . [0041] Next, the manufacturing method of the organic EL display device 2 will be described. The manufacturing method of the organic EL display device 2 according to the invention is characterized by the manufacturing method of the display panel 40 . In this manufacturing method, the multilayer structures of a plurality of display panels 40 are formed integrally. [0042] FIG. 3 is a schematic process flowchart of the manufacturing method. This process flow is made up of a series of steps for forming a first substrate layer in which the structures of a plurality of element substrates 42 are arranged on one main surface of a first support plate (first substrate layer forming process: Steps S 10 to S 15 ), a series of steps for forming a second substrate layer in which the structure of each counter substrate 44 is provided at a position facing the display area 46 of each element substrate 42 in the first substrate layer, on one main surface of a second support plate (second substrate layer forming process: Steps S 20 to S 24 ), and a series of steps (Steps S 30 to S 33 ) for assembling the first substrate layer and the second substrate layer into the display panel 40 . [0043] FIG. 4 is a schematic vertical cross-sectional view of the first substrate layer after the completion of the first substrate layer forming process and the second substrate layer after the completion of the second substrate forming process. In this illustration, the direction of and horizontal positional relation between the two substrate layers are the same as those at the time of bonding these substrate layers. FIG. 5 is a schematic cross-sectional view of the state where the two substrate layers are bonded together. [0044] FIG. 6 is a schematic plan view of a first substrate layer 200 and a second substrate layer 202 . The position of the cross section shown in FIGS. 4 and 5 is the same as in FIG. 2 , and this position is indicated by a segment A-A in FIG. 6 . In FIG. 6 , one element substrate 42 arranged in the first substrate layer 200 and one counter substrate 44 arranged in the second substrate layer 202 are indicated by hatching. The element substrate 42 has a rectangular planar shape. In FIG. 6 , the area above the dotted line in this rectangle is the display area 46 , and the area below the dotted line is the non-display area 48 . The counter substrate 44 has a rectangular planar shape, too, and has a shape basically coincident with the display area 46 of the element substrate 42 . When the first substrate layer 200 and the second substrate layer 202 are bonded together, three sides of the four sides forming the outline of the counter substrate 44 overlap with the outline of the element substrate 42 , and the remaining one side is situated at the boundary between the display area 46 and the non-display area 48 . [0045] Since the element substrate 42 is flexible, a support plate 90 which holds the element substrate 42 in a flat state is prepared at the beginning of the first substrate layer forming process (Step S 10 ). As the support plate 90 , a material suitable for the scribe and break technique is used. For example, the support plate 90 is formed using glass. In this embodiment, in order to produce a plurality of display panels 40 in one shot as described above, the support plate 90 in a shape and size that allows a plurality of element substrate 42 to be arranged thereon is prepared. In the example shown in FIG. 6 , three by three element substrates 42 , in the directions of length and width, are arranged on the support plate 90 . [0046] First, the first substrate layer forming process will be described. A sacrificial layer (not illustrated) used at the time of stripping the element substrate 42 from the support plate 90 , and the barrier layer 62 having a moisture-proof function are stacked in order on the support plate 90 (Step S 11 ). The sacrificial layer is preferably made of a metal or metal oxide. Titanium (Ti), tungsten (W) or oxides thereof may be used. The barrier layer 62 is made up of a silicon nitride film, silicon oxide film, silicon carbonitride film, silicon carbide film, or multilayer structure of these films. [0047] A ridge-like first rib 92 is formed using a covalently or ionically bonding inorganic material, on the barrier layer 62 along the edge of the element substrate 42 (Step S 12 ). In FIG. 6 , the element substrate 42 is in contact with the edge of the adjacent element substrate 42 , and these element substrates 42 share the rib 92 provided along the side in the direction of length. Meanwhile, in the example of FIG. 6 , since a margin area 94 is provided between the element substrates 42 next to each other in the direction of length, the rib 92 provided along the side in the direction of width of the element substrates 42 is not shared between the element substrates 42 . [0048] As a method for forming the rib 92 , patterning using a photolithography technique, a printing method, an aerosol deposition method, sheet pasting or the like can be used. Incidentally, the aerosol deposition method is a high-speed coating method in which fine particles of ceramics, metal or the like as a powder material are sprayed, thus enabling solidification and densification at room temperature without needing a binder or pre-heating of the base member. The rib 92 is formed of a covalently or ionically bonding inorganic material as described above, due to its characteristic of being susceptible to cracking, compared with an organic material like resin or a metal, and therefore suitable for the scribe and break technique. For example, the rib 92 is formed of SiN, silicon oxide (SiO), ITO or the like. Moreover, the same material as the sacrificial layer may be used for the rib 92 , and a metal oxide or metal nitride may be used. A material that can easily crack and does not easily pass water and oxygen through is preferable for the rib 92 . The thickness (height) of the rib 92 is set to be basically the same as or slightly greater than the thickness of the multilayer structure that is subsequently formed in the area surrounded by the rib 92 . [0049] In the area surrounded by the rib 92 , the base member 56 of the flexible resin film is stacked (Step S 13 ). Further thereon, the circuit layer of the pixel array part 4 , the OLED layer and the like are formed in the display area 46 , whereas the wiring 50 , the terminal 52 and the like are formed in the non-display area 48 , and the cover layer 58 is formed thereon (Step S 14 ). [0050] After the main structure of the element substrate 42 such as the pixel array part 4 and the wiring 50 is formed on the base member 56 in Step S 14 , the dam material 74 (seal part) having a thickness corresponding to the height difference between the position of the rib 92 and an area arranged opposite the end part 64 of the counter substrate 44 at the boundary between the display area 46 and the non-display area 48 is formed in this area (Step S 15 ). Thus, the first substrate layer 200 is formed on the surface of the support plate 90 . [0051] Next, the second substrate layer forming process will be described. In this process, as in the first substrate layer forming process, a support plate 96 is prepared (Step S 20 ), and a sacrificial layer (not illustrated) and the barrier layer 70 are stacked thereon in order (Step S 21 ). Also, a ridge-like second rib 98 is formed using a covalently or ionically bonding inorganic material, on the barrier layer 70 along the edge of the counter substrate 44 (Step S 22 ). The rib 98 can be formed using a technique and material that are basically similar to those of the rib 92 . The thickness (height) of the rib 98 is set to be basically greater than the thickness of the multilayer structure subsequently formed in the area (counter area part) surrounded by the rib 98 . The same material as the barrier layer 62 may be used for the barrier layer 70 , and the same material as the material used at the time of forming the first substrate layer may be used for the sacrificial layer. [0052] Also, in FIG. 6 , since the counter substrate 44 is stacked on the display area 46 of the element substrate 42 , the counter substrates 44 next to each other in the direction of width are in contact with each other at the edge, similarly to the element substrates 42 , and these counter substrates 44 share the rib 98 provided along the side in the direction of length, whereas the rib 98 provided along the side in the direction of width is not shared between the counter substrates 44 . [0053] In the area surrounded by the rib 98 , the base member 66 of the flexible resin film is stacked (Step S 23 ), and the color filter, the barrier layer and the like forming the color filter layer 68 are formed further thereon (Step S 24 ). Thus, the second substrate layer 202 is formed on the surface of the support plate 96 . As described above, the same material as the base member 56 , for example, can be used for the base member 66 . [0054] FIG. 4 shows the first substrate layer 200 and the second substrate layer 202 produced by the above processes. Next, the process of assembling these substrate layers into the display panel 40 . The counter area part of the second substrate layer 202 , that is, the surface of the area surrounded by the rib 98 , is a recess part by having the rib 98 formed to be higher than the counter area part. This recess part is filled with the filler 72 , using a dispenser or the like (Step S 30 ). Then, for example, the support plate 96 is horizontally placed, with the surface where the second substrate layer 202 is formed facing upward, and the support plate 90 is overlaid on the support plate 96 , with the surface where the first substrate layer 200 is formed facing downward. Then, the first substrate layer 200 and the second substrate layer 202 are bonded together into the state shown in FIG. 5 (Step S 31 ). [0055] Here, the filler 72 may fill the gap between the two substrate layers when the first substrate layer 200 and the second substrate layer 202 are bonded together. That is, the filler 72 need not necessarily be spread on the entire surface of the recess part at the stage of Step S 30 . For example, the filler 72 may be scattered inside the recess part in Step S 30 , and the filter 72 can be evenly spread in the gap when the two substrate layers are bonded in a vacuum. [0056] Also, a filler 100 may be scattered in the area opposite the margin area 94 of the first substrate layer 200 , of the second substrate layer 202 , and may be used as a spacer for maintaining the gap between the two substrate layers at the part corresponding to the non-display area 48 of the element substrate 42 . [0057] After the fillers 72 , 100 are hardened, the joined body of the substrate layers 200 , 202 is divided together with the support plates 90 , 96 into the respective display panels 40 by using the scribe and break technique (Step S 32 ). Specifically, each of the support plates 90 , 96 is scribed and the substrate layers are flexed and broken together with the support plates. [0058] Scribe lines are formed along the ribs 92 , 98 . Particularly, at the part where the rib is shared among the element substrates 42 adjacent to each other in the first substrate layer 200 , or the counter substrates 44 adjacent to each other in the second substrate layer 202 , the scribe line is set within the width of the rib, so that the rib is left on both adjacent substrates after breaking. In this embodiment, such a shared part of the rib is the part extending in the direction of length, of the ribs 92 , 98 shown in FIG. 6 . [0059] Meanwhile, at the part of the rib that is not shared among the element substrates 42 adjacent to each other in the first substrate layer 200 or the counter substrates 44 adjacent to each other in the second substrate layer 202 , the scribe line may be set along the edge on the side of the rib that is not adjacent to the element substrate 42 or the counter substrate 44 , so that, at this part, the rib is left in its full width on the adjacent substrate. In this embodiment, such a non-shared part of the rib is the part extending in the direction of width, of the ribs 92 , 98 shown in FIG. 6 . However, the scribe line is set within the width of the rib at this part as well, thus achieving a narrower frame. Specifically, scribe lines are set at the positions α 1 , α 2 on the first substrate layer 200 and the positions β 1 , β 2 on the second substrate layer 202 shown in FIG. 5 , and the substrate layers are then broken. [0060] The ribs 92 , 98 after the breaking form the outer peripheral end parts 60 , 64 of the element substrate 42 and the counter substrate 44 , respectively. [0061] Here, the dam material 74 is formed in the area facing a part of a rib 98 a shown in FIG. 5 . The rib 98 a is the rib 98 situated at the boundary between the display area 46 and the non-display area 48 , and the part of the rib 98 a belongs to the counter substrate 44 after the braking. That is, in the case where the scribe line is set within the width of the rib 98 a as described above, the forming area for the dam material 74 and the position of the scribe line are adjusted so that the dame material 74 will not protrude to the outside from the position β 2 of the scribe line. If the dam material 74 is laid across the break position, the dame material 74 may not be divided, or a part 102 that should be removed by the division, of the second substrate layer 202 , may remain attached to the element substrate 42 even after the division. On the other hand, if the dam material 74 is held on the inside from the position β 2 of the scribe line, this part 102 can be easily removed by breaking. [0062] After the breaking, the cover layer 58 and the like stacked on the terminal 52 are removed, exposing the terminal 52 . Then, the process of connecting the FPC 54 to the terminal 52 , or the like, is carried out. [0063] Subsequently, the support plates 90 , 96 are separated from the joined body of the element substrate 42 and the counter substrate 44 divided for each display panel 40 by the breaking (Step S 33 ). For the separation of the support plates, methods such as evaporating the sacrificial layers between the barrier layers 62 , 70 and the support plates 90 , 96 by laser ablation, or dissolving the sacrificial layers by etching, may be used. After separating the support plates, the protection films 76 , 78 are stuck to the back sides of the element substrate 42 and the counter substrate 44 . Thus, the structure of the display panel 40 shown in FIG. 2 is basically achieved. [0064] In the embodiment, the case of an organic EL display device is illustrated as a disclosed example of the display device. However, as other application examples, any flat panel display devices can be employed, such as a liquid crystal display device, other types of self-light-emitting display device, electronic paper display device having an electrophoretic element or the like, and quantum dot display device. Also, as a matter of course, display devices of medium and small sizes to large size can be used without any particular limitation. [0065] A person skilled in the art can readily think of various changes and modifications within the scope of the technical idea of the invention, and such changes and modifications should be understood as falling within the scope of the invention. For example, the addition or deletion of a component, or a design change suitably made to the foregoing embodiment by a person skilled in the art, or the addition or omission of a process, or a condition change in the embodiment is included in the scope of the invention as long as such change or the like includes the spirit of the invention. [0066] Also, as a matter of course, other advantageous effects that may be achieved by the configurations described in the embodiment should be understood as being achieved by the invention if those effects are clear from the specification or can be readily thought of by a person skilled in the art. [0067] While there have been described what are at present considered to be certain embodiments of the invention, it will be understood that various modifications may be made thereto, and it is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention.

Simple and high-precision processing, and narrowing of the frame are to be facilitated at the time of preparing display panels by multiple formation. After bonding a first substrate layer in which a plurality of element substrates is formed on a support plate and a second substrate layer in which a plurality of counter substrates is formed on a support plate, these substrate layers are divided into a plurality of display panels. Ridge-like ribs of a covalently or ionically bonding inorganic material are formed along edges of the element substrate and the counter substrate. The dividing includes scribing the support plates along the ribs, and flexing and breaking the support plates.

The present application claims priority from U.S. Provisional patent application No. 60/406,661, filed Aug. 29, 2002. FIELD OF THE INVENTION The present invention relates to improving the luminance and the operating stability of phosphors used for full color ac electroluminescent displays employing thick film dielectric layers with a high dielectric constant. More specifically, the invention relates to an improved thin film fine grained zinc sulfide phosphor in combination with a structure and/or substance to minimize or prevent reaction of the fine grained phosphor with oxygen for use in electroluminescent displays. BACKGROUND OF THE INVENTION Thick film dielectric structures as exemplified by U.S. Pat. No. 5,432,015 are known and exhibit superior characteristics to that of traditional TFEL displays. High performance red, green and blue phosphor materials have been developed for use with thick film dielectric structures to provide increased luminance performance. These phosphor materials include europium activated barium thioaluminate based materials for blue emission, terbium activated zinc sulfide, manganese activated magnesium zinc sulfide or europium activated calcium thioaluminate based materials for green emission, as well as traditional manganese activated zinc sulfide that can be appropriately filtered for red emission. The thin film phosphor materials used for red, green and blue sub-pixels must be patterned using photolithographic techniques employing solvent solutions for high resolution displays. Traces of these solutions remaining in the display following photolithographic processing together with reaction of moisture or oxygen present in the processing environment may react chemically with certain phosphor materials that are sensitive to oxidation or hydrolysis reactions to cause performance degradation of the completed display. Continued chemical reactions during operation of the display may cause continued performance degradation thereby shortening the life of the display. To overcome such performance degradation problems, researchers have proposed the use of various materials in conjunction with phosphor materials including zinc sulfide rare earth metal activated phosphors as disclosed for example in U.S. Pat. Nos. 6,048,616 and 6,379,583. Ihara et al., ( Journal of the Electrochemical Society 149 (2002) pp H72-H75) discloses the use of glass to encapsulate nanocrystalline terbium activated zinc sulfide grains. Such encapsulated nanocrystalline grains led to substantially increased photoluminescence and cathodoluminescence as compared to bulk terbium activated zinc sulfide that was attributed to an increase in the transition probability for the decay of the terbium atom from its excited state. The glass coating prevented loss of sulfur and terbium relative to the zinc content of the particles under electron bombardment, whereas uncoated particles with the same diameter showed a significant loss of sulfur and some loss of terbium under the same conditions. The sulfur loss was due to displacement of sulfur from the zinc sulfide by oxygen. However, this reference teaches that the glass coating method is not applicable to the coating of bulk materials such as deposited films and therefore the use of the coated powders for electroluminescent applications was not considered where the factors controlling luminance are different than they are for photoluminescence or cathodoluminescence. Also, a reduction in the grain size of manganese activated zinc sulfide phosphor films in electroluminescence applications did not facilitate an improvement in luminance, but rather decreased the luminance, showing that a reduction in grain size does not necessarily lead to increased luminance. Mikami et al., (Proceedings of the 6 th International Conference on the Science and Technology of Display Phosphors (2000) pp. 61-4) disclose the use of sputtered silicon nitride layers to encapsulate a terbium activated zinc magnesium sulfide thin film phosphor layer in an electroluminescent device to improve the emission spectrum for use as a green phosphor. Luminosity or luminance stability of the device was not addressed. J. Ohwaki et al., (Review of the Electrical Communications laboratories Vol. 35, 1987) disclose the use of chemical vapour deposition to deposit silicon nitride on an electron beam deposited terbium activated zinc sulfide phosphor film to improve its luminance stability. The silicon nitride layer was to provide a barrier to prevent moisture incursion into the conventional type of zinc sulfide phosphor. Further, chemical vapour deposition processes are difficult to adapt to large area electroluminescent displays for television and other large format display applications and suffer cost and safety disadvantages associated with the handling of volatile precursor chemicals and remediation of effluent gases required for the processes. U.S. Pat. No. 4,188,565 discloses the use of oxygen-containing insulator silicon nitride layers for use with a manganese activated zinc sulfide phosphor where the oxygen content in the silicon nitride is between 0.1 and 10 mole percent. It is taught in this patent that silicon nitride that does not contain oxygen is unsatisfactory because it does not form a sufficiently strong bond with the phosphor material to prevent delamination. The above noted patent further teaches deposition of the oxygen doped silicon nitride by the use of a sputtering process in a low-pressure atmosphere of nitrogen or a nitrogen-argon mixture containing nitrous oxide. A second insulator layer in combination with the oxygen doped silicon nitride layer is also used to prevent degradation of the phosphor material due to reaction with ambient moisture. U.S. Pat. No. 4,721,631 discloses deposition of a silicon nitride layer or a silicon oxynitride layer on top of a manganese activated zinc sulfide phosphor film using a plasma chemical vapour deposition method. In this method the process gas for the deposition includes nitrogen and silane rather than ammonia and silane in order to exclude hydrogen from the process since hydrogen can react with sulfur bearing phosphor materials to form hydrogen sulfide, thereby degrading the phosphor performance. It is disclosed that silicon nitride layers deposited using the ammonia free plasma chemical vapour deposition process enable equivalent performance results with manganese activated zinc sulfide phosphors to those obtained with sputtered silicon nitride layers, whereas silicon nitride layers deposited using ammonia yield inferior results. U.S. Pat. No. 4,880,661 discloses that a manganese-activated zinc sulfide phosphor film cannot successfully be deposited on top of a silicon nitride film using chemical vapour deposition due to its hydrogen concentration. The hydrogen migrates into the phosphor during thermal annealing of the deposited phosphor, causing degradation by loss of sulfur due to reaction with the hydrogen. U.S. Pat. No. 4,897,319 discloses an electroluminescent device with a double-stack insulator on either side of a manganese-activated zinc sulfide phosphor layer to improve the luminance and energy efficiency of the device. One of the stack members is silicon oxynitride and the other is barium tantalate. The order of the members are reversed on the two sides with the silicon oxynitride layer in contact with the phosphor film on one side and the barium tantalate oxide layer in contact with the phosphor on the opposite side. U.S. Pat. No. 5,314,759 discloses an electroluminescent display that includes a terbium activated zinc sulfide phosphor layer deposited by Atomic Layer Epitaxy (ALE) and a layer of samarium doped zinc aluminum oxide. U.S. Pat. No. 5,496,597 discloses a method for making a multilayer alkaline-earth sulfide-metal oxide structure for electroluminescent displays. The phosphor layer has dielectric layers on each side composed of various materials including aluminum oxide. U.S. Pat. No. 5,598,059 discloses various phosphors including zinc sulfide doped with terbium and having insulating layers of various materials including aluminum oxide. U.S. Pat. No. 5,602,445 discloses various phosphors with layered construction and having insulating and buffer layers about the phosphor. In one aspect, zinc sulfide is used to sandwich a calcium chloride or strontium chloride rare earth activated phosphor. U.S. Pat. No. 5,644,190 discloses the use of insulator layers of silicon oxide on both sides of phosphor layers of various materials including manganese activated zinc gallium oxide and zinc cadmium sulfide activated with silver and indium oxide. WO 00/70917 discloses an electroluminescent laminate that includes a rate earth activated zinc sulfide material having a diffusion barrier layer of zinc sulfide. While the aforementioned references and patents may teach the use of a conventional large grained rare earth activated zinc sulfide phosphor with certain types of “barrier” or “insulator” materials” for the purpose of preventing reaction of the phosphor with water from the ambient environment or some other “stabilizing” type function, there remains a need to provide an improved zinc sulfide rare earth activated phosphor that has both improved luminance and a long operating life with minimal degradation. SUMMARY OF THE INVENTION The present invention is directed to a thick film electroluminescent device employing a thin film zinc sulfide phosphor doped with a rare earth activator species that has an improved luminance and a long operating life with minimal luminance degradation. Conventional teachings in EL technology utilize phosphors with a large grain size in order to achieve good performance. In contrast, in the present invention an improved rare earth activated zinc sulfide phosphor is achieved by making the zinc sulfide thin film phosphor fine grained. The use of the fine grained zinc sulfide phosphor may be combined with a structure and/or substance to minimize or prevent reaction of the fine grained phosphor with oxygen within a thick film electroluminescent display. In aspects, a structure or substance suitable for use with the fine grained phosphor may be selected from: interface modifying layers on one or both sides of the phosphor film to improve the stability of the interface between the phosphor film and the rest of the device structure; a hermetic enclosure for the electroluminescent display; an oxygen getter incorporated into the display; and any combination thereof including having all of the structures and substances present together in a single display. Zinc sulfide based phosphor films are susceptible to degradation due to incorporation of oxygen into the film, either by replacement of sulfur by oxygen in the crystal lattice, or by incorporation of oxygen into the grain boundaries. In fact, the reaction rate with oxygen is increased if the grain size is small or if the zinc sulfide crystal lattice contains a high density of crystal defects. The luminance of zinc sulfide based sulfide phosphor materials is adversely affected by oxygen incorporation. The source of the oxygen may be the internal structure of the display device outside of the phosphor film, or it may be the ambient environment. The rate of oxygen incorporation may be accelerated by the presence of water in the structure. The rate of reaction is typically higher if the crystal grain size is smaller, due in part to the ability of oxygen to diffuse within the film along grain boundaries much more quickly than it can diffuse through the crystal lattice of the individual grains. To overcome such difficulties, the Applicant's have developed thin film zinc sulfide phosphors doped with rare earth activator species where the phosphor material is fine grained with a preferred morphology and with a preferred crystal structure to improve luminance. The use of such fine grained phosphors may be combined with a structure and/or substance to minimize or prevent reaction of the fine grained phosphor with oxygen. In one aspect, interface modifying layers may be employed to help limit the rate at which oxygen can react with the phosphor material and facilitates the use of a fine grained phosphor. The interface modifying layer is preferably oxygen-free and hydrogen-free, although it may contain oxygen that is sufficiently tightly bonded that it cannot react with the adjacent phosphor material. In another aspect, a hermetic enclosure may be provided to minimize exposure of the fine grained phosphor material to oxygen. Such an enclosure may comprise an optically transparent cover plate disposed over the laminated structure comprising the phosphor layer deposited onto the device substrate with a sealing bead between the substrate and the cover plate beyond the perimeter of the laminated structure. The sealing bead may comprise a glass frit or polymeric material as is known to those of skill in the art. Alternatively it may be an oxygen-impermeable sealing layer deposited over, and extending everywhere beyond the perimeter of the laminated structure to prevent exposure of the phosphor to oxygen. In a further aspect, an oxygen getter may be introduced into the display to remove traces of oxygen. Getter materials are known to those of skill in the art. A getter should be selected that has a greater affinity for oxygen than the phosphor material during the operational lifetime of the electroluminescent device. The getter should be positioned within the hermetic enclosure to capture any residual oxygen within the enclosure or that may permeate into the enclosure during the display life. It is preferable that the getter be positioned so that it is not directly incorporated into or in contact with the fine grained phosphor material. According to an aspect of the present invention is an improved phosphor for an electroluminescent display, said phosphor comprising; a thin fine grained rare earth metal activated zinc sulfide phosphor material. According to another aspect of the present invention is an improved phosphor for an electroluminescent display, said phosphor comprising; a thin fine grained rare earth metal activated zinc sulfide phosphor material, wherein said phosphor has a crystal grain dimension of up to about 50 nm. According to another aspect of the present invention is an improved phosphor for an electroluminescent display, said phosphor comprising; a thin fine grained rare earth metal activated zinc sulfide phosphor material used in combination with a structure or substance to minimize or prevent reaction of said fine grained phosphor with oxygen. According to still another aspect of the present invention is a thick film dielectric electroluminescent device comprising; a thin film fine grained rare earth metal activated zinc sulfide phosphor; and a structure and/or substance to minimize or prevent reaction of the fine grained phosphor with oxygen, wherein said structure or substance comprises one or more of; i) interface modifying layers on one or both sides of the phosphor film to improve the stability of the interface between the phosphor film and the rest of the device; ii) a hermetic enclosure for the electroluminescent device; and iii) an oxygen getter incorporated into the device. According to yet another aspect of the invention is a thick film dielectric electroluminescent device comprising; a thin phosphor layer of formula ZnS:Re, wherein said phosphor layer has a crystal grain size of up to about 50 nm and Re is selected from terbium and europium; and a structure and/or substance to minimize or prevent reaction of the fine grained phosphor with oxygen, wherein said structure or substance comprises one or more of; i) interface modifying layers on one or both sides of the phosphor film to improve the stability of the interface between the phosphor film and the rest of the device; ii) a hermetic enclosure for the electroluminescent device; and iii) an oxygen getter incorporated into the device. According to yet another aspect of the present invention is an improved phosphor structure for an electroluminescent display, said structure comprising; a thin fine-grained rare earth metal activated zinc sulfide phosphor layer; and an interface modifying layer adjacent one or both sides of said phosphor layer. According to an aspect of the present invention is an improved phosphor structure for an electroluminescent display, said structure comprising; a thin phosphor layer of formula ZnS:Re, wherein said phosphor layer has a crystal grain size of up to about 50 nm and Re is selected from terbium and europium; and an interface modifying layer adjacent one or both sides of said phosphor layer wherein said modifying layer is selected from the group consisting of pure zinc sulfide, hydroxyl ion free alumina (Al 2 O 3 ) or alumina containing hydroxyl ions at a concentration sufficiently low that it does not contribute to phosphor degradation, aluminum nitride, silicon nitride containing no oxygen (Si 3 N 4 ) and silicon nitride with a sufficiently low oxygen content that the oxygen is sufficiently tightly bound so as not to contribute to phosphor degradation. According to an aspect of the present invention is an improved phosphor structure for an electroluminescent display, said structure comprising; a thin phosphor layer of formula ZnS:Re, wherein said phosphor layer has a sphalerite crystal structure of grain size of about 20 to about 50 nm and Re is selected from terbium and europium; and an interface modifying layer adjacent one or both sides of said phosphor layer wherein said modifying layer is selected from the group consisting of pure zinc sulfide, hydroxyl ion free alumina (Al 2 O 3 ) or alumina containing hydroxyl ions at a concentration sufficiently low that it does not contribute to phosphor degradation, aluminum nitride, silicon nitride containing no oxygen (Si 3 N 4 ) and silicon nitride with a sufficiently low oxygen content that the oxygen is sufficiently tightly bound so as not to contribute to phosphor degradation. According to yet another aspect of the present invention is an improved phosphor structure for an electroluminescent display, said structure comprising; a thin phosphor layer of formula ZnS:Tb, wherein said phosphor layer has a crystal grain size of about 20 nm to about 50 nm; and an interface modifying layer adjacent one or both sides of said phosphor layer wherein said modifying layer is pure zinc sulfide. According to another aspect of the present invention is a thick film dielectric electroluminescent device comprising; a thin fine-grained rare earth metal activated zinc sulfide phosphor layer; and an interface modifying layer adjacent one or both sides of said phosphor layer. According to yet another aspect of the present invention is a method for making a fine grained rare earth metal activated zinc sulfide phosphor film, said method comprising; depositing said film onto a substrate using a sputtering process in an atmosphere comprising argon at a working pressure in the range of about 0.5 to 5×10 −2 torr and an oxygen partial pressure of less than about 0.05 of the working pressure, said film substrate maintained at a temperature between ambient temperature and about 300° C., at a deposition rate in the range of about 5 to 100 Angstroms per second, wherein the atomic ratio of the rare earth metal to zinc in the source material is in the range of about 0.5 to 2 percent. In aspects of the method, the oxygen partial pressure is preferably less than about 0.02 percent of the working pressure; the film substrate is maintained at a temperature of about between ambient and 200° C.; the working pressure is in the range of about 1 to 3×10 −2 torr, the deposition rate is in the range of about 5 to 100 Angstroms per second, more preferably in the range of about 5 to 50 Angstroms per second and more preferably in the range of about 10 to 30 Angstroms per second; and the atomic ratio of the rare earth element to zinc in the source material is in the range of about 0.5 to 2 percent. According to still a further aspect of the present invention is a method for stabilizing a fine grained rare earth metal activated zinc sulfide phosphor, said method comprising; providing an interface modifying layer adjacent one or both sides of said phosphor. According to yet another aspect of the invention is a method for stabilizing a fine grained rare earth metal activated zinc sulfide phosphor within a thick film dielectric electroluminescent device, said method comprising; providing a structure and/or substance to minimize or prevent reaction of the fine grained phosphor with oxygen, wherein said structure or substance comprises one or more of; i) interface modifying layers on one or both sides of the phosphor film to improve the stability of the interface between the phosphor film and the rest of the device; ii) a hermetic enclosure for the electroluminescent device; and iii) an oxygen getter incorporated into the device. Other features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples while indicating 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 said detailed description. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description given herein and from the accompanying drawings, which are given by way of illustration only and do not limit the intended scope of the invention. FIG. 1 shows a schematic drawing of the cross section of a thick dielectric electroluminescent device showing the position of silicon nitride layers of the present invention. FIG. 2 are graphs showing the luminance versus cumulative operating time for electroluminescent devices having an electron beam-deposited terbium activated zinc sulfide phosphor subject to different annealing conditions. FIG. 3 is a scanning electron micrograph of a cross section of an electron beam evaporated terbium activated zinc sulfide phosphor film in an electroluminescent device. FIG. 4 is a graph showing the luminance versus cumulative operating time for an electroluminescent device having a fine-grained sputtered terbium activated zinc sulfide phosphor FIG. 5 is a scanning electron micrograph of a cross section of a fine-grained sputtered terbium activated zinc sulfide phosphor film in an electroluminescent device. FIG. 6 is a graph comparing the luminance versus cumulative operating time for an electroluminescent device having a fine-grained sputtered terbium activated phosphor film in contact with an undoped zinc sulfide layer against that of a similar device without the undoped zinc sulfide layer. FIG. 7 is a graph comparing the luminance versus cumulative operating time for an electroluminescent device having a fine grained sputtered terbium activated phosphor film doped with oxygen against that of a similar device that was not doped with oxygen. FIG. 8 is a graph comparing the luminance versus cumulative operating time for an electroluminescent device having a fine-grained sputtered terbium activated phosphor film in contact with a silicon nitride layer against that of a similar device without the silicon nitride layer. FIG. 9 is a graph comparing the luminance versus cumulative operating time for an electroluminescent device having a fine-grained sputtered terbium activated phosphor film in contact with an alumina layer deposited using atomic layer chemical vapour deposition. DETAILED DESCRIPTION OF THE INVENTION The present invention is a fine-grained zinc sulfide thin film phosphor layer in a thick film electroluminescent device where additionally a structure and/or substance is provided to minimize or prevent reaction of the fine grained phosphor with oxygen. The structure or substance may be selected from one or more of: interface modifying layers on one or both sides of the phosphor film to improve the stability of the interface between the phosphor film and the rest of the device; a hermetic enclosure for the electroluminescent device; and an oxygen getter incorporated into the device. It is understood by one of skill in the art that the fine grained zinc sulfide phosphor of the invention may be incorporated into an electroluminescent device additionally having one or all of the aforementioned structures or devices. In one preferred aspect, the fine grained thin film zinc sulfide phosphor film is in contact at one or both surfaces with an interface modifying layer that improves the electrical and chemical stability of the phosphor film and its interface with the rest of the electroluminescent device. The novel combination of fine grained phosphor with a preferred morphology and with a preferred crystal structure with one or more layers of an interface modifying layer adjacent the phosphor, acts to stabilize the phosphor from degradation and provide enhanced luminance and longer operational life of the phosphor within an electroluminescent device. The present invention is particularly applicable to electroluminescent devices employing a thick dielectric layer having a high dielectric constant dielectric layer wherein the thick dielectric material is a composite material comprising two or more oxide compounds that may evolve chemical species that are deleterious to phosphor performance in response to thermal processing or device operation and wherein the surface of the thick dielectric is rough on the scale of the phosphor thickness resulting in cracks or pinholes through the device structure and contains voids that may contain or absorb such species, thus contributing to a loss of luminance and operating efficiency over the operating life of the device. FIG. 1 shows a schematic drawing of the cross section of an electroluminescent device of the present invention generally indicated by reference numeral 10 . The device 10 has a substrate 12 with a metal conductor layer 14 (ie. gold), a thick film dielectric layer 16 (i.e. PMT-PT) and a smoothing layer 18 (i.e. lead zirconate titanate) thereon. A variety of substrates may be used, as will be understood by persons skilled in the art. The preferred substrate is a substrate that is opaque in the visible and infrared regions of the electromagnetic spectrum. In particular, the substrate is a thick film dielectric layer on a ceramic substrate. Examples of such substrates include alumina, and metal ceramic composites. An interface modifying layer 18 is shown to be present adjacent the phosphor layer 20 . While the interface modifying layer 18 is shown on both sides of the phosphor, it is understood that only one such layer either above or below the phosphor may be used. A thin film dielectric layer 22 and then an ITO transport electrode 24 are present above the phosphor. A hermetic enclosure 26 is shown disposed over the laminated structure which is enclosed by a sealing bead 28 . The interface modifying layer helps to minimize migration of oxygen into the phosphor material during device operation to avoid performance degradation. The interface modifying layer, in addition to inhibiting the migration of oxygen, helps to minimize migration of water or other deleterious chemical species originating from the external environment into the phosphor to cause a reduction in luminance. Similarly, a hermetic enclosure and oxygen getter both act to minimize exposure of the phosphor material to oxygen. The present invention is particularly directed towards improving the luminosity and operating life of rare earth-activated zinc sulfide phosphor materials, or zinc sulfide phosphors doped with another activator whose radiative efficiency can be improved by reducing the grain size of the host crystal lattice. While not being bound to any particular theory, the increase in phosphor stability and luminance may be related to an increase in the radiative transition probability for the activator species in question due to a change in its local environment within the host lattice, for example by a slight shift in the atomic levels localized on the activator atom relative to the electronic band gap of the zinc sulfide host lattice. If the energy difference between one or other of these electronic energy levels and the electron states in the top of the valence band or bottom of the conduction band is reduced by sufficiently reducing the grain size such that the electronic band structure deviates to a degree from that for bulk zinc sulfide, then spectroscopic selection rules that would normally prevent or nearly prevent the optical transition in question may be partially removed, thus increasing the radiative transition probability. This may in turn decrease a tendency for non-radiative relaxation of the activator species (such that light would not be emitted during the relaxation process). This model is supported by the experimental observation that the radiative decay time for photoexcitation of terbium as an activator species is substantially reduced if the host grain size is reduced to about 50 nm. Some activator species such as manganese in zinc sulfide are relatively unaffected by a decrease in the crystal grain size of the host material, and this may have to do with the positioning of the manganese electron states with respect to the zinc sulfide band gap. Also activator species typified by manganese may be relatively unaffected by the substitution of oxygen of sulfur in the immediate environment of the host lattice. The pronounced reduction in the luminance of terbium activated zinc sulfide with the substitution of oxygen for sulfur in the host lattice is possibly due to the high affinity of terbium for oxygen. Sulfur can be displaced by oxygen in the zinc sulfide host material. Such reactions are expected to be enhanced if the grain size is small. The zinc sulfide phosphors for the invention can be represented by the formula ZnS:RE where RE is a rare earth metal selected from the group consisting of terbium and europium. Terbium is most preferred for use in the invention. The atomic ratio of terbium or europium to zinc is preferably in the range of about 0.005 to about 0.02 and more preferably in the range of about 0.01 to 0.02. The zinc sulfide phosphors of the invention are fine grained rare earth-activated zinc sulfide phosphor films wherein the crystal structure of the zinc sulfide comprises the zincblende (sphalerite) crystal structure with the ( 111 ) crystallographic direction substantially aligned in a direction perpendicular to the plane of the film and wherein an interface modifying film is provided in contact with one or both surfaces of the film. The fine grained phosphor is preferably deposited using a sputtering process in an atmosphere comprising argon or another inert gas and optionally containing a minor concentration of hydrogen sulfide or another sulfur bearing vapour to minimize oxygen incorporation into the phosphorfilm. The crystal grains of the zinc sulfide phosphor are columnar in shape with the long dimension of the columns extending substantially across the thickness of the phosphor film in a direction perpendicular to the film and where the width of the columnar grains is less than about 50 nm, and wherein the phosphor film is in contact at one or both of its surfaces with an interface modifying layer for the purpose of minimizing performance degradation of the phosphor material during device operation. The grain size is defined as the dimension in a direction perpendicular to the column axis when the grains have a columnar shape. It is understood by those of skill in the art that the crystal grain dimension can be of any size up to about 50 nm and any ranges thereof, such as from but not limited to about 20 nm to about 50 nm, about 30 nm to about 50 nm and about 40 nm to about 50 nm. The thickness of the zinc phosphor layer is about 0.5 to about 1.0 μm. The phosphor of the present invention may be deposited onto a suitable substrate by a variety of known methods such as for example, sputtering, electron beam deposition and chemical vapour deposition. Sputtering is the preferred method to deposit the fine grained phosphor. Sputtering is conducted in an atmosphere comprising argon at a working pressure in the range of about 0.5 to 5×10 −2 torr and an oxygen partial pressure of less than about 0.05 percent of the working pressure. The film substrate is maintained at a temperature between ambient temperature and about 300° C. at a deposition rate in the range of about 5 to 100 Angstroms per second. The atomic ratio of the rare earth metal to zinc in the source material is about 0.5 to about 2 percent to provide the desired ratio in the deposited film in the range of about 0.005 to 0.02 and preferably in the range of about 0.01 to 0.02. It is understood by one of skill in the art that in aspects of the method, the oxygen partial pressure is preferably less than about 0.02 percent of the working pressure; the working pressure is in the range of about 1 to 3×10 −2 torr, the film substrate is maintained at a temperature of about between ambient and 200® C.; the deposition rate is in the range of about 15 to 50 Angstroms per second, more preferably 20 to 30 Angstroms per second; and the atomic ratio of the rare earth element to zinc in the source material in the range of about 0.8 to 1.2 percent such to provide a deposited film with an atomic ratio of rare earth element to zinc in the range of 0.005 to 0.02. The provision of a fine grained and defined crystal structure for the zinc sulfide phosphor is dependent on a variety of conditions of the deposition process such as for example: substrate nature, substrate temperature, deposition rate, type and concentration of dopant, pressure and composition of vacuum environment. In one aspect of the invention the rate at which oxygen can diffuse within the phosphor layer is limited by minimizing the concentration of sulfur vacancies in the zinc sulfide phosphor material and minimizing the oxygen concentration in the phosphor layer after fabrication of the electroluminescent device. A means to limit the oxygen and sulfur vacancy concentration is to deposit the phosphor layer in a low-pressure sulfur-containing atmosphere but at a pressure sufficient to ensure that the deposited phosphor material is not sulfur-deficient. Conditions to ensure sulfur sufficiency are well known in the art. Further, one of skill in the art could readily examine the deposited phosphor film and confirm by methods such as x-ray diffraction analysis that the film was in fact fine grained in accordance with the present invention. The effect of oxygen in decreasing the luminance of terbium activated zinc sulfide thin phosphor films has been demonstrated by comparing the performance of films sputtered in an argon atmosphere to that of films sputtered in an atmosphere comprising 0.1% oxygen in argon. The luminance of the latter films in thick dielectric electroluminescent devices was shown to be substantially, lower than that of the former films. The interface modifying layer(s) of the invention can comprise a variety of materials such as for example pure zinc sulfide, hydroxyl ion free alumina, aluminum nitride, silicon nitride and aluminum oxide that has been deposited using atomic layer epitaxy wherein the hydroxyl ions contained within the oxide layer is maintained at a concentration sufficiently low that it does not contribute to phosphor degradation. Preferred materials for use as an interface modifying layer are pure undoped zinc sulfide and silicon nitride. The thickness of the modifying layer or layers is chosen to be sufficient to prevent oxygen incorporation into the phosphor film but not too thick that the voltage drop across the modifying and phosphor contributes excessively to an increased operation voltage for the display. If the modifying layer is too thin, it may not be continuous and therefore may not prevent oxygen incorporation into the phosphor layer. Further, diffusion of oxygen through the film along grain boundaries is faster if the film is thinner. Generally, if the relative dielectric constant of the modifying layer is in the range of about 7 to 10, a thickness in the range of about 40 to 60 nm is suitable. One skilled in the art may readily optimize the thickness by achieving a practical trade-off between the inhibiting reaction of oxygen with the phosphor and minimizing the operating voltage for the device. In one aspect of the invention, sputtering is the preferred method for deposition of a silicon nitride interface modifying layer phosphor. The deposition rate is controlled by adjusting the rf power to the target. The deposition rate being adjusted to provide a dense non-porous coating to provide an effective oxygen barrier at the desired thickness. Typically a deposition rate in the range of about 4 to 6 Angstroms per second is suitable. The temperature of the substrate during deposition is maintained close to ambient temperature up to about 200° C. In the case of silicon nitride (that does not contain oxygen), the film composition of the silicon nitride should be controlled in order that it adhere well to the phosphor layer. Specifically, the film should not contain nitrogen beyond the stoichiometric ratio for Si 3 N 4 . Excess nitrogen has been found to cause internal stress to accumulate within the film leading to delamination. It has been found that if the reactive sputtering is carried out using a silicon nitride target in a low pressure nitrogen atmosphere, the composition of the film can be controlled so that the film comprises a composite film comprising stoichiometric silicon nitride and elemental silicon. Provided that the silicon content is maintained at a suitably low level, the electrical resistivity of the silicon nitride film will be maintained at a suitably high value, the chemical reactivity will be suitably low and the internal stress in the film will be sufficiently low to prevent delamination of the silicon nitride film from the phosphor and other adjacent layers. The required composition for a sputtered silicon nitride film can be achieved provided that the ratio of argon to nitrogen is within the range of about 6:1 to 2:1 and the working pressure is maintained within the range of about 8×10 −4 torr to about 6×10 −3 torr. If the ratio of argon to nitrogen is too low, the deposited film will have high internal stress and may delaminate from adjacent layers. If the ratio is too high the deposited film may be chemically reactive and have an unacceptably high electrical conductivity. These undesirable properties will arise if the silicon phase is in sufficient concentration to form a continuous silicon network through the composite film and is not encapsulated by the silicon nitride phase to prevent chemical reaction of the silicon with oxygen or other reactive species in the immediate environment. The nitrogen content must be optimized within a preferred range by appropriate control over the deposition and subsequent thermal treatment of the silicon nitride film in a manner that is compatible, with the rest of the display structure upon which it is deposited. Typically it is found that vacuum deposition from a silicon nitride target provides satisfactory results provides that the deposition atmosphere comprises an inert atmosphere with a sufficient concentration nitrogen present to avoid silicon precipitation, but not so high as to allow excessive nitrogen to be incorporated into the film. Sputtering has been found to be particularly effective as a deposition means. Hermetic enclosures may comprise an optically transparent cover plate disposed over the laminated structure comprising the fine grained phosphor layer deposited onto a substrate. A sealing bead is provided between the substrate and cover plate beyond the perimeter of the laminated structure. The sealing bead may comprise a glass frit or polymeric material. Alternatively, a hermetic enclosure may be an oxygen-impermeable sealing layer extending over and beyond the perimeter of the laminated structure to prevent the phosphor to oxygen exposure. Suitable oxygen-impermeable materials are known to those of skill in the art and may include but are not limited to glass and glass frit compositions. Getter materials, in particular, oxygen getters may be used to remove traces of oxygen in the electroluminescent display. Suitable getter materials for use in the invention are known to those of skill in the art and include but are not limited to titanium and barium. It is preferred that the getter material not be directly incorporated or in contact with the phosphor layer. The present invention is suited for use in an electroluminescent display or device as described for example in Applicant's WO 00/70917 (the disclosure of which is incorporated herein by reference). Such an electroluminescent device has a substrate on which is located row electrodes. A thick film dielectric is provided with a thin film dielectric thereon. Thin film dielectric is provided as pixel columns. The pixel columns cortain phosphors to provide the three basic colors viz. red, green and blue. In an alternate embodiment, a common thin film dielectric may be deposited over all of the pixels at one time rather than separately deposited dielectric layers over each pixel. A variety of substrates may be used, as will be understood by persons skilled in the art. In particular, the substrate is a rigid refractory sheet that in one aspect has deposited thereon an electrically conductive film with a thick dielectric layer deposited on the conductive film. Examples of suitable refractory sheet materials include but are not limited to ceramics such as alumina, metal ceramic composites, glass ceramic materials and high temperature glass materials. Suitable electrically conductive films are known to those of skill in the art such as, but not limited to, gold and silver alloy. The thick dielectric layer comprises ferroelectric material. The thick dielectric layer may also comprise one or more thin film dielectric layers thereon. The above disclosure generally describes the present invention. A more complete understanding can be obtained by reference to the following specific Examples. These Examples are described solely for purposes of illustration and are not intended to limit the scope of the invention. Changes in form and substitution of equivalents are contemplated as circumstances may suggest or render expedient. Although specific terms have been employed herein, such terms are intended in a descriptive sense and not for purposes of limitation. EXAMPLE 1 Three thick dielectric electroluminescent devices incorporating thin film phosphor layers comprising fine-grained zinc sulfide activated with terbium were constructed. The thick film substrate was comprised of a 5 cm by 5 cm alumina substrate having a thickness of 0.1 cm. A gold electrode was deposited on the substrate, followed with a thick film high dielectric constant dielectric layer in accordance with the methods exemplified in Applicant's co-pending international application PCT CA00/00561 filed May 12, 2000 (the entirety of which is incorporated herein by reference). A thin film dielectric layer consisting of barium titanate, with a thickness of about 100-200 nm, was deposited on top of the thick film dielectric layer using the sol gel technique described in Applicant's co-pending U.S. patent application Ser. No. 09/761,971 filed Jan. 17, 2001 (the entirety of which is incorporated herein by reference). A zinc sulfide phosphor film activated with about 2 atomic percent terbium added to the source material as a mixture of terbium fluoride and terbium oxide as Tb 4 O 7 was electron-beam evaporated on top of the barium titanate layer. The deposition was carried out in a chamber initially evacuated to a pressure of 5×10 −6 torr and into which hydrogen sulfide was injected at 0 to 35 sccm to maintain a hydrogen sulfide pressure of 1 to 10×10 −5 torr during the deposition. The substrate was at a temperature in the range of 100° C. to 200° C. during the deposition. The growth rate of the film was 20 to 50 Angstroms per second and the film thickness was in the range of 0.9 to 1.1 micrometers. Next a 50 nm thick alumina layer and an indium tin oxide upper conductor film were deposited on the phosphor layer according to the methods of Applicant's co-pending international application PCT CA00/00561 (the entirety of which is incorporated herein by reference) and wherein one completed device was annealed in air at 550° C., one was annealed under nitrogen at 550° C., and the third was not annealed following deposition of the indium tin oxide and prior to testing. The electroluminescence of the completed devices was measured by applying a 240 Hz alternating polarity square wave voltage waveform of amplitude 60 volts about the optical threshold voltage for the device. The luminance data is shown in FIG. 2 . The measured luminance can be seen from the figure to be in the range of about 300 to 400 candelas per square meter, slowly decreasing to about 250 to 350 candelas per square meter after about 5000 hours testing. A scanning electron micrograph was obtained of a cross section of the deposited phosphor film, as shown in FIG. 3 . The majority of the crystal grains can be seen to be in the size range of 50 to 150 nm with an aspect ratio (length to width ratio) in the range of about 1:1 to 5:1. Also visible in the micrograph are the alumina layer and indium tin oxide layer above the phosphor film and a portion of the underlying dielectric layer upon which the phosphor was deposited. Chemical analysis of the film by energy dispersive x-ray analysis (EDX) showed that it was essentially stoichiometric with an atomic ratio of sulfur to zinc close to 1. EXAMPLE 2 Two electroluminescent devices were constructed similar to that of example 1, but with a fine-grained terbium activated zinc sulfide phosphor film deposited using an rf sputtering process rather than electron beam evaporation. The film was sputtered in a chamber initially evacuated to a base pressure of 8×10 −7 torr and then filled with argon controlled to a pressure of 2.5×10 −2 torr during the sputtering process. The sputtering target was a rectangular solid of dimensions 38 cm long by 12 cm wide by 0.7 cm thick with a composition similar to that of the electron beam pellet. The film was deposited at a rate of 20 Angstroms per second to a thickness in the range of 650 to 800 nm using an rf power of 2.6 watts per cm 2 . The devices were tested under similar conditions to those of example 1 except that the aging test was carried out at 240 Hz during the first 300 hours and then switched to 1.2 kHz to accelerate the test. The results with the time scale multiplied by 5 beyond 300 hours (the ratio of 1.2 kHz to 240 Hz) and the luminance divided by the same factor beyond 300 hours in FIG. 4 . As can be seen from this figure, the initial luminance was about 750 candelas per square meter, but decreased in an approximately linear fashion to about 400 candelas per square meter after the equivalent of about 7000 hours of testing. This example shows that the initial luminance was substantially improved over that for the electron beam deposited phosphor having a larger grain size, but, unlike the phosphors with larger grain size, the luminance decreased significantly with increasing operating time. A scanning electron micrograph was obtained of a cross section of a similar device. The scanning electron micrograph is shown in FIG. 5 . It shows that the crystal grains of the phosphor film are substantially aligned in a direction perpendicular to the plane of the film and extend substantially across the approximate 700 nm thickness of the film. The width of the grains is mostly in the range of 20 to 50 nm. Further, x-ray diffraction analysis of the film showed the grains to consist of the zincblende crystal structure with the (111) crystallographic direction substantially perpendicular to the plane of the film. However, the film was found to be deficient in sulfur, with an atomic ratio of sulfur to zinc determined from EDX measurement of about 0.9 and with a portion of the anion deficiency made up with oxygen. EXAMPLE 3 An electroluminescent device was constructed similar to that of example 2, but with an interface modifying layer comprising a 50 nm thick undoped zinc sulfide layer deposited using electron beam evaporation on top of the phosphor layer. The luminance versus operating time in an accelerated aging test where the voltage pulse frequency was 240 Hz for the first 300 hours and 1.2 KHz thereafter is shown in FIG. 6 , against similar data for another device without the undoped zinc sulfide. The luminance was converted to an equivalent luminance at 240 Hz, as in the previous examples. It can be seen from this figure that the initial luminance of the two devices is similar, but the rate of decrease of the luminance of the one with the undoped zinc sulfide layer is significantly lower. This example shows the benefit of the undoped essentially pure zinc sulfide layer in stabilizing the luminance of the fine-grained terbium activated zinc sulfide phosphor layer. EXAMPLE 4 Four electroluminescent devices similar to those of example 2, two of which had 0.1 percent oxygen added to the: argon used to maintain the atmosphere for phosphor film sputtering were constructed and tested. The comparative luminance data is shown in FIG. 7 . As can be seen from this figure, the addition of oxygen resulted in a film with significantly reduced luminance. EXAMPLE 5 Two electroluminescent devices similar to those of example 2 were constructed, except that a 50 nm thick silicon nitride layer was sputtered onto the phosphor layer of one of the devices prior to deposition of an upper alumina dielectric layer and the indium tin oxide electrode. To deposit the silicon nitride layer a Si 3 N 4 sputtering target was employed and the sputtering atmosphere was an argon-nitrogen mixture with a ratio of argon to nitrogen of 2.3. The working pressure for sputtering was 2×10 3 torr. The argon flow rate into the sputtering chamber, during the sputtering operation was about 7 sccm. The deposition rate for the film was 5 Angstroms per second. The luminance of the devices was measured as a function of operating time in an accelerated test at 1200 Hz with a voltage 60 volts above the initial threshold voltage. The comparative luminance data, converted to luminance at 240 hz, is shown in FIG. 8 . As with the insertion of an undoped zinc sulfide on top of the phosphor film, the silicon nitride layer had the effect of stabilizing the luminance of the device as it was operated. EXAMPLE 6 Two electroluminescent devices similar to those of example 3 were constructed except that a 30 nm thick alumina layer was deposited using atomic layer epitaxy onto the phosphor layer. The atomic layer chemical vapour deposition (ALCVD) was carried out using tetramethyl aluminum and water as precursor reagents with the deposition substrate held at a temperature of 290° C. The use of ALCVD ensured that the deposited alumina layer was conformal to the phosphor surface and had a minimal density of pinholes or other defects that may allow oxygen infusion into the phosphor layer It also minimized the hydroxyl content of the alumina layer. The luminance of the devices was measured as a function of operating time at 240 Hz. The luminance at 60 volts above the threshold voltage stablized at about 1050 candelas per square meter and remained at level for in excess of 500 hours. The luminance data is shown in FIG. 9, again showing the stabilizing effect of the protective layer. EXAMPLE 7 Four devices were constructed similar to those in example 2, except that the working pressure and flow or the argon component of the working gas were varied as identified in table 1 below. The luminance at 60 volts above the threshold voltage at a frequency of 240 Hz. TABLE 1 Device Number Working Pressure Argon Flow Luminance 1  8 × 10 −3 torr  52 sccm 1315 cd/m 2 2  8 × 10 −3 torr 160 sccm 1695 cd/m 2 3 15 × 10 −3 torr 100 sccm 2320 cd/m 2 4 25 × 10 −3 torr 172 sccm 2215 cd/m 2 The phosphor grain structure of the four devices was examined by scanning electron microscopy of cross sections of the phosphor film. It was noted device #1 had a grain diameter of approximately 50 nm and did not show columnar grain shapes. Device #2 also had a grain diameter of about 50 nm and a measure of columnar structure. Devices #3 and #4 had clearly columnar grains and grain sizes of approximately 40 nm and 30 nm, respectively. This example demonstrates improved luminance associated with phosphor grain sizes of less than 50 nm achieved as the working pressure is increased above 8×10 −3 torr. It also demonstrates a weaker trend to higher luminance as the working gas flow rate is increased. This latter effect is thought to be due to more efficient purging of oxygen from the process gas at higher flow rates. Although preferred embodiments of the invention have been described herein in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.

An improved fine grained zinc sulfide phosphor is provided for use in ac electroluminescent displays. The fine-grained zinc sulfide phosphor film exhibits improved luminance and may be used in conjunction with a structure or substance to minimize or prevent reaction of the fine grained phosphor with oxygen. The invention is particularly applicable to zinc sulfide phosphors used in electroluminescent displays that employ thick dielectric layers subject to high processing temperatures to form and activate the phosphor films.

CROSS-REFERENCES TO RELATED APPLICATIONS This application is a Continuation Application of and claims priority to U.S. Pat. application No. 11/385,278, filed on Mar. 20, 2006, titled “IMAGE PROCESSING SYSTEM FOR SKIN DETECTION AND LOCALIZATION,” by Dempski, et al. BACKGROUND OF THE INVENTION 1. Technical Field The invention relates to image processing. In particular, the invention relates to skin detection and localization in an image. 2. Related Art Continuous and rapid developments in imaging technology have produced correspondingly greater demands on image processing systems. Extensive improvements in imaging technology have given rise to larger and higher resolution image data sets, which in turn require faster and more efficient processing systems to maintain an acceptable level of system responsiveness. At the same time, an increasing number of industries, ranging from security to medicine to manufacturing, have turned to image processing to keep pace with the demands of modern marketplaces. For example, image processing to detect skin is an important first step in many security industry applications, including facial recognition and motion tracking. In the case of facial recognition, before a security application can compare a face to the faces in a database, an image processing system must first determine whether or not a video or static image even contains skin. If the image does contain skin, the image processing system must determine where in that image the skin is located and whether it is facial skin. Furthermore, it is often desirable to perform such skin and face detection in real-time to analyze, for example, a video stream running at 30 frames-per-second from a security camera. In the past, a general purpose central processing unit (CPU) in an image processing system performed skin detection. Alternatively, costly and highly customized image processing hardware was sometimes designed and built to specifically detect skin in images. However, annual incremental advancements in general purpose CPU architectures do not directly correlate with an increased ability to perform specialized image processing functions such as skin detection and localization. Furthermore, the resources which a CPU may devote to skin detection are limited because the CPU must also execute other demanding general purpose system applications (e.g., word processors, spreadsheets, and computer aided design programs). Therefore, past implementations of skin detection and localization were limited to two relatively unsatisfactory options: reduced speed and efficiency of processing performed by a general purpose CPU, or the increased costs and complexity of highly customized hardware. For example, designing and manufacturing highly customized hardware for skin detection to accommodate the massive rollout of security cameras throughout major cities, or the increased security screening at airports, would prove extremely costly and impractical. Yet these and other applications are limited in effectiveness without high performance image processing solutions. Therefore, a need exists for an improved processing system for skin detection and localization. SUMMARY An image processing system provides extremely fast skin detection and localization. The image processing system implements specialized processing techniques in a graphics processing unit (GPU) to perform the majority of the skin detection and localization processing. The main system processor is then free to perform other important tasks. The GPU speeds the detection and localization due to its highly optimized texture processing architecture. The image processing system thereby leads to a less expensive skin detection and localization solution, particularly compared to past systems which relied on highly customized image processing hardware. The image processing system includes a system processor, a GPU, a system memory, and a skin detection program. The GPU includes a highly optimized graphics processing architecture including a texture memory and multiple pixel shaders. The system memory initially stores a probability table and the source image in which to detect skin. The skin detection program uploads the probability table and the source image from the system memory to the texture memory in the GPU. The skin detection program then defines a render target with respect to the source image and issues a draw call to the GPU. The draw call initiates texture mapping by the pixel shaders of the source image and the probability table onto the render target. The texture mapping operation, in conjunction with a skin threshold (e.g., an alpha test threshold), determines which of the pixels rendered in the render target are considered skin pixels. In addition to determining whether skin exists in the source image, the image processing system may also locate the skin. To that end, the image processing system includes a skin location program. In one implementation, the skin location program performs a block tree search (e.g., a quad tree search) of the source image. As will be explained in more detail below, in performing the block tree search, the skin location program iteratively issues draw calls to the GPU to cause the pixel shaders to texture map the probability table onto progressively smaller render targets positioned within the source image. The skin location program stores the locations in the source image where skin pixels were found in the system memory. Other systems, methods, features and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the following claims. BRIEF DESCRIPTION OF THE DRAWINGS The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views. FIG. 1 shows an image processing system which detects and localizes skin in a source image. FIG. 2 shows an RGB color space including a plot of RGB color values for a set of skin samples. FIG. 3 shows a Y-Cb-Cr color space including a plot of Y-Cb-Cr color values for a set of skin samples, and a two-dimensional Cb-Cr color space including a plot of the skin samples with respect to only the Cb-Cr values. FIG. 4 shows a probability plot obtained from the Cb-Cr color space shown in FIG. 3 . FIG. 5 shows the acts which a setup program may take to setup a GPU for skin detection or localization. FIG. 6 shows the acts which a skin detection program may take to determine whether skin exists in a source image. FIG. 7 shows the acts which a skin location program may take to locate skin within a source image. FIG. 8 shows the acts which a pixel shader control program may take in a GPU for skin detection and localization to identify skin pixels in a source image. FIG. 9 shows a portion of a source image including skin pixels, and progressively smaller render targets. FIG. 10 shows a portion of a source image including skin pixels, and progressively smaller render targets. FIG. 11 shows a skin localization performance graph of an image processing system, in comparison to performing localization entirely on a general purpose CPU. FIG. 12 shows a skin localization performance graph of an image processing system that saves the render target, in comparison to the performance of a general CPU. FIG. 13 shows a skin localization performance graph of an image processing system 100 under the assumption that the image processing system does not save the render target, in comparison to the performance of a general purpose CPU. FIG. 14 shows an image processing system including a communication interface connected to a network. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The elements illustrated in the Figures function as explained in more detail below. Before setting forth the detailed explanation, however, it is noted that all of the discussion below, regardless of the particular implementation being described, is exemplary in nature, rather than limiting. For example, although selected aspects, features, or components of the implementations are depicted as being stored in memories, all or part of the systems and methods consistent with the image processing system may be stored on, distributed across, or read from other machine-readable media, for example, secondary storage devices such as hard disks, floppy disks, and CD-ROMs; a signal received from a network; or other forms of ROM or RAM either currently known or later developed. Furthermore, although specific components of the image processing system will be described, methods, systems, and articles of manufacture consistent with the systems may include additional or different components. For example, a system processor may be implemented as a microprocessor, microcontroller, application specific integrated circuit (ASIC), discrete logic, or a combination of other type of circuits or logic. Similarly, memories may be DRAM, SRAM, Flash or any other type of memory. Parameters (e.g., thresholds), databases, tables, and other data structures may be separately stored and managed, may be incorporated into a single memory or database, or may be logically and physically organized in many different ways. Programs may be parts of a single program, separate programs, or distributed across several memories and processors. FIG. 1 shows an image processing system 100 which provides faster than real-time skin detection and localization. The image processing system 100 includes a system processor 102 , a system memory 104 , and a GPU 106 . The GPU may be a graphics processor available from NVIDIA of Santa Clara, Calif. or ATI Research, Inc of Marlborough, Mass., as examples. As will be described in more detail below, the system processor 102 executes a setup program 108 , a skin detection program 110 , and a skin location program 112 from the system memory 104 . The system memory 104 stores a probability table 114 , a source image 116 , and an occlusion query 118 . The system memory 104 also stores a skin detection flag 120 , system parameters 122 , an occlusion result 124 , and skin locations 126 . The system parameters 122 may include a render target upper size limit 128 , a render target lower size limit 130 , and a skin threshold 132 . The memory also stores an occlusion result 124 obtained from the GPU 106 . The occlusion result 124 may provide a skin pixel count 134 . The GPU 106 includes a texture memory 136 , multiple parallel pixel shaders 138 , and a frame buffer 140 . The texture memory 136 stores a probability texture 142 and an image texture 144 . Multiple parallel pixel shaders 138 process the probability texture 142 and image texture 144 in response to draw calls from the system processor 102 . The multiple parallel pixel shaders 138 execute a pixel shader control program 148 . Alpha test circuitry 150 filters the pixels processed by the pixel shaders 138 . In particular, the alpha test circuitry 150 applies an alpha test 154 to determine whether to keep or discard texture processed pixels. The system processor 102 may establish the skin threshold 132 or other filter parameter for the alpha test 154 . The skin threshold 132 represents a probability below which texture processed pixels are not likely enough to be skin to count as skin pixels. The GPU 106 discards such pixels, but stores the pixels which pass the alpha test 154 as processed pixels 152 in the frame buffer 140 . The source image 116 may be obtained from a video stream, a digital camera, or other source. The source image 116 includes image data represented in a particular color space, such as the RGB color space. The image processing system 100 , however, may process images with image data represented in other color spaces. The image processing system 100 obtains and stores the source image 116 in the system memory 104 for processing. The system processor 102 executes the setup program 108 as a precursor to executing the skin detection program 110 and/or the skin location program 112 . The programs 112 and 114 employ the probability table 114 and source image 116 in conjunction with the GPU 106 to rapidly detect and/or locate skin in the source image 116 . The setup program 108 provides the probability table 114 and the source image 116 to the GPU 106 in preparation for texture mapping operations. The image processing system 100 stores a probability table 114 constructed based on an analysis of images containing skin. The probability table 114 stores the probability that, for any particular pixel expressed in the color coordinate index (e.g., Cb-Cr) of the probability table 114 , the pixel is a skin pixel. Each possible value of Cb and Cr defines a color location in the probability table 114 at which a skin probability is stored. The probability table 114 may be pre-established in the system 100 , or the image processing system 100 may obtain the probability table 114 from an external source, such as the sources described and shown with reference to FIG. 14 . The system processor 102 may dynamically change the probability table 114 during processing to adapt the skin detection and location to any particular probability criteria. FIG. 2 shows a plot 200 of RGB color values for a set of known skin samples 202 along a Red axis 204 , a Green axis 206 , and a Blue axis 208 . The RGB plot 202 exhibits a significant smear of the skin samples throughout the RGB color space. The variance along each axis 204 , 206 , and 208 makes distinguishing between skin and non-skin pixels difficult in the RGB color space. When the RGB color values are expressed or converted to the Y-Cb-Cr color space, however, the skin pixels localize, pointing to a clearer differentiation between skin and non-skin pixels. FIG. 3 shows a plot 300 of Y-Cb-Cr color values for the set of skin samples 202 , and a two-dimensional plot 302 of the skin samples 202 with respect to only the Cb-Cr values. The Y-Cb-Cr plot 300 demonstrates tight clustering of the skin samples 202 along the Cb and Cr axes 304 and 306 . The Y axis 308 , which represents luminance, exhibits the largest amount of variance within the Y-Cb-Cr plot 300 of the skin samples. Variation in the luminance value is largely imperceptible to the human eye. Dropping the luminance value results in the two dimensional Cb-Cr plot 302 of the skin samples 202 . The skin samples 202 tend to cluster together with a small amount of variance in the Cb-Cr color space. FIG. 4 shows a probability table 400 obtained from the two dimensional Cb-Cr color space 302 shown in FIG. 3 . The probability table 400 is setup along a color coordinate index formed from the Cb and Cr (X and Z) axes 402 and 404 . Each index location defines a possible color in the Cb-Cr color space. The probability table 400 establishes a skin probability (e.g., the skin probability 408 ) along the Y axis 406 at each color location. The probability table 400 may be constructed by binning the Cb-Cr color values of the skin sample set 202 into a 255×255 table, represented by the X and Z axes 402 and 404 . The skin probability represented by the Y axis may be determined by dividing each binned value by the total number of skin samples. The clustered nature of the skin samples 202 in the Cb-Cr color model results in the relatively large skin probability 408 shown in the probability table 400 . Returning to FIG. 1 , the setup program 108 uploads the probability table 114 and source image 116 to the GPU 106 . The GPU 106 stores the probability table 114 as the probability texture 142 and stores the source image 116 as the image texture 144 in the texture memory 136 . The setup program 108 may also determine the alpha parameters (e.g., the skin threshold 132 ) for the alpha test circuitry 150 and upload the parameters to the alpha test circuitry 150 in the GPU 106 . The alpha test circuitry 150 compares the skin threshold 132 against texture determinations made by the pixel shaders 138 to determine whether the textured pixels should be considered skin pixels. The acts performed by the setup program 108 are shown in FIG. 5 and are described in more detail below. The skin detection program 110 detects whether or not the source image 116 contains skin. The skin detection program 110 issues draw calls to initiate texture mapping in the multiple parallel pixel shaders 138 . The skin detection program 110 also issues an occlusion query 118 to the GPU 106 to determine the skin pixel count 134 . The skin pixel count 134 is the number of pixels which pass the alpha test 154 and are considered skin pixels. These pixels may also be written to the frame buffer 140 . The skin detection program 110 sets or clears the skin detection flag 120 depending on whether or not the occlusion result 124 returns a non-zero skin pixel count 134 . Accordingly, the skin detection program 110 may act as a fast filter to determine whether skin exists at all in the source image 116 . The acts taken by the skin detection program 110 are shown in FIG. 6 and are described in more detail below. The skin location program 112 locates skin in the source image 116 . In one implementation, the skin location program 112 executes a block tree search of the source image 116 to locate skin pixels. The skin location program 112 initially searches regions of the source image 116 defined by the render target upper size limit 128 . In a region where skin pixels are detected, the skin location program 112 subdivides that region and searches for pixels within those subregions. The skin location program 112 may continue subdividing and searching until the size of the subregions equals the render target lower size limit 130 . In this manner, the skin location program 112 efficiently and accurately locates skin within the source image 116 , at a resolution corresponding to the lower size limit of the render target. The skin location program 112 stores the skin locations 126 (e.g., the locations of render targets which have a non-zero skin pixel count) in the system memory 104 . The acts performed by the skin location program 112 are shown in FIG. 7 and are described in more detail below. The skin detection program 110 and skin location program 112 include instructions that issue draw calls to the GPU 106 to initiate texture mapping in the multiple parallel pixel shaders 138 . The multiple parallel pixel shaders 138 texture map the probability texture 142 and the image texture 144 onto a render target. The render target may be defined by vertices which bound the render target (e.g., upper left and lower right vertices). The programs 110 and 112 receive the occlusion result 124 arising from texture mapping the render target. The occlusion result 124 specifies the number of skin pixels which pass the alpha test applied by the alpha test circuitry 150 . The programs 110 and 112 may save the locations where skin is found (e.g., by saving the render target locations with respect to the source image 116 ). After executing the skin detection and/or location programs 112 and 114 , the image processing system 100 may report the skin pixel count 134 or skin locations 126 to other applications or may use the skin pixel count 134 or skin locations 126 for other purposes. FIG. 5 shows the acts 500 which the setup program 108 may take to setup the GPU 106 for skin detection or localization. The setup program 108 obtains the probability table 114 from the system memory 104 (Act 502 ). The setup program 108 then uploads the probability table 114 to the GPU texture memory 136 as the probability texture 142 (Act 504 ). The setup program 108 also obtains the source image 116 from the system memory 104 (Act 506 ), and uploads the source image 116 to the GPU texture memory 136 as the image texture 144 (Act 508 ). The image processing system 100 may thereby apply the speed and parallel processing capabilities of the multiple parallel pixels shaders in the GPU 106 to detect and locate skin in the source image 116 . The setup program 108 may also determine alpha parameters (Act 510 ). The alpha parameters may include the skin threshold 132 or other criteria used for the alpha test 154 in the alpha test circuitry 150 . The alpha test circuitry 150 determines whether or not a texture processed pixel qualifies as a skin pixel. As described in more detail below in reference to FIG. 14 , the setup program 108 may also determine the alpha parameter based upon values provided external systems, such as systems requesting skin detection or location in the source image 116 by the image processing system 100 . The setup program 108 establishes the alpha test 154 in the GPU 106 (Act 512 ) prior to skin detection or localization. FIG. 6 shows the acts 600 which the skin detection program 110 may take to determine whether skin exists in the source image 116 . The skin detection program 110 initiates execution of the setup program 108 (Act 602 ). As described above, the setup program 108 uploads the probability table 114 and the source image 116 to the texture memory 136 as the probability texture 142 and image texture 144 respectively. The skin detection program 110 issues the occlusion query 118 to the GPU 106 to request a skin pixel count 134 (Act 604 ). The occlusion query 118 returns the number of pixels that pass the alpha test 154 for any given render target. The skin detection program 110 also defines the initial render target (Act 606 ). To that end, the skin detection program 110 determines the size and location of the render target with respect to the source image 116 . The initial render target may be a rectangle which has the upper size limit 128 (e.g., the entire size of the source image 116 ) or may be as small as the lower size limit 130 (e.g., a single pixel). The skin detection program 110 clears the skin detection flag 120 (Act 608 ) and initiates texture mapping of the probability texture 142 and image texture 144 onto the current render target (Act 610 ). To do so, the skin detection program 110 issues a draw call to the GPU 106 to initiate texture mapping by the multiple parallel pixel shaders 138 under control of the pixel shader control program 148 . The GPU 106 determines the transparency of each pixel in the render target, performs the alpha test 154 , and returns the occlusion result 124 , including the skin pixel count 134 . The skin detection program 110 receives an occlusion result 124 which contains the skin pixel count 134 of the current render target. (Act 612 ). If the skin pixel count is non-zero, the skin detection program 110 sets the skin detection flag 120 (Act 614 ) and may save the render target location at which skin was located (Act 616 ). In other implementations, the skin detection flag 120 may be set when a threshold number of skin pixels are located (e.g., 5% or more of the image contains skin). If the skin detection program 110 will search for skin in other parts of the image, the skin detection program 110 defines a new render target (e.g., a larger render target, smaller render target, or a new location for the render target) (Act 618 ) and initiates texture mapping on the current render target (Act 610 ). FIG. 7 shows the acts which the skin location program 112 may take to locate skin within the source image 116 . Although the example below assumes the skin location program 112 locates skin throughout the source image 116 , it is noted that the skin location program 112 may instead selectively locate skin in one or more sub-portions of the source image 116 . The skin location program 112 initiates execution of the setup program 108 (Act 702 ). As described above, the setup program 108 uploads the probability table 114 and the source image 116 to the texture memory 136 as the probability texture 142 and image texture 144 respectively. The setup program 108 may also determine the alpha parameters and establish the alpha test 154 in the GPU 106 . The skin location program 112 defines the render target upper size limit 128 (Act 704 ). The skin location program 112 may define the render target upper size limit 128 as the size of the entire source image 116 , or as any subregion of the source image 116 . The skin location program 112 also defines the render target lower size limit 130 (Act 706 ). The render target lower size limit 130 determines a lower bound on the size of the render target (e.g., 64×64 pixels, 16×16 pixels, 1×1 pixel, or any other lower bound). As the render target decreases in size, the location accuracy increases. The skin location program 112 issues the occlusion query 118 to the GPU 106 (Act 708 ). The skin location program 112 sets an initial render target (Act 710 ). For example, the skin location program 112 may set the initial render target to the render target upper size limit 128 , and select a position (e.g., the upper left hand corner of the source image) for the render target. The skin location program 112 makes a draw call to the GPU 106 to initiate texture mapping of the probability texture 142 and image texture 144 onto the current render target (Act 712 ). Alpha testing in the GPU acts as a filter on the transparency values of the texture mapped pixels to determine the number of texture mapped pixels which qualify as skin pixels. The skin pixel count 134 is returned in the occlusion result 124 . When the render target is full or skin pixels or empty of skin pixels, the skin location program 112 does not subdivide the render target. When the render target is full of skin pixels, the skin location program 112 saves the render target locations as skin locations 126 (Act 718 ). The skin location program 112 may also save the contents of the render target in the memory 104 . If more of the source image remains to be processed, the skin location program 112 sets a new render target (Act 720 ) (e.g., moves the render target to a new location with respect to the source image) and again initiates texture mapping. If the render target was partially full of skin pixels, the skin location program 112 determines whether the render target has reached the lower size limit 130 . If so, the skin location program 112 saves the skin locations (Act 718 ) and determines whether more of the source image remains to be processed. Otherwise, the skin location program subdivides the render target (Act 722 ). For example, when applying a quad-tree search strategy, the skin location program 112 may sub-divide the render into four smaller render targets. A new, smaller, render target is therefore set (Act 720 ), and the skin location program 112 again initiates texture mapping. In the example above, the skin location program 112 did not subdivide a render target which was completely empty of skin pixels or full of skin pixels. In other implementations, the skin location program 112 may also be configured to process a partially filled render target as if it contained either zero skin pixels, or all skin pixels. For example, the skin location program 112 may process a render target containing between zero and a threshold number of skin pixels as if the render target contained zero skin pixels. Likewise, the skin location program 112 may process a render target containing between a given threshold of skin pixels and all skin pixels as if the render target were full of skin pixels. The skin location program 112 described above may also execute skin location using predicated draw calls. A predicated draw call used in the skin location program 112 is a draw call which instructs the GPU to draw a particular render target, and if skin is detected in that render target, to subdivide the render target into subregions and draw those subregions. Accordingly, the skin location program 112 issues one draw call to draw the render target and the four smaller render targets as opposed to issuing up to five draw calls to draw the same regions. FIG. 8 shows the acts which the pixel shader control program 148 may take in the GPU 106 for skin detection and localization to identify skin pixels in the source image 116 . The pixel shader control program 148 obtains a pixel from the image texture 144 (Act 802 ). The pixel shader control program 148 converts the pixel from the color space in which the image texture 144 exists, such as the RGB color space, to the color space in which the probability texture 142 exists, such as the Cb-Cr color space (Act 804 ). The converted pixel becomes a probability coordinate which the pixel shader control program 148 indexes into the probability texture 142 . The pixel shader control program 148 determines the skin probability for the pixel by indexing the probability coordinate into the probability texture 142 (Act 806 ). The indexed value resulting from the texture mapping described above may be an RGBA value, where A contains the probability that the pixel's Cb-Cr value is skin. The pixel shader control program 148 sets the alpha value of the output pixel to the skin probability obtained from the probability texture (Act 808 ). In this instance the RGB values may contain other data such as the type of skin the pixel contains. The resulting indexed value may also be a one value component texture containing the probability that the pixel contains skin. In these examples, the pixel shader control program 148 sets the A value as the transparency of the indexed pixel. The pixel shader control program 148 , however, may output any other component on any other axis of the probability texture 142 as the rendered pixel output value (e.g., the transparency value) for the pixel. The pixel shader control program 148 then outputs the texture mapped pixel 152 (Act 810 ), which is then subject to the alpha test to determine whether the pixel qualifies as a skin pixel. Table 1, below, shows one example of a pixel shader control program which converts RBG to Cb-Cr and in which ‘MainTexture’ refers to the image texture 144 , ‘dot’ is a dot product operation, and ‘tex2D’ refers to the probability texture 142 . TABLE 1 struct VS_OUTPUT { float4 Position : POSITION; float4 Color : COLOR; float2 TexCoords0 : TEXCOORD0; float2 TexCoords1 : TEXCOORD1; }; struct PS_OUTPUT { float4 Color : COLOR; }; sampler MainTexture : register(s0); sampler CbCrBinTexture : register(s1); PS_OUTPUT main(const VS_OUTPUT OutVertex) { PS_OUTPUT OutPixel; float2 cbcrcolors; float2 cbcrwithrange; float4 CbConverter = {−0.168736, −0.331264, 0.500, 0.00}; float4 CrConverter = {0.500, −0.418688, −0.081312, 0.00}; cbcrcolors.x = dot(CbConverter, tex2D(MainTexture, OutVertex.TexCoords0)); cbcrcolors.y = dot(CrConverter, tex2D(MainTexture, OutVertex.TexCoords0)); cbcrwithrange.y = cbcrcolors.x * 0.8784 + 0.5020; cbcrwithrange.x = cbcrcolors.y * 0.8784 + 0.5020; float4 retcolor = tex2D(CbCrBinTexture, cbcrwithrange); OutPixel.Color = retcolor.r; return OutPixel; } Table 2 shows another example of a pixel shader control program 148 in which the textured pixel is determined using a 3D direction vector to index into six 2D textures arranged into a cube map. The cube map texture construct is a set of six textures, each representing the side of a three-dimensional cube. The pixel shader control program may use any three component RGB value as a vector to point from the center of the cube to a spot on the cube wall. TABLE 2 struct VS_OUTPUT { float4 Position : POSITION; float4 Color : COLOR; float2 TexCoords0 : TEXCOORD0; float2 TexCoords1 : TEXCOORD1; }; struct PS_OUTPUT { float4 Color : COLOR; }; sampler MainTexture : register(s0); sampler CbCrBinTexture : register(s1); PS_OUTPUT main(const VS_OUTPUT OutVertex) { PS_OUTPUT OutPixel; float4 Color1 = tex2D(MainTexture, OutVertex.TexCoords0); float4 retcolor = texCUBE(CubeMapTexture, Color1); OutPixel.Color = retcolor.r; return OutPixel; } FIGS. 9 and 10 show examples of a 48×48 pixel portion of a source image 900 including skin pixels 902 , render targets 904 , 906 , 908 , and 910 , and progressively smaller render targets 1000 , 1002 , 1004 , and 1006 . FIGS. 9 and 10 illustrate steps the skin location program 112 may take to locate skin within the source image 900 . In this example, the skin location program 112 sets the render target upper size limit 128 as 48×48, and the render target lower size limit 130 as 12×12. The skin location program 112 sets the 48×48 portion of the source 900 as the initial render target. The skin location program 112 initiates texture mapping of the probability texture 142 and image texture 144 onto the initial render target 900 . The skin location program 112 determines that the initial render target 900 contains more than zero, but less than all skin pixels 902 . As a result, the skin location program 112 subdivides the initial render target 900 into four smaller 24×24 subregions 904 - 910 . The skin location program 112 sets the upper left subregion 904 as the new render target and initiates texture mapping as to the render target 904 . The skin location program 112 determines that the render target 904 contains all skin pixels 902 . The skin location program 112 stores the skin locations 126 in system memory 104 . The skin location program 112 sets the upper right subregion 906 as the new render target because the skin location program 112 has not yet processed the entire subdivided render target 900 . The skin location program 112 initiates texture mapping on the render target 906 and determines that it contains zero skin pixels 902 . The skin location program 112 moves to the lower left subregion 908 as the new render target and determines that the render target 908 also contains zero skin pixels 902 . The skin location program 112 then moves to the lower right subregion 910 as the new render target and, after initiating texture mapping on to the render target 910 , determines that the render target 910 contains more than zero, but less than all skin pixels 902 . The render target 910 , 24×24 pixels, has not reached the render target lower size limit 130 . Accordingly, the skin detection program 110 subdivides the render target 910 (in this example, into four quadrants). FIG. 10 shows the render target 910 subdivided into progressively smaller 12×12 subregions 1000 - 1006 . The skin location program 112 sets one of the progressively smaller subregions 1000 - 1006 as the new render target. In this example, the skin location program 112 sets progressively smaller subregion 1000 as the new render target. After determining that the render target 1000 contains zero skin pixels 902 , and that less than the entire previously subdivided render target 910 has been processed, the skin location program 112 sets the progressively smaller subregion 1002 as the new render target. The skin location program 112 determines that the render target 1002 contains all skin pixels 902 and stores the skin location to system memory 104 . The skin location program 112 sets progressively smaller subregion 1004 as the new render target. The skin location program 112 determines that the render target 1004 contains more than zero, but less than all skin pixels 902 . The skin location program 112 also determines that the render target 1004 size equals the render target lower size limit 130 . The skin location program 112 stores the skin location into the system memory 104 . Because less than the entire previously subdivided render target 910 has been processed, the skin location program 112 sets the progressively smaller subregion 1006 as the new render target. The skin location program 112 determines that the render target 1006 contains more than zero but less than all skin pixels 902 . The skin location program 112 stores the render target 1006 to system memory 104 instead of subdividing further because the size of the render target 1006 equals the render target lower size limit 130 . Thus, the skin location program 112 determines locations for the skin pixels 902 present in the portion of the source image 900 . FIG. 11 shows a skin localization performance graph 1100 of the image processing system 100 in comparison to performing localization entirely on a general purpose CPU. The performance graph 1100 shows performance plots 1102 - 1112 achieved using modern GPUs 106 . The performance plots 1102 , 1106 , and 1110 show system 100 performance using different GPUs where render targets are not saved. The performance plots 1106 , 1108 , and 1112 show system performance using different GPUs where render targets are save to memory 104 . As demonstrated in FIG. 11 , using the image processing system 100 to locate skin results in significantly improved performance (in some cases several hundred times faster) compared to the performance plot 1114 of skin location done on a general purpose CPU. FIG. 12 shows a skin localization performance graph 1200 of the image processing system 100 that saves the render target in comparison to the performance of a general CPU. The performance graph 1200 shows different performance plots 1202 - 1214 for the image processing system 100 when the image processing system 100 saves render targets of the following render target block levels: 8×8 blocks, plot 1202 , 16×16 blocks, plot 1204 , 32×32 blocks, plot 1206 , 64×64 blocks, plot 1208 , and 128×128 blocks, plot 1210 . The performance graph 1200 also shows the performance 1212 and the average performance 1214 of the image processing system 100 where the image processing system 100 uses the quad tree approach to locating skin. As demonstrated by the performance graph 1200 , the image processing system 100 , even when saving 8×8 blocks, performs far faster (in some cases, hundreds of times faster) than processing on a general purpose CPU. FIG. 13 shows a skin localization performance graph 1300 of the image processing system 100 under the assumption that the image processing system 100 does not save the render target, in comparison to the performance of a general purpose CPU. The performance of the following render target block levels are charted: 8×8 blocks, plot 1302 ; 16×16 blocks, plot 1304 ; 32×32 blocks, plot 1306 ; 64×64 blocks, plot 1308 ; and 128×128 blocks, plot 1310 . The performance graph 1300 also shows the performance 1312 and the average performance 1314 of the image processing system 100 where the image processing system 100 uses the quad tree approach to locating skin. As demonstrated by the performance graph 1300 , the image processing system 100 is far faster (typically many hundreds of times faster) than processing on a general purpose CPU. The different performance plots in FIGS. 12 and 13 illustrate that there is overhead associated not only with saving the render targets, but also with issuing draw calls to the GPU. For example, FIG. 13 (which assumes that render targets are not saved) shows that issuing draw calls for 128×128 blocks over the render target yields higher performance than executing a significant number of additional draw calls for covering the render target using 8×8 blocks. Nevertheless, the performance is still greater than that of a general purpose CPU, and includes the added benefit of very high accuracy at a block size of 8×8, without saving the render target during the initial pass. The quad tree approach yields an intermediate level of performance (which is still far greater than that of a general purpose CPU) because that approach need not further subdivide blocks which are full or empty of pixels. The quad tree approach there need not drill down to the smallest block size in many instances. FIG. 14 shows the image processing system 100 , including a communication interface 1400 connected to a network 1402 . The image processing system 100 communicates over the network 1402 with service requestors 1404 which, for example, submit source images, probability tables, and feature detection and/or location requests to the image processing system 100 . The feature detection requests may be skin detection requests, or requests to detect other characteristics in the source image, such as hazardous substances. To that end, the service requestors may provide probability tables which establish probabilities for detecting the feature of interest (e.g., a probability table which assigns probabilities to certain colors being a hazardous substance). The service requestors 1404 may be, as examples, external security, surveillance, medicine, and/or other systems which request skin detection and/or localization in the source image 116 . Alternatively or additionally, the image processing system 100 may obtain source images from the image sources 1406 . The image sources 158 may include a video feed, digital camera, or other image source. The service requestors 1404 may also provide other data to the image processing system 100 . For example, each service requestor 1404 may provide a different feature detection threshold (e.g., a skin threshold 132 ) for use in a specific application. The service requestors 1404 may also specify the render target upper size limit 128 , the render target lower size limit 130 , or other parameters. For example, where the service requestor 1404 requests highly accurate skin location in the source image 116 , the image processing system 100 may set a relatively small (e.g., 8×8, 4×4, 2×2, or 1×1) render target lower size limit 130 . When the service requestor 1404 specifies less stringent accuracy requirements, the image processing system 100 may set a larger render target lower size limit 130 . The service requestors 1404 may use the skin detection and/or location data for a variety of applications. For example, the image processing system 100 may detect and locate skin in a source image 116 as a pre-processing step for a facial recognition system. In addition to skin detection and localization, the image processing system 100 described above may be used for other image processing tasks. For example, the image processing system 100 may be configured to detect and/or locate organic compounds for use at a security station in an airport, bus terminal, government office building, or other facility. In this example, the probability table 114 may be constructed based upon an image set of organic compound samples. In another example, the image processing system 100 may be configured to detect and/or locate certain terrain, objects, or other details in satellite images. For example, using a probability table 114 based upon a set of marijuana field image samples, the image processing system 100 may detect and locate other marijuana fields in satellite or high altitude images. As another example, the image processing system 100 may be configured to detect specific tissues or other materials in medical images. While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. As one example, the render target may stay the same size during skin detection or localization (e.g., a 640×480 canvas onto which the GPU performs texture mapping), while the draw calls may specify smaller blocks within the render target. In other words, in other implementations, the render target itself need not be subdivided. Instead, the draw calls may specify portions of the render target for skin detection and localization texture processing. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.

An image processing system provides faster than real-time skin detection and localization. The system uses the highly optimized architecture of a graphics processing unit to quickly and efficiently detect and locate skin in an image. By performing skin detection and localization on the graphics processing unit, the image processing system frees the main system processor to perform other important tasks, including running general purpose applications. The speed with which the image processing system detects and localizes skin also facilitates subsequent processing steps such as face detection and motion tracking.

FIELD OF THE INVENTION [0001] The present invention relates to liquid or dried granulated milk clotting aspartic protease enzyme composition comprising added polypeptides/proteins. BACKGROUND ART [0002] Enzymatic coagulation of milk by milk-clotting enzymes, such as chymosin and pepsin, is one of the most important processes in the manufacture of cheeses. Enzymatic milk coagulation is a two-phase process: a first phase where a proteolytic enzyme, chymosin or pepsin, attacks κ-casein, resulting in a metastable state of the casein micelle structure and a second phase, where the milk subsequently coagulates and forms a coagulum. [0003] Chymosin (EC 3.4.23.4) and pepsin (EC 3.4.23.1), the milk clotting enzymes of the mammalian stomach, are aspartic proteases belonging to a broad class of peptidases. [0004] Mucorpepsin (EC 3.4.23.23) is a milk clotting enzyme derived from the fungus Rhizomucor miehei. [0005] Commercial relevant milk-clotting enzyme products are often liquid compositions and in the art is described numerous different ways to try to stabilize the milk-clotting enzyme in the product—e.g. to improve storage stability or specific activity of the enzyme. [0006] For instance, EP2333056A1 (DSM, date of filing Dec. 4, 2007) describes that formate, acetate, lactate, propionate, malate, fumarate or propanediol may increase stability of aspartic protease enzyme in a liquid composition/product. [0007] WO2012/127005A1 (DSM) describes a stable liquid chymosin composition comprising inorganic salt in a concentration of 2-100 g/kg and a preservative such as formate, acetate, lactate, propionate, malate, benzoate, sorbate or fumarate, glycol (ethanediol), propylene glycol (propanediol), glycerol, erythritol, xylitol, mannitol, sorbitol, inositol or galactitol. The highest strength of the described chymosin compositions is1500 IMCU/ml (see e.g. page 6, lines1-3). [0008] Polyethylene glycol (PEG) is a polymer of ethylene oxide—it may alternatively be termed polyoxyethylene (POE). PEG is commercially available over a wide range of molecular weights such as from 300 g/mol to 10,000,000 g/mol. [0009] DE1492060A1 (Nordmark-Werke GmbH, published in 1969) discloses a method for making a pepsin composition by adding Polyethylene glycol (PEG) with a molecular weight of 400-6000 at a concentration of 1-20 wt % (corresponds to 10,000 to 200,000 ppm). SUMMARY OF THE INVENTION [0010] A problem to be solved by the present invention is to provide a novel milk clotting aspartic protease enzyme (e.g. chymosin) composition, wherein the aspartic protease has increased physical stability and/or specific activity. [0011] The solution is based on that the present inventors have identified that by adding suitable polypeptide/protein formulations to different aspartic protease enzymes (e.g. chymosin) one significantly improves the physical stability and the specific activity of the enzyme compositions. [0012] Liquid formulations of industrial enzymes are subjected to physical forces (such as shaking) during e.g. transportation and physical stability of an enzyme composition can be tested by repeatable shaking (e.g. via inversion) a sample in a test tube having high head space to sample volume ratio. [0013] As discussed in working Examples herein—to e.g. camel chymosin (CHY-MAX® M, Chr. Hansen A/S) were added numerous different polypeptide/protein formulations and a number of these polypeptide/protein formulations significantly increased the physical stability of camel chymosin. [0014] As discussed in working Examples herein—to bovine chymosin (CHY-MAX®, Chr. Hansen A/S), camel chymosin (CHY-MAX® M, Chr. Hansen A/S) and mucorpepsin (Hannilase®, Chr. Hansen A/S) were added numerous different polypeptide/protein formulations and a number of these polypeptide/protein formulations significantly increased the specific activity of the enzyme compositions. [0015] The increase in the specific activity was most significant for the bovine and camel chymosins. [0016] As understood by the skilled person in the present context—specific activity of a milk clotting aspartic protease enzyme composition relates to activity/IMCU per total amount of milk clotting aspartic protease enzyme protein in the composition. [0017] As described in working Examples herein—addition of e.g. whey protein formulations to a purified chymosin sample gave an enzyme composition with significant higher IMCU/ml strength—i.e. a composition with higher specific activity. [0018] For instance, addition of 0.5% (w/w) of whey protein concentrate formulation WPC 80 gave around 10% increase of the strength in the camel chymosin composition as such. [0019] Without being limited to theory—it was a surprise to the present inventors that it was possible to increase the strength of e.g. a chymosin composition/product by simply adding a suitable amount of e.g. whey proteins. [0020] It is here relevant to note that casein hydrolysate did not significantly increase the physical stability and/or the specific activity. [0021] As known to the skilled person—in a casein hydrolysate has been performed a hydrolysis of casein. [0022] Without being limited to theory—it is believed that in such a casein hydrolysate formulation a significant amount of the polypeptides are of less than 10 amino acids. [0023] Said in other words and without being limited to theory—it is believed that the herein relevant increased physical stability and specific activity effects are obtained when there are used polypeptides longer than 10 amino acids. [0024] As known in the art—the term peptide may be distinguished from the term protein on the basis of size, which as an arbitrary benchmark may be understood to be approximately 50 or fewer amino acids. [0025] Said in other words, a polypeptide longer than 50 amino acids may normally in the art be understood to be a protein. [0026] Accordingly, a polypeptide longer than 50 amino acids may herein alternatively be termed a protein. [0027] As discussed in working Examples herein—the herein relevant increased/improved physical stability and/or specific activity effects were related to the amount of polypeptide/protein composition added to chymosin—where no significant positive effect was obtained if less than 0.01% (w/w) was added. [0028] Without being limited to theory—it is believed that addition of polypeptide/protein provide increased conformational stability to the chymosins and this could explain the observed increased physical stability and increased specific activity observed in working Examples herein. [0029] Without being limited to theory—it is believed that in the prior art it has not been described or suggested that addition of polypeptide/protein may increase the stability of aspartic protease milk-clotting enzymes such as e.g. chymosins—in particular it has not been described that conformational stability may be increased. [0030] Conformational stability of an enzyme is illustrated in FIG. 3 herein. [0031] As known in the art—loss of conformation equals loss of activity of the enzyme—i.e. less specific activity of the enzyme. [0032] Without being limited to theory—loss of conformation may increase denaturation/precipitation of the enzyme and thereby give less physical stability as discussed herein. [0033] As known in the art—milk clotting aspartic protease enzymes may be seen as structurally relatively similar. [0034] As known in the art—different natural wildtype milk clotting aspartic protease polypeptide sequences obtained from different mammalian or fungal species (such as e.g. bovines, camels, sheep, pigs, or mucor) are having a relatively high tertiary structural similarity. [0035] In FIG. 4 herein this is provided an alignment of herein relevant different milk clotting chymosin sequences from different mammalian species (cow, buffalo, goat, sheep, camel and pig)—as can be seen in FIG. 4 they have a close sequence relationship and are known to have a very high tertiary structural similarity. [0036] In FIG. 5 herein there is provided an alignment of herein relevant commercially available different milk clotting aspartic protease enzymes sequences from different mammalian or fungal species (camel chymosin, cow chymosin, cow pepsin, fungal mucor pepsin and fungal Endothia pepsin). [0037] It may be said that the 5 different sequences of FIG. 5 are not highly identical—but as known to the skilled person all these 5 different milk clotting aspartic protease enzymes are known to have a high tertiary structural similarity. [0038] As discussed above and shown in working Examples herein—the herein relevant improved/increased stability/activity effects have been demonstrated for bovine chymosin, camel chymosin and mucorpepsin. [0039] Without being limited to theory—it is believed that there is no significant technical reason to believe that the herein relevant improved/increased stability effect should not be relevant for milk clotting aspartic protease enzymes in general—as discussed above, they are known to have a high tertiary structural similarity and as understood by the skilled person in the present context this tertiary structural similarity makes it plausible that the herein described polymer-enzyme interaction to get improved stability would be a general class effect of the structural similar herein relevant milk clotting aspartic protease enzymes. [0040] Accordingly, a first aspect of the invention relates to a method for making a liquid milk clotting aspartic protease enzyme composition, wherein the method comprises the steps of: (a): obtaining a purified liquid milk clotting aspartic protease enzyme sample comprising: (i): a strength of from 25 IMCU/g to 30,000 IMCU/g of the sample; and (ii): wherein at least 70% of the total amounts of proteins with a size bigger than 10 kDa, determined by SDS-PAGE, in the purified sample are milk clotting aspartic protease enzyme; and (b): adding a suitable amount of a polypeptide formulation comprising polypeptides longer than 10 amino acids to the sample of step (a), wherein the polypeptides are not milk clotting aspartic protease enzymes and not enzymes that degrade the aspartic protease enzymes, to get a liquid milk clotting aspartic protease enzyme composition, wherein the composition comprises: (I): milk clotting aspartic protease enzyme at a strength of from 26 IMCU/g to 30,100 IMCU/g of the composition; and (II): the in step (b) added not milk clotting aspartic protease enzyme polypeptides longer than 10 amino acids in a concentration from 0.01% to 10% (w/w) of the composition; and wherein the strength (IMCU/g of the composition) in (I) is at least 1% higher than the strength in (i) (IMCU/g of the sample), measured after one week of storage at 5° C. [0047] It is routine work to measure the milk clotting aspartic protease enzyme strength in (i) and in (II) and thereby identify if the requirement of higher strength in (II) is fulfilled. In the present context, it is evident to the skilled person that the control sample to measure the strength in (i) after one week of storage is the sample of step (a) (i.e. without the added polypeptide formulation of step (b)). [0048] As discussed herein, numerous of polypeptide/protein formulations were tested by the present inventors (see working Examples herein) and a number of these significantly increased the specific activity of the enzyme compositions. [0049] Accordingly, based on the teaching herein and the common general knowledge of the skilled person—the skilled person may without undue burden identify a suitable preferred protein formulation to be added in a suitable amount in step (b) in order get the required increased/higher strength of the method of the first aspect. [0050] In the present context, it is evident that in step (b) of the method of the first aspect it is not preferred to add enzymes that degrade the aspartic protease enzymes and the term “not enzymes that degrade the aspartic protease enzymes” of step (b) should be understood in relation to this. [0051] The concentration in item (II) relates to the composition as such. [0052] For instance, if the weight of the composition as such is1 kg and the concentration in item (II) of the in step (b) added polypeptides is1% (w/w) then has there in step (b) been added 10 g polypeptides longer than 10 amino acids. [0053] It is routine work for the skilled person to add a suitable amount of a polypeptide formulation in step (b) in order to get a wanted concentration of the added polypeptides in accordance with item (II) of the first aspect. [0054] In FIG. 1 herein is shown SDS-PAGE data for different samples of bovine chymosin (CHY-MAX®, Chr. Hansen A/S) and mucorpepsin (Hannilase®, Chr. Hansen A/S). For both CHY-MAX® and Hannilase® are Lane 2 (named “Feed”) unpurified samples essentially taken from the fermentation media and Lane 3 are purified samples. [0055] As can be seen—the purified samples are within the scope of item (ii) of the first aspect—i.e. they are samples, wherein at least 70% of the total amounts of proteins with a size bigger than 10 kDa are the milk clotting aspartic protease enzyme. [0056] The not purified samples are not within the scope of item (ii) of the first aspect. [0057] SDS-PAGE is a well-known technology for the skilled person—i.e. it is routine work for the skilled person to determine if purified milk clotting aspartic protease enzyme sample of interest is a sample with the scope of item (ii) of the first aspect. [0058] In FIG. 1 herein can be seen that there are two bands in the migration range 34-38 kDa for e.g. CHY-MAX® in purified sample of lane 3. [0059] Without being limited to theory—it is believed that these two bands represent two different glycosylated forms of CHY-MAX®. [0060] As understood by the skilled person in the present context—both of these different glycosylated forms are milk clotting aspartic protease enzymes, since they both have milk-clotting enzymatic activity. [0061] As understood by the skilled person in the present context—the term “IMCU/g of the sample” in item (i) relates to IMCU enzyme activity per gram of the sample as such. [0062] Similar—the term “IMCU/g of the composition” in item (I) relates to IMCU enzyme activity per gram of the composition as such. [0063] It may be preferred that the liquid composition of the first aspect has a total weight of from 10 g to 10,000 kg. [0064] As known to the skilled person in the present context—a herein relevant liquid composition of the first aspect that has a weight of 1 kg will approximately have a volume of 1 liter. [0065] A second aspect of the invention relates to a liquid milk clotting aspartic protease enzyme composition obtainable by a method of the first aspect or any herein relevant embodiments thereof. [0066] The first and second aspects herein relate to a liquid composition—however, milk clotting aspartic protease enzymes (e.g. chymosin) may also be commercialized as dried granulated composition/product. [0067] Accordingly, a third aspect of the invention relates to a method for making a dried milk clotting aspartic protease enzyme composition, wherein the method comprises the steps of: (1): first making a liquid milk clotting aspartic protease enzyme composition according to the method of the first aspect or any herein relevant embodiments thereof; (2): drying and granulating the liquid composition of step (1) to get the dried granulated milk clotting aspartic protease enzyme composition. [0070] The drying step (2) may be seen as a routine step for the skilled person in the present context—it is therefore not necessary to describe this step as such in details herein. [0071] A fourth aspect of the invention relates to a dried granulated milk clotting aspartic protease enzyme composition obtainable by a method of the third aspect or any herein relevant embodiments thereof. [0072] A fifth aspect of the invention relates to a liquid milk clotting aspartic protease enzyme composition comprising: (I): milk clotting aspartic protease enzyme at a strength of from 25 IMCU/g to 30,000 IMCU/g of the composition; (II): not milk clotting aspartic protease enzyme polypeptides longer than 10 amino acids in a concentration from 0.01% to 10% (w/w) of the composition; and (III): a salt in a concentration from 1 to 350 g/kg and wherein the pH of the composition is from 2 to 8; and (x): wherein the polypeptides longer than 10 amino acids of item (II) are at least one polypeptide selected from the group of polypeptides consisting of: whey proteins, alpha lactalbumin, beta-lactoglobulin, transferrin, lactoperoxidase, casein, alpha-s1-casein, alpha-s2-casein, beta-casein, kappa-casein, ovalbumin, gelatin, bovine serum albumin, soy proteins, pea proteins, corn proteins, potato proteins, hemp proteins, rice proteins, spirulina proteins, wheat proteins, peanut proteins, sun flower proteins, rape seed proteins, blood proteins and algae proteins. [0077] In the present context—the skilled person will know or may routinely determine (e.g. based on specific relevant amino acid sequences) the origin of the polypeptides longer than 10 amino acids of item (x). [0078] As understood by the skilled person in the present context—the term “g/kg” in relation to item (III) relates to gram salt per kg of the composition as such. [0079] A sixth aspect of the invention relates to a dried granulated milk clotting aspartic protease enzyme composition comprising: (I): milk clotting aspartic protease enzyme at a strength of from 25 IMCU/g to 30,000 IMCU/g of the composition; (II): not milk clotting aspartic protease enzyme polypeptides longer than 10 amino acids in a concentration from 0.01% to 10% (w/w) of the composition; and (III): a salt and wherein the pH of the composition suspended in water is from 2 to 8; and (x): wherein the polypeptides longer than 10 amino acids of item (II) are at least one polypeptide selected from the group of polypeptides consisting of: whey proteins, alpha lactalbumin, beta-lactoglobulin, transferrin, lactoperoxidase, casein, alpha-s1-casein, alpha-s2-casein, beta-casein, kappa-casein, ovalbumin, gelatin, bovine serum albumin, soy proteins, pea proteins, corn proteins, potato proteins, hemp proteins, rice proteins, spirulina proteins, wheat proteins, peanut proteins, sun flower proteins, rape seed proteins, blood proteins and algae proteins. [0084] A seventh aspect of the invention relates to a liquid milk clotting aspartic protease enzyme composition comprising milk clotting aspartic protease enzyme at a strength of from 1600 IMCU/g to 30,000 IMCU/g of the composition and a salt in a concentration from 1 to 350 g/kg and wherein the pH of the composition is from 2 to 8. [0085] An eight aspect of the invention relates to a dried granulated milk clotting aspartic protease enzyme composition comprising milk clotting aspartic protease enzyme at a strength of from 1600 IMCU/g to 30,000 IMCU/g of the composition and a salt and wherein the pH of the composition suspended in water is from 2 to 8. [0086] A milk clotting aspartic protease enzyme composition as described herein may be used according to the art—e.g. to make a food or feed product of interest (such as e.g. a milk based product of interest that e.g. could be a cheese product). [0087] Accordingly, a ninth aspect of the invention relates to a method for making a food or feed product comprising adding an effective amount of a milk clotting aspartic protease enzyme composition of any of fifth to eight aspect or any herein relevant embodiments thereof to the food or feed ingredient(s) and carrying out further manufacturing steps to obtain the food or feed product. Definitions [0088] All definitions of herein relevant terms are in accordance of what would be understood by the skilled person in relation to the herein relevant technical context. [0089] The term “milk-clotting enzyme” refers to an enzyme with milk-clotting enzymatic activity—i.e. an active milk-clotting enzyme. The milk-clotting activity may be expressed in International Milk-Clotting Units (IMCU) per ml or IMCU per g. The skilled person knows how to determine herein relevant milk-clotting enzymatic activity. In working Example 1 herein is provided an example of a standard method to determine milk-clotting enzymatic activity and specific milk-clotting enzymatic activity. As known in the art—specific clotting activity (IMCU/mg total protein) is determined by dividing the clotting activity (IMCU/ml) by the total protein content (mg total protein per ml). [0090] The term “Sequence Identity” relates to the relatedness between two amino acid sequences. [0091] For purposes of the present invention, the degree of sequence identity between two amino acid sequences is determined according to the art and preferably determined using the Needleman-Wunsch algorithm (Needleman and Wunsch, 1970, J. Mol. Biol. 48: 443-453) as implemented in the Needle program of the EMBOSS package (EMBOSS: The European Molecular Biology Open Software Suite, Rice et al., 2000, Trends Genet. 16: 276-277), preferably version 3.0.0 or later. The optional parameters used are gap open penalty of 10, gap extension penalty of 0.5, and the EBLOSUM62 (EMBOSS version of BLOSUM62) substitution matrix. The output of Needle labeled “longest identity” (obtained using the -nobrief option) is used as the percent identity and is calculated as follows: [0000] (Identical Residues×100)/(Length of Alignment−Total Number of Gaps in Alignment). [0092] The term “variant” means a peptide having milk-clotting enzymatic activity comprising an alteration, i.e., a substitution, insertion, and/or deletion, at one or more (several) positions. A substitution means a replacement of an amino acid occupying a position with a different amino acid; a deletion means removal of an amino acid occupying a position; and an insertion means adding 1-3 amino acids adjacent to an amino acid occupying a position. [0093] The amino acid may be natural or unnatural amino acids—for instance, substitution with e.g. a particularly D-isomers (or D-forms) of e.g. D-alanine could theoretically be possible. [0094] Embodiment of the present invention is described below, by way of examples only. DRAWINGS [0095] FIG. 1 : In FIG. 1 herein is shown SDS-PAGE data for different samples of bovine chymosin (CHY-MAX®, Chr. Hansen A/S) and mucorpepsin (Hannilase®, Chr. Hansen A/S). For both CHY-MAX® and Hannilase® are Lane 2 (named “Feed”) unpurified samples essentially taken from the fermentation media and Lane 3 are purified samples. [0096] FIG. 2 : Shows some of the results of inversion experiments as discussed herein to determine herein relevant physical stability. See working Example herein for further details. [0097] FIG. 3 : Conformational stability of an enzyme is illustrated. [0098] FIG. 4 : An alignment of herein relevant different milk clotting chymosin sequences from different mammalian species (cow, buffalo, goat, sheep, camel and pig). All the sequences of FIG. 4 are public available. [0099] FIG. 5 : An alignment of herein relevant commercially available different milk clotting aspartic protease enzymes sequences from different mammalian or fungal species (camel chymosin, cow chymosin, cow pepsin, fungal mucor pepsin and fungal Endothia pepsin). All the sequences of FIG. 5 are public available. DETAILED DESCRIPTION OF THE INVENTION Milk Clotting Aspartic Protease Enzyme [0100] The discussion of specific embodiments/examples of herein relevant milk clotting aspartic protease enzymes below is relevant for all the aspects of the invention as discussed herein. [0101] In a preferred embodiment, the milk clotting aspartic protease enzyme is a milk-clotting enzyme selected from the group consisting of chymosin (EC 3.4.23.4), pepsin (EC 3.4.23.1) and mucorpepsin (EC 3.4.23.23). [0102] As discussed in working Examples herein—the herein relevant increase in the specific activity and strength were most significant for the bovine and camel chymosin compositions. [0103] Accordingly, in a preferred embodiment the milk clotting aspartic protease enzyme is chymosin (EC 3.4.23.4). [0104] A preferred milk clotting aspartic protease enzyme is Camelius dromedarius chymosin as described in e.g. WO02/36752A2 (Chr. Hansen). It may herein alternatively be termed camel chymosin and the publically known mature polypeptide amino acid sequence is shown in FIG. 5 herein. [0105] As known in the art—it is routine work for the skilled person to make variants (i.e. amino acid modifications) of an enzyme of interest without significantly changing the characteristics of the enzyme. [0106] Accordingly, in a preferred embodiment the milk clotting aspartic protease enzyme is Camelius dromedarius chymosin comprising the polypeptide amino acid sequence shown in FIG. 5 herein (termed “Camel_chymosin”) or a variant of Camelius dromedarius chymosin, wherein the variant comprises a polypeptide sequence which has at least 90% (preferably at least 95%, more preferably at least 99%) sequence identity with the camel chymosin polypeptide amino acid sequence shown in FIG. 5 herein. [0107] A preferred milk clotting aspartic protease enzyme is bovine chymosin. It may herein alternatively be termed cow chymosin and the publically known mature polypeptide amino acid sequence is shown in FIG. 5 herein. [0108] Accordingly, in a preferred embodiment the milk clotting aspartic protease enzyme is bovine chymosin comprising the polypeptide amino acid sequence shown in FIG. 5 herein (termed “Cow_chymosin”) or a variant of bovine chymosin, wherein the variant comprises a polypeptide sequence which has at least 90% (preferably at least 95%, more preferably at least 99%) sequence identity with the bovine chymosin polypeptide amino acid sequence shown in FIG. 5 herein. [0109] A preferred milk clotting aspartic protease enzyme is bovine pepsin. It may herein alternatively be termed cow pepsin and the publically known mature polypeptide amino acid sequence is shown in FIG. 5 herein. [0110] Accordingly, in a preferred embodiment the milk clotting aspartic protease enzyme is bovine pepsin comprising the polypeptide amino acid sequence shown in FIG. 5 herein (termed “Cow_pepsin”) or a variant of bovine pepsin, wherein the variant comprises a polypeptide sequence which has at least 90% (preferably at least 95%, more preferably at least 99%) sequence identity with the bovine pepsin polypeptide amino acid sequence shown in FIG. 5 herein. [0111] A preferred milk clotting aspartic protease enzyme is Mucor pepsin (see e.g. EP0805866B1 (Harboe et al, Chr. Hansen A/S, Denmark)). The publically known mature polypeptide amino acid sequence is shown in FIG. 5 herein. [0112] Accordingly, in a preferred embodiment the milk clotting aspartic protease enzyme is Mucor pepsin comprising the polypeptide amino acid sequence shown in FIG. 5 herein (termed “Mucor”) or a variant of Mucor pepsin, wherein the variant comprises a polypeptide sequence which has at least 90% (preferably at least 95%, more preferably at least 99%) sequence identity with the Mucor pepsin polypeptide amino acid sequence shown in FIG. 5 herein. [0113] A preferred milk clotting aspartic protease enzyme is Endothia pepsin. The publically known mature polypeptide amino acid sequence is shown in FIG. 5 herein. [0114] Accordingly, in a preferred embodiment the milk clotting aspartic protease enzyme is Endothia pepsin comprising the polypeptide amino acid sequence shown in FIG. 5 herein (termed “Endothia”) or a variant of Endothia pepsin, wherein the variant comprises a polypeptide sequence which has at least 90% (preferably at least 95%, more preferably at least 99%) sequence identity with the Endothia pepsin polypeptide amino acid sequence shown in FIG. 5 herein. Added Polypeptide/Proteins [0115] As discussed above—step (b) of the method of the first aspect reads: step (b): adding a suitable amount of a polypeptide formulation comprising polypeptides longer than 10 amino acids to the sample of step (a), wherein the polypeptides are not milk clotting aspartic protease enzymes and not enzymes that degrade the aspartic protease enzymes, to get a liquid milk clotting aspartic protease enzyme composition, [0117] As discussed above—item (II) of the liquid milk clotting aspartic protease enzyme composition of the fifth aspect and item (II) of the dried granulated milk clotting aspartic protease enzyme composition of the sixth aspect reads: (II): not milk clotting aspartic protease enzyme polypeptides longer than 10 amino acids in a concentration from 0.01% to 10% (w/w) of the composition; [0119] The discussion of specific embodiments/examples of herein relevant “polypeptides longer than 10 amino acids” below is relevant for all the aspects of the invention as discussed herein. [0120] In the present context, it is evident that in step (b) of the method of the first aspect it is not preferred to add enzymes that degrade the aspartic protease enzymes and the term “not enzymes that degrade the aspartic protease enzymes” of step (b) should be understood in relation to this. [0121] Preferably, the polypeptides longer than 10 amino acids are at least one polypeptide selected from the group of polypeptides consisting of: whey proteins, alpha lactalbumin, beta-lactoglobulin, transferrin, lactoperoxidase, casein, alpha-s1-casein, alpha-s2-casein, beta-casein, kappa-casein, ovalbumin, gelatin, bovine serum albumin, soy proteins, pea proteins, corn proteins, potato proteins, hemp proteins, rice proteins, spirulina proteins, wheat proteins, peanut proteins, sun flower proteins, rape seed proteins, blood proteins and algae proteins. [0122] More preferably, the polypeptides longer than 10 amino acids are at least one polypeptide selected from the group of polypeptides consisting of: whey proteins, alpha lactalbumin, beta-lactoglobulin, transferrin, lactoperoxidase, casein, alpha-s1-casein, alpha-s2-casein, beta-casein, kappa-casein, ovalbumin, gelatin and bovine serum albumin. [0123] Within the group immediately above it is preferred that the polypeptides longer than 10 amino acids are at least one polypeptide selected from the group of polypeptides consisting of: whey proteins, alpha lactalbumin, beta-lactoglobulin, casein, alpha-s1-casein, alpha-s2-casein, beta-casein, kappa-casein, ovalbumin, gelatin and bovine serum albumin. [0124] In a preferred embodiment—polypeptides longer than 10 amino acids are polypeptides longer than 25 amino acids, more preferably polypeptides longer than 40 amino acids. [0125] As discussed in working Examples herein—herein relevant positive results were obtained by addition of e.g. whey protein, ovalbumin and BSA, which herein all may be characterized as relatively large proteins. [0126] As known in the art—the term peptide may be distinguished from the term protein on the basis of size, which as and as an arbitrary benchmark may be understood to be approximately 50 or fewer amino acids. [0127] Said in other words, a polypeptide longer than 50 amino acids may normally in the art be understood to be a protein. [0128] Accordingly, a polypeptide longer than 50 amino acids may herein alternatively be termed a protein. [0129] In a preferred embodiment—polypeptides longer than 10 amino acids are proteins longer than 50 amino acids, more preferably proteins longer than 75 amino acids, even more preferably proteins longer than 150 amino acids. [0130] It may even be preferred that polypeptides longer than 10 amino acids are proteins longer than 300 amino acids. First Aspect—A Method for Making a Liquid Milk Clotting Aspartic Protease Enzyme Composition [0131] As discussed above—the first aspect of the invention relates to a method for making a liquid milk clotting aspartic protease enzyme composition, wherein the method comprises the steps of: (a): obtaining a purified liquid milk clotting aspartic protease enzyme sample comprising: (i): a strength of from 25 IMCU/g to 30,000 IMCU/g of the sample; and (ii): wherein at least 70% of the total amounts of proteins with a size bigger than 10 kDa, determined by SDS-PAGE, in the purified sample are milk clotting aspartic protease enzyme; and (b): adding a suitable amount of a polypeptide formulation comprising polypeptides longer than 10 amino acids to the sample of step (a), wherein the polypeptides are not milk clotting aspartic protease enzymes and not enzymes that degrade the aspartic protease enzymes, to get a liquid milk clotting aspartic protease enzyme composition, wherein the composition comprises: (I): milk clotting aspartic protease enzyme at a strength of from 26 IMCU/g to 30,100 IMCU/g of the composition; and (II): the in step (b) added not milk clotting aspartic protease enzyme polypeptides longer than 10 amino acids in a concentration from 0.01% to 10% (w/w) of the composition; and wherein the strength (IMCU/g of the composition) in (I) is at least 1% higher than the strength in (i) (IMCU/g of the sample), measured after one week of storage at 5° C. [0138] In a preferred embodiment, the strength (IMCU/g of the composition) in (I) is at least 3% higher than the strength in (i) (IMCU/g of the composition), measured after one week of storage at 5° C.; more preferably the strength (IMCU/g of the composition) in (I) is at least 7% higher than the strength in (i) (IMCU/g of the composition), measured after one week of storage at 5° C.; even more preferably the strength (IMCU/g of the composition) in (I) is at least 10% higher than the strength in (i) (IMCU/g of the composition), measured after one week of storage at 5° C.; and most preferably the strength (IMCU/g of the composition) in (I) is at least 15% higher than the strength in (i) (IMCU/g of the composition), measured after one week of storage at 5° C. [0139] Preferred examples/embodiments of milk clotting aspartic protease enzymes are described above. [0140] Preferred examples/embodiments of “polypeptides longer than 10 amino acids” are described above. [0141] It is preferred that the enzyme strength in item (i) is a strength of from 100 IMCU/g of the sample to 10,000 IMCU/g of the sample, more preferably a strength of from 500 IMCU/g of the sample to 6000 IMCU/g of the sample. [0142] It is preferred that the enzyme strength in item (I) is a strength of from 100 IMCU/g of the composition to 10,000 IMCU/g of the composition, more preferably a strength of from 500 IMCU/g of the composition to 6000 IMCU/g of the composition. [0143] Preferably, the purified sample of step (a)(ii) is a sample, wherein at least 80% of the total amounts of proteins with a size bigger than 10 kDa, determined by SDS-PAGE, in the purified sample are milk clotting aspartic protease enzyme; [0144] more preferably, wherein at least 90% of the total amounts of proteins with a size bigger than 10 kDa, determined by SDS-PAGE, in the purified sample are milk clotting aspartic protease enzyme; [0145] even more preferably wherein at least 95% of the total amounts of proteins with a size bigger than 10 kDa, determined by SDS-PAGE, in the purified sample are milk clotting aspartic protease enzyme. [0146] It may be preferred that at least 99% of the total amounts of proteins with a size bigger than 10 kDa, determined by SDS-PAGE, in the purified sample are milk clotting aspartic protease enzyme. [0147] As known to the skilled person—in the present context it is routine work for the skilled person to obtain purified liquid milk clotting aspartic protease enzyme sample as discussed herein—for instance by use of suitable chromatography (e.g. column chromatography) isolation procedures. As such chromatography is well known to the skilled person are it is therefore not necessary to describe chromatography procedures as such in details herein. [0148] For instance, WO02/36752A2 (Chr. Hansen) describes a recombinant method to produce Camelius dromedarius chymosin (Camel chymosin) using Aspergillus cells (preferably Aspergillus niger ) as production host cells. [0149] It is also known to use other cells as production host cells—such as e.g. yeast cell, where an example is e.g. Kluyveromyces cells (for instance Kluyveromyces lactis ). [0150] Accordingly, it may be preferred that the purified sample of step (a)(ii) is a sample obtained from recombinant production of the milk clotting aspartic protease enzyme in fungal or yeast production host cells, such as e.g. Aspergillus cells or Kluyveromyces cells. [0151] As known in the art—Mucorpepsin derived from Rhizomucor miehei may preferably be produced by use of Rhizomucor miehei as production host cell. [0152] In relation to item (II)—it is preferred that the in step (b) added not milk clotting aspartic protease enzyme polypeptides longer than 10 amino acids is in a concentration from 0.05% to 8% (w/w) of the composition; more preferably in a concentration from 0.1% to 7% (w/w) of the composition; even more preferably in a concentration from 0.25% to 5% (w/w) of the composition and most preferably in a concentration from 0.5% to 4% (w/w) of the composition (such as e.g. in a concentration from 1% to 3% (w/w) of the composition). [0000] Fifth and/or Sixth Aspect—A Liquid and/or Dried Milk Clotting Aspartic Protease Enzyme Composition [0153] As discussed above—the fifth aspect of the invention relates to a liquid milk clotting aspartic protease enzyme composition comprising: (I): milk clotting aspartic protease enzyme at a strength of from 25 IMCU/g to 30,000 IMCU/g of the composition; (II): not milk clotting aspartic protease enzyme polypeptides longer than 10 amino acids in a concentration from 0.01% to 10% (w/w) of the composition; and (III): a salt in a concentration from 1 to 350 g/kg and wherein the pH of the composition is from 2 to 8; and (x): wherein the polypeptides longer than 10 amino acids of item (II) are at least one polypeptide selected from the group of polypeptides consisting of: whey proteins, alpha lactalbumin, beta-lactoglobulin, transferrin, lactoperoxidase, casein, alpha-s1-casein, alpha-s2-casein, beta-casein, kappa-casein, ovalbumin, gelatin, bovine serum albumin, soy proteins, pea proteins, corn proteins, potato proteins, hemp proteins, rice proteins, spirulina proteins, wheat proteins, peanut proteins, sun flower proteins, rape seed proteins, blood proteins and algae proteins. [0158] As discussed above—the sixth aspect of the invention relates to a dried granulated milk clotting aspartic protease enzyme composition comprising: (I): milk clotting aspartic protease enzyme at a strength of from 25 IMCU/g to 30,000 IMCU/g of the composition; (II): not milk clotting aspartic protease enzyme polypeptides longer than 10 amino acids in a concentration from 0.01% to 10% (w/w) of the composition; and (III): a salt and wherein the pH of the composition suspended in water is from 2 to 8; and (x): wherein the polypeptides longer than 10 amino acids of item (II) are at least one polypeptide selected from the group of polypeptides consisting of: whey proteins, alpha lactalbumin, beta-lactoglobulin, transferrin, lactoperoxidase, casein, alpha-s1-casein, alpha-s2-casein, beta-casein, kappa-casein, ovalbumin, gelatin, bovine serum albumin, soy proteins, pea proteins, corn proteins, potato proteins, hemp proteins, rice proteins, spirulina proteins, wheat proteins, peanut proteins, sun flower proteins, rape seed proteins, blood proteins and algae proteins. [0163] For both the liquid and the dried composition—preferred examples/embodiments of milk clotting aspartic protease enzymes are described above. [0164] For both the liquid and the dried composition—preferred examples/embodiments of “polypeptides longer than 10 amino acids” are described above. [0165] For both the liquid and the dried composition—it is preferred that the enzyme strength in item (I) is a strength of from 100 IMCU/g of the composition to 10,000 IMCU/g of the composition, more preferably a strength of from 500 IMCU/g of the composition to 6000 IMCU/g of the composition. [0166] For both the liquid and the dried composition—in relation to item (II), it is preferred the not milk clotting aspartic protease enzyme polypeptides longer than 10 amino acids is in a concentration from 0.05% to 8% (w/w) of the composition; more preferably in a concentration from 0.1% to 7% (w/w) of the composition; even more preferably in a concentration from 0.25% to 5% (w/w) of the composition and most preferably in a concentration from 0.5% to 4% (w/w) of the composition (such as e.g. in a concentration from 1% to 3% (w/w) of the composition). [0167] For the liquid composition—the salt in item (iii) is preferably in a concentration from 10 to 300 g/kg, more preferably is in a concentration from 25 to 250 g/kg. [0168] As known to the skilled person—for the dried composition the salt concentration in item (iii) may be relatively high—such as e.g. from 50% (w/w) to 99.9% (w/w) or such as e.g. from 80% (w/w) to 99% (w/w). [0169] For both the liquid and the dried composition—it is preferred that the salt is an inorganic salt—preferably wherein the inorganic salt is selected from the group of NaCl, KCl, Na 2 SO 4 , (NH 4 ) 2 SO 4 , K 2 HPO 4 , KH 2 PO 4 , Na 2 HPO 4 or NaH 2 PO 4 or a combination thereof. Most preferably, the salt is NaCl. [0170] Both the liquid and the dried composition may comprise further additives/compounds such as e.g. a preservative. [0171] As known to the skilled person—preservative may generally be added in a concentration sufficient to prevent microbial growth during shelf life of the product. [0172] Examples of preservatives may be e.g. weak organic acids such as formate, acetate, lactate, propionate, malate, benzoate, sorbate or fumarate. Parabens (alkyl esters of para-hydroxybenzoate) may also be used as preservative. Glycerol or propanediol has also been described as preservatives. [0173] Both the liquid and the dried composition—it is preferred that the pH is from 3 to 7, more preferably that the pH is from 4 to 6.5 and even more preferably that the pH is from 5 to 6. [0174] Preferably, the liquid composition is an aqueous composition, for instance an aqueous solution. As used herein an aqueous composition or aqueous solution encompasses any composition or solution comprising water, for instance at least 20 wt % of water, for instance at least 40 wt % of water. [0175] It may be preferred that the liquid composition as described herein has a total weight of from 10 g to 10,000 kg, such as e.g. from 100 g to 3000 kg. [0176] It may be preferred that the dried granulated composition as described herein has a total weight of from 0.25 g to 200 kg, such as e.g. from 0.5 g to 50 kg. [0177] It is preferred that the composition is a liquid milk clotting aspartic protease enzyme composition as described herein. [0178] For both the liquid and the dried composition—a preferred embodiment is: (y): wherein the sum of the amounts of aspartic protease enzyme of item (I) and polypeptides longer than 10 amino acids of item (II), determined by SDS-PAGE, are higher than 50% (w/w) of the total amount of proteins and/or polypeptides longer than 10 amino acids in the composition; more preferably (y): wherein the sum of the amounts of aspartic protease enzyme of item (I) and polypeptides longer than 10 amino acids of item (II), determined by SDS-PAGE, are higher than 70% (w/w) of the total amount of proteins and/or polypeptides longer than 10 amino acids in the composition; even more preferably (y): wherein the sum of the amounts of aspartic protease enzyme of item (I) and polypeptides longer than 10 amino acids of item (II), determined by SDS-PAGE, are higher than 80% (w/w) of the total amount of proteins and/or polypeptides longer than 10 amino acids in the composition; and most preferably (y): wherein the sum of the amounts of aspartic protease enzyme of item (I) and polypeptides longer than 10 amino acids of item (II), determined by SDS-PAGE, are higher than 90% (w/w) of the total amount of proteins and/or polypeptides longer than 10 amino acids in the composition. [0183] In the present context—the skilled person will know or may routinely determine (e.g. based on specific relevant amino acid sequences) the origin of the polypeptides longer than 10 amino acids of item (x). [0184] Accordingly, the skilled person may therefore also routine determine (e.g. via SDS-PAGE) if item (y) is fulfilled in a herein relevant composition of interest. Seventh Aspect and Eight Aspect [0185] As discussed above—the seventh aspect of the invention relates to a liquid milk clotting aspartic protease enzyme composition comprising milk clotting aspartic protease enzyme at a strength of from 1600 IMCU/g to 30,000 IMCU/g of the composition and a salt in a concentration from 1 to 350 g/kg and wherein the pH of the composition is from 2 to 8. [0186] An eight aspect of the invention relates to a dried granulated milk clotting aspartic protease enzyme composition comprising milk clotting aspartic protease enzyme at a strength of from 1600 IMCU/g to 30,000 IMCU/g of the composition and a salt and wherein the pH of the composition suspended in water is from 2 to 8. [0187] For both the liquid and the dried composition—preferably, the strength is a strength of from 2000 IMCU/g to 15,000 IMCU/g of the composition, such as from 3000 IMCU/g to 10,000 IMCU/g of the composition or such as from 4000 IMCU/g to 8000 IMCU/g of the composition. Ninth Aspect—A Method for a Method for Making a Food or Feed Product [0188] As discussed above—a milk clotting aspartic protease enzyme composition as described herein may be used according to the art—e.g. to make a milk based product of interest (such as e.g. a cheese product). [0189] As discussed above—the ninth aspect of the invention relates to a method for making a food or feed product comprising adding an effective amount of a milk clotting aspartic protease enzyme composition of any of fifth to eight aspect or any herein relevant embodiments thereof to the food or feed ingredient(s) and carrying out further manufacturing steps to obtain the food or feed product. [0190] Preferably, the food or feed product is a milk based product and wherein the method comprises adding an effective amount of the isolated chymosin polypeptide variant as described herein to milk and carrying our further manufacturing steps to obtain the milk based product. [0191] The milk may e.g. be sheep milk, goat milk, buffalo milk, yak milk, lama milk, camel milk or cow milk. [0192] The milk based product may e.g. be a fermented milk product, a quark or a cheese. [0193] It may be preferred that the method for making a food or feed product of the fourth aspect or herein relevant embodiments thereof is a method, wherein a milk clotting aspartic protease enzyme composition first have been stored according to the method for storage of a milk clotting aspartic protease enzyme of the third aspect and thereafter added to the food or feed ingredient(s) according to the method for making a food or feed product of the fourth aspect. EXAMPLES Example 1 Determination of Specific Milk-Clotting Activity 4.1 Determination of Clotting Activity [0194] Milk clotting activity was determined using the REMCAT method, which is the standard method developed by the International Dairy Federation (IDF method). [0195] Milk clotting activity is determined from the time needed for a visible flocculation of a standard milk substrate prepared from a low-heat, low fat milk powder with a calcium chloride solution of 0.5 g per litre (pH≈6.5). The clotting time of a milk-clotting enzyme sample is compared to that of a reference standard having known milk-clotting activity and having the same enzyme composition by IDF Standard 110B as the sample. Samples and reference standards were measured under identical chemical and physical conditions. Variant samples were adjusted to approximately 3 IMCU/ml using an 84 mM acetic acid pH 5.5 buffer. Hereafter, 200 μl enzyme was added to 10 ml preheated milk (32° C.) in a glass test tube placed in a water bath, capable of maintaining a constant temperature of 32° C.±1° C. under constant stirring. [0196] The total milk-clotting activity (strength) of a milk-clotting enzyme is calculated in International Milk-Clotting Units (IMCU) per ml relative to a standard having the same enzyme composition as the sample according to the formula: [0000] Strength   in   IMCU  /  ml = Sstandard × Tstandard × Dsample Dstandard × Tsample Sstandard: The milk-clotting activity of the international reference standard for rennet. Tstandard: Clotting time in seconds obtained for the standard dilution. Dsample: Dilution factor for the sample Dstandard: Dilution factor for the standard Tsample: Clotting time in seconds obtained for the diluted rennet sample from addition of enzyme to time of flocculation 4.2 Determination of Total Protein Content [0202] Total protein content was determined using the Pierce BCA Protein Assay Kit from Thermo Scientific following the instructions of the providers. 4.3 Calculation of Specific Clotting Activity [0203] Specific clotting activity (IMCU/mg total protein) was determined by dividing the clotting activity (IMCU/ml) by the total protein content (mg total protein per ml). Example 2 Enzyme Preparations [0204] Bovine chymosin (CHY-MAX®, Chr. Hansen A/S) or camel chymosin (CHY-MAX® M, Chr. Hansen A/S) were recombinantly expressed in Aspergillus niger (roughly as described in WO02/36752A2). The enzymes were purified by chromatography technology. Mucorpepsin (Hannilase®, Chr. Hansen A/S) derived from Rhizomucor miehei was produced by use of Rhizomucor miehei as production host cell and purified by chromatography technology. For all the purified enzyme samples—at least 90% of the total amounts of proteins with a size bigger than 10 kDa, determined by SDS-PAGE, in the purified sample were the relevant milk clotting aspartic protease enzymes. [0205] All enzyme samples were prepared by mixing an exact volume for a stock solution of the enzyme with a solution of the additive and adding buffer to a final volume. In this manner the concentration of enzyme protein is kept constant for all prepared samples. Buffer composition was: 0.25 M sodium acetate, 20 mM sodium phosphate, 2.0 M sodium chloride, pH 5.7, 5 mM methionine, and 35 mM sodium benzoate. The strength was from 200 to 1200 IMCU/ml. The composition was added different polypeptides such as Hammersten casein, WPC80, Lacprodan Alpha 10, Lacprodan Alpha 20, etc. [0206] WPC80 is a commercial preparation of dried whey protein concentrate with 80% protein. Lacprodan Alpha 10 and Lacprodan Alpha 20 are commercial preparations of whey protein isolate containing 43% and 60% alpha lactalbumin of total protein content, respectively. Example 3 Physical Stability of Camel Chymosin [0207] Liquid formulations of industrial enzymes are subjected to physical forces from unit operations such as pumping, stirring and filtration over membranes. During transportation of partly filled containers sloshing around of liquid formulation may also contribute to this. Shear stress and increased exposure of enzyme to the water-air interface may induce denaturation and concomitant loss of enzyme activity. [0208] Physical stability of an enzyme or protein sample can be tested by repeatable shaking a sample of the enzyme in a test tube having high head space to sample volume ratio. The stability of different aspartic proteases towards shaking was investigated by inverting a 2 ml sample filled in a 10 ml tube in a rotary device for 1 hour (see FIG. 2 herein). For each solution, relative milk clotting activity was measured after 1 hour of vertical inversion (at room temperature) and compared to a non-inverted control having the exact same composition. Results were expressed as “retained activity” which is obtained by diving activity of the inverted sample with the activity of the non-inverted control sample. Results: [0209] Vertical inversion for 1 hr of a sample of camel chymosin results in an activity loss of more than 30% cf. Table 1 (No addition). Addition of PEG8000 to a concentration of 0.015% was found to protect camel chymosin and resulting in no loss of activity upon vertical inversion. When the sample of camel chymosin contained Hammersten casein, Alpha 10, Alpha 20 or WPC 80 at a concentration of either 0.5% w/v or 1.0% w/v practically no loss upon vertical inversion was seen. [0210] The protecting effect of Alpha 20 and WPC 80 was found to decrease gradually when their concentration was decreased below 0.1%. A formulation of camel chymosin with either acid casein hydrolysate or whey permeate did not increase stability of the enzyme as the loss in activity upon vertical inversion was the same as for the untreated control sample (Table 3). [0211] Conclusion: The results show that certain proteins added to a preparation of camel chymosin can increase the physical stability of the enzyme. [0000] TABLE 1 Retained activity of camel chymosin samples subjected to vertical inversion for 1 hr (Internal ref number: EXP-13-AD2681). Compound Retained activity No addition 67% (3%) PEG (0.015%) 99% (0%) Glycerol (6%) 67% (4%) 0.5% Hammersten casein 97% (0%) 1% Hammersten casein 97% (1%) 0.5% Casein hydrolysate (Merck) 67% (4%) 1% Casein hydrolysate (Merck) 74% (5%) 0.5% Alpha 10 (Prøve 1) 98% (0%) 1% Alpha 10 (Prøve 1) 98% (0%) 0.5% Alpha 20 (Prøve 2) 98% (0%) 1% Alpha 20 98% (0%) 0.5% Permeat  64% (17%) 1% Permeat 69% (1%) 0.1% WPC 80 100% (0%)  1% WPC 80 99% (0%) Example 4 Specific Activity of Camel Chymosin Results: [0212] The inversion experiments were designed so the exact same amount of enzyme protein was added in each experiment and all formulations were made up to the same volume. If composition of the formulation did not influence enzymatic activity, one would expect to find the same enzymatic activity of all control samples, i.e. samples not inverted. However, this was not the case. Samples containing PEG8000 were 4-5% higher in activity in good accordance with recently submitted patent application IN5103DK00. Samples containing Hammerstein casein, Alpha 20 or WPC 80 had 13-18% higher activity compared to the sample without additives (no addition) even though the same amount of enzyme protein was applied (Table 2). This shows that the presence milk proteins in the formulation of camel chymosin increase the specific activity of the enzyme. The same conclusion is made from Table 3 which shows the activity of compositions containing Alpha 20 and WPC80 at five different concentrations. Table 5 show activity of the composition, activity index with ‘no addition’=100%, and the retained activity of a sample subjected to vertical inversion for 1 hr. [0213] Addition of polypeptides to a composition of camel chymosin has two effects on the enzyme: Increase in specific activity and an increased physical stability of the enzyme. Both properties correlate well with the dosage of polypeptide as seen from Table 3. In Table 3 it is found that when the concentration of Alpha 20 is decreased from 0.5 to 0.01%, the enzyme activity drops from index 115 to index 102 which is almost the same level as the untreated control. At a concentration of 0.01% Alpha 20 the physical stability (retained activity) of the enzyme is the same as in the control experiment (no addition). [0000] TABLE 2 Activity of CHY-MAX ® M added different polypeptides. Activity index relative to untreated control (‘no addition’) is shown in percentage (Internal ref number: EXP-13-AD2681). Compound Activity (IMCU/ml) No addition 1124 (13.3) 100% PEG (0.015%) 1163 (6.8)  104% Glycerol (6%) 1069 (12.0)  95% 0.5% Hammersten casein 1251 (12.3) 111% 1% Hammersten casein 1275 (25.0) 113% 0.5% Casein hydrolysate (Merck) 1112 (12.3)  99% 1% Casein hydrolysate (Merck) 1102 (19.8)  98% 0.5% Alpha 10 (Prøve 1) 1282 (8.6)  114% 1% Alpha 10 (Prøve 1) 1305 (9.9)  116% 0.5% Alpha 20 (Prøve 2) 1287 (5.0)  115% 1% Alpha 20 (Prøve 2) 1323 (1.2)  118% 0.5% Permeat (Prøve 3) 1147 (15.6) 102% 1% Permeat (Prøve 3) 1127 (32.2) 100% 0.1% WPC 80 (Prøve 4) 1248 (15.3) 111% 1% WPC 80 (Prøve 4) 1287 (2.8)  115% [0000] TABLE 3 Activity of CHY-MAX ® M added different polypeptides. Activity index relative to untreated control (‘no addition’) is shown in percentage. Column to the right show retained activity of camel chymosin samples subjected to vertical inversion for 1 hr (Internal ref number: EXP-13-AD2681). Compound Activity (IMCU/ml) Retained activity No addition 1102 (19.6) 100%  76% (4%) PEG, 0.015% 1153 (12.4) 105% 101% (2%) Alpha 20, 0.5% 1269 (13.0) 115% 100% (1%) Alpha 20, 0.25% 1224 (8.5)  111% 100% (1%) Alpha 20, 0.1 1162 (1.2)  105% 100% (0%) Alpha 20, 0.05% 1134 (7.2)  103%  97% (0%) Alpha 20, 0.01% 1129 (1.0)  102%  79% (0%) WPC 80, 0.5% 1235 (13.9) 112% 101% (1%) WPC 80, 0.25% 1227 (10.2) 111%  98% (0%) WPC 80, 0.1% 1155 (14.3) 105% 100% (1%) WPC 80, 0.05% 1141 (7.3)  104%  95% (2%) WPC 80, 0.01% 1112 (5.4)  101%  80% (1%) [0214] Conclusion: Addition of polypeptides to a composition of camel chymosin has two effects on the enzyme: Increase in specific activity and an increased physical stability of the enzyme. Both properties correlate well with the dosage of polypeptide. Example 5 Specific Activity of Camel Chymosin, Bovine Chymosin, Mucor Pepsin L and Mucor Pepsin XL [0215] [0000] TABLE 4 Activity of milk clotting enzymes added different polypeptides (Internal ref number: EXP-13-AD2690). Standard deviation in absolute numbers is in parenthesis. Compound CHY-MAX ® M CHY-MAX ® Hannilase L Hannilase XP Control 1066 (18.7) 100% 1117 (11.7) 100% 985 (4.0) 100% 1041 (2.3) 100% Alpha 20, 1108 (6.2) 104% 1143 (2.7) 102% 983 (9.4) 99% 1035 (7.1) 100% 0.1% Alpha 20, 1192 (20.1) 111% 1173 (3.3) 105% 994 (7.6) 100% 1044 (2.3) 100% 0.5% Alpha 20, 1225 (6.8) 116% 1191 (3.0) 107% 1,007 (11.0)  101% 1057 (5.1) 102% 1.0% WPC80 0.1% 1086 (11.4) 103% 1131 (9.1) 101%  980 (10.2) 101%  1030 (13.5) 100% WPC80 0.5% 1156 (11.0) 110% 1151 (7.2) 102% 995 (9.8) 101% 1034 (2.5) 99% WPC80 1.0% 1196 (20.5) 114% 1170 (15.6) 104% 997 (3.7) 102% 1047 (9.7) 101% [0216] Conclusion: The results in table 2-4 show that addition of polypeptides to a formulation of aspartic proteases increase the specific activity. Example 6 [0217] The table below show results from tests performed similar to Example 3 above—but using different protein formulations. All proteins shown in the table were added to a final content of 1% w/w and with gliadin as only exception gave clear solutions. Physical stability was tested according to example 3. Samples were stored for 1 year at 5° C. and 37° C., respectively, and stability was tested during storage period. The column ‘End of storage’ shows remaining activity after 1 year—the number was calculated by fitting a single exponential function to all data points. [0218] As known in the art—the term “peptone” refers to proteins digested by proteolysis. [0219] As known in the art—the term “tryptone” refers to proteins digested by the protease trypsin. [0000] TABLE 5 Activity of CHY-MAX M added different polypeptides at 1% w/w. Activity index relative to untreated control (‘no addition’) is shown in percentage. Column ‘Retained Activity’ show retained activity of camel chymosin samples subjected to vertical inversion for 1 hr. Column ‘End of Storage’ show activity after storage at 5° C. and 37° C. Standard deviation is shown in parenthesis. (Internal ref number: EXP-14-AE8307) Activity Retained End of storage Compound IMCU/ml/Index activity (5° C./37° C.) 1 Control (no addition) 389 (3.8) 100% 36% (2.4) 101%/14%  2 18332 Peptone (vegetable)  400 (11.1) 106% 95% (3.8) 91%/13% 3 51841 Peptone (vegetable) acid 418 (1.5) 109% 99% (4.6) 94%/13% hydrolysate 4 19942 Peptone (vegetable), no 1 422 (5.5) 108% 97% (0.6) 93%/15% 5 61854 Peptone (vegetable), no 2 423 (3.7) 109% 99% (1.4) 93%/13% 6 92976 Peptone special (vegetable) 423 (1.8) 110% 93% (7.1) 93%/13% 7 29185 Proteose Peptone (vegetable) 428 (3.0) 110% 97% (0.6) 94%/12% 8 16922 Tryptone (vegetable) 431 (2.9) 111% 96% (0.6) 93%/13% 9 12331 Tryptose (vegetable) 428 (2.0) 111% 94% (5)   96%/15% 10 05138 Vegetable Extract 412 (9.8) 109% 98% (2.3) 100%/14%  11 04316 Vegetable Extract no 1 414 (3.1) 108% 97% (5.1) 97%/15% 12 49869 Vegetable Extract no 2 409 (2.3) 106% 99% (3.5) 97%/15% 13 07436 Vegetable hydrolysate no 2 411 (5.8) 107% 101% (2.5)  98%/14% 14 67381 Vegetable Infusion powder 403 (5.9) 103% 99% (2.9) 102%/13%  15 95757 Vegetable Special Infusion 411 (1.6) 106% 98% (6.4) 99%/18% powder 16 83059 Peptone from potatoes 403 (1.9) 104% 99% (1.5) 100%/13%  17 93491 Peptone from broad bean  425 (10.2) 108% 99% (1.4) 96%/12% 18 93492 Peptone from wheat 427 (1.2) 110% 100% (2.2)  100%/13%  19 90765 Peptone from soybean,  408 (11.2) 108% 100% (2.3)  102%/18%  enzymatic digest 20 70178 Peptone from soybean, 401 (0.3) 104% 92% (2.3) 98%/14% enzymatic digest 21 S1674 Soy protein acid hydrolysate  432 (13.7) 109% 88% (1.3) 106%/18%  22 87972 Peptone from soybean, 400 (7.0) 102% 91% (0.6) 106%/21%  enzymatic digest 23 96174 Peptone from pea 404 (2.9) 104% 98% (1.3) 98%/10% 25 49760 GLUTEN HYDROLYSATE F. 432 (5.1) 111% 95% (2)   107%/16%  MAIZE 26 Ovalbumin 464 (4.9) 121% 99% (1.1) 97%/14% 27 Gelatin 475 (6.0) 124% 99% (1.7) 101%/16%  28 Bovine serum albumin 487 (8.1) 128% 100% (2.6)  104%/15%  29 PEG8000 (0.015%) 443 (1.8) 115% 98% (0.1) 104%/15%  Example 7 [0220] Extracts of plant proteins were prepared by suspending 2 g sample in 40 ml brine consisting of: 12% NaCl, 20 g/L NaAc anhydrous, 2.5 g/L NaH2PO4 anhydrous, and 10 g/L Na-benzoate in water, pH 5.4-5.8. After mixing for 2 hours on rotating device the suspension was centrifuged and the supernatant pH adjusted to 5.4-5.8 and filtered through a 0.45 μm syringe filter. The extracts were used for preparing formulations of CHY-MAX M by mixing with an exact measured and equal volume of a stock solution the enzyme to give samples having same concentration of enzyme proteins. In this example, extracts of 27 different plant proteins were tested in three groups with each group prepared on different days. [0221] The activity was measured one day after sample preparation; the column titled activity shown activity in IMCU/ml and relative to untreated control (no addition). Physical stability was tested according to example 3 with the only difference that in present example a different rotary device was used for vertical inversion of the samples (Multi RS-60 from Biosan at 32 rpm for 1 hour). The change in rotary device may have resulted in increased physical stress of the samples since retained activity of untreated sample was only 10% compared to ca. 70% in preceding examples. Samples were stored for 1 year at 5° C. and 37° C., respectively, and stability was tested during storage period. The column ‘End of storage’ shows remaining activity after 1 year—the number was calculated by fitting a single exponential function to all data points. [0000] TABLE 6 Activity of CHY-MAX ® M added different polypeptides. Activity index relative to untreated control (‘no addition’) is shown in percentage. Column ‘Retained Activity’ show retained activity of camel chymosin samples subjected to vertical inversion for 1 hr. Column ‘End of Storage’ show activity after storage at 5° C. and 37° C. Standard deviation is shown in parenthesis. Internal ref number: Group 1/EXP-14-AF3604. Activity Retained End of storage Compound IMCU/ml/Index activity (5° C./37° C.) No addition (only Brine)   405 (6.8) 100%  10% (1.4) 96%/22% 0.015% PEG 8000 481.9 (6.5) 119%  99% (3.1) 95%/21% 1 Nutralys F 85 F 450.4 (6)   111% 96% (1)  87%/17% (Roquette) 2 Nutralys F85G 421.6 (4.6) 104% 102% (0.5) 91%/20% (Roquette) 3 Nutralys F 85 M  419.9 (13.8) 104% 102% (0.9) 89%/10% (Roquette) 4 Nutralys S 85 F 415.2 (6.2) 103% 102% (0.2) 87%/19% (Roquette) 5 Nutralys W  461.3 (11.3) 114% 100% (0.4) 87%/14% (Roquette) 6 Solulys 048E  399.5 (12.4)  99% 103% (1)   94%/8%  (Roquette) 7 Solulys 095E 412.3 (2.6) 102% 100% (1.8) 91%/9%  (Roquette) 8 Tubermine Fv Proteine 403.4 (5.7) 100% 96% (0)  94%/15% De Pomme Des Terre (Roquette) 9 Tubermine GP Proteine   411 (3.3) 101%  90% (0.7) 95%/17% De Pomme Des Terre (Roquette) [0000] TABLE 7 Activity of CHY-MAX ®M added different polypeptides. Activity index relative to untreated control (‘no addition’) is shown in percentage. Column ‘Retained Activity’ show retained activity of camel chymosin samples subjected to vertical inversion for 1 hr. Column ‘End of Storage’ show activity after storage at 5° C. and 37° C. Standard deviation is shown in parenthesis. Internal ref number: Group 2/EXP-14-AF3604. Activity Retained End of storage Compound IMCU/ml/Index activity (5° C./37° C.) No addition (only Brine)  395.9 (10.8) 100%   7% (1.25) 93%/24% No addition (only Brine)   385 (3.7)  97%  7.5% (0.49) — No addition (only Brine) 396.3 (4.9) 100%  6.3% (0.54) — 0.015% PEG 8000 457.8 (5.6) 116% 98.9% (1.13) 99%/24% 10 Alburex E 361 G 511.1 (1)   129% 92.7% (0.84) 95%/21% (Roquette) 11 Gluten De Ble Supra 423.2 (2.2) 107%   90% (2.83) 92%/17% Vital (Roquette) 12 Lysamine GP Proteine  391.4 (13.6)  99% 77.3% (0.88) 95%/14% De Pois (Roquette) 13 Corn Gluten  359.1 (18.7)  91% 97.3% (0.28) 103%/22%  (Roquette) 14  rteprotein 440.4 (3.8) 111% 98.3% (1.36) 86%/19% (Naturdrogeriet A/S) 15 Sojaprotein   427 (1.1) 108% 106.8% (6.59)  88%/17% (Naturdrogeriet A/S) 16 Vegan Ris protein 352.4 (4.3)  89% 96.5% (2.22) 114%/28%  (Naturdrogeriet A/S) 17 Sojaprotein 437 (6) 110% 94.2% (2.41) 89%/18% Ketolyse A/S 18 Hamp protein complex 422.7 (3.2) 107% 98.2% (2.66) 100%/20%  økologisk (Nybogaard A/S) [0000] TABLE 8 Activity of CHY-MAX ® M added different polypeptides. Activity index relative to untreated control (‘no addition’) is shown in percentage. Column ‘Retained Activity’ show retained activity of camel chymosin samples subjected to vertical inversion for 1 hr. Column ‘End of Storage’ show activity after storage at 5° C. and 37° C. Standard deviation is shown in parenthesis. Internal ref number: Group 3/EXP-14-AF3604. Activity Retained End of storage Compound IMCU/ml/Index activity (5° C./37° C.) No addition (only Brine) 419.5 (1.1) 100%  8.8% (2.38) 97%/28% 0.015% PEG 8000 478.1 (2.9) 114% 102.8% (1.12)  100%/29%  19 Spirulina pulver økologisk 484.8 (9.4) 116%   97% (0.17) 57%/1%  (Dinsundhed.Net Aps) 20 Plant force rice protein 413.4 (5)    99% 87.5% (1.45) 96%/17% (Third Wave Nutrition) 21 Superfruict Hemp protein 447.8 (4.1) 107% 97.7% (1.81) 97%/20% (Superfruit Scandinavia AB) 22 Hampe protein økologisk 421.2 (1.3) 100% 101.2% (2.12)  98%/23% (Nybogaard A/S) 23 Plant force Rice protein 412.7 (9.8)  98% 84.1% (5.77) 99%/18% (Third Wave Nutrition) 24 Nutralys T 65 M 454.5 (8.5) 108% 100.1% (0.34)  88%/14% (Roquette) 25 LAB 4460 Nutralys PEA  451.9 (13.1) 108% 97.2% (0.1)  90%/19% XF EXP (Roquette) 26 LAB 4462 Nutralys PEA  436.8 (10.5) 104% 99.9% (0.45) 93%/16% BF EXP (Roquette) 27 Gluten De MAIS 58E 402.9 (0.5)  96% 65.5% (1.33) 97%/20% (Roquette) REFERENCES [0000] 1: EP2333056A1 (DSM, date of filing Dec. 4, 2007) 2: WO2012/127005A1 (DSM) 3: DE1492060A1 (Nordmark-Werke GmbH, published in 1969)

A liquid or dried granulated milk clotting aspartic protease enzyme composition comprising added polypeptides/proteins. The polypeptides/proteins may be animal-derived (e.g. whey, lactalbumin, transferrin, casein, ovalbumin, gelatin, blood), vegetable-derived (soy, pea, corn, potato, hemp, rice, wheat, peanut, sun flower, rape seed) or algae proteins (e.g. spirulina). Addition of protein in several instances increases activity of the enzyme and simultaneously improves physical stability.

BACKGROUND OF THE INVENTION The invention relates to a vehicle for beach cleaning comprising a vehicle frame, at least one wheel axis disposed on it, a vertically adjustable garbage pickup, a conveyor adjoining the garbage pickup and conveying the garbage taken over from the garbage pickup to a collecting receptacle, disposed at the rear end of the vehicle frame and a supply rotor allocated to the pickup area of the garbage pickup. Such a beach cleaning vehicle is known from U.S. Pat. No. 4,482,019. Refuse is picked up from the ground, e.g. a sandy beach, by a supply rotor designed with tines and conveyed to a conveyor belt. The tines of the supply rotor are bent in the direction of motion at their ends, the rotor rotates in the same direction. It is disadvantageous that the pollutants have to be picked up from the ground in the direction of motion and must be guided past the supply rotor over a range of 180°. Impurities flung away forwardly by the tines partly bounce against a rotor housing and partly fall back onto the beach; due to this they come in front of the supply rotor again and must be picked up again. The rotational speed of the rotor is added to the driving speed in the pickup area so that the refuse is tangentially flung forwardly in the direction of motion upon contact with the tines. In this fashion, pollutants can accumulate increasingly in front of the supply rotor and impair a further use. The tines are greatly loaded when striking against the pollutants or the sand due to the high relative speed, and they may break. Fibrous pollutants such as algae can wind themselves around the supply rotor and the tines due to the rotation of the supply rotor and the long entrainment up to the delivery to the transport belt and are matted together with it. In the case of greater algae pollution the known supply rotor must be cleaned frequently and freed from the algae. Due to the design of the supply rotor and its allocation to the transport belt, pollutants are only picked up from the beach, which are seized by the rotor. Pollutants not picked up by the supply rotor cannot be picked up by the transport belt and remain on the beach. The entire vehicle frame with all means attached thereto is lowered for the vertical adjustment of the supply rotor. The wheels mounted on a strap-shaped mounting are pivoted rearwardly by an actuating means, and due to this the entire vehicle is lowered. A vertical adjustment of the supply rotor relative to the transport belt is not possible. The distance between supply rotor and transport belt can likewise not be varied. Bulky pollutants cannot be picked up, and lead possibly to a damage to the vehicle. A separation of pollutants and sand only takes place in the known beach vehicle by means of a sieve belt connected downstream of the transport belt. It must transport both the pollutants and the sand. This can in particular greatly load the vehicle in terms of weight, in particular if the sand is moist. Part of the sand with the pollutants is moreover further transported up to the collecting receptacle. The collecting receptacle is filled prematurely and must be exchanged for another receptacle or be emptied. SUMMARY OF THE INVENTION The invention is based on the object of providing a vehicle for beach cleaning of the type mentioned at the beginning which is improved as regards the supply, pickup and transport of refuse and the separation of the refuse and sand and the disposal of the pollutants. This object is attained in a vehicle for beach cleaning having the features of the preamble of claim 1 by the fact that a swivel frame supporting the garbage pickup and the supply rotor is mounted in lowerable fashion on the vehicle frame for the vertical adjustment, the supply rotor is pivotably mounted on it by means of links across a swivelling range and is in particular rotatable counter-clockwise about an axis of rotation mounted on the links. The supply rotor is disposed in a first, front operating position for the supply of garbage and/or sand to the garbage pickup in the direction of motion in front of the pickup V-ledge disposed in front of the garbage pickup, the distance between the V-ledge and the axis of rotation of the rotor is minimal in a second, central operating position, and the rotor is disposed at a distance to the V-ledge or the garbage pickup which is greater as compared with the second operating position in a third, rear operating position. Consequently not the entire vehicle frame must be lowered according to the invention for the vertical adjustment of the garbage pickup, but only the swivel frame. Depending upon the application, the garbage pickup is lowered with the pickup V-ledge to the sand or into the sand. The pollutants and, possibly, sand are picked up via the V-ledge. The supply rotor is also lowered at the same time. Since it is mounted pivotably relative to the garbage pickup, both the distance of the supply rotor to the garbage pickup or the V-ledge and the height of the supply rotor relative to the sand can be varied indepedently of the garbage pickup. The supply rotor is disposed in the direction of motion in front to the V-ledge, and thus also in front of the garbage pickup in a first operating position. If the V-ledge rests approximately on the sand in this position, the supply rotor rotates above the sand or penetrates only somewhat into the sand surface. The garbage pickup supplies all superficial pollutants to the garbage pickup in this position. Only a very small sand capture takes place, and a high driving speed is consequently possible. Since the rotor rotates moreover counter-clockwise, rotational speed and driving speed are not added, which leads to a lesser load of the rotor. The rotor flings the pollutants in the direction of the V-ledge and the garbage pickup, a partial separation of pollutants as a function of their weight taking place at the same time. More light-weight pollutants are flung over a greater distance in the direction of the garbage pickup than heavier ones, e.g. sand. Impurities possibly not seized by the supply rotor are subsequently still picked up by the V-ledge and conveyed to the garbage pickup. In this fashion, all pollutants are picked up from the beach up to a certain penetration depth and the beach is thoroughly cleaned. The first operating position is in particular of advantage in the case of wet sand or in the flood border area, since only little sand pickup takes place and the surface is thoroughly cleaned. The second operating position of the supply rotor is preferably used for dry sand. In this position the rotor does not only serve for supplying pollutants to the garbage pickup, but also for accelerating the sand and the pollutants picked up by the V-ledge. The V-ledge is partly immersed in the sand. The supply rotor forming a duct with the V-ledge catches partly the sand and in particular the garbage lying on the surface of the sand. In similar fashion as in the first operating position, the rotor flings the materials located in its area of rotation in the direction of the garbage pickup. The lighter parts are flung over a greater distance than the heavier parts. In this fashion, sand and pollutants are already supplied to the garbage pickup in partly separated fashion and can more easily be separated still further on it. At the same time, a higher driving speed is possible due to the accelerated conveying of the picked up materials. It is in particular possible in the third operating position to also pick up bulky parts. Since the distance between supply rotor and V-ledge or garbage pickup is relatively great, the parts picked up by the V-ledge can be guided to the garbage pickup through the gap formed between rotor and V-ledge. Due to its rotation, the rotor promotes the further transport. The pollutants largely already separated from the sand by the supply rotor and the garbage pickup are freed from sand possibly entrained almost completely on the subsequent conveyor and supplied to the collecting receptacle. The features of claims 2 and 3 are furthermore advantageous, since in this fashion the swivel frame is of a simple design and is disposed completely below the vehicle frame. The upper side of the vehicle frame can be additionally used for many purposes, such as for the transporting of building material, earth, gardening articles or the like. The swivel frame itself can be lowered with its end located in the direction of motion due to the mounting on its rear end. Supply rotor and pickup V-ledge are disposed on said end. The features of claims 4 and 5 are advantageous since a multi-purpose use of the vehicle is possible in this fashion. The swivel frame together with garbage pickup and supply rotor can be exchanged for another swivel frame with corresponding means by means of detachable quick-action closures. A retrofitting of the vehicle to other fields of application is possible without great time expenditure. The flexibility of the vehicle is increased by this. A use for cleaning asphalted roads is e.g. also possible, the pickup V-ledge being preferably designed elastically and the supply rotor being particularly designed as brush roller in this case. The vehicle can also be used without swivel frame for general transport purposes. The features of claims 6 to 9 are also advantageous, since the garbage pickup can be used for many fields of application in this fashion. The pollutants are taken over from the supply rotor or the V-ledge by the elevator and are conveyed to the conveyor connected downstream. If the elevator has a drive of its own, its speed can be adjusted independently of the rotational speed of the supply rotor or of the speed of the conveyor and can be easily adapted to applications with different garbage volumes. The design of the vehicle according to claims 10 to 12 is also advantageous. The pickup area of V-ledge, supply rotor and garbage pickup can be designed in accordance with the vehicle width. The width of the flow of garbage is reduced in accordance with the given conditions via the disposed lateral blades and directing plates and can thus be passed through between the wheels attached to the wheel axis. The pollutants are picked up before they are possibly compacted with the wheels of the vehicle or even pressed into the ground, and the sand is cleaned across the entire width of the vehicle. A larger width of e.g. the V-ledge would basically also be possible, however, this would render the handling of the vehicle more difficult and persons might be injured due to the ends of the V-ledge laterally projecting from the contour of the vehicle. The features of claims 13 and 14 are advantageous inasmuch as e.g. an automatically controlled lowering and lifting of the swivel frame is possible by means of the actuating means. The actuating means may be designed as a hydraulic actuating cylinder and can e.g. be remotely controlled by the driver of the vehicle. In order to be able to use the entire width of the swivel frame for the garbage pickup, the actuating means is disposed laterally on the frame. It is furthermore advantageous if the angle of incidence for the garbage pickup of the pickup V-ledge relative to the ground is greater than the angle of incidence of the garbage pickup. In this fashion a narrowing transport duct is obtained between pickup V-ledge and supply rotor in the second operating position for the further transport of picked up garbage and sand, the end of the transport duct having a larger aperture angle so that the material picked up due to this can be distributed better across the garbage pickup. A further development of the vehicle according to claims 16 to 18 is furthermore suitable. Material possibly flung upwardly or potentially beyond the garbage pickup by the rotor is recovered and deflected back into the garbage pickup by means of the baffle lining. At the same time, lumps are e.g. comminuted during the impact, which renders a subsequent separation of garbage and sand easier on the garbage pickup or the conveyor. The height of the baffle lining decreasing in particular oppositely to the direction of motion prevents that garbage or sand is flung away beyond the garbage pickup. The covering of the baffle lining serves additionally as a stop during the swivelling back of the swivel frame in the direction of the vehicle frame and for mounting the swivel axis of the rotor. Advantageous developments of a supply rotor suspension are revealed by claims 19 to 21. Due to the use of the U-shaped frame, the supply rotor is suspended by means of the frame fundamentally in pendulous fashion. The entire frame can be pivoted about the swivel axis by means of the flange bearing projecting from the U-web and the corresponding bearing straps projecting from the covering. The rotor is thus suspended easily accessibly. A pivoting across the swivelling range comprising the operating positions is moreover possible in a very simple fashion due to the arrangement of the flange bearings and bearing straps. The swivel radius of the supply rotor is relatively large, but nevertheless it is possible to pivot the swivel frame up to close to the vehicle frame, flange bearings and bearing strips of the rotor being disposed laterally next to the vehicle frame. A vertical fine adjustment of the rotor is moreover possible thanks to the special mounting of the axis of rotation of the rotor. In order to adjust the supply rotor independently of other means in its rotational speed it is furthermore advantageous if a driving means is allocated to one end of the axis of rotation of the rotor. This may be a hydromotor which is connected to the hydraulic system of the vehicle and can possibly be adjusted by the driver. The features of claims 23 and 24 are also advantageous, since the rotor can be pivoted independently of the garbage pickup due to the actuating means for pivoting the rotor. The actuating means can e.g. be designed as a hydraulically operable piston. The actuating means is attached with one end near the axis of rotation of the rotor so that no greater leverage occurs. In order to render the pivoting easier, the other end of the actuating means is disposed on a side wall of the baffle lining. The supply rotor comprises a plurality of radially projecting tines defining the rotor circumference in an advantageous embodiment. The pollutants or the sand are flung in the direction of the V-ledge or the garbage pickup by means of the tines. The tines can be designed as elastic tines of metal or plastic material fixedly disposed on the axis of rotation of the rotor. It is likewise possible to mount the tines in spring-loaded fashion. In order to achieve a minimum distance between V-ledge and axis of rotation of the rotor in the second operating condition and to optimize the transport effect of the rotor in this position it is advantageous if the pickup V-ledge extends substantially in a direction in parallel to a tangent of a swivel curve in the direction of motion, the swivel curve being defined as envelope of a part of the rotor circumference opposite to the swivel bearing. Advantageous developments of supply rotor and V-ledge result from the features of claims 27 to 30. The features of claims 31 and 32 are advantageous inasmuch as an additional separation of the garbage from the entrained ground materials is possible by means of the conveyor. In order to prevent a soiling of or damage to the wheel axis and all lines located below the conveyor means, the installation of a baffle plate above the rear axle is advantageous. A deflection axis can be formed as an unbalanced shaft on the conveyor but also on the garbage pick up and facilitate the shaking off of sand or ground material by a specific vibrating movement vertically to the direction of transport. It is advantageous for mounting the actuating means of the swivel frame if the front transverse bar of the vehicle frame projects laterally beyond the transverse bars up to about the width of the vehicle and the actuating means are mounted on its ends. At the same time, tipping means for a loading area disposed on the vehicle frame can be mounted on these ends. The vehicle frame is substantially formed by a frame rectangle formed by two longitudinal bars and two transverse bars and a frame triangle disposed on its front edge in one example of embodiment. A coupling means for a traction vehicle is disposed on the tip of the triangle. In order to obtain a loading area being as large as possible, it is advantageous if the loading area extends almost completely across garbage pickup and conveyor. The collecting receptacle is pivotable across the loading area by means of two supports disposed laterally on the vehicle frame or on the loading area and can be emptied uniformly on the loading area. The features of claims 35 to 37 are moreover advantageous inasmuch as a uniform dumping of the collecting receptacle across the entire length of the loading area is possible by means of the tipping connecting bars. The first garbage is directly emptied above the rear end of the loading area on the same via a dumping edge of the collecting receptacle, and the collecting receptacle is gradually further pivoted during the pivoting towards the front end of the loading area by means of the arrangement of tipping links and supports. The support of the collecting receptacle can be rotated from a substantially horizontal position into an approximately vertical position by means of a tipping means. Both the tipping means for the collecting receptacle and the tipping means for the loading area can be designed as hydraulically operable pistons. The further development of the vehicle according to claims 38 to 40 is furthermore suitable. A vertical adjustment of the rear end of the vehicle is possible due to the wheel axis designed as a lift axis. The vehicle frame is lifted by means of the lifting means in particular for emptying the loading area, and the collecting garbage can also be dumped into a higher container. BRIEF DESCRIPTION OF THE DRAWINGS The solutions suggested according to the invention and advantageous examples of embodiment thereof are explained and described in the following by means of the Figs. represented in the drawing. FIG. 1 shows a lateral view of the vehicle for beach cleaning with pivoted loading area and collecting receptacle. FIG. 2 shows a lateral view of the vehicle for beach cleaning with lowered swivel frame. FIG. 3 shows a top view of the vehicle. FIG. 4 shows a top view of garbage pickup and conveyor. FIG. 5 shows a front view of the supply rotor. FIG. 6 shows a lateral view of a frame for mounting the supply rotor. FIG. 7 shows a lateral view of a driving means of the supply rotor. FIG. 8 shows a lateral view of a first operating position of the supply rotor. FIG. 9 shows a lateral view of a second operating position of the supply rotor. FIG. 10 shows a lateral view of a third operating position of the supply rotor. FIG. 11 shows a front view of a lift axis according to the invention. FIG. 12 shows a lateral view of the lift axis and FIG. 13 shows a further lateral view of the lift axis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The vehicle for beaching cleaning 1 according to the invention is represented in FIG. 1 together with a traction vehicle 2. The beach cleaning vehicle 1 is connected to the traction vehicle 2 by means of a coupling means 3 and a coupling means 77 formed on the traction vehicle 2 and movable across the ground 68. The vehicle 1 is substantially formed of the vehicle frame 4, an upwardly folded loading area 5, a swivel frame 7 disposed below the vehicle frame 4 and a collecting receptacle 6 pivoted across the loading area 5. The coupling means 3 is disposed on the vehicle frame 4 on its front end, and a substantially horizontal tipping axis 51 for the loading area 5 is disposed on its rear end. The loading area 5 is upwardly tilted about the tipping axis 51 by about 45° with respect to the vehicle frame 4. An adjustable rear wall 50, which is pivotably mounted on the rear upper end of the loading area 5 is partly opened. A collecting receptacle pivoting means 39 is disposed on a side wall 87 of the loading area near the lower side pointing towards the vehicle frame. The same extends substantially in parallel and closely adjacent to the lower side of the side surface 87. The pivoting means 39 is mounted on a front end 40 on the side surface 87, while the rear end 41 is mounted on the tip of a triangular frame element 48, 49. The ends of the legs 48 and 49 of the triangular frame element are connected with the support 42. The support and the legs of the triangle close a substantially equilateral triangle. Near the connection between the legs of the triangle 48 and the support 42, the support 42 is pivotably mounted with its end 43 on the lower side of the lateral wall 87 of the loading area 5. The collecting receptacle 6 is pivotably mounted relative to the support 42 on the opposite end 44. The end 44 of the support 42 is disposed approximately in the surface centroid of a lateral surface of the collecting receptacle 6. A transverse bar 45 extends rectangularly to the support 42 along the collecting receptacle 6. A tipping link 46 is rotatably mounted adjacent to the end 43 of the support 42 on the side wall 87 of the loading area 5. The bearing point 164 of the tipping link 46 is represented in FIG. 2 or 3 and is located staggeredly in the direction of the upper edge of the lateral wall 87 relative to the bearing point 43 of the support 42. The tipping link 46 is rotatably mounted on the upper end 47 on the collecting receptacle 6. The position of the link mounted 47 on the collecting receptacle is approximately at the intersection of the top surface of the collecting receptacle and a straight line running from the bottom surface of the receptacle to the top surface of the receptacle, which line passes through the mounting location 44 of the receptacle 6 and the support 42. The tipping link 46 is designed with a length being somewhat smaller than that of the support 42. The loading area 5 is pivoted with respect to the vehicle frame 4 by means of a loading area tipping means 36 which is disposed between a transverse bar 35 of the frame 4 and the lateral surface 87 of the loading area 5. The tipping means 36 is rotatably mounted on the transverse bar 35 with one end 37 and is disposed approximately above the end 43 of the support 42 centrally to the side wall 87 with the other end 38. An actuating means 32 is rotatable mounted with one end 34 on the transverse bar 35 opposite to the end 37 of the tipping means 36. The actuating means 32 is rotatably mounted with its other end 33 on a swivel frame 7 disposed below the vehicle frame 4. The swivel frame (7) consists essentially of longitudinal bars forming a rectangle and at least one transverse bar. The rear end of the swivel frame is rotatably mounted on the vehicle frame. The swivel frame 7 can be lowered in the direction towards the ground 68 by means of a substantially horizontal swivel axis 8 disposed near the rear end of the swivel frame by means of the actuating means 32. A number of rollers 20, 21, 24, 25, 26, 27 are rotatably mounted in the swivel frame 7. The rollers 20 and 21 serve as deflecting axes for a conveyor belt formed of an upper run 22 and lower run 23. The rollers 24, 25 and 26 are designed as supporting rollers and define a transport plane of the upper run 22 together with the deflecting axes 20 and 21. The rollers 27 and 28 are in each case disposed between the deflecting axes 20 or 21 and the supporting rollers 24 or 26 adjacent to them. They are downwardly staggered with respect to these rollers and not in contact with the upper run 22. The rollers 27 and 28 serve as tensioning rollers and are disposed below the lower run 23 and guide it in the direction of the upper run 22. The lower run 23 sags in the direction of the ground 68 between the tensioning rollers 27 and 28. A baffle lining 15, which is a cover for the swivel frame 7 is adjacently disposed downstream of the supply rotor 11. The baffle lining consists of two lateral walls 134 and a covering 16, that extends between and connects the walls 134 at their upper ends. The baffle lining 15 is disposed on the swivel frame 7 above the deflecting axis 20 and the supporting roller 24. The baffle lining 15 points from the swivel frame 7 in the direction of the vehicle frame 4. In the pivoted condition of the swivel arm 7 represented in FIG. 1 a covering 16 of the baffle lining 15 is in abutment with the lower side of the vehicle frame 4 across its entire length. The end 33 of the actuating means 32 is disposed at the rear end of the baffle lining 15 near the swivel frame 7. A directing plate 65 is disposed between the swivel axis 33 and the end 8 of the swivel frame 7 mounted on the vehicle frame 4, which extends in the longitudinal direction of the swivel frame projecting beyond the upper run 22. An actuating means 29 extends between a rear upper edge of the baffle lining 15 and a supply rotor 11 disposed before it for pivoting the rotor. It is mounted with its rear end 31 on the baffle lining 15 and with its front end 30 on the supply rotor 11. The supply rotor 11 is rotatable about an axis of rotation. It has a plurality of radially projecting tines 67, wherein the tines may be spring tines. For example, the supply rotor may take the form of a brush roller or other conventional supply rotor. A driving means covering 17 extends between axis of rotation 18 and the vehicle frame 4. It projects partly laterally beyond the vehicle frame 4. A bearing strap 19 is directed towards the upper end of the covering 17. The bearing strap is disposed on a front edge of the covering 16 of the baffle lining 15. In extension of the swivel frame 7 a lateral blade 64 partly laterally covering the supply rotor 11 is directly disposed below the supply rotor 11. The height of the lateral blade 64 corresponds approximately to the height of the end of the swivel frame 7, which is adjacent to it. While the swivel frame 7 encloses an acute angle with the vehicle frame 4 and points in the direction of the ground 68, the side blade 64 points in the direction of the traction vehicle 2 and somewhat upwardly, extending approximately in parallel to the opposite end of the swivel frame 7 pointing towards a conveyor 12. The conveyor 12 is disposed between wheel axis 13 and vehicle frame 4. It has an inclination corresponding approximately to the swivel frame. A run 58 formed of upper run and lower run runs over deflecting axes 52 and 53 and over supporting rollers 54 and 55 and tensioning rollers 56 and 57. The direction of transport of the conveyor 12 and of the garbage pickup 9 disposed in the swivel frame 7 is the same and directed towards the rear end of the vehicle 1. The conveyor 12 also has laterally limiting directing plates 66 in similar fashion as the swivel frame 7. A vertically adjustable garbage pickup is disposed below the vehicle frame 4. The garbage pickup includes an elevator with a front deflection axis 20 at the front end of the swivel frame 7 and a rear deflection axis 21 at the rear end of the swivel frame. The swivel frame 7 with the supply rotor 11 and the garbage pickup can be designed as a quickly exchangeable cassette unit. The vehicle frame 4 is represented in lifted fashion with respect to the wheel axis 13 in FIG. 1. Two supporting arms 62 and 63 connected with the vehicle frame point from the vehicle frame in the direction of the wheel axis 13. A lifting cylinder 61 is disposed centrally between them. A lifting piston 60 is extended out of the lifting cylinder 61 almost completely, a holding element 59 partly encompassing the wheel axis 13 being disposed on its end. The holding element has a cross-section similar to an isosceles triangle. The lifting piston 60 is centrally connected to the base of this triangle. The wheel 14 is almost completely visible when the vehicle frame 4 is lifted by means of the lifting means 60, 61. A vertically adjustable actuating wheel 162 for depositing the vehicle 1 is disposed near the coupling means 3 vertically to the vehicle frame 4. The beach cleaning vehicle 1 with the swivel frame 7 lowered to the ground 68 is represented in FIG. 2. The same elements are provided with the same reference numerals in accordance with FIG. 1 and will only be partly mentioned. In this Fig. the loading area 5 is placed on the vehicle frame. The tipping means 36 moves its end 38 along the circular arc 72 when being actuated, the loading area 5 adopting approximately the position represented in FIG. 1 at the end of the circular arc. The tip 41 of the triangular frame part can be guided along the semi-circular arc 71 by means of the collecting receptacle swivel means 39. Whereas the collecting receptacle is pivoted as far beyond the loading area 5 as possible and the tip of the triangle 41 points in the direction of the swivel means 39 in the position of the collecting receptacle 6 shown in FIG. 1, the collecting receptacle 6 is disposed near the ground 68 below the rear deflecting axis 53 of the conveyor 12 in the position represented in FIG. 2. Upon actuation of the collecting receptacle swivel means 39, the surface centre 44 of the collecting receptacle 6 moves along the circle 69 up to the position of the collecting receptacle 6'. The end point 47 of the tipping link 46 moves at the same time along the arc 70. Due to the relative arrangement and length of support 42 and tipping link 46 described in FIG. 1, the corresponding guide arcs 69 and 70 intersect each other, and the collecting receptacle 6 points with its open end more and more in the direction of the loading surface 5 and can be emptied via a dumping edge 161 in the direction of the loading area 5. The swivel frame 7 is lowered about the bearing point 8 with one end to the ground 68. A pickup V-ledge 10 disposed on the swivel frame 7 below the supply rotor contacts the ground 68 with its free end and the lateral blade 64 extends with its lower side substantially in parallel to the ground. Upon the lifting of the swivel frame 7 in the direction towards the vehicle frame 4 by means of the actuating means 32, its end 33 mounted on the swivel frame 7 can be guided along the arc 73. The axis of rotation 18 of the supply rotor 11 can furthermore be pivoted across the swivel range 74 by means of the actuating means 29. The supply rotor is in a second operating position in the arrangement of the supply rotor represented in FIG. 2, while the positions 11' and 11" correspond to a first or a third operating position. They will be explained in greater detail in FIGS. 8 to 10. As opposed to the representation of the vehicle frame 4 lifted in FIG. 1, the wheel axis 13 is mounted directly on the ends of the supporting arms 62 and 63 and the vehicle frame extends substantially horizontally. A top view of the beach cleaning vehicle 1 is shown in FIG. 3. The vehicle frame 4 has a triangular frame section and an adjoining rectangular frame section connected with the coupling means 3. The triangular frame section is formed by two supports 81 and 82 extending symmetrically to the longitudinal direction 100 from the coupling means 3 in the direction of a first transverse bar 35. The tip of the triangle is disposed in the coupling means 3, while the base of the triangle is formed by the transverse bar 35. Longitudinal bars 75 and 76 adjoin the supports 81 and 82 in parallel to the longitudinal axis 100. The rectangular frame section is formed by these supports the transverse bar 35 and a transverse bar 78 disposed near the end of the vehicle. The longitudinal bars 75 and 76 have a distance corresponding to the distance of the wheels 14 and 14'. The loading area 5 is pivotably mounted on its rear ends 51 and 51', these ends projecting rearwardly beyond the transverse bar 78. While the transverse bar 78 extends from one longitudinal bar to the other, the transverse bar 35 being in parallel to it has a greater length. It projects with its ends 79 and 80 on both sides beyond the longitudinal bars by respectively the same length. The actuating means 32 and 36 are pivotably mounted on the outer ends of the transverse bar ends 79 and 80. The loading area 5 is disposed above the frame 4 and is resting on it. A front wall 88, two side walls 87 and 89 and a rear wall 50 of the loading area 5 can be recognized in the top view shown in FIG. 3. The side walls or the front and rear wall are in parallel to the longitudinal bars 75 and 76 or the transverse bars 35 and 78 and form the rectangular loading area 5. The rear wall 50 extends at an angle to the vertical rearwardly in the direction towards the collecting receptacle 6 in accordance with the representation in FIG. 2. Whereas the upper edge of the rear wall 50 is disposed in front of the collecting receptacle, the lower edge which is closer to the collecting receptacle is disposed above an opening 90 of the collecting receptacle 6. The dumping edge 161 is thus located below the loading area 5. Dumping edge and the side of the collecting receptacle opposite to it extend substantially in parallel to the rear wall 50. The extension of the collecting receptacle 6 vertically to the longitudinal direction 100, i.e. its width, is slightly shorter than the inner distance of the side walls 87 and 89 of the loading area. The collecting receptacle 6 is centrally connected with the support 42 or 42' or the tipping links 46 and 46' with its transverse sides via the bearings 44 and 44' or 47 and 47'. The supports 42 and 42' extend in parallel to the tipping links 46 and 46' outside the side walls 87 and 89. Both supports 42 and tipping link 46 are connected 20 on their ends 43 and 164 with the side wall 87 and correspondingly with the side wall 89 on the other side. Laterally outside and in parallel to the side walls 87 and 89, collecting receptacle swivel means 39 and 39' are disposed on the side walls 87 and 89. The swivel means 39 extends between a first bearing point 40 and a second bearing point 41. The bearing point 41 is disposed above the support 42 in accordance with FIGS. 1 and 3 as tip of a triangle. The distance of support 42 and collecting receptacle swivel means 39 to the side wall 87 is substantially the same. The same applies mutatis mutandis to the collecting receptacle swivel means 39' on the other side wall 89 of the loading area 5. A hydraulic covering 91 is disposed in front of the front wall 88 on the triangular frame section formed by the supports 81 and 82. The hydraulic covering extends symmetrically to the longitudinal direction 100, its side surfaces extending substantially in parallel to the supports 81 and 82 and projecting beyond them. The covering 16 is disposed symmetrically to the longitudinal direction 100 below the hydraulic covering 91 and below the frame 4. The covering 16 projects slightly on both sides relative to the side walls 87 and 89 of the loading area 5, the actuating means 29 and 29' being disposed on these sides. The distance of these actuating means corresponds substantially to the distance of the collecting receptacle swivel means 39 and 39' or the distance of the supports 42 and 42'. Bearing straps 19 and 19' are disposed on the front end of the covering 16 symmetrically to the longitudinal direction 100. The bearing straps are in engagement with bearing means 85 and 86 of a frame 84. The frame 84 extends in parallel to the front side of the covering 16 and laterally projects beyond it by two arms directed in the direction of the actuating means 29 and 29'. The driving means covering 17 is disposed on one side of the frame 84, a motor 83 projecting from the covering 17 in the direction of the longitudinal axis of the frame 84. The beach cleaning vehicle 1 is represented in FIG. 4 in a top view of the garbage pickup 9, the conveyor 12 and the collecting receptacle 6. Both the run 22 of the garbage pickup 9 and the run of the conveyor 12 are designed as sieve belts. They have a plurality of substantially rhombic openings. Two lateral blades 64 and 64' outwardly bent symmetrically to the longitudinal direction 100 are disposed on the front side of the vehicle 1 on the ends of the V-ledge 10. The pickup width 92 of the lateral blades 64 and 64' corresponds substantially to the vehicle width 93. The V-ledge 10 projects from the garbage pickup 9 approximately beyond half of the longitudinal extension of the lateral blades 64 and 64' in the direction of the coupling means 3. The distance of the lateral blades is slightly smaller at the rear ends of the lateral blades than the width 95 of the upper run 22 of the garbage pickup 9. Directing plates 96 and 97 extending symmetrically to the longitudinal direction 100 adjoin these ends. They extend across a section directly adjoining the lateral blades 64 and 64' in parallel to the longitudinal direction 100, while they converge towards each other in the subsequent section. The distance of the directing plates 96 and 97 is somewhat smaller at the end of the garbage pickup 9 than the width 94 of the run 58 of the conveyor 12. The conveyor is disposed with its front deflection axis 52 below the rear deflection axis 21 of the garbage pickup in accordance e.g. with FIG. 1. The directing plates 96 and 97 are continued by parallel directing plates 66 and 66' of the conveyor up to its rear end. The collecting receptacle 6 is disposed on this end with a width 102, this width being greater than the width 94 of the upper run 58 of the conveyor 12. A drive means 98 is disposed on one side of the rear deflection axis 21 for driving the garbage pickup 9. At least the supporting rollers 25 and 26 are drive-connected with the deflection axis 21 by means of driving connections 99. The conveyor 12 also has a driven means 101 disposed on one side on its rear deflection axis 53. Since the conveyor 12 is disposed between the wheels 14 and 14' above the wheel axis 13, its width 94 is smaller than the inner distance of the two wheels. The supply rotor 11 is represented in FIG. 5. The frame 84 is substantially of a U-shape. A U-web 103 extends horizontally and in parallel to the swivel axis 120 of the rotor or the axis of rotation 18 of the rotor. The U-web 103 has U-legs 104 and 105 disposed rectangularly to it on its ends. They extend up to near above a rotor shaft 106 concentric to the axis of rotation 18. Bearing flanges 107 or 108 are disposed on the ends 109 and 110 of the U-legs 104 and 105. The bearing flanges are placed from the outside on the U-legs 104 or 105 and connected with them. The axis of rotation 18 is mounted in the bearing flanges 107 and 108. Concentric rotor end disks 132 and 133 are disposed on the axis of rotation 18. The rotor end disks limit the supply rotor 11 in the direction of the axis of rotation. A plurality of radially projecting tines 67 are disposed on the rotor shaft 106. Only a few tines are represented in FIG. 5 in order to illustrate this. Bearing means 85 and 86 are disposed on the U-web 103 to mount the supply rotor 11 on the swivel axis 120. The bearing means are formed in each case by a pair of bearing flanges 116, 117 or 118, 119. The bearing flanges have a corresponding opening to receive the swivel axis. A drive means 111 is disposed on one side of the supply rotor 11. The drive means 111 comprises a motor 112 disposed above the U-web 103 and a drive disk 113 mounted on its driving axis. The drive disk 113 is connected with a drive disk 114 coaxially disposed on the axis of rotation via a V-belt 115. A lateral view in particular of the flange bearing 108 is represented in FIG. 6. It is substantially of a U-shape. Oblong holes 123 and 124 are disposed in the U-webs symmetrically to an oblong groove 122 receiving the axis of rotation. A U-leg has an enlargement, in which a bore 30 is disposed. One end of the actuating means 29 can be mounted in this bore. A U-leg 105 of the frame 84 of FIG. 5 is visible above the bearing flange 108. Both the oblong groove 122 and the U-leg 105 extend vertically in the direction 125. The bearing flange 119 extends at the upper end of the U-leg 105 in the direction 126. The bearing flange has a swivel bearing bore 121. The angle 127 is enclosed between the direction 125 of the oblong groove 122 and the direction 126 of the bearing flange 119. The driving means of the supply rotor 11 is represented in FIG. 7. The rotor end disk 133 is disposed concentrically to the axis of rotation 18. Tines 67 project radially beyond the rotor end disk and define the circumferential line upon rotation in the direction 128. The drive disk 114 is connected with the axis of rotation 18 coaxially to the axis of rotation 18. The drive disk 113 connected with the motor is disposed vertically above this drive disk. Both are drive-connected via a V-belt. A tensioning roller 131 staggered laterally with respect to the connecting line of the two drive disks 113 and 114 is disposed between the drive disks 113 and 114 to tension the V-belt. The supply rotor is represented in a first operating position in FIG. 8. The same reference numerals designate the same elements as they are already known from the preceding Figs. They will only be dealt with partly. The supply rotor 11 is pivoted forwardly about the swivel bearing axis 120 by means of the actuating means 29. The lowest point of the supply rotor 11 is located near the surface 68 and in front of the pickup V-ledge 10. The tines 67 engage in a layer of garbage 136 located on the surface upon counter-clockwise rotation 128. The garbage 136 is conveyed to the upper run 22 of the garbage pickup via the pickup V-ledge both by the rotation of the supply rotor 11 and by the movement of the vehicle in the direction 140. The garbage pickup transports the garbage away in the direction 137. In the operating position shown in FIG. 8 the pickup V-ledge 10 is disposed near the surface 68, but above this surface. The supply rotor can be pivoted forwardly that much by means of the actuating means 29 until the length of the piston 138 corresponds approximately to the length of the actuating means 29. In the position of the supply rotor being pivoted rearwardly to the greatest extent, the piston 138 is completely pulled into the actuating means 29. The entire swivel range of the supply rotor corresponds substantially to the swivel arc 74 of the axis of rotation 18. A vertical fine adjustment of the axis of rotation 1B in directions 141 is possible by means of the oblong holes 123 represented in FIG. 6. A wedge-shaped recess 139 is disposed in a lateral wall 134 of the baffle lining 15. It serves for receiving the axis of rotation 18 upon the pivoting of the supply rotor 11. In the operating position represented in FIG. 8 the tines 67 do not engage into the sand 135 located below the surface 68. Distance a, as seen in FIG. 9, is measured by forming a right angle between a substantially vertical line from the swivel bearing 120 to the ground surface and a substantially horizontal line from the tip 144 of the V-ledge 10, wherein a is equal to the distance between the tip of the V-ledge and the base point of the right angle. The distance a should be less than or equal to 1.5 r, wherein r is the radius of the rotor 131, and greater than or equal to 0.8 r, preferably a is approximately 1.15 r. Distance b is the distance of the swivel bearing 120 from the horizontal line measured by a. The distance b is less than or equal to 3.0 r and greater than or equal to 2.0 r, preferably b is approximately 2.4 r. Distance c, the distance between the swivel bearing and the plane determined by the V-ledge is less than or equal to 3.2 r and greater than or equal to 2.5 r, preferably c is approximately to 2.8 r. Distance e is the distance between the periphery of the supply rotor and the plane determined by the V-ledge. A second operating position of the supply rotor 11 is represented in FIG. 9. The pickup V-ledge is introduced with its tip 144 into the sand up to the depth d in this case. Both sand 135 and garbage 136 is located between the pickup V-ledge 10 and the supply rotor 11. The supply rotor 11 is pivoted rearwardly that much in this operating position that the distance e between the circumferential line 129 and the V-ledge 10 is minimal. Further characteristic magnitudes according to the invention are the distance a of the tip 144 of the pickup V-ledge 10 and the perpendicular base point 143 of the perpendicular 142 passing through the swivel axis 120 and the distance b or c of the swivel axis 120 from the perpendicular base point or the plane formed by the pickup V-ledge 10. The pickup V-ledge encloses an angle α with the horizontal, which is greater by the angle 145 than the angle β enclosed between upper run 22 and the horizontal. Distance e is about 1/4 to about 1/6 of the radius of the rotor. The supply rotor 11 is represented in a third operating position in FIG. 10. The piston 138 is completely introduced into the actuating means 29 and the supply rotor is disposed in its position pivoted rearwardly to the greatest extent. The circumferential line 129 of the supply rotor almost contacts the covering 16 from below and the axis of rotation 18 is introduced as far as possible into the cutout 139 of the side wall of the baffle lining. Circumferential line 129 and upper run 22 are disposed at the distance f in the third operating position. The distance f is approximately twice as great as the distance e between circumferential line and pickup V-ledge 10 in the second operating position. As can be recognized by means of the envelope 163 of the circumferential line 129 during pivoting, the distance e is the minimum distance. A front view of the wheel axis 13 is represented in FIG. 11. A bottom wall 146 of the loading area 5 extends horizontally and rests on the transverse bar 78 of the vehicle frame. The vehicle frame is laterally enclosed by the longitudinal bars 75 and 76. The side walls 82 and 87 enclosing the loading area 5 in vertical direction are disposed above the longitudinal bars 75, 76 and outwardly staggered with respect to them. Lifting cylinders 61 or 61' are attached to the longitudinal bars 75 and 76 by means of upper lifting means fastenings 152 and 153 resting against the longitudinal bars. The lifting cylinders are directly disposed below the longitudinal bars 75 and 76 and, like them, they are symmetrically disposed to the central vertical axis 164 of the vehicle. The lifting pistons 61 and 61' are fastened to the wheel axis 13 by means of holding elements 59 and 151 between the wheels 14 and 14' directly adjacent to them. Lower lifting means fastenings 149 and 150 are formed on each of the holding elements. The lifting pistons movable in the lifting cylinders are mounted on the same. The ends of the lifting pistons 61 and 61' are guided through lifting piston guides 147 and 148 above the lower lifting means fastenings 149 and 150. A lateral view of the lifting means is represented in FIG. 12. The upper lifting means fastening 153 is visible below the longitudinal bar 76. The upper lifting means fastening is substantially formed by a profile disposed laterally on the longitudinal bar 76 in parallel to the longitudinal bar 76. A bore 154 is centrically formed in this profile for mounting the upper end of the lifting cylinder 61. Two supporting arms 62 and 63 pointing in the direction of the wheel axis are disposed on the ends of the profile on the longitudinal bar 76. A profile 148 is mounted near the free ends of the supporting arms between the same for fixing the lower end of the lifting cylinder 61. The lifting cylinder 61 itself extends centrally to the supporting arms 62 and 63 enclosing substantially a triangle with the longitudinal bar 76. In the representation according to FIG. 12 the lower bearing point of the lifting means is disposed directly below the profile 148. The holding element 59 resting against the free ends of the supporting arms 62 and 63 is represented on the free ends of the supporting arms 62 and 63. Its cross-section has substantially the shape of an isosceles triangle. The free ends of the supporting arms 62 and 63 rest against the ends of the base line of this triangle. The lower bearing point 150 of the lifting means is disposed centrally between these free ends in the centre of the base line. The two legs of the triangle point in the direction of the wheel axis 13 and encompass it partly. The lifting means with maximally extended lifting piston 60 is represented in FIG. 13. The same reference numerals designate the same elements in accordance with FIG. 12. They will only be dealt with partly. The longitudinal bar 76 is represented upwardly lifted by the distance g with respect to the wheel axis 13. The free ends 157 and 158 of the supporting arms have bearing journals 155 and 156. They are disposed in parallel to the lifting cylinder 61 or the lifting piston 60 and point towards the holding element 59. Corresponding bearing openings 159 and 160 are disposed in the holding element, which are in engagement with the bearing journals 155 and 156 in the representation according to FIG. 12.

A vehicle for beach cleaning has a vehicle frame with at least one wheel axis disposed on it. Garbage is picked up from the beach by a vertically adjustable garbage pickup and delivered to a conveyor adjoining the garbage pickup and conveying the garbage taken to a collecting receptacle disposed at the rear end of the vehicle frame. A supply rotor is allocated to the pickup area of the garbage pickup. In order to improve the supply, the pickup and the transport of refuse and the separation of refuse and sand and the disposal of the pollutants, a swivel frame supporting the garbage pickup and the supply rotor is lowerably mounted on the vehicle frame for vertical adjustment, the supply rotor being mounted on the swivel frame pivotably across a swivel range comprising different operating conditions by means of links and being in particular counter-clockwise rotatable about an axis of rotation mounted on the links.

This is a divisional of application Ser. No. 08/415,553, filed Apr. 3, 1995, now U.S. Pat. No. 5,861,187 which is a continuation-in-part of U.S. Ser. No. 07/739,965, filed Aug. 5, 1991, abandoned, which is a continuation-in-part of U.S. Ser. No. 07/575,542, filed Aug. 30, 1990, abandoned. TECHNICAL FIELD This invention relates to improved Brassica seeds, plants and oils having altered fatty acid profiles which provide advantageous nutritional or manufacturing properties. BACKGROUND OF THE INVENTION Diets high in saturated fats increase low density lipoproteins (LDL) which mediate the deposition of cholesterol on blood vessels. High plasma levels of serum cholesterol are closely correlated with atherosclerosis and coronary heart disease (Conner et al., Coronary Heart Disease: Prevention, Complications, and Treatment, pp. 43-46, 1985). By producing oilseed Brassica varieties with reduced levels of individual and total saturated fats in the seed oil, oil-based food products which contain less saturated fats can be produced. Such products will benefit public health by reducing the incidence of atherosclerosis and coronary heart disease. The dietary effects of monounsaturated fats have also been shown to have dramatic effects on health. Oleic acid, the only monounsaturated fat in most edible vegetable oils, lowers LDL as effectively as linoleic acid, but does not affect high density lipoproteins (HDL) levels (Mattson, F. H., J. Am. Diet. Assoc., 89:387-391, 1989; Mensink et al., New England J. Med., 321:436-441, 1989). Oleic acid is at least as effective in lowering plasma cholesterol as a diet low in fat an high in carbohydrates (Grundy, S. M., New England J. Med., 314:745-748, 1986; Mensink et al., New England J. Med., 321:436-441, 1989). In fact, a high oleic acid diet is preferable to low fat, high carbohydrate diets for diabetics (Garg et al., New England J. Med., 319:829-834, 1988). Diets high in monounsaturated fats are also correlated with reduced systolic blood pressure (Williams et al., J. Am. Med. Assoc., 257:3251-3256, 1987). Epidemiological studies have demonstrated that the "Mediterranean" Diet, which is high in fat and monosaturates, is not associated with coronary heart disease (Keys, A., Circulation 44(Suppl): 1, 1970). Many breeding studies have been conducted to improve the fatty acid profile of Brassica varieties. Pleines and Friedt, Fat Sci. Technol., 90(5), 167-171 (1988) describe plant lines with reduced C 18:3 levels (2.5-5.8%) combined with high oleic content (73-79%). Rakow and McGregor, J. Amer. Oil Chem. Soc., 50, 400-403 (October 1973) discuss problems associated with selecting mutants for linoleic and linolenic acids. In Can. J. Plant Sci, 68, 509-511 (April 1988) Stellar summer rape producing seed oil with 3% linolenic acid and 28% linoleic acid is disclosed. Roy and Tarr, Z. Pflanzenzuchtg, 95(3), 201-209 (1985) teaches transfer of genes through an interspecific cross from Brassica juncea into Brassica napus resulting in a reconstituted lien combining high linoleic with low linolenic acid content. Roy and Tarr, Plant Breeding, 98, 89-96 (1987) discuss prospects for development of B. napus L. having improved linolenic and linolenic acid content. European Patent application 323,751 published Jul. 12, 1989 discloses seeds and oils having greater than 79% oleic acid combined with less than 3.5% linolenic acid. Canvin, Can. J. Botany, 43, 63-69 (1965) discusses the effect of temperature on the fatty acid composition of oils from several seed crops including rapeseed. Mutations are typically induced with extremely high doses of radiation and/or chemical mutagens (Gaul, H. Radiation Botany (1964) 4:155-232). High dose levels which exceed LD50, and typically reach LD90, led to maximum achievable mutation rates. In mutation breeding of Brassica varieties high levels of chemical mutagens alone or combined with radiation have induced a limited number of fatty acid mutations (Rakow, G. Z. Pflanzenzuchtg (1973) 69:62-82). The low α-linolenic acid mutation derived from the Rakow mutation breeding program did not have direct commercial application because of low seed yield. The first commercial cultivar using the low α-linolenic acid mutation derived in 1973 was released in 1988 as the variety Stellar (Scarth, R. et al., Can. J. Plant Sci. (1988) 68:509-511). Stellar was 20% lower yielding than commercial cultivars at the time of its release. Canola-quality oilseed Brassica varieties with reduced levels of saturated fatty acids in the seed oil could be used to produce food products which promote cardiovascular health. Canola lines which are individually low in palmitic and stearic acid content or low in combination will reduce the levels of saturated fatty acids. Similarly, Brassica varieties with increased monounsaturate levels in the seed oil, and products derived from such oil, would improve lipid nutrition. Canola lines which are low in linoleic acid tend to have high oleic acid content, and can be used in the development of varieties having even higher oleic acid content. Increased palmitic acid content provides a functional improvement in food applications. Oils high in palmitic acid content are particularly useful in the formulation of margarines. Thus, there is a need for manufacturing purposes for oils high in palmitic acid content. Decreased alpha linolenic acid content provides a functional improvement in food applications. Oils which are low in linolenic acid have increased stability. The rate of oxidation of lipid fatty acids increases with higher levels of linolenic acid leading to off-flavors and off-odors in foods. There is a need in the food industry for oils low in alpha linolenic acid. SUMMARY OF THE INVENTION The present invention comprises canola seeds, plant lines producing seeds, and plants producing seed, said seeds having a maximum content of FDA saturates of about 5% and a maximum erucic acid content of about 2% based upon total extractable oil and belonging to a line in which said saturates content has been stabilized for both the generation to which the seed belongs and its parent generation. Progeny of said seeds and canola oil having a maximum erucic acid content of about 2%, based upon total extractable oil, are additional aspects of this invention. Preferred are seeds, plant lines producing seeds, and plants producing seeds, said seeds having an FDA saturates content of from about 4.2% to about 5.0% based upon total extractable oil. The present invention further comprises Brassica seeds, plant lines producing seeds, and plants producing seeds, said seeds having a minimum oleic acid content of about 71% based upon total extractable oil and belonging to a line in which said oleic acid content has been stabilized for both the generation to which the seed belongs and its parent generation. A further aspect of this invention is such high oleic acid seeds additionally having a maximum erucic acid content of about 2% based upon total extractable oil. Progeny of said seeds; and Brassica oil having 1) a minimum oleic acid content of about 71% or 2) a minimum oleic acid content of about 71% and a maximum erucic content of about 2% are also included in this invention. Preferred are seeds, plant lines producing seeds, and plants producing seeds, said seeds having an oleic acid content of from about 71.2% to about 78.3% based upon total extractable oil. The present invention further comprises canola seeds, plant lines producing seeds, and plants producing seeds, said seeds having a maximum linoleic acid content of about 14% and a maximum erucic acid content of about 2% based upon total extractable oil and belonging to a line in which said acid content is stabilized for both the generation to which the seed belongs and its parent generation. Progeny of said seeds and canola oil having a maximum linoleic acid content of about 14% and a maximum erucic acid content of about 2%, are additional aspects of this invention. Preferred are seeds, plant lines producing seeds, and plants producing seeds, said seeds having a linoleic acid content of from about 8.4% to about 9.4% based upon total extractable oil. The present invention further comprises Brassica seeds, plant lines producing seeds, and plant producing seeds, said seeds having a maximum palmitic acid content of about 3.5% and a maximum erucic acid content of about 2% based on total extractable oil and belonging to a line in which said acid content is stabilized for both the generation to which the seed belongs and its parent generation. Progeny of said seeds and canola having a maximum palmitic acid content of about 3.5% and a maximum erucic acid content of about 2%, are additional aspects of this invention. Preferred are seeds, plant lines producing seeds, and plants producing seeds, said seeds having a palmitic acid content of from about 2.7% to about 3.1% based upon total extractable oil. The present invention further comprises Brassica seeds, plant lines producing seeds, and plants producing seeds, said seeds having a minimum palmitic acid content of about 9.0% based upon total extractable oil and belonging to a line in which said acid content is stabilized for both the generation to which the seed belongs and its parent generation. A further aspect of this invention is such high palmitic acid seeds additionally having a maximum erucic acid content of about 2% based upon total extractable oil. Progeny of said seeds; and Brassica oil having 1) a minimum palmitic acid content of about 9.0%, or 2) a minimum palmitic acid content of about 9.0% and a maximum erucic acid content of about 2% are also included in this invention. Preferred are seeds, plant lines producing seeds, and plants producing seeds, said seeds having a palmitic acid content of from about 9.1% to about 11.7% based upon total extractable oil. The present invention further comprises Brassica seeds, plant lines producing seeds, and plants producing seeds, said seeds having a maximum stearic acid content of about 1.1% based upon total extractable oil and belonging to a line in which said acid content is stabilized for both the generation to which the seed belongs and its parent generation. Progeny of said seeds have a canola oil having a maximum stearic acid content of about 1.1% and maximum erucic acid content of about 2%. Preferred are seeds, plant lines producing seeds, and plants producing seeds having a stearic acid content of from about 0.8% to about 1.1% based on total extractable oil. The present invention further comprises Brassica seeds, plant lines producing seeds, and plants producing seeds, said seeds having a sum of linoleic acid content and linolenic acid content of a maximum of about 14% based upon total extractable oil and belonging to a line in which said acid content is stabilized for both the generation to which the seed belongs and its parent generation. Progeny of said seeds have a canola oil having a sum of linoleic acid content and linolenic acid content of a maximum of about 14% and a maximum erucic acid content of about 2%. Preferred are seeds, plant lines producing seeds, and plants producing seeds having a sum of linoleic acid content and linolenic acid content of from about 11.8% to about 12.5% based on total extractable oil. DETAILED DESCRIPTION OF THE INVENTION The U.S. Food and Drug Administration defines saturated fatty acids as the sum of lauric (C 12:0 ), myristic (C 14:0 ), palmitic (C 16:0 ) and stearic (C 18:0 ) acids. The term "FDA saturates" as used herein means this above-defined sum. Unless total saturate content is specified, the saturated fatty acid values expressed here include only "FDA saturates". All percent fatty acids herein are percent by weight of the oil of which the fatty acid is a component. As used herein, a "line" is a group of plants that display little or no genetic variation between individuals for at least one trait. Such lines may be created by several generations of self-pollination and selection, or vegetative propagation from a single parent using tissue or cell culture techniques. As used herein, the term "variety" refers to a line which is used for commercial production. As used here, "mutation" refers to a detectable and heritable genetic change not caused by segregation or genetic recombination. "Mutant" refers to an individual, or lineage of individuals, possessing a genetic mutation. The term "Mutagenesis" refers to the use of a mutagenic agent to induce random genetic mutations within a population of individuals. The treated population, or a subsequent generation of that population, is then screened for usable trait(s) that result from the mutations. A "population" is any group of individuals that share a common gene pool. As used herein "M 0 " is untreated seed. As used herein, "M 1 " is the seed (and resulting plants) exposed to a mutagenic agent, while "M 2 " is the progeny (seeds and plants) of self-pollinated M 1 plants, "M 3 " is the progeny of self-pollinated M 2 plants, and "M 4 " is the progeny of self-pollinated M 3 plants. "M 5 " is the progeny of self-pollinated M 4 plants. "M 6 ", "M 7 ", etc. are each the progeny of self-pollinated plants of the previous generation. The term "progeny" as used herein means the plants and seeds of all subsequent generations resulting from a particular designated generation. The term "selfed" as used herein means self-pollinated. "Stability" or "stable" as used herein means that with respect to a given fatty acid component, the component is maintained from generation to generation for at least two generations and preferably at least three generations at substantially the same level, e.g., preferably ±5%. The method of invention is capable of creating lines with improved fatty acid compositions stable up to ±5% from generation to generation. The above stability may be affected by temperature, location, stress and time of planting. Thus, comparison of fatty acid profiles should be made from seeds produced under similar growing conditions. Stability may be measured based on knowledge of prior generation. Intensive breeding has produced Brassica plants whose seed oil contains less than 2% erucic acid. The same varieties have also been bred so that the defatted meal contains less than 30 μmol glucosinolates/gram. "Canola" as used herein refers to plant variety seed or oil which contains less than 2% erucic acid (C 22:1 ), and meal with less than 30 μmol glucosinolates/gram. Seeds of Westar, a Canadian (Brassica napus) spring canola variety, were subject to chemical mutagenesis. Mutagenized seeds were planted in the greenhouse and the plants were self-pollinated. The progeny plants were individually analyzed for fatty acid composition, and regrown either in the greenhouse or in the field. After four successive generations of self-pollinations, followed by chemical analysis of the seed oil at each cycle, several lines were shown to carry stably inherited mutations in specific fatty acid components, including reduced palmitic acid (C 16:0 ), increased palmitic acid, reduced stearic acid (C 18:0 ), increased oleic acid (C 18:1 ), reduced linoleic acid (C 18:2 ) and reduced linolenic acid (C 18:3 ), in the seed oil. The general experimental scheme for developing lines with stable fatty acid mutations is shown in Scheme I hereinafter. ##STR1## Westar seeds (M 0 ) were mutagenized with ethylmethanesulfonate (EMS). Westar is a register Canadian spring variety with canola quality. The fatty acid composition of field-grown Westar, 3.9% C 16:0 , 1.9% C 18:0 , 67.5% C 18:1 , 17.6% C 18:2 , 7.4% C 18:3 , <2% C20:1+C 22:1 , has remained stable under commercial production, with <±10% deviation, since 1982. The disclosed method may be applied to all oilseed Brassica species, and to both Spring and Winter maturing types within each species. Physical mutagens, including but not limited to X-rays, UV rays, and other physical treatments which cause chromosome damage, and other chemical mutagens, including but not limited to ethidium bromide, nitrosoguanidine, diepoxybutane etc. may also be used to induce mutations. The mutagenesis treatment may also be applied to other stages of plant development, including but not limited to cell cultures, embryos, microspores and shoot apices. The M 1 seeds were planted in the greenhouse and M 1 plants were individually self-pollinated. M 2 seed was harvested from the greenhouse and planted in the field in a plant-to-row design. Each plot contained six rows, and five M 2 lines were planted in each plot. Every other plot contained a row of non-mutagenized Westar as a control. Based on gas chromatographic analysis of M 2 seed, those lines which had altered fatty acid composition were self-pollinated and individually harvested. M 3 seeds were evaluated for mutations on the basis of a Z-distribution. An extremely stringent 1 in 10,000 rejection rate was employed to establish statistical thresholds to distinguish mutation events from existing variation. Mean and standard deviation values were determined from the non-mutagenized Westar control population in the field. The upper and lower statistical thresholds for each fatty acid were determined from the mean value of the population±the standard deviation, multiplied by the Z-distribution. Based on a population size of 10,000, the confidence interval is 99.99%. Seeds (M 3 ) from those M 2 lines which exceeded either the upper or lower statistical thresholds were replanted in the greenhouse and self-pollinated. This planting also include Westar controls. The M 4 seed was re-analyzed using new statistical thresholds established with a new control population. Those M 4 lines which exceeded the new statistical thresholds for selected fatty acid compositions were advanced to the nursery. Following self-pollination, M 5 seed from the field were re-analyzed once again for fatty acid composition. Those lines which remained stable for the selected fatty acids were considered stable mutations. "Stable mutations" as used herein are defined as M 5 or more advanced lines which maintain a selected altered fatty acid profile for a minimum of three generations, including a minimum of two generations under field conditions, and exceeding established statistical thresholds for a minimum of two generations, as determined by gas chromatographic analysis of a minimum of 10 randomly selected seeds bulked together. Alternatively, stability may be measured in the same way by comparing to subsequent generations. In subsequent generations, stability is defined as having similar fatty acid profiles in the seed as that of the prior or subsequent generation when grown under substantially similar conditions. The amount of variability for fatty acid content in a seed population is quite significant when single seeds are analyzed. Randomly selected single seeds and a ten seed bulk sample of a commercial variety were compared. Significant variation among the single seeds was detected (Table A). The half-seed technique (Downey, R. K. and B. L. Harvey, Can. J. Plant Sci., 43:271 [1963]) in which one cotyledon of the germinating seed is analyzed for fatty acid composition and the remaining embryo grown into a plant has been very useful to plant breeding work to select individuals in a population for further generation analysis. The large variation seen in the single seed analysis (Table A) is reflected in the half-seed technique. TABLE A__________________________________________________________________________Single Seed Analysis for Fatty Acid Composition.sup.1FATTY ACIDSSAMPLE16:0 16:1 18:0 18:1 18:2 18:3 20:0 20:1 22:0 22:1__________________________________________________________________________Bulk 3.2 0.4 1.8 20.7 13.7 9.8 0.8 11.2 0.4 32.2 1 2.8 0.2 1.1 14.6 14.6 11.1 0.8 9.8 0.7 38.2 2 3.3 0.2 1.3 13.1 14.4 11.7 0.9 10.5 0.7 37.0 3 3.0 -- 1.2 12.7 15.3 10.6 0.8 7.3 0.7 43.2 4 2.8 0.2 1.1 16.7 13.2 9.1 0.8 11.2 0.4 38.9 5 3.0 -- 1.8 15.2 13.3 8.4 1.3 8.7 0.9 42.3 6 3.1 -- 1.3 14.4 14.6 10.3 1.0 10.9 0.8 39.3 7 2.6 -- 1.2 15.7 13.8 9.9 0.9 12.2 0.5 37.0 8 3.1 -- 1.1 16.2 13.4 10.6 0.6 9.2 0.8 41.4 9 2.7 0.1 1.0 13.5 11.2 11.3 0.8 6.2 0.7 46.910 3.4 0.2 1.4 13.9 17.5 10.8 1.1 10.0 0.9 36.211 2.8 0.2 1.2 12.7 12.9 10.3 1.0 7.9 0.9 43.312 2.3 0.1 1.6 20.7 14.8 6.5 1.1 12.5 0.8 34.513 2.6 0.2 1.3 21.0 11.4 7.6 1.0 11.6 0.6 36.714 2.6 0.1 1.2 14.7 13.2 9.4 0.9 10.1 0.8 40.815 2.9 0.2 1.4 16.6 15.1 11.2 0.7 9.1 0.3 36.116 3.0 0.2 1.1 12.4 13.7 10.4 0.9 8.7 0.8 42.717 2.9 0.1 1.1 21.1 12.3 7.1 0.8 12.4 0.5 36.818 3.1 0.1 1.2 13.7 13.1 10.4 1.0 8.8 0.7 41.619 2.7 0.1 1.0 11.1 13.4 11.7 0.8 7.9 0.8 43.520 2.3 0.2 0.2 18.2 13.9 8.2 0.9 10.3 0.8 38.2Average2.8 0.2 1.2 15.4 13.8 9.8 0.9 9.8 0.7 39.7Minimum2.3 0.1 0.2 11.1 11.2 6.5 0.6 6.2 0.3 34.5Maximum3.4 0.2 1.8 21.1 17.5 11.7 1.3 12.5 0.9 46.9Range1.1 0.1 1.6 9.9 6.3 5.3 0.7 6.4 0.6 12.4__________________________________________________________________________ .sup.1 Values expressed as percent of total oil Plant breeders using the half-seed technique have found it unreliable in selecting stable genetically controlled fatty acid mutations (Stafanson, B. R., In; High and Low Erucic Acid Rapeseed Oils, Ed. N. T. Kenthies, Academic Press, Inc., Canada (1983) pp. 145-159). Although valuable in selecting individuals from a population, the selected traits are not always transmitted to subsequent generations (Rakow, G., and McGregor, D. I., J. Amer. Oil Chem. Soc. (1973) 50:400-403. To determine the genetic stability of the selected plants several self-pollinated generations are required (Robelen, G. In; Biotechnology for the Oils and Fats Industry, Ed. C. Ratledge, P. Dawson and J. Rattray, American Oil Chemists Society (1984) pp. 97-105) with chemical analysis of a bulk seed sample. Mutation breeding has traditionally produced plants carrying, in addition to the trait of interest, multiple, deleterious traits, e.g., reduced plant vigor and reduced fertility. Such traits may indirectly affect fatty acid composition, producing an unstable mutation; and/or reduce yield, thereby reducing the commercial utility of the invention. To eliminate the occurrence of deleterious mutations and reduce the load of mutations carried by the plant a low mutagen dose was used in the seed treatments to create an LD30 population. This allowed for the rapid selection of single gene mutations for fatty acid traits in agronomic backgrounds which produce acceptable yields. Other than changes in the fatty acid composition of the seed oil, the mutant lines described here have normal plant phenotype when grown under field conditions, and are commercially useful. "Commercial utility" is defined as having a yield, as measured by total pounds of seed or oil produced per acre, within 15% of the average yield of the starting (M 0 ) canola variety grown in the same region. To be commercially useful, plant vigor and high fertility are such that the crop can be produced in this yield by farmers using conventional farming equipment, and the oil with altered fatty acid composition can be extracted using conventional crushing and extraction equipment. The seeds of several different fatty acid lines have been deposited with the American Type Culture Collection and have the following accession numbers. ______________________________________Line Accession No.______________________________________A129.5 40811A133.1 40812A144.1 40813A200.7 40816M3032.1 75021M3094.4 75023M3052.6 75024M3007.4 75022M3062.8 75025M3028.10 75026______________________________________ While the invention is susceptible to various modifications and alternative forms, certain specific embodiments thereof are described in the general methods and examples set forth below. For example the invention may be applied to all Brassica species, including B. rapa, B. juncea, and B. hirta, to produce substantially similar results. It should be understood, however, that these examples are not intended to limit the invention to the particular forms disclosed but, instead the invention is to cover all modifications, equivalents and alternatives falling within the scope of the invention. This includes the use of somaclonal variation; physical or chemical mutagenesis of plant parts; anther, microspore or ovary culture followed by chromosome doubling; or self- or cross-pollination to transmit the fatty acid trait, along or in combination with other traits, to develop new Brassica lines. EXAMPLE 1 Selection of Low FDA Saturates Prior to mutagenesis, 30,000 seeds of B. napus cv. Westar seeds were preimbibed in 300-seed lots for two hours on wet filter paper to soften the seed coat. The preimbibed seeds were placed in 80 mM ethylmethanesulfonate (EMS) for four hours. Following mutagenesis, the seeds were rinsed three times in distilled water. The seeds were sown in 48-well flats containing Pro-Mix. Sixty-eight percent of the mutagenized seed germinated. The plants were maintained at 25° C./15° C., 14/10 hr day/night conditions in the greenhouse. At flowing, each plant was individually self-pollinated. M 2 seed from individual plants were individually catalogued and stored, approximately 15,000 M 2 lines was planted in a summer nursery in Carman, Manitoba. The seed from each selfed plant were planted in 3-meter rows with 6-inch row spacing. Westar was planted as the check variety. Selected lines in the field were selfed by bagging the main raceme of each plant. At maturity, the selfed plants were individually harvested and seeds were catalogued and stored to ensure that the source of the seed was known. Self-pollinated M 3 seed and Westar controls were analyzed in 10-seed bulk samples for fatty acid composition via gas chromatography. Statistical thresholds for each fatty acid component were established using a Z-distribution with a stringency level of 1 in 10,000. The selected M 3 seeds were planted in the greenhouse along with Westar controls. The seed was sown in 4-inch pots containing Pro-Mix soil and the plants were maintained at 25° C./15° C., 14/10 hr day/night cycle in the greenhouse. At flowering, the terminal raceme was self-pollinated by bagging. At maturity, selfed M 4 seed was individually harvested from each plant, labelled, and stored to ensure that the source of the seed was known. The M 4 seed was analyzed in 10-seed bulk samples. Statistical thresholds for each fatty acid component were established from 259 control samples using a Z-distribution of 1 in 800. Selected M 4 lines were planted in a field trial in Carman, Manitoba in 3-meter rows with 6-inch spacing. Ten M 4 plants in each row were bagged for self-pollination. At maturity, the selfed plants were individually harvested and the open pollinated plants in the row were bulk harvested. The M 5 seed from single plant selections was analyzed in 10-seed bulk samples and the bulk row harvest in 50-seed bulk samples. Selected M 5 lines were planted in the greenhouse along with Westar controls. The seed was grown as previously described. At flowering the terminal raceme was self-pollinated by bagging. At maturity, selfed M 6 seed was individually harvested from each plant and analyzed in 10-seed bulk samples for fatty acid composition. Selected M 6 lines were entered into field trials in Eastern Idaho. The four trial locations were selected for the wide variability in growing conditions. The locations include Burley, Tetonia, Lamont and Shelley (Table I). The lines were planted in four 3-meter rows with an 8-inch spacing, each plot was replicated four times. The planting design was determined using a Randomized Complete Block Design. The commercial cultivar Westar was used as a check cultivar. At maturity the plots were harvested to determine yield. Yield of the entries in the trial was determined by taking the statistical average of the four replications. The Least Significant Difference Test was used to rank the entries in the randomized complete block design. TABLE I______________________________________Trial Locations for Selected Fatty Acid MutantsLOCATION SITE CHARACTERISTICS______________________________________BURLEY Irrigated. Long season. High temperatures during flowering.TETONIA Dryland. Short season. Cool temperatures.LAMONT Dryland. Short season. Cool temperatures.SHELLEY Irrigated. Medium season. High temperatures during flowering.______________________________________ To determine the fatty acid profile of entries, plants in each plot were bagged for self-pollination. The M 7 seed from single plants was analyzed for fatty acids in ten-seed bulk samples. To determine the genetic relationships of the selected fatty acid mutants crosses were made. Flowers of M 6 or later generation mutations were used in crossing. F 1 seed was harvested and analyzed for fatty acid composition to determine the mode of gene action. The F 1 progeny were planted in the greenhouse. The resulting plants were self-pollinated, the F 2 seed harvested and analyzed for fatty acid composition for allelism studies. The F 2 seed and parent line seed was planted in the greenhouse, individual plants were self-pollinated. The F 3 seed of individual plants was tested for fatty acid composition using 10-seed bulk samples as described previously. In the analysis of some genetic relationships dihaploid populations were made from the microspores of the F 1 hybrids. Self-pollinated seed from diphaloid plants were analyzed for fatty acid analysis using methods described previously. For chemical analysis, 10-seed bulk samples were hand ground with a glass rod in a 15-mL polypropylene tube and extracted in 1.2 mL 0.25 N KOH in 1:1 ether/methanol. The sample was vortexed for 30 sec and heated for 60 sec in a 60° C. water bath. Four mL of saturated NaCl and 2.4 mL of iso-octane were added, and the mixture was vortexed again. After phase separation, 600 μL of the upper organic phase were pipetted into individual vials and stored under nitrogen at -5° C. One μL samples were injected into a Supelco SP-2330 fused silica capillary column (0.25 mm ID, 30 M length, 0.20 μm df). The gas chromatograph was set at 180° C. for 5.5 minutes, then programmed for a 2° C./minute increase to 212° C., and held at this temperature for 1.5 minutes. Total run time was 23 minutes. Chromatography settings were: Column head pressure--15 psi, Column flow (He)--0.7 mL/min, Auxiliary and Column flow--33 mL/min, Hydrogen flow--33 mL/min, Air flow--400 mL/min, Injector temperature--250° C., Detector temperature--300° C., Split vent--1/15. Table II describes the upper and lower statistical thresholds for each fatty acid of interest. TABLE II______________________________________Statistical Thresholds for Specific Fatty AcidsDerived From Control Westar Plantings Percent Fatty AcidsGenotype C.sub.16:0 C.sub.18:0 C.sub.18:1 C.sub.18:2 Sats*______________________________________M.sub.3 Generation (1 in 10,000 rejection rate)Lower 3.3 1.4 -- 13.2 5.3 6.0Upper 4.3 2.5 71.0 21.6 9.9 8.3M.sub.4 Generation (1 in 800 rejection rate)Lower 3.6 0.8 -- 12.2 3.2 5.3Upper 6.3 3.1 76.0 32.4 9.9 11.2M.sub.5 Generation (1 in 755 rejection rate)Lower 2.7 0.9 -- 9.6 2.6 4.5Upper 5.7 2.7 80.3 26.7 9.6 10.0______________________________________ *Sats = Total Saturate Content At the M 3 generation, twelve lines exceeded the lower statistical threshold for palmitic acid (≦3.3%). Line W13097.4 had 3.1% palmitic acid and an FDA saturate content of 4.5%. After a cycle in the greenhouse, M 4 seed from line W13097.4 (designated line A144) was analyzed. Line W13097.4.1 (A144.1) had 3.1% C 16:0 , exceeding the lower statistical threshold of 3.6%. The FDA saturate content for A144.1 was 4.5%. The fatty acid compositions for the M 3 , M 4 and M 5 generations of this family are summarized in Table III. TABLE III______________________________________Fatty Acid Composition of a Low Palmitic Acid/Low FDASaturate Canola Line Produced by Seed MutagenesisPercent Fatty AcidsGenotype.sup.a C.sub.16:0 C.sub.18:0 C.sub.18:1 C.sub.18:2 C.sub.18:3 Sats.sup.b Tot Sat.sup.c______________________________________Westar 3.9 1.9 67.5 17.6 7.4 5.9 7.0W13097.4 3.1 1.4 63.9 18.6 9.5 4.5 5.6(M.sub.3)W13097.4 3.1 1.4 66.2 19.9 6.0 4.5 5.5(M.sub.4)A144.1.9 2.9 1.4 64.3 20.7 7.3 4.4 5.3(M.sub.5)______________________________________ .sup.a Letter and numbers up to second decimal point indicate the plant line. Number after second decimal point indicates an individual plant. .sup.b Sat = FDA Saturates .sup.c Tot Sat = Total Saturate Content The M 5 seed of two self-pollinated A144.1 (ATCC 40813) plants averaged 3.1% palmitic acid and 4.7% FDA saturates. One selfed plant (A144.1.9) contained 2.9% palmitic acid and FDA saturates of 4.4%. Bulk seed analysis from open-pollinated (A144.1) plants at the M 5 generation averaged 3.1% palmitic acid and 4.7% FDA saturates. The fatty acid composition of the bulked and individual A144.1 lines are summarized in Table IV. TABLE IV______________________________________Fatty Acid Composition of A144Low Palmitic Acid/Low FDA Saturate LinePercent Fatty AcidsGenotype.sup.a C.sub.16:0 C.sub.18:0 C.sub.18:1 C.sub.18:2 C.sub.18:3 Sats.sup.b Tot Sat.sup.c______________________________________Individually Self-Pollinated PlantsA144.1.1 3.2 1.6 64.4 20.5 7.0 4.8 5.9A144.1.2 3.0 1.5 67.4 18.6 6.3 4.5 5.7A144.1.3 3.6 1.8 61.4 22.4 7.5 5.2 6.6A144.1.4 3.2 1.5 64.6 20.9 6.7 4.7 5.8A144.1.5 3.3 1.7 60.0 23.9 7.9 5.0 6.1A144.1.6 3.1 1.4 67.3 17.8 6.5 4.6 5.2A144.1.7 3.1 1.6 67.7 17.4 6.5 4.8 5.4A144.1.8 3.1 1.8 66.9 18.7 6.1 4.9 5.4A144.1.9 2.9 1.4 64.3 20.7 7.3 4.4 5.3A144.1.10 3.1 1.5 62.5 20.4 7.7 4.6 5.6Average of Individually Self-Pollinated PlantsA144.1.1-10 3.1 1.6 64.8 20.1 6.9 4.7 5.7Bulk Analysis of Open-Pollinated PlantsA144.1B 3.1 1.6 64.8 19.4 7.8 4.7 5.7______________________________________ .sup.a Letter and numbers up to second decimal point indicate the plant line. Number after second decimal point indicates an individual plant .sup.b Sat = FDA Saturates .sup.c Tot Sat = Total Saturate Content These reduced levels have remained stable to the M 7 generations in both greenhouse and field conditions. These reduced levels have remained stable to the M 7 generation in multiple location field trails. Over all locations, the self-pollinated plants (A144) averaged 2.9% palmitic acid and FDA saturates of 4.6%. The fatty acid composition of the A144 lines for each Idaho location are summarized in Table V. In the multiple location replicated trial the yield of A144 was not significantly different in yield from the parent cultivar Westar. By means of seed mutagenesis, the level of saturated fatty acids of canola (B. napus) was reduced from 5.9% to 4.6%. The palmitic acid content was reduced from 3.9% to 2.9%. TABLE V______________________________________Fatty Acid Composition of a MutantLow Palmitic Acid/Low FDA SaturateCanola Line at Different Field Locations in IdahoTrial Percent Fatty AcidsLocation C.sub.16:0 C.sub.18:0 C.sub.18:1 C.sub.18:2 C.sub.18:3 Sats Tot Sat______________________________________Burley 2.9 1.3 62.3 20.6 10.3 4.2 5.0Tetonia 2.9 1.7 59.7 21.0 11.2 4.6 5.7Lamont 3.1 1.8 63.2 19.5 9.0 4.9 5.9Shelley 2.8 1.9 64.5 18.8 8.8 4.7 5.9______________________________________ To determine the genetic relationship of the palmitic acid mutation in A144 (C 16:0 --3.0%, C 18:0 --1.5%, C 18:1 --67.4%, C 18:2 --18.6%, C 18:3 --6.3%) to other fatty acid mutations it was crossed to A129 a mutant high oleic acid (C 16:0 --3.8%, C 18:0 --2.3%, C 18:1 --75.6), C 18:2 --9.5%, C 18:3 --4.9%). Over 570 dihaploid progeny produced from the F 1 hybrid were harvested and analyzed for fatty acid composition. The results of the progeny analysis are summarized in Table VB. Independent segregation of the palmitic traits was observed which demonstrates that the genetic control of palmitic acid in A144 is different from the high oleic acid mutation in A129. TABLE VB______________________________________Genetic Studies of Dihaploid Progeny of A144 X A129 C.sub.16:0 FrequencyGenotype Content (%) Observed Expected______________________________________p-p-p2-p2- 3.0% 162 143p+p+p2-p2- 3.4% 236 286p+p+p2+p2+ 3.8% 175 143______________________________________ EXAMPLE 2 An additional low FDA saturate line, designated A149.3 (ATCC 40814), was also produced by the method of Example 1. A 50-seed bulk analysis of this line showed the following fatty acid composition: C 16:0 --3.6%, C 18:0 --1.4%, C 18:1 --65.5%, C 18:2 --18.3%, C 18:3 --8.2%, FDA Sats--5.0%, Total Sats--5.9%. This line has also stably maintained its mutant fatty acid composition to the M 5 generation. In a multiple location replicated trial the yield of A149 was not significantly different in yield from the parent cultivar Westar. EXAMPLE 3 An additional low palmitic acid and low FDA saturate line, designated M3094.4 (ATCC 75023), was also produced by the method of Example 1. A 10-seed bulk analysis of this line showed the following fatty acid composition: C 16:0 --2.7%, C 18:0 --1.6%, C 18:1 --66.6%, C 18:2 --20.0%, C 18:3 --6.1%, C 20:1 --1.4%, C 22:1 --0.0%, FDA Saturate--4.3%, Total Saturates--5.2%. This line has stably maintained its mutant fatty acid composition to the M 5 generation. In a single replicated trial the yield of M3094 was not significantly different in yield from the parent cultivar. M3094.4 was crossed to A144, a low palmitic acid mutation (Example 1) for allelism studies. Fatty acid composition of the F 2 seed showed the two lines to be allelic. The mutational events in A144 and M3094, although different in origin, are in the same gene. EXAMPLE 4 In the studies of Example 1, at the M 3 generation, 470 lines exceed the upper statistical threshold for palmitic acid (≧4.3%). One M 3 line, W14538.6, contained 9.2% palmitic acid. Selfed progenies of this line, since designated M3007.4 (ATCC 75022), continued to exceed to the upper statistical threshold for high palmitic acid at both the M 4 and M 5 generations with palmitic acid levels of 11.7% and 9.1%, respectively. The fatty acid composition of this high palmitic acid mutant, which was stable to the M 7 generation under both field and greenhouse conditions, is summarized in Table VI. TABLE VI______________________________________Fatty Acid Composition of a HighPalmitic Acid Canola Line Produced by Seed Mutagenesis Percent Fatty AcidsGenotype C.sub.16:0 C.sub.18:0 C.sub.18:1 C.sub.18:2 C.sub.18:3 Sats*______________________________________Westar 3.9 1.9 67.5 17.6 7.4 7.0W14538.6 8.6 1.6 56.4 20.3 9.5 10.2(M.sub.3)M3007.2 11.7 2.1 57.2 18.2 5.1 13.9(M.sub.4)M3007.4 9.1 1.4 63.3 13.7 5.5 12.7(M.sub.5)______________________________________ *Sats = Total Saturate Content To determine the genetic relationship of the high palmitic mutation in M3007.4 to the low palmitic mutation in A144 (Example 1) crosses were made. The F 2 progeny were analyzed for fatty acid composition. The data presented in Table VIB shows the high palmitic group (C 16:0 ≦7.0%) makes up one-quarter of the total population analyzed. The high palmitic acid mutation was controlled by one single gene mutation. TABLE VIB______________________________________Genetic Studies of M3007 X A144 C.sub.16:0 FrequencyGenotype Content (%) Observed Expected______________________________________p-p-/p-hp- <7.0 151 142hp-hp- >7.0 39 47______________________________________ An additional M 3 line, W4773.7, contained 4.5% palmitic acid. Selfed progenies of this line, since designated A200.7 (ATCC 40816), continued to exceed the upper statistical threshold for high palmitic acid in both the M 4 and M 5 generations with palmitic acid levels of 6.3% and 6.0%, respectively. The fatty acid composition of this high palmitic acid mutant, which was stable to the M 7 generation under both field and greenhouse conditions, is summarized in Table VII. TABLE VII______________________________________Fatty Acid Composition of a HighPalmitic Acid Canola Line Produced by Seed Mutagenesis Percent Fatty AcidsGenotype C.sub.16:0 C.sub.18:0 C.sub.18:1 C.sub.18:2 C.sub.18:3 Sats*______________________________________Westar 3.9 1.9 67.5 17.6 7.4 7.0W4773.7 4.5 2.9 63.5 19.9 7.1 9.3(M.sub.3)W4773.7.7 6.3 2.6 59.3 20.5 5.6 10.8(M.sub.4)A200.7.7 6.0 1.9 60.2 20.4 7.3 9.4(M.sub.5)______________________________________ *Sats = Total Saturate Content EXAMPLE 5 Selection of Low Stearic Acid Canola Lines In the studies of Example 1, at the M 3 generation, 42 lines exceeded the lower statistical threshold for stearic acid (<1.4%). Line W14859.6 had 1.3% stearic acid. At the M 5 generation, its selfed progeny (M3052.1) continued to fall within the lower statistical threshold for C 18:0 with 0.8% stearic acid. The fatty acid composition of this low stearic acid mutant, which was stable under both field and greenhouse conditions is summarized in Table VIII. In a single location replicated yield trial M3052.1 was not significantly different in yield from the parent cultivar Westar. TABLE VIII______________________________________Fatty Acid Composition of a LowStearic Acid Canola Line Produced by Seed Mutagenesis Percent Fatty AcidsGenotype C.sub.16:0 C.sub.18:0 C.sub.18:1 C.sub.18:2 C.sub.18:3 Sats______________________________________Westar 3.9 1.9 67.5 17.6 7.4 5.9W14859.6 5.3 1.3 56.1 23.7 9.6 7.5(M.sub.3)M3052.1 4.9 0.9 58.9 22.7 9.3 5.8(M.sub.4)M3052.6 4.4 0.8 62.1 21.2 7.9 5.2(M.sub.5)______________________________________ To determine the genetic relationship of the low stearic acid mutation of M3052.1 to other fatty acid mutations it was crossed to the low palmitic acid mutation A144 (Example 1). Seed from over 300 dihaploid progeny were harvested and analyzed for fatty acid composition. The results are summarized in Table VIIIB. Independent segregation of the palmitic acid and stearic acid traits was observed. The low stearic acid mutation was genetically different from the low palmitic acid mutations found in A144 and M3094. TABLE VIIIB______________________________________Genetic Studies of M3052 X A144 C.sub.16:0 + C.sub.18:0 FrequencyGenotype Content (%) Observed Expected______________________________________p-p-s-s- <4.9% 87 77p-p-s-s-/p+p+s-s- 4.0% < X < 5.6% 152 154p+p+s+s+ >5.6% 70 77______________________________________ An additional M 5 line, M3051.10, contained 0.9% and 1.1% stearic acid in the greenhouse and field respectively. A ten-seed analysis of thie line showed the following fatty acid composition: C 16:0 --3.9%, C 18:0 --1.1%, C 18:1 --16.7%, C 18:2 --23.0%, C 18:3 --7.6%, FDA saturates--5.0%, Total Saturates--5.8%. In a single location replicated yield trial M3051.10 was not significantly different in yield from the parent cultivar Westar. M3051.10 was crossed to M3052.1 for allelism studies. Fatty acid composition of the F 2 seed showed the two lines to be allelic. The mutational events in M3051.10 and M3052.1 although different in origin were in the same gene. An additional M5 line, M3054.7, contained 1.0% and 1.3% stearic acid in the greenhouse and field respectively. A ten-seed analysis of this line showed the following fatty acid composition: C 16:0 --4.0%, C 18:0 --1.0%, C 18:1 --66.5%, C 18:2 --18.4%, C 18:3 --7.2%, FDA saturates--5.0%, Total Saturates--6.1%. In a single location replicated yield trial M3054.7 was not significantly different in yield from the parent cultivar Westar. M3054.7 was crossed to M3052.1 for allelism studies. Fatty acid composition of the F 2 seed showed the two lines to be allelic. The mutational events in M3054.7, M3051.10 and M3052.1 although different in origin were in the same gene. EXAMPLE 6 High Oleic Acid Canola Lines In the studies of Example 1, at the M 3 generation, 31 lines exceeded the upper statistical threshold for oleic acid (≧71.0%). Line W7608.3 had 71.2% oleic acid. At the M 4 generation, its selfed progeny (W7608.3.5, since designated A129.5) continued to exceed the upper statistical threshold for C 18:1 with 78.8% oleic acid. M 5 seed of five self-pollinated plants of line A129.5 (ATCC 40811) averaged 75.0% oleic acid. A single plant selection, A129.5.3 had 75.6% oleic acid. The fatty acid composition of this high oleic acid mutant, which was stable under both field and greenhouse conditions to the M 7 generation, is summarized in Table IX. This line also stably maintained its mutant fatty acid composition to the M 7 generation in field trials in multiple locations. Over all locations the self-pollinated plants (A129) averaged 78.3% oleic acid. The fatty acid composition of A129 for each Idaho trial location are summarized in Table X. In multiple location replicated yield trials, A129 was not significantly different in yield from the parent cultivar Westar. The canola oil of A129, after commercial processing, was found to have superior oxidative stability compared to Westar when measured by the Accelerated Oxygen Method (AOM), American Oil Chemists' Society Official Method Cd 12-57 for fat stability; Active Oxygen Method (revised 1989). The AOM of Westar was 18 AOM hours and for A129 was 30 AOM hours. TABLE IX______________________________________Fatty Acid Composition of a HighOleic Acid Canola Line Produced by Seed Mutagenesis Percent Fatty AcidGenotype C.sub.16:0 C.sub.18:0 C.sub.18:1 C.sub.18:2 C.sub.18:3 Sats______________________________________Westar 3.9 1.9 67.5 17.6 7.4 7.0W7608.3 3.9 2.4 71.2 12.7 6.1 7.6(M.sub.3)W7608.3.5 3.9 2.0 78.8 7.7 3.9 7.3(M.sub.4)A129.5.3 3.8 2.3 75.6 9.5 4.9 7.6(M.sub.5)______________________________________ Sats = Total Saturate Content TABLE X______________________________________Fatty Acid Composition of a Mutant HighOleic Acid Line at Different Field Locations in Idaho Percent Fatty AcidsLocation C.sub.16:0 C.sub.18:0 C.sub.18:1 C.sub.18:2 C.sub.18:3 Sats______________________________________Burley 3.3 2.1 77.5 8.1 6.0 6.5Tetonia 3.5 3.4 77.8 6.5 4.7 8.5Lamont 3.4 1.9 77.8 7.4 6.5 6.3Shelley 3.3 2.6 80.0 5.7 4.5 7.7______________________________________ Sats = Total Saturate Content The genetic relationship of the high oleic acid mutation A129 to other oleic desaturases was demonstrated in crosses made to commercial canola cultivars and a low linolenic acid mutation. A129 was crossed to the commercial cultivar Global (C 16:0 --4.5%, C 18:0 --1.5%, C 18:1 --62.9%, C 18:2 --20.0%, C 18:3 --7.3%). Approximately 200 F 2 individuals were analyzed for fatty acid composition. The results are summarized in Table XB. The segregation fit 1:2:1 ratio suggesting a single co-dominant gene controlled the inheritance of the high oleic acid phenotype. TABLE XB______________________________________Genetic Studies of A129 X Global C.sub.18:1 FrequencyGenotype Content (%) Observed Expected______________________________________od-od- 77.3 43 47od-od+ 71.7 106 94od+od+ 66.1 49 47______________________________________ A cross between A129 and IMC01, a low linolenic acid variety (C 16:0 --4.1%, C 18:0 --1.9%, C 18:1 --66.4%, C 18:2 --18.1%, C 18:3 --5.7%), was made to determine the inheritance of the oleic acid desaturase and linoleic acid desaturase. In the F 1 hybrids both the oleic acid and linoleic acid desaturase genes approached the mid-parent values indicating the co-dominant gene actions. Fatty acid analysis of the F 2 individuals confirmed a 1:2:1:2:4:2:1:2:1 segregation of two independent, co-dominant genes (Table XC). TABLE XC______________________________________Genetic Studies of A129 X IMC 01 FrequencyGenotype Ratio Observed Expected______________________________________od-od-ld-ld- 1 11 12od-od-ld-ld+ 2 30 24od-od-ld+ld+ 1 10 12od-od+ld-ld- 2 25 24od-od+ld-ld+ 4 54 47od-od+ld+ld+ 2 18 24od+od+ld-ld- 1 7 12od+od+ld-ld+ 2 25 24od+od+ld+ld+ 1 8 12______________________________________ An additional high oleic acid line, designated A128.3, was also produced by the disclosed method. A 50-seed bulk analysis of this line showed the following fatty acid composition: C 16:0 --3.5%, C 18:0 --1.8%, C 18:1 --77.3%, C 18:2 --9.0%, C 18:3 --5.6%, FDA Sats--5.3%, Total Sats--6.4%. This line also stably maintained its mutant fatty acid composition to the M 7 generation. In multiple locations replicated yield trials, A128 was not significantly different in yield from the parent cultivar Westar. A129 was crossed to A128.3 for allelism studies. Fatty acid composition of the F 2 seed showed the two lines to be allelic. The mutational events in A129 and A128.3 although different in origin were in the same gene. An additional high oleic acid line, designated M3028.-10 (ATCC 75026), was also produced by the disclosed method in Example 1. A 10-seed bulk analysis of this line showed the following fatty acid composition: C 16:0 --3.5%, C 18:0 --1.8%, C 18:1 --77.3%, C 18:2 --9.0%, C 18:3 --5.6%, FDA Saturates--5.3%, Total Saturates--6.4%. In a single location replicated yield trial M3028.10 was not significantly different in yield from the parent cultivar Westar. EXAMPLE 7 Low Linoleic Acid Canola In the studies of Example 1, at the M 3 generation, 80 lines exceeded the lower statistical threshold for linoleic acid (≦13.2%). Line W12638.8 had 9.4% linoleic acid. At the M 4 and M 5 generations, its selfed progenies [W12638.8, since designated A133.1 (ATCC 40812)] continued to exceed the statistical threshold for low C 18:2 with linoleic acid levels of 10.2% and 8.4%, respectively. The fatty acid composition of this low linoleic acid mutant, which was stable to the M 7 generation under both field and greenhouse conditions, is summarized in Table XI. In multiple location replicated yield trials, A133 was not significantly different in yield from the parent cultivar Westar. An additional low linoleic acid line, designated M3062.8 (ATCC 75025), was also produced by the disclosed method. A 10-seed bulk analysis of this line showed the following fatty acid composition: C 16:0 --3.8%, C 18:0 --2.3%, C 18:1 --77.1%, C 18:2 --8.9%, C 18:3 --4.3%, FDA Sats--6.1%. This line has also stably maintained its mutant fatty acid composition in the field and greenhouse. TABLE XI______________________________________Fatty Acid Composition of a LowLinoleic Acid Canola Line Produced by Seed Mutagenesis Percent Fatty AcidsGenotype.sup.a C.sub.16:0 C.sub.18:0 C.sub.18:1 C.sub.18:2 C.sub.18:3 Sats.sup.b______________________________________Westar 3.9 1.9 67.5 17.6 7.4 7.0W12638.8 3.9 2.3 75.0 9.4 6.1 7.5(M.sub.3)W12638.8.1 4.1 1.7 74.6 10.2 5.9 7.1(M.sub.4)A133.1.8 3.8 2.0 77.7 8.4 5.0 7.0(M.sub.5)______________________________________ .sup.a Letter and numbers up to second decimal point indicate the plant line. Number after second decimal point indicates an individual plant. .sup.b Sats = Total Saturate Content EXAMPLE 8 Low Linolenic and Linoleic Acid Canola In the studies of Example 1, at the M 3 generation, 57 lines exceeded the lower statistical threshold for linolenic acid (≦5.3%). Line W14749.8 had 5.3% linolenic acid and 15.0% linoleic acid. At the M 4 and M 5 generations, its selfed progenies [W14749.8, since designated M3032 (ATCC 75021)] continued to exceed the statistical threshold for low C 18:3 with linolenic acid levels of 2.7% and 2.3%, respectively, and for a low sum of linolenic and linoleic acids with totals of 11.8% and 12.5%, respectively. The fatty acid composition of this low linolenic acid plus linoleic acid mutant, which was stable to the M 5 generation under both field and greenhouse conditions, is summarized in Table XII. In a single locations replicated yield trial M3032 was not significantly different in yield from the parent cultivar (Westar). TABLE XIII______________________________________Fatty Acid Composition of a LowLinolenic Acid Canola Line Produced by Seed Mutagenesis Percent Fatty AcidsGenotype C.sub.16:0 C.sub.18:0 C.sub.18:1 C.sub.18:2 C.sub.18:3 Sats______________________________________Westar 3.9 1.9 67.5 17.6 7.4 7.0W14749.8 4.0 2.5 69.4 15.0 5.3 6.5(M.sub.3)M3032.8 3.9 2.4 77.9 9.1 2.7 6.4(M.sub.4)M3032.1 3.5 2.8 80.0 10.2 2.3 6.5(M.sub.5)______________________________________ Sats = Total Saturate Content EXAMPLE 9 The high oleic acid mutation of A129 was introduced into different genetic backgrounds by crossing the selecting for fatty acids and agronomic characteristics. A129 (now renamed IMC 129) was crossed to Legend, a commercial spring Brassica napus variety. Legend has the following fatty acid compositions: C 16:0 --3.8%, C 18:0 --2.1%, C 18:1 --63.1%, C 18:2 --17.8%, C 18:3 --9.3%. The cross and progeny resulting from were coded as 89B60303. The F 1 seed resulting from the cross was planted in the greenhouse and self-pollinated to produce F 2 seed. The F 2 seed was planted in the field for evaluation. Individual plants were selected in the field for agronomic characteristics. At maturity, the F 3 seed was harvested from each selected plant and analyzed for fatty acid composition. Individuals which had fatty acid profiles similar to the high oleic acid parent (IMC 129) were advanced back to the field. Seeds (F 3 ) of selected individuals were planted in the field as selfing rows and in plots for preliminary yield and agronomic evaluations. At flowering the F 3 plants in the selfing rows were self-pollinated. At maturity the F 4 seed was harvested from individual plants to determine fatty acid composition. Yield of the individual selections was determined from the harvested plots. Based on fatty acid composition of the individual plants and yield and agronomic characteristics of the plots F 4 lines were selected and advanced to the next generation in the greenhouse. Five plants from each selected line were self-pollinated. At maturity the F 5 seed was harvested from each and analyzed for fatty acid composition. The F 5 line with the highest oleic acid fatty profile was advanced to the field as a selfing row. The remaining F 5 seed from the five plants was bulked together for planting the yield plots in the field. At flowering, the F 5 plants in each selfing-row were self-pollinated. At maturity the F 6 self-pollinated seed was harvest from the selfing row to determine fatty acid composition and select for the high oleic acid trait. Yield of the individual selections was determined from the harvested plots. Fifteen F 6 lines having the high oleic fatty profile of IMC 129 and the desired agronomic characteristics were advanced to the greenhouse to increase seed for field trialing. At flowering the F 6 plants were self-pollinated. At maturity the F 7 seed was harvested and analyzed for fatty acid composition. Three F 7 seed lines which had fatty acid profiles most similar to IMC 129 (Table XIII) were selected and planted in the field as selfing rows, the remaining seed was bulked together for yield trialing. The high oleic fatty acid profile of IMC 129 was maintained through seven generations of selection for fatty acid and agronomic traits in an agronomic background of Brassica napus which was different from the parental lines. Thus, the genetic trait from IMC 129 for high oleic acid can be used in the development of new high oleic Brassica napus varieties. TABLE XIII______________________________________Fatty Acid Composition of Advanced Breeding Generationwith High Oleic Acid Trait (IMC 129 X Legend)F.sub.7 Selections Fatty Acid Composition (%)of 89B60303 C.sub.16-0 C.sub.18-0 C.sub.18-1 C.sub.18-2 C.sub.18-3______________________________________93.06194 3.8 1.6 78.3 7.7 4.493.06196 4.0 2.8 77.3 6.8 3.493.06198 3.7 2.2 78.0 7.4 4.2______________________________________ The high oleic acid trait of IMC 129 was also introduced into a different genetic background by combining crossing and selection methods with the generation of dihaploid populations from the microspores of the F 1 hybrids. IMC 129 was crossed to Hyola 41, a commercial spring Brassica napus variety. Hyola 41 has the following fatty acid composition: C 16:0 --3.8%, C 18:0 --2.7%, C 18:0 --64.9%, C 18:2 --16.2%, C 18:3 --9.1%. The cross and progeny resulting from the cross were labeled 90DU.146. The F 1 seed was planted from the cross and a dihaploid (DH 1 ) population was made from the F 1 microspores using standard procedures for Brassica napus. Each DH 1 plant was self-pollinated at flowering to produce DH 1 seed. At maturity the DH 1 seed was harvested and analyzed for fatty acid composition. DH 1 individuals which expressed the high oleic fatty acid profit of IMC 129 were advanced to the next generation in the greenhouse. For each individual selected five DH 1 seeds were planted. At flowering the DH 2 plants were self-pollinated. At maturity the DH 2 seed was harvested and analyzed for fatty acid composition. The DH 2 seed which was similar in fatty acid composition to the IMC 129 parent was advanced to the field as a selfing row. The remaining DH 2 seed of that group was bulked and planted in plots to determine yield and agronomic characteristics of the line. At flowering individual DH 3 plants in the selfing row were self-pollinated. At maturity the DH 3 seed was harvested from the individual plants to determine fatty acid composition. Yield of the selections was determined from the harvested plots. Based on fatty acid composition, yield and agronomic characteristics selections were advanced to the next generation in the greenhouse. The DH 4 seed produced in the greenhouse by self-pollination was analyzed for fatty acid composition. Individuals which were similar to the fatty acid composition of the IMC 129 parent were advanced to the field to test for fatty acid stability and yield evaluation. The harvested DH 5 seed from six locations maintained the fatty acid profile of the IMC 129 parent (Table XIV). TABLE XV______________________________________Fatty Acid Composition of Advanced Dihaploid BreedingGeneration with High Oleic Acid Trait (IMC 129 X Hyola 41)DH5 of 90DU.146 at Fatty Acid Composition (%)Multiple Locations C.sub.16-0 C.sub.18-0 C.sub.18-1 C.sub.18-2 C.sub.18-3______________________________________Aberdeen 3.7 2.6 75.4 8.1 7.2Blackfoot 3.3 2.4 75.5 8.8 7.5Idaho Falls 3.7 3.1 75.0 7.5 8.1Rexberg 3.9 3.7 75.3 7.0 6.5Swan Valley 3.5 3.4 74.5 7.0 7.3Lamont 3.9 2.8 72.0 10.1 8.4______________________________________ APPENDIX A 1. "Seeds, Plants, and Oils with Altered Fatty Acid Profiles" (Docket No. BB-1017) ______________________________________Country Application No. Filing Date______________________________________USA 07/675,542 August 30, 1990USA 07/739,965 August 5, 1991USA 08/170,888 December 21, 1993PCT US91/05910 August 28, 1991Australia 91/084,363 August 28, 1991Austria X August 28, 1991Belgium X August 28, 1991Canada 2,089,265 August 28, 1991Denmark X August 28, 1991EPC 91915595.2 August 28, 1991France X August 28, 1991Great Britain X August 28, 1991Germany X August 28, 1991Greece X August 28, 1991Italy X August 28, 1991Luxembourg X August 28, 1991Netherlands X August 28, 1991Spain X August 28, 1991Sweden X August 28, 1991Switzerland X August 28, 1991______________________________________ 2. "Canola Variety Producing Seed with Reduced Glucosinolates and Linolenic Acid Yielding Oil with Low Sulfur, Improved Sensory Characteristics, and Increased Oxidative Stability" (Docket No. BB-1021) ______________________________________Country Application No. Filing Date______________________________________USA 07/767,748 September 30, 1991USA 08/140,206 November 12, 1993USA 08/290,660 August 15, 1994PCT US92/08140 September 30, 1992Australia 92/027,506 September 30, 1992Canada 2,119,859 September 30, 1992Denmark X September 30, 1992EPC 92921166.2 September 30, 1992France X September 30, 1992Great Britain X September 30, 1992Germany X September 30, 1992Netherlands X September 30, 1992Sweden X September 30, 1992______________________________________ 3. "Non Hydrogenated Canola Oil for Food Applications" (Docket No. BB-1060) ______________________________________Country Application No. Filing Date______________________________________USA 08/184,128 January 20, 1994PCT US94/04352 April 28, 1994Australia Y April 28, 1994Austria Z April 28, 1994Belgium Z April 28, 1994Canada Y April 28, 1994Denmark Z April 28, 1994EPC Y April 28, 1994France Z April 28, 1994Great Britain Z April 28, 1994Germany Z April 28, 1994Greece Z April 28, 1994Ireland Z April 28, 1994Italy Z April 28, 1994Japan Y April 28, 1994Luxembourg Z April 28, 1994Monaco Z April 28, 1994Netherlands Z April 28, 1994Portugal Z April 28, 1994Spain Z April 28, 1994Sweden Z April 28, 1994Switzerland Z April 28, 1994USA Y______________________________________ N.B.: "X" notation means country is designated in a pending application under the European Patent Convention for patent protection. "Y" notation means country is designated in a pending application under the Patent Cooperation Treating for patent protection. "Z" notation means country is designated in an EPC application designated in a pending application under the Patent Cooperation Treaty for patent protection.

Seeds, plants and oils are provided having low FDA saturates; high oleic acid; low linoleic acid; high or low palmitic acid; low stearic acid; and low linoleic acid plus linolenic acid; and advantageous functional or nutritional properties.

FIELD OF THE INVENTION This invention relates to the field of integrated circuit packaging and, more specifically, to an arrangement which allows multiple semiconductor chips to be housed in a single package. The invention is most particularly suited for plastic packaging of integrated circuits. BACKGROUND OF THE INVENTION Semiconductor integrated circuits, or chips, are small (usually square or rectangular) pieces of semiconductor material (e.g., silicon or gallium arsenide) with dimensions typically on the order of 2-7 millimeters on a side. Semiconductor chips may contain complex circuitry formed of hundreds of thousands of individual electronic components. Naturally, to utilize such a chip, connections must be made between the chip itself and external circuitry. To facilitate use of the chip and the making of such connections, the chip is usually packaged in a housing equipped with a lead structure incorporating electrical leads, each of which is at one end electrically bonded to the chip and at its other end serves as a connection point to other circuits. Inside the package, these leads are connected to individual terminal sites, known as bonding pads, on the chip. A variety of conventional techniques are available to accomplish this bonding. A leadframe typically carries only one chip. Thus, interconnections from chip to chip usually are made exteriorly to the chip package. While this provides flexibility in arranging interchip connections, there are situations in which such flexibility is unnecessary and adds to the cost of a product using the chips. Sometimes two chips are designed to be connected together in a particular fashion and advantages would accrue from connecting the chips within a single package, so that two chips could be sold as a single unit. Of course, there are instances when the circuitry on two smaller chips can be combined to be fabricated as a single chip in a single package. This is not possible, however, when the two constituent chips are manufactured using different process technologies. To assemble two chips on a single leadframe, the chips must be placed side by side on the leadframe's die attach paddle. However, this approach cannot be used with chips which are backside biased, unless their biasing needs are the same under all conditions. To solve this problem, some companies have removed the usual metal die attach paddle in the leadframe assembly and have replaced it with a dielectric substrate, onto which multiple chips may be mounted. The dielectric substrate is typically a ceramic or resin. The use of a dielectric is necessitated by the requirement to electrically isolate the substrates of the chips, so they may be separately backside biased. This solves the technical problem, but at considerable expense. Accordingly, it is an object of the present invention to provide an inexpensive technique for assembling multiple integrated circuit chips on a single leadframe. Another object of the invention is to provide a multiple chip mounting arrangement on a single leadframe which does not require removal of the metal die attach paddle of the leadframe or use of a dielectric substrate as a foundation for mounting the chips. SUMMARY OF THE INVENTION The foregoing objects are achieved in an assembly wherein the die attach paddle of a conventional leadframe is cut to form two electrically isolated die attach paddles and a dielectric tape is applied to one side of the two die attach paddles, spanning the space between them, providing physical support and substantially preventing cantilevered or twisting motion of the die attach paddles relative to the remainder of the leadframe assembly. The die attach paddles may not be electrically isolated in the strictest sense of that term until the various leads of the leadframe are separated from the side rails. Hence, it should be understood that when the die attach paddles are referred to herein as being electrically isolated, that term is meant to indicate that the die attach paddles will be electrically isolated once the side rails are removed and all metal bridges between the leads are cut. The invention will be more readily understood from the detailed description, which should be read in conjunction with the accompanying drawing. The detailed description is presented by way of example only, with the invention being defined only by the appended claims and equivalents thereto. BRIEF DESCRIPTION OF THE DRAWING In the drawing, FIG. 1 is a top plan view of a typical prior art leadframe strip or a plurality of leadframe assemblies used for production of integrated circuits in plastic packages; FIG. 2 is a cross sectional view of a single leadframe of FIG. 1, taken alone the lines 2--2 thereof, and showing in phantom two semiconductor chips p aced thereon; FIG. 3 is a top plan view of a partially completed leadframe assembly according to the present invention; FIG. 4 is a simplified cross-sectional view of the partially complete leadframe assembly of FIG. 3, taken alone the lines 4--4 thereof; FIG. 5 is a bottom plan view of a completed leadframe assembly according to the present invention; FIG. 6 is a top plan view of a completed leadframe assembly according to the present invention, with two chips mounted thereon; FIG. 7 is a simplified cross sectional view of the assembly of FIG. 6, taken alone the lines 7--7 thereof; FIG. 8 is an expanded layout of the apparatus of FIG. 6, showing the internal electrical connections established between the two chips o the leadframe assembly; and FIG. 9 is a top plan view of a leadframe assembly with four die attach paddles according to the present invention. DETAILED DESCRIPTION FIG. 1 shows a typical prior art leadframe strip 10, which is stamped from sheet metal. The leadframe strip 10 comprises a pair of side rails 12 and 14, each having sprocket holes, such as 16 and 18, at regularly spaced intervals. The sprocket holes cooperate during the chip assembly process with sprocket teeth in a mechanism for moving the leadframe strip through appropriate processing equipment. A leadframe strip generally has a large number of leadframe assemblies, such as the two assemblies 20 and 22, suspended between the side rails at regular intervals. Referring to representative leadframe assembly 20, each leadframe assembly comprises a die attach paddle 24 supported from the side rails 12 and 14 by thin metal bridges 26 and 28, respectively. A plurality of connection pins or leads 30A, 30B . . . 30n are also suspended between the side rails via bridges 31 and are arrayed around the die attach paddle. These connection pins are later bonded to small wires which connect them to bonding pads, or terminals, on the semiconductor chip(s). Later in the assembly process, the bridges 26, 28 and 31 are severed, detaching the side rails 12 and 14 from the connection pin strips and electrically isolating each of the connection pins and the die attach paddle. When two integrated circuit chips, such as chips 40 and 42, are mounted on opposite ends of die attach paddle 24, an arrangement such as that shown in FIG. 2 results. Since the die attach paddle is metal, chips 40 and 42 are, in such configuration, not electrically independent. If a bias voltage is applied to die attach paddle 24, it affects both chips 40 and 42. This, as noted above, is a situation that greatly restricts the flexibility of selecting two chips for assembly into the same package, since the two chips must be capable of operating with the substrate bias. Often, two chips which are to be closely interconnected must maintain independent biases. According to the present invention, this problem is solved as shown in FIGS. 3-8. The first step in creating the assembly of the present invention is to provide a modified leadframe assembly, wherein the attach paddle is formed as or cut into two (or more) separate die attach paddles, as indicated, for example, by the paddles 24A and 24B of FIG. 3. A single die attach paddle 24 may be cut into two or more constituent and electrically isolated die attach paddles, or die attach paddles 24A and 24B can be manufactured separately from the beginning. Separate die attach paddles 24A and 24B can be the same size or different sizes. For purposes of generality, they are indicated in the drawings to be of different sizes. The resulting arrangement appears in a simplified cross sectional view in FIG. 4, wherein the space 44 between the two die attach paddle members 24A and 24B is more apparent. Again, chips 40 and 42 which are to be mounted on the respective die attach paddles are shown in phantom and in diagrammatic form only. This structure 10 allows separate backside biasing of the two chips, but it is impractical. The leadframe is formed from a very thin sheet metal stock, so the bridges 26 and 28 (not shown in FIG. 4, but identical to those shown in FIG. 1) are inadequate to rigidly support the die attached paddles 24A and 24B which, due to the gap 44, are now cantilevered from the siderails. The twisting and moving of the two die attached paddles in that situation is intolerable. As a next step, therefore, in fabrication of the present invention, a strip of polyimide tape is applied, using a non conductive adhesive such as a silicone adhesive, to the reverse sides of the paddles 24A and 24B (i.e., the side which does not receive the chips). This is represented by the tape 50 in FIG. 5. A suitable material is Kapton® tape manufactured by E. I. duPont de Nemours of Wilmington, Del. After the polyimide tape has been secured, providing structural stability to the assembly, the two chips are glued to the top surfaces of the respective die attach paddles 24A and 24B, as shown in FIG. 6. The resulting arrangement is shown in the simplified cross-section of FIG. 7. Finally, the two chips 40 and 42 are wired to the connection pins, as shown in FIG. 8 by, for example, the wires 60A and 60B. They are also wired to each other by connecting appropriate conductors indicated generally at 62, between opposing bonding pads on the two chips. Lastly, the entire assembly is encapsulated in a plastic package. The polyimide tape may be obtained with an already applied coating of a pressure sensitive adhesive, so that it can simply be pressed in place. Alternatively, the polyimide tape may be secured to the die attach paddles with a heat activated adhesive. A prime benefit of this invention is its low cost. A total of 1-2¢ is added over the cost of the standard leadframe of the type shown in Fiq. 1. By contrast, the use of a ceramic substrate adds about 15-25¢ to fabrication costs, and the use of a resin substrate adds about 15 to fabrication cost. Up to four (or more) chips may be placed in a single package using this approach, using (for example) the arrangement shown in FIG. 9, where four separate die attach paddles 70A, 70B, 70C and 70D each have one bridge or tie bar (72A, 72B, 72C and 72D, respectively) connecting them to the side rail of the leadframe strip. A single strip of dielectric tape 74 may be applied across the backs of all the attach paddles. This can permit extremely complex functionality to be provided in a single package at low cost. Having thus described the inventive concept and two embodiments which are shown by way of example only, it will be readily apparent that various alterations, modifications and improvements will occur to those skilled in the art. Such alterations, modifications and improvements are intended to be suggested herein, although not expressly stated. Accordingly, the invention is limited only by the following claims and equivalents thereto.

The foregoing objects are achieved in an assembly wherein the die attach paddle of a conventional leadframe is cut to form two electrically isolated die attach paddles and a dielectric tape is applied to one side of the two die attach paddles, spanning the space between them, providing physical support and substantially preventing cantilevered or twisting motion of the die attach paddles relative to the remainder of the leadframe assembly.

TECHNICAL FIELD This invention relates generally to the control of radio frequency communication systems, and more particularly, to a system and method of optimizing utilization of a single channel or frequency of such a communication system. BACKGROUND OF THE INVENTION Much work has been done to optimize the access of communications media where the use of a single communications channel must be shared by a large number of users. Common techniques include time-division multiple access (TDMA), polling, token passing, token rings, random access with no sensing, random access with sensing, slot reservation and many others. These techniques have been used over telephone lines, satellite channels, coaxial cables, bus architectures and various types of radio links such as packet radio, cellular telephone, meteor burst, troposcatter and others. Each of these techniques has its own particular advantages and disadvantages. Any single approach will work well for the situation where the use fits the access method, but will not work as well where the traffic distribution is not optimum. In the field of mobile communications where the sites are not fixed, the traffic demands are irregular, and the link characteristics are dynamic and unpredictable. In previous installations of mobile radio frequency (RF) communications, a carrier-sense multiple access (CSMA) system has been used. As a particular unit gets data to transmit, it listens to the channel, sometimes called a link, to be sure no other unit is already transmitting. If the link is busy, the unit waits a random amount of time, then listens again. This is repeated until the link is thought to be free, then the unit transmits its channel acquisition request to the destination unit. The CSMA system works well where only a few units have data to transmit at any given time. In the CSMA system, there is a finite amount of time required to determine if the link is free, and once the unit begins a transmission sequence it can no longer determine if another unit is transmitting. Thus, when multiple units listen for a free link, there is a certain probability that at least two units will begin transmission at nearly the same time because both units determined that the link was free. This transmission collision usually causes both transmissions to be lost because the receiving units can not demodulate the data packets error free. Such collisions also occur when a unit cannot hear another unit that is transmitting and thus mistakenly believes a link is free. In an RF environment, the transmit power is high enough to damage the receiver unless the receiver is disabled during transmission. Therefore, a unit cannot monitor its receiver during its own transmission to determine if any other unit has transmitted and caused a collision. Thus, classic CSMA collision detection (CSMA/CD) modes can not be used. As discussed in Telecommunications Protocols and Design, by Spragins, J.D., Hammond, J.A., and Pawlski, K., Addision-Westly Publishing, 1991, this limits the channel utilization to less than 0.5 of the available bandwidth. This means that 50% of the transmissions in this type of network are lost. As the number of users increases, the result is that even more transmissions are lost. Another conventional technique to control communications over a single link is to reserve a time slot for each unit. With the slotted reservations system, a base unit (not shown) sends a reservation data packet or list to all remote units (not shown). The reservation data packet tells the remote units when they can each transmit and how long each can transmit. However, the slotted reservation system is not always effective because it only works when all units in any given area can receive each other's transmissions error free to allow them each to determine which unit has the link reserved in the next time slot. Many collisions can still occur. In addition, the slot reservation data packet itself takes up additional transmission time as well, thus reducing the system efficiency. Furthermore, a slotted reservation system may be very inefficient because time slots are allotted for remote units that have no data to transmit. Thus, the link may be unused for a significant percent of time. Therefore, it can be appreciated that there is a significant need for a system and method for efficiently controlling communication over a single link. The present invention provides this and other advantages as will become apparent through the following description and accompanying drawings. SUMMARY OF THE INVENTION The present invention is embodied in a system and method for the control of radio communications. The system comprises a plurality of remote radio units each having transmit and receive capability. Each of the remote units operates in a first mode to transmit a poll request signal to initiate communications and a second mode to transmit data. A base station also having transmit and receive capability receives a plurality of respective poll requests from the plurality of remote radio units and transmits a poll signal to at least some of the remote radio units. The poll signal includes a poll response sequence indicative of a particular time frame in which each of the remote radio units will respond to the poll signal. A poll detection unit in each of the remote radio units detects the poll signal. A control unit in each of the remote units controls transmission of the data in the particular time frame such that each of the remote radio units transmits data in the second mode in the time frame corresponding to the response sequence in the detected poll signal. In a preferred embodiment, the first mode of operation is a carrier sense multiple access (CSMA) mode. The system further includes a carrier sense circuit in each of the plurality of remote radio units to detect the presence of the carrier frequency. Each of the remote radio units delays random length of time if the carrier sense circuit detects the presence of carrier frequency and permits transmission in the CSMA mode only when the carrier sense circuit does not detect the presence of the carrier frequency. The system may also include a sequence list within the base station, with the sequence list containing data used to form the poll response sequence. The poll response signal from the remote radio units contains data indicative of the communications interval for each of the remote radio units. The poll detection unit receives the communications interval data and alters the sequence list accordingly such that a poll response sequence reflects the altered sequence list. The poll request signal from the remote radio unit may contain data indicative of a communications interval for each of the remote radio units. The base station periodically transmits the poll signal and the poll sequence is altered in each of the periodically transmitted poll signals in response to the communication data interval for each of the plurality of remote radio units. The poll signal may also include first and second portions, with the first portion including a plurality of synchronization data bits to indicate the start of the poll signal, and the second portion including the poll response sequence. In addition, the poll signal may include acknowledgment data bits for each of the plurality of remote radio units to indicate prior reception of the additional data from each of the remote radio units. The poll signal may also include an error check data portion at the end of the poll signal with each of the remote radio units including an error detection circuit to detect transmission errors using the error check data portion. Each of the remote radio units can periodically transmit the poll request signal to the base station, and the base station uses the periodically transmitted poll request signal to alter the poll response sequence. In a presently preferred embodiment, the system also includes a global positioning system receiver to receive position data. The position data is included in the additional data transmitted by the remote radio units. To help assure that radio communications is maintained between the remote radio units, the remote radio units transmit a data frame to the base station. The data frame has a frame synchronization sequence, a data portion, and an error detection portion. A threshold detector within the base station detects the signal strength of the received radio signals and a receiver lock circuit coupled to the threshold detector locks the base station onto a received radio signal containing data frames. The receiver lock circuit initially locks the base station onto a first received radio signal from a first remote radio unit and locks onto a second received radio signal from a second remote radio unit if the detected signal strength of the second received radio signal is greater than the detected signal strength of the first received radio signal by a predetermined level. A memory within the base station is sized to fit at least two data frames. The processor detects the frame synchronization sequences from the received radio signals and processes received data frames. The processor stores the received data frames in the memory and processes a first stored data frame received from the first remote radio unit beginning at the frame synchronization sequence and checking the data frame for an error using the error detection portion of the data frame. The processor accepts the first stored data frame if the error detection portion indicates that no error occurred. If the error detection portion of the first stored data frame indicates that an error occurred in the first stored data frame, the processor analyzes the memory to detect another frame synchronization sequence corresponding to a second stored data frame received from the second remote radio unit beginning at the frame synchronization sequence and checks the data frame for an error in using the error detection portion of the data frame. The processor accepts the second stored data frame if the error detection portion indicates that no error occurred. The processor accepts no data frame if the error detection portion indicates that an error occurred in the second stored data frame. In one embodiment, the error detection portion is a cyclic redundancy check code which the processor uses to determine whether a transmission error occurred in the first and second stored data frame. The remote units may also communicate with more than one base station using a single radio frequency. Each radio station uses a fixed synchronization data pattern to control communication with a remote radio unit. A first base station includes a first fixed synchronization data pattern and will communicate with remote radio units only if the remote radio unit uses the first fixed synchronization pattern. A second base station uses the second fixed synchronization data pattern different from the first fixed synchronization data pattern to control communication with tile remote radio unit. The second base station communicates with the remote radio unit only if the remote radio unit uses the second fixed synchronization data pattern. A receiver portion in the remote radio unit receives signals from both the first and second base stations. The receiver portion determines signal strength from the received radio signals from both the first and second radio stations and selects either the first or second base station for subsequent transmissions based on the signal strength. The remote radio unit transmits the frame synchronization portion of the data frame, which includes the first fixed synchronization data pattern if the receiver portion determines that the signal strength from the first base station was greater than the signal strength frown the second base station and includes the second fixed synchronization data pattern if the receiver portion determines that the signal strength from the second base station is greater than tile signal strength from the first base station. In this manner, the remote radio station can communicate with either the first or second base station. The remote radio unit may also switch between the first and second base stations. The receiver portion continues to monitor the received radio signals from the first and second base stations, and alters the included fixed synchronization data pattern if the signal strength from the first and second received radio signals changes. In this manner, the remote radio unit switches base stations with which it is communicating. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating the cell interleaving of the present invention. FIG. 2 is a block diagram of the communication system of the present invention. FIG. 3A is a functional block diagram of a base station of the present invention. FIG. 3B is a functional block diagram of a remote unit of the present invention. FIG. 4 is a TDMA poll synchronization timing diagram used by the system of the present invention. FIGS. 5A and 5B together are a flowchart of the network level operation of the remote units of the system of FIG. 3B. FIG. 6 is a flowchart of the network level operation of the base stations of the system of FIG. 3A. FIGS. 7A and 7B are flowcharts of the operation of the remote units of FIG. 3B when interacting with the base stations of FIG. 3A. FIGS. 8A and 8B are flowcharts of the operation of the base stations of FIG. 3A when interacting with the remote units of FIG. 3B. FIG. 9 is a diagram illustrating the capture of a high level signal by the base stations of FIG. 3A. FIG. 10 is a flowchart of the operation of the base stations of FIG. 3A illustrating the capture of a high level signal. FIG. 11 is a flowchart illustrating the operation of the remote units of FIG. 3B to operate with multiple base stations. DETAILED DESCRIPTION OF THE INVENTION The present invention is capable of controlling communications among a plurality of transmitters on a single frequency. The transmission frequency, sometimes called a channel or link, is utilized at a high efficiency. The invention performs various functions such as: (1) managing network connectivity to allow remotes to roam freely within an infrastructure of base stations; (2) using a combination of CSMA and TDMA modes of operation; (3) changing operating modes efficiently; (4) capturing the transmissions of contending units as much as possible when collisions do occur; and (5) reducing the contention between devices in close proximity and devices located distantly. The communication system utilizes a series of base stations and a large number of remote units. The base stations provide a large overlapping area of coverage, as illustrated in FIG. 1. The different areas of coverage are illustrated as cells C1 to C7. The term "cell" is frequently used to describe a communications network, such as a cellular telephone system, where there is a control site within each cellular telephone cell. However, the present invention is significantly different from a cellular telephone system. The different cells in the cellular telephone system operate at different frequencies or channels and each cellular telephone changes channels depending on the particular cell in which it is operating. In contrast, the cells C1 to C7 of the present invention all operate on the same frequency or channel. All radio transmission in all cells C1 to C7 operate on the same channel. Each of the cells C1 to C7 contains a single base station 2, which communicates with a large number of remote units 6. For the sake of simplicity, only a few of the remote units 6 are shown in FIG. 1. However, in a typical installation, there may be dozens or hundreds of remote units 6 operating in the cells C1 to C7. The cells C1 to C7 may also be grouped into regions R1 and R2, indicated by the dashed lines in FIG. 1, to provide broader regional control of the communications network. As will be described in detail below, the base stations 2 within the region R1 are configured to ignore radio transmissions from base stations and remote units 6 in the region R2. As shown in the functional block diagram of FIG. 2, the base stations 2 are linked to a central computer system 8 through high speed data links 10, such as dedicated telephone lines, satellite links or microwave links. The base stations 2 are installed far apart from one another in locations that provide coverage over all portions of the topology to be serviced. Although the cells C1 to C7 in FIG. 1 are illustrated as circular, it is apparent that the actual coverage may vary from one cell to the next. For example, geographical features, such as mountains, will alter the pattern of coverage. The present invention is clearly not limited to the circular coverage illustrated in FIG. 1. Furthermore, the present invention is illustrated with seven cells C1 to C7. However, the present invention can work with more or less cells and is not limited to the specific example of seven cells. An explanation of terminology used in the present description will assist the reader in understanding the invention. Base stations 2 are typically fixed-location, ground based RF modems that are connected to the computer system 8. In a normal installation, there is one base station 2 in each cell C1 to C7. Remote units 6 are mobile RF modems that are installed in mobile vehicles, ships and aircraft or are transportable and can be erected in the field. Because the remote units 6 are mobile, there is a variable number of remote units 6 within each cell C1 to C7 at any given time. The number of remote units 6 in any of the cells C1 to C7 can change quickly. For example, the remote unit 6 may be installed in an aircraft that moves from one of the cells C1 to C7 to the next at high speed. The base stations 2 do not need to communicate with one another except where the installation of a repeater 14 is necessary at a location where there is no access point into the high speed data link 10. The repeater 14 is a RF device that receives data from one or more remote units 6 and relays (or repeats) the data to the base station 2 to which the repeater is assigned. The repeater 14 acts like a base station 2 as far as communicating to remote units 6 is concerned, but routes all data destined for the central computer system 8 to its assigned base station. The repeater 14 to base station 2 links are to be minimized as they will need to use the CSMA transmission time to relay data from remote units 6 to base stations. Alternatively the repeater 14 could be used to relay data from a base station 2, which has no access to the high speed data link 10, to another location, such as a different base station, that does have access to the high speed data link. Once the base stations 2 have received data from the remote units 6, conventional techniques are used to communicate between the base station 2 and the central computer system 8. The present invention is directed to the control of communications between the remote units 6, the base stations 2, and repeaters 14. The present invention is embodied in a system 30 illustrated in the functional block diagrams of FIGS. 3A and 3B. The system 30 includes base stations 2 (FIG. 3A) and re,note units 6 (FIG. 3B). The base station 2 illustrated in FIG. 3A includes a transmitter 32 and receiver 34, which are coupled to an antenna 36. The transmitter 32 and receiver 34 are used to transmit and receive digital data and may be termed a RF modem. The base station 2 also includes a central processing unit 38 and a memory 40, which may include both random access memory (RAM) and read only memory (ROM). The memory 40 also includes a data buffer 40a. A display 42 and user input device 44 are coupled to the CPU 38 by a bus 46, which may carry power and control signals as well as data. A polling table 48 is used to keep track of the remote units 6 currently communicating with the base station 2. The polling table may be part of the memory 40. The operation of the polling table 48 will be discussed in detail below. The system 30 includes software in the memory 40 that controls the base station 2 and causes it to perform in accordance with the present invention. The system 30 also includes remote units 6, illustrated in FIG. 3B. The remote units 6 contain many of the same components described above for the base station 2. For the sake of brevity, the description of these components will not be repeated. In a presently preferred embodiment, the remote units 6 also include a global positioning system (GPS) receiver 50, which is coupled to an antenna 52. Certain components of the system 30, such as the transmitter 32, receiver, 34 and GPS receiver 50 are well known in the art and need not be described in detail. The system 30 utilizes a combination of TDMA and CSMA operating modes to provide collision avoidance. The remote units 6 can easily switch between the two operational modes. Each base station 2 in the same region uses a correlation code that permits it to communicate only with remote units 6 using the same correlation code. For example all remote units 6 communicating with the base station 2 in cell C3 in region R2 will uses the correlation code associated with the region R2. This prevents the base station 2 in cell C3 from inadvertent communication with remote units 6 currently assigned to the base station 2 in the region R1. It should be noted that the remote units 6 are not restricted to communication only with the base station 2 in whose cell the remote unit is located. For example, the terrain may prevent the remote unit 6 in cell C1 from communicating with the base station 2 in cell C1. However, the base station 2 in cell C4, also in region R1, may be able to communicate with the remote unit 6. Each remote unit 6 can change its correlation code to switch communication to a new base station 2 in a different one of the cells C1 to C7 or regions R1 and R2. In this example, the remote unit 6 in the cell C3 in region R2 alters its base identification code and correlation code to match the base identification and correlation code of the base station 2 in the cell C1 in region R1 and communicates with that base station. This permits remote units 6 to freely communicate with the base station 2 that can most effectively process the communications. In another inventive aspect, the base station 2 will attempt to lock onto the strongest signal and communicate with the remote unit 6 transmitting the most powerful signal. In a conventional system, the two competing or colliding signals will cause a reception error and neither signal will be properly processed. With the system 30, if a collision does occur, the base station 2 will lock onto the more powerful signal. However, data from both received signals are stored in a data buffer 40a. The base station 2 then analyzes the received data in the data buffer 40a to recover data from the more powerful transmission. The various components of the system 30 and their operation may now be discussed in greater detail. Each base station 2 is assigned a polling interval that does not overlap or conflict with the base stations in adjacent cells C1 to C7. Polling intervals in adjacent cells are interleaved to minimize contention during the time each base station 2 polls the remote units 6 operating within its cell. For example, base station 2 in cell C5 might poll at a 30 second interval starting at offset 10 seconds in each 30 second interval with a duration of 5 seconds. Another base station 2 in cell C6 could then poll at a 30 second interval starting at offset 0 seconds in each 30 second interval with a duration of 5 seconds. The interval width and offset from the first second of each minute can be set as required for a particular system topology and expected data loading. The polling interval and duration is configured into each base station 2 on installation. However, the polling interval and duration can be changed by the central computer system 8 by simply transmitting new configuration data to the base stations 2. Thus, the system 30 can be dynamically reconfigured to accommodate changes in the data loading. The base stations 2 in this type of network need to be time-synched. This is accomplished periodically by a network monitor function that runs in the central computer system 8. The central computer system 8 periodically transmits the time of day to the base stations 2. This procedure maintains time synchronization to approximately±1 second. The system 30 does not require more precise (e.g., microsecond) accuracy because there is typically additional time between the end of a polling transmission and the designated duration so that precise timing is unnecessary. In addition, the system 30 selects the polling interval so that adjacent cells C1 to C7 do not poll in adjacent time frames. For example, the polling interval for the cell C3 may be followed by the polling interval for the cell C6 so as to minimize potential collisions if the base station in the cell C3 polling transmission extends into the polling interval for the base station in the cell C6 or if the base station in the cell C6 begins transmitting early due to the less precise time synchronization. The remote units 6 detect which base stations 2 it can receive and chooses one base station to communicate with. The remote unit 6, using the CSMA protocol, acquires the RF channel and transmits its TDMA channel request to the base station 2. Although a transmission collision is possible, it is relatively unlikely because the small amount of data that must be transmitted in a TDMA channel request requires only a short transmission time. In addition, the use of random time delays in the CSMA mode, combined with the short transmission time, minimizes the chances of a collision. The base station 2 registers the remote unit 6 as one to poll, inserts the necessary data into its polling table 46 and acknowledges the transmission from the remote unit. Any previous base station 2 that was polling that remote unit 6 will not receive data from the remote unit and will time it out, and remove it from its polling table 46. Thus, only one base station 2 at a time will communicate with any remote unit 6, and it is the remote unit that determines which base station it wants. If the remote unit 6 fails to get acknowledgments or polls from its selected base station 2 for a predetermined period of time, the remote unit will start the process again by choosing a different base station. This will be necessary when the remote unit 6 goes out of range from its selected base station 2, or if the RF link is not reciprocal due to local noise and terrain effects. The polling table 46 in the base station 2 is updated each time a remote unit 6 moves to a different base station. The polling tables 46 in each base station 2 are used by the central computer system 8 for routing outbound message packets to the remote units 6. The central computer system 8 gives a message to the last base station 2 to have communication with the destination remote unit 6. The base station 2 then uses network tables 8a in the central computer system 8 to find the shortest path to the destination remote unit 6. The network tables 8b are the lists of remote units 6 with which the base station 2 is communicating. The central computer system 8 has a master list of all remote units 6 that are currently communicating with base stations 2 and identifies which base station is communicating with which remote units. For example, the central computer system 8 may wish to deliver a message to a particular remote unit 6. The central computer system 8 uses the network tables 8a to determine which base station is currently communicating with the destination remote unit 6 and will route the message to the destination remote unit 6 using the base station 2. It should be noted that the central computer system 8 may route the message indirectly to the destination remote unit 6. This may include routing through repeaters 14 (see FIG. 2) as well as multiple remote units 6 to deliver the message to the intended destination. The base stations 2 and remote units 6 use a combination of the CSMA and TDMA modes to allow the transmission of less frequent unsolicited data, and the transmission of very frequent high volume data. The conventional CSMA mode allows transmission of low volume, less frequent data. The persistence that each remote unit 6 uses to gain access to the channel is fixed at a level that reduces the probability of collision, but increases the delay between transmissions to allow several hundred remote units to share the channel. The TDMA mode is used to allow the transmission of high volume, more frequent data, by multiplexing the channel among all the remote units 6 that have data ready to transmit without wasting transmission time for those remote units that do not have data to transmit. The TDMA mode provides a fixed time slot for each remote to transmit in, thus eliminating collisions. The system 30 synchronizes time slots for TDMA communication in a manner that does not depend on each remote unit 6 having an expensive time clock. The transmit bit clocks of the remote units 6 have to be closely aligned to the desired bit rate, but each poll received from the base station 2 will resynchronize each remote unit 6 from the time it received the last bit of the poll frame. The timing diagram of FIG. 4 shows poll transmissions 600 and 602 from the base station 2. The response frames 604 and 608 of the remote units 6 are also shown in FIG. 4. Each remote unit 6 will transmit its response repeatedly within the response window, but will not key (turn on) its transmitter 32 (see FIG. 3B) until its particular slot time. For example, the first remote unit 6 keys its transmitter 32 in time slot 1. The second remote unit 6 transmits its response in time slot 1 with its transmitter 32 off, then transmits its response again in time slot 2 with its transmitter turned on, and so forth. Thus, each remote unit 6 continuously transmits its data in each time slot to maintain the proper timing relationship with the other remote units. At its designated time slot, the remote unit 6 keys or activates its transmitter 32 to actually transmit the data frame to the base station 2. An example of the type of data used in the TDMA slot scheduling by the system 30 is shown in FIG. 4. The data used in the example of FIG. 4 is position data from the GPS receiver 50 (see FIG. 3A) from remote units 6. This example is at 4000 bits per second, making the time to transmit a single 8-bit byte equal to 2 milliseconds. A poll frame 610 is transmitted from the base unit 2. The poll frame 610 includes 5 bytes of l's, a 3 byte correlation pattern, 24 bytes of poll data 612 and a 16 bit CRCC value. The poll data 612 is expanded to show its components. The poll data 612 includes a frame type byte indicating the type of data being transmitted, a 16 bit identification (ID) of the polling base station 2, an 8-bit frame sequence number which is incremented for each transmission, a 4-bit count of the number if lD's in the ID field (max.=10 in this example), 12 acknowledge (Ack) bits, with only 10 Ack bits being used in this example, where each Ack bit corresponds to one of the response frames received from remote units 6 in the preceding poll slot, and from 1 to 10 16-bit remote ID codes of the remote units that are to respond to this particular poll frame. In response to the poll signal 600, the remote units 6 transmit their data in a time sequenced series of response frames 608. The details of the individual remotes response frame 608 are shown at 620. Each response frame 622 includes 5 bytes of 1's, the 3 byte correlation pattern, a response data field 622, and a 16 bit CRCC code. An example of the data field 622 for GPS data is shown in FIG. 4. The data field 622 for GPS data includes an 8-bit frame type code indicating the type of data being transmitted by the remote unit 6, a 16 bit ID of the base station 2 to receive the response frame 620, the 16 bit ID of the remote unit 6 sending this particular transmission, a 16 bit ID of the network unit that the data is to be routed to, a 24 bit data and time code of when the GPS data was read, a 32 bit latitude, a 32 bit longitude, a 16 bit speed, a 16 bit heading, a 16 bit altitude, a 8-bit status code, and a 16 bit polling request interval. Those skilled in the art will recognize that the system 30 is not limited to data types illustrated in the specific examples presented herein. To orchestrate the changes in operating mode as efficiently as possible, each base station 2 uses the polling table 46 (see FIG. 3A) to maintain a list of remote units 6 that are currently requesting to send a high priority, time-critical, data packet of a known type and length. There can be any number of different types, with different types of data packets requiring different slot sizes. The base station 2 keeps the requested interval from each remote unit 6 in the polling table 46 as well. The remote unit 6 sends its request for TDMA service to the base station 2 using the lower priority CSMA mode of operation. The request contains the data type and desired transmission interval. This one request is all that is required until the remote unit 6 chooses a different base station 2. The base station 2 will then schedule the remote unit 6 in its TDMA polling interval as often as required to meet the service level requested by the remote unit. When a timer (not shown) in the base station 2 indicates it is time to allow remotes to transmit this critical information using the TDMA mode, the base station senses a free channel in the CSMA mode, then transmits a poll frame that contains the data type and a list of ID numbers of the remote units 6 that will be allowed to transmit, as shown in FIG. 4. Each of the remote units 6 that receives the poll transmits its data, of the corresponding type, in a slot that is determined by the position of its ID in the poll frame and for a maximum time indicated by the polled data type. Note that remote units 6 do not depend on hearing the other remote units in the list transmit their data as the other remote units may be out of range or blocked by the terrain from each other while they each can hear the base station 2. Each remote unit 6 can transmit its response at the correct time by transmitting its data in all of the slot positions, but only keying the RF transmit power in the transmitter 32 (see FIG. 3B) when the desired slot is being transmitted. Any other remote units 6 that receive the poll, but do not see their ID in the poll list, hold off their CSMA transmissions long enough for all of the poll responses to be completed, thereby eliminating any chance for collision. Each poll frame is numbered with an increasing sequence number and contains acknowledgment bits that correspond to slot positions for which data was correctly received in the previous poll interval. The acknowledgment bits and poll sequence number lets the remote units 6 know if their previous data transmission was received correctly by the base station 2. If it was not, the remote unit 6 waits for another poll containing its ID number to transmit the data again. Typically, each poll sequence will allow for at least 10 response slots for each poll, but any number may be used. The base station 2 works its way through its polling lists until all data has been received correctly. The base station 2 will then wait for the next polling interval before repeating the process again. The time between polling sequences is utilized for normal CSMA type transmissions. The network functions of the remote units 6 provide the capability for each remote unit to independently choose its own base station 2. The operation of the remote unit 6 to select the base station 2 and receive data from the base station is illustrated in FIG. 5a. At the start 100, the remote unit 6 powers up with no base station 2 selected. This is indicated at decision 102 with the remote unit 6 determining whether any base station has been selected with a parameter "Mybase" indicating the selected base station 2. If a base station 2 has been selected, the result of decision 102 is NO, and the system 30 moves to decision 104 to test whether it has timed out. If a time-out has occurred, the result of decision 104 is YES and the system 30 resets the parameter Mybase in step 106 and returns to decision 102 to initiate the selection of a new base station 2. As long as the base station 2 has been selected and it has not timed out, the system 30 remains in the loop between decision 102 and decision 104 and maintains communication with the selected base station. Each time the remote unit 6 receives communications from the base station 2, the time-out will be renewed. If there is no base station 2, then decision 102 branches to decision 108 where a check is made to determine if a new base station should be chosen. This is normally done only once a minute to give the remote link level time to accumulate some receptions from any base stations 2. If it is not time to choose a new base station 2, the result of decision 108 is NO and the system 30 loops back to decision 102. If it is time to select a new base station 2, the result of decision 108 is YES and the system 30 moves to decision 110 to determine if a base list exists. The base list is a list of base stations 2 from which the remote unit 6 is receiving RF transmissions as well as an indication of the strength of the received RE transmissions. It should be noted that tile base list at decision 110 will exist if the link level has received some transmissions from base stations 2. In step 114, the remote unit 6 searches the base list for the base station 2 with the strongest average signal level. The base station 2 with the highest average signal level is selected for communication with the remote unit 6 and the parameter Mybase is set to the selected base station in step 114. In step 116, the remote unit 6 deletes the base list. Thus, the remote unit 6 receives transmissions from one or more base stations 2 and determines the base station with which it will communicate. It will communicate with the selected base station 2 until there is a loss of communications with that base station that results in a time-out and the selection of a new base station. The technique used by the remote units 6 to receive data frames from the base station 2 is also illustrated in FIG. 5B. The process of receiving data frames in the remote unit 6 is used in several other portions of the system 30. For the sake of brevity, subsequent references to the reception of data frames illustrate the process as a single step. For example, the step "RXFRAME" is shown in the flowcharts of FIGS. 7A, 7B, 8A, and 8B. Moreover, it should be understood that references to the single step "RXFRAME" involves the steps illustrated in the flowchart of FIG. 5B. The process of receiving data frames begins at 130. The process illustrateted steps 130 to 146 is used to wait for a given number of milliseconds to listen for a valid reception from another remote unit 6. At step 132, the remote unit 6 sets up a timing loop to continue searching until tile time has elapsed. The time-out value of the timing loop is provided by the calling routine and depends on what state the process is in. In step 134, the system 30 searches for a valid correlation pattern to find the next beginning of frame sequence and frame type code. The details of the correlation pattern and frame sequences are provided below. In decision 136, the system 30 determines whether a frame sequence is found. If a frame sequence has been found, the result of decision 136 is YES and the system 30 receives the remaining portions of the data frame in step 138. If no frame sequence was found, the result of decision 136 is NO, and the system 30 flow branches to step 144. The length of the data frame will depend on its type, and the CRCC is usually the last two bytes of the data frame. In decision 140, the system 30 tests for a valid CRCC. If the CRCC is valid, the result of decision 140 is YES and the data frame subroutine returns a "good" flag to the calling routine in step 142. If the CRCC was not valid the result of decision 140 is NO. In that event the system 30 moves to decision 144 to determine if a time-out occurred. If a time-out has not yet occurred, the result of decision 144 is NO and the system 30 loops back to step 132 to continue trying to find a good data frame. If a time-out has occurred, the result of decision 144 is YES and the system 30 returns a time-out flag to the calling routine in step 146. The base station 2 also processes data frames to be transmitted to the remote units 6 and received from the remote units. The operation of the base station 2 to process data frames is illustrated in the flowchart of FIG. 6. The base station 2 begins its network processing at a start 150. A one second delay is shown at step 152 to indicate that some small time can pass between iterations of the loops. At step 154, the network table (not shown) is used to look at the status of each remote unit 6. The network table is a list of the remote units 6 with which the base station 2 is currently communicating. It should be noted that the central computer system 8 (see FIG. 2) contains a list of all remote units 6 currently operating and the identification of the base stations 2 with which the remote units are communicating. Each base station 2 also maintains a network table, but only for the particular base station. However, the central computer system 8 may query the network table in the base station 2 to determine with which base station a particular remote unit 6 is currently in communication. In decision 156, the base station 2 determines whether the time from the last reception from any remote unit 6 has exceeded a remote-down time-out. If the remote-down time out has been exceeded for any remote unit 6, the result of decision 156 is YES, and the system 30 removes that remote unit from the poll list in step 158 removes the remote from the polling table 46 (see FIG. 3A). In step 164, the system 30 removes that remote unit 6 frown the network table. When the remote unit 6 is removed from the network table in the base station 2, the base station will no longer communicate with the particular remote unit. In addition, the base station 2 reports the change in the network table to the central computer system 8 (see FIG. 2), which updates the central network table. It should be noted that, when the remote unit 6 switches to communication with another base station 2, that base station will update its own network table and relay the change in status to the central computer system 8, which updates its network table. The end of the list is tested at decision 166. The existence of new remote units 6 is tested for in decision 160. If there is a new remote unit 6, its time-out is initialized, its ID is added to the network tables and its polling interval is added to the polling table 46 in step 162. The polling table 46 is checked at decision 168 to see if any remote unit 6 needs to be polled. If not, then the system 30 loops back to step 152. It should be noted that each remote unit 6 has previously requested its own polling interval. If any remote unit 6 needs to be polled, the result of decision 168 is YES and the base station 2 initiates the polling process. The base station 2 must determine which remote units 6 are to be polled in the current cycle. Some remote units may have requested a long polling interval while other remote units may have requested a short polling interval. Thus, for a given polling cycle, not all remote units 6 will be polled by the base station 2. If some polling is required, a nested process begins at step 170 to loop for each type of polled data. There may be many different types of polled data, with each data type having its own frame format and size. At step 172, the system 30 computes the number of remote units 6 to poll. Typically the remote units 6 are polled in fixed size groups (10 for example) until all have been serviced. When all poll types have been completed at step 184, the process starts again at step 152. The process of polling individual groups is described in steps 174 to 182. At step 174 each group of remote units 6 is sequenced for each particular poll type. The poll complete flag is cleared at step 176, then the base station 2 signals the link level to poll the group of remote units 6 in step 176. At decision 180, processing waits for completion of the poll by the link level, or a time-out if the link level can not complete the poll as requested. If the end of the polling interval for the base station 2 is reached or their time-out occurred, the polling loop is stopped at decision 181. At decision 182, the base station 2 checks the end of the remote list, and the next group is polled until all groups are completed. When all groups have been polled, the base station begins the process again at step 152. The interaction of the remote unit 6 with the base station 2 is designated as a remote level link, and is described in the flowchart of FIGS. 7A and 7B to 7C. The remote link level starts at 200 in FIG. 7A, with the re,note unit 6 choosing an initial random delay value at step 202. As previously discussed, the CSMA mode operates by randomly checking for a free link when the remote unit 6 wants to transmit message frames. If the remote unit 6 has not designated a base station 2 with which to communicate, this is detected at decision 204 and the system 30 moves to decision 240 in FIG. 7B to select a base station. Until a base station 2 has been selected, the remote unit 6 cannot transmit. However, if the remote unit 6 is unable to identify a particular base station 2 with which to communicate, the remote unit can perform a network-wide transmission, which can be received and processed by base station or remote unit. The remote link level must help the network level find a base station 2 by listening for transmissions from base stations at steps 242, 244, 246, and recording the signal levels of each base station at step 248. The base stations ID's and signal levels are put in a base list at step 254 if they are larger than the previous signal level value for that base station at decisions 250 and 252, and step 256. Once a base station 2 has been selected, the remote unit 6 listens for a specified amount of time at step 206 and determines if the link is busy or not. If a data frame is received at decision 208, the link is not free and the received frame is checked for destination and type at decision 210. If the frame type is a poll from the base station 2, it is checked at decision 220 to see whether the ID for the remote unit 6 is in the poll. If ID for the remote unit 6 is in the poll, then step 222 determines which slot will be used for the transmission of data from the remote unit and resets the poll and base time-outs. The slot number corresponds to the position of the remote ID in the poll frame. The proper poll response is set up at step 226 if a response is available from the remote unit 6 or step 228 if the response is not available from the remote unit. The remote unit 6 transmits its response in the correct time slot. The use of time slots for responses by the remote unit 6 will be discussed in detail below. If the ID for the remote unit 6 is not in the poll frame at decision 220, then decision 230 determines if this poll is an acknowledgment of the last poll response by the remote unit. The remote unit makes this determination by checking the sequence number and Ack bits in the poll frame transmitted by the base station 2. The sequence number will be one greater than the last poll responded to if the last transmission was acknowledged. The Ack bits will be sequenced to indicate which of the multiple responses were received correctly in the last poll response window. If it was an acknowledge response, the data is cleared at step 231, otherwise it is left ready to transmit again on the next poll from the base station 2. If the frame type received from the base station 2 at decision 210 is not a poll frame, and if it is a valid message frame for this remote unit 6 as determined by decision 211, the remote unit processes the data frame as a message in step 212. Decision 214 determine whether the remote unit has data to transmit to the base station. If there is data to transmit to the base station 2, the remote unit 6 transmits the next message frame at step 216 otherwise the base station transmits an acknowledge frame at step 218. Returning again to decision 208 in FIG. 7A, if the data frame is not received, the resulted decision 208 is NO. In that event, the remote unit 6 increments the poll timer and base time out in step 260, shown in FIG. 7B. In decision 262, the base station 2 determines whether the poll timer is has exceeded the poll interval. If the poll timer has not exceeded the poll interval, the resulted decision 262 is NO and, in step 264, the remote unit 6 queues poll data and poll interval for transmission as a message frame to the base station 2. Following step 264, the remote unit 6 returns to decision 204 in FIG. 7A. If the poll timer did exceed the poll interval, the result of decision 262 is YES. In that event, the remote unit 6 determines whether the random delay time has expired in decision 266. If the random delay time has not expired, the result of decision 266 is NO, and the program returns to decision 204 in FIG. 7A. If the random delay time has expired, the result of decision 266 is YES. In that case, in decision 267, the remote unit 6 determines whether there are any messages to transmit from the remote unit to the base station 2. If there are no messages to transmit to the base station 2, the result of decision 267 is NO, and the remote unit 6 returns to decision 204 in FIG. 7A. If the remote unit 6 has a message to transmit to the base station 2, the result of decision 267 is YES. The loop from steps 268 to 282 shown in FIG. 7C describe the transmission of a message between the remote unit 6 and the base station 2. In step 266, the remote unit 6 transmits a message frame to the base station 2. In step 270 the remote unit waits to detect a received frame from the base station 2. In decision 272, the remote unit 6 determines whether the received frame is an acknowledgment frame. If so, in step 274, the remote unit 6 clears the last transmitted message frame and returns to step 266. If the received frame was not an acknowledgment frame, the remote unit 6 moves to decision 276 where it determines whether the received frame was a message frame. If the received frame was a message frame, the remote unit 6 clears the last transmitted message frame in step 278 and processes the newly received frame in step 282. Following the processing of the received frame, the remote unit 6 returns to step 266. If the received data frame was not a message frame, the result of decision 276 is NO, and the remote unit 6 chooses a new random delay time in step 280 and returns to decision 204 in FIG. 7A. The interaction of the base station 2 with remote units 6 is designated as the base link level operation and is described in the flowchart of FIGS. 8A and 8B. The base station 2 operates in CSMA mode until a remote unit 6 needs to be polled and while receiving message frames from the remote units. Then the base station 2 switches to TDMA mode to complete any polling cycles. Lastly the base station 2 switches back to CSMA mode again. This process is described in detail starting at 300 in FIG. 8A. The initial CSMA random delay value is chosen at step 302. The random delay is tested at decision 330, and a new value chosen at step 338. As described above for the remote unit 6, a free link is sensed at step 304 by waiting to receive a data frame. If a data frame is not received the link is free and flow goes to decision 328 in FIG. 8B to check for a group poll signaled frown the network level at step 170 (see FIG. 6). If there is no group poll and the random delay is expired at decision 330, then the base station 2 can transmit a CSMA data frame. It checks all the remote units 6 in its network table in step 332 and decision 334 and 336. If there is a message to send to one of the remote units 6, the result of decision 334 is YES and the base station 2 executes the loop from step 354 to decision 366 to transmit to the desired remote unit. This process begins with an immediate transmission of the first message frame to the remote unit 6 at step 356, then listening for a reply from the remote at step 358. If there is a reply, decision 360 is satisfied and the reply is tested to determine if it is an acknowledgment of the transmission in decision 360, or if it is another message frame coming from the remote unit 6 in decision 368. Both cases are treated as an acknowledgment with the base station 2 clearing the last transmitted message frame at steps 364 and 370. If the reply from the remote unit 6 is another message frame, the base station process the new message frame at step 372. The message exchange continues until an error breaks the link, or until both the base station 2 and remote unit 6 run out of message frames to exchange, as determined in decision 366. Returning again to decision 328, if there was a group poll scheduled, then the base station 2 builds a poll frame at step 340 consisting of ID's for up to "n" remote units 6 and a poll type code. The maximum number of remote units 6 polled in each group is determined by how long the remote units can remain in bit-sync, and by the desired efficiency level. As more remote units 6 are polled, the ratio of response bits to poll bits gets larger. The poll frame is transmitted at step 340, then a loop from step 342 to decision 350 is executed to receive the responses from the remote units 6. Each response frame is received iu step 344. The base station 2 must be able to receive responses from remote units 6 later in the response frame even if errors are found in the earlier responses of remote units. Once all the responses are received as determined in decision 350, or if there is a time-out in the receive frame process of step 346, the network level is notified the poll group is complete at step 347 if no more data frames are received in decision 346 and by step 352 if decision 360 determine that there are no more message frames. The time-out is computed by multiplying the number of remote units 6 to poll by the duration of each response frame which may differ for each poll type. Returning again to FIG. 8A, if a remote message frame is received from a new remote unit 6 at decision 308, then the ID for the new remote unit is added to the network tables for the network level to set up at 160 (see FIG. 6). Also, at step 312 the time-out for each remote unit 6 is set to zero to keep the remote unit in the active network and polling table 46 (see FIG. 3A) as long as it keeps responding. At decision 314, if the frame type is a poll request, then the poll type and polling interval is added to the poll list in step 316. At decision 318, if the frame type is a message frame, then the remote unit 6 has a message for the base station 2. The message frame is processed at step 320, then a response generated at decision 322, step 324 and step 326. This process continues until the link breaks with a time-out at decision 306. The processing of the bit stream which is output by the receiver 34 (see FIG. 3A) in the base station 2 will continuously perform scans of the incoming data to pick out packets with a good cyclic redundancy check code (CRCC). When the transmissions of two or more remote units 6 are transmitted in contention (i.e., a collision) they will be received as overlapping data. As previously discussed, the receiver 34 in the base station 2 will capture the strongest bits at any time to within a 6 db resolution. This is illustrated in FIG. 9 where the receive-bit processing receives the start of the weaker signal from station I, then receives bits of the stronger signal from station J overlaying the remainder of the packet causing the CRCC to fail. In a conventional receiver, the start of the stronger frame would be missed assuming it was data of the first packet. Thus both frames would be lost. The system 30 stores the bit stream in a circular buffer in the memory 40 allowing the processing to back up to one byte past the start of the first frame and then scan for another packet correlation sequence whenever there was a CRCC failure. It will then find the second stronger packet with a good CRCC, and process that reception. Only the weaker bit stream is discarded rather than both. The circular buffer in the memory 40 needs to be large enough I0 to hold at least two packets, and is shifted one bit as each bit is received. The reception capture flow chart of FIG. 10 illustrates the operation of the system 30 to capture a strong RF transmission that interferes with a weaker data packet reception that is already in progress. The normal reception process starts at 400 when software initialization calls the receive driver to begin a search for a transmission from a remote unit 6. The search for reception begins at step 402 by initializing the search for the correlation pattern that is transmitted at the beginning of every data packet from all remote units 6 currently communicating with the particular base station 2. It also clears flags at step 404 that indicate that an embedded pattern has been found and sets a pattern shift count to zero. An embedded pattern is defined as a correlation pattern from the start of a stronger RF signal that has interfered with the initial reception. The loop at step 406 and decision 408 is the actual search for the correlation pattern. As previously discussed, each base station 2 operates with a unique correlation pattern for its region R1 or R2 and will only communicate with remote units 6 transmitting that correlation pattern. The receiver 34 in the base station 2 continually generates a data stream from whatever signal it receives. When no remote units 6 are transmitting, there is no coherent signal and the data stream is just random bits. Thus, the correlation pattern will not be found and the system 30 loops between step 406 and decision 408. When a remote unit 6 does transmit, the receiver 34 in the base station 2 will lock on to the signal and the correlation pattern transmitted will be presented in a serial fashion at the output of the receiver in step 406. As soon as the last data bit of the correlation pattern is received correctly, decision 408 is satisfied and byte synchronization with the incoming data stream is achieved. The next 8 bits are received in step 410 to form a byte. If the pattern shift count is non-zero, the byte is shifted by the specified number of bits. Initially the shift count is set to zero in step 404. The byte is then examined in step 414 to see if it might contain a part of an embedded correlation pattern from any other remote unit 6 having a stronger RF signal. In decision 416 the system 30 determines whether an entire embedded correlation pattern has been found. If an entire embedded correlation pattern has been found, the result of decision 416 is YES and in step 418, the system 30 saves the shift count indicating how many bits "out of byte synchronization" the embedded pattern is and in step 420 flags the location in the receive buffer where the pattern was found. If no embedded correlation pattern was found, the result of decision 416 is NO. In that case, or upon completion of step 420, the system 30 passes the current byte to be processed by the receive task in step 422. If the receive task in step 422 does not indicate that an entire packet has been received, decision 424 is NO and the system 30 returns to step 410 to receive another byte. If the packet reception is complete, the result of decision 424 is YES and in step 426 the system 30 resets the packet reception logic, which enables the base station to receive a new frame from the remote units 6. In decision 428 the system 30 determines whether the data packet reception ended in an error. As discussed above, the system 30 uses the CRCC to detect transmission errors. However, those of ordinary skill in the art will recognize that error detection schemes other than the CRCC can also be used. If the data packet reception did not end in an error, the result of decision 428 is NO and any embedded correlation pattern detected would be coincidental and can be ignored. If the result of decision 428 is NO, the system 30 re-starts the packet reception process at step 402. If the packet reception did end in an error, the result of decision 428 is YES. In that case, the system 30, in decision 430, checks to see if an embedded correlation pattern was found. If no embedded correlation pattern was found, the result of decision 430 is NO, and the system 30 re-starts the packet reception process at step 402. If an embedded correlation pattern was found, the result of decision 430 is YES, indicating that it is possible that the reception was interfered with by a stronger signal and that a good reception from the stronger, interfering unit is in progress. In that case, step 432 sets a pointer to the point in the data buffer 40a (see FIG. 3A) where the embedded correlation pattern was found. The system 30 sets the detected shift offset in step 434 and a new packet reception is immediately initiated by receiving the next byte from the receive buffer at step 410. This new packet is then received and processed normally. The result of this process is that the stronger, interfering remote unit's transmission is not lost, but received and processed as a good reception. The receiving base station 2 can then acknowledge the new reception and the need for the interfering unit to re-transmit its data at a later time is averted. Thus, the overall efficiency of the system 30 is improved because data was not lost from two colliding remote units 6. With extended range RF equipment, the effective size of each cell C1 to C7 surrounding a base station 2 increases and thus increases the number of remote units 6 in a particular cell at any time. Each of the cells C1 to C7 overlaps the surrounding cells to some degree. As previously discussed, typical cellular phone networks use different frequencies in each adjoining cell to reduce contention. This requires each cellular phone to work with several frequencies, increasing cost and complexity of the unit. As shown in FIG. 11, the system 30 allows the use of a single frequency or channel by varying the correlation pattern or synchronization data pattern used the base station 2 in each of the cells C1 to C7. This prevents the receiver 34 in the base station 2 in the region R1 (see FIG. 1) from synchronizing with transmissions from the region R2 that use a different correlation pattern. There will still be a small level of contention, but as long as the cell size is large enough to allow the receiver 34 to capture the nearest remote units 6, as described above, there will be no loss of data packets. It should be noted that each remote unit 6 must support all of the correlation patterns in use within a network so that it can communicate with any base station 2. The variable correlation patterns are used by the system 30 to provide logical isolation of remote units 6 that are widely separated into the regions R1 and R2 (see FIG. 1) in a large network, even when the RF characteristics of the network sometimes would allow communications between the widely separated remote units and base stations 2. By assigning different correlation patterns to the different regions R1 and PC2 of the network and assigning which correlation patterns a remote unit 6 is allowed to detect, remote units can be restricted to communications within their region of the network. However, to allow remote units 6 to roam freely throughout the entire network without the possibility of losing communications with the network or requiring continual manual configuration, overrides are provided which allow a remote unit to communicate in other areas of the network if it is unable to communicate in its assigned area. The system 30 may assign different correlation patterns for the regions R1 and R2 (see FIG. 1) such that base stations 2 within a particular region use the same correlation pattern. This approach provides regional control of the network and prevents the base station 2 in the region R1 from communicating with the remote units 6 in the region R2. Typically, the radio transmissions between the regions R1 and R2 are at a low signal strength because of the distance separating the regions. Thus, the base stations 2 and remote units 6 in the region R1 ignore all transmissions from base stations and remote units in the region R2. The base stations 2 and remote units 6 in the region R1 are free to transmit in the CSMA mode even if they detect a transmission from a base station or remote unit in the region R2 because the base stations and remote units in the region R1 ignore the transmissions from the region R2. Although the system 30 is described herein as using different correlation patterns for the regions R1 and R2, it is possible to assign a different correlation pattern to each of the cells C1 to C7. In the presently preferred embodiment, the correlation pattern transmitted by the remote unit 6 must match the correlation pattern of the base station 2 or the transmission will be ignored. In an alternative embodiment, the CPU 38 (see FIGS. 3A and 3B) can be programmed to detect a correlation between the transmitted correlation pattern and the correlation pattern assigned to the base station 2. If there is sufficient correlation between the transmitted correlation pattern and the correlation pattern assigned to the base station 2, the base station will process the transmission. For example, the correlation pattern, indicated by the reference letter C in FIG. 4, is 24 bits. If 20 bits out of the 24 bit correlation pattern C transmitted by the remote unit match the correlation pattern assigned to the base station 2, the base station will process the transmission. Other correlation levels may be chosen for use with the system 30. The techniques used by the system 30 to communicate using the correlation patterns is described in the flowchart of FIG. 11. At the start 500, the software in the memory 40 (see FIGS. 3A and 3B) initializes the receive process in both the base stations 2 and the remote units 6. The base station 2 uses a fixed correlation pattern while the remote unit 6 has as many as 16 correlation patterns that are defined as valid. Any of the correlation patterns can be enabled or disabled with configuration commands. The search for any defined correlation pattern is done at step 502. When the receiver 34 detects a defined correlation pattern, the system 30, at step 504, stores the time at which the pattern was received to determine the frequency of reception of each correlation pattern. In decision 506, the system 30 tests for whether the received pattern is enabled. If the pattern is disabled, the result of decision 506 is NO, and in decision 508 the system 30 determines whether the pattern disable is in an override state. If the pattern disable is in the override state, the result of decision 508 is YES, and the reception continues at step 514. If the pattern disable is not in the override state, the result of decision 508 is NO, and the system 30, in decision 510, determines whether one of the enabled patterns in the time interval specified in the unit's configuration has been successfully received. If the unit has successfully received an enabled pattern, the disabled pattern reception is rejected and the search for correlation pattern is resumed at step 502. If the unit has not received an enabled pattern recently, the override flag for the correlation pattern received is set at step 512, allowing the unit to communicate outside of its assigned network area by proceeding to step 514. In order to communicate with another unit, this unit must use the correlation pattern that it received from the other unit. The received correlation pattern is posted at step 514 for the transmit process. The reception of the data packet is then continued at step 516. In decision 518, the system 30 determines if the data packet was received error free. If the data packet was not received error free, the result of decision 518 is NO. In that case, the receive process resets to step 502. If the data packet was received error free, the result of decision 518 is YES, and the system 30 determines whether a response transmission is required in decision 520. If no response is required, the result of decision 520 is NO, and the receive process resets to step 502. It should be noted that the response may be immediate in response to an addressed acquire of this unit, time synchronized in response to a poll, or even randomly delayed as a CSMA response. If a response is required, the result of decision 520 is YES and the communications process continues at step 522 using the received correlation pattern. If the communications process is unsuccessful (no acknowledgment received), the result of decision 524 is NO and the system 30 resets the receive process to step 502. If the communications is successful, decision 526 determines whether the process used an enabled or disabled (i.e., using the override) correlation pattern. If the correlation pattern was enabled, the result of decision 526 is YES and the unit is restricted to communications within its assigned network area so any override flags that are set are cleared at step 528. If the correlation pattern was enabled override result of decision 526 is NO and any override flags are left set as the next reception is started by returning flow to step 502. In one example of the system 30, a complicated system of fixed base stations 2 and remote units 6 was installed in British Columbia to allow aircraft of the Forest Protection Branch of the Ministry of Forests to be tracked, and to exchange digital messages. This was done as a part of a resource tracking system. The position of each aircraft was tracked using an on-board GPS receiver 50 (see FIG. 3B) which relays the position data to a RF modem that transmitted the position to the nearest base station 2. Each aircraft was required to deliver its position to the central computer system 8 (see FIG. 2) every 30 seconds. The RF modems used transmit a 1/2 duplex frame at a power of between 100 watts and 150 watts to extend the range between base stations 2 to 200 miles. This minimized the number of base stations 2 required to cover the entire Province of British Columbia. The base stations 2 were installed on mountain tops to extend range of the cells C1 to C7 (see FIG. 1) and regions R1 and R2 as much as possible. The net effect of extending the range of the cells C1 to C7 was also to increase the number of remote units 6 that could transmit in contention with one another. In addition to the increased number of aircraft included in the larger cells C1 to C7, ground based vehicles and ground based work camps also have remote units 6 that transmit to the base station 2. The system 30 allowed the different types of remote units 6 to communicate effectively over the same channel at different polling intervals. For example, the aircraft position changes rapidly and thus requires a shorter polling interval to provide accurate position data. In contrast, a remote unit 6 at a ground based work camp changes location infrequently and thus can use a longer polling period to maintain the same level of accuracy in position data. The remote units 6 can communicate with any base station and can, if necessary, transmit information to another remote unit for relay to the base station if the remote unit is temporarily out of contact with the base station. The remote unit 6 can select any base station 2 with which to communicate and uses two operational modes to transmit data of differing priorities. Thus, the system 30 allows flexibility in communications and greater utilization of the bandwidth than previous communications systems. The unique combination of operational modes allows for low priority data to be sent in a lower priority mode, and high priority data to be sent in the time slot allocated for that unit. The remote units can freely communicate with any base station and provisions are included to prevent reception from unauthorized remote units. It is to be understood that even though various embodiments and advantages of the present invention have been set forth in the foregoing description, the above disclosure is illustrative only, and changes may be made in detail, yet remain within the broad principles of the invention. Therefore, the present invention is to be limited only by the appended claims.

A technique for optimizing throughput on a communications channel shared by multiple users. A communications channel that must be shared by a large number of devices has the potential of being very inefficient because of collisions or overlapping of transmissions by the various devices. The system combines a carrier sense, multiple access (CSMA) mode with a time division multiple access (TDMA) mode to achieve a channel utilization greater than 90 percent. The remote units send a poll request to a base station using the CSMA mode and receive a poll signal from the base station with a poll sequence. The remote units send their data in their assigned time slot. The remote units do not have to all be in radio contact with each other to maintain synchronization. Each remote unit selects the base station that it wishes to communicate with based on signal strength of various base stations. The remote units may switch from one base station to another by addressing the selected base station and using the selected base station's synchronization data pattern in radio transmissions from the remote unit. The synchronization data pattern may be different for each base station or may be identical for groups of base stations to provide broader regional control of the communications network. The base station will only communicate with remote units using the synchronization code for that base station. The system also recovers data from a more powerful signal that collides with a weaker signal by examining the received data for the synchronization code from the more powerful signal.

BACKGROUND OF THE INVENTION The present invention relates to a sieve belt comprised of a multiplicity of helices made of thermosettable synthetic resin material, especially synthetic resin wire, with adjacent helices intermeshed with each other so that the windings of one helix enter between the windings of the adjacent helix and pintle wires which are inserted through the respective channels thus formed by the intermeshed helices. For controlling the air permeability of the sieve belt the hollow interiors of the helices are filled with a filler material. The invention further relates to a method for producing such a sieve belt. Due to varying requirements, it is desirable to be able to change the air permeability of sieve belts made of synthetic resin helices. In the sieve belt disclosed in U.S. patent application Ser. No. 111,497 filed Jan. 11, 1980 now U.S. Pat No. 4,346,138 in the name of Johannes Lefferts and assigned to the same assignee as the present application, the spirals or helices are open and the air permeability is very high. In papermaking machines operating at very high speeds, high air permeability may be disadvantageous since it causes very intense air circulation which may disturb the paper web. The air permeability could be reduced by inserting stiff monofilaments into the interiors of the helices from the sieve belt edges or by inserting spun yarns or multifilament yarns by means of a threading device. However, such inserted material would lie straight in the interiors of the helices so that a large amount of filling material would be required to appreciably reduce the air permeability. Moreover, the large amount of filler material would greatly increase the weight per unit area of the sieve so that the insertion of the filler material and generally the handling of the sieve would become cumbersome, especially in the mounting of the sieve belt on the papermaking machine. The later introduction of filler material into the assembled sieve belt meets with difficulties and brings about disadvantages. Either the filler materials are introduced into the interlocked helices before the sieve belt is thermoset or the filler materials are inserted into and threaded through the channels after thermosetting. In both cases, the sieve belt must be thermoset a second time after insertion of the filler material since otherwise, the filler material might shrink later on under the influence of the papermachine temperature. Two thermosetting steps are very expensive and time consuming. Moreover, when the filler material is introduced prior to thermosetting of the sieve belt, there is the risk that the helices may shift over the pintle wires which are still straight at that stage so that humps and buckles may develop in the sieve belt. Furthermore, in both modes of operation, a certain length of filler material would have to extend laterally from the sieve belt so that after thermosetting and shrinkage of the filler material, the sieve belt will still be filled across its entire width. Such a method would be complicated and susceptible to trouble. Another disadvantage resides in the fact that the filler material extends straight through the helices so that it can easily slip out of the sieve belt. For instances, if the edge of the sieve belt is damaged in the papermaking machine, the filler material can easily get caught on parts of the papermaking machine and will then be pulled out of the sieve belt. This may happen when the sieve belt laterally chafes against the machine. SUMMARY OF THE INVENTION The present invention provides a new and inproved sieve belt having reduced air permeability which can be produced quickly and economically. According to the present invention, the filler material, for example multi-filament or mono-filament yarn, spun yarn or taped yarn, is disposed in the hollow interiors of the helices in a completely untensioned state in a stuffed or crimped condition. Since no tension is exerted on the filler material it expands in a transverse direction thereby filling the hollow interiors of the helices better and more uniformly than a tensioned yarn. Especially with the use of softly twisted multi-filament yarns and spun yarns as filler materials, the individual fibers are uniformly distributed throughout the hollow space so that the sieve belt does not have any open areas. The present invention provides a new and improved method for assembling sieve belts with filler material in that the filler material contained in the hollow interiors of the helices yields as the helices are interlocked and can be easily pushed aside thereby permitting the use of already filled helices for the manufacture of the sieve belt. The channel into which the pintle wire is to be inserted is formed without any particular difficulties. Straight mono-filaments or multi-filaments, when used as filler material, would not make room for the formation of the channel and would offer considerable resistance to interlocking of the helices. If such a filler material were used it could be introduced into the hollow helix interiors only after interlocking of the helices. The aforementioned difficulties resulting from the filling of the helices after they have been interlocked to form the sieve belt are not encountered in the manufacture of the sieve belt according to the present invention. Although minor shrinkage of the filler material may occur on thermosetting of the filled sieve belt, sufficient length of the filler material is available to allow for such shrinkage, that is, after thermosetting of the sieve belt the filler material is still more or less undulated rather than straight in the hollow interior of the helices. This undulation causes sufficient friction in the interior of the helices to prevent slipping of the filler material out of the helices even if the edges should be damaged. This is significant particularly with the use of smooth material, for example mono-filaments, twisted mono-filaments or multi-filaments. Slippage of the filler material out of the helices can also be prevented by forcing the material into the interior of the helices. However, in practice this cannot be realized because the sieve belts would become very heavy and the helices so plugged as to be no longer capable of being interlocked. In principle, there are two possibilities for filling the interiors of the helices before interlocking them, namely, either to wind the synthetic resin wire around the filler material when the helices are formed or to fill the helices with filler material after their formation but prior to interlocking. In the second case, the helices can be filled so that first one or more monofilament wires are threaded into the interior of the helices and thereafter the filler material is deformed under external influences, for example by wrapping the helices with a yarn so that the wraps of the yarn come to lie between the windings of the helices and then tensioning the yarn in a direction normal to the longitudinal axis of the helix. In this manner, the yarn tends to pull the filler material somewhat out between the helix windings normal to the helix axis. In this state, the filler material is thermoset. Another possibility is to deform the filler material from the outside by gears or by impressing other helices. Finally, a yarn composed of a less shrinkable and a highly shrinkable component may be employed. Such a yarn will crimp automatically during thermosetting. The same effect can be obtained with the use of bicomponent filaments. The sieve belt according to the present invention is especially suited for use with a paper machine sieve and is especially advantageous when used in the pressing section of a papermaking machine. The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention as illustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a sieve belt having filled helices showing a comparison between straight filling material and untensioned or crimped filling material. FIG. 2 is a longitudinal sectional view of the two arrangements shown in FIG. 1 comparing the helices filled with a straight tensioned yarn and the helices filled with untensioned filler material thermoset in a wavey configuration. FIG. 3 is a sectional view similar to FIG. 2 showing how the filler material extends beyond the helix arcs when the filler yarn is initially provided with a greater excess length. FIG. 4 is a schematic view showing the apparatus for manufacturing filled helices for a sieve belt according to the present invention. DETAILED DESCRIPTION OF THE INVENTION As described in prior U.S. application Ser. No. 111,497 (supra) the sieve belt is comprised of a plurality of intermeshed helices joined together by a plurality of pintle wires, one in each channel formed by two adjacent helices. As illustrated in FIG. 1 of the present application, the hollow interior of each helix is filled with a filler material. The spaces A and B of the two helices at the left of FIG. 1 are filled with straight mono-filament yarn while the spaces C and D on the right of FIG. 1 are filled with a bulky multi-filament or spun yarn. It is clear that voids are still present in the interior spaces A and B, for example where the helix arcs of adjacent helices intermesh, while the bulky filler material completely fills the interior spaces C and D. From FIG. 2 it may be seen that the filler material on the right not only fills the hollow interiors of the helices but that it also partially enters between the helix arcs. In this manner, the surface of the sieve belt is closed and equalized and the chance of very slight markings caused by the sieve belt is further reduced. Moreover, such a complete filling of the spaces between the helix arcs enlarges the supporting area of the sieve belt which promotes drying of the paper. By providing the filler material with an especially great excess length, it is possible that the filler material will even extend beyond the arcs as seen in FIG. 3. This imparts a soft surface to the sieve belt. An arrangement for producing filled helices is shown in FIG. 4. The portion of the method for producing the helix is similar to that disclosed in prior application Ser. No. 111,497 (supra). The apparatus comprises a rotating mandrel D and a cone K which are guided in a reciprocating manner at one end of the mandrel 20. The helix is produced by feeding a first filament T from a package P to the rapidly rotating mandrel D. The first filament T is thus wound onto the mandrel 20 by means of the cone K which reciprocates rapidly and the thus formed helix is pushed across the mandrel past heating means to the righthand side as viewed in FIG. 4. The arrangement according to the present invention further provides for a filler yarn G which is withdrawn from a package S and passes between rolls W which are adjustable as to speed. The package S and the rolls W are connected to the shaft of the mandrel D so as to rotate as a unit with the mandrel D and the cone K about the longitudinal axis of the mandrel D. Moreover, the package P for the filament T from which the helices are formed is arranged so that the filament T first comes into contact with the cone K at the point P1 in the outer third of the cone K, then passes over the inner part of the cone K and is finally wound about the mandrel D. The filler yarn G contacts the cone K at the periphery thereof and is engaged by the filament T at the point P1, that is, it is clamped between the filament T and the surface of the cone K. As the filament T slides over the inner part of the cone K, it takes along a portion of the filler yarn G disposed between the points P1 and P2. The point P2 is located at the transition between the cone K and the mandrel D, that is, at the point where the winding of the helix starts. By adjusting the speed of the rolls W the length of the piece of filler yarn G which is taken along by the filament T can be controlled and is then placed within the winding of the helix. The filler yarn G is urged laterally outwardly between the windings of the filament T and the auxiliary wire H and is set in this condition by the heating means. The excess length of the filler yarn G is thermoset in this way, that is, the excess length of the filler material is consumed in the crimping of the material. After the auxiliary wire H has left the mandrel D and the helix has been pushed from the mandrel D the thermoset crimps of the filler yarn G slip into the interior of the helix and spread out in the hollow interior of the helix. The extent of crimping of the filler yarn G is determined by the peripheral speed of the rolls W as mentioned before. The extent of crimp generally varies between 1.2 and 8, that is, in a given length of the helix 1.2X to 8X this length of filler yarn is disposed. Lower values for the crimp are also possible. To complete the manufacture of the sieve belt, the filled helices are pushed laterally one into the other so that the windings of one helix come to lie between the windings of the adjacent helix. The helices are pushed into one another to the extent necessary to form a channel into which a pintle wire is inserted for firmly locking the helices together. Finally, the sieve belt is thermoset under tension so that the helices are somewhat buried in the material of the pintle wire thereby causing the pintle wire to assume a wavy configuration. As the helices are thus interlocked, the filler material in one helix is pushed away by the windings of the other helix. Since the filler material is very bulky, it does not offer too much resistance and yields to the pressure. The air permeability of the sieve belt is determined, inter alia, by the type of filler material and the extent of its crimp. Thus, for example, in a sieve belt having a thickness of 2.5 mm and comprised of helices having a wire thickness of 0.7 mm, pintle wire having a wire thickness of 0.9 mm and 20 pintle wires per 10 cm of sieve length, the air permeability is 320 m 3 per m 2 per minute at a pressure differential of 12.7 mm water head. When the same sieve belt is made from helices filled with two textured polyamide multi-filament yarns of 1300 dtex each having a 1.5 crimp, the air permeability drops to 140 m 3 per m 2 per minute. Other types of filler material may be used such as one having a linear textile structure. "Tape yarn" is also usable and is chemical tape (extruded and slit), spliced tape or woven tape. While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those 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.

The sieve belt is comprised of a multiplicity of helices made of thermosettable synthetic resin material which are interlocked with each other by inserting a plurality of pintle wires into the channels defined by the overlapping helices. For controlling the air permeability of the sieve belt, the hollow interiors of the helices are filled with a filler material comprised of crimped synthetic filaments.

BACKGROUND OF THE INVENTION The present invention relates to an improved method for accelerating the freezing of ice, initially formed by the freezing of a sea water spray or impounded sea water, and more particularly to an improved method to form an engineered load-bearing ice structure of high quality and in a shorter time than normally could be obtained. Rapid freezing of sea water is important in certain applications such as the construction of load-bearing ice structures in offshore Arctic regions where such structures are employed in conjunction with hydrocarbon exploration and production and in the construction of airfields, roads, camps and the like. In these applications, sea water is used exclusively as the aqueous medium and construction is usually started as soon as the ambient air temperature is sufficiently low to cause freezing of the sea water. It is economically advantageous to be able to cause the freezing of sea water to proceed as rapidly as possible so that load-bearing structures may be constructed in a relatively short period of time so as to extend to the maximum degree possible the utility of the manufactured structure. A method commonly employed to form ice structures involves the propelling of sea water through the air as essentially a stream of sea water and over significant horizontal distances. The volume of the continuous stream may range up to 30,000 gallons per minute from a single nozzle used to propel the salt water over the needed distance. The air, by virtue of its low temperature with respect to the nominal freezing temperature of sea water (-1.6 to -2.0 degrees C depending on salinity), acts as a coolant. The formation of droplets and the interaction of the sea water stream/droplet spray with cooler air results in freezing of the projected droplet spray. The efficiency of freezing depends on efficient heat exchange between the sprayed droplets and air. Formation of water droplets and the size of the droplets ultimately governs freezing efficiency at any ambient air temperature less than the nominal freezing temperature of the sea water. At the spray nozzle, the bulk of the sea water is in the form of a solid stream of water having high momentum in order to cover the desired relatively large horizontal distance. In the vicinity of the nozzle, shear and turbulent forces along the periphery of the water stream initiate droplet breakup and segregation. Along the trajectory of the stream/droplet spray, wind forces and gravitational forces promote increasing droplet breakup and segregation. Maximum droplet breakup, in the absence of significant wind forces, occurs at the apogee of the stream trajectory. The surface tension of the sea water is the fundamental property which governs how soon discrete water droplets will form and their size distribution for any imposed set of ambient conditions. Load-bearing ice structures are also commonly built by forming a berm or dike and then flooding the impounded area with sea water, the process being repeated, after freezing of the sea water, as necessary until a desired thickness of ice has formed. Ice structures which are used as the support unit for large drill rigs are themselves large. Construction may require one or more months. It is necessary, therefore, to accelerate the ice construction phase so as to allow maximum time for drilling activities prior to the onset of the Spring thaw. The more or less routine application of flooding-spraying technology in conjunction with offshore Arctic application is described in the prior art, U.S. Pat. No. 4,048,808 being a typical example. In accordance with this invention, it has been discovered that the governing property of a high volume sea water stream is formation of water droplets varying in a size from 1 to about 3 mm in diameter. These droplets freeze in the form of hailstones, which are rounded or spherical masses of ice. The interior of the frozen droplets commonly contain liquid water of high salinity consistent with finite freezing rates and thermodynamic constraints that govern the freezing of saline solutions which have a true eutectic. Successful ice construction requires that the projected sprayed material which falls to the surface have a liquid content. Some droplets crush on impact releasing additional brine. The fallen material undergoes partial melting and then refreezing. Excess brine drains either away from the structure by virtue of its reduced freezing temperature, caused by partial evaporation during flight and by salt rejection that occurs simultaneously with freezing or remains entrained in the porosity of the spray ice. On impact with the ground, the brine is released and there is some partial melting of the frozen material. The newly formed slush then refreezes upon exposure to ambient temperature air. The refreezing which occurs after impact is the phenomena that is responsible for strength development in sprayed ice. In ice construction, where the aim is to build a substantial load-bearing structure of a relatively large dimension, dry snow is undesirable and detrimental because snow contributes to a general weakening of the manufactured structure and snow does not possess the substantial strength of ice. Sea water spray construction of ice islands is a complex process that includes several important phenomena which collectively control the properties of the manufactured structure. Sea water is usually applied as a spray. The freezing of the spray is controlled by ambient climactic conditions, the volume of spray and the size distribution of water droplets within the spray. Spray ice, which consists of a mixture of ice and brine and/or precipitated salt may, depending upon ambient temperature and wind conditions, partially remelt upon impact and then slowly refreeze. Typically, spray ice construction is a cyclic process where sea water is sprayed for a period of time and then spraying is terminated to allow refreezing of the sprayed surface. The cycle is then repeated as necessary to produce the desired structure. Internal structure of spray ice reflects the cyclic nature of its formation. Manufactured ice consists of alternating layers of relatively hard ice immediately underlain by a much thicker layer of much softer material. The internal structure of an ice island is a direct reflection of the techniques used for its construction. The basic methodology for construction of an ice island using sea water spraying techniques, consists of freezing a sea water spray by the cooling action of ambient temperature air on the spray. Since sea water must be sprayed in large volumes over considerable horizontal distances, nozzles are selected primarily for their throwing or spraying distance. This requirement places rather stringent controls of the size of water droplets which form in the spray. It is the discrete water droplets which ultimately freeze and fall to the ground. As droplets form in the spray, they freeze in the form of spherical hailstones consisting of ice. The cores of many of the larger hailstones contain brine significantly more saline than the source sea water due to partial evaporation of sprayed sea water and salt rejection during the freezing process. Upon impact, some hailstones shatter releasing brine. Depending upon ambient temperatures, some free, unfrozen brine may also reach the ground unfrozen but concentrated by partial evaporation. The spray may reach heights above ground surface of two hundred (200) feet or more. Air temperature differences between the maximum height attained by the spray and ground level can also encourage partial remelting of spray ice. The saline brine contacts previously sprayed and frozen material and causes partial melting of this material. The residue brine as a consequence of the partial remelting decreases in salinity. The newly formed slush is then slowly refrozen by the action of the ambient air. The slush refreezes from its surface downward. As the initial upper surface refreezes, lower levels of the slush are insulated from direct air contact and they freeze at a lower rate. As a result of this process, the sprayed ice consists of cyclic deposits of hard ice immediately underlain by softer material that was prevented from fully freezing. If spraying is stopped and then resumed at a later time, the newly fallen material will cause partial remelting of the previously frozen surface. Thus, the thickness of the hard ice surface is probably never as great as it was when originally formed just before resumption of spraying. A thermal gradient exists from the sea water-ice interface to the ice-air interface. Thermistor arrays are usually buried in an ice island during construction, and temperature data derived from these devices graphically demonstrate the heat transfer phenomena. Thus, partial remelting of newly formed spray ice is also a reflection of heat transfer from the warmer sea water to the colder free ice surface. The primary factors that govern spray ice construction can be summarized as follows: (1) the freezing dynamics of a sea water spray, and (2) the refreezing of spray ice. In the past, researches have concentrated on understanding spray freezing phenomena. Essentially, no attention has been devoted to the problem of spray ice refreezing. The dominating importance of spray ice refreezing can be readily understood when it is noted that during a typical twenty four (24) hour period, sea water may be sprayed for ten (10) hours or less whereas the remainder of the twenty four (24) hour period is spent waiting for spray ice to refreeze. Any improvement resulting in a diminution of the time required to refreeze spray ice may have dramatic and significant impact on overall construction time and cost. The time required to refreeze spray ice after a spraying period is the major factor that influences the time required to build an ice structure. It would be desirable, therefore, to provide improved and relatively simple methods for accelerating spray ice refreezing. SUMMARY OF THE PRESENT INVENTION In brief, the present invention focuses on acceleration of the formation of load bearing ice structures and more particularly to the acceleration of the refreezing of ice structures during their construction. In one form, the method of this invention involves use of a conveyance to move a ventilation fan across the newly deposited ice surface. Normally, refreezing of spray ice occurs by ambient air cooling. Wind blows cool air horizontally across the ice surface. However, the efficiency of the process is limited by thermal effects which retard heat heat transfer when the ice surface initially refreezes thereby insulating lower lying material from the direct cooling effects of ambient temperature air. Furthermore, wind velocity in the boundary layer adjacent to the ice surface may be a small fraction of wind forces at higher levels above the ice surface. The method of the present invention involves forced refreezing by directing a vertical column of air downward on the ice surface with sufficient force to disrupt the surface material and, thereby, to cause cooling to a greater depth than would be otherwise possible. The roughened air-blown surface may then be resmoothed by a rake attached to the ventilation fan conveyance. Another approach involves mounting the fan directly on self-contained power units. Other methods for direction of air columns downward in a spray ice surface include use of helicopters of hydrofoils operated over the desired area or tracked vehicles or use of winches and cranes to support or transport any one of a number of different well known devices to move a vertical air column across the spray ice surface. Ice construction using flooding techniques is effective and routinely practiced in Arctic regions because it is possible to freeze a shallow impounded mass of sea water. Cooling occurs at the water-air interface. An intrinsic property of water is the attainment of maximum density at a temperature slightly above its freezing temperature. This property allows for more uniform cooling of a large impounded water mass. The forced refreezing method can, therefore, equally be applied to the accelerated freezing of impounded sea water. Application of the forced refreezing method, whether applied to the refreezing of spray ice or to the accelerated freezing of impounded sea water, will significantly improve the mechanical properties of the ice structure, where improvemnt in load-bearing strength and shear resistance is desirable. This improvement is obtained because refreezing of spray ice or accelerated freezing of impounded sea water, occurs over a greater depth range, by virtue of the forced refreezing of the downward directed air column which contacts the spray ice or impounded sea water over a greater vertical depth than could be obtained normally by the action of wind blowing more or less horizontal with respect to the local ground surface. In accordance with the present invention, enhanced cooling or forced refreezing of spray ice or forced freezing of impounded sea water can be accomplished by use of a large downward-facing fan that is moved over the freshly sprayed or flooded surface to decrease the heat transfer resistance between the ambient temperature and surface temperature. There are two important factors that work together to increase the freezing speed considerably. These two factors are that the heat transfer coefficient is much greater in stagnation flow, compared to parallel flow; and, in a related aspect, the blowing arrangement ensures that the cold far-field temperature is brought in closer proximity of the surface. Virtually any technique for moving fan, or other source of downwardly directed frigid air, across a surface may be employed. By the present invention, it is the movement of large volumes of cold ambient temperature air downward against a layer of freshly prepared spray ice or impounded sea water which is important and for the purpose of more quickly and completely freezing or refreezing the surface material. The air stream produced by the fan can be controlled so that spray ice or impounded sea water may be cooled over a greater depth than is possible by natural cooling due to wind movement horizontally across the spray ice or impounded sea water surface. This more efficient cooling will lead to more complete freezing and refreezing and, thereby, production of a stronger structure in a shorter time. In Arctic regions, it is common practice to employ wheeled and tracked vehicles in conjunction with ice island and other types of construction activities. Modification of these devices by addition of the ventilation fan is practical, feasible, and by means disclosed herein, beneficial in providing for more rapid and complete freezing and refreezing of spray ice and impounded sea water. Application of the methods disclosed herein will, therefore, significantly shorten the time normally required to fabricate an ice structure and, therefore, reduce construction costs. Furthermore, application of the disclosed methods will result in ice structures having greater inherent load-bearing capacity and resistance to shear, by virtue of more complete freezing, than could otherwise be reasonably expected by application of what is generally recognized to be standard and accepted ice structure construction practice. An obvious implication of the forced refreezing method is its extension to ice construction involving primarily the preparation of offshore ice roads, camps, air fields, parking ramps and the like. It is apparent from the foregoing brief description that the present invention offers many advantages over the prior art methodology. These and other advantages and other objects are made more clearly apparent from a consideration of the several forms in which the present invention may be practiced. Such forms are described and forms of the various apparatus which may be used in the practice of this invention are illustrated in the present specification. The forms described in detail are for the purpose of illustrating the general principles of the present invention; but it is to be understood that such detailed description is not to be taken in a limiting sense. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view of one form of apparatus which may be used to practice the present invention; FIG. 1a is a diagrammatic view, in section, of the device illustrated in FIG. 1; FIG. 2 is a diagrammatic view of another form of apparatus which may be used in the practice of the present invention; FIG. 2a is a diagrammatic view, in section, of the device illustrated in FIG. 2; FIG. 3 is a diagrammatic view of yet another form of apparatus which may be used in the practice of this invention; and FIG. 3a is a diagrammatic view, in section, of the device illustrated in FIG. 3. DETAILED DESCRIPTION OF THE INVENTION In accordance with the present invention, load-bearing ice structures may be fabricated from frozen sea water and in those geographic areas and at those times of the year in which the ambient air temperature is below about minus one degree C. The fabrication of ice structures, in accordance with the present invention, also contemplates the continued maintenance of a site in those regions amenable to construction of ice structures. Thus, for example, roads or aircraft runways and the like may be partially completed by conventional construction and completed or processed in accordance with the present invention. There are two basic modes of practicing the improved ice construction methodology of the present invention. In one mode, a spraying technique, as described, may be used. In the other a berm is formed to impound sea water and thereafter the construction proceeds in accordance with this invention. Ice construction applications involving the freezing of sea water sprays benefit from a reduction in the time required to refreeze partially melted spray ice. In similar fashion, more rapid freezing of impounded sea water would be desirable and beneficial. Accelerated rates of freezing of spray ice and impounded sea water can be obtained by directing a controlled column of frigid ambient air vertically downward against the surface to be frozen. The air temperature should be at least below about minus one degree C. in order to effect freezing of sea water. As mentioned, in the use of spraying techniques, the spraying operation, in addition to providing for the formation of ice particles, by the freezing of water drops, results in the formation of a slush ice which is of a salinity greater than the normal salinity of sea water. The slush ice is, in effect, a residue having a salinity somewhat higher than that of the sea water initially frozen from the droplet spray. As noted, the refreezing of this slush ice is responsible for the development of strength in the formation spray formed ice structures. In the case of spay ice construction, it is this refreezing which adds to the time of construction and which is needed in order to develop the desired strength of the load-bearing ice structure. By the present invention, an initial ice structure is formed. For the purposes of this invention, the initial ice structure is that initially formed at the start of the construction and which, in effect, forms the base upon which the final ice structure is constructed. Overall, the process is cyclical, involving spraying, freezing and refreezing, and spraying etc., a cycle that is repeated until the structure is completed. By the present invention, the freezing and refreezing portion of the cycle is shortened and the nature of the frozen product, in terms of its load carrying qualities, is improved over prior practices. To effect this improvement, it is necessary to effect reasonably rapid freezing of the slush ice or impounded ice, in order to achieve a depth of frozen ice which enhances the loadcarrying ability of the finished ice structure. By the present invention, this is accomplished by the formation of an initial ice structure, either by spraying or impounding procedures, followed by directing downwardly towards the surface of the initial ice structure a controlled column of frigid ambient air. Since the surface of the initial ice structure possesses sufficient integrity to support weight, vehicles may be used to transport equipment intended to generate a downwardly vertically directed column of air. Thus, the methodology involves traversing the initial ice structure while directing the column of air against the surface of the ice structure. in general the entire surface of the initial ice structure is traversed, although this may not be necessary for those portions intended not to be significant load-bearing regions of the completed ice structure. After the first pass, additional sea water is sprayed or added to the impounded area and the process is repeated. In those instances in which the surface of the initial ice structure is such that it is undesirable to use ground vehicles, a helicopter may be used in which case the main rotor down wash forms the controlled column of air which is directed against the ice surface. As an example of the type of vehicles which may be used, reference to the drawings, FIGS. 1 through 3, which illustrate typical land vehicles of the type used in the Arctic region. As illustrated in FIGS. 1 and 1a, a ventilation fan 10 and its associated speed control and electric power generator 12 are mounted on a wheeled platform 15 that is towed behind a wheeled primary power unit 20. The power unit 20 may, for example be a unit known commercially as a ROLL-E-GONE power unit. The air rate is adjusted so as to disturb the spray ice surface with air penetration into the spray ice or, alternatively, into a layer of impounded sea water. Disruption and dispersion of spray ice is minimized by placement of a shroud 25 about the fan which also serves to channel the column of frigid air downwardly. Disrupted and refrozen spray ice may be converted to a smooth surface by passage of the rake 30 located at the end of the fan platform 15. In use, the vehicle traverses the initial ice structure while the fan blows a column of frigid air downwardly towards the surface. One pass is usually sufficient, depending upon the capacity of the fan and the rate of travel. If necessary a partial or added pass may be made, as needed. Thereafter, spraying is continued or additional sea water is added to the impounded area formed by the berm. Alternatively, the fan conveyance of FIGS. 2 and 2a may be employed, in which cases, the various components, such as the fan 50 and the generator 52 are mounted on the bed 55 which is combined into a single power unit. The shroud 65 is located as illustrated, with the rake 66 mounted on the end of the bed. The unit illustrated in FIGS. 3 and 3a is similar to that of FIGS. 2 and 2a except that the vehicle is a tracked vehicle 75, as shown. In use, a layer of spray ice of six (6) to twelve (12) inches thickness is formed. Sea water spraying would then cease for the period required to freeze the deposited material by passage of the fan. Sea water spraying or flooding would then resume and the cycle of spraying or flooding followed by forced refreezing would continue as necessary until an ice structure of desired size were built. It will be apparent from the above detailed disclosure that various modifications may be made, based on the above detailed disclosure, and it is understood that such modifications as will be apparent to those skilled in the art are to be considered within the scope of the present invention as set forth in the appended claims. So, for example, the passage of a helicopter over an impounded body of sea water would be but another instance of the application of the present invention. Similarly, the passage of a hydrofoil or hovercraft, which is a vehicle that moves on a cushion of air, over a spray ice surface or a body of impounded sea water, can be seen to be but another embodiment of the forced refreezing method.

A method for accelerating construction of a load bearing ice island, formed by either sea water spraying or flooding techniques, of higher quality or in a shorter time or both than would otherwise be possible. The method involves forced refreezing of spray ice by application of a vertical stream of cold ambient air, as produced by a fan or other devices described, directly downward on the ice surface or by application of the downwardly directed air stream to an impounded mass of sea water. The specific application for the process is construction of improved load bearing structures as used in Arctic regions in support of offshore hydrocarbon exploration and production activities.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a welding auxiliary material for welding refractory metal parts of high-intensity electric light sources. 2. Description of the Prior Art When manufacturing halogen lamps, the joints between the refractory metal parts such as tungsten or molybdenum are welded joints, as the reliability of the joints is an indispensable requirement. Refractory metal parts of low-wattage halogen lamps with "standard", i.e. not long or extended life, are welded directly together, if no special requirement exists. This, however, does not ensure a satisfactory joint in every case. The Hungarian Patent No. 185.198 discloses a molybdenum lead-in foil for elimination of unsatisfactory features. The surface of the foil is provided with a thin electroplated rhenium layer. Such a lead-in foil has better weldability properties than the simple uncoated foil. A foil prepared in that way is useful in the manufacture of halogen lamps with low current loads and "standard" lives, for joining refractory metal parts and meets the requirements for reliable operation on that field, but not in the case of halogen lamps with extended or long lives and heavy current loads. This is explained by the fact that only a low-thickness rhenium layer can be applied to the surface of the lead-in foil. This has the consequence that, during the welding operation, the lead-in wire is unable to get embedded into the thin rhenium layer applied to the lead-in foil and therefore, a small-surface weld will be produced. In case of high-wattage halogen lamps, the current flow - due to the high current density-generates a substantial amount of thermal load resulting in the earlier destruction of the joint and in shortened lamp life. The functionability of halogen lamps with high current loads and lives of several thousand hours can only be insured if higher requirements for joining the refractory metal parts and for the bond produced in welding are met. In some types of lamps with high current loads as well as long lives, a separate platinum welding auxiliary is placed between the basic metal foil and the current lead-in order to produce a welded joint of satisfactory quality. In this case, platinum will melt during welding and form a molybdenum-platinum alloy phase with a portion of the molybdenum material of the foil. This adversely affects the strength at high temperatures of the molybdenum foil which can result in thickness decrease, cracks and tear in the foil. Another disadvantage is that after melting at the temperature necessary for pinch-sealing the lamp liquid and/or vapour phase platinum can enter the inner space of the lamp where, on reaching the tungsten filament, a lower-melting platinum-tungsten alloy will be formed. This has the possible consequences of local filament fusing and arcing that result in early lamp failure. It should also be considered a disadvantage that the melt creeps on the current lead-in during welding with the consequence that no gas-tight seal will be achieved in some cases. A further disadvantage is that the so-called "brazed joint" will in lamp operation, caused by the local thermal load, get alloyed gradually into the basic metals during the time of operation. Caused by this "loss" of the initial bond, the cross-section available for current conduction will decrease and the local thermal load will be enchanced resulting in a further "loss" and a rapid deterioration of the joint. It is also a common practice to use a platinum coated welding auxiliary material for welding refractory metal parts together. This method suffers from the disadvantages described earlier in the discussion of platinum welding auxiliary material. According to the U.S. Pat. No. 4,823,048, a joint is produced by spot-welding the inner current lead-in and the metal foil together and a welding auxiliary material foil is connected, also by means of welding, to this joint. The filler foil increases the surface area available for current conduction thereby reduces current density. One end of the metal foil is connected to the large-surface portion of the metal foil opposite to the inner current lead-in and its other end, to the inner current lead-in. The joint according to U.S. Pat. No. 4,823,048 has the disadvantages of being complicated to produce and also the inability to solve the problems described earlier related to the cross-section reduction or tear of the current lead-in foil. OBJECTS AND SUMMARY OF THE INVENTION The object of the present invention is therefore to provide welding auxiliary material enabling to join the inner and outer current lead-in of high-wattage electric light sources with the current lead-in foil in a simple and rapid and reliable manner, without damage to the parts during welding and the subsequent pinch-sealing process. Another object is to provide reliability for the joint even in the case of heavy current conduction properties over the time of operation. Other objects and advantages of the present invention will become apparent from the description and drawings which will follow. It has been found that a welding auxiliary material of unique structure and suitable thickness can be prepared by sintering refractory metal powder. Accordingly, the welding auxiliary material for producing welded joints between the refractory metal parts of high-wattage electric light sources is formed with a porous-structure surface layer sintered from a refractory metal powder having a melting point of above 2000° C. The welding auxiliary material according to the invention can be further characterized by that the material of the refractory metal powder is molybdenum and/or rhenium. In a preferred embodiment, the surface layer is sintered on a refractory metal substrate which substrate is a molybdenum foil. In another embodiment, the surface layer pores are impregnated with and additive that promotes welding. In a preferred embodiment, ethanol or other alcohol derivative is used for the additive. The welding auxiliary material has several favourable properties. Due to the porous-structure surface layer, the outer surface of the welding auxiliary material is rough including the side facing the molybdenum current lead-in foil. During the welding operation, the relatively rough surface will make many point-like contacts with a high contact resistance and, caused by the intensive local heat generation, the welding auxiliary material will melt producing microweld spots and resulting in a large-surface welded zone. Due to the intensive local heat generation, the time needed for welding can be shortened and this has the consequence that no recrystallization process will occur in the parts preventing the current lead-in parts from becoming brittle. It should also be considered an advantage that the method of sintering, according to this invention forms a thicker surface layer and the current lead-ins will get embedded deeper into this thicker surface layer which increases the cross-section available for conduction. The increased cross-section results in improved current conduction properties and lower specific heat load and this leads to the prolongation of life. It is also a significant advantage of the present invention that--due to the thicker surface layer--the material surrounding the weld neither will become overly thin nor will be distorted since the welding auxiliary material is thick enough to have satisfactory amount of material for producing the joint. The strength properties at high temperatures of the rhenium-molybdenum and rhenium-tungsten alloys formed by welding when the rhenium-containing welding auxiliary material is used are more favourable than those of the component metals and these alloys melt high above the temperature used during the pinch-sealing process. Due to this fact, the undesired effects which are unavoidable when a platinium metal sheet is used, will not occur. When the welding auxiliary material according to the invention is used, the alloy phase does not creep on the current lead-ins and does not melt during pinch-sealing. This results in a gas-tight seal that can be produced more safely than in the case of other known methods. A further advantage of the welding auxiliary material according to the invention is that the pores can be filled with an additive promoting the welding process and, due to this, the welding auxiliary material is able by itself to provide a protective atmosphere during welding. This solution not only improves the quality of the welded joint, but also reduces the expenses for the welding operation by making unnecessary some machine accessories that have been indispensable so far. BRIEF DESCRIPTION OF THE DRAWINGS In the following, a more detailed description of the invention will be given by means of examples illustrated by drawing figures. In the drawings: FIG. 1 is a perspective view of a preferred embodiment of the welding auxiliary material according to the invention, FIG. 2 is the cross-section of another preferred embodiment, FIG. 3 is a view, partly in section, of the welded joint produced using the welding auxiliary material and FIG. 4 is the sectional view taken along IV--IV of FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, an embodiment of the welding auxiliary material is shown, the entire cross-section of which is prepared from molybdenum metal powder using sintering. The welding auxiliary material 1, also including its surface layer 1a has a porous structure and consists of molybdenum grains ground to grain sizes below 10 microns. Thickness "v" of the welding auxiliary material 1 is 50 microns in this example, but it may vary depending on the field of application. In FIG. 2, the cross-section of an embodiment is seen in which the surface layer 1a of the welding auxiliary material 1 is sintered on the refractory, preferably molybdenum metal substrate 2 having a sheet thickness "s" of 20 microns. Use of the metal substrate 2 is recommended in order to facilitate the handling of the welding auxiliary material 1. Thickness "v" of the welding auxiliary material 1 is 60 microns in this embodiment from which one can calculate that the construction thickness "h" is preferable in respect of producing the welded joint, but the construction thickness "h" of the surface layer 1a may vary from 10 microns up to 50 microns. The pores of the surface layer 1a of the welding auxiliary material 1 are filled with an additive 3 preferably consisting of ethanol, but other alcohol derivatives can also be used. The additive 3, evaporating by the heat generated during welding, forms a protective atmosphere further improving the quality of the weld. In another embodiment, the surface layer 1a is prepared from the mixture of rhenium and molybdenum metal powders instead of molybdenum powder alone. The proportion of rhenium to molybdenum may range between rather different values as the properties of the joint produced are improved by a welding auxiliary material 1 with as low as 5 to 10% rhenium content. To show an example, the preparation of the welding auxiliary material 1 is performed as follows. The molybdenum foil metal substrate 2 having a sheet thickness "s" of 20 microns is coated with a mixture of rhenium and molybdenum metal powders ground to 1 micron grain size and suspended in alcohol. The proportion of rhenium to molybdenum is 2:1 in the mixture. This is followed by the sintering process performed in hydrogen-flushed tungsten-tube furnace at 2200° C. for 5 minutes. After this, the welding auxiliary material 1 described above and having the surface layer 1a with porous structure is prepared. FIGS. 3 and 4 show an example for the use of the welding auxiliary material 1. Current lead-in foil 8 and outer current lead-in wires 7 and 7' welded to it as well as inner current lead-in 6 are placed in pinch-sealed portion 5 of bulb 4. The welding auxiliary material 1 being between the current lead-in foil 8 and the inner current lead-in 6 as well as between the current lead-in wires 7 and 7' and the current lead-in foil 8 is found only in the environment of the welded spot. The current lead-in foil 8 is made of molybdenum and the material of the inner current lead-in 6 is tungsten or molybdenum known and commonly used in light source manufacture. It is seen clearly in FIG. 4 how the inner current lead-in 6 is connected to the current lead-in foil 8 fixed in the pinch-sealed portion 5. The surface layer la molten caused by the effect of heat during welding surrounds the inner current lead-in 6 over a large surface and, due to this, the joint provides better conditions for current conduction than the known solutions do. The welding auxiliary material 1 can be successfully used for welding together the parts located in pinch-sealed portions of electric light sources. Due to its favourable properties such as the resistance to reactive environments, it can also be used for joining parts inside the bulb of mercury and metal halide lamps. Although only preferred embodiments are specifically illustrated and described herein, it will be appreciated that many modifications and variations of the present invention are possible in light of the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.

An improved welding auxiliary material for producing welded joints between refractory metal parts of high-wattage electric light sources is described. The characteristic feature of the invention is that the welding auxiliary material has a porous structure surface layer sintered from a refractory metal powder having a melting point of above 2000° C.

FIELD OF INVENTION [0001] Generally, embodiments of the invention relate to integrated electronics and integrated electronics systems. More specifically, embodiments of the invention relate to a technique and corresponding infrastructure to maintain order of events corresponding to operations for caching agents operating according to a caching protocol where the caching agents are separated from the protocol agents. BACKGROUND [0002] Computer systems and processor architectures, in particular, can use various types communication networks and protocols to exchange information between agents, such as electronic devices, within those systems and architectures. Multiple processing elements (“processing cores”) in a microprocessor, for example, use caching agents to store, retrieve, and exchange data between the various cores of the microprocessor. Likewise, computer systems in which single or multiple core microprocessors are interconnected may use caching agents to store, retrieve and exchange data between the microprocessors or other agents. [0003] In electronic networks, cached data is managed and exchanged according to certain rules, or “protocol,” such that coherency is maintained among the various caches and the devices, such as processing cores, that use the cached data. Caching activity across these devices directly serviced by the caches, such as lookup operations, store operations, invalidation operations, and data transfer operations, can be managed by logic or software routine (collectively or individually referred to as a “cache agent”), such that cache coherency is maintained among the various caches and cache agents. Caching activity within or outside of a microprocessor, such as snoop resolution, write-backs, fills, requests, and conflict resolution, can be managed by logic or software routine (collectively or individually referred to as a “protocol agent”), such that coherency is maintained among the various cache agents and processing cores within the microprocessor and among agents external to the microprocessor. In some prior art multi-core or single-core processors, for example, the caching agent is coupled to a specific coherence protocol agent, which may be physically integrated within the caching agent to which it corresponds. This means that the same circuit and/or software routine may be responsible for implementing cache operations, such as requests, dirty block replacement, fills, reads, etc., as the protocol for managing these operations. [0004] FIG. 1 illustrates a prior art microprocessor having a number of caching agents, each having circuitry to implement the caching protocol used among the caching agents of the microprocessor. In the prior art processor of FIG. 1 , each caching agent is responsible for implementing and keeping track of the cache protocol as applied to itself. That is, each cache agent is coupled to a protocol agent, such that the same unit is responsible for both cache operations and the coherence protocol. Unfortunately, this “decentralized” caching protocol architecture requires redundant use of protocol logic and/or software to maintain the caching protocol among all caching agents within the processor or computer system to which the protocol corresponds. In the case of the protocol being implemented using complementary metal-oxide-semiconductor (CMOS) logic devices, this can result in substantial power consumption by the processor or system, especially in multi-core processors having a number of caching agents. [0005] Furthermore, the prior art caching architecture of FIG. 1 may be somewhat bandwidth limited in the amount of caching traffic supported among the caching agents, as each caching agent has to share the same bus, cache agent ports, and cache agent queuing structure that facilitate communication among the various caching agents. BRIEF DESCRIPTION OF THE DRAWINGS [0006] Claimed subject matter is particularly and distinctly pointed out in the concluding portion of the specification. The claimed subject matter, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which: [0007] FIG. 1 illustrates a prior art caching architecture used within a microprocessor or computer system. [0008] FIG. 2 illustrates a caching architecture according to one embodiment of the invention. [0009] FIG. 3 illustrates a caching architecture including routing circuits according to one embodiment of the invention. [0010] FIG. 4 illustrates a block diagram of one embodiment of message ordering logic to accommodate the various message types while ensuring proper ordering. [0011] FIG. 5 illustrates a computer system having a shared bus architecture, in which one embodiment of the invention may be used. [0012] FIG. 6 illustrates a computer system having a point-to-point bus architecture, in which one embodiment of the invention may be used. DETAILED DESCRIPTION [0013] Embodiments of the invention disclosed herein describe a caching architecture that may be used in an electronic device, such as a single core or multiple core microprocessor, or an electronics system, such a shared bus computer system or a point-to-point (P2P) bus computer system. More particularly, one embodiment of the invention includes a caching architecture, in which the caching protocol is more centralized and decoupled from the caching agents to which the protocol corresponds than in some prior art caching architectures. [0014] With cache agents and protocol agents being detached, a pre-coherence channel is used to ensure that the protocol agent is kept current with the coherence information from the cache agents. In one embodiment, the pre-coherence channel includes an on-chip, or local, interconnection network. In this manner, cache events may have their order maintained and the protocol agents have a view of the coherence of the cache(s) in the system. [0015] In one embodiment, a cache agent can communicate with a protocol agent using two signals that operate in part of the pre-coherence channel: one signal (“AD”) to communicate addressed caching operations, such as data and/or cache ownership requests, data write-back operations, and snoop responses with data for cache-to-cache transfers, from a cache agent, and one signal (“AK”) to communicate non-address responses, such as cache fill acknowledgements and non-data snoop responses, such as a cache “hit” or “miss” indication. Furthermore, in at least one embodiment, each signal may transmit information in opposite directions within the same clock cycle. For example, AK may transmit a first operation, such as a request operation, to a first protocol agent during a first clock cycle in a first direction while transmitting a second operation, such as a write-back operation, to the first or a second protocol agent in the opposite direction during the same clock signal. [0016] The concurrent bidirectional characteristics of the signals, AD and AK, can be conceptualized by two sets of cache agents, routing circuits, and a protocol agent interconnected by two signals, or “rings,” transmitting an AK and AD signal, respectively, in one direction. FIG. 2 , for example, illustrates one embodiment of a caching architecture, in which the two signals, AD and AK, are conceptualized as four rings, two of which are capable of transmitting information in a clockwise direction and two of which are capable of transmitting information in a counter clockwise direction. In particular, the caching architecture 200 of FIG. 2 depicts a first set of caching agents 201 , 203 , 205 , and 207 that correspond to a first caching protocol agent (“protocol agent”) 209 and a second set of caching agents 202 , 204 , 206 , and 208 that correspond to a second protocol agent 210 . Note that in alternative embodiments, only single separate rings are used for the AK and AD signals. In yet another embodiment, more than two rings are used for each of the AK and AD signals. [0017] Each cache agent of the first set can communicate cache operations such as loads and stores to processing cores (not shown in FIG. 2 ), and data requests, data write-back operations, cache fill acknowledgements, and snoop response transactions, to the first protocol agent. Likewise, each cache agent of the second set communicates these non-data cache transactions to the second protocol agent. The cache agents may communicate to the protocol agents, in one embodiment, through a series of router circuit (not shown in FIG. 2 ). [0018] The first and second protocol agents are responsible for arbitrating between the various operations from their respective cache agents such that the operations are managed and completed in a manner consistent with the caching protocol of the caching architecture. [0019] In one embodiment, each cache agent has access to four communication channels (depicted by rings in FIG. 2 ) 211 , 212 , 213 , 214 , upon which caching transactions may be communicated. Each cache agent may communicate cache transactions on any of the four rings illustrated in FIG. 2 . In other embodiments, each cache agent may be restricted to a particular ring or group of rings upon which caching transactions may be communicated to/from the cache agent. The cache data that results from the transactions communicated on the rings of FIG. 2 may be communicated among the cache agents on other communication channels (e.g., data bus) not depicted in FIG. 2 . Alternatively, in some embodiments the cache data may be communicated on the rings depicted in FIG. 2 . Moreover, in other embodiments, each network in FIG. 2 may be configured in other topologies, such as tree topology or a chain. [0020] In the embodiment illustrated in FIG. 2 , caching transactions, such as data and/or cache ownership requests, data write-back operations, and snoop responses with data are sent on rings 212 and 214 (“address” rings) and transactions, such as cache fill acknowledgements and non-data snoop responses, such as a cache “hit” or “miss” indication, are transmitted on rings 211 and 213 (“non-address” rings). In other embodiments, the above or other transactional information may be transmitted on other combinations of the rings 211 - 214 . The particular ring assignment for the various cache transactions discussed above and illustrated in FIG. 2 are only one example of the transactions and ring assignments that may be used in embodiments of the invention. [0021] As each set of cache agents communicates information between each other via the protocol agents, an ordering of the information entering the protocol agent can be maintained, in at least one embodiment, such that the correct information will allow correct coherence protocol transitions in the protocol agent at the correct time. In one embodiment, the ordering of information within the networks is maintained by each protocol agent. More specifically, in one embodiment, each protocol agent maintains the correct ordering of the various caching operations being performed by temporarily storing the operations as they arrive within each protocol agent and retrieving them in the order in which they arrived in order to produce correct coherence protocol transitions in the protocol agent. [0022] In one embodiment, each protocol agent contains one or more buffers that may be used to store data, commands, or addresses originating from one of the cache agents, which can then be retrieved from the buffers in the proper order to be delivered to a particular cache agent. In the embodiment illustrated in FIG. 2 , each protocol agent includes, or otherwise has associated therewith, two first-in-first-out (FIFO) buffers 216 , 217 , 218 , 219 that are each coupled to two of the four rings of FIG. 2 . Each pair of rings illustrated can communicate information in a particular direction. For example, rings 211 and 212 can communicate information in a clockwise (CW) direction, whereas rings 213 and 214 can communicate information in a counter-clockwise (CCW) direction. In an alternate embodiment, only a single FIFO is used and only two of the four rings are used. [0023] FIG. 3 is a diagram illustrating the ring structure of FIG. 2 in conjunction with various routing circuits, which route data to their intended recipient from each of the cache agents. In particular, FIG. 3 illustrates a number of cache agents, identified by the letter “C”, in a ring configuration of two networks, each comprising signals AD and AK to interconnect a cache agent with a protocol agent, identified by the letter “S”. A routing circuit, identified by the letter “R”, is associated with each cache agent to either route information contained within signals, AD and AK, to the next cache agent within a network (if the next agent in the network is not a protocol agent) or to a protocol agent (if the next agent within the network is a protocol agent). [0024] Two of the routing circuits 310 and 315 couple the rings of the networks in FIG. 3 to the protocol agents, whereas other routing agents connect the rings to other cache agents and other ring networks. In one embodiment, a cache agent 307 may send a signal intended for one of the protocol agents on ring 301 in a clockwise direction. The routing agents between cache agent 307 and the intended protocol agent, moving in a clockwise direction around the ring, propagates the information contained within the signal between them until the signal reaches the routing circuit, 310 or 315 , which would route the signal to the intended protocol agent. For example, the signal described above would be retrieved by protocol agent 307 and the information within would be stored in the appropriate FIFO. [0025] After information is stored within the FIFOs of a particular protocol agent, the protocol agent may process the cache events sent by the cache agent in accordance to the coherence protocol by retrieving, or “popping,” the information off of the FIFO in the order in which it was stored. [0000] Ordering Rules [0026] As discussed above, because the cache agents (e.g., cache controllers) are separate from the protocol agent, the coherence ordering point is not at the same location, particularly since there is a non-one-to-one mapping between cache controllers and protocol engines with a variable latency Chip Multi Processor (CMP) network in between. [0027] More specifically, a cache controller performs cache actions, such as requests, writebacks, snoops, and fills in an internal order, and when applied in a sequence to a single block in the cache, results in the data and state of the block to be updated in the order according to the specific sequence. This ordered sequence of cache events is important to correctly implement the coherence protocol. For instance, in one embodiment, the communication of correct cache ordering allows snoop responses and new requests to be seen in the correct order by the detached protocol agent, giving it the visibility into the internal ordering at the cache controller for these events, thereby ensuring that a snoop doesn't incorrectly get reordered behind a request and become blocked. The cache ordering point is where cache events, such as snoops, request, writebacks, and fills are ordered with respect to one another. The coherence ordering point is where coherence decisions are made from events specifically necessary to implement the protocol state transitions. These events include the cache events set forth herein, which are brought into the protocol agent in the correct cache event ordering via the pre-coherence channel, along with external coherence events, which reflect the communication of the coherence view from other protocol agents in the system. [0028] In one embodiment, the cache ordering point is made to appear as if it's located inside the protocol agent, which is located in the system interface instead of the cache controller. To do that, information contained in the cache agent's ordering point is shifted into the coherence ordering point via the pre-coherence channel. [0029] In one embodiment, the pre-coherence channel gives a protocol agent a minimal view into the internal ordering at the cache agents, allowing the protocol agent to function in a detached way without violating coherence rules in the coherence protocol. In one embodiment, it recognizes what type of ordered cache events are important and thus need to be communicated in the pre-coherence channel to the protocol agent In one embodiment, the pre-coherence channel consists of an ordered mechanism to transport cache events from the cache agent into the protocol agent, and includes recovery and ignore mechanisms to allow a consistent coherence view of the system. The pre-coherence channel also includes a mechanism where resource dependencies are resolved by blocking the pre-coherence channel or moving the blockage to another FIFO to unblock the pre-coherence channel. [0030] The use of pre-coherence channel ordering enables the cache agents to be detached from protocol engines. This provides a number of advantages such as, for example, the following advantages. First, it allows each protocol to be optimized for their own intended purposes (local protocol optimized for cache transfer performance, and off-chip protocol to support the complex conflict and coherence completion rules). Second, it modularizes the overall chip design. Third, it allows more effective resource sharing between the local cache agents in a multiple cache agent design. Fourth, the local protocol hides on-chip coherence operations from off-chip protocol, so off-chip bandwidth is saved. [0031] In one embodiment, the pre-coherence channel is implemented as a virtual ordered route by which cache specific information is communicated from the cache agent into the specific logic that maintains the system interface's coherence ordering point, which is a request inflight table referred to herein as the missing address file (MAF), located in the protocol agent. Physically, this virtual route is implemented as the CMP network, and egress and ingress buffering on either side of the network within the cache and protocol agents respectively leading from the cache control logic to the MAF. The CMP network is the link and physical layers of the an on-chip communication consisting of the CMP address, acknowledgement, and data networks, between cache agents, processors, and protocol agents, shown as the collective of the bus network and its routing components in FIG. 3 . [0032] In one embodiment, the pre-coherence channel ordering is relaxed to allow a certain degree of out-of-ordering to lessen the restrictions on the CMP network in cases where reordering effects can either be (1) recovered, or (2) ignored because they do not cause the cache and protocol agent's states to diverge. [0033] Since the protocol agent is apart from the cache agent, cache ordering needs to be communicated into the protocol agent. A set of rules is set forth herein by which a cache agent communicates the cache ordering into the protocol agent across a CMP network to a protocol agent. [0034] In one embodiment, the following message types communicate the ordering point from the cache controller into the system interface: requests, writebacks, data (fill) acknowledgements, and snoop responses. These messages come into the protocol agent as a single input stream of events. From the dependency point of view, in one embodiment, they are classified into three types: simple flow dependency, cyclic resource dependency, and acyclic resource dependency. [0035] For a simple flow control dependency, data acknowledgement and snoop responses do not require allocation of a resource in order to be consumed. In one embodiment, they both could potentially create home channel messages, which are sunk in preallocated buffers in the home node of the system, thus, not requiring additional dependency aside from message flow control. (The home node may be part of the memory controller in a system responsible for connecting each of the processors in the system to the memory controller, and these transactions are used to implement a coherence protocol in which these processors and the home node coupled to the memory controller jointly participate.) [0036] For a cyclic resource dependency, requests depend on the allocation of a resource. In one embodiment, because resource sharing (as opposed to resource division) is allowed, a request may not have a free MAF entry to allocate. In order to make room for allocation, another entry needs to retire, and for that to occur, snoops need to make forward progress. If a request is blocking the input event stream, then snoop responses behind the request are prevented from making forward progress. As long as snoop responses are blocked, the protocol engine cannot complete requests, and request entries in the MAF will not retire, which is a deadlock condition. Request allocation depends on request forward progress, which depends on snoop forward progress, which depends on the event stream making forward progress, which is blocked by the request. [0037] For acyclic resource dependency, writeback transactions also have a resource dependency on allocation into the MAF. While blocking on a MAF entry to become available, the input stream from the cache agent is also blocked. However, this is a benign resource dependency because writeback forward progress is not dependent on the any messages behind it, namely, a snoop response message following it from the cache agent. As long as there is a reserved writeback allocation path into the MAF, writebacks can achieve still forward progress even by blocking the input event stream. [0038] FIG. 4 is a block diagram of one embodiment of message ordering logic to accommodate the various message types while ensuring the proper ordering of the cache coherency events. In one embodiment, this logic is in the protocol agent. The ordering logic uses two separate FIFOs and includes the MAF. [0039] Referring to FIG. 4 , an incoming stream of events is impact into ingress queue (e.g., FIFO) 403 . Such events are received from the pre-coherence channel ordering interface (e.g., rings) between the one or more protocol agents and one or more caches (e.g., cache agent 401 ) in the sets of caches. These events are received in the form of messages that include requests, writebacks, data acknowledgements, snoop no data messages, and snoop data messages. [0040] The head of ingress FIFO 403 is coupled to one input of arbiter 405 . In one embodiment, only the head of ingress FIFO 403 is allowed to arbitrate for input into MAF 406 . In one embodiment, non-request events are allowed to block at the head of ingress FIFO 403 while waiting for resources, but if a request is at the head of ingress FIFO 403 and blocked, it is moved into spill FIFO 404 instead, thereby allowing the stream of events following it in ingress FIFO 404 to proceed to avoid deadlock. In one embodiment, the move is done by obtaining an issue slot by doing a poison issue when not all the resources are available. The poison issue is one which is interpreted as a nop elsewhere, but enables allocation into spill FIFO 404 . [0041] In one embodiment, spill FIFO 404 is preallocated with the total number of requests from all cache agents from which the protocol agent can receive. In one embodiment, unallocated requests have one way pre-coherence ordering with respect to the other messages. Thus, an unallocated request cannot shift forward in the pre-coherence channel but is allowed to move backwards. In other words, the protocol agent pretends the cache agent request was sent later than it was with respect to snoops following it. Additionally requests are out-of-order with respect to each other. Subsequently, arbiter 405 arbitrates between the outputs of ingress FIFO 403 and spill FIFO 404 . [0042] Thus, from the dependency point of view, requirements are made on the reordering of requests in comparison to all other events in the pre-coherence channel ordering. In these reordered cases, reordering is done on the pre-coherence channel where it would not have been allowed in at the system interface. These happen in cases where either the protocol agent is able to recover, or the reordered perception of events do not force the cache and coherence agents to diverge. The following matrix describes what may or may not be allowed to reorder in one embodiment: X followed Snoop Data Snoop No by Y Request Writeback Hit Data Data Ack. Request Unordered(1) Ordered(2) Ordered(2) Unordered(7) Unordered(1) Writeback Must allow Ordered(2) Unordered(6) Unordered(8) Unordered(5) reorder(3) Snoop Data Must allow Ordered(2) Unordered(6) Unordered(8) Unordered(5) Hit reorder(3) Snoop No Must allow Ordered(2) Ordered(2) Ordered(2) Unordered(5) Data reorder(3) Data Ack. Impossible Impossible Ordered(4) Ordered(4) Impossible [0043] (1) Multiple requests to the same address can be inflight from the cache agent, or a new request could come from the cache agent before the old one has been retired. In one embodiment, a CAM is implemented in the protocol agent to serialize the requests and guarantee there's only one outstanding request to an address in the system. This is provided so that the rejected second requires will be able to fairly arbitrate the next time. [0044] (2) A request, writeback, or snoop response need to be ordered behind prior writebacks and snoop responses. In one embodiment, out-of-order events between cache and protocol agents for these event sequences cannot be changed to make a coherent series of events through pre-coherence channel architecture efforts, so they are disallowed. [0045] (3) A snoop response or writeback following a matching request are required to be able to pass ahead of a blocked request to avoid deadlock. [0046] (4) In one embodiment, a data acknowledgment could trigger the coherence protocol to enter a conflict phase, if earlier snoop responses have resulted in conflict against the same transaction receiving the data acknowledgements. Therefore, the correct ordering of snoop responses versus data acknowledgement is communicated on the pre-coherence channel to ensure conflicts are properly detected to allow entrance into conflict phase. [0047] (5) In one embodiment of the coherence protocol, cache replacements and snoops on the returned data are allowed to occur in the cache agent prior to the coherence agent completing the transaction. These are allowed to merge into the active transaction and activate once the transaction is complete. Thus, the pre-coherence channel ordering allows these to be reordered ahead of the data acknowledgement, so that they merge into the transaction before it is potentially completed by the data acknowledgement. A recovery method is used to buffer early extracted data from writebacks and snoop data hits and unbuffer and covert to writebacks after completion of the said request. [0048] (6) These cases are only for fetch type requests, for which the peer agent is only obligated to give a recent (non-infinitely-stale) version of the data. A snoop response can be unordered with a writeback or another snoop response to return an almost current data. [0049] (7) A snoop miss passed by a request is registered as a conflict, which is an ignored side-effect. [0050] (8) These could only happen in the following sequence: snoop miss→data ack.→writeback or snoop hit. In one embodiment, the fill operation occurs in the middle. One pre-coherence channel implementation relies on the MAF to buffer the writeback or snoop hit into the inflight request waiting for the data acknowledge, and then recovering through unbuffer and conversion to writeback. [0051] The ordering requirements may be hardened in an implementation to make unordered relations ordered, but the table above defines the loosest relations between the messages that must travel on the CMP network into the coherence point in MAF 406 . Additionally, the request dependency requirements are satisfied in all parts of the network to avoid request deadlock. [0052] In one embodiment, ingress FIFO 403 and spill FIFO 404 in the system interface could be part of the CMP network. All requests, writebacks, snoop responses, and data acknowledgements are explicitly made ordered in the FIFO, even though the pre-coherence channel does not require all of them to be ordered. Request dependency is fixed through spill FIFO 404 , which then allows requests to be unordered amongst requests to take advantage of rule 1 . [0053] In one embodiment, the interconnect is a network of rings optimized for cache transfer between cores and caches. In one embodiment, there are three different types of ring networks to facilitate this: address, no-address, and data. In one embodiment, every message is one phit in length and the three ring networks exist to balance the message load between the rings. For instance, a read request on address is balanced by a cache response on data. Each of the ring networks is arbitrated separately. A ring guarantees point-to-point ordering, but ordering across different rings can be skewed, so keeping ordering across ring networks means ordered injection into the ring networks from a source. [0054] To benefit most from the out-of-orderness allowed by the pre-coherence channel on this rings-based architecture, messages are split across address and no-address networks in the following way. Requests, writebacks, and snoop data hits are placed on the address network, and snoop no data and data acknowledgements are placed on the no-address network. Messages on each network are ordered between themselves. Two rings allow bandwidth to be doubled. In one embodiment, address ring injection does not need to be ordered with no-address ring injection, but the reverse requires order. That is, an address can pass no-address but not vice-versa. [0055] Once into the protocol agent, all messages are piled into ingress FIFO 403 in the order they're received, which is the order the cache agent intends. No further reordering of messages occur in ingress FIFO 403 as they are pulled out and sent to be issued into MAF 406 in order under control of arbiter 405 . The out-of-orderness introduced on the ring network, but sill complying to the pre-coherence channel ordering, is reflected in ingress FIFO 403 , along with request out-of-orderness, which is introduced local to the system interface at the FIFO 404 , through arbiter 405 across the FIFOs into MAF 406 . The sum of out-of-orderness seen at MAF 406 is either corrected with special effort in the protocol agent such as rules 5 and 8 , or rationalized away to not affect the overall picture of the coherence protocol as in rules 1 , 3 , 6 , and 7 , in one embodiment of an implementation of a coherence protocol at MAF 406 . From that point on, messages travel on the coherence channel on or off-chip between protocol agents in the system. [0056] FIG. 5 illustrates a front-side-bus (FSB) computer system in which one embodiment of the invention may be used. A processor 505 accesses data from a level one (L1) cache memory 510 and main memory 515 . In other embodiments, the cache memory may be a level two (L2) cache or other memory within a computer system memory hierarchy. Furthermore, in some embodiments, the computer system of FIG. 5 may contain both a L1 cache and an L2 cache. [0057] Illustrated within the processor of FIG. 5 is one embodiment 506 . The processor may have any number of processing cores. Other embodiments, however, may be implemented within other devices within the system, such as a separate bus agent, or distributed throughout the system in hardware, software, or some combination thereof. [0058] The main memory may be implemented in various memory sources, such as dynamic random-access memory (DRAM), a hard disk drive (HDD) 520 , or a memory source located remotely from the computer system via network interface 530 containing various storage devices and technologies. The cache memory may be located either within the processor or in close proximity to the processor, such as on the processor's local bus 507 . [0059] Furthermore, the cache memory may contain relatively fast memory cells, such as a six-transistor (6T) cell, or other memory cell of approximately equal or faster access speed. The computer system of FIG. 5 may be a point-to-point (PtP) network of bus agents, such as microprocessors, that communicate via bus signals dedicated to each agent on the PtP network. Within, or at least associated with, each bus agent may be at least one embodiment of invention 506 , Alternatively, an embodiment of the invention may be located or associated with only one of the bus agents of FIG. 5 , or in fewer than all of the bus agents of FIG. 5 . [0060] FIG. 6 illustrates a computer system that is arranged in a point-to-point (PtP) configuration. In particular, FIG. 6 shows a system where processors, memory, and input/output devices are interconnected by a number of point-to-point interfaces. [0061] The system of FIG. 6 may also include several processors, of which only two, processors 670 and 680 are shown for clarity. Processors 670 and 680 may each include a local memory controller hub (MCH) 672 and 682 to connect with memory 22 , 24 . Processors 670 and 680 may exchange data via a point-to-point (PtP) interface 650 using PtP interface circuits 678 and 688 . Processors 670 and 680 may each exchange data with a chipset 690 via individual PtP interfaces 652 and 654 using point to point interface circuits 676 , 694 , 686 and 698 . Chipset 690 may also exchange data with a high-performance graphics circuit 638 via a high-performance graphics interface 639 . Embodiments of the invention may be located within any processor having any number of processing cores, or within each of the PtP bus agents of FIG. 6 . [0062] Other embodiments of the invention, however, may exist in other circuits, logic units, or devices within the system of FIG. 6 . Furthermore, other embodiments of the invention may be distributed throughout several circuits, logic units, or devices illustrated in FIG. 6 . [0063] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. However, it will be understood by those skilled in the art that the claimed subject matter may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the claimed subject matter. [0064] Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. [0065] In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.

A cache architecture to increase communication throughput and reduce stalls due to coherence protocol dependencies. More particularly, embodiments of the invention include multiple cache agents that each communication with the same protocol agent. In one embodiment, a pre-coherence channel couples the cache agents to the protocol agent to enable the protocol agent to receive events corresponding to cache operations from the cache agents to maintain ordering with respect to the cache operation events.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an apparatus for setting a liner in a well casing. 2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 & 1.98 During the construction of oil and gas wells a wellbore is drilled in the ground. After a certain depth is reached drilling is halted and a well casing lowered down the wellbore and cemented in place. Drilling is then recommenced until the wellbore reaches the next predetermined depth. At this stage drilling is halted and a liner lowered down the well casing. The liner is suspended from the well casing by a device known as a liner hanger which acts between the liner and the well casing. The liner hanger can be set mechanically or hydraulically. U.S. Pat. No. 3,291,220 shows an apparatus for setting a liner in a well casing, which apparatus comprises a liner hanger and a running tool. The running tool is provided with a valve seat obstruction of which will, in use, allow fluid pressure to be developed to set the liner hanger in the well casing. Once the liner hanger has been set the running tool is rotated anti clockwise to unscrew the running tool from the liner hanger. The running tool is then recovered. BRIEF SUMMARY OF THE INVENTION The present invention is characterised in that after the liner hanger has been set the application of further pressure will displace the valve seat to enable the running tool to be released and to allow fluid flow through the running tool. Preferably, the liner hanger comprises a plurality of slips which are mounted on a ring which is restrained against motion by a shear member. Advantageously, the liner hanger is provided with a packer and a member which, in use, applies pressure to the packer to deform it to occupy the space between said liner hanger and the well casing. Preferably, the apparatus includes a plurality of slips, at least one of which is attached to the member by a shear member, the arrangement being such that when pressure is applied to the member via the slips the packer deforms to occupy the space between the liner hanger and the well casing, and subsequently the shear member fails so that the slips move into a position between the member and the well casing to retain the packer in its deformed position. Advantageously, the slips form part of a polished bore receptacle. Preferably, the running tool comprises a liner support unit which comprises a body, a unit which extends outwardly from the body and engages one of the liner and the liner hanger, and wherein the valve seat is disposed in the liner support unit and is releasably attached thereto by a shear member. Advantageously, the apparatus includes at least one member which acts between the valve seat and the unit to maintain the unit in the extended position. Preferably, the liner support unit comprises the body, a support which is fast with or integral with the body, and a ring which is slidably mounted on the body, rests on the support, and accommodates the unit, the arrangement being such that when the unit is in its extended position the body and the support can be moved relative to the ring and the unit accommodated thereby to a secondary release position in which the unit can move radially inwardly. Advantageously, the body is provided with a recess to accommodate the unit when the body is in the secondary release position. Preferably, the running tool is provided with a lug which rests on the liner hanger, and the liner hanger is provided with a slot which, when the lug is moved into alignment with the slot allows the running tool to be moved relative to the liner hanger and the liner support unit to be moved to its secondary release position. Normally the liner is provided with both a liner hanger and a polished bore receptacle which extends upwardly from the liner hanger and is fitted with a junk bonnet which acts between the polished bore receptacle and the running tool to inhibit debris, for example cement, coming into contact with the many parts of the running tool whose operation could be inhibited or prevented by the ingress of debris. Previously, after the liner has been set and cemented in position the final step has been to raise the running tool to an extent such that the junk basket is removed from the top of the polished bore receptacle. At this stage spring loaded lugs move outwardly from part of the running tool so that when the running tool is subsequently lowered the lugs bear on the polished bore receptacle which actuates the packer between the liner and the well casing. During this time debris is free to enter the tool and the polished bore receptacle which is undesirable both because of the prolonged exposure of the running tool to debris and the fact that debris can accumulate in the details of the liner hanger and polished bore receptacle impairing re-entry of the running tool should this be required. According to another aspect of the present invention there is provided an apparatus for setting a liner in a well casing, which apparatus comprises a liner, a liner hanger, a polished bore receptacle, a packer which can be actuated by applying downward pressure to said polished bore receptacle, a running tool, and a junk bonnet which extends between said polished bore receptacle and said running tool and inhibits the ingress of debris into said polished bore receptacle, characterised in that said junk bonnet and said running tool are provided with means which, when said running tool is raised sufficiently, without removing said junk bonnet from said polished bore receptacle, co-operate so that if said running tool is subsequently lowered downward force applied to said running tool will be applied to said polished bore receptacle to set said packer. Preferably, said means comprises a lip which extends radially outwardly from said running tool, and a hook which is biased radially inwardly from said junk bonnet. Advantageously, said apparatus includes a ring which is disposed to restrict radial inward movement of said hook but which can be displaced by said lip to allow such movement. Preferably, the junk bonnet comprises a unit which extends outwardly therefrom and engages the polished bore receptacle to inhibit separation thereof, and the unit is maintained in the extended position by a ring which is displaceable to enable said unit to move out of engagement with the polished bore receptacle. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS For a better understanding of the present invention reference will now be made, by way of example, to the accompanying drawings, in which: FIGS. 1A, 1B and 1C together show a side view, partly in cross-section, of an apparatus in accordance with the present invention in use; and FIG. 2 is a section taken on line II--II of FIG. 1 with parts omitted for clarity. DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1A, 1B and 1C of the drawings there is shown a liner 1 which is suspended within a well casing 2 by a running tool 100 which is attached to the bottom of a drill string (not shown). The top of the liner 1 is attached to a liner hanger which is generally identified by reference LH. A polished bore receptacle 22 extends upwardly from the top of the liner hanger (LH). The running tool 100 comprises an upper tubular member 3 and a lower tubular member 17 which are connected by a liner support unit (LSU) which is provided with a plurality of teeth units 16 which extend radially outwardly into grooves in the liner hanger LH and releasably connect the liner hanger LH to the running tool 100. The teeth units 16 are maintained in position by dogs 15 which are themselves maintained in position by dog keepers 13 and 14 which are in turn maintained in position by a valve seat 5 which is held in the liner support unit LSU by a shear pin 12. The liner support unit LSU comprises a body 26 having a support 25 fast thereon. Ring 29 which accommodates the teeth units 16 is a push fit on the body 26. In operation the liner 1 is lowered on the running tool 100. The weight of the liner 1 is supported by the liner hanger (LH) which bears on the teeth units 16 which are supported by the support 25 fast with the body 26. During this operation it is not uncommon for the liner 1 to become blocked by an obstruction. A common method of removing such obstructions is to pump fluid, typically drilling fluid, down through the liner 1 until the obstruction is removed whereafter the liner 1 can be further lowered. When the liner 1 reaches the required position a ball 4 is released into the drill string. The ball 4 passes through the drill string and the upper tubular member 3 of the running tool 100 and comes to rest on the valve seat 5. Fluid is then pumped down the drill string. Since the passage of fluid is blocked by the ball 4 the pressure is transmitted through holes 7 and 8 and acts on ring 9 which is restrained by shear pin 6. When the pressure of the fluid reaches about 103 bar (1500 psi) the shear pin 6 fails which enables ring 9 to move upwardly. The ring 9 is provided with a plurality of separate and distinct slips 10 which, as the ring 9 moves upwardly, are forced outwardly by the tapered surface on a ring 11 until they engage the well casing 2. Once the slips 10 have moved to their outermost position the fluid pressure is again increased until at about 172 bar (2500 psi) the shear pin 12 fails. The ball 4 and valve seat 5 travel down the lower tubular member 17 until they land on the floor thereof (not shown) below port 18. As the valve seat 5 moves downwardly the dog keepers 13 and 14 are no longer restrained nor are the dogs 15 or the teeth units 16. Accordingly, when an upward force is applied to the running tool 100 the teeth units 16 should (if they have not already done so) move radially inwardly to allow the running tool 100 to be raised. It will be noted that the release of the valve seat 5 permits separation of the running tool 100 from the liner 1. Furthermore, fluid flow through the running tool 100 is now re-enabled with the fluid leaving the running tool 100 via outlets including outlet 18 disposed along the length of the lower tubular member 17. Should the liner 1 fail to separate from the running tool 100 in the manner described, for example by failure of the shear pin 12 to fracture or the valve seat 5 jamming, the running tool 100 includes a secondary release mechanism which is generally identified by reference SRM. The secondary release mechanism (SRM) comprises three lugs 24 which project radially from a boss fast with the upper tubular member 3 of the running tool 100. In its normal position the lugs 24 overlie the top of the liner hanger (LH) and consequently prevent the running tool 100 being lowered beyond the position shown with respect to the liner hanger (LH). (In this connection the lug 24 has been illustrated displaced slightly anti-clockwise of its normal position to facilitate understanding of its operation.) However, if the tool string is rotated anti-clockwise the lugs 24 come into alignment with longitudinally extending slots 28 in the liner hanger (LH). When this occurs the running tool 100 can be lowered sufficient to displace the body 25 of the liner support unit (LSU) (together with the support 25, ring 29, dogs 15, dog keepers 13, 14, valve seat 5, ball 4 and shear pin 12) downwards sufficient to bring the teeth units 16 into alignment with a recess 30 in the body 26 of the liner support unit LSU and thus allow the teeth 16 to move into the recess 30 and release the liner 1 from the running tool 100. It should perhaps be emphasised that the support 25 is fast with the body 26 of the liner support unit LSU whereas the ring 29 merely fits snugly over the body 16 but can be removed therefrom with the application of only a light force. It will be appreciated that great care must be taken to ensure that the secondary release mechanism (SRM) does not operate inadvertently and accordingly the secondary release mechanism (SRM) includes a damper so that the lugs 24 can only come into alignment with the slots 28 if a sufficient anti-clockwise force, for example 3500 ft·lbs of left-hand torque, is applied to the drill string for a sufficient time, for example 30 seconds. In order to achieve this the secondary release mechanism (SRM) incorporates a damper unit which is better shown in FIG. 2. In particular, the damper unit comprises a rotor which forms part of the upper tubular member 3 of the running tool 100 and a stator 31 which is provided with three lugs 27 which project into the slots 28. The rotor is provided with three radially outwardly extending vanes 33 whilst the stator 31 is provided with three radially inwardly extending vanes 34. The spaces between the vanes are filled with grease 36. In use, when an anti-clockwise force is applied to the running tool 100 the rotor attempts to move anti-clockwise. However, this movement is resisted by the grease which slowly oozes past the minute clearance between the radial extremities of the vanes 33 and the inside of the stator 31. This delays the lugs 24 coming into alignment with the slots 28 unless a sufficient anti-clockwise force is applied for a sufficient time. When a clockwise force is applied, as in normal operation, the stator 35 moves to the position shown in FIG. 2 where the vanes 33 abut the vanes 34. In this position clockwise rotation of the drill string is transmitted to the liner hanger LH via the lugs 27 and the slots 28. Such rotation can be extremely helpful for facilitating the running of the liner 1 and during the subsequent cementation operation. In this connection, it will be noted that the liner hanger (LH) is provided with a bearing above the ring 11 to facilitate rotation of the liner 1 after the liner hanger (LH) has been set. Historically, the practice at this stage would have been to completely withdraw the running tool 100 and then cement the liner 1 in position. However, the practice now is to raise the running tool 100 by a small distance to confirm that the liner 1 has been separated from the running tool 100 and then proceed with cementing through the drill string and running tool 100. With this in mind, the top of the polished bore receptacle 22 is provided with a junk bonnet 20 which is intended to prevent material entering the polished bore receptacle 22 particularly during the cementing operation. The junk bonnet 20 comprises a seal 19 which slidably engages the outer wall of the upper tubular member 3 and a seal 21 which engages the inner wall of the polished bore receptacle 22. The junk bonnet 20 is maintained in the polished bore receptacle 22 by teeth units 44 which project into grooves in the polished bore receptacle 22. The junk bonnet 20 is also restrained from rotation by a spring loaded pin 45 which is mounted in the junk bonnet 20 and which projects into a recess in the top of the polished bore receptacle 22 as shown. The teeth units 44 are maintained in the radially extended position shown by a ring 46 which is held in place by a shear pin 43. The bottom of the junk bonnet 20 is provided with an inwardly extending flange 35 which supports a plurality of hooks 47 which are biased radially inwardly by a resilient pad 48 but are restrained by a ring 49 secured to the junk bonnet 20 by a shear pin 50. The upper end of the hooks 47 rest on a bearing race 38 as shown. In operation after the liner hanger LH has been set and the running tool 100 disconnected the running tool 100 is raised a short distance to confirm that disconnection has occurred. The running tool 100 is then lowered to relocate the lugs 27 in the slots 28. Cementing then proceeds. This involves pumping cement down the drill string, through the running tool 100 and down the liner 1. The cement is supplied under pressure and consequently is squeezed up through the annular space between the liner 1 and the wellbore until it reaches the bottom of the well casing 2 when it passes up through the annular gap between the liner 1 and the well casing 2. During this time the liner 1 is rotated to enhance the distribution and compaction of the cement. Eventually the cement rises up between the liner 1 and the well casing 2 and a thin layer of cement covers the top of the junk bonnet 20. At this time the running tool 100 is raised until the lip 32 enters the bottom of the junk bonnet 20. The lip 32 displaces the hooks 47 radially outwardly and then bears upwardly on the ring 49 until the shear pin 50 fails. As the ring 49 is pushed further up inside the junk bonnet 20 the hooks 47 move radially inwardly so that when the running tool 100 is lowered the lip 32 is supported on the hooks 47. Downward force (typically 6800 kg (15,000 lbs)) is applied to the running tool 100. This force is applied to the junk bonnet 20 via the lip 32 and is transmitted to the polished bore receptacle 22. It will be noted that when the running tool 100 was raised the stator 31 of the secondary release mechanism (SRM) also moved upwardly leaving the teeth units 51 connecting the polished bore receptacle 22 to the liner hanger LH unsupported. If the teeth units 51 have not already done so the application of downward force to the polished bore receptacle 22 displaces the teeth unit 51 inwardly and also shears sheet pin 37. As the polished bore receptacle 22 moves downwardly the packer 40 is squeezed downwardly and deformed outwardly against the well casing 2 by the core member 39. Further downward pressure (typically 18,200 kg (40,000 lbs)) fractures shear pin 41 causing the slip 42 to move outwardly over the cone member 39 and lock the packer 40 in position. The running tool 100 is now raised so that the lip 32 bears against the ring 49 which in turn bears against the ring 46 until the shear pin 43 fails after which the teeth unit 44 can enter the recess in the ring 49 and the entire running tool 100 can be raised to the surface together with the valve seat 5, ball 4, teeth units 16 and any other debris which will have collected on the floor of the lower tubular member 17 below the port 18. If it is not possible to fracture the shear pin 43 by a straight pull this may be accomplished by a combination of rotating the drill string and pulling. The spring loaded pin 45 facilitates this operation by preventing the junk bonnet 20 rotating in concert with the upper tubular member 3. At the completion of the operation only the well casing 2, the liner 1, the liner hanger (LH), its components and the polished bore receptacle 22 should remain in the wellbore. By way of background, it should be noted that the packer 40 is set to ensure fluid tightness between the liner 1 and the well casing 2 even though there is cement between these components It should also be noted that not all liners are cemented in place in which case the packer 40 is set immediately after the liner hanger (LH) has been set and the running tool 100 separated from the liner hanger (LH).

A system for setting a liner in a well casing which has a liner, a liner hanger, a polished bore receptacle, a packer which can be actuated by applying downward pressure to the polished bore receptacle, a running tool, and a junk bonnet which extends between the polished bore receptacle and the running tool and inhibits the ingress of debris into the polished bore receptacle, the junk bonnet and the running tool provided with apparatus which, when the running tool is raised without removing the junket bonnet from the polished bore receptacle, the apparatus cooperate so that when the running tool is subsequently lowered downward force applied to the running tool will be applied to the polished bore receptacle to set the packer, wherein the apparatus comprises a lip which extends radially outwardly from the running tool, and a hook which is biased radially inwardly from the junk bonnet and including a ring which is disposed to restrict radial inward movement of the hook but which can be displaced by the lip to allow such movement.

FIELD OF THE INVENTION This invention relates to inhalation activatable dispensers for use with inhalers such as dry powder dispersers and aerosol container assemblies which contain medicaments for inhalation therapy, are pressurized with liquid propellants, and include a metering valve through which a series of metered medicament doses can be dispensed. In particular the invention relates to inhalation activatable dispensers which are removably retained within an outer casing. BACKGROUND TO THE INVENITON Inhalation activatable dispensers for use with aerosol container assemblies of the type described above are known, their general purpose being to afford proper coordination of the dispensing of a dose of medicament with the inhalatin of the patient thereby allowing the maximum proportion of the dose of medicament to be drawn into the patient's bronchial passages. Examples of such dispensers are described in British Patent Specification Nos. 1,269,554, 1,335,378, 1,392,192 and 2,061,116 and U.S. Pat. Nos. 3,456,644, 3,645,645, 3,456,646, 3,565,070, 3,598,294, 3,814,297, 3,605,738, 3,732,864, 3,636,949, 3,789,843 and 3,187,748 and German Patent No. 3,040,641. European Patent No. 147028 discloses an inhalation activatable dispenser for use with an aerosol container in which a latch mechanism releasing vane is pivotally mounted in an air passage between an aerosol outlet valve and a mouthpiece, which latch mechanism cannot be released if force to activate the dispenser is not applied before a patient inhales. The dispenser generally comprises a housing having a mouthpiece and an air passage therethrough terminating at the mouthpiece, the housing being adapted to receive an aerosol container having a support block with a socket adapted to receive the stem of the valve of the aerosol container and a through orifice communicating between the socket and the air passage, and latch means having parts movable between an engaged position in which movement of the container and the support block toward each other upon the application of a force to bias the container and the support block toward each other is prevented and a release position in which movement of the container and the support block toward each other in response to said force is permitted causing the stem to move to its inner discharge position, the latch means comprising a vane mounted on the housing in the air passageway between the orifice and the mouthpiece for movement toward the mouthpiece under the influence of inhalation through the mouthpiece to release the latch means in which the vane moves toward the mouthpiece from a blocking to a nonblocking position with respect to the passageway in response to inhaling at the mouthpiece and releases the latch means only during the application of said force to bias the container and support block toward each other. This inhalation device has been received favourably by patients and doctors since it not only overcomes the hand-lung coordination problem but it does so at a very low triggering flow rate (approximately 30 liters/minute) essentially silently, and with a very compact design barely larger than a standard inhaler. It is an object of the present invention to provide an inhalation activable dispenser within an outer casing. BRIEF SUMMARY OF THE INVENTION Therefore according to the present invention there is provided: (i) a breath-actuated inhaler comprising a medicament reservoir mounted within a housing which comprises a mouthpiece and breath-actuation means which prevents dispensing from the reservoir until a patient inhales through the mouthpiece, and, (ii) a protective casing surrounding the breath actuated inhaler, the casing comprising a body portion and a movable cover which may be displaced to allow a patient access to the mouthpiece to use the breath-actuated inhaler whilst it is within the casing, the breath-actuated inhaler being removable from the protective casing and operable outside the casing. The arrangement of a removable breath-actuated inhaler within a protective casing has several advantages. The casing surrounds and preferably completely envelopes the inhaler preventing ingress of dust, water and other foreign bodies allowing the inhalation device to be readily carried in a pocket, handbag etc. The inhaler may be used without removing it from the casing by displacing the cover to allow patient access to the mouthpiece. The casing also protects the inhaler, particularly the breath-actuated mechanism, from direct damage and if the casing is damaged the inhaler will probably still function from within the casing. However, if the casing is subjected to severe damage the inhaler may be removed and used in its breath-actuated mode outside the casing. In a preferred embodiment the breath-actuated inhaler comprises means to disable the breath-actuated mechanism thereby allowing the inhaler to be used in a simple press-and-breathe mode which allows test firing. DESCRIPTION OF PREFERRED EMBODIMENTS The inhaler preferably comprises an aerosol vial containing a mixture of propellant and medicament and equipped with a metering valve. However, the inhalation device of the invention may comprise a dry powder dispensing device in which the medicament is entrained in the air stream established by the patient's inspiratory effort. Examples of such devices are disclosed in our co-pending British Patent Application No. 8909891.7. Suitable breath-actuated mechanisms for use in the inhaler are known and are described, for example, in European Patent No. 147028. The breath-actuated mechanism requires a priming or cocking force which moves the aerosol container relative to the valve stem for dispensing when the breath-actuated mechanism has been actuated. In one arrangement of the invention the priming force may be provided by a cocking lever mounted through the protective casing or may be provided by a screw arrangement or when the cover is displaced e.g. by a sliding, lever, geared or cam action or a combination thereof. Alternatively, access to a cocking lever may be gained when the cover is displaced. The priming force may be applied directly to the aerosol container or to the valve e.g. via a nozzle block assembly. The priming force is preferably applied by the cover which may be pivotally mounted to displace upwardly or downwardly to provide access to the mouthpiece. Generally the priming force applied by the cocking lever, cover etc., results in compression of a spring which moves the aerosol container relative to the valve when the breath-actuated mechanism is triggered. When the inhaler is removed from the casing the priming force may be applied manually by squeezing the aerosol container and housing between thumb and finger in a similar manner to a conventional press-and-breathe inhaler. Alternatively, the inhaler may possess its own cocking lever to apply the primary force when the inhaler is removed from the casing. When the inhaler is within the casing the cocking lever may be uncovered for use when the cover is displaced or may interact with the cover to prime the inhaler during displacement of the cover. The inhaler is preferably capable of accommodating aerosol vials of different lengths to avoid the necessity of producing completely different devices for each size of vial. Different length vials may be accommodated by forming the body portion of the casing in two or more parts, one part being in the form of a sleeve or shroud which envelops the base and at least part of the body of the aerosol vial. A series of such sleeves may be fabricated to correspond to different lengths of aerosol vials. Alternatively, the body portion of the casing may have an aperture through which the aerosol vial extends thereby obviating the need for producing a range of different size components. The inhaler preferably incorporates means to provide an indication of the number of doses dispensed and/or remaining in the aerosol container. The indication is preferably visual and the housing of the inhaler and optionally the protective casing may have a transparent window or aperture for viewing. The invention will now be described with reference to the accompanying drawings in which: FIG. 1 represents a vertical cross-section through a breath-actuated inhaler suitable for use in the invention, FIG. 2 represents a vertical cross-section through the breath-actuated inhaler of FIG. 1 during operation, FIG. 3 represents a vertical cross-section through the breath-actuated inhaler of FIG. 1 in the press-and-breathe mode, FIG. 4 represents a vertical cross-section through an inhalation device in accordance with the invention which comprises the breath-actuated inhaler of FIG. 1 within a protective casing, FIG. 5 represents a vertical cross-section through the inhalation device of FIG. 4 showing the cover displaced, FIGS. 6a and 6b represent a perspective view and a cross-section through an alternative inhalation device in accordance with the invention, FIGS. 7a and 7b represent a perspective view and vertical cross-section through a further inhalation device in accordance with the invention, FIGS. 8a and 8b represent a vertical cross-section through the upper portion of a further inhalation device in accordance with the invention, FIGS. 9a and 9b represent a vertical cross-section through an upper portion of a further inhalation device in accordance with the invention, and FIGS. 10a and 10b represent a vertical cross-section through an upper portion of a further inhalation device in accordance with the invention. Referring to FIGS. 1 to 5, the breath-actuated inhaler comprises a housing (2) incorporating a mouthpiece (4) and contains an aerosol vial (6). The aerosol vial (6) may be of any suitable size and has a metering valve (not shown) possessing a hollow valve stem (8). The valve stem (8) is held within a nozzle block (10) which has a passage (12) in communication with the mouthpiece (4). Discharge of the metering valve is effected by relative movement between the valve stem (8) and the aerosol vial (6). The breath-actuation mechanism comprises a vane (14) which is pivotally mounted within the mouthpiece (4), a rocker element (15) which supports a catch (16) pivotally mounted on the rocker at (18). When the breath-actuated mechanism is in its blocking position as shown in FIG. 1 and a cocking force is applied in the direction of the arrows A, movement of the aerosol vial (6) relative to the valve stem (8) is prevented. Such movement is blocked by the rocker element (15), which is prevented from pivotal movement by the catch (16) having a curved surface (17) engaging the curved surface (20) of the vane (14). Thus, when the inhaler is in its breath-actuated mode it is not possible to dispense from the aerosol vial before inhalation through the mouthpiece (4). When a patient inhales through the mouthpiece as shown in FIG. 2, inhalation causes pivotal movement of the vane. The curved surface (20) of the vane (14) and the curved surface (17) of the catch (16) effectively act as co-operating roller surfaces. Pivotal movement of the vane causes the curved surface (20) to rotate in one direction resulting in curved surface (17) of the catch rotating in the opposite direction. This displacement of the catch moves from a blocking to an unblocking position allowing pivotal movement of the rocker element (15) which in turn allows movement of the vial (6) relative to the valve stem (8) under the influence of the cocking pressure causing the valve to fire. The inhaler also comprises a switch (22) which may convert the inhaler between a breath-actuated mode and a press-and-breathe mode as may be required for test firing. The switch (22) is pivotally mounted within the housing (2) and comprises a finger (24) which is capable of engaging the catch (16). When the switch (22) is in the breath-actuated mode as shown in FIGS. 1 and 2 there is no engagement between the finger (24) and the catch (16). However, when the switch (22) is pivoted to the press-and-breathe mode as shown in FIG. 3, the finger (24) engages the catch (16), pivoting the catch (16) away from the vane (14) to its unblocking position thereby allowing free movement of the aerosol vial (6) relative to the valve stem (8). In the press-and-breathe mode the valve may be fired at any time. During use the patient will be required to coordinate the cocking force and breathing in order to attain an effective dose. The vane (14) will simply pivot to the roof of the mouthpiece during inhalation. The breath-actuated inhaler additionally comprises means to provide an indication of the number of doses dispensed and/or an indication of the number of doses remaining. The indicator means comprises a ring (26) mounted for rotation about the aerosol vial, the ring having a plurality of circumferential teeth (28) which co-operate with a plurality of tines (30) mounted on the housing. During the reciprocatory motion of the aerosol vial when the valve is operated one or more of the tines (30) abuts a cam surface on one or more of the teeth (28) causing rotation of the ring (26) by a small increment. Suitable indication markings are present on the side of the ring (26) which may be viewed through a transparent window (32) in the housing to provide the patient with an indication of the contents remaining. Examples of such means for providing an indication of the contents of an inhaler are disclosed in our co-pending British Patent Application No. 8913893.7, dated 16th June, 1989. FIGS. 4 and 5 of the accompanying drawings illustrate the breath-actuated inhaler of FIGS. 1 to 3 positioned within a protective casing generally shown at (34). The casing comprises a body portion (36) and a movable cover (38). The protective casing completely envelopes the inhaler preventing ingress of dust and other contaminates and provides robust protection against percussion damage should the inhalation device be dropped etc. In the embodiment shown in FIGS. 4 and 5 the movable cover (38) is pivoted about pivot point (40) and has a forward protecting extension (39) which when closed fills the gap between pivot (40) and the casing. As the cover is pivoted, this extension (39) acts as a cam (42) on the bar of the inhaler and lifts it up against spring (48). After 90° of movement flange (44) is lifted above first step (45) on projection (46) on the protective cover and is retained on second step, where it remains during remainder of cover movement. On closing, the cover disengages flange (44) from step (45) and allows it to return to original position. Thus, a patient may simply open the cover of the casing and inhale through the mouthpiece to receive a dose of medicament. The breath-actuated inhaler is retained within the protective cover by a flange (44) on the housing engaging projection (46) on the interior of the protective cover. The inhaler may simply be removed by pushing the inhaler upwards against the cocking spring (48) until the flange (44) and projection (46) disengage and then the inhaler may be readily pulled from the protective casing. The breath-actuated inhaler may be inserted within the protective cover by fully opening the cover, pushing the top of the inhaler up against the cocking spring and inserting the base until the flange (44) engages the projection (46). When the cover is closed the breath-actuated inhaler will automatically be converted to the breath-actuated mode, even if it is in the press-and-breathe mode, by flange (25) on the cover pushing switch (22) to the breath-actuated position. It will be readily appreciated that the protective casing may be constructed in a number of different configurations and it is not necessary for the opening of the cover to automatically apply a cocking force to the inhaler. The arrangement of FIG. 6a and 6b comprises a body portion (36) and a cover (38) which is pivotally mounted about pivot point (40). Opening of the cover (38) does not apply a cocking force to the breath-actuated inhaler. Cocking lever (50) is provided at the top of the protective cover and is constructed and arranged such that upon pivoting the cocking lever (50) downward pressure is applied to the aerosol vial of the breath-actuated inhaler (FIG. 6b). FIGS. 7a and 7b illustrate an alternative form of protective casing comprising a body portion (36) and a movable cover (38) which is pivoted from a point at the top of the body portion and provides a cocking force to the inhaler as the cover (38) is opened. FIGS. 8a and 8b of the accompanying drawings illustrate a breath-actuated inhaler in accordance with the invention in which the protective casing (34) may be modified to accommodate aerosol vials of different length. The body portion (36) of the casing has an aperture (80) through which a shroud (82) extends which accommodates the aerosol vial (not shown). A series of shrouds (82) may be fabricated having different lengths in order to accommodate various sizes of aerosol vial. Whilst a cocking spring may be positioned within the top of the shroud (82), in a similar manner to the cocking spring (48 shown in FIG. 4), to absorb and retain the cocking force applied when the cover (38) is opened (as described with reference to FIG. 4) a cocking spring external of the shroud (82) may be employed. The shroud (82) is provided with a flange (84) and cocking spring (86) is positioned around the shroud (82) extending between the flange (84) and a stop or the top of the protective casing (88). When the cover (38) is opened, the breath-actuated inhaler, together with the shroud (82) is lifted (FIG. 8b) compressing cocking spring (86). When the patient breathes through the mouthpiece (4), the breath-actuated mechanism is triggered moving the shroud (82) and aerosol vial downwards to fire the aerosol valve. FIGS. 9a and 9b of the accompanying drawings illustrate an alternative cocking mechanism which may be incorporated into the protective casing of an inhalation device in accordance with the invention. The body portion (36) of the protective casing may comprise a separate upper portion (90) which envelopes the end of the aerosol valve (6). Cocking spring (48) is positioned within the upper portion of the casing (90) to act against the base of the aerosol vial (6). The upper portion (90) is retained on the body portion (36) of the protective casing by complimentary flanges (92 and 94) which constitute a thread segment such that rotation of the upper portion (90) in the direction of the arrow X (FIG. 9b) causes the upper portion (90) to move down the body portion (36) thereby compressing cocking spring (48) and applying the necessary cocking force for the breath-actuated mechanism. FIGS. 10a and 10b illustrate an inhalation device in accordance with the invention which incorporates the features of FIGS. 8 and 9. The top of the protective casing comprises an upper portion (90) through which extends a shroud (82) whose length is selected to accommodate the particular size of aerosol vial (6). Cocking spring (86) extends between flange (84) on the shroud and a stop or top (88) of the upper portion (90) and is compressed by downward movement of the upper portion (90) upon rotation in the direction of the arrow X. When the patient breathes through the mouthpiece (not shown) the breath-actuated device is triggered and the shroud (82) moves downwardly under the influence of the spring (86) thereby firing the aerosol valve. In a further embodiment of the invention (not illustrated in the drawings) the shroud (82) shown in FIGS. 8 and 10 may be dispensed with and replaced by a circumferential flange extending around the aerosol vial, equivalent to flange (84), against which cocking spring (86) will act. The circumferential flange may be fabricated as a snap-on component around the aerosol vial e.g., in the region of the neck of the vial. This arrangement will obviate the need for fabricating a series of shrouds to accommodate the different sizes of aerosol vial, since the aerosol vial will simply extend through the top of the protective casing.

An inhalation device comprising: (i) a breath-actuated inhaler comprising a medicament reservoir mounted within a housing which comprises a mouthpiece and breath-actuation means which prevents dispensing from the reservoir until a patient inhales through the mouthpiece, and, (ii) a protective casing surrounding the breath actuated inhaler, the casing comprising a body portion and a movable cover which may be displaced to allow a patient access to the mouthpiece to use the breath-actuated inhaler while it is within the casing, the breath-actuated inhaler being removable from the protective casing and operable outside the casing.

FIELD OF THE INVENTION The present invention relates to a laser printing system for forming images by scanning a photosensitive member with a laser beam for exposure. BACKGROUND OF THE INVENTION Electrophotographic printers having a laser as the light source generally include an optical device which comprises the laser light source, laser beam shaping means and a beam scanning assembly. In recent years, such printers have been required to have a dot density (DPI: dots/inch) in the range of 100 to 1000, whereas different dot densities need different optical devices, consequently necessitating different printers. Accordingly, Unexamined Japanese Patent Application No. SHO 59-117372 proposes a printer which is adapted to selectively give one of a plurality of different dot densities by automatically collectively controlling the laser beam diameter, laser modulation frequency, speed of rotation of a polygonal mirror for scanning with the beam and speed of rotation of the photosensitive drum. However, since the prior-art printer has a single optical device which has a variable beam diameter, laser modulation frequency and rotational speed of the polygonal mirror, the device is complex in construction and becomes large-sized. Moreover there is a limitation to the speed of the motor in varying the speed of the polygonal mirror, and a higher speed results in impaired durability and a lower speed involves uneven rotation. The use of one optical device thus imposes limitations on the range of dot density variations, so that there arises a need to prepare different printers for widely varying dot densities. SUMMARY OF THE INVENTION Accordingly, the primary object of the present invention is to provide a laser printing system having a wider range of dot density variations although the system is of the single printer type. Another object of the invention is to provide a laser printing system wherein the dot density is variable easily. Another object of the invention is to provide a laser printing system which is easy to repair when the laser optical device thereof malfunctions and which is also easy to maintain. Still another object of the invention is to provide a laser printing system which is adapted to produce prints in different colors each at a suitable dot density. The foregoing objects can be fulfilled by providing a laser printing system comprising: a main body including a photosensitive member; and an optical unit for forming an image on the photosensitive member by projecting a laser beam thereon, said unit being exchangably provided in said main body and being selected from a plurality of units each having a different dot density, and comprising; a laser beam source, means for driving the laser beam source, means for shaping the laser beam, means for scanning the surface of said photosensitive member with the laser beam, and means for giving an instruction as to the dot density of said unit to said main body; wherein said main body forms the image at the dot density according to the instruction corresponding to the selected optical unit. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects or features of the present invention will become apparent from the following description of preferred embodiments thereof taken in conjunction with the accompanying drawings, in which: FIGS. 1 and 2 are respectively a diagram and a perspective view schematically showing the construction of a laser printing system according to a first embodiment of the invention; FIG. 3 is a diagram showing the construction of an optical unit included int he first embodiment; FIG. 4 is a block diagram showing how the first embodiment is controlled; FIG. 5 is a block diagram showing how the form of modified from the first embodiment is controlled. FIG. 6 is a diagram showing the construction of a laser printing system according to a second embodiment of the invention; and FIG. 7 is a diagram showing the construction of a laser printing system according to a third embodiment of the invention. In the following description, like parts are designated by like reference numbers throughout the several drawings. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 are a diagram and a perspective view schematically showing the construction of the first embodiment, i.e., a laser printing system. The system per se is adapted for practicing a known electrophotographic process and has a photosensitive drum 1 disposed in its center and drivingly rotatable in the direction of arrow a. Arranged around the drum 1 are a sensitizing charger 2, a magnetic brush developing unit 3, a transfer charger 4, a cleaner 5 of the blade type and an eraser lamp 6. The surface of the drum 1 is first charged to a predetermined potential by the charger 2 and the irradiated with a laser beam from the optical unit 20 to be described below in detail to form an electrostatic latent image on the drum surface. The latent image is converted to a visible image by the deposition of tone by the developing unit 3. By the discharge of the transfer charger 4, the toner image is transferred onto copy paper fed from a paper cassette 10 through a path indicated by a two-dot-and-dash line and is thermally fixed to the paper by a fixing unit 11. The copy paper is thereafter delivered onto a discharge tray 12. On the other hand, the photosensitive drum 1 continues to rotate in the direction of arrow a after the image transfer, cleaned by the cleaner 5 for the removal of the residual toner, irradiated by the eraser lamp 6 for the removal of the residual charge and made ready for the subsequent copying cycle. The optical unit 20 is int he form of a cartridge having a case 21 with a handle 22 and can be removably installed in position within the main body of the system from the front side thereof by being guided along unillustrated guide rails or the like. The optical unit 20 has inside the case 21 a laser diode 25 serving as a light source, a collimator lens 26, a polygonal mirror 27, a drive motor 28 for rotating the mirror, SOS lens 29, reflecting mirror 30 and SOS sensor 31. The laser beam emitter by the laser diode 25 and spreading out to some extent is collimated by the collimator lens 26, deflected by the polygonal mirror 27 and projected via the fθ lens 29 and the reflecting mirror 30 onto the drum 1 parallel to the axis thereof, i.e., along the main scanning line L. The SOS sensor 31 has the function of correcting an error in the recording start position in each scan line due to the errors involved in the division of the mirror surface of the polygonal mirror 27. To detect the image start position in the main scanning direction, the sensor is position in equivalent relation to the main scanning line L on the surface of the photosensitive drum 1. With the above arrangement, the relationship between the dot density and various optical factors is represented by the following equations. It is herein assumed that the dot density in the main scanning direction is identical with that in the subscanning direction. Beam diameter (d): d-C.sub.1 /D (1) Number of revolutions (R) of the polygonal mirror: R=C.sub.2.D.V/N (2) Modulation frequency (f): f=C.sub.3.F.D.sub.2.V/N (3) Amount of light (E): E=C.sub.4.P.sub.0.N(F.V) (4) wherein C 1 -C 4 : proportional constant D: dot density V: peripheral speed of the drum N: number of polygonal mirror faces F: focal distance of the fθ lens P 0 : output of the laser diode The beam diameter (d) is determined from Equation (1) based on the dot density (D). In the optical unit 20, the beam diameter (d), for example, can be varied by using a different beam expander or prism or varying the focal distance of the collimator lens 26. According to the present embodiment, the dot density (D) is variable by changing the optical unit 20. Accordingly, different optical units 20 with different dot densities are prepared, such that when it is assumed that the peripheral speed V of the photosensitve drum is constant, all or one of the rotational speed (R) of the polygonal mirror, the number (N) of the polygonal mirror faces, the modulation frequency (f) and the focal distance (F) of the fθ lens in each optical unit 20 is altered in accordance with the dot density thereof. When the number of polygonal mirror faces, (N), is given, the number of revolutions (R) of the polygonal mirror is determined from Equation (2) according to the dot density (d). If the modulation frequency (f) is constant, Equation (3) gives the focal distance (F) of the fθ lens. Equation (4) reveals that at varying dot densities (D), the amount of light on the drum can be made constant by varying the laser output (P 0 ). On the other hand, Equation (3) indicates that when the modulation frequency (f) and the fθ lens focal distance (f) are constant, the dot density (D) can be varied by altering the number of polygonal mirror faces, (N). However, to obtain varying focal distances (F) or varying numbers of polygonal mirror faces, it is necessary to prepare a plurality of fθ lenses 29 or polygonal mirrors 27 in accordance with the dot densities of different optical units, at a greatly increased cost. Equations (2) and (3) show that the dot density (D) is readily variable by altering the number of revolutions (R) of the polygonal mirror and the modulation frequency (f) when the fθ lens focal distance (F) and the polygonal mirror face number (N) remain constant. Equation (2) indicates that the polygonal mirror speed (R) is proportional to the dot density (D). Equation (3) shows that the modulation frequency (f) is in proportion to the square of the dot density (D). The above description reveals that when optical units 20 with different dot densities are prepared, one of a plurality of different dot densities is selectively available simply changing the optical unit cartridge. For the different optical units 20 to provide varying dot densities (D), it is practically most feasible to vary the number of revolutions (R) of the polygonal mirror and the modulation frequency (f) as already described. With the present embodiment, the optical unit 20 includes an oscillation circuit 40 which comprises a basic clock circuit (clock signal generating circuit) 40a and a frequency divider circuit 40b for controlling the number of revolutions (R) of the polygonal mirror 27 and the modulation frequency (f) of the laser diode 25. More specifically stated with reference to FIG. 4, the oscillation circuit 40 feeds frequency data to a polygonal mirror drive circuit 41 within the optical unit 20 to drive the polygonal mirror motor 28 at a speed (R) predetermined for the particular unit 20 concerned. Further the oscillation circuit 40 feeds modulation frequency date (f) to image control means of a mechanical control circuit 43 provided int he system main body and including a microcomputer. In the image control means, the data is combined with image data from a character generator 44 to give LD data (pulse width and pulse on-off data), which is fed to the laser diode drive circuit 42, causing the laser diode 25 to emit a laser beam on modulation. On the other hand, the other signals to be given by the optical unit 20 to the mechanical control circuit 43 in the main body include a lock signal which is delivered from the drive circuit 41 when the speed of the polygonal mirror 27 has reach the predetermined value. and an SOS (synchronizing) signal which is produced from the SOS sensor 3 for determining the scanning start position. Also fed to the mechanical control circuit 43 is a paper size signal which is produced from a paper sensor 45 provided on the paper cassette 10 shown in FIGS. 1 and 2 for determining the image area. The basic clock circuit 40a may alternatively be provided in the mechanical control circuit 43 in the main body. Also usable as the beam scanning means in place of the polygonal mirror 27 are a galvanomirror, holographic scanner, etc. As already stated, the dot density (D) is variable by altering not only the polygonal mirror speed (R) but also the polygonal mirror face number (N). In other words, the desired dot density (D) can be obtained at a lower mirror speed (R) using a polygonal mirror having an increased number (N) of faces. Then a fall bearing is used, the mirror speed (R) is limited to about 10,000 r.p.m., and the permissible range is exceeded when the dot density (D) is higher than a certain level. In such a case, the speed (R) can be set within the permissible range of up to 10,000 r.p.m. by increasing the face number (N). As shown in FIG. 4, the optical unit 20 feeds the modulation frequency data (f) and the polygonal mirror rotation frequency data (R) to the mechanical control circuit 43 in the main body, and the dot density (D) of the optical unit 20 is transmitted to the main body in terms of these two items of data. Other dot density (D) indicating signals may alternatively be used. The dot density thus transmitted to the system main body serves to indicate the image area, in other words, the dot number for the specified paper size and the dot number from the scanning start point to the end point. The dot density indicating signal may be delivered via the mechanical control circuit 43 to the character generator 44 so as to produce a pattern in accordance with the dot density. Although the present embodiment has been described above based on the assumption that the dot density in the main scanning direction is identical with that in the subscanning direction, at least one of these do densities can be variable independently. Equations (1) to (3) can be interpreted as follows when the dot density (DM) in the main scanning direction and the dot density (DS) in the subscanning direction are considered separately. Beam diameter in main scanning direction (dM): dM=C.sub.5 /DM (5) Beam diameter in subscanning direction (dS): dS=C.sub.6 /DS (6) Number of revolutions (R) of polygonal mirror: R=C.sub.7.DS.V/N (7) Modulation frequency (f): f=C.sub.8.F.DM.DS.V/N=C.sub.9.F.DM.R (8) where C 5 -C 9 are proportional constants. The beam diameters (dM), (dS) in the main and subscanning directions are determined form Equations (5), (6) based on the dot densities (DM), (DS) in the main and subscanning directions, respectively. When the two beam diameters (dM), (dS) are different, the laser beam is elliptical in cross section. Equation (7) shows that the dot density (DS) in the subscanning direction is dependent on the polygonal mirror speed (R) and the polygonal mirror face number (N). It is herein assumed that the peripheral speed of the photosensitive drum is constant as in the foregoing case. Accordingly, the dot density (DS) in the subscanning direction is variable by altering the mirror speed (R) and/or the mirror face number (N). On the other hand, Equation (8) indicates that the dot density (DM) in the main scanning direction is dependent on the modulation frequency (f), the fθ lens focal distance (F) and the polygonal mirror face number (N). Accordingly, if the dot density (DS) in the subscanning direction is varied by altering the mirror speed (R), the dot density (DM) in the main scanning direction also will consequently be varied. The dot density (DS) can only be varied while keeping the other density (DM) at the specified value without any variation, by altering the modulation frequency (f) and/or the fθ lens focal distance (F). For example, the dot density (DS) in the subscanning direction only can be doubled by doubling the mirror speed (R) and also doubling the modulation frequency (f). The dot density (DM) in the main scanning direction then remains unchanged as will be apparent from Equation (8). Conversely, the dot density (DM) in the main scanning direction only can be varied, for example, by altering the modulation frequency (f) only. In this case, the dot density (DS) in the subscanning direction remains unchanged. It will be apparent from the above description that the dot densities (DM), (DS) in the main scanning and subscanning directions are also both variable independently of each other. With reference to FIG. 5, an exemplary circuit construction of optical unit 20 will be described below which is adapted to vary the dot densities (DM), (DS) in the main scanning and subscanning directions indepently of each other. Throughout FIGS. 4 and 5, like parts are designated by like reference numbers, and the difference only will be described. The construction of FIG. 5 comprises, in addition to the construction of FIG. 4, a polygonal mirror face number data generating circuit 47 disposed in the optical unit 20. The circuit 47 gives the mechanical control circuit 43 of the main body the data as to the polygonal mirror face number (N) of the optical unit 20. The mechanical control circuit 20 recognizes the dot density (DM) in the main scanning direction with reference to the data as to the number of revolutions of the polygonal mirror, (R), and the data as to the laser diode modulation frequency, (f), from the oscillation circuit. The circuit 20 further recognizes the dot density (DS) in the subscanning direction with reference to the polygonal mirror frequency data (f), the mirror face number data (N) and the drum peripheral speed data (V) stored in the circuit 20. In accordance with the two dot densities, the circuit 20 conducts communications with the character generator 44 to prepare the desired LD data. The dot densities in the main scanning direction and the subscanning direction are controllable independently of each other by the above construction. Data is handled, for example, according to the G3 standard of the facsimile system at densities of 8 pixels/mm in the main scanning direction and 3.85 lines/mm or 7.7 lines/mm in the subscanning direction. When optical units are prepared in conformity with these densities, output images can be produced by the present system for input data without the necessity of image edition. Further when an optical unit is used for main bodies which have a peripheral speed of he photosensitive drum, the main bodies will operate at the same dot density n the main scanning direction but differ in the dot density in the subscanning direction, consequently producing images which are enlarged or contracted in the subscanning direction. Such drawback can be overcome if each main body is equipped with a proper optical unit in conformity with the peripheral speed of its photosensitive drum. According to the first embodiment described above, cartridges having different dot densities are prepared, one of which is selectively used to obtain the desired one of the dot densities. This enables a single printing system to produce widely varying dot densities. The present system is further easy to maintain because a malfunction, if it occurs, can be remedied by merely replacing the faulty cartrige. A second embodiment of the invention will be described next. The second embodiment is adated to form images in more than one color by incorporating a plurality of optical units, as well as a plurality of electrophotographic image forming units, each identical with the corresponding unit of the first embodiment. FIG. 6 shows the second embodiment wherein electrophotographic units A and A' are arranged in series. In FIG. 6, the same parts as those of the first embodiment individually in corresponding relation are designated by the same corresponding reference numerals, and a prime is attached to each reference numeral for the second unit A'. Copy paper is transported in the direction of arrow c as indicated by a two-dot-and-dash line. The first photographic unit A transfers an image to the paper, and the second unit A' forms another image as superposed on the first image. With the second embodiment, optical units 20 and 20' are interchangeable and are each replaceable by an optical unit of different dot density. For example, suppose the first optical unit 20 has a dot density of 200 DPI, the first developing unit 3 contains a black toner, the second optical unit 20' has a dot density of 300 DPI, and the second developing unit 3' contains a red toner. Images of 200 DPI are then formed in black, and those of 300 DPI in red. For example, lines for which high resolution is required can be reproduced in red, and other characters in black, selectively. If the optical units 20, 20' are interchanged, images of 200 DPI will be formed in red, and those of 300 DPI in black. When another optical unit of a still different dot density (e.g., 400 DPI) is prepared and installed into the system as a replacement, images can be formed in black or red at this dot density. FIG. 7 is a diagram showing a third embodiment of the invention. The third embodiment comprises one photosensitive drum 1 and arranged around the drum 1 are a sensitizing charger 2, an optical unit 20 and a developing units 3 filled with a developer containing a color toner which are arranged in a first stage, and a sensitizing charger 2', an optical unit 20' and a developing unit 3' filled with a developer containing a black toner which are arranged in a second stage. Further arranged around the drum are a transfer charger 4, a cleaner 5 and an eraser lamp 6. With this embodiment, a first toner image is formed by the optical unit 20 and the developing unit 3, and the optical unit 20' and the developing unit 3' form another toner image superposed on the first image. The combined toner image is then transferred onto copy paper by a single transfer operation with the transfer charger 4. The optical units 20 and 20' of the third embodiment are the same as those of the second embodiment and therefore will not be described in detail. The third embodiment is equivalent tot he second embodiment in the result achieved. While the image forming elements for forming two-color images are arranged according to the above second and third embodiments, optical units which are identical or different in dot density may be arranged side by side for one set of image forming elements so as to selectively use one of the optical units. One of the optical units, when used more frequently than the other in this case, can be discarded and replaced by the less frequently used one, and a new optical unit installed in the latter position. Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.

A laser printing system including a main body having a photosensitive member and an optical unit for forming an image on the photosensitive member by projecting a laser beam thereon. The optical unit is detachably provided in said main body and has a laser beam source, a laser beam source drive circuit, a laser beam shaping member, and a polygonal mirror for scanning the surface of the photosensitive member with the laser beam. The optical unit gives to the main body an instruction as to the dot density especially assigned thereto. The main body forms the image at the dot density assigned to the optical unit which is selected from a plurality of optical units having different dot densities. Accordingly, the optical units having different dot densities are prepared so as to be selectively used to obtain the desired one of the dot densities.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation of International Application No. PCT/EP2004/005052, filed May 12, 2004, the entire disclosure whereof is expressly incorporated by reference herein, which claims priority of German Patent Application No. 103 30 971.3, filed Jul. 8, 2003. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a skin or wound contact material or pad with wound healing promoter substances and/or skin care substances which are present in encapsulated form in the material and which controllably deliver the substance only with contact with the wound secretion or moisture. [0004] 2. Discussion of Background Information [0005] Correct pharmaceutical formulation of physiological actives is one of the principal tasks of the pharmaceutics in the drug industry. Thus the actual active substance in the pharmaceutical formulation often accounts for only a small part of the overall formula, alongside numerous physiologically inactive excipients. However, it is these very excipients via which release location and release kinetics of an active substance in the body can be modified so as to produce optimum development of the desired action. For instance, acid-resistant capsules can be used to ensure that active substances pass through the acidic stomach before being released in a targeted manner in the alkaline environment of the intestine; delayed-release formulations utilize the diffusion-controlled release of the active substance from the pharmaceutical in order to make the active substance available at pharmacologically active concentrations over a prolonged period (in this regard see also K. H. Bauer, K-H. Frömming, C. Führer in “Pharmazeutische Technologie”, 5th edition 1997). [0006] Skin injuries and wounds pose an interesting challenge to the development of suitable formulations of wound healing promoter substances, since not only the high level of metabolic activity in the wound but also the steady secretion of wound fluid ensure a continuously changing wound milieu. Formulations with wound healing promoter substances and disinfectant substances are known in particular on the basis of liquid formulas or ointments and must be applied a number of times a day for optimum development of action. [0007] Treating wounds with wound plasters and wound dressings has the aim, primarily, of preventing mechanical penetration of foreign bodies and microorganisms and of creating a wound milieu in which optimum conditions prevail for the healing process of the skin. [0008] Modern wound care products such as hydrocolloids (in this regard see, for example, “Hydrokolloide” by R. Lipmann in Medical Device & Diagnostic Industry, June 1999), which were developed for colostomy applications and occupational wound care applications, are finding application increasingly. [0009] Wound care products based on hydrocolloids have advantages over conventional plasters. They generate a moist wound healing environment, which does not let the wound dry out and produces an optimum environment for rapid wound healing. Further advantages are the inconspicuousness in application, secure adhesion, absorption capacity for exudate, effective cushioning, and painless removability. [0010] Contoured wound contact materials with an adhesive layer composed of swellable hydrocolloids and water-insoluble viscous constituents, examples being polyisobutylene, rubber, silicon or polyurethane elastomers, are subject matter of WO 92/05755. [0011] Water-free hydrogels are referred to as xerogels and are macromolecular, natural or synthetic substances which by virtue of a high level of hydrophilic groups are capable of binding water absorptively. The water absorption capacity of many xerogels is a multiple of the intrinsic weight of the water-free substance. Hydrogels or xerogels are employed in diverse form in wound care, since they protect wounds against drying out, draw up wound secretion, and serve as a matrix for active substances of all kinds and also as a basis for population with autologous or heterologous skin cells. [0012] One form in which gels can be used is that of foams. Foams for treating skin wounds or surgical wounds are known per se to the skilled worker. In this context use is made predominantly of polyurethane foams or collagen foams. [0013] Self-adhesive gel foams as well are known to the skilled worker. Although these foams generally attach very well to the skin, in the majority of cases they have the drawback that their water absorption capacity and water retention capacity are severely restricted. [0014] Furthermore, hydrophilic foams of polyurethane gels are known. WO 88/01878 A1 describes self-adhesive polyurethane foams or polyurethane foam gels which can include, among other monomer units, copolymerized methacrylates. These foam gels are produced by adding water. [0015] Polyurethane gels based on a polyurethane matrix and relatively high molecular mass polyols are also described in EP 0 057 839 B1. Self-attaching sheet-like structures comprising polyurethane gels are known from EP 0 147 588 B1. The polyurethane gels disclosed in these two last-mentioned texts are unfoamed. The self-adhesive gels have isocyanate indexes of 15 to 70 (EP 0 147 588 A2). [0016] EP 0 196 364 A2 describes hydrophilic polyurethane foams which may be filled with water-absorbing polymers based on a copolymer of acrylic acid and potassium acetate and are intended for medical use. The polyurethane is prepared on the basis of MDI, methylenediphenyl diisocyanate. The polyether used has a minimum functionality of two hydroxyl groups, preferably two to three hydroxyl groups in each case. The NCO/OH ratio is stoichiometric. The polyurethane is accordingly not gel-like. Foaming can be carried out using pressurized air or using other gases which do not react with the isocyanate, or by means of low-boiling solvents. Water-absorbing polymer and polyether polyol are mixed in a ratio of about 3:1, serving for water absorption. The foam has adhesive properties on wounds, which have to be eliminated completely by means of an aluminized web in order that the foam may be used for wound treatment. The water-absorbing polymers disclosed in EP 0 196 364 A2 are not doped with actives. [0017] Foam wound contact materials composed of a polyurethane gel foam comprising a polyaddition product of a polyether polyol (Levagel®, Bayer AG) with an aromatic or aliphatic diisocyanate (Desmoder®, Bayer AG), into which a polyacrylate superabsorbant powder (Favor®, Stockhausen) has been incorporated, are described inter alia in DE 42 33 289 A1, in DE 196 18 825 A1, and WO 97/43328. Depending on the ratio of OH equivalents in the polyol to reactive isocyanate groups, the polyurethane gel may be formulated for weak or strong self-attachment to skin. [0018] It is known that the incorporation of water-absorbing polymers into the reactive precursors of a polyurethane reaction allows the preparation of polyurethane-based wound contact materials which have excellent skin compatibility and also a high capacity to absorb fluid. The moist wound milieu promoted by wound contact materials of this kind contributes to a considerable acceleration in wound healing. In none of the prior art publications, however, are absorbents doped with wound healing promoter actives or with skin care substances disclosed in polycondensate matrices, especially polyurethane matrices. [0019] Furthermore, active substance patch systems in the form of transdermal therapeutic systems (TTS) for delivering active substances through the skin have been known for a long time. The topical application of drugs by way of active substance patch systems offers two main advantages: First, this form of administration produces first-order release kinetics of the active substance, thereby enabling a constant level of active substance to be maintained in the body over a fairly long time period. Secondly, the path of uptake through the skin avoids the gastrointestinal tract and also the first liver passage. As a result, selected drugs may be effectively administered in a low dose. This is particularly advantageous when the drug is desired to act locally while avoiding a systemic effect. This is the case, for example, with the treatment of rheumatic joint complaints or muscular inflammation. [0020] One embodiment of such transdermal systems which has been well described in the technical literature is that of matrix systems or monolithic systems, in which the drug is incorporated directly into the pressure-sensitive adhesive. In the ready-to-apply product, a pressure-sensitively adhesive matrix comprising active substance of this kind is equipped on one side with a backing impermeable to the active substance, while on the opposite side there is a backing film equipped with a release layer, which is removed prior to application to the skin (kleben&dichten, No. 42, 1998, pp. 26 to 30). For instance, the use of polyacrylates and/or polyurethanes is mentioned principally as a basis for the pressure-sensitively adhesive polymer matrix (Lamba, Woodhouse, Cooper, “Polyurethanes in Biomedical Applications”, CRC Press, 1998, p. 240) and WO 01/68060. [0021] A problem associated with the production of transdermal therapeutic systems is the introduction of polar active substances into the usually nonpolar polymer matrices. As a result, preferred active substances may occasionally be incorporated with difficulty or in limited concentration into the polymer matrix. Furthermore, there is a risk, owing to the difference in polarity and the insolubility of the active substances in the polymer matrix, that the active substances will crystallize out of the polymer system over time. Long-term stability is hence not always guaranteed. [0022] With regard to the incorporation of different wound healing promoter substances or skin care substances into matrices, especially polyurethane matrices, the problem exists, furthermore, that many of these substances also undergo reaction with polar functional groups, such as dexpanthenol, for example, in the crosslinking reaction of the polyurethane. As a result, on the one hand, there is disruptive crosslinking of the matrix, and on the other hand the active substance is also incorporated covalently into the matrix, and can no longer be released from it. Consequently it is impossible to incorporate these active substances into the matrix prior to the crosslinking reaction. It is therefore necessary to introduce these substances into the polyurethane matrix in costly and inconvenient downstream operations. This is disruptive not only for the production step. [0023] Known from the prior art, furthermore, are a series of documents which disclose water-absorbing polymers doped with active substance. For instance, US 2003/0004479 describes a water-absorbing composition composed of a water-absorbing polymer and a plant powder active, the water-absorbing polymer being post-crosslinked in the surface region. [0024] It would be desirable to be able to provide a skin or wound contact material capable of absorbing moisture, especially water, and of delivering a wound healing promoter and/or skin care active. It would hence also be desirable to be able to provide a contact material capable of caring for human skin, increasing its resistance and/or healing a wound. [0025] It would in particular be desirable to provide a wound dressing capable of absorbing wound exudate that is adequately able to draw up moisture from the skin and, where appropriate, to transport it outward through the plaster, that generates a moist wound healing environment, that is skin-compatible, that is painlessly redetachable, and that comprises wound healing promoter and/or skin care adjuvants which can be delivered in a controlled way over a prolonged time period. [0026] It would further be desirable to provide a contact material which through the addition of wound healing promoter substances and/or skin care substances does not exert any influence on the possibly self-adhesive properties of the contact material, and which is simple and inexpensive to produce. SUMMARY OF THE INVENTION [0027] The present invention provides skin or wound contact material which comprises a polycondensate matrix and a water-absorbing polymer incorporated therein. The water-absorbing polymer is doped with a wound healing promoter substance and/or a skin care substance. [0028] In one aspect of the material, at least a part of the water-absorbing polymer may be covalently bonded to the polycondensate matrix. [0029] In another aspect, the polycondensate matrix may be air and water vapor permeable and/or self-adhesive and/or transparent. [0030] In yet another aspect, the polycondensate matrix may comprise a polyurethane matrix. By way of non-limiting example, the polyurethane matrix may be formed from (a) one or more polyether polyols having from 2 to 6 hydroxyl groups, OH numbers of from 20 to 112, and an ethylene oxide content of at least 10% by weight, (b) one or more antioxidants, (c) a catalyst comprising one or more bismuth(III) carboxylates which are based on carboxylic acids having from 2 to 18 carbon atoms and are soluble in the polyols (a), and (d) hexamethylene diisocyanate. [0035] In one aspect of the above polyurethane matrix, the product of the functionalities of components (a) and (d) may be at least 5.2 and the ratio of free NCO groups of component (d) to free OH-groups of component (a) may be from 0.30 to 0.70 and/or component (c) may be present in an amount of from 0.005% to 0.25% by weight and/or component (b) may be present in an amount of from 0.1% to 1.0% by weight, each based on component (a). [0036] In another aspect of the material of the present invention, the water-absorbing polymer may be present in particulate form. [0037] In yet another aspect of the material, the water-absorbing polymer may comprise at least 50% by weight, e.g., at least 70% by weight, or at least 90% by weight, of one or more carboxylate group containing monomers. [0038] In a still further aspect of the above material, the water-absorbing polymer may comprise at least 50% by weight of acrylic acid, and at least 20 mol %, e.g., at least 50 mol %, and preferably from 65 to 85 mol % of the acrylic acid may be neutralized. [0039] In another aspect, the water-absorbing polymer may comprise crosslinked sodium polyacrylate. [0040] In another aspect of the material of the material of the present invention, the water-absorbing polymer may exhibit one or more of the following properties: A1) a particle size distribution wherein at least 80% by weight of particles have a size of from 10 μm to 900 μm, determined according to ERT 420.1-99; A2) a centrifuge retention capacity (CRC) of at least 10 g/g, e.g., at least 20 g/g, determined according to ERT 441.1-99; A3) an absorption against pressure (AAP) at 0.7 psi of at least 4 g/g, determined according to ERT 442-1-99; A4) a water-soluble polymer content after a 16 hour extraction of less than 25% by weight, based on the total weight of the water-absorbing polymer, determined according ERT 470.1-99; A5) a residual moisture content of not more than 15% by weight, based on the total weight of the water-absorbing polymer, determined according ERT 430.1-99. [0046] In yet another aspect of the material of the present invention, the water-absorbing polymer may exhibit at a particle size distribution of from 10 μm to 500 μm and/or a residual moisture content of less than 10% by weight, e.g., less than 3% by weight. [0047] In a still further aspect of the material, the wound healing promoter substance and/or skin care substance may be present in an amount of from 0.001% to 30% by weight, e.g., from 5% to 15% by weight, based on the total weight of the water-absorbing polymer plus the wound healing promoter substance and/or skin care substance. [0048] In another aspect, the wound healing promoter substance and/or skin care substance may be present in an amount of from 0.1% to 10.0% by weight, e.g., from 0.2% to 5% by weight, based on the weight of the matrix. [0049] In another aspect of the material, the wound healing promoter substance and/or skin care substance may be distributed, preferably homogeneously, over the entire water-absorbing polymer. [0050] In yet another aspect of the material, the water-absorbing polymer may be present in an amount of from 70% to 99.99% by weight, based on the total weight of the water-absorbing polymer and the wound healing promoter substance and/or skin care substance, the water-absorbing polymer may comprise at least 90% by weight of a crosslinked polyacrylic acid, based on the water-absorbing polymer, and the crosslinked polyacrylic acid may comprise at least 90% by weight, based on the crosslinked polyacrylic acid, of acrylic acid which may comprise at least 30 mol % of partially neutralized acrylic acid. [0051] In a still further aspect of the material, the wound healing promoter substance and/or skin care substance may exhibit an availability of at least 10% by weight, determined according to the extraction test described hereinafter. [0052] In yet another aspect of the material of the present invention, the wound healing promoter substance and/or skin care substance may comprise one or more of dexpanthenol, marigold, witch hazel, camomile, a vitamin, an antioxidant, a light stabilizer, an insect repellent, an essential oil, an antimicrobial agent, a moisturizer, a perfume and coenzyme Q10, preferably at least dexpanthenol and/or coenzyme Q10. [0053] The present invention also provides a skin or wound contact material which comprises a self-adhesive, air and water vapor permeable polyurethane matrix and a water-absorbing polymer incorporated therein. The water-absorbing polymer comprises at least 50% by weight of one or more carboxylate group containing monomers and is doped with a wound healing promoter substance and/or a skin care substance. [0054] In one aspect of the material, at least a part of the water-absorbing polymer may be covalently bonded to the polyurethane matrix and/or the water-absorbing polymer may be present in particulate form. [0055] In another aspect, the water-absorbing polymer may comprise at least 50% by weight of acrylic acid and from 65 to 85 mol % of the acrylic acid may be neutralized. [0056] In yet another aspect, the water-absorbing polymer may exhibit a particle size distribution of from 10 μm to 500 μm and/or a residual moisture content of less than 3% by weight. [0057] In a still further aspect, the wound healing promoter substance and/or skin care substance may comprise at least one of dexpanthenol, marigold, witch hazel, camomile, a vitamin, an antioxidant, a light stabilizer, an insect repellent, an essential oil, an antimicrobial agent, a moisturizer and coenzyme Q10. [0058] In yet another aspect of the materials of the present invention, the materials may further comprise a backing sheet. For example, the matrix may be applied in foamed or unfoamed form, partially or over the whole area, to the backing sheet. By way of non-limiting example, the backing sheet may comprise at least one of a polyurethane, a polyethylene, a polypropylene, a polyamide, a polyester and a polyether-ester. [0059] In another aspect, the materials may further comprise a liner sheet and/or a liner paper and/or a release paper. [0060] In another aspect, the materials of the present invention may be comprised in a wound dressing, a bandage or a plaster, or they may be comprised in a dry or moist cosmetic wipe or a pad. [0061] The present invention also provides a process for producing a skin or wound contact material which comprises a polyurethane matrix and a water-absorbing polymer which has a wound healing promoter substance and/or a skin care substance incorporated therein. The process comprises reacting a mixture comprising a polyether polyol and an aliphatic isocyanate prepolymer and adding a water-absorbing polymer doped with the wound healing promoter substance and/or skin care substance to form the polyurethane matrix having the water-absorbing polymer incorporated therein. [0062] In one aspect, the process may further comprise the subsequent coating of the polyurethane matrix having the water-absorbing polymer incorporated therein two-dimensionally onto a backing sheet. [0063] It was surprising, and unforeseeable for the skilled worker, that a skin or wound contact material comprising a. a polycondensate matrix, preferably a polyurethane matrix, based on at least one polycondensable monomer having at least one polycondensable group, and b. a particulate, water-absorbing polymer comprising at least one wound healing promoter substance and/or at least one skin care substance which has at least one functional group that is able to react with the polycondensable group and forms a covalent bond with the polycondensable group, or [0066] c. a water-absorbing polymer comprising at least one wound healing promoter substance and/or at least one skin care substance, [0000] the particulate, water-absorbing polymer being at least partly surrounded by the polycondensate matrix, [0000] at least the particulate, water-absorbing polymer comprising the wound healing and/or skin care substance, and [0000] the skin or wound contact material exhibiting a wound-healing substance or active substance availability of at least 10% by weight by the extraction test indicated herein achieves the above objects. [0067] In particular, a skin or wound contact material comprising an air and water vapor permeable, preferably self-adhesive polyurethane matrix comprising a water-absorbing polymer into which at least one wound healing promoter substance and/or at least one skin care substance, also referred to below as active substance, is incorporated achieves the stated objects and remedies the disadvantages of the prior art. [0068] By “water-absorbing” is meant in accordance with the invention not only the capacity of a substance to take up water into itself, with formation of a hydrogel, but also any absorption of aqueous fluids, especially aqueous body fluids such as urine, blood, blood constituents such as pus, lymph fluids or blood serum. [0069] Polycondensates used in accordance with the invention are preferably polyurethanes. In general, polyurethanes are prepared from the known starting compounds of polyurethane chemistry by known processes, which are set forth in DE-A 3103499 , DE-A 3103500 , EP 0 147 588 A1, EP 0 665 856 B1 or DE 196 18 825 A1. [0070] Polyurethane is used as a basis for the active substance matrix. The polyurethane (c) is prepared by polymerizing an alcohol (a) with an isocyanate (b). [0071] A decisive advantage of the polyurethane polymer or gel matrices are their self-adhesive properties, which make it unnecessary additionally to apply an adhesive layer to the matrix in order to attach the wound dressing in the region of the skin. At its most simple the active substance polyurethane matrix is located between a cover layer firmly anchored to it, also dubbed backing layer, and a removable release layer. [0072] The purpose of the removable release layer is to secure the adhesive layer and to improve stability in transit and on storage, and it is removed prior to application to the skin. [0073] The polyurethane matrix may be applied to a backing layer or backing sheet of the kind known from the prior art. The backing sheet is composed of an air and water vapor permeable but water impermeable polymer layer having a thickness of approximately 10 to 100 μm. The backing sheet, flexible under certain circumstances, is composed preferably of polymers of polyurethane, PE, PP, polyamide, polyester or polyether-ester. [0074] Suitable polyurethane matrices are subject matter of DE 196 18 825, which discloses hydrophilic, self-adhesive polyurethane gels composed of a) polyether polyols having from 2 to 6 hydroxyl groups, OH numbers of from 20 to 112, and an ethylene oxide (EO) content of >10% by weight, b) antioxidants, c) bismuth (III) carboxylates soluble in the polyols (a) and based on carboxylic acids having from 2 to 18 carbon atoms, as catalysts, and d) hexamethylene diisocyanate, with a product of the functionalities of the polyurethane-forming components a) and d) of at least 5.2, the amount of catalyst c) being from 0.005% to 0.25% by weight, based on the polyol a), the amount of antioxidants b) being in the range from 0.1% to 1.0% by weight, based on polyol a), and the selected ratio of free NCO groups of component d) to the free OH— groups of component a) (isocyanate index) being in the range from 0.30 to 0.70. [0079] It is preferred to use polyether polyols having 3 to 4, very preferably 4 hydroxyl groups, with an OH number in the range from 20 to 112, preferably from 30 to 56. The ethylene oxide content of the polyether polyols employed in accordance with the invention is preferably ≧20% by weight. [0080] The polyether polyols as such are known per se and are prepared for example by polymerizing epoxides, such as ethylene oxide, propylene oxide, butylene oxide or tetrahydrofuran, with themselves or by addition reaction of these epoxides, preferably of ethylene oxide and propylene oxide, where appropriate in a mixture with one another or separately in succession, with starter components having at least two reactive hydrogen atoms, such as water, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol, sorbitol or sucrose. Representatives of the stated high molecular mass polyhydroxyl compounds for use are listed for example in High Polymers, vol. XVI, “Polyurethanes, Chemistry and Technology” (Saunders-Frisch, Interscience Publishers, New York, vol. 1, 1962, pp. 32-42). [0081] As an isocyanate component use may be made of monomeric or trimerized hexamethylene diisocyanate or of hexamethylene diisocyanate modified by biuret, uretdione or allophanate groups or by prepolymerizing with polyether polyols or with mixtures of polyether polyols based on the known starter components having 2 to >2 reactive H atoms and epoxides, such as ethylene oxide or propylene oxide with an OH number of ≦850, preferably from 100 to 600. Preference is given to using modified hexamethylene diisocyanate, especially hexamethylene diisocyanate modified by prepolymerization with polyether diols of OH number from 200 to 600. Very particular preference is given to modifications of hexamethylene diisocyanate with polyether diols with an OH number of 200-600 whose residual monomeric hexamethylene diisocyanate content is below 0.5% by weight. [0082] Catalysts suitable for the polyurethane gels of the invention are bismuth (III) carboxylates soluble in the anhydrous polyether polyols a) and based on linear, branched, saturated or unsaturated carboxylic acids having from 2 to 18, preferably from 6 to 18, C atoms. Preference is given to Bi(III) salts of branched saturated carboxylic acids having tertiary carboxyl groups, such as of 2,2-dimethyloctanic acid (for example, Versatic acids, Shell). Highly suitable preparations are preparations of these Bi(III) salts in excess fractions of these carboxylic acids. A system which has been found outstandingly appropriate is a solution of 1 mol of the Bi(III) salt of Versatic 10 acid (2,2-dimethyloctanic acid) in an excess of 3 mol of this acid having a Bi content of about 17%. [0083] The catalysts are used preferably in amounts of from 0.03% to 0.3% by weight, based on the polyol a). [0084] Suitable antioxidants for the polyurethane gels of the invention are, in particular, sterically hindered phenolic stabilizers, such as BHT (2,6-di-tert-butyl-4-methylphenol), Vulkanox BKF (2,2 min methylene-bis-(6-tert-butyl-4-methylphenol) (Bayer AG), Irganox 1010 (pentaerythrityl tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenol)propionate]), Irganox 1076 (octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenol)propionate) (Ciba-Geigy) or tocopherol (vitamin E). Preference is given to using those of the α-tocopherol type. The antioxidants are used preferably in amounts of from 0.15 to 0.5% by weight, based on the polyol a). [0085] The isocyanate index (ratio of the free NCO groups used in the reaction to the free OH groups) of the polyurethane gel compositions of the invention is in the range from 0.30 to 0.70, preferably in the range from 0.45 to 0.60, depending on the functionality of the isocyanate components and polyol components employed. The isocyanate index required for gel formation can be estimated very simply by the following formula: f ( polyol ) · ( f ( isocyanate ) - 1 ) · Index ≈ 2 Index ≈ 2 f ( polyol ) * ( f ( isocyanate ) - 1 ) f: functionality of isocyanate or polyol component [0086] Depending on the target tackiness or elasticity of the gel, the isocyanate index to be actually used may differ by up to ±20% from the calculated value. [0087] The polyurethane gel compositions of the invention are produced by customary processes such as are described for example in Becker/Braun, Kunststoff-Handbuch, vol. 7, Polyurethane, p. 121 if, Carl-Hauser, 1983. [0088] With further preference polyurethane gels are employed as are disclosed in EP 0 665 856 B1. The hydrophilic polyurethanes are obtainable accordingly from [0000] 1. a polyurethane gel which comprises [0000] (A) 25-62%, preferably 30-60%, more preferably 40-57%, by weight based on the sum of (A) and (B), of a covalently crosslinked polyurethane as a high molecular weight matrix and (B) 75-38%, preferably 70-40%, more preferably 60-43%, by weight based on the sum of (A) and (B), of one or more polyhydroxyl group compounds which are firmly held in the matrix by secondary valence forces and have an average molecular weight of between 1000 and 12 000, preferably between 1500 and 8000, more preferably between 2000 and 6000, and an average OH number of between 20 and 112, preferably between 25 and 84, more preferably between 28 and 56, as a liquid dispersant, the dispersant being substantially free of hydroxyl compounds having a molecular weight of below 800, preferably below 1000, more preferably below 1500, and also, if desired (C) 0 to 100% by weight, based on the sum of (A) and (B), of fillers and/or additives, and which is obtainable by reacting a mixture of a) one or more polyisocyanates b) one or more polyhydroxyl compounds having an average molecular weight of between 1000 and 12 000 and an average OH number of between 20 and 112, c) if desired, catalysts or accelerators for the reaction between isocyanate groups and hydroxyl groups, and also, if desired, d) fillers and additives known per se from polyurethane chemistry, this mixture being substantially free of hydroxyl compounds having a molecular weight below 800, the average functionality of the polyisocyanates (F i ) being between 2 and 4, the average functionality of the polyhydroxyl compound (F p ) being between 3 and 6, and the isocyanate index (K) conforming to the formula K = 300 ± X ( F i · F p ) - 1 + 7 in which X is ≦120, preferably X is ≦100, more preferably X is ≦90, and the index K is at values between 15 and 70, the stated molecular weight and OH number averages being number averages, 2. a water-absorbing material and/or 3. a nonaqueous foaming agent. [0096] With regard to the preparation of preferably self-adhesive polyurethane it should be borne in mind that the above-defined conditions are complied with when the gel-forming components are selected, since otherwise tack-free elastic gels rather than self-adhesive gels are obtained. [0097] Preferred hydroxyl compounds are polyether polyols as specified at length in the abovementioned laid-open specifications. [0098] Suitable polyisocyanate components include not only (cyclo)aliphatic but also aromatic isocyanates. Preferred (cyclo)aliphatic polyisocyanates are 1,6-hexamethylene diisocyanate and also its biurets and trimers and hydrogenated diphenylmethane diisocyanate (“MDI”) grades. Preferred aromatic polyisocyanates are those which are obtained by distillation, such as MDI mixtures of 4,4′ and 2,4′-isomers or 4,4′-MDI, and also toluene diisocyanate (“TDI”) grades. [0099] The diisocyanates may be selected in particular, for example, from the group of the unmodified aromatic or aliphatic diisocyanates or else from modified products formed by prepolymerization with amines or polyols, including polyether polyols. [0100] As advantages of the polyurethanes of the invention in comparison to other polycondensates and polymers, used in particular for the production of dressing materials, the following points may be cited: Polyurethane can be provided flexibly as a self-adhesive or nonadhesive matrix. As a self-adhesive system it is possible to dispense with addition of further adhesives, which under certain circumstances give rise to side effects such as maceration, inflammation of the dermal areas, reduction of cutaneous respiration, etc. Polyurethanes prove extremely advantageous over other adhesive materials, such as polyacrylates, rubber, etc., since they constitute no allergenic potential. Polyurethane exhibits very good water vapor permeability. This ensures that, in the case of application for a prolonged period, there is no maceration through the release of water by the skin. The oxygen permeability of polyurethane ensures a good supply of oxygen to the covered skin site, thereby countering damage to the tissue. Polyurethane is allergenically neutral, so that following application there is no likelihood of allergic reactions by the body. In contrast to other materials such as hydrocolloids or hydrogels, for example, polyurethane, moreover, shows no tendency to disintegrate on prolonged contact with fluids such as wound exudate. Consequently, on prolonged contact with wound fluid, a wound dressing produced from polyurethane does not leave residues in the wound that interfere with further wound healing. Self-adhesive polyurethane disbonds on contact with fluid, so that sticking to newly formed tissue is prevented and, moreover, painless detachment of the wound cover is ensured. Polyurethane wound contact materials of the invention produce a moist wound milieu, leading to more rapid wound healing. [0110] The polymer matrix, preferably the polyurethane matrix, may be used with no foaming and/or with partial or full-area foaming, with no filling or with additional fillers, such as, for example, titanium dioxide, zinc oxide, plasticizers, dyes, etc. [0111] Foaming of the matrix allows an improved cushioning effect to be achieved and, together with this an improved tactile sensation for the user. [0112] The matrix, in particular the polyurethane polymer, may optionally comprise additives known per se from polyurethane chemistry, such as, for example, fillers and short, organic- or inorganic-based fibers, metal pigments, surface-active substances or liquid extenders such as substances having a boiling point of more than 150° C. [0113] Examples of inorganic fillers that may be mentioned include heavy spar, chalk, gypsum, kieserite, sodium carbonate, titanium dioxide, cerium oxide, quartz sand, kaolin, carbon black and polar microspheres. [0114] Organic fillers which can be used include, for example, powders based on polystyrene, polyvinyl chloride, urea-formaldehyde and polyhydrazodicarbonamide. Suitable short fibers include, for example, glass fibers 0.1-1 mm in length or fibers of organic origin, such as polyester fibers or polyamide fibers, for example. Metal powders, such as iron, aluminum, or copper powder, for example, may likewise be used in the context of gel formation. In order to give the gels the desired coloration it is possible to use the organic- or inorganic-based color pigments or dyes which are known per se in connection with the coloring of polyurethanes, such as, for example, iron oxide pigments or chromium oxide pigments, phthalocyanine-based or monoazo-based pigments. Surface-active substances include, for example, cellulose powders, activated carbon, and silica products. [0115] To modify the adhesive properties of the gels it is possible where appropriate to make additions of polymeric vinyl compounds, polyacrylates, and other copolymers customary in adhesive technology, and/or adhesives based on natural substances, in an amount of up to 10% by weight, based on the weight of the gel composition, without altering the advantageous properties of the polyurethanes. [0116] The polymer matrix can advantageously be made transparent. As transparent, water vapor permeable, and adhesive, the matrix thus fulfills esthetic and application-friendly aspects. This represents a significant advantageous difference from the polyacylate- and silicon gel-based plaster systems. Moreover, the transparency increases user acceptance, since the skin or wound contact materials of the invention, particularly in the form of patches or plasters, can be worn on the skin typically for a longer time period. [0117] If the contact material of the invention is self-adhesive there is no need for additional fixing means. The wound contact material is placed directly as a dressing material on the wound to be covered, and by virtue of its self-adhesive properties adheres to the skin surrounding the wound. [0118] In the case of sizeable wounds, if additional adhesive bonding is desired, or if the polymer matrix is not self-adhesive, the wound contact material can be adhered to the skin by the addition of an edge layer bonding system. [0119] In that case the dressing material of the invention is constructed in accordance with known wound dressings. They are composed, generally speaking, of a backing material provided on one side with a self-adhesive layer. The wound contact material of the invention is then applied to this self-adhesive coating. In order to ensure ease of handling, a self-adhesive coating is additionally lined with a protective layer—a sealing paper, for example. [0120] A suitable adhesive for the edge layer bonding system over the additional backing material is set out in DE 27 43 979 C3; in addition, the acrylate-based or rubber-based pressure-sensitive adhesives that are commercially customary can be used with preference for the adhesive coating. [0121] Particular preference is given to thermoplastic hot-melt adhesives based on natural and synthetic rubbers and on other synthetic polymers such as acrylates, methacrylates, polyurethanes, polyolefins, polyvinyl derivatives, polyesters or silicones with appropriate adjuvants such as tackifier resins, plasticizers, stabilizers, and other auxiliaries where appropriate. If desired, post-crosslinking by UV or electron beam irradiation may be appropriate. [0122] Hot-melt adhesives based on block copolymers, in particular, are distinguished by their multifarious possibilities for variation, since through the controlled reduction in the glass transition temperature of the self-adhesive composition, by virtue of the selection of the tackifiers, the plasticizers, and the polymer molecule size, and the molecular distribution of the components employed, the necessary functional bonding with the skin is ensured even at critical locations of the human locomotor apparatus. [0123] The high shear strength of the hot-melt adhesive is achieved through the high cohesiveness of the polymer. The good tack results from the range of tackifiers and plasticizers that is employed. [0124] The adhesive preferably includes at least one aromatic component with a fraction of less than 35%, preferably 5% to 30%. [0125] For particularly strongly adhering systems the hot-melt adhesive is based preferably on block copolymers, especially A-B or A-B-A block copolymers or mixtures thereof. The hard phase A is principally polystyrene or its derivatives, and the soft phase B comprises ethylene, propylene, butylene, butadiene, isoprene or mixtures thereof, more preferably ethylene and butylene or mixtures thereof. [0126] The controlled blending of di-block and tri-block copolymers is particularly advantageous, and in this case a di-block copolymer fraction of less than 80% by weight is preferred. [0127] In one advantageous version the hot-melt adhesive has the composition indicated below: 10% to 90% by weight of block copolymers 5% to 80% by weight of tackifiers such as oils, waxes, resins and/or mixtures thereof, preferably mixtures of resins and oils, less than 60% by weight of plasticizers, less than 15% by weight of additives, less than 5% by weight of stabilizers. [0128] The aliphatic or aromatic oils, waxes and resins serving as tackifiers are preferably hydrocarbon oils, waxes and resins, the consistency of the oils, such as paraffinic hydrocarbon oils, or of the waxes, such as paraffinic hydrocarbon waxes, having a favorable effect on bonding to the skin. Plasticizers used are medium- or long-chain fatty acids and/or their esters. These additions serve to set the adhesive properties and the stability. If desired, further stabilizers and other auxiliaries are employed. [0129] The backing materials are composed preferably of an air and water vapor permeable but water impermeable polymer layer having a thickness of approximately 10 to 100 μm. The backing sheet, which is flexible in certain circumstances, is composed preferably of polymers of polyurethane, PE, PP, polyamide, polyester or polyether ester or of known backing materials such as wovens, nonwovens, foams, plastics, etc. [0130] The polyurethane matrix of the invention may be applied atop this backing layer or backing sheet, in the way which is known from the prior art. In that case the matrix is lined on one side with the backing material and applied as a composite sheet. Depending on the backing material used it is possible by this means to control the water vapor permeability, the strength of the wound cover, the cushioning against pressure, and other physical qualities of the wound cover. [0131] An inventively furnished dressing material, with or without additional edge bonding system, is then placed on the wound in customary fashion. [0132] The direct introduction of numerous wound healing promoter substances and/or skincare substances into the matrix, in particular into the polymer matrix, is not possible prior to the crosslinking reaction thereof, since these substances possess active hydrogen atoms (hydroxyl, amino or acid groups) which would co-react in the crosslinking reaction, during polyurethane formation for example. The consequences would be an under-crosslinked matrix and covalently bonded actives no longer available for wound healing or skin care. [0133] This problem can be remedied in accordance with the invention by introducing the wound healing promoter or skin care actives into the reaction mixture in encapsulated form at the same time removing them from the crosslinking reaction. [0134] For this purpose the substances are bound in or encapsulated by means of water-absorbing polymers, such as superabsorbers, for example, this being referred to collectively also as incorporation. [0135] Superabsorbers in which active or other substances such as dexpanthenol, for example, are in encapsulated form are, by way of example, crosslinked sodium polyacrylates of the kind known, for example, as Favor T®. They are composed of a crosslinked polyacrylate matrix in which, depending on its type, the active substance in question has been introduced into the matrix before or after the polymerization and can be released again from said matrix only in a swelling operation. These products can be incorporated into the non-crosslinked polyurethane matrix base materials prior to reaction, without inhibiting the crosslinking reaction of the polyurethane matrix. The active-doped superabsorber only then releases the active from the crosslinked matrix during application, i.e. on contact with aqueous media, such as the wound exudate, for example, over a relatively long time period and, with advantage, constantly. [0136] With regard to the skin or wound contact materials of the invention it is preferred for the water-absorbing polymer to comprise [0137] (α1) from 0.1% to 99.999%, preferably from 20% to 98.99%, and more preferably from 30% to 98.95% by weight of polymerized ethylenically unsaturated, acid-functional monomers or salts thereof, or polymerized, ethylenically unsaturated monomers containing a protonated or quaternized nitrogen, or mixtures thereof, particular preference being given to mixtures comprising at least ethylenically unsaturated, acid-functional monomers, preferably acrylic acid, [0000] (α2) 0 to 70%, preferably from 1% to 60%, and more preferably from 1% to 40% by weight of polymerized, ethylenically unsaturated monomers copolymerizable with (α1), [0000] (α3) from 0.001% to 10%, preferably from 0.01% to 7%, and more preferably from 0.05% to 5% by weight of one or more crosslinkers, [0000] (α4) 0 to 30%, preferably from 1% to 20%, and more preferably from 5% to 10% by weight of water-soluble polymers, and [0000] (α5) 0 to 20%, preferably from 0.01% to 7%, and more preferably from 0.05% to 5% by weight of one or more auxiliaries, the sum of the amounts by weight of (α1) to (α5) being 100% by weight. [0138] The monoethylenically unsaturated, acid-functional monomers (α1) may be partly or fully neutralized, preferably partly neutralized. The degree of neutralization of the monoethylenically unsaturated, acid-functional monomers is preferably at least 25 mol %, more preferably at least 50 mol %, and with further preference 50-90 mol %. The monomers (α1) may be neutralized before and also after the polymerization. Furthermore, neutralization may take place with alkali metal hydroxides, alkaline earth metal hydroxides, ammonia, and carbonates and bicarbonates. In addition to these, any other base which forms a water-soluble salt with the acid is conceivable. Also conceivable is mixed neutralization with different bases. Preference is given to neutralization with ammonia or with alkali metal hydroxides, more preferably with sodium hydroxide or with ammonia. [0139] Preferred monoethylenically unsaturated, acid-functional monomers (α1) are acrylic acid, methacrylic acid, ethacrylic acid, α-chloroacrylic acid, α-cyanoacrylic acid, β-methylacrylic acid (crotonic acid), α-phenylacrylic acid, β-acryloyloxypropionic acid, sorbic acid, α-chlorosorbic acid, 2′-methylisocrotonic acid, cinnamic acid, p-chlorocinnamic acid, p-stearylic acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, aconitic acid, maleic acid, fumaric acid, tricarboxyethylene, and maleic anhydride, acrylic acid and methacrylic acid being particularly preferred and acrylic acid being even more preferred. [0140] Besides these carboxylate-functional monomers, preferred monoethylenically unsaturated, acid-functional monomers (α1) further include ethylenically unsaturated sulfonic acid monomers or ethylenically unsaturated phosphonic acid monomers. [0141] Ethylenically unsaturated sulfonic acid monomers are allylsulfonic acid or aliphatic or aromatic vinylsulfonic acids or acrylic or methacrylic sulfonic acids. Preferred aliphatic or aromatic vinylsulfonic acids are vinylsulfonic acid, 4-vinylbenzylsulfonic acid, vinyltoluenesulfonic acid, and styrenesulfonic acid. Acrylic and methacrylicsulfonic acids are sulfoethyl (meth)acrylate, sulfopropyl (meth)acrylate, and 2-hydroxy-3-methacryloyloxypropylsulfonic acid. A preferred (meth)acrylamido alkylsulfonic acid is 2-acrylamido-2-methylpropanesulfonic acid. [0142] Preference is further given to ethylenically unsaturated phosphonic acid monomers, such as vinylphosphonic acid, allylphosphonic acid, vinylbenzylphosphonic acid, (meth)acrylamido alkylphosphonic acids, acrylamido alkyldiphosphonic acids, phosphonomethylated vinylamines, and (meth)acrylophosphonic acid derivatives. [0143] According to the present invention it is preferred for the water-absorbing polymer to be composed of at least 50% by weight, preferably at least 70% by weight, and more preferably at least 90% by weight of monomers containing carboxylate groups. It is particularly preferred in accordance with the invention for the water-absorbing polymer to be composed of at least 50% by weight, preferably at least 70% by weight, of acrylic acid, which is neutralized preferably to at least 20 mol %, more preferably to at least 50 mol %, and with further preference in the range from 65 to 85 mol %, preferably with sodium hydroxide solution. [0144] As ethylenically unsaturated monomers (α1) containing a protonated nitrogen preference is given preferably to dialkylaminoalkyl (meth)acrylates in protonated form, examples being dimethylaminoethyl (meth)acrylate hydrochloride or dimethylaminoethyl (meth)acrylate hydrosulfate, and also to dialkylaminoalkyl(meth)acrylamides in protonated form, examples being dimethylaminoethyl(meth)acrylamide hydrochloride, dimethylaminopropyl-(meth)acrylamide hydrochloride, dimethylaminopropyl(meth)acrylamide hydrosulfate or dimethylaminoethyl)(meth)acrylamide hydrosulfate. [0145] Preferred ethylenically unsaturated monomers (α1) containing a quaternized nitrogen are dialkylammonioalkyl (meth)acrylate in quaternized form, examples being trimethylammonioethyl (meth)acrylate methosulfate or dimethylethylammonioethyl (meth)acrylate ethosulfate, and also (meth)acrylamidoalkyldialkylamines in quaternized form, examples being (meth)acrylamidopropyltrimethylammonium chloride, trimethylammonioethyl (meth)acrylate chloride or (meth)acrylamido-propyltrimethylammonium sulfate. [0146] Preferred monoethylenically unsaturated monomers (α2) which can be copolymerized with (α1) are acrylamides and methacrylamides. [0147] Possible (meth)acrylamides, beside acrylamide and methacrylamide, include alkyl-substituted (meth)acrylamides or aminoalkyl-substituted derivatives of (meth)acrylamide, such as N-methylol(meth)acrylamide, N,N-dimethylamino-(meth)acrylamide, dimethyl(meth)acrylamide or diethyl(meth)acrylamide. Examples of possible vinyl amides are N-vinyl amides, N-vinylformamides, N-vinylacetamides, N-vinyl-N-methylacetamides, N-vinyl-N-methylformamides and vinylpyrrolidone. Particularly preferred among these monomers is acrylamide. [0148] Further preferred monoethylenically unsaturated monomers (α2) which can be copolymerized with (α1) are water-dispersible monomers. Preferred water-dispersible monomers are acrylic esters and methacrylic esters, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate or butyl (meth)acrylate, and also vinyl acetate, styrene and isobutylene. [0149] Crosslinkers (α3) which are preferred according to the present invention include compounds having at least two ethylenically unsaturated groups within one molecule (crosslinker class I), compounds having at least two functional groups which are able to react with functional groups of the monomers (α1) or (α 2 ) in a condensation reaction (=condensation crosslinkers), in an addition reaction or in a ring-opening reaction (crosslinker class II), compounds which contain at least one ethylenically unsaturated group and at least one functional group which is able to react with functional groups of the monomers (α1) and (α2) in a condensation reaction, in an addition reaction or in a ring-opening reaction (crosslinker class II), or polyvalent metal cations (crosslinker class IV). The compounds of crosslinker class I produce crosslinking of the polymers through the free-radical polymerization of the ethylenically unsaturated groups of the crosslinker molecule with the monoethylenically unsaturated monomers (α1) or (α2), whereas in the case of the compounds of crosslinker class II and the polyvalent metal cations of crosslinker class IV the crosslinking of the polymers is achieved through condensation reaction of the functional groups (crosslinker class II) or by electrostatic interaction of the polyvalent metal cation (crosslinker class IV) with the functional groups of the monomers (α1) or (α2). In the case of the compounds of crosslinker class III, accordingly, crosslinking of the polymer takes place both by free-radical polymerization of the ethylenically unsaturated groups and by condensation reaction between functional groups of the crosslinker and the functional groups of the monomers (α1) or (α2). [0150] Preferred compounds of crosslinker class I are poly(meth)acrylic esters which are obtained, for example, by the reaction of a polyol, such as ethylene glycol, propylene glycol, trimethylolpropane, 1,6-hexanediol, glycerol, pentaerythritol, polyethylene glycol or polypropylene glycol, for example, of an amino alcohol, of a polyalkylene polyamine, such as diethylentriamine or triethylenetetraamine, for example, or of an alkoxylated polyol with acrylic acid or methacrylic acid. Preferred compounds of crosslinker class I further include polyvinyl compounds, poly(meth)allyl compounds, (meth)acrylic esters of a monovinyl compound or (meth)acrylic esters of a mono(meth)allyl compound, preferably of the mono(meth)allyl compounds of a polyol or of an amino alcohol. Attention is drawn in this context to DE 195 43 366 and DE 195 43 368. The disclosures thereof are hereby incorporated by reference and are therefore considered part of the present disclosure. [0151] Examples of compounds of crosslinker class I include alkenyl di(meth)acrylates, examples being ethylene glycol di(meth)acrylate, 1,3-propylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 1,18-octadecanediol di(meth)acrylate, cyclopentanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, methylene di(meth)acrylate or pentaerythritol di(meth)acrylate, alkenyl di(meth)acrylamides, examples being N-methyl di(meth)acrylamide, N,N′-3-methylbutylidenebis(meth)acrylamide, N,N′-(1,2-dihydroxyethylene)bis(meth)acryl-amide, N,N′-hexamethylenebis(meth)acrylamide or N,N′-methylenebis(meth)-acrylamide, polyalkoxy di(meth)acrylates, examples being diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate or tetrapropylene glycol di(meth)acrylate, bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, benzylidine di(meth)acrylate, 1,3-di(meth)acryloyloxypropan-2-ol, hydroquinone di(meth)acrylate, di(meth)acrylate esters of trimethylolpropane alkoxylated, preferably ethoxylated, with 1 to 30 mol of alkylene oxide per hydroxyl group, thioethylene glycol di(meth)acrylate, thiopropylene glycol di(meth)acrylate, thiopolyethylene glycol di(meth)acrylate, tiopolypropylene glycol di(meth)acrylate, divinyl ethers, for example, 1,4-butanediol divinyl ether, divinyl esters, for example, divinyl adipate, alkane dienes, for example, butadiene or 1,6-hexadiene, divinylbenzene, di(meth)allyl compounds, for example, di(meth)allyl phthalate or di(meth)allyl succinate, homopolymers and copolymers of di(meth)allyldimethylammonium chloride and homopolymers and copolymers of diethyl(meth)allylaminomethyl(meth)acrylate ammonium chloride, vinyl-(meth)acrylic compounds, examples being vinyl (meth)acrylate, (meth)allyl(meth)acrylic compounds, examples being (meth)allyl (meth)acrylate, (meth)allyl (meth)acrylate ethoxylated with 1 to 30 mol of ethylene oxide per hydroxyl group, di(meth)allyl esters of polycarboxylic acids, examples being di(meth)allyl maleate, di(meth)allyl fumarate, di(meth)allyl succinate or di(meth)allyl terephthalate, compounds having 3 or more ethylenically unsaturated, free-radically polymerizable groups such as, for example, glycerol tri(meth)acrylate, (meth)acrylate esters of glycerol ethoxylated with preferably 1 to 30 mol of ethylene oxide per hydroxyl group, trimethylolpropane tri(meth)acrylate, tri(meth)acrylate esters of trimethylolpropane alkoxylated, preferably ethoxylated, with preferably 1 to 30 mol of alkylene oxide per hydroxyl group, trimethacrylamide, (meth)allylidene di(meth)acrylate, 3-allyloxy-1,2-propanediol di(meth)acrylate, tri(meth)allyl cyanurate, tri(meth)allyl isocyanurate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, (meth)acrylic esters of pentaerythritol ethoxylated preferably with 1 to 30 mol of ethylene oxide per hydroxyl group, tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate, trivinyl trimellitate, tri(meth)allylamine, di(meth)allylalkylamines, for example, di(meth)allylmethylamine, tri(meth)allyl phosphate, tetra(meth)allyl-ethylenediamine, poly(meth)allyl esters, tetra(meth)allyloxyethane or tetra(meth)allyl-ammonium halides. Preferred according to the present invention in crosslinker class I are vinyl isocyanates, trivinyl trimellitate or tri(meth)allyl isocyanurate, with trivinyl trimellitate being particularly preferred. [0152] Preferred compounds of crosslinker class II are compounds having at least two functional groups which are able to react in a condensation reaction (=condensation crosslinkers), in an addition reaction or in a ring-opening reaction with the functional groups of monomers (α1) or (α2), preferably with acid groups of the monomers (α1). These functional groups of the compounds of crosslinker class II are preferably alcohol, amine, aldehyde, glycidyl, isocyanate, carbonate or epichloro functions. [0153] Examples of compounds of crosslinker class II include polyols, examples being ethylene glycol, polyethylene glycols, such as diethylene glycol, triethylene glycol, and tetraethylene glycol, propylene glycol, propylene glycols such as dipropylene glycol, tripropylene glycol or tetrapropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2,4-pentanediol, 1,6-hexanediol, 2,5-hexanediol, glycerol, polyglycerol, trimethylolpropane, polyoxypropylene, oxyethylene-oxypropylene block copolymers, sorbitan fatty acid esters, polyoxyethylenesorbitan fatty acid esters, pentaerythritol, polyvinyl alcohol and sorbitol, amino alcohols, examples being ethanolamine, diethanolamine, triethanolamine or propanolamine, polyamine compounds, examples being ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or pentaethylenehexamine, polyglycidyl ether compounds such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, hexanediol glycidyl ether, trimethololpropane polyglycidyl ether, sorbitol polyglycidyl ether, phthalic acid diglycidyl ester, adipic acid diglycidyl ether, 1,4-phenylenebis(2-oxazoline), glycidol, polyisocyanates, preferably diisocyanates such as toluene 2,4-diisocyanate and hexamethylene diisocyanate, polyazridine compounds such as 2,2-bishydroxymethylbutanol tris[3-(1-aziridinyl)propionate], 1,6-hexamethylenediethyleneurea, and diphenylmethane bis-4,4′-N-N′-diethyleneurea, halogen epoxides, examples being epichlorohydrin and epibromohydrin and α-methylepichlorohydrin, alkylene carbonates such as 1,3-dioxolan-2-one (ethylene carbonate), 4-methyl-1,3-dioxolan-2-one (propylene carbonate), 4,5-dimethyl-1,3-dioxolan-2-one, 4,4-dimethyl-1,3-dioxolan-2-one, 4-ethyl-1,3-dioxolan-2-one, 4-hydroxymethyl-1,3-dioxolan-2-one, 1,3-dioxan-2-one, 4-methyl-1,3-dioxan-2-one, 4,6-dimethyl-1,3-dioxan-2-one, 1,3-dioxolan-2-one, poly-1,3-dioxolan-2-one, and polyquaternary amines such as condensation products of dimethylamines and epichlorohydrin. Further preferred compounds of crosslinker class II are polyoxazolines such as 1,2-ethylenebisoxazoline, crosslinkers with silane groups, such as γ-glycidoxypropyltrimethoxysilane and γ-amino-propyltri-methoxysilane, oxazolidinones such as 2-oxazolidinone, bis- and poly-2-oxazolidinones and diglycol silicates. [0154] Preferred compounds of class III are hydroxyl or amino containing esters of (meth)acrylic acid, such as 2-hydroxyethyl (meth)acrylate for example, and also hydroxyl or amino containing (meth)acrylamides, or mono(meth)allyl compounds of diols. [0155] The polyvalent metal cations of crosslinker class IV are derived preferably from monovalent or polyvalent cations, the monovalent ones in particular from alkali metals, such as potassium, sodium or lithium, preference being given to lithium. Preferred divalent cations derive from zinc, beryllium, alkaline earth metals, such as magnesium, calcium or strontium, preference being given to magnesium. Higher polyvalent cations which can be used further in accordance with the invention are cations of aluminum, iron, chromium, manganese, titanium, zirconium, and other transition metals, and also double salts of such cations or mixtures of the stated salts. It is preferred to use aluminum salts and alums and their various hydrates such as, for example, AlCl 3 ×6H 2 O, NaAl(SO 4 ) 2 ×12H 2 O, KAl(SO 4 ) 2 ×12H 2 O or Al 2 (SO 4 ) 3 ×14-18H 2 O. [0156] With particular preference Al 2 (SO 4 ) 3 and its hydrates are used as crosslinkers of crosslinking class IV. [0157] Preference is given to water-absorbing polymers crosslinked by crosslinkers of the following crosslinker classes or by crosslinkers of the following combinations of crosslinker classes: I, II, III, IV, I II, I III, I IV, I II III, I II IV, I III IV, II III IV, II IV or III IV. The above combinations of crosslinker classes each constitute one preferred embodiment of crosslinkers of a water-absorbing polymer. [0158] Corresponding to a further preferred embodiment are water-absorbing polymers crosslinked by any one of the abovementioned crosslinkers of crosslinker classes 1 . Preferred among these are water-soluble crosslinkers. In this context, N,N′-methylenebisacrylamide, polyethylene glycol di(meth)acrylates, triallylmethylammonium chloride, tetraallylammonium chloride, and allyl nonaethylene glycol acrylate prepared with 9 mol of ethylene oxide per mole of acrylic acid, are particularly preferred. [0159] As water-soluble polymers (α4) it is possible for water-soluble addition polymers, such as partly or fully saponified polyvinyl alcohol, polyvinylpyrrolidone, starch or starch derivatives, polyglycols or polyacrylic acid to be present, preferably in copolymerized form, in the absorbing polymers of the invention. The molecular weight of these polymers is not critical, provided they are water-soluble. Preferred water-soluble polymers are starch or starch derivatives or polyvinyl alcohol. The water-soluble polymers, preferably synthetic ones such as polyvinyl alcohol, may also serve as a graft base for the monomers to be polymerized. [0160] Auxiliaries (α5) employed are preferably standardizers, odor binders, surface-active agents or antioxidants. [0161] From the aforementioned monomers and crosslinkers it is possible to prepare the water-absorbing polymer by a variety of modes of polymerization, which are known to the skilled worker. [0162] Typical processes are described in the following patents: U.S. Pat. No. 4,286,082, DE 27 06 135, U.S. Pat. No. 4,076,663, DE 35 03 458, DE 40 20 780 , DE 42 44 548, DE 43 23 001, DE 43 33 056 and DE 44 18 818. The disclosures thereof are hereby incorporated reference and are therefore considered part of the present disclosure. In the case of the abovementioned types of polymerization it is preferred to introduce the wound healing substance actually together with the monomer or monomers or solvent or solvents employed in the corresponding polymerization processes, as a mixture, into the polymerization in the variants already described above. [0163] By “wound healing substance” is meant in accordance with the invention, preferably, a substance or a mixture of substances, said substance, or at least one substance of said mixture, containing as a functional group a double bond, an OH group, an NH group or a COOH group, or a salt of at least one of these groups, preferably an OH group. It is preferred, moreover, for the wound healing substance to have from 2 to 100 carbon atoms and one to 20 oxygen atoms. The above properties are likewise preferred for the active substances or active drug substances of the invention. [0164] Generally speaking, wound healing substances used that are based on plant extracts are Equisetum arvense, Aloe barbadensis, Arnica Montana, Arnica chamissonis, Symphytum officinale, Solanum dulcamara, Echinacea pallida, Potentilla erecta, Trigonella foenumgraecum, Juglans regia, Linum usitatissimum, Terminalia sericea, Oenothera biennis, Centella asiatica, Arctium lappa, Capsella bursa - pastoris, Hypericum perforatum, Matricaria recutita, Chamomille recutita, Agrimonia eupatoria, Centaurea cyanus, Larrea tridentate, Populus spec,. Echinacea pupurea, Calendula officinalis, Aesculus hippocastanum, Salvia officinalis, Plantago lanceolata, Quercus robur, Glycyrhiza glabra, Quercus petraea, Hamamelis virgian, Cardiospermum halicacabum, Betula, Urtica dioica, Buxus chinensis, Lavandula angustifolia, Lavandula hybrida, Crocus sativus, Smilax aspera, Melaleuca alternifolia , amino acids or Viola tricolor or the salts thereof or derivatives or mixtures of at least two thereof, in accordance with the invention. [0165] Further suitable, additional wound healing substances or skin care agents are vitamins and the like, such as glucosamine sulfate, allantoin, biotin, chondroitin sulfate, coenzyme Q10, dexpanthenol, honey/honey extract, niacinamide, propolis, vitamin A or its esters, vitamin C and its esters, vitamin E and its esters or the salts thereof or derivatives or mixtures of at least two thereof, in accordance with the invention. [0166] Wound healing substances are preferably, in accordance with the invention, dexpanthenol or extracts of marigold, preferably calendula oil; or witch hazel, preferably D-hamelose; or of camomile, preferably camomile blossom oil—preferably bisabolol or azulene—or mixtures of at least two of all of the above substances. [0167] It is further preferred for in each case one of the above wound healing substances to be able to be present as the main component in a mixture, this main component being able to be present preferably at at least 50% by weight, more preferably at least 70% by weight, and very preferably at least 95% by weight, based in each case on the mixture. [0168] Skin care substances chosen are preferably vitamins, antioxidants, photo protectants, insect repellants, essential oils, antimicrobial agents, moisturizers, perfumes, and, in particular, coenzyme Q10. [0169] The wound healing promoter and/or skin care substances, which may be used individually or as a mixture, are included advantageously at from 0.1 to 10.0% by weight, preferably from 0.2% to 5% by weight, based on the polymer matrix, or at from 0.001 to 30% by weight, preferably from 5% to 15% by weight, based on the active-doped, water-absorbing polymer. [0170] The incorporation of the wound healing or skin care substance into the water-absorbing polymer before the end of the formation, or before the beginning of the polymerization of the water-absorbing polymer may take place by means of the following process steps. On the one hand, the substance can be incorporated into the water-absorbing polymer via the solvent used for preparing the water-absorbing polymer. On the other, the substance can be added to the monomer, oligomer or prepolymer, or at least two thereof, that is or are used to form the water-absorbing polymer. In both of the above variants the wound healing or skin care substance may be in the form of a solution, emulsion or suspension. Furthermore, the two above variants can be combined with one another. [0171] In another embodiment of the process of the invention the substance is incorporated after the end of the formation of the water-absorbing polymer or during its further processing, or both. This incorporation takes place preferably into a gel of the water-absorbing polymer. In that case it is preferred for the gel to have a water quantity, based on the water-absorbing polymer, of from 0.2 to 20 times, preferably from 1 to 10 times, and more preferably from 2 to 4 times, in order to achieve very highly uniform incorporation of the wound healing substance. [0172] This can be achieved on the one hand by absorption of the substance by means of a liquid, generally aqueous, vehicle, in which the substance is preferably in solution. In the case of incorporation of the wound healing or skin care substance in the course of further processing it is preferred for the substance to be incorporated in a liquid, preferably aqueous, phase into the water-absorbing polymer, where appropriate during the “post-crosslinking”. [0173] Combinations of the above process variants are also possible. In the case of incorporation of the substance before the end of the formation of the water-absorbing polymer, a uniform doping of the water-absorbing polymer is preferably achieved; in other words, advantageously, the substance is present homogeneously distributed in the polymer. If the substance is incorporated after the end of the formation of the water-absorbing polymer or during its further processing, or both, then preferably the doping of the water-absorbing polymer particle in its outer or surface region is like that illustrated in FIG. 2 . Combining the two process variants leads, as a general rule, to a polymer having a different concentration in the inner and outer regions of the water-absorbing polymer particle, the concentration of wound healing or skin care substance generally being higher in the outer region. [0174] The water-absorbing polymer thus obtained, doped with the substance, and referred to from now on as “doped or incorporated polymer”, can be incorporated subsequently into the polymer matrix, preferably into the polyurethane matrix. It is preferred for the doped polymer to be incorporated into the polycondensate matrix before the end of its formation, in other words before substantially all of the reactive functional groups of a polyurethane matrix monomer have been consumed by reaction. This is accomplished preferably by being able to add the doped polymer to the polyol needed for the formation of the polyurethane matrix. [0175] The wound dressing of the invention allows the skilled worker, therefore, for the first time to supply the active substances right at the beginning of the polyurethane formation reaction. This offers him or her great advantages in respect of breadth of variation and amount of active substances employed, and increases the flexibility associated with the production of the wound dressings. [0176] A wound dressing having the desired properties is obtained, for example, by coating out flatly a mixture of the following ingredients, crosslinked by means of an appropriate catalyst: Polyether polyol 334 g  Crosslinker 29 g Superabsorber doped with 10% 37 g wound healing substance (e.g., dexpanthenol) Catalyst 0.8 g  [0177] If the wound dressing thus obtainable is applied to a wound, the wound fluid causes the water-absorbing polymer to swell. The wound fluid is taken up by the polyurethane matrix and the water-absorbing polymers present therein. In contact with the fluid, said polymers begin to swell. As a result of this swelling process, the wound healing promoter substance or substances is or are released into the water-absorbing polymers. This allows direct release of the active substance at the wound treatment site. [0178] This is an exceptionally good application advantage, which allows an “intelligent bandage” to be produced, that releases the requisite active wound healing promoter substance only on contact with wound fluid. [0179] The kinetics of the release can be controlled on the one hand by the concentration of wound healing promoter substance in the water-absorbing polymer and on the other hand via the concentration of water-absorbing polymer in the polyurethane matrix. The release is further influenced by the distribution of the substance in the water-absorbing polymer ( FIG. 2 ). The distribution of the active substance in the water-absorbing polymer takes place in accordance with the invention, as described above, as a function of the time of addition before, after or during the end of the formation of the water-absorbing polymer. Preference is given to a wound dressing where the active substance is distributed, preferably homogeneously, throughout the water-absorbing polymer ( FIG. 2 , Version I). [0180] Consequently, solely by way of dry storage, a wound dressing ready for use is available for the user, which as well as the known advantages of hydroactive polyurethane wound dressings develops its wound healing promoter effect only where the latter is needed. [0181] Furthermore, the production method, the incorporation of the active substances via encapsulation in the superabsorber, is what makes it actually possible for the direct incorporation of wound healing promoter substances into the polyurethane matrix prior to its formation reaction. Only as a result of this is it at all possible to realize product structures which are doped homogeneously with active substances and whose shaping takes place during the crosslinking reaction. [0182] It is further preferred for the water-absorbing polymer of the wound dressing to have at least one of the following properties: A1) a particle size distribution with at least 80% by weight of the particles possessing a size in a range from 10 μm to 900 μm, as determined by ERT420.1-99; A2) a centrifuge retention capacity (CRC) of at least 10 g/g, preferably at least 20 g/g, determined by ERT441.1-99; A3) an absorption against pressure (AAP) at 0.7 psi of at least 4 g/g, determined by ERT442.1-99; A4) a water-soluble polymer content after a 16 hour extraction of less than 25% by weight, based in each case on the total weight of the water-absorbing polymer, determined by ERT470.1-99; A5) a residual moisture content of not more than 15% by weight, based in each case on the total weight of the water-absorbing polymer, determined by ERT430.1-99, the stated measurement methods for particle size determination being known. [0188] Mention may be made, by way of example, of the following parameters for characterizing the wound contact material when 10% superabsorber is added: adhesiveness: rheological characterization 0.20 of the viscoelastic properties tanδ (ω = 0.3 rad/s): fluid management: fluid uptake: 10 g/100 cm 2 water vapor permeability: 250 g/(m 2 × 24 h) O 2 permeability: 2000 cm 3 /(m 2 × 24 h) [0189] The above-mentioned properties can be determined using the test methods below. [0190] ERT [0191] Unless described otherwise below, ERT methods are used for determining the various properties pertaining to the water-absorbing polymer. ERT stands for EDANA recommended test, with EDANA standing for European Nonwoven and Diaper Association. [0192] Extraction Test [0193] 0.5 g of an active-doped sample—for example, a partially neutralized polyacrylic acid with a low degree of crosslinking, containing dexpanthenol as active, or a polyurethane matrix comprising it, is weighed out into a 125 ml wide-neck bottle on an analytical balance. Following the addition of 100 ml of a 0.9% strength solution of common salt (based on distilled water) and one drop of concentrated phosphoric acid, the mixture is stirred at 350 revolutions per minute on a magnetic stirrer for an hour. Then 2 ml of the solution are withdrawn and filtered through a 0.45 μm mixed cellulose ester membrane filter into a sample vial. The filtrate is then passed to an HPLC analysis, the sample used in the HPLC analysis having an acid pH in the region of 2.5 to 3.0. [0194] The amount of active is ascertained from the results of the HPLC analysis, using external calibration. For that purpose the active under determination is weighed in an amount of at least 10 mg to an accuracy of 0.1 mg, using an analytical balance, into a measuring flask with a capacity of 100 ml. The measuring flask is then filled to the mark with ultrapure water. Corresponding to the concentration of the resultant stock solution, a dilution series is then produced on the analytical balance. This dilution series is used to compile a calibration plot by means of HPLC analyses. The amount of active extracted over an hour is determined by comparing the HPLC analysis results for the active in question with the calibration plot. [0195] The chromatographic conditions are optimized as a function of the active under determination. In the case of dexpanthenol the column used may be a GromSil 300 ODS-5 5 μm (250×4 mm) column. The eluent is prepared by weighing out 13.61 g of KH 2 PO 4 into a glass beaker with a capacity of 3 l and carrying out dissolution following the addition of 2000 ml of ultrapure water. Concentrated phosphoric acid is then used to set a pH of 2.5 to 3.0. In the case of dexpanthenol the flow rate set is 0.8 ml/min. Injection takes place via a 20 μl loop. [0196] Rheological Characterization [0197] A sample with a diameter of 8 mm is punched out centrally from a bandage and is preconditioned at 23±2° C. and 50±5% rh for an hour. The sample is adhered centrally to an 8 mm rotating plate and measured on a shearing stress-controlled rheometer with a Peltier element for thermal conditioning (e.g., RS-75 from Haake). For that purpose the sample is pressed onto the bottom plate with a standard force of 1.3 N. After conditioning for 5 minutes at 25±0.2° C., the viscoelastic properties (storage modulus and loss modulus) are determined in the frequency range from φ=0.3 to 30 rad/s with a shearing stress of 700 Pa. The tanδ is calculated from the ratio of loss modulus to storage modulus. [0198] Fluid Absorption [0199] A sample with a diameter of 15 mm is punched out centrally from a bandage and preconditioned at 23±2° C. and 50±5% rh for an hour. The samples are weighed and immersed fully for 3 hours in physiological sodium chloride solution which has a temperature of 23±0.5° C. The samples are weighed again and the fluid absorption is calculated from the weight difference. [0200] Water Vapor Permeability [0201] The test is carried out in accordance with ASTM E 96 (water method), with the following differences: [0202] The opening of the test vessel is 804 mm 2 . [0203] The material is preconditioned for 24 hours at 23±2° C. and 50±5% rh. [0204] The distance between the water level in the test vessel and the sample is 35±5 mm. [0205] The reweighing of the test vessels complete with samples is carried out after 24 hours, during which they are stored in a controlled-climate cabinet at 37±1.5° C. and 30±3% rh. [0206] O2 Permeability [0207] Test in accordance with ASTM D3985-8. [0208] It is further preferred for the water-absorbing polymer to have a particle size distribution of between 10 and 500 μm and/or a residual moisture content of less than 10% by weight, preferably less than or equal to 3% by weight. [0209] The above particle size distributions and particle sizes, and also residual moisture contents, are particularly advantageous for uniform delivery and distribution of the active substances and for good wear comfort. It has emerged, moreover, that the above particle size distributions and particle sizes can be incorporated particularly effectively into flexible matrices, which, when incorporated into plasters or wound contact materials, raises the conformability of these plasters or wound contact materials to the shape of the wound and to its movements. [0210] Finally, the matrix may be lined with an adhesive-repellant backing material, such as siliconized paper, or may be provided with a wound contact material or cushioning. On its preferably self-adhesive side which later faces the skin, the dressing of the invention is lined over its whole width, up until the time of use, typically with an adhesive-repellant backing material. This material protects the self-adhesive layer, which comprises the highly skin-compatible adhesive of the matrix and has been applied preferably by the transfer method, and, additionally, stabilizes the entire product. The liner may be designed in a known way as a single piece or, preferably, in two parts. [0211] The wound dressing of the invention, mostly in the form of a plaster, preferably comprises a self-adhesive polyurethane matrix of the invention, comprising active substance, an active-impermeable backing layer, and a detachable protective layer, which is removed prior to application to the skin. Further ingredients, such as filler, stabilizers, enhancers and/or cosmetic adjuvants, may be incorporated in the matrix in order to tailor the dressing to the different fields of application and in order to provide a dressing which is amiable in application. [0000] For the purpose of explanation, [0212] FIG. 1 shows one preferred embodiment of the wound dressing [0213] FIG. 2 shows the distribution of the actives in the water-absorbing polymer in versions I, II and III (see examples). [0214] A corresponding bandage is constructed from a backing such as films, nonwovens, wovens, foams ( 1 ) etc., the adhesive matrix ( 2 ), and liner sheet, liner material or release paper ( 3 ) to protect the adhesive matrix prior to use of the bandage, as depicted in FIG. 1 . [0215] In a further preferred embodiment of the invention, polymer sheets, nonwovens, wovens and combinations thereof are used as backings. Backing materials available for selection include polymers such as polyethylene, polypropylene, polyesters, polyether-esters and polyurethane, or else natural fibers. The thickness of the respective layers ( 1 , 2 , 3 ) is in the region of [0000] (1) 10-150 μm [0000] (2) 50-2000 μm [0000] (3) 20-200 μm. [0216] In summary it can be stated that suitable backing materials include all rigid and elastic sheet-like structures of synthetic and natural raw materials. Preference is given to backing materials which can be employed in such a way that they fulfill properties of a functional dressing. Recited by way of example are textiles such as wovens, knits, lays, nonwovens, laminates, nets, films, foams, and papers. Furthermore, these materials may be pretreated and/or aftertreated. Common pretreatments are corona and hydrophobizing; customary post-treatments are calendering, thermal conditioning, laminating, die-cutting, and enveloping. [0217] It is particularly advantageous if the backing material is sterilizable, preferably γ (gamma) sterilizable. γ sterilization (dose=30 kGy) did not show any effect on the wound dressing of the invention. [0218] The aforementioned properties of the adhesive matrix suggest in particular the use of the wound dressings of the invention for medical products, especially bandages, medical attachments, wound covers, and orthopedic or phlebological bandages, and dressings. [0219] The wound dressings of the invention are capable of drawing up wound exudate and moisture from the skin and, where appropriate, of transporting it outward through the bandage. This produces an optimum moist wound healing environment. On the basis of the skin-compatibility and the painless redetachability, furthermore, preconditions important to the user for the use of the wound dressing of the invention are provided. [0220] Besides its application as a dressing, plaster or bandage material, the contact material of the invention may also be employed as a skin care product. For that purpose it may incorporate not only the active-doped superabsorbents present in accordance with the invention but also further substances, especially skincare, skin-moisturizing or skin-healing substances. A further possible use of the contact material is as a moist or dry cosmetic wipe or pad. DETAILED DESCRIPTION OF THE INVENTION Examples [0000] A. Production of Laboratory Specimens with Dexpanthenol-Doped Superabsorber [0221] 1. Preparation of the two Compositions Component 1: 82% by weight polyether polyol* Levagel E (Bayer AG)  9% by weight isocyanate prepolymer** Desmodur (Bayer AG)  9% by weight Favor T, doped with 10% dexpanthenol (Degussa Stockhausen AG) are weighed and mixed on a roller bed for 24 hours. Component 2: 90% by weight polyether polyol* 10% by weight catalyst*** CosCat (CasChem Inc.) *Pentaerythritol + propylene oxide + ethylene oxide copolymer with ethylene oxide end block Functionality: 4, OH number: 35, average molar weight: 6400 (calculated). Viscosity (23° C.): 1000 mPas, ethylene oxide content: 20% by weight **NCO-terminated prepolymer from reaction at 80° C. of hexamethylene diisocyanate and polypropylene glycol (average molecular weight: 220) in a molar ratio of 5:1 and subsequent vacuum distillation at approximately 0.5 mbar down to a residual HDI monomer content <0.5% by weight NCO content: 12.6% by weight, viscosity (23° C.): 5000 mPas ***Solution of 1 mol of the Bi(III) salt with 2,2-dimethyloctanoic acid in 3 mol of 2,2-dimethyoctanoic acid (bismuth content approximately 17% by weight) [0222] 2. Production of Coatings Materials for use: component 1 component 2 Sheet with a water vapor permeability ofapproximately 750 g/(m 2 * d) Procedure: 98% by weight component 1  2% by weight component 2 are weighed out and mixed for approximately 40 s, poured onto release paper, the film is laminated on ahead of the coating bar, and the PU composition is coated out between release paper and sheet, using the coating bar: Slot setting on the coating bar: 1 mm [0223] Curing of the coated-out PU composition at 65° C. for 5 minutes [0224] From the coating (coat weight of approximately 850 g/m 2 ) it is possible to die-cut contact materials. [0225] Illustrated below by way of example is the production of a wound dressing of the invention. [0226] A. Preparation of polyacrylic acid-based superabsorber doped with dexpanthenol The superabsorber is prepared by customary methods, by initiating the polymerization of aqueous acrylic acid solution at a temperature of approximately 150° C. The water content of the solution is approximately 70% by weight. Even at this point (I) it is already possible to add the dexpanthenol to the polymerization solution. The result is a dexpanthenol-doped superabsorber of version (I) as depicted in FIG. 2 . The resultant polymer is comminuted and dried at approximately 150° C. It is likewise possible to add dexpanthenol (II) subsequently, hence giving a dexpanthenol-doped superabsorber of version (II). This later addition of dexpanthenol has the advantage that the dexpanthenol has not been exposed to the prior drying. The polymer is ground further and, where appropriate, surface-modified and dried. It is likewise possible to add the dexpanthenol at this point (III). This produces a dexpanthenol-doped superabsorber of version (III). The polymer is subsequently dried at approximately 150° C. down to a residual moisture content of approximately 7% to 10%. [0227] Advantageously, two further process steps (IV and V) then follow, which optimize first the particle size and secondly the residual moisture content of the dexpanthenol-doped superabsorber. [0228] Thereafter the dexpanthenol-doped polymer dried after process step (III) is ground. The superabsorber (IV) then has a particle size distribution of approximately 10 to 500 μm, preferably 20 to 200 μm. [0229] As a last process step (V) the doped superabsorber is dried again. The drying leads to a residual moisture content of less then 10%, preferably ≦3%, in the doped superabsorber (V). [0230] In comparison between the doped superabsorbers of versions I to V that can be prepared, a number of differences become apparent, as shown in FIG. 2 . With the same amount of dexpanthenol employed, in the case of version (I) the dexpanthenol is homogeneously distributed within the superabsorber particles. In the case of version (II), the dexpanthenol is distributed in an outer ring of the particles, and in the case of version (III) all of the dexpanthenol is located only on the outermost layer of the particle surface. The result of the two latter versions (II) and (III) is that, owing to the accumulation of dexpanthenol at the surface, the superabsorber in part becomes more tacky and hence processing may become more difficult. [0231] Version (IV), with a max. particle size of 500 μm and a minimum particle size above the pulmonary access level, represents the optimum particle size distribution. Hence effective further processing of the doped superabsorber particles is ensured. [0232] Version (V), with a residual moisture content of less than 10%, is another optimized version of the dexpanthenol-doped superabsorber. [0233] A superabsorber which has proven particularly preferable for use in the wound dressings of the invention, accordingly, is a dexpanthenol-doped superabsorber of the combination of versions I, IV and V. In this optimum doped superabsorber the dexpanthenol is homogeneously distributed within the particles of absorbent. The particles of the absorbent have a size distribution of between 10 and 500 μm and possess a residual moisture content of less than 10%, preferably less than or equal to 3%. [0234] As a result of the different preparation options (version I, II and/or III in accordance with FIG. 2 ) a breadth of variation is created in the active substance release kinetics as well. Version I generates a long-lasting release, with, advantageously, homogeneous distribution of the active substance in the polymer. Through a combination of the individual preparation steps it is therefore possible to tailor release ranges of the active substances. Hence the active substance can be released in a relatively short time and high dose through to long-lasting delivery in a low dose. [0000] B. Production of the Wound Dressing [0235] These doped superabsorber particles are then added directly to the initial mixture for the polyurethane reaction. Not only the uniform distribution of the dexpanthenol in the superabsorber (version I) but also a residual moisture content of less than or equal to 3% (version V) do not cause any adverse effect, disruptive to the production operation, on the formation of the polyurethane. Polyurethane formation hence proceeds without disruption, as described above. The polyurethane matrix comprising the doped superabsorber is subsequently poured out onto release paper and lined with a polyurethane sheet. [0236] This polyurethane matrix, enveloped between polyurethane sheet and release paper, is manufactured as bales and brought to the appropriate web width on master rolls. From the webs it is possible to die-cut the appropriate-sized wound contact materials. These self-adhesive wound contact materials can themselves be used as plasters and have, accordingly, a structure corresponding to FIG. 1 . [0237] In a further process step, these polyurethane wound contact materials with doped superabsorbers can be placed onto a backing material with an adhesive. From this backing material, finally, the finished bandage with adhesive margin of appropriate size can be die-cut. Suitable backing materials are the materials which are known in bandage technology, such as sheets of polyurethane, polyethylene, polypropylene, polyamide, polyester or polyether-ester and also wovens, fleece, nonwovens, knits, lays, laminates, nets, sheets, foams or papers. It is likewise possible to use any known adhesives, such as acrylate or hot-melt polyurethane. [0238] The polyurethane sheet used in the production operation is optional. It is likewise possible to apply and further process the polyurethane matrix only on the release paper, which means that the polyurethane sheet is then absent from the finished wound dressing.

A skin or wound contact material which comprises a polycondensate matrix and a water-absorbing polymer incorporated therein. The water-absorbing polymer is doped with a wound healing promoter substance and/or a skin care substance.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cascade scanning optical system having a pair of laser scanning optical systems which are arranged along the main scanning direction and controlled to operate in synchronization with each other so as to realize a wide scanning line. More specifically the present invention relates to an apparatus of such a cascade scanning optical system, having a pair of laser scanning optical systems, for synchronizing the rotation of a polygon mirror of one laser scanning optical system with the rotation of a polygon mirror of the other laser scanning optical system, to prevent a pair of scanning lines that are to be aligned, respectively generated by the pair of laser scanning optical systems, from being deviated from each other in the sub-scanning direction. 2. Description of the Related Art A cascade scanning optical system having a plurality of laser scanning optical systems arranged along the main scanning direction to realize a wide scanning line is known. Such a type of scanning optical system is disclosed in Japanese Laid-Open Patent Publication No. 61-11720, published on Jan. 20, 1986. This publication discloses a cascade scanning optical system having a pair of laser scanning optical systems each having a laser beam emitter, a polygon mirror serving as a deflecting device, an fθ lens, etc. The pair of laser scanning optical systems are synchronously driven to emit respective scanning laser beams to a photoconductive surface (scanning surface) of a photoconductive drum on a common line thereon extending in parallel to the axial direction of the photoconductive drum. The pair of scanning laser beams respectively scan two adjacent ranges of the common line on the photoconductive surface so as to scan the photoconductive surface of the photoconductive drum in the main scanning direction in a wide range. There is a fundamental problem to be overcome in such a type of cascade scanning optical system. Namely, how can a scanning line, made on the photoconductive drum by the scanning laser beam emitted from one laser scanning optical system of the cascade scanning optical system, be accurately aligned with another scanning line, made on the photoconductive drum by the scanning laser beam emitted from another laser scanning optical system of the cascade scanning optical system, so that the scanning lines are not apart from each other in either the main scanning direction or the sub-scanning direction, i.e., so as to form a straight and continuous scanning line through the combination of the separate scanning lines. It is sometimes the case that each reflecting surface (scanning laser beam deflecting surface) of a polygon mirror used in the cascade scanning optical system slightly tilts from its original position. In the case where the angle of each reflecting surface of the polygon mirror of one laser scanning optical system is different from that of the other corresponding laser scanning optical system, the pair of scanning lines, which are respectively generated by the aforementioned corresponding reflecting surfaces forming a straight and continuous scanning line, will deviate from each other in the sub-scanning direction on the photoconductive drum. This results in a gap or deviation occurring between the two scanning lines in the sub-scanning direction, so that a straight and continuous scanning line will not be formed. A similar problem will arise in the case where one or both of the polygon mirrors rotate with a tremor or oscillation. SUMMARY OF THE INVENTION The primary object of the present invention is to provide a synchronizing apparatus of a cascade scanning optical system which can prevent a scanning line, made by the scanning laser beam emitted from one laser scanning optical system, and another scanning line, made by the scanning laser beam emitted from the other laser scanning optical system, from far deviating from each other in the sub-scanning direction on a scanning surface. To achieve the object mentioned above, according to an aspect of the present invention, there is provided a cascade scanning optical system which includes: a first laser scanning optical system having a first polygon mirror, provided with a plurality of first reflecting surfaces, for deflecting a first scanning laser beam to scan a part of a scanning surface to generate a first scanning line; a second laser scanning optical system having a second polygon mirror, provided with a plurality of second reflecting surfaces, for deflecting a second scanning laser beam to scan another part of the scanning surface to generate a second scanning line, wherein the first and second laser scanning optical systems are arranged so as to align the first scanning line with the second scanning line at a point of contact therebetween in a main scanning direction to form a single scanning line; means for measuring a degree of tilt of each of the plurality of first reflecting surfaces and the plurality of second reflecting surfaces; and means for determining combinations of the plurality of first reflecting surfaces with the plurality of second reflecting surfaces in accordance with results of measurements of the measuring means so that the single scanning line is formed by any one of the combinations while minimizing a phase difference between a first phase formed by degrees of tilt of the plurality of first reflecting surfaces and a second phase formed by degrees of tilt of the plurality of the second reflecting surfaces. Preferably, the determining means includes means for comparing the degrees of tilt of the plurality of first reflecting surfaces with the degrees of tilt of the plurality of the second reflecting surfaces to judge which reflecting surface of the plurality of first reflecting surfaces has the closest degree of tilt to a reflecting surface of the plurality of the second reflecting surfaces. Preferably, the measuring means includes: a first position sensitive device for detecting a position of the first scanning laser beam in a sub-scanning direction perpendicular to the main scanning direction to determine the degree of tilt of each of the plurality of first reflecting surfaces; and a second position sensitive device for detecting a position of the second scanning laser beam in the sub-scanning direction to determine the degree of tilt of each of the plurality of second reflecting surfaces. Preferably, the first position sensitive device is positioned outside a first optical path through which the first scanning laser beam passes to form the first scanning line, and wherein the second position sensitive device is positioned outside a second optical path through which the second scanning laser beam passes to form the second scanning line. Preferably, the cascade scanning optical system further includes means for storing the degree of tilt of each of the plurality of first reflecting surfaces and the plurality of second reflecting surfaces. Preferably, the storing means includes: a first memory for storing the degree of tilt of each of the plurality of first reflecting surfaces; and a second memory for storing the degree of tilt of each of the plurality of second reflecting surfaces. Preferably, the determining means includes means for comparing the degrees of tilt of the plurality of first reflecting surfaces which are stored in the first memory with the degrees of tilt of the plurality of the second reflecting surfaces which are stored in the second memory to judge which reflecting surface of the plurality of first reflecting surfaces has the closest degree of tilt to a reflecting surface of the plurality of the second reflecting surfaces so as to determine the combinations. Preferably, the measuring means and the determining means each start operating each time a power switch of the cascade scanning optical system is turned ON. Preferably, the cascade scanning optical system further includes a drum having the scanning surface on a periphery of the drum. Preferably, the first and second laser scanning optical systems are composed of the same optical elements. Preferably, the first and second laser scanning optical systems are symmetrically arranged. According to another aspect of the present invention, there is provided a synchronizing apparatus of a cascade scanning optical system, the cascade scanning optical system including a pair of laser scanning optical systems each having a polygon mirror provided with a plurality of reflecting surfaces, the pair of laser scanning optical systems being arranged to form a single scanning line, wherein the synchronizing apparatus includes: means for measuring a degree of tilt of each of the plurality of reflecting surfaces of the polygon mirrors; and means for determining combinations of the plurality of reflecting surfaces of one of the polygon mirrors with the plurality of reflecting surfaces of the other of the polygon mirrors in accordance with results of measurements of the measuring means so that the single scanning line is formed by any one of the combinations while minimizing a phase difference between a first phase formed by degrees of tilt of the plurality of reflecting surfaces of the one of the polygon mirrors and a second phase formed by degrees of tilt of the plurality of the reflecting surfaces of the other of the polygon mirrors. The present disclosure relates to subject matter contained in Japanese Patent Application No. 8-348106 (filed on Dec. 26, 1996) which is expressly incorporated herein by reference in its entirety. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described below in detail with reference to the accompanying drawings in which: FIG. 1 is a perspective view of an embodiment of a cascade scanning optical system to which the present invention is applied, showing only fundamental elements thereof; FIG. 2 is a plan view of a part of the cascade scanning optical system shown in FIG. 1; FIG. 3A is a graph showing the degree of tilt of each reflecting surface of the first of the pair of polygon mirrors shown in FIG. 1 or 2 in one example; FIG. 3B is a graph showing the degree of tilt of each reflecting surface of the second of the pair of polygon mirrors shown in FIG. 1 or 2 in the one example; and FIG. 4 is a block diagram of a synchronizing apparatus of the cascade scanning optical system. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows an embodiment of a cascade scanning optical system for scanning the photoconductive surface of a photoconductive drum (rotating member) 10 provided in a laser-beam printer. The cascade scanning optical system is provided with a pair of laser scanning optical systems, i.e., a first scanning optical system 20A and a second scanning optical system 20B. The first and second optical systems 20A and 20B are each designed as a non-telecentric system, so that the incident angle of a scanning laser beam emitted from each of the first and second optical systems 20A and 20B relative to the photoconductive surface of the drum 10 varies in accordance with a variation in the position of the scanning spot of the scanning laser beam on the photoconductive surface in the main scanning direction. The first and second scanning optical systems 20A and 20B are provided with the same optical elements or parts, that is, the first scanning optical system 20A is provided with a laser collimating unit 21A serving as a laser beam emitter, a cylindrical lens 23A, a polygon mirror (scanning laser beam deflector) 24A, an fθ lens group 25A, an auxiliary lens 26A and a mirror 27A, while the second scanning optical system 20B is provided with a laser collimating unit 21B serving as a laser beam emitter, a cylindrical lens 23B, a polygon mirror (scanning laser beam deflector) 24B, an fθ lens group 25B, an auxiliary lens 26B and a mirror 27B. Each of the fθ lens groups 25A and 25B consists of two lens elements as can be seen from FIG. 1. The first and second scanning optical systems 20A and 20B are arranged side by side in a direction parallel to the axial direction of the drum 10 and are supported by a common casing 35 on an inner flat surface thereof. The laser collimating units 21A and 21B are identical. Each of the laser collimating units 21A and 21B is provided therein with a laser diode LD and a collimating lens group (not shown) for collimating a laser beam emitted from the laser diode LD. In each of the first and second scanning optical systems 20A and 20B, the laser beam emitted from the laser diode LD is collimated through the collimating lens group. Thereafter this collimated laser beam is incident upon the cylindrical lens 23A or 23B positioned in front of the corresponding laser collimating unit 21A or 21B. Each cylindrical lens 23A or 23B has a power in the sub-scanning direction, so that the spot of the laser beam incident thereon is elongated therethrough in the main scanning direction to be incident upon the corresponding polygon mirror 24A or 24B. The polygon mirrors 24A and 24B are each rotated, so that laser beams incident thereon are deflected in the main scanning direction to proceed toward the mirrors 27A and 27B through the fθ lens groups 25A and 25B and the auxiliary lenses 26A and 26B, respectively. Subsequently, the laser beams incident upon the mirrors 27A and 27B are reflected thereby towards the photoconductive drum 10, to thereby scan the same in the main scanning direction. Each of the auxiliary lenses 26A and 26B has a power mainly in the sub-scanning direction. In order to reduce the size of the cascade scanning optical system, it is possible to omit each of the auxiliary lenses 26A and 26B. In such a case, the design of the fθ lens groups 25A and 25B would be modified in such a way that they would have the equivalent power to that of the combined power of the original fθ lens groups 25A and 25B and the auxiliary lenses 26A and 26B, respectively. In FIG. 2, "X" represents an optical axis of the fθ lens group 25A or 25B. The optical axis X extends perpendicular to the main scanning direction. "S" represents the photoconductive surface of the drum 10. The auxiliary lenses 26A and 26B and the mirrors 27A and 27B are not illustrated in either FIG. 2 or 4. The polygon mirror 24A rotates in a clockwise direction while the polygon mirror 24B rotates in a counterclockwise direction, as viewed in FIG. 2. Namely, the polygon mirrors 24A and 24B rotate in opposite rotational directions to scan the photoconductive surface of the drum 10 from its approximate center toward respective opposite ends in opposite directions. A mirror 28A is fixedly provided in the casing 35 at a position to receive the scanning laser beam emitted from the fθ lens group 25A before the scanning laser beam is incident on the photoconductive surface of the drum 10 through the auxiliary lens 26A and the mirror 27A at each scanning sweep while the polygon mirror 24A rotates. The laser beam reflected by the mirror 28A is incident on a laser beam detector (BD) 29A fixedly provided in the casing 35 at a position opposite to the mirror 28A. Likewise, a mirror 28B is fixedly provided in the casing 35 at a position to receive the scanning laser beam emitted from the fθ lens group 25B before the scanning laser beam is incident on the photoconductive surface of the drum 10 through the auxiliary lens 26B and the mirror 27B at each scanning sweep while the polygon mirror 24B rotates. The laser beam reflected by the mirror 28B is incident on a laser beam detector (BD) 29B fixedly provided in the casing 35 at a position opposite to the mirror 28B. The laser diodes LD of the laser collimating units 21A and 21B are each controlled to turn its laser emission ON or OFF in accordance with given image data to draw a corresponding image (charge-latent image) on the photoconductive surface of the drum 10, and subsequently this image drawn on the photoconductive surface of the drum 10 is transferred to plain paper according to a conventional electrophotographic method. The polygon mirrors 24A and 24B are controlled synchronously with the use of the laser beam detectors 29A and 29B such that on the photoconductive surface of the drum 10 the scanning starting point of a spot of the scanning laser beam emitted from the first scanning optical system 20A is properly and precisely adjacent to the scanning starting point of a spot of the scanning laser beam emitted from the second scanning optical system 20B, and that those two spots move in opposite directions apart from each other in the main scanning direction to thereby form a wide scanning line on the photoconductive surface of the drum 10. With the rotational movement of the photoconductive drum 10 which is synchronized to the rotational movement of each of the polygon mirrors 24A and 24B, a series of wide scanning lines are made on the photoconductive surface of the drum 10 to thereby obtain a certain image (charge-latent image) on the photoconductive surface of the drum 10. The polygon mirror 24A has a regular hexagonal cross section and is provided along a circumference thereof with six reflecting surfaces (scanning laser beam deflecting surfaces) A, B, C, D, E and F. Likewise, the polygon mirror 24B has a regular hexagonal cross section and is provided along a circumference thereof with corresponding six reflecting surfaces (scanning laser beam deflecting surfaces) a, b, c, d, e and f. In either polygon mirror 24A or 24B, there is a possibility of each reflecting surface tilting from its original position. Such tilt causes the position of the spot of the corresponding scanning laser beam to deviate on the photoconductive surface in the sub-scanning direction. In the case where the degree (amount) of tilt of one reflecting surface of the polygon mirror 24A is different from that of a corresponding reflecting surface of the polygon mirror 24B, opposing ends of two scanning lines to be combined which are formed by a pair of scanning laser beams on the photoconductive surface will be apart from each other in the sub-scanning direction. With a synchronizing apparatus which will be hereinafter discussed such a problem of deviation of opposing ends of the two scanning lines in the sub-scanning direction is effectively prevented from occurring. A first PSD (semiconductor position sensitive device) 31A is fixedly provided in the casing 35 at a position in the vicinity of the laser beam detector 29A to receive the scanning laser beam emitted from the fθ lens group 25A after the scanning laser beam has completed a single scanning at each scanning sweep while the polygon mirror 24A rotates. Likewise, a second PSD (semiconductor position sensitive device) 31B is fixedly provided in the casing 35 at a position in the vicinity of the laser beam detector 29B to receive a laser beam emitted from the fθ lens group 25B after the scanning laser beam has completed a single scanning at each scanning sweep while the polygon mirror 24B rotates. Each PSD 31A, 31B detects the position of a scanning laser beam received, emitted from the corresponding polygon mirror 24A or 24B, in the sub-scanning direction so as to determine the degree of tilt of each reflecting surface of the corresponding polygon mirror 24A or 24B. FIG. 3A is a graph showing the degree of tilt of each reflecting surface (A, B, C, D, E and F) of the polygon mirror 24A while FIG. 3B is a graph showing the degree of tilt of each reflecting surface (a, b, c, d, e and f) of the polygon mirror 24B, in an example. As can be seen from FIGS. 3A and 3B, in either polygon mirror 24A or 24B the degree of tilt periodically varies to substantially form a sine curve. In the present embodiment a point at which the phases of the two sine curves coincides with each other most is determined to synchronize the rotation of the polygon mirror 24A with the rotation of the polygon mirror 24B so as to form a wide scanning line on the photoconductive surface of the drum 10 by a corresponding pair (determined pair) of reflecting surfaces of the polygon mirrors 24A and 24B. In the illustrated particular example shown in FIGS. 3A and 3B, a deviation of a pair of scanning lines respectively generated by the polygon mirrors 24A and 24B on the photoconductive surface in the sub-scanning direction will be greatly reduced or substantially eliminated if the rotation of the polygon mirror 24A is synchronized with the rotation of the polygon mirror 24B with the reflecting surface `A` of the polygon mirror 24A coincident with the reflecting surface `e` of the polygon mirror 24B, as will be appreciated from FIGS. 3A and 3B. FIG. 4 shows a block diagram of the synchronizing apparatus of the cascade scanning optical system which realizes the aforementioned synchronizing process. The first and second polygon mirrors 24A and 24B are rotated by first and second motor units 55A and 55B, respectively. When the first and second motor units 55A and 55B start operating upon the power switch turned ON, the motor units 55A and 55B are each controlled, rotating with common clock pulses output from a frequency divider 53 which receives clock pulses from a clock pulse generator 51. After the rotation of each motor unit 55A, 55B has become stable and the PLL (phase-lock loop) starts, the rotational speed of the second polygon mirror 24B, i.e., the rotational speed of the second motor unit 55B, is controlled in accordance with signals which are output from the second laser beam detector 29B each time the first laser beam detector 29A detects the laser beam emitted from the first polygon mirror 24A. The first laser beam detector 29A outputs a signal to both a first phase detecting circuit 57A and a phase-difference detector 59 at the time the first laser beam detector 29A detects a scanning laser beam. The second laser beam detector 29B outputs a signal to each of: a second phase detecting circuit 57B, the phase-difference detector 59, and a delay circuit (time-delay circuit) 81 at the time the second laser beam detector 29B detects a scanning laser beam. The phase-difference detector 59 determines a phase difference between the phase of signals output from the first laser beam detector 29A and the phase of signals output from the second laser beam detector 29B in accordance with the signals input from the first and second laser beam detectors 29A and 29B to output a phase difference indicating voltage to an LPF (low pass filter) 61. The terms "phase difference indicating voltage" herein used mean a voltage which indicates the magnitude of a phase difference. In the case where the phase of signals output from the second laser beam detector 29B follows the phase of signals output from the first laser beam detector 29A, the phase-difference detector 59 outputs a positive phase difference indicating voltage. Conversely, in the case where the phase of signals output from the second laser beam detector 29B precedes the phase of signals output from the first laser beam detector 29A, the phase-difference detector 59 outputs a negative phase difference indicating voltage. Inputting a phase difference indicating voltage output from the phase-difference detector 59, the LPF 61 converts the phase difference indicating voltage into a DC voltage corresponding to the magnitude of the input phase difference indicating voltage. Subsequently, the LPF 61 outputs the DC voltage to a VCO (voltage controlled oscillator) 63. The VCO 63 changes the frequency of clock pulses output therefrom in accordance with the DC voltage input from the LPF 61 In this particular embodiment, the VCO 63 outputs clock pulses having a high frequency to a multiplexer 67 when the DC voltage input from the LPF 61 is a high voltage, while the VCO 63 outputs clock pulses having a low frequency to the multiplexer 67 when the DC voltage input from the LPF 61 is a low voltage. The multiplexer 67 adjusts clock pulses input from the frequency divider 53 in accordance with clock pulses input from the VCO 63 to output the adjusted clock pulses to the second motor unit 55B. Accordingly, in the case where the phase of signals output from the second laser beam detector 29B follows that of the first laser beam detector 29A, the rotational speed of the second motor unit 55B increases. Conversely, in the case where the phase of signals output from the second laser beam detector 29B precedes that of the first laser beam detector 29A, the rotational speed of the second motor unit 55B decreases. When detecting a scanning laser beam, each PSD 31A, 31B outputs a voltage corresponding to the detected position of the received scanning laser beam. The voltage output from the first PSD 31A is converted into digital signals by an A/D converter 71A to be stored in a data memory 73A as data (first data group) representing the degrees of tilt of the reflecting surfaces A, B, C, D, E and F of the first polygon mirror 24A. Similarly, the voltage output from the second PSD 31B is converted into digital signals by an A/D converter 71B to be stored in a data memory 73B as data (second data group) representing the degrees of tilt of the reflecting surfaces a, b, c, d, e and f of the second polygon mirror 24B. It is preferable to measure each of the aforementioned first and second data groups more than once and store the average values of the first data group and the average values of the second data group in the data memories 73A and 73B, respectively, so as to improve the reliability of each of the first and second data groups. After the degrees of tilt of the reflecting surfaces of the first polygon mirror 24A have all been stored in the data memory 73A, a reflecting-surface position detecting circuit 75A firstly detects the degree of tilt of any one of the reflecting surfaces of the first polygon mirror 24A, which rotates at a fixed rotational speed, by inputting a signal from the first PSD 31A through the A/D converter 71A. Subsequently the reflecting-surface position detecting circuit 75A inputs the values from the first data group stored in the data memory 73A and compares each stored degree of tilt in the first data group with the detected degree of tilt of the aforementioned reflecting surface of the first polygon mirror 24A to determine which one of the reflecting surfaces A, B, C, D, E or F of the first polygon mirror 24A is the aforementioned reflecting surface of the first polygon mirror 24A. Thereafter the reflecting-surface position detecting circuit 75A outputs the data (first surface data) representing one of the reflecting surfaces A, B, C, D, E or F of the first polygon mirror 24A which is the aforementioned reflecting surface of the first polygon mirror 24A, to a motor speed controller 77. Likewise, after the degrees of tilt of the reflecting surfaces of the second polygon mirror 24B have all been stored in the data memory 73B, a reflecting-surface position detecting circuit 75B firstly detects the degree of tilt of any one of reflecting surfaces of the second polygon mirror 24B, which rotates at a fixed rotational speed, by inputting a signal from the second PSD 31B through the A/D converter 71B. Subsequently the reflecting-surface position detecting circuit 75B inputs the values of the second data group stored in the data memory 73B and compares each stored degree of tilt in the second data group with the detected degree of tilt of the aforementioned reflecting surface of the second polygon mirror 24B to determine which one of the reflecting surfaces a, b, c, d, e or f of the second polygon mirror 24B is the aforementioned reflecting surface of the second polygon mirror 24B. Thereafter the reflecting-surface position detecting circuit 75B outputs the data (second surface data) representing one of the reflecting surfaces a, b, c, d, e or f of the second polygon mirror 24B which is the aforementioned reflecting surface of the second polygon mirror 24B, to the motor speed controller 77. The motor speed controller 77 compares the first surface data input from the reflecting-surface position detecting circuit 75A and the corresponding data stored in the data memory 73A which represents the degree of tilt of the aforementioned reflecting surface of the first polygon mirror 24A with the second surface data input from the reflecting-surface position detecting circuit 75B and the corresponding data stored in the data memory 73B which represents the degree of tilt of the aforementioned reflecting surface of the second polygon mirror 24B to determine a phase difference between the phase of the degrees of tilt of reflecting surfaces of the first polygon mirror 24A and the phase of the degrees of tilt of reflecting surfaces of the second polygon mirror 24B. Namely, it is determined which degree of tilt of the reflecting surfaces A, B, C, D, E or F of the first polygon mirror 24A is closest to which degree of tilt of the reflecting surfaces a, b, c, d, e or f of the second polygon mirror 24B. Thereafter, with the reflecting surfaces A, B, C, D, E and F of the first polygon mirror 24A regarded as reference surfaces, the motor speed controller 77 converts the phase difference into a voltage (phase difference indicating voltage) to be output to the LPF 61. The LPF 61 converts the voltage input from the motor speed controller 77 into a DC voltage corresponding to the magnitude of the input voltage and outputs the DC voltage to the VCO 63. The VCO 63 varies the frequency of clock pulses output therefrom in accordance with the DC voltage input from the LPF 61. Due to the variation in frequency of clock pulses output from the VCO 63, the rotational speed of the second motor unit 55B is controlled to increase or decrease so as to match the phase of a sine curve formed by the degrees of tilt of the reflecting surfaces of the first polygon mirror 24A with the phase of a sine curve formed by the degrees of tilt of the reflecting surfaces of the second polygon mirror 24B, so that the combinations of the reflecting surfaces A, B, C, D, E and F with the reflecting surfaces a, b, c, d, e and f change, i.e., the correspondence of each of the reflecting surfaces A, B, C, D, E and F with a corresponding reflecting surface a, b, c, d, e or f changes. At the time the motor speed controller 77 detects a condition that the data representing the degree of tilt of any one of the reflecting surfaces A, B, C, D, E and F substantially corresponds to the data representing the degree of tilt of a corresponding reflecting surfaces a, b, c, d, e or f which is currently synchronized with the aforementioned any one of the reflecting surfaces A, B, C, D, E and F, the motor speed controller 77 stops outputting the voltage (phase difference indicating voltage) to the LPF 61 so as to maintain the current phase (correspondence of reflecting surfaces), which completes the synchronizing process of the present embodiment. Thereafter the synchronization of rotation of the first and second polygon mirrors 24A and 24B is maintained according to the phase difference indicating voltage output from the phase-difference detector 59. In the illustrated particular example shown in FIGS. 3A and 3B, after the above synchronizing process has been completed, the reflecting surface A of the first polygon mirror 24A corresponds to the reflecting surface e of the second polygon mirror 24B. Accordingly, the motor speed controller 77 adjusts the rotational speed of the second motor unit 55B to synchronize the reflecting surface A of the first polygon mirror 24A with the reflecting surface e of the second polygon mirror 24B. The motor speed controller 77 can determine the phase difference between the sine curve of the degrees of tilt of reflecting surfaces of the first polygon mirror 24A and the sine curve of the degrees of tilt of reflecting surfaces of the second polygon mirror 24B, using all the aforementioned data input from each of the data memories 73A and 73B and the reflecting-surface position detecting circuits 75A and 75B, in accordance with either one of the following two practical methods. [First method] Regarding each of the first and second polygon mirrors 24A and 24B, among the data representing the degrees of tilts of the six reflecting surfaces a specific reflecting surface whose degree of tilt is the largest is ranked as Level 3. The other five reflecting surfaces which follow the specific reflecting surface in time order are ranked Levels 4, 5, 6, 1 and 2, respectively. In the example shown in FIG. 3A the reflecting surface B is ranked as Level 3. In the example shown in FIG. 3B the reflecting surface f is ranked as Level 3. Thereafter, one of the reflecting surfaces of the second polygon mirror 24B which is currently synchronized with the aforementioned specific reflecting surface of the first polygon mirror 24A whose degree of tilt is the largest is detected. Subsequently the Level value of the detected one of the reflecting surfaces of the second polygon mirror 24B is subtracted from the Level value of the aforementioned specific reflecting surface. The larger the absolute value of the result of such a subtraction is, the larger the phase difference is. Therefore, an amount of variation in the number of revolutions of the second polygon mirror 24B per a certain period of time can be determined based on the result of the aforementioned subtraction. At the same time, by knowing whether the result of the subtraction is a negative value or a positive value, it can be judged whether the phase of the sine curve representing the degrees of tilt of reflecting surfaces of the second polygon mirror 24B precedes or follows the phase of the sine curve representing the degrees of tilt of reflecting surfaces of the first polygon mirror 24A, i.e., whether the number of revolutions of the second polygon mirror 24B per a certain period of time should be increased or decreased can be determined. This operation is completed when the result of the aforementioned subtraction becomes zero (0). In this first method, although a specific reflecting surface whose degree of tilt is the largest is ranked as Level 3, a specific reflecting surface whose degree of tilt is the smallest may be ranked as Level 3 (reference level). [Second Method] The value of the degree of tilt of the reflecting surface `a` is subtracted from the value of degree of tilt of one of the reflecting surfaces A, B, C, D, E and F which is currently synchronized with the reflecting surface `a`, and the result of that subtraction is stored in memory. Similarly, the value of the degree of tilt of the reflecting surface `b` is subtracted from the value of the degree of tilt of another one of the reflecting surfaces A, B, C, D, E and F which is currently synchronized with the reflecting surface `b`, and the result of that subtraction is stored in memory. A similar operation is performed for each of the remaining four reflecting surfaces c, d, e and f. After all the six results have been obtained, the number of revolution of the second polygon mirror 24B per a certain period of time is adjusted such that the sum of the absolute values of the six results will be minimal. The processing in either the first or second method can start to be performed each time the power switch of the apparatus is turned ON, i.e. each time the first and second motor units 55A and 55B start operating, or during the idle of each motor units 55A, 55B at the time a certain period of time elapses after the power switch of the apparatus is turned ON. In FIG. 4, "HSYNC 1" and "HSYNC 2" shown on the left side of the drawing each represent a reference signal for commencing an operation of writing main scanning data. A delay circuit (time-delay circuit) 81 delays the output signal by a specific time interval with respect to the input signal, so that the commencement of each scanning sweep made by the second scanning optical system 20B is delayed by the aforementioned specified time interval with respect to the commencement of each scanning sweep made by the first scanning optical system 20A. The data of the specified time interval (delay-time data) is prestored in memory 79, so that the delay circuit 81 inputs the delay-time data from the memory 79 and outputs the reference signal HSYNC 2 in accordance with the delay-time data. As can be understood from the foregoing, according to the present embodiment of the cascade scanning optical system, a deviation between a scanning line made by the scanning laser beam emitted from one laser scanning optical system and another scanning line made by the other laser scanning optical system, which are to be aligned to form a straight and continuous scanning line, can be fallen into an acceptable range of deviation. Obvious changes may be made in the specific embodiments of the present invention described herein, such modifications being within the spirit and scope of the invention claimed. It is indicated that all matter contained herein is illustrative and does not limit the scope of the present invention.

A cascade scanning optical system which includes: a first laser scanning optical system having a first polygon mirror, provided with a plurality of first reflecting surfaces, for deflecting a first scanning laser beam to scan a part of a scanning surface to generate a first scanning line; a second laser scanning optical system having a second polygon mirror, provided with a plurality of second reflecting surfaces, for deflecting a second scanning laser beam to scan another part of the scanning surface to generate a second scanning line, wherein the first and second laser scanning optical systems are arranged so as to align the first scanning line with the second scanning line at a point of contact therebetween in a main scanning direction to form a single scanning line; means for measuring a degree of tilt of each of the plurality of first reflecting surfaces and the plurality of second reflecting surfaces; and means for determining combinations of the plurality of first reflecting surfaces with the plurality of second reflecting surfaces in accordance with results of measurements of the measuring means so that the single scanning line is formed by any one of the combinations while minimizing a phase difference between a first phase formed by degrees of tilt of the plurality of first reflecting surfaces and a second phase formed by degrees of tilt of the plurality of the second reflecting surfaces.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to variable bit rate digital circuit multiplication equipment for carrying out tandem relay of speech. [0003] 2. Description of Related Art [0004] Long-distance telecommunications including international telecommunications and others utilize DCME (Digital Circuit Multiplication Equipment) for reducing communication cost. [0005] DCME is a device for efficiently transmitting voice-band data such as telephone speech, facsimile signals and data modem signals by combining a DSI (Digital Speech Interpolation) technique that transmits only speech activity with a low bit rate speech coding technique. In particular, variable bit rate DCME is a device that can vary its coding bit rate of the telephone speech in response to the load condition on a bearer line (transmission line). [0006] [0006]FIG. 10 is a block diagram showing a configuration of a conventional variable bit rate DCME. In FIG. 10, the reference numeral 1 designates a speech activity decision section for receiving a PCM signal and for making a decision as to whether the input signal to each trunk channel is in speech active state or not; 2 designates a signal discriminating section for receiving the PCM signal and for identifying whether the input signal to each trunk channel is telephone speech or a data signal like a facsimile signal: 3 designates a speech coding section for encoding the PCM signal and outputting a coded speech signal; 4 designates an assignment controller for assigning transmission bit rate of each trunk channel to a bearer line in accordance with the decision result of the speech activity decision section 1 and the identification result of the signal discriminating section 2 ; 5 designates a message generator for generating an assignment message in accordance with the assignment result of the assignment controller 4 ; and 6 designates a multiplexer for multiplexing the coded speech signals of the individual trunk channels output from the speech coding section 3 in accordance with the assignment result by the assignment controller 4 , and for multiplexing the assignment messages generated by the message generator 5 , outputting the multiplexed signal to the bearer line. [0007] The reference numeral 7 designates a demultiplexer that demultiplexes a signal from the bearer line including multiplexed coded speech signals and assignment messages, and supplies the assignment messages to a message decoder 8 and the coded speech signals to a speech decoder 9 ; 8 designates the message decoder that decodes each assignment message provided from the demultiplexer 7 , and supplies the demultiplexer 7 with the decoded result and the speech decoder 9 with the assignment information on each trunk channel and with coding bit rate information; and 9 designates the speech decoder that decodes each coded speech signal provided from the demultiplexer 7 in accordance with the assignment information and coding bit rate information supplied from the message decoder 8 , and sends a resultant PCM signal to each trunk (circuit switch) side channel. [0008] In FIG. 10, the left-hand side is the trunk (circuit switch) side where the telephone speech/voice-band data of a plurality of channels are input or output in a 64-kbit/s PCM (Pulse Code Modulation) scheme. The right-hand side is a bearer (transmission line) side where the low bit rate coded telephone speech/voice-band data (coded speech signals) are transmitted or received. [0009] Here, for convenience-in explanation, it is assumed that the trunk side has a capacity for transferring 600-channel 64-kbit/s telephone speech/voice-band data, and that the bearer side has a line capacity of 2 Mbits/s. It is further assumed in the following description that as the low bit rate speech coding bit rate, the telephone speech transmission uses 8 kbits/s or 6.4 kbits/s, whereas the voice-band data signal transmission utilizes 40 kbits/s. [0010] Next, the operation of the conventional DCME will be described. [0011] The 600-channel 64-kbits/s PCM signals input from the trunk side are supplied to the speech activity decision section 1 , signal discriminating section 2 and speech coding section 3 . [0012] The speech activity decision section 1 decides the speech activity/silence of each trunk channel, and supplies the decision result to the assignment controller 4 . [0013] The signal discriminating section 2 decides as to whether the input signal to each trunk channel is the telephone speech or the data signal like a facsimile signal, and supplies the discrimination result to the assignment controller 4 . [0014] Receiving the decision result and discrimination result from the speech activity decision section 1 and signal discriminating section 2 , the assignment controller 4 decides a bit rate assigned to each trunk channel on the bearer line in accordance with the decision result and discrimination result, and supplies the assignment result to the speech coding section 3 , message generator 5 and multiplexer 6 . [0015] In the assignment to the bearer line, speech activity trunk channels are assigned to the bearer line first. In this case, trunk channels decided as transferring data signals are assigned 40 kbits/s per channel, whereas trunk channels decided as transferring telephone speech are each assigned 8 kbits/s or 6.4 kbits/s. [0016] The coding bit rate is changed depending on the signal types. This is because the information compression principle of the low bit rate speech coding is based on reducing the redundancy of the speech signals by utilizing that redundancy, and hence high-degree compression is possible for the telephone speech, but not for the voice-band data like facsimile signals. [0017] The telephone speech is assigned one of the two bit rates. It is usually assigned 8 kbits/s on the bearer line, which is reduced to 6.4 kbits/s when the bearer line becomes congested to enable new assignment. [0018] As for a 32 kbit/s transmission line, for example, although it is occupied by four 8 kbit/s channels, it can provide five channels for 6.4 kbits/s. [0019] The speech coding section 3 includes 600-channel speech encoders. Referring to coding bit rate information provided from the assignment controller 4 as the assignment result, the speech coding section 3 encodes the input signal from each trunk channel at a bit rate of 8 kbits/s or 6.4 kbits/s when it is the telephone speech, and at a bit rate of 40 kbits/s when it is the voice-band data, and supplies the coded speech signals to the multiplexer 6 . [0020] On the other hand, the message generator 5 generates the assignment message to be transferred to party equipment in accordance with the assignment result of the assignment controller 4 . [0021] An example of the assignment message will now be described with reference to FIG. 11 that shows a structure of a frame (DCME frame) the DCME outputs to the bearer line. In this example, there are 248 bearer channels (BCs) for transmitting the coded speech signals and a message channel for transmitting the assignment message on the bearer line. [0022] Each BC has a capacity of 8 kbits/s so that 248-channel 8-kbit/s coded speech signals are transmitted at the maximum. A 40-kbit/s coded speech signal is transmitted using 5-channel BCs. [0023] Incidentally, the DCME frame length is usually set at an integer multiple of an 8-kbit/s speech coding frame length and a 40-kbit/s speech coding frame length. For example, when the 8-kbit/s speech coding frame length is 10 ms and the 40-kbit/s speech coding frame length is 2.5 ms, the DCME frame length is preferably set at 10 ms. [0024] In the present specification, the DCME frame length is assumed to be 10 ms in the following description (thus, the number of bits in each BC is 10 ms×8000=0.01 s×8000=80 bits). The message channel can transmit four messages, each of which consists of a pair of a trunk channel number (TC number) and a bearer channel number (BC number). For example, when the trunk channel “5” is newly connected to the bearer channel 3 , a message TC number=5 and BC number=3 is transmitted. [0025] Usually, the TC number=0 indicates disconnection. For example, to disconnect the trunk connected to the BC 50 , the message TC number=0 and BC number=50 is transmitted. [0026] Thus, the assignment message is for transmitting to the party equipment the information about how each trunk channel is assigned to the bearer line. To save the message channel capacity, only information about a change in the assignment is formed as a message. Accordingly, when many changes take place as when many trunk channels simultaneously shift from a silent to speech activity state, some channels may have to wait until they are assigned to the bearer line. [0027] In accordance with the assignment result to the bearer line by the assignment controller 4 , the multiplexer 6 multiplexes the coded speech signals from the trunk channels output from the speech coding section 3 , along with the assignment message output from the message generator 5 , and outputs the multiplexed signal to the bearer line. [0028] Next, the operation on the receiving side will be described. [0029] The demultiplexer 7 , receiving a signal including the coded speech signals and the assignment message multiplexed from the bearer line, demultiplexes them, and supplies the assignment message to the message decoder 8 and the coded speech signals to the speech decoder 9 . [0030] To demultiplex the coded speech signals, the demultiplexer 7 refers to the decoding result of the assignment message by the message decoder 8 . [0031] The mess age decoder 8 , receiving the assignment message from the demultiplexer 7 , decodes it and supplies its result to the demultiplexer 7 . It also supplies the speech decoder 9 with the assignment information on the trunk channels and the coding bit rate information. [0032] The speech decoder 9 , receiving the assignment information and coding bit rate information from the message decoder 8 , decodes the coded speech signals output from the demultiplexer 7 with reference to the information, and outputs PCM signals to the trunk side channels. [0033] As described above, the DCME carries out low bit rate coding of the 64-kbit/s PCM signal sent via each trunk channel to an 8-kbit/s, 6.4-kbit/s or 40-kbit/s signal, and transmits the speech activity signals in precedence. Accordingly, it can transmit the telephone speech or facsimile signal efficiently. [0034] Next, let us consider a network configuration as shown in FIG. 12, where such DCMEs are installed at three sites. [0035] During communications between a telephone 110 and a telephone 111 , the speech signal sent from the telephone 110 undergoes low bit rate coding by the DCME 100 , and is decoded by the DCME 101 to a PCM signal. The PCM signal is transferred to a DCME 102 via a circuit switch 106 . The DCME 102 carries out the low bit rate coding of the signal, and transmits it to a DCME 103 . The DCME 103 decodes the low bit rate coded signal to a PCM signal, and sends it to the telephone 111 . Thus, the network configuration as shown FIG. 12 that employs the DCMEs repeats the low bit rate coding and decoding twice, bringing about speech quality degradation. [0036] To avoid such a problem, a technique called tandem passthrough is actually used in such fields as speech ATM communications. [0037] [0037]FIG. 13 is a block diagram showing a configuration of a voice over ATM transmission system with the tandem passthrough function, which is disclosed in Japanese patent application laid-open No. 10-190667. In FIG. 13, the same reference numerals designate the same or like portions to those of FIG. 10, and hence the description thereof is omitted here. [0038] In FIG. 13, the reference numeral 10 designates a cell disassembly section for disassembling ATM cells supplied from the bearer line side and outputting them; 11 designates a pseudo-speech signal generator that converts the 8-kbit/s and 40-kbit/s coded speech signal into a 64-kbit/s pseudo-speech signal that can be handled by the tandem circuit switch without decoding them (for example, the 8-kbit/s coded speech signal is converted into a pseudo 64-kbit/s signal by adding 56-kbit/s dummy data), and that outputs the pseudo-speech signal; and 12 designates a second comfort noise generator for generating comfort noise corresponding to background noise during idle state. [0039] The reference numeral 13 designates a first pattern inserting section for inserting a first pattern signal that causes a party voice over ATM transmission system at the relay to identify that it is a tandem connection; 14 designates a selector for selecting and outputting either the pseudo-speech signal output from the pseudo-speech signal generator 11 or the comfort noise output from the second comfort noise generator 12 ; 15 designates a second pattern inserting section for inserting a second pattern signal that causes the party ATM system at the relay to identify that it is in the tandem switching state by detecting the second pattern signal; and 16 designates a selector for selecting and outputting either the output signal from the first pattern inserting section 13 or the output signal from the second pattern inserting section 15 . [0040] The reference numeral 17 designates a first pattern detector for detecting the first pattern signal sent from the party ATM system at the relay; 18 designates a second pattern detector for detecting the second pattern signal sent from the party ATM system at the relay; 19 designates a transmission bit rate restorer for converting the pseudo-speech signal sent from the circuit switch side into the coded speech signal with original coding bit rate by deleting the 56-kbit/s dummy data from the pseudo-speech signal; 20 designates a selector for selecting and outputting either the coded speech signal output from the speech coding section 3 or the codedspeech signal output from the transmission bit rate restorer 19 ; 21 designates a first comfort noise generator for generating low bit rate coded comfort noise corresponding to background noise in the idle state; 22 designates a selector for selecting and outputting either the low bit rate coded comfort noise output from the first comfort noise generator 21 or the coded speech signal output from the selector 20 ; and 23 designates a cell assembly section for assembling the coded speech signal into ATM cells and for outputting the cells. [0041] The operation of the conventional ATM system as shown in FIG. 13 will now be described assuming that it is utilized in place of the DCME 100 , DCME 101 , DCME 102 and DCME 103 as shown in FIG. 12. [0042] First, the operation of the voice over ATM transmission system used in place of the DCME 102 will be described when communication is conducted between the telephones 112 and 113 in FIG. 12 (in the case of non-tandem connection). [0043] It is assumed in the initial state that the selector 14 selects the output of the pseudo-speech signal generator 11 , the selector 16 selects the output of the first pattern inserting section 13 , the selector 20 selects the output of the speech coding section 3 , and the selector 22 selects the output of the selector 20 , as shown in FIG. 13. [0044] When the tandem circuit switch does not establish a tandem connection, since neither the first pattern detector 17 nor the second pattern detector 18 detects the first pattern signal or the second pattern signal from the output signal of sent from the trunk side, they output a signal indicating a non-detection state. Thus, the selectors 20 , 22 , 14 and 16 maintain their initial states. [0045] Thus, the speech signal path on the transmitting side passes through the speech coding section 3 , selector 20 , selector 22 and cell assembly section 23 , whereas the speech signal path on the receiving side passes through the cell disassembly section 10 , speech decoder 9 , first pattern inserting section 13 and selector 16 so that normal speech coding and decoding are carried out. [0046] In this case, on the path on the receiving side, the first pattern inserting section 13 inserts the first pattern into the PCM signal output from the speech decoder 9 . [0047] The PCM signal output from the speech decoder 9 is a signal obtained by sampling a speech signal waveform at every 125 microseconds and by quantizing the amplitude of the sampled waveform into 8-bit data. Thus, it becomes a 64-kbit/s signal because 8÷125 microseconds=8÷0.000125=64000. [0048] To minimize the degradation in the speech quality due to the first pattern insertion, the first pattern inserting section 13 carries out bit steal of only the LSB (Least Significant Bit) of an 8-bit quantized value at every several sampling interval for the PCM signal, thereby embedding a specified pattern. Thus, the first pattern insertion can implement communications without adding any substantial effect on the quality of the original PCM speech signal waveform. The operation of the voice over ATM transmission system placed at the position of the DCME 103 , which is connected via the bearer line to the voice over ATM transmission system at the site of the DCME 102 , is identical to that of the system placed at the site of the DCME 102 . [0049] Next, the operation of the voice over ATM transmission systems placed at the sites of the DCMEs 101 and 102 will be described when the tandem connection is established in the tandem circuit switch, that is, when the communication is carried out between the telephones 110 and 111 in FIG. 12. [0050] When the voice over ATM transmission systems 60 B and 60 C corresponding to the DCMEs 101 and 102 are connected via the circuit switch 106 as shown in FIG. 14, the first pattern detector 17 of the voice over ATM transmission system 60 B detects the first pattern inserted by the first pattern inserting section 13 of the voice over ATM transmission system 60 C, and likewise the first pattern detector 17 of the voice over ATM transmission system 60 C detects the first pattern inserted by the first pattern inserting section 13 of the voice over ATM transmission system 60 B at the initial stage. [0051] Thus, each of the voice over ATM transmission systems 60 B and 60 C changes its state such that the selector 16 selects the output of the second pattern inserting section 15 , the selector 14 selects the output of the second comfort noise generator 12 and the selector 22 selects the output of the first comfort noise generator 21 . [0052] In each of the voice over ATM transmission systems 60 B and 60 C in this state, the signal path on the receiving side passes through the second comfort noise generator 12 , selector 14 , second pattern inserting section 15 and selector 16 , whereas the signal path on the transmitting side passes through the first comfort noise generator 21 , selector 22 and cell assembly section 23 . [0053] The second comfort noise generator 12 outputs 64-kbit/s PCM comfort noise. The second pattern inserting section 15 inserts the second pattern into the comfort noise (PCM signal) output from the second comfort noise generator 12 . Specifically, the second pattern inserting section 15 carries out bit steal of only the second least significant bit of an 8-bit quantized value at every several sampling interval of the PCM signal to embed a specified pattern such that the second pattern can be distinguished from the first pattern and that the effect on the signal output from comfort noise generator 12 is minimized. [0054] In this way, the voice over ATM transmission systems 60 B and 60 C each send a silent PCM signal including the second pattern to the circuit switch side. On the other hand, the first comfort noise generator 21 outputs a silent signal encoded at the 8 kbit/s bit rate or comfort noise. Accordingly, the voice over ATM transmission systems 60 B and 60 C send the silent signal or comfort noise to the bearer line side. [0055] In the next stage, the voice over ATM transmission systems 60 B and 60 C each receive the silent PCM signal including the second pattern from the circuit switch side. Thus, the second pattern detector 18 detects the second pattern, and outputs a signal indicating its detection. In response to the signal, the selector 20 selects the output of the transmission bit rate restorer 19 . [0056] On the other hand, since the first pattern detector 17 cannot detect the first pattern, it outputs a signal indicating non-detection. In response to the signal, the current state is changed such that the selector 22 selects the output of the selector 20 , and the selector 14 selects the output of the pseudo-speech signal generator 11 . [0057] As for the state of the selector 16 , it maintains selecting the output of the second pattern inserting section 15 to be output. The pseudo-speech signal generator 11 generates the 64-kbit/s pseudo-speech signal by adding dummy data to the 8-kbit/s coded speech signal supplied from the cell disassembly section 10 . The second pattern inserting section 15 inserts the second pattern to a part of the pseudo-speech signal. In this case, the pseudo-speech signal is assembled such that its part corrupted by inserting the second pattern becomes the dummy data. Thus, the 8-kbit/s coded speech signal is output without any problem. [0058] The transmission bit rate restorer 19 , receiving the pseudo-speech signal, extracts the 8-kbit/s coded speech signal and supplies it to the selector 20 . The operation described above can implement the passthrough operation because the coded speech signal disassembled by the cell disassembly section 10 of the ATM transmission system 60 B arrives at the cell assembly section 23 of the voice over ATM transmission system 60 C, and reversely the coded speech signal disassembled by the cell disassembly section 10 of the ATM transmission system 60 C arrives at the cell assembly section 23 of the voice over ATM transmission system 60 B. [0059] Applying the tandem passthrough function to the DCME as shown in FIG. 10 makes it possible for a link including the plurality of DCMEs to transmit telephone speech without degrading the speech quality. [0060] With the foregoing configuration, the conventional digital circuit multiplication equipment has the following problems when the tandem passthrough function is applied to the variable bit rate DCME. [0061] Let us consider a case, for example, where the telephone 110 communicates with the telephone 111 in FIG. 12, and the tandem passthrough operation is implemented by transmitting the speech signal through a trunk channel between the DCME 101 and the DCME 102 . Here, the bearer line assignment from the DCME 100 to the DCME 101 can be changed depending on the speech activity/silence state, signal discrimination state and bearer load state detected by the DCME 100 . For example, an increase in the bearer line load can change the speech coding bit rate of the speech signal sent from the telephone 110 from 8 kbits/s to 6.4 kbits/s. In this case, the DCME 101 can notify the DCME 102 of the change by embedding the speech activity/silence information and speech coding bit rate information into the pseudo-speech signal transmitted from the DCME 101 to the DCME 102 . [0062] It is also possible for the DCME 102 to determine the assignment of the trunk channel to the bearer line in accordance with the speech coding bit rate information and speech activity/silence information embedded into the pseudo-speech signal, and transmits information about the assignment to the DCME 103 . However, it is not always possible for the DCME 102 to carry out the assignment to the bearer line as required by the speech coding bit rate information and speech activity/silence information embedded in the pseudo-speech signal, depending on the load condition of the bearer line to which the DCME 102 transmits the signal. [0063] For example, if all the trunk channels connected to the bearer line are in speech activity state, and hence occupy the bearer line, even if a request arrives to change from 6.4 kbits/s to 8 kbits/s, the assignment change to the 8-kbit/s is detained, maintaining the 6.4-kbit/s state. Such a bit rate mismatch can also take place because the message number is limited. When such a mismatch takes place between the actual transmission bit rate of the coded speech signal and the assigned transmission bit rate on the bearer line, the speech decoder 9 cannot be provided with correct coding bit rate information, bringing about serious speech quality degradation. [0064] As described above, implementing the tandem passthrough function by the variable bit rate DCME unavoidably involves a mismatch between the actual transmission bit rate of the coded speech signal and the assigned transmission bit rate on the bearer line, which presents a problem of degrading the speech quality seriously because the correct coding bit rate information cannot be supplied to the speech decoder. SUMMARY OF THE INVENTION [0065] The present invention is implemented to solve the foregoing problem. It is therefore an object of the present invention to provide digital circuit multiplication equipment capable of implementing high quality transmission by preventing speech quality degradation. [0066] According to a first aspect of the present invention, there is provided digital circuit multiplication equipment having a tandem passthrough function of carrying out passthrough transmission of a coded speech signal, and a variable bit rate function of varying a transmission bit rate of the coded speech signal in accordance with a load on the equipment, the digital circuit multiplication equipment comprising: dummy data adding means for generating a pseudo-speech signal with a predetermined transmission bit rate by adding dummy data including coding bit rate information to a coded speech signal supplied from a transmission line, and for supplying the pseudo-speech signal to a tandem circuit switch; speech signal extracting means for extracting a coded speech signal from a pseudo-speech signal supplied from the tandem circuit switch; bit rate identification information adding means for adding bit rate identification information to the coded speech signal extracted by the speech signal extracting means; and speech signal output means for selecting, with reference to coding bit rate information included in the pseudo-speech signal, one of the coded speech signal extracted by the speech signal extracting means and the coded speech signal including the bit rate identification information added by the bit rate identification information adding means, and for delivering the selected coded speech signal to the transmission line. [0067] Here, the digital circuit multiplication equipment may further comprise load measuring means for measuring a load imposed on the equipment, wherein the speech signal output means may carry out the selection of the coded speech signal only when the load on the equipment exceeds a predetermined threshold value. [0068] The load measuring means may consist of a message number supervisor for measuring a number of messages on a message channel assigned to the transmission line. [0069] The load measuring means may consist of a speech activity channel number supervisor for measuring a number of trunk channels in a speech active state. [0070] The load measuring means may consist of a bearer occupancy rate supervisor for measuring a bearer occupancy rate of the transmission line. [0071] The digital circuit multiplication equipment may further comprise information reduction means for reducing information amount of the coded speech signal extracted by the speech signal extracting means, wherein the speech signal output means may select one of three coded speech signals consisting of the coded speech signal extracted by the speech signal extracting means, the coded speech signal including the bit rate identification information added by the bit rate identification information adding means, and the coded speech signal whose information amount by the information reduction means. [0072] According to a second aspect of the present invention, there is provided a digital circuit multiplication equipment having a tandem passthrough function of carrying out passthrough transmission of a coded speech signal, and a variable bit rate function of varying a transmission bit rate of the coded speech signal in accordance with a load on the equipment, the digital circuit multiplication equipment comprising: message notifying means for supplying a transmission line with amessage indicating a trunk channel in a passthrough state; and bit rate fixing means for fixing, when receiving a message indicating a trunk channel in a passthrough state from the transmission line, a transmission bit rate of a coded speech signal on the trunk channel indicated by the message to a predetermined bit rate. [0073] Here, when the message notifying means outputs the message, it may utilize a bearer channel number in a message channel assigned to the transmission line. [0074] When the message notifying means outputs the message, it may utilize a trunk channel number in a message channel assigned to the transmission line. [0075] According to a third aspect of the present invention, there is provided a digital circuit multiplication equipment having a tandem passthrough function of carrying out passthrough transmission of a coded speech signal, and a variable bit rate function of varying a transmission bit rate of the coded speech signal in accordance with a load on the equipment, the digital circuit multiplication equipment comprising: detecting means for detecting a start of a passthrough operation of a trunk channel; assignment means for assigning the trunk channel that starts the passthrough operation to one of a passthrough clique and a bit bank; and speech signal output means for transmitting a coded speech signal on the trunk channel through one of the passthrough clique and the bit bank assigned by the assignment means. [0076] Here, the clique may consist of a series of data sequences consisting of a message channel and a plurality of bearer channels, and the bit bank may consist of a series of data sequences forming a dedicated transmission line using a plurality of bearer channels. BRIEF DESCRIPTION OF THE DRAWINGS [0077] [0077]FIG. 1 is a block diagram showing a configuration of an embodiment 1 of the digital circuit multiplication equipment in accordance with the present invention; [0078] [0078]FIG. 2 is a block diagram showing a configuration of an embodiment 2 of the digital circuit multiplication equipment in accordance with the present invention; [0079] [0079]FIG. 3 is a block diagram showing a configuration of an embodiment 3 of the digital circuit multiplication equipment in accordance with the present invention; [0080] [0080]FIG. 4 is a schematic diagram illustrating structures of cliques; [0081] [0081]FIG. 5 is a block diagram showing a configuration of an embodiment 4 of the digital circuit multiplication equipment in accordance with the present invention; [0082] [0082]FIG. 6 is a block diagram showing a configuration of an embodiment 5 of the digital circuit multiplication equipment in accordance with the present invention; [0083] [0083]FIG. 7 is a block diagram showing a configuration of an embodiment 6 of the digital circuit multiplication equipment in accordance with the present invention; [0084] [0084]FIG. 8 is a block diagram showing a configuration of an embodiment 7 of the digital circuit multiplication equipment in accordance with the present invention; [0085] [0085]FIG. 9 is a block diagram showing a configuration of an embodiment 8 of the digital circuit multiplication equipment in accordance with the present invention; [0086] [0086]FIG. 10 is a block diagram showing a configuration of a conventional variable bit rate DCME; [0087] [0087]FIG. 11 is a schematic diagram illustrating a frame structure of a signal a DCME supplies to a bearer line; [0088] [0088]FIG. 12 is a block diagram showing a configuration of a network system; [0089] [0089]FIG. 13 is a block diagram showing a configuration of a conventional voice over ATM transmission system with a tandem passthrough function; [0090] [0090]FIG. 14 is a block diagram showing an example of connection between a circuit switch and the conventional voice over ATM transmission systems; and [0091] [0091]FIG. 15 is a diagram illustrating examples of a coded speech signal output from a transmission bit rate restorer 19 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0092] The invention will now be described with reference to the accompanying drawings. [0093] Embodiment 1 [0094] [0094]FIG. 1 is a block diagram showing a configuration of an embodiment 1 of the digital circuit multiplication equipment in accordance with the present invention. In FIG. 1, the same reference numerals designate the same or like portions to those of FIGS. 10 and 13. The basic structure and operation of the digital circuit multiplication equipment as shown in FIG. 1 are described in Japanese patent application laid-open No. 10- 190667 , which is incorporated herein by reference. [0095] In FIG. 1, the reference numeral 1 designates a speech activity detecting section for receiving a PCM signal and for making a decision as to whether the input signal from each trunk channel is in speech active state or not; 2 designates a signal discriminating section for receiving the PCM signal and for deciding as to whether the input signal to each trunk channel is a telephone speech or a data signal like a facsimile signal; 3 designates a speech coding section for encoding the PCM signal and outputting a coded speech signal; 4 designates an assignment controller for assigning transmission bit rate of each trunk channel to bearer lines in accordance with the decision result of the speech activity detecting section 1 and the discrimination result of the signal discriminating section 2 ; 5 designates a message generator for generating an assignment message in accordance with the assignment result of the assignment controller 4 ; and 6 designates a multiplexer for multiplexing, in accordance with the assignment result fed from the assignment controller 4 , the coded speech signals of the individual trunk channels output from the speech coding section 3 , along with the assignment message generated by the message generator 5 , to be output to the bearer line. [0096] The reference numeral 7 designates a demultiplexer that demultiplexes a signal from the bearer line including the coded speech signals and the assignment message multiplexed, and supplies the assignment message to a message decoder 8 and the coded speech signal to a speech decoder 9 and a pseudo-speech signal generator 11 ; 8 designates the message decoder that decodes the assignment message supplied from the demultiplexer 7 and supplies the decoded result to the demultiplexer 7 , and the assignment information and coding bit rate information on the individual trunk channels to the speech decoder 9 and a pseudo-speech signal control information inserting section 33 ; and 9 designates the speech decoder that decodes the coded speech signal supplied from the demultiplexer 7 in accordance with the assignment information and coding bit rate information supplied from the message decoder 8 , and outputs the resultant PCM signal. [0097] The reference numeral 11 designates a pseudo-speech signal generator that converts the 8-kbit/s and 40-kbit/s coded speech signal into a 64-kbit/s pseudo-speech signal that can be handled by the tandem circuit switch without decoding them; 12 designates a second comfort noise generator for generating comfort noise corresponding to background noise in the idle state; and 33 designates a pseudo-speech signal control information inserting section for inserting the speech activity/silence information and coding bit rate information into the pseudo-speech signal. The pseudo-speech signal generator 11 and pseudo-speech signal control information inserting section 33 constitute a dummy data adding means. [0098] The reference numeral 13 designates a first pattern inserting section for inserting a first pattern signal that causes a party DCME at the relay to identify that it is a tandem connection; 14 designates a selector for selecting and outputting either the pseudo-speech signal output from the pseudo-speech signal control signal inserting section 33 or the comfort noise output from the second comfort noise generator 12 ; 15 designates a second pattern inserting section for inserting a second pattern signal that causes the party DCME at the relay to identify that it is in the tandem switching state by detecting the second pattern signal by the DCME; and 16 designates a selector for selecting and outputting either the output signal from the first pattern inserting section 13 or the output signal from the second pattern inserting section 15 . [0099] The reference numeral 17 designates a first pattern detector for detecting the first pattern signal sent from the party DCME at the relay; 18 designates a second pattern detector for detecting the second pattern signal sent from the party DCME at the relay; 19 designates a transmission bit rate restorer for converting the pseudo-speech signal sent from the circuit switch side into the coded speech signal with the original coding bit rate by deleting the 56-kbit/s dummy data from the pseudo-speech signal; 30 designates a coding bit rate information adding section (bit rate identification information adding means) for adding the bit rate identification information to the coded speech signal extracted by the transmission bit rate restorer 19 ; 31 designates a pseudo-speech signal control information extracting section for extracting the speech activity/silence information and coding bit rate information included in the pseudo-speech signal; and 32 designates a selector for selecting and outputting-, under the control of the assignment controller 4 , either the coded speech signal extracted by the transmission bit rate restorer 19 or the coded speech signal including the bit rate identification information added by the coding bit rate information adding section 30 . [0100] The reference numeral 20 designates a selector for selecting and outputting either the coded speech signal output from the speech coding section 3 or the coded speech signal output from the selector 32 ; 21 designates a first comfort noise generator for generating low bit rate coded comfort noise corresponding to background noise in the idle state; and 22 designates a selector for selecting and outputting either the low bit rate coded comfort noise output from the first comfort noise generator 21 or the coded speech signal output from the selector 20 . [0101] The assignment controller 4 , selectors 20 , 22 and 32 and multiplexer 6 constitute a speech signal output means. [0102] Next, the operation of the present embodiment 1 will be described. [0103] For example, the operation of the variable bit rate DCMEs with transmission bit rates of 8 kbits/s and 6.4 kbits/s will be described (it is assumed here that the bearer line interconnecting the DCME 100 and DCME 101 as shown in FIG. 12 is assigned 8-kbit/s or 6.4-kbits/s transmission bit rate). [0104] The pseudo-speech signal generator 11 of the DCME 101 as shown in FIG. 12 adds 56-kbit/s dummy data to the coded speech signal when the demultiplexer 7 outputs an 8-kbit/s coded speech signal. In contrast, when the demultiplexer 7 outputs a 6.4-kbit/s coded speech signal, it adds 57.6-kbit/s dummy data to the coded speech signal. Thus, it generates a pseudo-speech signal with a 64-kbit/s transmission bit rate. [0105] When the pseudo-speech signal generator 11 generates the pseudo-speech signal with the 64-kbit/s transmission bit rate, the pseudo-speech signal control information inserting section 33 inserts the pseudo-speech signal control information such as speech activity/silence information and coding bit rate information into the pseudo-speech signal. In other words, it replaces a part of the dummy data added by the pseudo-speech signal generator 11 by the pseudo-speech signal control information. The replacement is carried out by replacing the data at a predetermined position by data with a predetermined pattern. For example, the speech activity/silence information indicating the speech activity or silence is stored in the nth bit of the dummy data, and the coding bit rate information is stored from the (n+1)th bit. Incidentally, the pseudo-speech signal control information is not limited to the above. For example, it can consist of a single data pattern representing a combination of the speech activity/silence information and the coding bit rate information. [0106] On the other hand, the transmission bit rate restorer 19 in the DCME 102 of FIG. 12 eliminates the 56-kbit/s dummy data from the pseudo-speech signal sent from the circuit switch side, thereby converting the pseudo-speech signal to the coded speech signal with the original coding bit rate. [0107] When the original coding bit rate is 6.4 kbits/s, the coding bit rate information adding section 30 adds bit rate identification information (information indicating that the coding bit rate is 6.4 kbits/s) to the coded speech signal extracted by the transmission bit rate restorer 19 to convert it to the coded speech signal with the 8-kbit/s transmission bit rate. [0108] [0108]FIG. 15 is a diagram illustrating the coded speech signal output from the transmission bit rate restorer 19 . FIG. 15( a ) illustrates one frame of the coded speech signal with a transmission rate of 8 kbit/s. The frame consists of LP (line spectrum pairs), P 1 and P 2 (adaptive codebook), P 0 (parity), C 1 and C 2 (fixed codebook) and G 1 and G 2 (codebook gains), which amount to 80 bits. On the other hand, FIG. 15( b ) illustrates one frame of the coded speech signal with a transmission rate of 6.4 kbit/s. It has a frame structure similar to that of FIG. 15( a ), except that C 1 and C 2 are reduced from 17 bits to 11 bits, each. Thus, their data amount is reduced as compared with that of FIG. 15( a ) with the transmission rate of 8 kbit/s. [0109] The coding bit rate information adding section 30 adds the bit rate identification information to the 6.4 kbit/s. For example, a frame consisting of 80 bits is created by inserting 16-bit bit rate identification information S 1 (“1111 1111 1111 1111”, for example) between the LP and P 1 as illustrated in FIG. 15( c ). The position of inserting the bit rate identification information S 1 is not limited to this position. For example, it can be inserted at any of the initial, middle or final position of the frame. Besides, the 16-bit data can be any data as long as it can be identified. [0110] The pseudo-speech signal control information extracting section 31 extracts the pseudo-speech signal control information such as the speech activity/silence information and coding bit rate information, and supplies it to the assignment controller 4 . The pseudo-speech signal control information is extracted by reading data from a predetermined position of the dummy data. [0111] Thus, referring to the coding bit rate information to find that the trunk channel in the passthrough state is in the speech activity state, the assignment controller 4 supplies the message generator 5 and multiplexer 6 with a command to assign 8 kbits/s to the bearer line. [0112] When the transmission bit rate of the coded speech signal contained in the pseudo-speech signal is 8 kbits/s, the assignment controller 4 supplies the selector 32 with a command to select the coded speech signal output from the transmission bit rate restorer 19 . [0113] When the channel in the passthrough state is in the silent state, no assignment to the bearer line is carried out. [0114] In the DCME 103 of FIG. 12, the speech decoder 9 decodes the coded speech signal, and supplies the PCM signal to the circuit switch 105 . [0115] In this case, even when the speech decoder 9 receives the 8-kbit/s coded speech signal, if it includes the bit rate identification information (information indicating that the coding bit rate is 6.4 kbits/s), the speech decoder 9 carries out 6.4-kbit/s decoding. In contrast, when the coded speech signal includes no bit rate identification information, it carries out 8-kbit/s decoding. [0116] The operation of the foregoing DCMEs will now be described on the path from the telephone 110 to the telephone 111 as shown in FIG. 12. [0117] When the DCME 100 transmits an 8-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 8-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0118] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, assigns the trunk channel to the bearer line for the DCME 103 at a bit rate of 8 kbits/s, and supplies the bearer line with the coded speech signal with the coding bit rate information, which is output from the coding bit rate information adding section 30 . In other words, the assignment controller 4 controls the selector 32 such that the selector 32 outputs the output data of the coding bit rate information adding section 30 in response to the coding bit rate information in the dummy data. [0119] Thus, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s coded speech signal. [0120] The DCME 103 decodes the 8-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0121] In contrast, when the DCME 100 transmits a 6.4-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 6.4-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0122] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, assigns the trunk channel to the bearer line for the DCME 103 at a bit rate of 8 kbits/s, and supplies the bearer line with the coded speech signal with coding bit rate information output from the coding bit rate information adding section 30 . [0123] Thus, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s signal consisting of the 6.4-kbit/s coded speech signal plus the coding bit rate information. [0124] The DCME 103 recognizes the 6.4-kbit/s coded speech signal from the coding bit rate information added to the 8-kbit/s signal, decodes it into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0125] In this way, the assignment to the bearer line in the second link on the tandem passthrough is carried out at 8 kbits/s. In this case, when the coded speech signal is 6.4 kbits/s, the information indicating that the coding bit rate is 6.4 kbits/s is added to the 6.4-kbit/s coded speech signal to handle it as the signal with the 8-kbit/s transmission bit rate. Thus, the present embodiment 1 can implement high quality transmission without degrading the speech quality in the variable bit rate DCME with the tandem passthrough function. [0126] Embodiment 2 [0127] [0127]FIG. 2 is a block diagram showing a configuration of an embodiment 2 of the digital circuit multiplication equipment in accordance with the present invention. In FIG. 2, the same reference numerals designate the same or like portions to those of FIG. 1, and hence the description thereof is omitted here. [0128] In FIG. 2, the reference numeral 34 designates a tandem notification message generator (message notifying means) for supplying the bearer line with a message indicating trunk channels in a passthrough operation state. Receiving the message from the tandem notification message generator 34 of the party DCME, the assignment controller 4 constituting a bit rate fixing means fixes the transmission bit rate of the coded speech signal of the trunk channel indicated by the message, by setting the coding bit rate assigned to the trunk channel at 8 kbits/s. [0129] Next, the operation of the present embodiment 2 will be described. [0130] For example, the operation of the variable bit rate DCMEs with transmission bit rates of 8 kbits/s and 6.4 kbits/s will be described. [0131] When the tandem notification message generator 34 in the DCME 101 in FIG. 12 is supplied with the second pattern detection signal indicating that the trunk channel enters the passthrough state from the second pattern detector 18 , it generates a message for notifying the party DCME of the start of the passthrough operation of the trunk channel. [0132] The message is supplied to the multiplexer 6 from the message generator 5 to be output to the bearer line and sent to the party DCME 100 . [0133] The assignment controller 4 in the DCME 100 , receiving the message via the demultiplexer 7 and message decoder 8 , carries out control such that it assigns only the coding bit rate of 8 kbits/s to the trunk channel indicated by the message without assigning the coding bit rate of 6.4 kbits/s, through the DSI processing is carried out as before. [0134] As described before in connection with FIG. 11, each message consists of a combination of the TC number and BC number, and the available BC numbers are from 1 to 248. In view of this, the BC number 249 is used as the passthrough operation start message. For example, a message TC number=n and BC number=249 means that the trunk channel n starts the passthrough operation. The BC number=250 is used as a pass through operation end message. [0135] When the tandem notification message generator 34 receives a second pattern non-detection signal indicating that the passthrough state of the trunk channel is released from the second pattern detector 18 , it outputs a message indicating the end of the passthrough operation. Receiving the message indicating the end of the passthrough operation, the assignment controller 4 of the party DCME returns to its normal operation. [0136] The operation of the DCMEs will now be described on the path from the telephone 110 to the telephone 111 in FIG. 12. [0137] First, when the DCME 101 recognizes that a trunk channel is in the passthrough state, it sends the passthrough start message to the DCME 100 . [0138] When the DCME 100 receives the message, the assignment controller 4 controls such that it assigns only the coding bit rate of 8 kbits/s to the trunk channel. Thus, only the 8-kbit/s speech coding is applied to the trunk channel from the DCME 100 to the DCME 101 . [0139] The DCME 101 generates the 64-kbit/s pseudo-speech signal by adding dummy data including the pseudo-speech signal control information to the 8-kbit/s coded speech signal, and sends the pseudo-speech signal to the DCME 102 via the circuit switch 106 . [0140] The DCME 102 , which knows that the trunk channel is in the passthrough state, assigns the trunk channel to the bearer line for the DCME 103 at the bit rate of 8 kbits/s, and selects and outputs the coded speech signal output from the transmission bit rate restorer 19 . [0141] As a result, the bearer line for the DCME 103 is assigned the 8-kbit/s transmission bit rate, and transmits the 8-kbit/s coded speech signal. [0142] The DCME 103 decodes the 8-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0143] In this way, the present embodiment 2 notifies the party DCME 100 that the trunk channel is in the tandem passthrough state, and the party DCME controls such that the trunk channel is brought into the fixed bit rate. Thus, the present embodiment 2 can implement high quality transmission without degrading the speech quality in the variable bit rate DCME with the tandem passthrough function. [0144] Although the non-used BC numbers are utilized as the passthrough operation start and end messages, this is not essential. For example, non-used TC numbers can be utilized instead. Since the number of the trunk channels accommodated by the DCME is 600 channels, the TC numbers=601 and 602 are not used for the bearer line assignment message. Therefore, the message TC number=601 and BC number=m can indicate that the trunk channel currently connected to the mth BC starts the passthrough operation, whereas the message TC number=602 and BC number=m can indicate that the trunk channel currently connected to the mth BC terminates the passthrough operation, offering a similar advantage to that described above. [0145] Embodiment 3 [0146] [0146]FIG. 3 is a block diagram showing a configuration of an embodiment 3 of the digital circuit multiplication equipment in accordance with the present invention. In FIG. 3, the same reference numerals designate the same or like portions to those of FIG. 1, and hence the description thereof is omitted here. [0147] In FIG. 3, the reference numeral 35 designates a first message generator for carrying out message processing onto a first clique, and 36 designates a second message generator for carrying out message processing onto a second clique. [0148] Next, the operation of the present embodiment 3 will be described. [0149] For example, the operation of the variable bit rate DCMEs with transmission bit rates of 8 kbits/s and 6.4 kbits/s will be described. [0150] The assignment controller 4 , receiving the second pattern detection signal indicating that a particular trunk channel enters the passthrough state from the second pattern detector 18 , recognizes that the trunk channel starts the passthrough operation, and supplies the second message generator 36 and multiplexer 6 with a command to assign the trunk channel to a second clique (passthrough clique). [0151] Thus, the coded speech signal on the trunk channel is transmitted to the party DCME through the second clique. Here, the clique refers to a series of data sequences each consisting of the message channel and bearer channels as illustrated in FIG. 11. The detail of the clique is described in the ITU-T recommendation G.763. Using the second clique means that two cliques share a single bearer line. For example, it can be implemented as illustrated in FIG. 4, where the first clique utilizes a bearer frame from its initial position, whereas the second clique utilizes it from its final position. The DCME that receives the two cliques decodes the message of each clique, and allots the data on the bearer channel to the trunk channels in accordance with the decoded message. [0152] The operation of the foregoing DCMEs will now be described on the path from the telephone 110 to the telephone 111 as shown in FIG. 12. [0153] When the DCME 100 transmits an 8-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 8-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0154] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, assigns the trunk channel to the second clique on the bearer line for the DCME 103 at a bit rate of 8 kbits/s, and selects and outputs the coded speech signal output from the transmission bit rate restorer 19 . [0155] As a result, the trunk channel in the passthrough state is assigned to the bearer line for the DCME 103 at the transmission bit rate of 8 kbits/s, so that the bearer line transmits the 8-kbit/s coded speech signal. [0156] The DCME 103 decodes the 8-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0157] In contrast, when the DCME 100 transmits a 6.4-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 6.4-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0158] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, assigns the trunk channel to the second clique on the bearer line for the DCME 103 at a bit rate of 6.4 kbits/s, and selects and outputs the coded speech signal output from the transmission bit rate restorer 19 . [0159] As a result, the trunk channel in the passthrough state is assigned to the bearer line for the DCME 103 at the transmission bit rate of 6.4-kbit/s, so that the bearer line transmits the 6.4-kbit/s coded speech signal. [0160] The DCME 103 decodes the 6.4-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0161] Thus transmitting the trunk channel in the tandem passthrough state by the second clique enables the assignment, which is required by the speech coding information and speech activity/silence information sent from the first link, to be implemented without detaining the request. Thus, the present embodiment 3 can implement high quality transmission without degrading the speech quality in the variable bit rate DCME with the tandem passthrough function. [0162] Embodiment 4 [0163] [0163]FIG. 5 is a block diagram showing a configuration of an embodiment 4 of the digital circuit multiplication equipment in accordance with the present invention. In FIG. 5, the same reference numerals designate the same or like portions to those of FIG. 1, and hence the description thereof is omitted here. [0164] In FIG. 5, the reference numeral 37 designates a bit bank generator for generating a bit bank; and 38 designates a bit bank decoder for decoding the data sequence in the bit bank, and for controlling the demultiplexer 7 , speech decoder 9 , pseudo-speech signal generator 11 and pseudo-speech signal control information inserting section 33 in the same manner as controlling the message decoder 8 , for the data in the bit bank. [0165] Next, the operation of the present embodiment 4 will be described. [0166] For example, the operation of the variable bit rate DCMEs with transmission bit rates of 8 kbits/s and 6.4 kbits/s will be described. [0167] The assignment controller 4 , receiving the second pattern detection signal indicating that a particular trunk channel enters the passthrough state from the second pattern detector 18 , recognizes that the trunk channel starts the passthrough operation, and supplies the bit bank generator 37 and multiplexer 6 with a command to assign the trunk channel to the bit bank. [0168] Thus, the coded speech signal on the trunk channel is transmitted to the party DCME through the bit bank. Here, the bit bank refers to a series of data sequences that form a dedicated transmission line using a plurality of bearer channels as illustrated in FIG. 11, and transmits the target data therein. The detail of the clique is described in the ITU-T recommendation G.763. A single bit bank can transmit data of a plurality of trunk channels. For example, a 40-kbit/s bit bank using five 8-kbit/s bearer channels can transmit four channel 10-kbit/s data sequences, each consisting of an 8-kbit/s coded speech signal and 2-kbit/s control information. [0169] To increase or decrease the capacity of the bit bank, the assignment message to the DCME is used. Reserving a large capacity bit bank in advance can facilitate the assignment of the passthrough channels to the bit bank. In the DCME that receives the bit bank, the demultiplexer 7 supplies the bit bank data to the bit bank decoder 38 according to the decoded result by the message decoder 8 , and delivers the coded speech signal of each trunk channel to the speech decoder 9 and pseudo-speech signal generator 11 of the trunk channel according to the decoded result by the bit bank decoder 38 . As for the message decoding of the bit band decoder 38 , and the control of the speech decoder 9 and the like, the well-known method and control can be utilized which are similar to the decoding method of the bit bank decoder 38 and the control method. [0170] The operation of the foregoing DCMEs will now be described on the path from the telephone 110 to the telephone 111 as shown in FIG. 12. [0171] When the DCME 100 transmits an 8-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 8-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0172] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, assigns the trunk channel to the bit bank on the bearer line for the DCME 103 , and selects and outputs the coded speech signal output from the transmission bit rate restorer 19 . Here, the assignment controller 4 assigns the trunk channel to the bit bank, and controls the bit bank generator 37 such that the bit bank generator 37 generates the bit bank by using the data of the trunk channel. As for generating the bit bank, the well-known technique described in the ITU-T recommendation G.763 can be utilized. [0173] As a result, the trunk channel in the passthrough state is assigned to the bit bank on the bearer line for the DCME 103 , so that the bit bank transmits the 8-kbit/s coded speech signal. [0174] The DCME 103 decodes the 8-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0175] In contrast, when the DCME 100 transmits a 6.4-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 6.4-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0176] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, assigns the trunk channel to the bit bank on the bearer line for the DCME 103 , and selects and outputs the coded speech signal output from the transmission bit rate restorer 19 . [0177] As a result, the trunk channel in the passthrough state is assigned to the bit bank on the bearer line for the DCME 103 , so that the bit bank transmits the 6.4-kbit/s coded speech signal. [0178] The DCME 103 decodes the 6.4-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0179] Thus transmitting the trunk channel in the tandem passthrough state by the bit bank collecting the data of the tandem passthrough channels enables the assignment, which is required by the speech coding information and speech activity/silence information sent from the first link, to be implemented without detaining the request. Thus, the present embodiment 4 can implement high quality transmission without degrading the speech quality in the variable bit rate DCME with the tandem passthrough function. [0180] Embodiment 5 [0181] [0181]FIG. 6 is a block diagram showing a configuration of an embodiment 5 of the digital circuit multiplication equipment in accordance with the present invention. In FIG. 6, the same reference numerals designate the same or like portions to those of FIG. 1, and hence the description thereof is omitted here. [0182] In FIG. 6, the reference numeral 39 designates a message number supervisor for supervising the number of messages generated by the message generator 5 . [0183] Next, the operation of the present embodiment 5 will be described. [0184] For example, the operation of the-variable bit rate DCMEs with transmission bit rates of 8 kbits/s and 6.4 kbits/s will be described. [0185] The message number supervisor 39 monitors the number of messages generated by the message generator 5 . When the number of messages is small, the load on the DCME is light, and hence the assignment to the bearer line, which is requested by the speech coding bit rate information and speech activity/silence information sent from the first link, can be carried out without detaining the request. However, when the number of messages generated is large, the load on the DCME is heavy, and hence the request is not always carried out soon. [0186] In view of this, the message number supervisor 39 has a particular threshold value, and when the number of message generated exceeds the threshold value, it supplies the assignment controller 4 with a command to assign the passthrough state trunk channel to the bearer line at 8 kbits/s in the second link as in the foregoing embodiment 1. In contrast, when the number of messages generated is equal to or less than the threshold value, it provides the assignment controller 4 with a command to assign the bit rate of 8 kbits/s or 6.4 kbits/s to the bearer line in accordance with the request from the first link. [0187] The operation of the foregoing DCMEs will now be described on the path from the telephone 110 to the telephone 111 as shown in FIG. 12. [0188] When the DCME 100 transmits an 8-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 8-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0189] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, has the assignment controller 4 decide the transmission bit rate to be assigned to the bearer line in accordance with the supervisory result of the message number supervisor 39 . [0190] When the number of messages is equal to or less than the threshold value, the assignment controller 4 decides the transmission bit rate to be assigned to the bearer-line in accordance with the information output from the pseudo-speech signal control information extracting section 31 . In this case, since the information output from the pseudo-speech signal control information extracting section 31 indicates that the coded speech signal included in the pseudo-speech signal of the trunk channel is 8 kbits/s, the assignment controller 4 assigns the 8 kbits/s to the bearer line. In addition, it controls such that the coded speech signal output from the transmission bit rate restorer 19 is selected and output. [0191] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s coded speech signal. [0192] The DCME 103 decodes the 8-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0193] When the number of messages exceeds the threshold value, the assignment controller 4 always assigns the trunk channel to the bearer line for the DCME 103 at the bit rate of 8 kbits/s without considering the information output from the pseudo-speech signal control information extracting section 31 , and controls such that the coded speech signal output from the transmission bit rate restorer 19 is selected and output. [0194] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s coded speech signal. [0195] The DCME 103 decodes the 8-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0196] In contrast, when the DCME 100 transmits a 6.4-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 6.4-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0197] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, has the assignment controller 4 decide the transmission bit rate to be assigned to the bearer line in accordance with the supervisory result of the message number supervisor 39 . [0198] When the number of messages is equal to or less than the threshold value, the assignment controller 4 decides the transmission bit rate to be assigned to the bearer line in accordance with the information output from the pseudo-speech signal control information extracting section 31 . In this case, since the information output from the pseudo-speech signal control information extracting section 31 indicates that the coded speech signal included in the pseudo-speech signal of the trunk channel is 6.4 kbits/s, the assignment controller 4 assigns the 6.4 kbits/s to the bearer line. In addition, it controls such that the coded speech signal output from the transmission bit rate restorer 19 is selected and output. [0199] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 6.4 kbits/s, so that it transmits the 6.4-kbit/s coded speech signal. [0200] The DCME 103 decodes the 6.4-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0201] When the number of messages exceeds the threshold value, the assignment controller 4 always assigns the trunk channel to the bearer line for the DCME 103 at the bit rate of 8 kbits/s without considering the information output from the pseudo-speech signal control information extracting section 31 , and controls such that the coded speech signal output from the coding bit rate information adding section 30 is selected and output. [0202] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s signal including the 6.4-kbit/s coded speech signal plus the coding bit rate information. [0203] The DCME 103 recognizes the 6.4-kbit/s coded speech signal from the coding bit rate information added to the 8-kbit/s signal, decodes it into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0204] Thus controlling the bit rate assigned to the bearer line in the second link in accordance with the number of messages generated, the present embodiment 5 can implement high quality and low bit rate transmission without degrading the speech quality in the variable bit rate DCME with the tandem passthrough function. [0205] Embodiment 6 [0206] [0206]FIG. 7 is a block diagram showing a configuration of an embodiment 6 of the digital circuit multiplication equipment in accordance with the present invention. In FIG. 7, the same reference numerals designate the same or like portions to those of FIG. 1, and hence the description thereof is omitted here. [0207] In FIG. 7, the reference numeral 40 designates a speech activity channel number supervisor for monitoring the number of trunk channels in the speech active state. [0208] Next, the operation of the present embodiment 6 will be described. [0209] For example, the operation of the variable bit rate DCMEs with transmission bit rates of 8 kbits/s and 6.4 kbits/s will be described. [0210] The speech activity channel number supervisor 40 monitors the number of the trunk channels in the speech active state in accordance with the decision result by the speech activity detecting section 1 . When the number of the trunk channels in the speech active state is small, the load on the DCME is light, and hence the assignment to the bearer line, which is requested by the speech coding bit rate information and speech activity/silence information sent from the first link, can be carried out without detaining the request. On the other hand, when the number of the trunk channels in the speech active state is large, the load on the DCME is heavy, and hence the request is not always carried out soon. [0211] In view of this, the speech activity channel number supervisor 40 has a particular threshold value, and when the number of the trunk channels in the speech active state exceeds the threshold value, it supplies the assignment controller 4 with a command to assign the passthrough state trunk channel to the bearer line at 8 kbits/s in the second link as in the foregoing embodiment 1. In contrast, when the number of the trunk channels in the speech active state is equal to or less than the threshold value, it provides the assignment controller 4 with a command to assign the bit rate of 8 kbits/s or 6.4 kbits/s to the bearer line in accordance with the request from the first link. [0212] The operation of the foregoing DCMEs will now be described on the path from the telephone 110 to the telephone 111 as shown in FIG. 12. [0213] When the DCME 100 transmits an 8-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 8-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0214] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, has the assignment controller 4 decide the transmission bit rate to be assigned to the bearer line in accordance with the supervisory result of the speech activity channel number supervisor 40 . [0215] When the number of the trunk channels in the speech active state is equal to or less than the threshold value, the assignment controller 4 decides the transmission bit rate to be assigned to the bearer-line in accordance with the information output from the pseudo-speech signal control information extracting section 31 . In this case, since the information output from the pseudo-speech signal control information extracting section 31 indicates that the coded speech signal included in the pseudo-speech signal of the trunk channel is 8 kbits/s, the assignment controller 4 assigns the 8 kbits/s to the bearer line. In addition, it controls such that the coded speech signal output from the transmission bit rate restorer 19 is selected and output. [0216] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s coded speech signal. [0217] The DCME 103 decodes the 8-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0218] When the number of the trunk channels in the speech active state exceeds the threshold value, the assignment controller 4 always assigns the trunk channel to the bearer line for the DCME 103 at the bit rate of 8 kbits/s without considering the information output from the pseudo-speech signal control information extracting section 31 , and controls such that the coded speech signal output from the transmission bit rate restorer 19 is selected and output. [0219] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s coded speech signal. [0220] The DCME 103 decodes the 8-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0221] In contrast, when the DCME 100 transmits a 6.4-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 6.4-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0222] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, has the assignment controller 4 decide the transmission bit rate to be assigned to the bearer line in accordance with the supervisory result of the speech activity channel number supervisor 40 . [0223] When the number of the trunk channels in the speech active state is equal to or less than the threshold value, the assignment controller 4 decides the transmission bit rate to be assigned to the bearer line in accordance with the information output from the pseudo-speech signal control information extracting section 31 . In this case, since the information output from the pseudo-speech signal control information extracting section 31 indicates that the coded speech signal included in the pseudo-speech signal of the trunk channel is 6.4 kbits/s, the assignment controller 4 assigns the 6.4 kbits/s to the bearer line. In addition, it controls such that the coded speech signal output from the transmission bit rate restorer 19 is selected and output. [0224] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 6.4 kbits/s, so that it transmits the 6.4-kbit/s coded speech signal. [0225] The DCME 103 decodes the 6.4-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0226] When the number of the trunk channels in the speech active state exceeds the threshold value, the assignment controller 4 always assigns the trunk channel to the bearer line for the DCME 103 at the bit rate of 8 kbits/s without considering the information output from the pseudo-speech signal control information extracting section 31 , and controls such that the coded speech signal output from the coding bit rate information adding section 30 is selected and output. [0227] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s signal including the 6.4-kbit/s coded speech signal plus the coding bit rate information. [0228] The DCME 103 recognizes the 6.4-kbit/s coded speech signal from the coding bit rate information added to the 8-kbit/s signal, decodes it into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0229] Thus controlling the bit rate assigned to the bearer line in the second link in accordance with the number of the trunk channels in the speech activity state, the present embodiment 6 can implement high quality and low bit rate transmission without degrading the speech quality in the variable bit rate DCME with the tandem passthrough function. [0230] Embodiment 7 [0231] [0231]FIG. 8 is a block diagram showing a configuration of an embodiment 7 of the digital circuit multiplication equipment in accordance with the present invention. In FIG. 7, the same reference numerals designate the same or like portions to those of FIG. 1, and hence the description thereof is omitted here. [0232] In FIG. 8, the reference numeral 41 designates a bearer occupancy rate supervisor for monitoring the bearer occupancy rate of the bearer line (the rate of the capacity of busy bearer channels to the capacity of the bearer line). Next, the operation of the present embodiment 7 will be described. [0233] For example, the operation of the variable bit rate DCMEs with transmission bit rates of 8 kbits/s and 6.4 kbits/s will be described. [0234] The bearer occupancy rate supervisor 41 monitors the rate of the capacity of the bearer channels that are occupied on the bearer line to the capacity of the bearer line. When the bearer occupancy rate is small, the load on the DCME is light, and hence the assignment to the bearer line, which is requested by the speech coding bit rate information and speech activity/silence information sent from the first link, can be carried out without detaining the request. On the other hand, when the bearer occupancy rate is large, the load on the DCME is heavy, and hence the request is not always carried out soon. [0235] In view of this, the bearer occupancy rate supervisor 41 has a particular threshold value, and when the bearer occupancy rate exceeds the threshold value, it supplies the assignment controller 4 with a command to assign the passthrough state trunk channel to the bearer line at 8 kbits/s in the second link as in the foregoing embodiment 1. In contrast, when the bearer occupancy rate is equal to or less than the threshold value, it provides the assignment controller 4 with a command to assign the bit rate of 8 kbits/s or 6.4 kbits/s to the bearer line in accordance with the request from the first link. [0236] The operation of the foregoing DCMEs will now be described on the path from the telephone 110 to the telephone 111 as shown in FIG. 12. [0237] When the DCME 100 transmits an 8-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 8-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0238] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, has the assignment controller 4 decide the transmission bit rate to be assigned to the bearer line in accordance with the supervisory result of the bearer occupancy rate supervisor 41 . [0239] When the bearer occupancy rate is equal to or less than the threshold value, the assignment controller 4 decides the transmission bit rate to be assigned to the bearer line in accordance with the information output from the pseudo-speech signal control information extracting section 31 . In this case, since the information output from the pseudo-speech signal control information extracting section 31 indicates that the coded speech signal included in the pseudo-speech signal of the trunk channel is 8 kbits/s, the assignment controller 4 assigns the 8 kbits/s to the bearer line. In addition, it controls such that the coded speech signal output from the transmission bit rate restorer 19 is selected and output. [0240] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s coded speech signal. [0241] The DCME 103 decodes the 8-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0242] When the bearer occupancy rate exceeds the threshold value, the assignment controller 4 always assigns the trunk channel to the bearer line for the DCME 103 at the bit rate of 8 kbits/s without considering the information output from the pseudo-speech signal control information extracting section 31 , and controls such that the coded speech signal output from the transmission bit rate restorer 19 is selected and output. [0243] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s coded speech signal. [0244] The DCME 103 decodes the 8-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0245] In contrast, when the DCME 100 transmits a 6.4-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 6.4-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0246] Receiving the 64-kbit/s pseudo-speech signal from the circuit switch 106 , the DCME 102 , which knows that the trunk channel is in the passthrough state, has the assignment controller 4 decide the transmission bit rate to be assigned to the bearer line in accordance with the supervisory result of the bearer occupancy rate supervisor 41 . [0247] When the bearer occupancy rate is equal to or less than the threshold value, the assignment controller 4 decides the transmission bit rate to be assigned to the bearer line in accordance with the information output from the pseudo-speech signal control information extracting section 31 . In this case, since the information output from the pseudo-speech signal control information extracting section 31 indicates that the coded speech signal included in the pseudo-speech signal of the trunk channel is 6.4 kbits/s, the assignment controller 4 assigns the 6.4 kbits/s to the bearer line. In addition, it controls such that the coded speech signal output from the transmission bit rate restorer 19 is selected and output. [0248] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 6.4 kbits/s, so that it transmits the 6.4-kbit/s coded speech signal. [0249] The DCME 103 decodes the 6.4-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0250] When the bearer occupancy rate exceeds the threshold value, the assignment controller 4 always assigns the trunk channel to the bearer line for the DCME 103 at the bit rate of 8 kbits/s without considering the information output from the pseudo-speech signal control information extracting section 31 , and controls such that the coded speech signal output from the coding bit rate information adding section 30 is selected and output. [0251] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s signal including the 6.4-kbit/s coded speech signal plus the coding bit rate information. [0252] The DCME 103 recognizes the 6.4-kbit/s coded speech signal from the coding bit rate information added to the 8-kbit/s signal, decodes it into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0253] Thus controlling the bit rate assigned to the bearer line in the second link in accordance with the bearer occupancy rate, the present embodiment 7 can implement high quality and low bit rate transmission without degrading the speech quality in the variable bit rate DCME with the tandem passthrough function. [0254] Embodiment 8 [0255] [0255]FIG. 9 is a block diagram showing a configuration of an embodiment 8 of the digital circuit multiplication equipment in accordance with the present invention. In FIG. 8, the same reference numerals designate the same or like portions to those of FIG. 1, and hence the description thereof is omitted here. [0256] In FIG. 9, the reference numeral 42 designates a coding bit rate converter (information reduction means) for generating a low coding bit rate coded speech signal by removing the information amount of a quantization table and the like from the data sequence of the coded speech signal; and 43 designates a selector (speech signal output means) for selecting and outputting one of the outputs of the transmission bit rate restorer 19 , coding bit rate converter 42 and coding bit rate information adding section 30 in accordance with a command from the assignment controller 4 . [0257] Next, the operation of the present embodiment 8 will be described. [0258] For example, the operation of the variable bit rate DCMEs with transmission bit rates of 8 kbits/s and 6.4 kbits/s will be described. [0259] The coding bit rate converter 42 generates the low coding bit rate coded speech signal from the data sequence of the coded speech signal by deleting the information such as the quantization table. [0260] When the coded speech signal recovered by the transmission bit rate restorer 19 is 8 kbits/s, the pseudo-speech signal control information extracting section 31 notifies the assignment controller 4 of the fact so that the assignment controller 4 assigns the 8-kbit/s transmission bit rate to the bearer line. In accordance with the command from the assignment controller 4 , the selector 43 selects and outputs the coded speech signal supplied from the transmission bit rate restorer 19 . [0261] In contrast, when the assignment controller 4 assigns the 6.4-kbit/s transmission bit rate to the bearer line, the selector 43 selects and outputs the coded speech signal output from the coding bit rate converter 42 in accordance with the command from the assignment controller 4 . [0262] When the coded speech signal recovered by the transmission bit rate restorer 19 is 6.4 kbits/s, and the pseudo-speech signal control information extracting section 31 notifies the assignment controller 4 of the fact, but the assignment controller 4 assigns the 8-kbit/s transmission bit rate to the bearer line, the selector 43 selects and outputs the coded speech signal supplied from the coding bit rate information adding section 30 in accordance with the command from the assignment controller 4 . [0263] On the other hand, when the assignment controller 4 assigns the 6.4-kbit/s transmission bit rate to the bearer line, the selector 43 selects and outputs the coded speech signal output from the transmission bit rate restorer 19 in accordance with the command from the assignment controller 4 . [0264] The operation of the foregoing DCMEs will now be described on the path from the telephone 110 to the telephone 111 as shown in FIG. 12. [0265] When the DCME 100 transmits an 8-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 8-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0266] In the DCME 102 , the assignment controller 4 decides the transmission bit rate to be assigned to the bearer line in accordance with the load condition on the DCME, for the trunk channel in the passthrough state in the same manner as for the trunk cha el in the non-passthrough state. [0267] When the assignment controller 4 assigns 8 kbits/s to the bearer line for the trunk channel, it provides the selector 43 with a command to select and output the coded speech signal output from the transmission bit rate restorer 19 . [0268] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s coded speech signal. [0269] The DCME 103 decodes the 8-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0270] On the other hand, when the assignment controller 4 assigns 6.4 kbits/s to the bearer line for the trunk channel, it provides the selector 43 with a command to select and output the coded speech signal output from the coding bit rate converter 42 . [0271] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 6.4 kbits/s, so that it transmits the 6.4-kbit/s coded speech signal obtained by reducing the information amount from the 8-kbit/s coded speech signal. [0272] The DCME 103 decodes the 6.4-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0273] In contrast, when the DCME 100 transmits a 6.4-kbit/s coded speech signal to the DCME 101 , the DCME 101 adds the dummy data including the pseudo-speech signal control information to the 6.4-kbit/s coded speech signal, and sends the 64-kbit/s pseudo-speech signal to the circuit switch 106 . [0274] In the DCME 102 , the assignment controller 4 decides the transmission bit rate to be assigned to the bearer line in accordance with the load condition on the DCME, for the trunk channel in the passthrough state in the same manner as for the trunk channel in the non-passthrough state. [0275] When the assignment controller 4 assigns 8 kbits/s to the bearer line for the trunk channel, it provides the selector 43 with a command to select and output the coded speech signal output from the coding bit rate information adding section 30 . [0276] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 8 kbits/s, so that it transmits the 8-kbit/s signal including the 6.4-kbit/s coded speech signal plus the coding bit rate information. [0277] The DCME 103 recognizes the 6.4-kbit/s coded speech signal from the coding bit rate information added to the 8-kbit/s signal, decodes it into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0278] On the other hand, when the assignment controller 4 assigns 6.4 kbits/s to the bearer line for the trunk channel, it provides the selector 43 with a command to select and output the coded speech signal output from the transmission bit rate restorer 19 . [0279] As a result, the bearer line for the DCME 103 is assigned the transmission bit rate of 6.4 kbits/s, so that it transmits the 6.4-kbit/s signal. [0280] The DCME 103 decodes the 6.4-kbit/s coded speech signal into a 64-kbit/s PCM signal, and supplies the PCM signal to the telephone 111 via the circuit switch 105 . [0281] Thus controlling the coding bit rate of the coded speech signal to be assigned to the bearer line in accordance with the relationship between the coding bit rate of the coded speech signal from the first link and the assignment to the bearer line in the second link, the present embodiment 8 can implement high quality and low bit rate transmission without degrading the speech quality in the variable bit rate DCME with the tandem passthrough function. [0282] Incidentally, the speech multiplication equipment as shown in FIGS. 1 - 3 and 5 - 9 can be implemented by a digital signal processor in conjunction with programs carrying out the functions described above.

Digital circuit multiplication equipment (DCME) refers to coding bit rate information included in a pseudo-speech signal. In accordance with the coding bit rate information, the DCME selects either a coded speech signal extracted by a transmission bit rate restorer or a coded speech signal including bit rate identification information added by a coding bit rate information adding section, and supplies the selected coded speech signal to a bearer line. The DCME can solve a problem of a conventional DCME in that a mismatch can take place between the actual transmission bit rate of the coded speech signal and the transmission bit rate assigned to the bearer line when providing the variable bit rate DCME with a tandem passthrough function, and therefore the correct coding bit rate information cannot be transferred to a speech decoder, bringing about serious degradation in the speech quality.

CROSS REFERENCES TO RELATED APPLICATIONS This application is a division of Ser. No. 14,005 filed Feb. 21, 1979 now abandoned which was a continuation of Ser. No. 851,651 filed Nov. 15, 1977 now abandoned, which was a continuation-in-part of Ser. No. 673,567 filed Apr. 5, 1976 now abandoned. BACKGROUND OF THE INVENTION 1. Field of the Invention In one aspect, this invention relates to vacuum distillation systems. In another aspect, this invention relates to closed loop waste treating systems. In yet a further aspect, this invention relates to methods of using distillation systems. 2. Description of the Prior Art Prior art distillation systems wherein a variable speed compressor is used to put energy into a vapor which is in turn condensed to give off latent heat of vaporization to a distilland are known in the art. One example of such a system is shown by U.S. Pat. No. 2,446,880. These systems have been primarily used for water desalinization and operate at temperatures near or even above the boiling point of water at atmospheric pressure. Such systems are not desirable for distilling fruit juices or plating solutions; since they must be concentrated at temperatures well below the boiling point of water to prevent degradation of the organic materials present. SUMMARY OF THE INVENTION It is an object of this invention to provide an improved method of controlling the vapor compression process. The vapor compression system of this invention has an evaporation chamber maintained at a reduced pressure, a concentration chamber for holding the distilland to be concentrated, a density measuring means for measuring distilland density, and an evaporation surface connecting to the concentration and evaporation chambers. This configuration allows the distilland to be retained within the concentration chamber until the desired distilland concentration measured as a function of density is obtained. As a further feature of this invention, the compressor capacity is increased until the compressor reaches a surge condition and the compressor capacity is reduced an incremental amount to bring the compressor into the desired operating range. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawing: FIG. 1 is a schematic drawing of a plating line which includes a vapor compression unit of this invention and is adapted for closed loop operation; FIG. 2 is a side elevation view in partial section of a vapor compression unit incorporating features of this invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A typical plating schematic using a vapor compression still is shown in FIG. 1. Parts to be plated are placed in a plating tank 12 which contains a solution of ions to be deposited on the parts as a metal layer. After a metal layer has been deposited on the parts, the plated parts are moved successively to rinse tanks 14, 16, 18 where any plating solution clinging to the plated part is rinsed off. A substantial amount of plating solution, containing valuable metal ions and organic additives, is carried into the rinse tanks. Also, some water is carried from tank to tank by the parts as they are rinsed. The carry over and evaporation from the rinse tanks depletes the water in the rinse tanks and the concentration of plating solution will steadily rise, especially in the first rinse tank 14. A portion of the water in the first rinse tank 14 is periodically withdrawn from the bottom of the tank and sufficient water from the second tank 16 is transferred via line 15 to refill tank 14. The tank 16 is refilled from tank 18 via line 17 and tank 18 is in turn filled by purified water from a vapor compression still 20 via line 19. Additional water can be added from an outside source of fresh water 21 when needed. As shown, the rinse water or distilland from the first rinse tank 14, is withdrawn at outlet 22 by opening valve 24. The contaminated rinse water is conveyed by a pipe 26 to a heat exchanger 28 where the rinse water extracts some heat from purified water condensed in the vapor compression still 20. The preheated rinse water passes through a three-way valve 30 and is fed to the vapor compression still from the rinse water. The rinse water is concentrated to a density suitable for return to the plating tank 12. The concentrated solution is withdrawn from the concentration chamber through a valve 32 and pumped to the plating tank 12 via a line 34. The pure water resulting from the vapor compression cycle is withdrawn through valve 36 into the heat exchanger 28 via line 38 and then is returned to rinse tank 18 by line 19. If desired, the vapor compression system can be used to purify water before it enters the plating cycle. Treatment of the water before it enters the system removes the calcium, magnesium, and other undesired metal ions which are present in every source of water. These metal ions will concentrate in the plating bath as water is lost and settle out as solid salts to form a sludge at the bottom of the tank 12 or remain in the plating solution. In either case, the increasing concentration of undesired metal ions reduces plating efficiency. Eventually the plating solution must be discarded, resulting in a loss of valuable metal ions in the solution discarded, or the sludge must be removed from the plating tank requiring that plating operations be suspended. Accumulation of this sludge would be particularly pronounced where the process cycle is a closed loop as shown. Purification of the incoming fresh water would lessen or eliminate this problem. FIG. 2 shows a detailed view of one vapor compression apparatus useful in the practice of this invention. The operation of this unit is described with reference to plating rinse water. The system could also be used to treat other liquids such as fruit juices, organic solvents or sea water. A generally cylindrical, vertically oriented housing 39 defines an evaporation chamber 40 which collects vaporized water from the inside of the tubes 54 located at one end of the housing near a compressor 42. The compressor 42 comprises generally a compressor wheel 43, volute 45 and driving means 46. As shown, the driving means is an electric motor 47 mounted on a bracket 48 attached to the housing 39. The motor 47 drives a V-belt drive 49 which in turn rotates the compressor wheel 43. The compressor wheel 43 withdraws vapor from the evaporation chamber maintaining the evaporation chamber at a reduced pressure e.g., 0.5 to 1.5 pisa. As shown, cross-tubes 50 transport compressed vapor from the volute 45 to a condensation-heat exchanger chamber 52. At the lower end of the housing 39, distal the compressor 42, are a number of concentration chambers (three being shown) 44a, 44b, 44c which are filled with rinse water to be concentrated or incoming fresh water to be purified. Each concentration chamber is fluidly connected to the evaporation chamber 40 by an evaporation surface. As shown, the fluid connection is by means of capillary tubes 54 which extend from the lower portion of their respective concentration chambers and terminate in the plate 56 which forms the floor of the evaporation chamber 40. In general there will be a plurality of tubes extending from each concentration chamber into the evaporation chamber, only one tube per concentration chamber being shown for clarity. The interior walls of the capillary tubes 54 are wet by the liquid being concentrated and provide a large surface area for the formation of water vapor which passes into the evaporation chamber 40. Sensing means 58a, 58b, and 58c are installed in each concentration chamber to measure the concentration of the remaining liquid. As shown, the various sensing means generate an electrical signal which is fed to a control means 60. The control means 60 activates the three-way valve 32 so that the concentration chambers can be emptied when the liquid in the chambers reaches the desired concentration. In one aspect of this invention the concentration of the remaining liquid is determined by measuring its density. Suitable density measuring devices are known in the liquid measuring art. One general method of density measurement, which could be used in practicing this invention, is displacement measurement using a float. Such devices operate by submerging a float in the liquid to be measured. The float's movement up and down within the liquid generates a continuously variable signal proportional to the density of the surrounding liquid. A full description can be found in Chemical Engineers Handbook, 5th Ed., McGraw-Hill, New York, 1973, especially pages 22-48, and 49, the disclosure of which is incorporated herein by reference. In general, pumps (not shown) would be associated with the various valves to move the liquid within the system as needed. The chamber would be replenished via valve 30 with more liquid to be concentrated as needed. A large diameter vertically oriented duct 51 extends longitudinally along the middle of housing 39. Overflow liquid from tubes 54 flows into the duct and down into a reservoir 65. The liquid in reservoir 65 can in turn be pumped by a pump 66 through a valve 68 to the inlet of valve 30, returning the overflow liquid into the concentration chamber. OPERATION In general, as with stills of this type, vapor from the liquid being treated will be generated on an evaporation surface. The vapor generated will be drawn into a compressor, compressed, and the compressed vapor is condensed. Generally the vapor is condensed so that the latent heat of condensation is transferred to the liquid being treated thereby creating more vapor to be compressed. In greater detail, vapor exiting from the upper end of tubes 54 will enter the evaporation chamber 40, passing over the cross tubes 50. As the vapor passes the cross tubes 50, it will remove some heat from the cross tubes which super heats the vapor and lowers the heat in the compressed vapor. The rising vapor enters a liquid carrier 74 which will remove any remaining liquid droplets entrained in the vapor stream. The barrier is shown as a screen but can be other materials known in the art, one barrier material being porous agglomerated plate. The vapor, free from liquid, enters the housing surrounding the rotating compressor wheel 43, is accelerated by the wheel and is pushed into the volute 45 where the vapor's velocity decreases and the pressure increases. The vapor from volute 45 enters the cross tubes 50 and passes through the tubes to a plenum 76 located within the housing. From the plenum, the compressed vapor enters a variable capacity heat exchange chamber. The heat exchange chamber comprises the chamber 52 defined by the plate 56, the upper surface of concentration chamber 44a, and the housing 39. Vapor entering the chamber 52 will be exposed to the exterior walls of the tubes 54 and, being at a higher temperature and pressure than the liquid inside the tubes, will condense to form a liquid. As shown, the chamber 52 contains a quantity of liquid and a vapor filled space 66 above the liquid. The heat transfer to the capillary tubes is different for the vapor filled phase and the liquid phase. By varying the liquid level within the heat exchange chamber 52, the amount of heat transferred to the liquid within the tubes 36 and thus the amount of additional vapor created can be controlled. The heat transfer and thereby the amount of vapor can also be controlled by varying the height of solvent within the tubes, a lower liquid level resulting in a lower heat transfer. Of course, control of the vapor compression still involves several variables in addition to the liquid level in the chamber 52 or tubes 54. With a given compressor wheel, the amount of liquid withdrawn from the concentration chambers will vary as a function of: compressor wheel speed, inlet geometry and guide vane angle. In general, if the liquid level in the heat exchange chamber is increased, the amount of heat available to evaporate solvent and concentrate liquid is decreased. The inlet geometry can be changed to vary the compressor's operating capacity. Such variable inlet geometries are well known in the art and a further description is omitted in the interest of brevity. Because of changes in the distilland or variations in the production process to which this system is attached changes are necessary from time to time. One method of operating the compressor of this system is to increase the compressor capacity, such as by increasing compressor wheel speed until the compressor crosses the surge line and begins to surge. The compressor capacity could then be reduced by a fixed amount, such as by changing compressor speed or inlet geometry, to bring the capacity to the desired point on the efficiency curve. The operating efficiency curves are determined by the variables present in the system each system being individualistic but the operating characteristic curve as easily calculated or emperically determined. Such charts showing efficiency islands as a function of pressure ratio versus flow at a constant impeller tip speed are so well known that a detailed example is omitted. One example of a centrifugal compressor performance chart can be found in Gas Turbines, Sorenson, Ronald Press Co., New York, 1951, especially page 267. Ordinarily causing a centrifugal compressor wheel to surge would not be a viable means of controlling a process. However, because the compressor wheel is operating at a reduced pressure, the amount of energy applied to the wheel during surge is minimal. Using the surge point of the compressor as a control measurement provides a quick and easy method of determining the operating conditions at a given time since the pressure ratio changes markedly when the compressor surges. Pressure sensing devices are well known in the art and a detailed description is omitted in the interest of brevity. The surge control can be used in combination with the variable heat exchanger to further increase the efficient operating range of the system. The operating steps detailed above could be performed by a microprocessor which would receive relevant data and determine the operating condition of the system by comparison with a predetermined performance chart. If the system needed correction, the microprocessor would be programmed to drive the system into the surge condition and adjust the compressor capacity as discussed hereinbefore. Where the liquid in one of the concentration chambers 44a, 44b, and 44c reaches the desired concentration, the sensing means in the associated chamber will activate the control means 60 which in turn activates the valve 32 to empty the concentration chambers. The emptied chamber is refilled and the process continues. Various modifications and alterations of this invention will become obvious to those skilled in the art without departing from the scope and spirit of this invention. For example, the still of this invention can be used to concentrate fruit juice and for disalinization of water in addition to treating plating rinse water.

A liquid containing a solvent to be evaporated is fed to a concentration chamber which is fluidly connected to an evaporation chamber maintained at a reduced pressure. A vapor compression means withdraws solvent vapor from the evaporation chamber, compresses the vapor and forces the compressed vapor to a liquification chamber. Regulator means responsive to the density of the liquid remaining within the concentration chamber will regulate the rate of solvent evaporation to provide a concentrate suitable for recycling. A method of operating the still of this invention utilizes the technique of increasing the compressor capacity until the compressor begins to surge and then reducing the capacity a fixed amount to provide the desired efficiency.

BACKGROUND OF THE INVENTION The present invention relates to tires for heavy vehicles, such as trucks and buses. More particularly, it relates to the beads of radial carcass tires which have at least one bead wire in each bead and are intended to be mounted on rims defined in accordance with the existing standards and having flanges axially on the outside. In certain cases, tires for heavy vehicles are called upon to support substantial overloads which produce flexings at the level of the side walls of the tire of an amplitude which is greater, and therefore more disadvantageous, the greater the overload. This problem is also encountered in the case of twin tires when one of the two tires has suffered a loss of pressure, as the result, for instance, of a puncture, and the other tire, which bears the entire load, experiences at its sidewalls flexings which are very disadvantageous for the life of the carcass reinforcement. Finally, for certain heavy vehicles there is a demand for tires the overall diameter of which is substantially reduced while they retain the profiles and dimensions of rims at present on the market in order to increase the useful load transported; if H represents the height of the tire mounted on its rim, measured on a meridian section between the point of the bead closest to the axis of rotation and the outermost point of the tread of the tire and S the overall width of the tire measured parallel to the axis of rotation, the aspect ratio is defined by H/S. In the case of aspect ratios less than or equal to 0.6, poor resistance to fatigue of the tire under the cycles imposed by travel is noted; in each side wall of the tire extending between a bead and the belt of the crown, the corresponding portion of the radial carcass is reduced in height and, therefore, each carcass cord undergoes cycles of flexure along small radii of curvature. In operation, upon each revolution of the wheel these cords are subjected to cycles of variation in curvature which are more disadvantageous the smaller this aspect ratio and therefore these radii of curvature. Various proposals are known which are directed at overcoming excessive fatigue in the sidewall of a tire during the course of travel. Among them, mention may be made of French Patent No. 1,502,689 which discloses that by reinforcing this zone of the tire with, for instance, a layer of rubber stock, the tire is imparted additional rigidity and it is thus possible to decrease the amplitude of the flexing cycles. However, such an arrangement results in an increase in weight and particularly in heating of the sidewalls and therefore in a consumption of energy. Another proposal disclosed in French Patent Application No. 2,415,016 suggests producing a "depression" in the sidewall of the tire, thus making it possible to reduce the height of the bead and increase the height of the sidewall and therefore to increase the flexibility of the sidewall. This solution makes it possible effectively to increase the life of the sidewalls under strong flexure, but in a manner which is still limited in part due to the fact that the zone of the bead of the tire which is furthest radially to the outside is still forced to flex along the profile of the flange of the rim. While these two proposals make it possible substantially to increase the life of the sidewall, they still are insufficient in the case of tires of ratios less than or equal to 0.6. SUMMARY OF THE INVENTION The object of the present invention is to produce a radial carcass tire mounted on a rim having bead seats which are extended radially and axially to the outside by flanges and the sidewalls of which tire have in inflated state radii of curvature which are substantially greater than those obtained on a tire of the same dimensions made in accordance with the prior art. Another object is in this way to obtain longer life under the loading cycles caused by travel and under static or dynamic overloads. The object of the present invention described with reference to the accompanying drawings is a tire for heavy vehicles which is intended to be mounted on a rim J having two bead seats which are extended axially and radially towards the outside by flanges of radius R J , each bead B comprising at least one bead wire 2 of inner radius R T around which a radial carcass armature is anchored by turning-up, characterized by the fact that (a) the center of gravity 21 of the meridian section of the bead wire 2 is located radially to the outside of the rim flange, (b) the bead wire 2 has a modulus of elasticity at least equal to 100,000 MPa and its clamping on the rim flange s=(R J -R B )/(R T -R B ) is between 0.1 and 0.9, R B being the radius of the bead of the unmounted tire measured in the plane perpendicular to the axis of rotation and passing through the center of gravity 21 of the cross section of the bead wire 2. By located radially to the outside of the rim flange, it is to be understood that the center of gravity 21 is located at a distance from the axis of rotation greater than R J and is positioned on a straight line perpendicular to the axis of rotation passing between the point K, the point of connection between the generatrix of the seat of the rim and the flange of the rim, and the point L, point of the furthest axially outward point of the flange of the rim. In the present invention, in the case of the tire mounted on its rim and inflated to its operating pressure and subjected to its average load of use, the axial component of the forces exerted by the bead on the rim flange resulting from the effects of the inflation pressure and the lateral stresses imposed on the tire along a curve is balanced, for instance, by frictional forces and wedging forces developed between the bead and the rim flange. Adaptation of these forces can be effected by adjusting the value of the clamping of the bead wire 2 and the position of its center of gravity 21 radially to the outside of the rim flange and axially with respect to this same rim flange. In this position of the bead wire spaced both radially to the outside and axially to the outside with respect to its traditional position, the radius of curvature of the radial reinforcements of the carcass ply is increased, which improves the resistance to fatigue of said reinforcements. This effect on the radius of curvature of the sidewalls can be further improved if the turn-up of the carcass ply around the bead wire 2 is effected radially towards the inside of the tire. One advantage of the present invention is the possibility of retaining the rims at present available and in particular of retaining the same diameters of the brake-drum on which the assembly consisting of tire and rim is mounted. The present invention permits a possible decrease in the outside diameter of the tire in order to obtain a tire having an aspect ratio which is less than or equal to 0.6 with a small section height H while having sidewalls the radii of curvature of which are sufficiently great and assuring a suitable locking of the beads on the rim. In order to improve, in time, the holding of the tire on the rim with due consideration of the phenomena of flow of the rubber mixes located radially below the bead wire 2, it is advantageous for the portion of the bead B axially to the inside with respect to the bead wire 2 to be extended radially towards the inside by means of an extension 5; said extension may even come into contact with the seat of the rim. In order to maintain, over the course of time, a force of contact between the portion 5 of the bead B and the rim seat, this extension may be reinforced by various materials, such as, for instance, textile or metal cords arranged annularly or at least a bead wire of any cross section. In order to assure an effective holding of the bead on the rim even under the effect of thermal stresses generated by the heating of the brake drums as a result of repeated braking, it may be advantageous, while reinforcing the portion 5 of the bead B axially and radially to the inside with respect to the bead wire 2 with, for instance, a bead wire 3 of a modulus of at least 4000 MPa, to arrange one or more connecting plies between the bead wire 3 and the portion of the bead radially to the outside of the flange of the rim. The role of this ply is to avoid any danger of axial displacement towards the outside of the portion of the bead radially to the outside of the rim flange under the effect of thermal and mechanical stresses. The cords or cables of each connecting ply are directed in such a manner as to form an angle of between -45° and +45° with respect to the orientation of the carcass reinforcement. The description which follows, read with reference to the accompanying drawing which shows possible embodiments and is given solely by way of example, will permit of a better understanding of the invention. DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a view of the transverse half-section of a tire mounted on its rim in accordance with the invention, the axis XX' being the axis of symmetry of the figure; FIG. 2 is a meridian view of a tire bead, not mounted on a rim, in accordance with the invention; FIG. 3 is a variant embodiment of the invention in which the portion of the bead furthest axially and radially to the inside comprises a reinforcement bead wire around which there is wound a connecting ply the ends of which are located on opposite sides of the bead wire which is located radially to the outside of the rim flange; and FIG. 4 is another variant embodiment of the invention in which the two ends of a connecting ply are arranged on the same side with respect to the bead wire which is located radially to the outside of the flange of the rim. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 shows, in solid lines, the meridian half section of a tire of size 295/50 R 22.5 developed in accordance with the invention, and superimposed on that, drawn in dashed lines, a tire of the same size in accordance with the prior art, these two tires being mounted on the same rim. In this example, the mounting rim J comprises two bead seats, the generatrices of which form an angle of 15°±1° with a line parallel to the axis of rotation, said seats being extended radially and axially towards the outside by flanges in the form of a circular arc of radius 12.7 mm; for said mounting rim the radius R J corresponds to the radial distance between the axis of rotation and a point A of the flange furthest away from the axis of rotation. The point K is the point of connection between the rim seat and the rim flange and the point L is the point of the rim flange furthest axially to the outside. The tire developed in accordance with the invention comprises a bead wire of "braided" type of interior radius R T , the center of gravity 21 of the section of which is located radially with respect to the axis of rotation at a distance greater than the radius R J of the rim flange and is positioned axially on a straight line perpendicular to the axis of rotation passing between the point K and the point A of the rim flange furthest radially to the outside. A carcass reinforcement 1 of metal cables formed of 12 wires of 18/100 is turned up axially towards the inside around the bead wire 2 to form the turn-up 1', this making it possible to avoid the presence of a point of inflection of the carcass reinforcement above the bead wire 2 and thus to increase the height of the sidewall and therefore the radius of curvature of the sidewall of the inflated tire. The bead wire 2 of "braided" type has a modulus of elasticity extension equal to 150,000 MPa and its clamping s=(R J -R B )/(R T -R B ) is equal to 0.3 in order to assure the locking of the bead on the rim flange, R B (see FIG. 2) being the radius of the bead of the tire not mounted on the rim measured in the plane which is perpendicular to the axis of rotation and passes through the center of gravity of the cross section of the bead wire 2. It will be noted that, while having a tire the aspect ratio H/S of which is in this case equal to 0.5, it has been able to retain for the sidewall of the 295/50 R 22.5 tire an average radius of curvature R 2 of the carcass reinforcement which is greater than the average radius R 1 measured on the sidewall of the tire constructed with a bead in accordance with the prior art. FIG. 2 shows the bead B of a tire developed in accordance with the invention, not mounted on a rim; this bead comprises a carcass ply 1 which is turned up axially towards the inside around a bead wire of "braided" type, positioned in the bead B in such a manner that, once the tire is mounted on the rim, the center of gravity 21 of the cross section of the bead wire 2 is located radially to the outside of the flange of the rim and axially between the two straight lines perpendicular to the axis of rotation and passing through the points K and A. The said bead also comprises a portion 5 of rubber mix which is axially towards the inside with respect to the bead wire 2 and which extends the bead B radially towards the axis of rotation in contact with a portion of the rim flange. FIG. 3 shows a variant of the invention in which the bead B is extended radially towards the axis of rotation by a portion 5 axially and radially to the inside with respect to the bead wire 2 which is itself positioned radially to the outside of the flange of the rim J; the said portion 5 comes into contact with the seat of the rim J and is reinforced by a bead wire 3 of "braided" type of a modulus equal to 100,000 MPa. Around this bead wire 3 there is wound a connecting ply formed of textile cords, the turn-ups 4 and 4' of which cover, on the two sides, the carcass reinforcement 1 and its turn-up 1'. The end of the turn-up 4' is located at a distance from the axis of rotation greater than the inner radius R T of the bead wire 2 and less than the radius R E of the end of the turn-up 1' of the carcass reinforcement; the end of the turn-up 4 is located at a distance from the axis of rotation greater than the radius of the end of the turn-up 1' of the carcass reinforcement. The cords of this connecting ply are disposed radially. FIG. 4 shows another tire bead developed in accordance with the invention and mounted on a rim in which the portion 5 of the bead B axially and radially to the inside with respect to the bead wire 2 is extended until coming into contact with the seat of the rim J and comprises a bead wire 3 of "braided" type of a modulus equal to 100,000 MPa, around which there is wound a connecting ply of radially arranged textile cords, the turn-ups 4 and 4' of which are in part superimposed and are both located on the side axially to the outside of the carcass reinforcement. The ends of the turn-ups of the connecting ply are located, with respect to the axis of rotation, at distances greater than the inside radius R T of the bead wire 2 and less than the radius R E of the end of the turn-up 1' of the carcass reinforcement. In order to avoid a discontinuity in resistance to flexure of the zone of the bead located radially to the outside of the bead wire 2, the ends of the turn-ups of the connecting ply are staggered with a minimum stagger of 10 mm between their respective radii. It should be noted that in the variant tire bead structures shown in FIGS. 3 and 4, the development of the clamping on the flange as a function of time is better controlled due to the fact that a part of the rubber stocks is replaced by at least one ply of a non-flowing material.

A tire structure with radial carcass reinforcement for heavy vehicles and rticularly a tire bead structure which makes it possible to have, on unmodified rims, sidewalls the radii of curvature of which are sufficiently great to avoid premature fatigue of the constituent reinforcement elements of the carcass as a result of the flexing cycles generated by travel. The said tire structure has at least one bead wire (2) which is located radially to the outside of the rim flange (J) and around which the turn-up (1') of the carcass (1) is formed.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of UK Patent Application No. 1504057.9, filed 10 Mar. 2015, the entire contents and substance of which is hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to an exercise equipment storage apparatus, and in particular a reconfigurable shelving unit for weighted exercise equipment. [0004] 2. Description of Related Art [0005] An ever increasing range of exercise equipment is available to gym owners for use by gym users in fitness and strength training. A wider range of exercise equipment enables a gym to provide a wider range of training facilities and to cater for a greater range of customers. Exercise equipment in a gym environment must be stored in an accessible manner such that it is freely yet safely accessible to the gym users. Given the finite space within a gym facility and the requirement to maintain as much free floor space as possible, the amount of exercise equipment a gym may provide is limited by the floor space available and efficiency with which the storage apparatus holds the equipment. [0006] Given the diversity in the shape and size of modern exercise equipment, storage is typically individually tailored to specific equipment, with dedicated storage being required for each range of equipment. Typically storage is in the form of shelving racks. In order to maintain equipment safely in position on the shelves a retaining element is required to hold, cradle or otherwise restrain the equipment, which differ in size and orientation from equipment to equipment. It is therefore not generally possible to safely store more than one type of equipment on a given storage apparatus. As a result, the requirement to provide a wide range of different storage solutions results in storage inefficiency and limits the variety of equipment that may be provided. [0007] In addition, should a gym owner decide to replace a range of equipment with an alternative, they must purchase a new rack to hold the alternative range of equipment, adding significantly to the cost of updating their equipment. A further disadvantage, particularly for smaller gyms that require equipment in more limited numbers, is that the number of units of each type of equipment may be significantly less than the number of units which the dedicated storage unit is configured to store. Therefore, the storage unit represents an inefficient use of space and Cost. [0008] It is therefore desirable to provide an improved exercise storage apparatus which addresses the above described problems and/or which offers improvements generally. [0009] According to the present invention there is provided an exercise equipment storage apparatus as described in the accompanying claims. BRIEF SUMMARY OF THE INVENTION [0010] In an embodiment of the invention there is provided an exercise equipment storage apparatus comprising at least one shelf having a support surface; a support structure arranged to support the at least one shelf; and a plurality of stop members mounted on the support surface defining at least one storage zone for receiving said exercise equipment. The plurality of stop members are reconfigurable to selectively vary the position, size and/or orientation of the at least one storage zone. As such, the storage unit may be reconfigured to house an almost limitless range of exercise equipment. The entire storage unit may be configured to hold a specific range of equipment or configured, and may be reconfigured if that range is replaced with an alternative. The storage unit may alternatively be configured to hold a variety of different equipment on the same unit. This is advantageous for smaller gyms that hold smaller volumes of equipment. It also enables larger gyms to create storage pods with a variety of equipment provided on each pod, enabling the equipment to be distributed at multiple stations around the gym rather than the entire set of each range of equipment being located at a single location. [0011] The plurality of stop members are retaining elements and preferably cooperate in pairs to form a channel defining the at least one storage zone. A single stop member may cooperate with more than other stop member simultaneously in a paired arrangement. For example a stop member may have stop formations on two sides, with each side pairing with a different stop member. Typically a holding channel is sufficient to retain a piece of exercise equipment, and the channels may cooperate with retaining walls, lips or the like at the front and or rear edges of the shelves to retain the equipment. [0012] The stop members may comprise an elongate body having a stop surface extending along the length of the body. The shelves are preferably substantially square and the length of the stop members is preferably substantially equal to the length if the sides of the shelves such that in either the lengthwise or transverse orientation the stop members extend substantially across the entire depth or width of the shelf. [0013] Preferably the stop surface is inclined transversely to the length of the body to define a wedge formation. The wedge formation advantageously enables the stops members to cradle equipment having a rounded lower surface with the wedging action preventing rolling of the equipment in at least the transverse direction. [0014] The stop members preferably have a vertical rear wall extending along the length of the body on the opposing side to inclined wedge surface. This enables the stop members to be [0015] The pairs of stop members are preferably arranged parallel to each other with the inclined surfaces facing towards each other such that the storage zones have a substantially convex configuration in the transverse direction relative to the length of the stop members, thereby defining a substantially convex configuration. [0016] Each shelf preferably includes a plurality of connection points for securing the stop members to the shelf, the connection points being arranged to define a plurality of connection locations with the stop members being reconfigurable by selective securement to different connection locations selected from the plurality of connection locations. [0017] Each shelf preferably includes a front edge and an orthogonal array of connection points configured to enable the stop members to be secured to the shelf in a parallel arrangement to each other in which the stop members arranged parallel or transverse to the front edge of the shelf. The orthogonal array ensures that the stop members are only able to be secured to the shelf one of a transverse or longitudinal arrangement. Longitudinal is used here to refer to the axis defined front to back of the shelf. [0018] The plurality of connection points may comprise apertures extending through the shelf for receiving a corresponding connection member. The corresponding connection members may be spigots or lugs extending from the stop members, snap fit connections or threaded connectors provided through the shelf from the underside. [0019] The corresponding connection member is preferably a threaded fastener, and the stop members may include a plurality of threaded bores having a spacing corresponding to the spacing of the apertures of the shelf such that the threaded bores may be aligned with a selected plurality of connection apertures to receive a corresponding plurality of fasteners extending therethrough. This means of securing the stop members provides a secure connection which is essential where weighted equipment is being stowed, while also enabling the stop members to be removed from reconfiguration using a tool. [0020] The support structure preferably comprises an upright spine member and a base member, and wherein a plurality of shelves is secured to the spine. The use of a spine enables the shelves to be supported using only a single support member thereby reducing material, parts and cost, as well as maximizing access to the shelves with the spine being located at the rear of the shelves with full access to the front and sides, and providing an aesthetically pleasing design with the shelves having a floating appearance. [0021] A plurality of connection points are preferably provided along the height of the spine and the plurality of shelves are removably connectable to the plurality of the connection points to enable the height and/or relative spacing of the shelves to be selectively varied. As such equipment of varying heights may be accommodated. [0022] The spine preferably includes a front face and side walls, with the connection points being formed in the side walls, and wherein each shelf comprises a pair of spaced connection brackets extending from the lower surface configured to locate either side of the spine adjacent the side walls to connect the shelf to the spine. The shelf also preferably includes a retaining wall, lip or ridge at the front and/or rear edges. [0023] The connection brackets preferably each include a transversely facing connection plate extending downwardly from the lower surface of the shelf having a vertical rear edge and an angled forward edge with the connection plate tapering upwardly in the forward direction towards the lower surface of the shelf. The brackets are secured via connectors inserted through the brackets transversely into the side walls of the spine. [0024] The connection brackets may each include a flange plate extending downwardly from the rear edge of the shelf, a forwardly extending angular reinforcement plate connecting the base of the flange plate to the lower surface of the shelf, with the transversely facing connection plate being secured to the flange plate and the angular reinforcement member. This arrangement maximizes support of the shelves while minimizing material usage. [0025] The upper surface of the base is preferably provided with a plurality of connection points corresponding to the connection points of the shelves to enable the stop members to be secured to the base to provide one or more additional storage zones, thereby maximizing the storage efficiency of the apparatus. [0026] The spine preferably includes a forwardly angled lower section that secures to the base forwardly of the upper section and the base is arranged such that the rear edge of the base is aligned with the rear face of the spine. This ensures that there is a part of the base that extends rearwardly of the connection with the spine for maximum stability, while also ensuring that the apparatus may be placed in flush abutment with a wall with the spine flush with said wall, thereby optimizing the use of space. BRIEF DESCRIPTION OF THE DRAWINGS [0027] Various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: [0028] FIG. 1 shows a shelving assembly for weighted exercise equipment according to an embodiment of the invention; [0029] FIG. 2 shows a shelf of the shelving assembly of FIG. 1 ; [0030] FIG. 3 shows a view from below of the shelf of FIG. 2 ; [0031] FIG. 4 shows a stop member of the shelving assembly of FIG. 1 ; and [0032] FIG. 5 is a view from below of the stop member of FIG. 5 . DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0033] To facilitate an understanding of the principles and features of the various embodiments of the invention, various illustrative embodiments are explained below. Although exemplary embodiments of the invention are explained in detail, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the invention is limited in its scope to the details of construction and arrangement of components set forth in the following description or examples. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, in describing the exemplary embodiments, specific terminology will be resorted to for the sake of clarity. [0034] It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, reference to a component is intended also to include composition of a plurality of components. References to a composition containing “a” constituent is intended to include other constituents in addition to the one named. [0035] Also, in describing the exemplary embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. [0036] Ranges may be expressed herein as from “about” or “approximately” or “substantially” one particular value and/or to “about” or “approximately” or “substantially” another particular value. When such a range is expressed, other exemplary embodiments include from the one particular value and/or to the other particular value. [0037] Similarly, as used herein, “substantially free” of something, or “substantially pure”, and like characterizations, can include both being “at least substantially free” of something, or “at least substantially pure”, and being “completely free” of something, or “completely pure”. [0038] By “comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named. [0039] It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a composition does not preclude the presence of additional components than those expressly identified. [0040] The materials described as making up the various elements of the invention are intended to be illustrative and not restrictive. Many suitable materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of the invention. Such other materials not described herein can include, but are not limited to, for example, materials that are developed after the time of the development of the invention. [0041] Referring to FIG. 1 , there is provided a reconfigurable shelving assembly 1 for weighted exercise equipment. The shelving assembly 1 comprises a plurality of shelves 2 supported on a support frame 4 having a base 6 . The support frame 4 comprises a vertical spine member 8 that is preferably formed from rectangular hollow section steel or aluminum. The spine 8 includes an upright and preferably substantially vertical main support section 10 and a lower section 12 that is inclined forwardly. [0042] The spine 8 includes a front facing wall 14 , side walls 16 and a rear facing wall 18 . In use the front wall 14 is forwardly facing towards the user, and towards the front leading edge of the shelves 2 . The terms ‘forwardly’ and ‘rearwardly’ are relative and are used to refer to a direction towards or away from the leading edge of the shelves and the term ‘sideways’ refers to a direction transverse to the forward and rearward direction. The term ‘upwardly’ and ‘vertically’ are relative to the base 6 and refer to a vertical axis perpendicular to the planar upper face of the base 6 . [0043] The lower end 12 of the spine 8 is angled forwardly at an elbow 20 located approximately a fifth of the way along the height of the spine 8 . The lower section 12 secures to the base 6 at a connection point 24 which has a forward location relative to the main support section 10 . The base 6 forms a foot for supporting the spine 8 and shelves 2 such that the support assembly 1 is free standing. The forwardly inclined arrangement of the lower section 12 of the spine 8 allows a rear portion 22 of the base 6 to extend rearwardly of the connection point 24 with the lower section 12 such that the rear edge 26 of the base 6 is aligned with the rear face 18 of the spine 8 . This enables the support assembly 1 to be located flush against a wall with the spine 8 substantially abutting the wall without interference from the base 6 . The base 6 comprises a planar support plate which preferably extends forwardly at its front edge 28 a greater distance than the front edge of the shelves 2 to maximize stability. [0044] The shelves 2 are preferably formed from folded sheet metal such as steel or aluminum. As shown in FIG. 2 each shelf 2 includes a ridge 30 along the front edge 32 defining a forward retaining wall. The ridge 30 is formed by a v-shaped fold including an inclined surface 34 forming a wedge arrangement on the inner side of the ridge 30 and a vertical flange section 36 defining a flat front facing wall to the shelf. At the rear edge 40 a rearwardly inclined wall 42 is also formed to provide a wedge arrangement at the rear edge. The front wedge 34 and rear wedge 42 combine to define a concave profile across the shelf 2 along the longitudinal axis defined front to back of the shelf 2 . A flat section 44 is provided rearwardly of the wedge 42 , and a vertical flange section 46 extends vertically downwards at the rear edge of the shelf 2 . [0045] An array of apertures 43 is formed through the main planar section 45 of the shelf 2 . The apertures 43 are arranged in an orthogonal array with rows extending transversely and longitudinally across the plate. In the embodiment shown in FIG. 2 , four transversely extending rows are provided that are evenly spaced in the longitudinal direction. The apertures 43 along these rows also form longitudinally extending rows. Nine apertures are provided across the shelf 2 in the transverse direction such that nine longitudinal rows are defined. [0046] As shown in FIG. 3 , a channel 48 is defined midway along the rear flange plate 46 , with a corresponding cut away 50 being formed in the flat section 44 . The channel 48 has a width corresponding to the width of the spine 8 with the spine 8 being received in the channel 48 to secure the shelf 2 to the spine 8 . Either side of the channel 48 are provide longitudinally extending connection plates 52 having a plurality of apertures 54 arranged vertically adjacent the rear edge of the plates 52 . The size and spacing of the apertures 42 corresponds to a plurality of connection apertures 56 formed along the side walls of the spine 8 . The apertures 54 of the shelf 2 are aligned with the apertures 56 of the spine 8 and threaded fasteners or any other suitable connection means are passed through the aligned apertures to secure the shelf 2 to the spine 8 at a selected and variable height. The apertures 56 of the spine may include an inner thread formed by any suitable means to enable a threaded fastener to be screwed directly into the spine 8 . The connection plates 52 taper upwardly in the forward direction and provide bracing for the shelf in connection with rear flange plate 46 . Forwardly extending upwardly inclined plates 58 extend from the flange plate to the shelf 2 to provide further support, with the inclined plates being connected to the connection plates 52 . [0047] As shown in FIG. 4 , a stop member 60 comprises an elongate body 62 having an inclined stop surface 64 extending along its length. The stop member 60 includes a substantially vertical rear wall 66 , an upper edge 68 , a front edge 70 and end walls 72 . The stop surface 64 is inclined downwardly from the upper edge 68 to the front edge 70 in the transverse direction relative to the length of the body 62 , such that when viewed from the end the stop member 60 has a substantially right angled triangular cross sectional shape providing the stop member 60 with a wedged configuration. The stop surface 64 includes a textured grip surface having an integrally molded raised waveform pattern which increases the friction coefficient of the surface, thereby improving grip. Other surface texturing may be utilized to improve grip and/or the surface may be provided with a resilient coating or covering such as rubber to improve grip. A plurality of scalloped sections 74 are formed along the upper edge 68 having a substantially semi-circular shape to allow these sections to cradle a cylindrical bar such as a weight bar or a cylindrical handle or other component of an exercise device when supported on the upper edge 68 of two or more stop members 60 . A recess 76 is formed centrally along the stop surface 64 and front edge 70 that enables the wedged stop member 60 to more effectively cradle a spherical exercise apparatus such as a medicine ball. The recess 76 includes inwardly inclined front edge sections 78 and a section of the stop surface that is inclined downwardly at a greater angle than the rest of the surface. [0048] Longitudinal stops 79 are provided proximate either end of the stop surface 64 . The longitudinal stops 79 are preferably rubber or plastic blocks arranged to prevent apparatus rolling longitudinally past the ends of the stop member 60 . The blocks 79 are preferably removable and include spigots 81 extending from their lower surface that are inserted into corresponding recesses in the stop surface 64 to removably secure them thereto. [0049] A shown in FIG. 5 , the lower surface 82 of the stop member 60 includes a pair of attachment elements 84 for securing the stop member to a shelf 2 . The attachment members comprise cylindrical elements or bosses each having a threaded inner bore for receiving a corresponding treaded fastener. The body 62 of the wedged stop member 60 is preferably hollow as shown, with a plurality of reinforcing walls 86 supporting the threaded bosses 84 , and the stop surface 64 . [0050] Referring again to FIG. 1 , the stop members 60 are securable to the support surface 45 of the shelves 2 in a multitude of different configurations by aligning the attachment elements 84 with two correspondingly spaced apertures 43 . The array of apertures 43 is arranged such that the spacing of the apertures 43 corresponds to the spacing of the attachment elements 84 , with the spacing of the attachment elements 84 being a multiple of the spacing of the apertures 43 . In the shelf shown in FIG. 2 the spacing of the front and rear transverse rows of aperture 43 are spaced apart equal to the spacing of the attachment elements 84 . The stop members are therefore only locatable lengthwise in a single lengthwise position when oriented lengthwise, front to back, but are locatable in this longitudinal position at multiple transverse locations width wise by connection to corresponding pairs of apertures 43 along the front and rear rows of apertures 43 . The spacing of the apertures along the transverse rows is such the outermost apertures 43 at the ends of the rows are spaced apart equal to the spacing of the attachment elements 84 , such that when oriented transversely, the stop members 60 are only locatable width wise in a single width wise position but are locatable in this orientation at multiple locations lengthwise by connection to corresponding pairs of apertures 43 the longitudinal rows of apertures 43 . [0051] The stop members 60 may also be oriented transversely and secured in position in a similar manner by alignment of the attachment elements 84 with a correspondingly spaced pair of connection apertures 43 at the required location. As shown in FIG. 1 , the vertical back walls 62 of the stop members 60 allows them to be abutted back to back. To enable this the attachment elements 84 are located centrally in the transverse direction and the apertures 43 are spaced apart a distance equal to the width of the stop elements 60 , with the distance between the attachment elements of two stop elements back to back being equal to the spacing of the aperture 43 and equal to the width of one stop member 60 . [0052] Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

An exercise equipment storage apparatus having a number of shelves, each having a support surface. A support structure in the form of a spine is arranged to support the shelves. A plurality of stop members are mounted on the support surface. The stop members define at least one storage zone for receiving the exercise equipment. The plurality of stop members are reconfigurable to selectively vary the position, size and/or orientation of the at least one storage zone. As such, the storage unit may be reconfigured to house an almost limitless range of exercise equipment.

CROSS-REFERENCE TO RELATED APPLICATION The present application is a continuation of and claims the benefit of priority of U.S. utility patent application 11/286,905, filed Nov. 23, 2005, now U.S. Pat. No. 8,000,979, issued Aug. 16, 2011, which claims the benefit of priority of U.S. provisional patent application 60/630,937, filed Nov. 24, 2004. FIELD OF THE INVENTION The invention relates generally to the fields of healthcare and information technology. More particularly, the invention relates to a system for managing patients in a healthcare facility. BACKGROUND Existing systems for automating healthcare have focused on addressing the needs/desires of providers, not patients. As a result, patients often have to endure long waiting times and poor customer service. To alleviate this problem, a system is needed that both maximizes the efficiency of the healthcare process and provides patients easy access to their status and/or control of the process. SUMMARY The invention relates to the development of an automated healthcare system that addresses the needs and desires of both healthcare providers (e.g., patient service workers and clinicians) and patients. The system encompasses computer communications network-based systems, software, various input and output stations, and a patient identification device (e.g., an identification card, an RFID, or a smartcard) that work together to allow (a) providers to direct, track, and optimize the efficiency of patient activity, and (b) patients to have ready access to their status and, in some cases, control of the healthcare process. The system improves patient satisfaction by reducing wait times to be seen by a clinician and improving communication to the patient, patient service workers, and hospital management. By employing provider-accessible and patient-accessible information input/output stations such as a touch-screen kiosk, the system provides direct patient access to complete and accurate patient-specific information. The system also effectively establishes a process of managing waiting lines in any given area and then automatically and electronically linking to the next area. For example, for a patient visiting a healthcare facility for a physical examination and diagnostic radiology, after the patient has completed the check-in process (e.g., registration), the system can automatically place the patient in the queue for the physical examination or the diagnostic radiology. To enhance the efficiency of this process, the system preferably prioritizes which service is delivered first according to expected wait times. For example, if the expected waiting time for physical examination is longer than that for radiology, the patient would first be put on the radiology queue. On the other hand, if the expected waiting time for radiology is longer than that for physical examination, the patient would first be put on the physical examination queue. In one embodiment of the invention, an enterprise information system provides a real-time picture of the flow of patients throughout the organization. Patient service workers and clinicians can view the details of what is occurring in registration and treatment departments, thereby enabling them to make changes to improve the efficiency of patient flow (and thereby improving revenue generation). Patients are informed of their process stage and queue status through an information output device such as a large video display. The display may optionally be outfitted to display audiovisual entertainment, general medical information, points of interest, and advertisements. Accordingly, the invention features a system for managing a plurality of patients in a healthcare facility. The system includes at least one server communicatively connected to a computer communications network, the at least one server including at least one database having stored therein data relating to the plurality of patients, the data including (a) names of the plurality of patients, (b) names of at least two departments within the healthcare facility, (c) at least one listing of names of at least two patients of the plurality of patients who are queuing to visit one of the at least two departments, (d) demographic information pertaining to the plurality of patients, and (e) treatment status of each patient of the plurality of patients, the at least one server configured to receive input signals from and transmit output signals across the computer communications network to a network access device that is accessible by the plurality of patients and to a network access device accessible to staff of the healthcare facility, at least one patient identification card for facilitating checking-in to the healthcare facility by at least one patient of the plurality of patients, a means for determining an order in which the plurality of patients will visit the at least two departments, and at least one screen displaying the order in which the plurality of patients will visit the at least two departments that is publicly displayed within the healthcare facility. The network access device that is accessible by the plurality of patients can be, for example, a kiosk, video display, PDA, computer monitor, or television monitor. The network access device that is accessible to the staff of the healthcare facility can be, for example, a computer monitor or a television monitor. The at least one screen can further display advertisements, news and weather reports. At least a portion of the data stored in the database can be modified by at least one of the plurality of patients via the input signals conveyed across the computer communications network. The means for determining the order in which the plurality of patients will visit the at least two departments includes a computer program executing business rules. In another aspect, the invention features a method of managing a plurality of patients in a healthcare facility. The method includes the steps of: (a) providing at least one server communicatively connected to a computer communications network, the at least one server including at least one database having stored therein data relating to the plurality of patients, the data including (i) names of the plurality of patients, (ii) names of at least two departments within the healthcare facility, (iii) at least one listing of names of at least two patients of the plurality of patients who are queuing to visit one of the at least two departments, (iv) demographic information pertaining to the plurality of patients, and (v) treatment status of each patient of the plurality of patients, the at least one server configured to receive input signals from and transmit output signals across the computer communications network to a network access device that is accessible by the plurality of patients and to a network access device accessible to staff of the healthcare facility; (b) providing a means for determining an approximate amount of time each patient of the plurality of patients will wait before receiving treatment; (c) accepting at the server an input signal transmitted across the communications network from the network access device accessible to staff of the healthcare facility, the input signal including data such as (i) the name of at least one patient of the plurality of patients, (ii) the name of at least one department within the healthcare facility, and (iii) demographic information pertaining to the at least one patient, and storing the data included in the input signal in the database; and (d) transmitting from the server an output signal including at least a portion of the data included in the input signal and an approximate amount of time the at least one patient will wait before receiving treatment across the communications network to the network access device accessible by the plurality of patients. As used herein, the phrase “computer communications network” means a group of two or more computer systems communicatively linked together. For example, a “local area network” or “LAN” is a computer communications network where the linked computers are geographically close together (e.g., in the same building). A “wide area network” or “WAN” is another computer communications network similar to a LAN except that the linked computers are farther apart (e.g., they are in different buildings and connected by telephone lines or radio waves). A “global” computer communications network is one that is not limited to a certain geographical area or number of individual computers, but rather links computers throughout the world generally without restriction. The Internet is an example of a global computer communications network. As used herein, the term “server” means a computer or device on a network that manages network resources, e.g., processes data coming in from a computer communications network, to stores files in a database, and outputs files from a database over the computer communications network. Examples of servers include file servers, e-mail servers, and Web servers. “Computer program” and “program” mean a writing that sets forth instructions that can direct the operation of an automatic system capable of storing, processing, retrieving, or transferring information. When a computer program is entered into a computer system, it forms part of the system referred to as “software.” By the term “hardware” is meant physical components of a computer system. As used herein, a “Web site” is a site (location) on a computer communications network such as the Internet containing one or more Web pages. Most Web sites contain a “home page,” which is the main page of a Web site and usually the first screen users see when they enter the site. Home pages often offer an introduction to the material contained in the Web site and also an index or table of contents hyperlinked to related Web page documents of the site. By the term “user” is meant any individual or entity who accesses or uses the system of the invention. Unless otherwise defined, all technical and legal terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All patent applications mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the particular embodiments discussed below are illustrative only and not intended to be limiting. Other features and advantages of the invention will be apparent from the following detailed description, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are entity relationship diagrams. FIGS. 3 and 4 are flowcharts of an aspect of the present invention. FIG. 5 is a pair of diagrams showing master card and remote card systems. FIG. 6 is an illustration of a kiosk. FIGS. 7-36 are screen shots of an aspect of the present invention. DETAILED DESCRIPTION The below described embodiments illustrate various representative systems within the invention. Nonetheless, from the description of these embodiments, other aspects of the invention can be made and/or practiced based on the description provided below. An exemplary automated patient management system features a computer communications network-based system, software, various information input and output stations or devices (e.g., network access devices), and a patient identification device (e.g., identification card, RFID, smartcard). Software useful in the invention is configurable to allow customization to meet the needs of each healthcare facility, provides management of queues, sub-queues, and modalities with and without application of user-defined business rules to facilitate patient recognition, check-in and provide feedback, queue information, weather, news, and marketing information to the patient as well as customer service-like features to the patient to enhance the quality of their visit to the healthcare facility. The system provides real-time and, by virtue of its database, historical information to supervisory and managerial levels both to address real-time bottlenecks at all connected modalities and to identify the quality of the work effort of hospital employees. The input stations include two categories, those which enable the patient to directly interact with the system to initiate services related to their visit and to request information related to their visit, and those which enable hospital employees to better manage the patient queues to accelerate their entry into the healthcare facility. The input stations can be any Web-enabled or PC-connected device including personal computers, tablets, laptops, kiosks, card-readers (bar code, magnetic stripe, and smart card), bio-metric readers, RFID readers, etc. The output stations provide the patient with patient-specific information and status (e.g., patient scheduled visits, face sheets, etc.), patient queue information, patient instructions, weather, news, and marketing information (e.g., advertisements), healthcare facility news, and any desired content. Output stations also provide for health information and identification (e.g., Loyalty Card) production both at the facility and remotely at sites external to the healthcare facility (e.g., assisted living facilities, events, health fairs, etc.). These output stations include Web-enabled devices for delivery direct to the patient's computer as well as patient informational monitors, and identification card (e.g., Loyalty Card) printers. The input stations and output stations can be integrated into one device or they can be stand-alone devices. The patient identification device can be any suitable device such as an identification card, an RFID, and/or a smartcard, bio-metric device, and can adjust to utilize any magnetic stripe and/or bar-coded device. The identification device can also be placed on the patient's vehicle. The system is preferably configured to run on computer systems already in place at the healthcare facility, e.g., in a Windows/PC or UNIX-based environment. The operation of the system can be illustrated through a typical patient visit to a healthcare facility such as a hospital or clinic. The system begins capturing data on patient flow as soon as the patient arrives at the healthcare facility and oversees patient movement from registration through treatment to departure. The system has the ability to perform its initial capture direct from a patient's computer prior to the patient's arrival at the healthcare facility. In a preferred embodiment of the invention, the system features public screens that are displayed in different locations throughout the healthcare facility. By displaying patient queuing information, for example, the public screens can effect a dramatic reduction in patient questioning of the healthcare facility staff regarding how long they must wait before receiving treatment. These public screens can also display information that helps patients prepare for registration. The screens can be used as a marketing tool when set up to alternate between patient information screens and marketing messages (e.g., advertisements). Other examples of displays that can be viewed on the public screens are news and weather reports. Additional functionalities of the system of the invention are numerous. For example, ADT linkage automatically updates system files. When face sheets are provided, erroneous information is identified before they go to the registrars. A benefactor lounge can be incorporated that allows key contributors to sign-in and be routed from any location while they receive the attention the healthcare provider chooses to provide. A valet service which moves patients in and out of the healthcare facility more quickly and easily is also envisioned. Marketing system connectivity allows a patient service worker to download potential patient files and tie-in to marketing programs and strategies. Identification card (e.g., Loyalty Card) functions include use as a health information card. When used at the healthcare facility gift shop or cafeteria, the identification card may entitle the patient to discounts. Such use improves business, track attendance at meetings, and remote registration. EXAMPLE 1 Functional Hierarchy One embodiment of the system of the invention combines a patient services application and a marketing services application. In one variation of this embodiment, eight major functions are defined within the patient services application. These eight major functions are: 1) check-in patient, 2) select patient (automatic or manual, business rules, scheduled vs. unscheduled, card privileges), 3) expedite patient registration, 4) complete and route patient (automatic routing, manual routing, alert next department), 5) enhance communication to patient, 6) communicate status to hospital administration and staff, 7) communicate patient information to external entities, and 8) maintain system. In this system, a patient is provided a number of options to facilitate check-in to the facility by the use of an identification device (e.g., a bar-coded loyalty or identification card). The identification device can be delivered to the patient at check-in or preferably has already been placed in the possession of the patient, e.g., on a prior visit, at an event or from a marketing-related mailing. If the patient is not in possession of a bar-coded identification card (e.g., Loyalty Card), the receptionist checks the patient into the system by entering the patient's name. Check-in can be facilitated with the identification device or any other suitable identifying method, e.g., biometric (e.g., fingerprinting) or electronic methods. Regardless of the method used to check-in, the patient's name can be displayed on a Patient Tracking Display in the waiting area in addition to the receptionist and registrar workstations. In some embodiments of the system, the patient has the ability to check-in to the facility before arrival by using a remote check-in function allowing the patient to enter an identifier such as a Loyalty Card number via a Website or a voice/touchtone-enabled telephone check-in. Check-in can also be accomplished when a patient is being transported in either a planned transport or an emergency transport situation. In some embodiments of the invention, input devices such as personal digital assistants (PDAs) with wireless connection to the network and the check-in application software can be provided to parking valet personnel to check-in the patient as they leave their vehicles to be parked. The valet can enter the patient's identifier into the PDA to check the patient into the system. Kiosks located at select sites within a healthcare facility and a community can be used for self check-in to the facility. For example, the patient can enter his identifier (e.g., swipe a Loyalty Card) and electronically sign on a signature pad or touch screen (such as one on a tablet PC or like device) to notify the system of his arrival, so that the system can automatically place the patient in the queue for the appropriate services. In some embodiments, the patient's name is displayed on a Patient Tracking Display (e.g., a video output) in the waiting area in addition to the receptionist and registrar workstations. An animated display in one corner of the kiosk's display guides and shows the patient the proper way to enter his identifier. Other features of the check-in portion of the system might include: a) import capabilities from the scheduling system enable the system to recognize the patient has a scheduled appointment; b) the ability to check-in to hospital events and marketing events, e.g., physician mixers and classes (such a system can hold data on which non-clinical events persons have attended by establishing an appropriate queue to capture attendees, counting and identifying who shows for an event); c) the ability to check-in to a physician's office or clinic; d) the ability to check-in a patient when arriving at the treatment department; e) identification card number look-up function for patients with cards but who forgot to bring them; f) patient pictures display at check-in with Loyalty Cards for patients that have had a previous treatment; g) the ability to register a patient in the patient's own language; h) captured signature can populate all necessary registration forms; i) wireless check-in by the registrar; and j) voice and handwriting recognition. In preferred embodiments of the system, the patient services application is linked to the facility's security system to enable the patient access to a particular department or area within the facility. For example, a patient's identification device might be used as a key to unlock pre-selected doors. In this embodiment, only patients authorized by the system have the ability to unlock the pre-selected doors. Once the patient has been checked-in (registered), a registrar or technician can select the next patient for registration in a registration area or for treatment at an ancillary department. This selection can be either by an automatic or manual method. The system provides for automatic system selection of “Next Patient” by virtue of its internal business rules engine (e.g., a scheduled patient may find himself with an increased priority as he approaches his scheduled time) and the system provides for manual selection for hospital employees to select from any patient residing in their assigned patient queue. Business rules can be applied to prioritizing which patients are selected that allow department management or administration to customize processing of information based on specific business rules or policies, e.g., patient placement on the check-in queue, notifications, VIP and special handling, scheduled vs. unscheduled, card privileges, management and administration notifications, status queue changes and wait time issues, user-configurable, and patient alert if a patient has not completed visits to all ancillary departments. In a representative embodiment of the system, a patient's name can change color (e.g., normal -> yellow -> red) on a Master Administrative Screen of the system based on the elapsed time that a patient has remained in the queue in Checked-In Status based on user-definable time increments. The status of the patient record can be displayed as follows: YELLOW—after a set period of time has elapsed from check-in; RED—after an elapsed period of time from the change to YELLOW; and change to RED status can generate an e-mail notification to the appropriate department management. The presence of the patient's identifier (e.g., account number) on the identification device provides the registrar faster access to the patient's current demographic and insurance information from the information system that is used to register the patient. Although color is used in this example to indicate patient status, any suitable indicator can be used (e.g., text, symbols, shapes, etc.). The identification device's patient identifier (e.g., a card having an identifying bar code) can be linked to the patient's medical record number to expedite the registration process by providing the patient the ability to update his demographic information without the involvement of the registrar. This can be accomplished by providing a capability for the patient to enter his information from either his own computer or a hospital resident computer where the registrar would only need to perform a validation function. The system also provides for automated update by virtue of its many import capabilities including File-Transfer and HL7 connection to any existing Hospital Information System (HIS) and by connection to any external data source which the hospital has requested to be loaded. If the patient decides not to self-register, the registrar can have access to updated demographic data provided by the patient on the facesheet (e.g., the general information related to each patient including demographic, address, and personal information printed by the kiosk). To verify and retrieve a patient record, in one embodiment of the system, a patient swipes his identification card (a Loyalty Card, a driver's license, an insurance card or a credit card) into an input device to activate the system to access the patient's demographic information stored from a previous visit. The system can store static information such as demographic and clinical information, e.g., nutrition, special needs, blood type, advanced directives, organ donor, consent, insurance, allergies (e.g., food and drug), Medicare Advance Beneficiary Notice, Medicare Secondary Payer, PCP's UPIN, and a record of who/when accessed this information. In some embodiments of the system, a patient can request and review his registration information via a paper format printed by the kiosk. This assists in reducing the time with the registrar by reviewing and updating the information while waiting to see the registrar. Such a process can include the following steps. Upon swiping their card at the kiosk, the patient selects the option to review their information prior to Registration. The system requests the “face sheet” data from currently existing systems at the facility which contain this information, and then prints the information out for the patient. The patient reviews and corrects the information on the sheet, signs the sheet in the appropriate space, and brings that sheet with him when he goes to see the registrar. The registrar then updates only those fields that have changed. Once the patient has verified his personal/demographic information without the aid of a registrar, the patient has the ability to register. The patient interacts with a kiosk screen instead of a registrar to accomplish the following functions: a) swipe card, capture signature and print forms; b) point of service registration by routing all pre-registered patients to point of service; c) automatic transfer from registration queue to treatment department; d) ability to know patient account status; e) use of fingerprint in addition to/in lieu of bar code; and f) use Hospital or multi-facility card to check-in. The system can also provide the ability for server-to-server connectivity to allow a single Loyalty Card to work within a health network. The identification on a card identifies the health organization as well as the individual facility. If a patient from one facility comes to another facility, the server detects that they shared the same health network and can send a request to the appropriate server which does an ADT retrieval and send the information in a HIPAA-compliant method to the requesting server where a facesheet can be printed out to facilitate registration using this information. Upon completion of registration, the registrar or the system can indicate that delivery of a particular service to a patient is complete and then can route the patient to the next department. An alert can be sent to the next department that the patient will soon arrive. An alert can also be sent to the preceding department that it is ready for the next patient. As described above, a Patient Tracking Display can be used to show the names of the patients in the waiting area, providing estimated wait times showing current wait times in addition to the capability to display green/yellow/red indicators that have been determined and configured within the system. This display can have multi-language display capabilities. Some embodiments of the system allow inquiry into wait times. For example, a patient identifier can be used as a key to access components of the system remotely via the internet or a telephone—voice response system to acquire information and a status update. A website can be used for a real-time inquiry to the current wait times, and can contain logic to look at the historical basis and recommend times when the wait time is lowest. The system might provide these additional functions: auto alert throughout the facility so that a patient does not need to wait in the waiting area for his turn to be called, Internet café hooked up to system (to keep patients occupied during waiting time), and auto-notification of delays in appointments to a patient's network access device of choice. The input/out devices (e.g., kiosks) of the system can provide a variety of information services to the patient, e.g., a) print maps and directions to different departments within the hospital and to hospital-associated facilities and physicians outside of the hospital, b) itinerary/where to go, c) kiosks having a touch screen with major areas as buttons and when pressed, an Itinerary and a map is displayed on the screen and available for printout, c) physician directory, d) Internet access, e) print patient demographics verification form, f) patient financial responsibility and account status, g) facility directory, discount coupons by card type, and wait time, h) products/services look up, i) in-house department and physician contact information with pictures of physicians and key individuals, j) department and clinic hours, k) outside physicians' directory, I) marketing content displayed on Patient Tracking Display or the ability to run an advertising window on a Patient Tracking Display in conjunction with the patient status, m) on-line application for Loyalty Cards, n) copies of test results over the Web (e.g., using Loyalty Card number), o) access to/from physician and service provider offices (a functionality that allows linkage between Loyalty Card and patient information maintained in a hospital's systems for physician office look up of patient face sheet information through the use of the Loyalty Card Number), and p) the Patient Advantage Room Function. The Patient Advantage Room Function includes: a) a separate room, b) use of a swipe card to open the door to the room, c) gold and platinum feature providing free beverages, and d) snacks and screens in the room showing the queues around the hospital. In this embodiment, a service person sits in the room, swipes the patient's card, and puts the patient into the appropriate queue, and has access to an inquiry dashboard so that they can give the patient the current average wait time. This room would be for those, for example, who have multiple tests that day, or a place to go to after a test. Various embodiments of the system can also feature a patient locator function that provides the ability to locate a patient who has checked-in through a registration area for treatment. This tracks the “path” of the patient through the care event and locates the last point of contact (information desk “patient finder”). As described above, the system can be set up to communicate a patient's status to a healthcare facility's administration or staff. For example, the system can be set up so that administration is notified of the arrival of a Board member or other VIP at check-in by e-mail and/or pager messages. In some embodiments of the system, the appropriate department management is notified of excessive patient waiting times by e-mail and/or pager messages. In one embodiment, once the patient has completed the healthcare facility visit and is ready to leave the facility, an e-mail message is sent to the PDA of the healthcare facility's valet. This enables the valet to have the patient's vehicle ready at the entrance to the facility. Valets are preferably provided with equipment which can recognize Loyalty Cards. In this embodiment, a patient arrives, their card is recognized, a valet welcomes the patient by name, provides the patient with a current parking card and parks the patient's car. When the patient is ready to retrieve his car (potentially at the treatment location), he swipes his card and chooses to get the car ready. The valet is then notified to get the car and parks the car in one of the loyalty parking spots. When the patient arrives, he has his card scanned to confirm ownership, receives his keys, walks to his car, and departs without having to wait. To facilitate archival, reporting and analysis functions (e.g., provide tracking and performance data), in one embodiment of the system, the database maintains data for swipe-in times at registration and ancillary departments. This process typically includes MIS Reports, sign-in logs archive of the signatures, export to spreadsheet, real-time statistics, and Patient Flow Simulator (to take historical production information and use it for simulations changing individual components of the day's activities). Based upon MIS reporting, an area of possible congestion/slow-down is identified. The simulator provides some possible causes for the slow-down staffing. An authorized hospital employee selects one of the “system-identified” resources to change. The system calculates and demonstrates how the change in that resource affects patient time. The system includes automatic notification to the I.T. (information technology) or technical support staff (by e-mail) of processing or database errors if and when they occur as well as an audit trail. The audit trail provides the ability to track specific types of transactions within the patient services application for audit and issue resolution purposes. This audit functionality can be implemented as a history table which can store the following: department identifier, date/time, transaction type, transaction detail, audit reason code, and user identifier (person performing the action). When the auditable transaction is performed, the required information is copied to a record in the audit history table, and prior to completing the transaction, the user is presented with a user identifier window to identify who was making the transaction, and a reason code. The system includes methods of communicating patient information to external entities. For example, e-mail notifications can be sent to external entities and business partners indicating that a patient has been registered at the facility. In some embodiments of the system, the patient can request taxi service. To summon a taxi to the facility to take them home, the patient swipes their card and the swipe generates an e-mail message which is sent to a participating taxi service that notifies the dispatcher to send a taxi to the facility for the patient. Upon completion of treatment, the patient swipes their Loyalty Card and selects taxi request. The system sends an e-mail and/or fax to the designated taxi service providing the patient's name and the location at which to pick up the patient. The patient accomplishes the request without having to go to a phone, asking someone to make the call, or having to pay for the call. To notify a physician's office that the patient has been registered at the healthcare facility, the patient's primary care physician or other physician can be alerted by e-mail that the patient has been registered at the facility for treatment or tests. In some embodiments of the system, suppliers can be alerted by e-mail that the patient may require certain services such as oxygen. The patient's pharmacy can be notified that prescriptions have been requested by the healthcare facility. As described above, the system provides a pre-installation function that can identify a communication/network method (wire/wireless), set-up parameter values, and establish patient flows. The capability is provided to establish and maintain the following system tables: queues, personnel, comments, routing, business rules, and audit capability. In a system of the invention, eight major functions are defined within the marketing services application. These functions include: set-up batch system, receive and place batch files, to automatically process batch files, export data (outside bulk priming, marketing database upload), register patient, produce remote Loyalty Cards, modify master records (update patient information in card database, activate/deactivate card), and support marketing initiative. Within set-up batch system are the following three functions: configure card, configure and start card service, and configure and start polling service. In some embodiments of the system, a configure card function provides the capability to select the fields that will print on a card, in effect creating a card template. In this system, the function of the card service module is to receive records from the polling service, validate the record, update the marketing services database if certain criteria match, and print the cards where indicated as determined by INI file settings. The card service configuration values are defined and stored in the card services INI file. The function of the polling service in this system is to poll the directories and when valid records are found in these specific directories, the polling service sends the record to the card service. The polling service configuration values are defined and stored in the polling services INI file. In some embodiments of the system, the receive and place batch files function imports batch records into the marketing services master database by placing them into a directory that has been identified on the server running the application. These batch files are in a specific format and can be from various sources such as an external marketing or CRM system. Additional sources may include associates lists, employee lists, physician's list, and others. The automatically process batch files function continuously polls the input directories checking to see if any files have been copied or moved into these directories. As soon as the batch files are placed in the specified directories, the marketing service application reads each record in the files and begins the processing depending on the configuration of the polling service INI file. This automated process performs a match for every record read from the batch, and for every match then based on the configuration established will: Insert Only (insert when no match, no action on match), Insert/Update (insert when no match, update when match), and No Action. For each record processed, a print option is performed depending on the configuration: Print on Insert, Print on Update, Print on Match, or No Print. Optionally, the data is saved. In this system, the marketing services application has the ability to export all or part of the database for outside bulk printing of Loyalty Cards in addition to being able to support an upload to an external Marketing Database. Two major functions are defined within Register Patient. The Receive and Store HIS Data function receives ADT (admission, discharge and transfer) information from the hospital information system and stores relevant demographic information to be used by the marketing services application. The Produce Loyalty Card function entails searching the database and allows the selection of which card is to be printed in addition to a selection screen which allows the selection of which fields are to be printed on the card to create a basic or full card. The cards preferably do not contain any patient-identifiable information, so there are no privacy concerns if the card is lost. In one embodiment of the system, four major functions are defined within Produce Remote Loyalty Cards: set-up remote PCs, register customers and patients, print cards, and update master system from remote. The Set-up Remote PC's function provides the capability to export records from the marketing services master database into a laptop's remote database so that the two databases are synchronized at the time the laptop is scheduled to be at the remote event. The Register Customers and Patients function gathers patient/loyalty data at community events for remote data entry and pre-registration in the field. This information is loaded into the marketing services master database so that when the patient arrives at the hospital, he is recognized by the patient services application. In this embodiment, physician office data entry allows for pre-registration and loyalty tracking, as well as the gathering of pre-registration information at the initial point of contact. This function can also be extended to attendance event counting, providing the ability to take a laptop, load the current marketing services master database and go to a hospital event, read attendees' cards as they arrive, as well as keep track of counts. Additionally, information can be provided to marketing such as the number of events, a person's name, personal info, etc. The Print Card function provides for a card being produced for the patient once the registration function has been completed. In addition, the capability is provided to search the remote database and allow the selection of which card is to be printed in addition to a selection screen which allows the selection of which fields are to be printed on the card to create a basic or full card. The cards preferably do not contain any patient-identifiable information, so there are no privacy concerns if the card is lost. The Update Master System from Remote function provides the capability to export the records from a laptop's remote database into the marketing services master database so that the master database contains the updated records from the remote event. In one embodiment of the system, the Modify Master Records function provides the ability to update patient information in the marketing services master database. Existing records can be updated or flagged as deleted as well as the ability to activate/deactivate so information can be corrected and the integrity of the database maintained. This database maintenance functionality can also be extended to a remote Customer Service organization as well as providing a Web-based Loyalty Card Request form that can be used by a prospective patient to request a Loyalty Card by submitting the necessary information required to provide the card. Systems described herein can include a support marketing initiative. Two major functions are defined within a support marketing Initiative. The Develop Custom Reports function is a Report Writer function that enables custom reports to be defined and run against the marketing services master database. This Report Writer relies on flexibility to create ad hoc reports as well as to potentially acquire predefined standard reports. The Print Coupons function provides the capability to produce discount coupons that can be used or redeemed at the facility. In various embodiments of the invention, the system supplements and supports marketing systems and is a tool in support of marketing departments. This is because current hospital systems have medical records systems where everyone must have a medical record number, almost always meaning they have visited the hospital at least once. The system of the invention, however, can hold information on potential visitors as well as those who have visited. While hospitals will export data from their main HIS and send the data to marketing companies, the system of the invention provides for the importing of files and holding of the information. This may provide registration improvement by allowing data from the system to automatically import to the main HIS. An Entity Relationship Diagram is shown in FIG. 1 . This diagram depicts the database construct for the patient services application. The Entity Relationship Diagram shown in FIG. 2 depicts the database construct for the marketing services application. As described above, one embodiment of the system of the invention combines a patient services application and a marketing services application. In this system, the patient services application electronically checks-in a patient for registration, and then, upon completion of the registration process, notifies the receiving treatment department and tracks patient progress as the patient moves through the patient care event. The marketing services application captures and holds data for each identification card (e.g., Loyalty Card) holder. The marketing services application allows for the individual and batch membership information entry for cardholders, and the printing of cards, either individually or in a batch mode. The data that is contained in each identification card's record can be added and/or updated three different ways: the data can be imported using a batch process, imported by an HL7 ADT interface, and by a Remote Event Membership Entry function. In some embodiments of the system, the patient services application has four primary system components: a) a check-in device that allows the patient to either check-in automatically using a Patient Identification Card, or manually if the patient does not have a card (e.g., this is a first time visit), b) a Patient Tracking Arrival Display identifying patients in an appropriately secure fashion, c) workstation-based administrative functions that allow the registrar to select patients for registration, and notify the treatment department once registration processing has been completed, and d) the system electronically captures and stores the patient's signature along with the date and time information, eliminating the requirement for a paper patient sign-in sheet. Upon completion of the registration process, the application notifies the “receiving” ancillary treatment department that the registration process is complete and that the patient is “in-transit” to that department, effectively setting them up automatically for check-in. At the ancillary treatment department, the process resumes with the patient presenting himself to the department receptionist and checking in to that department and modality (if applicable). The receptionist and treatment department personnel then process their patient queue similar to registration queue processing. When treatment is complete, the ancillary treatment department can either close out the patient record or continue by notifying the next treatment department that the patient is in transit, and the process repeats. In some embodiments of the system, the marketing services application has four primary system components. A first component is a Card Print Request. This function can be used mainly by the various registration areas and by other areas of the facility that need to generate individual cards. This function allows for the on-demand printing of individual card information already contained within the identification card (e.g., Loyalty Card) database. A second component is a Remote Event Membership Entry and Print. This function can be used by various departments to take the identification card (e.g., Loyalty Card) system to off-site functions and events so identification card membership can be promoted and entered into the system. When an identification card membership is entered into the database, a card is generated for the individual who provided the membership information. Once this information is collected, the remote system is brought back to the facilities Data Center where the data can be added into the Master identification card database. A third component is an Import and Export of the Database. This function allows identification card records to be passed between the Master database residing on the server and the Remote database residing on the Laptop computer(s) to be used for identification card membership collection at off-site functions and events. A fourth component is a Membership Batch Processing. This function is the processing of identification card membership information in a batch format. These batches can be from an external Marketing System or from other internal systems such as payroll or volunteer lists. In the system, the marketing services application relies on these aforementioned back-office processes such as the HL7 data feed, the Membership Batch Processing function, and the Master & Remote Database synchronization to enter the data into the identification card database for printing and searching purposes. The marketing services application can also be utilized by the patient services application to obtain data related to the unique identification card number that is generated and maintained by the marketing services application. EXAMPLE 2 System Overview Describing one embodiment of the system of the invention, the integration of the system of the invention into the registration business process flow of the healthcare facility is illustrated in FIGS. 3-5 . As shown in FIG. 3 , the patient has the option to check-in to the registration process using a Patient Identification Card (e.g., Loyalty Card) either at a check-in kiosk in the registration waiting area, or at the registration reception desk. The patient is asked to swipe his or her card, and then is instructed to electronically sign-in to complete the check-in process. If the patient does not have an identification card, the patient's name is entered into the system and the patient is requested to sign-in to complete the check-in process. Patients that do not have an identification card can receive one as part of the registration process for use on their next visit. Once the process is completed for either scenario above, the patient's name is placed in the registration queue for registration processing and a patient identifier is placed on a tracking board in the waiting area. For example, if the patient is registering for a radiological exam, upon completion of the registration process, notification is automatically sent to the radiology waiting area that registration has been completed, and the patient is listed in “swiped” status on the Radiology Status screen. When the patient reaches the radiology waiting area and presents himself for check-in, the patient identifier gets placed on a tracking board in the radiology waiting area, as depicted in FIG. 4 . If the patient is registering for an appointment with another ancillary department, upon completion of the registration process, notification is automatically sent to that ancillary department that registration has been completed, and the patient is listed in “swiped” status on that ancillary department's tracking screen. When the patient reaches that ancillary department waiting area and presents himself for check-in, the patient identifier gets placed on a tracking board in that department's waiting area. Typically, the marketing services application uses a Services Oriented Architecture. The services are using a stand-alone HTTP server and communication via SOAP/XML interfaces ( FIG. 5 ). Preferably, only the Card Service module talks with the database and all other applications (including the Polling Service) communicate with the Card Service module. In some embodiments of the invention, the marketing services application HL7 Interface is Level 2.2 using TCP/IP protocol. In various embodiments of the invention, the system server software runs on Microsoft Windows 2000 Server or Windows 2003 Server platforms utilizing Microsoft SQL 2000 Server. System client software typically runs on Microsoft Windows 2000 Professional, Microsoft Windows XP Professional and Microsoft Windows XP Tablet Edition. The system software can be shipped with the following User Guides: System User Guide, Identification Card (e.g., Loyalty Card) System Installation Guide, Identification Card (e.g., Loyalty Card) System Remote Installation Guide, Identification Card (e.g., Loyalty Card) System Registration User Guide, Identification Card (e.g., Loyalty Card) System Remote System User Guide, and Identification Card (e.g., Loyalty Card) System Batch System User Guide. EXAMPLE 3 Overview and Patient Flow of One Embodiment of the System The Patient Tracking Application electronically checks-in a patient for registration, and then, upon completion of the registration process, notifies the receiving treatment department and tracks patient progress as patients move through the patient care event. The two queuing processes for registering and treatment are linked. By linking these two processes, patients who are going to many departments during a given visit have their waiting lines for either registration or treatment connected during their entire visit. Within the check-in process, the system has four primary components: a) a check-in device that allows the patient to either check-in automatically using a Patient Identification Card, or manually if the patient does not have a card (e.g., this is a first time visit); b) a Patient Arrival Display Board identifying patients in an appropriately secure fashion; c) workstation-based administrative functions that allow the registrar to select patients for registration and notify the treatment department once registration processing has been completed; and d) electronically capturing and storing the patient's signature along with the date and time information, eliminating the requirement for a paper patient sign-in sheet. Upon completion of the registration process, the application notifies the receiving treatment department that the registration process is complete and that the patient is in-transit to that department, effectively setting them up automatically for check-in. At the treatment department, the process resumes with the patient presenting himself to the department receptionist and checking-in to that department and modality (if applicable). The receptionist and treatment department personnel then process their patient queue similar to registration queue processing. When treatment is complete, the treatment department can either close out the patient record or continue by notifying the next treatment department that the patient is in transit, and the process repeats. Patients with Patient Identification Cards are able to check-in to registration using their identification cards at kiosk stations, located near the entrances to the Outpatient Registration and Admission Departments. A kiosk main screen is shown in FIG. 6 . In a typical registration process, the patient approaches the kiosk, where a Welcome screen ( FIG. 7 ) is displayed. The patient swipes his or her identification card in front of the bar code reader. The identification card (e.g., Loyalty Card) number displays in the space provided below the “Please Swipe Identification Card” message. In the event that the kiosk is unable to read or recognize the Identification Card, the message: “Card ID not recognized Please go to the Desk for assistance” is displayed on the kiosk screen. The patient then presses either the Blue key to continue with the check-in process, or the Red key to cancel the check-in process, setting the kiosk for the next patient. Upon pressing the Blue Continue Button on the Welcome screen (on the previous page), the patient Sign-In Screen ( FIG. 8 ) is displayed on the kiosk. If the patient has a scheduled appointment, this screen also acknowledges the scheduled time of the appointment. If the patient is a walk-in without a scheduled appointment, the screen appears the same, without the line acknowledging the scheduled appointment time. The patient is instructed to electronically sign his name on the electronic sign-in interface. The patient presses the Blue button to continue the check-in process. Preferably, pressing continue without signing in presents a message to sign-in before proceeding. Pressing the Red Button cancels the check-in process and returns the patient to the main kiosk screen. Pressing the Clear button clears the signature pad and allows the patient to re-sign. Upon pressing the Blue continue button on the Sign-In Screen, a Check-In Confirmation Screen ( FIG. 9 ) message is displayed indicating the patient identifier that is displayed on the Patient Arrival Board for patient reference and instructing the patient to have a seat in the waiting area and wait to be called by a registrar. Pressing the Red Return button returns to the Signature Screen with a blank signature space to either re-sign, or to cancel the check-in while pressing the Blue Finish button on the Confirmation Screen clears this screen and presents the Welcome Screen ( FIG. 7 ) for the next patient. If a patient that has already checked-in swipes an identification card for a second time, the Duplicate Check-In screen ( FIG. 10 ) is displayed indicating that the patient has already checked-in, and presenting a reminder of the patient's screen identifier as it appears on the Patient Arrival Screen. If a patient has checked-in, but does not remember his or her patient identifier, having them re-swipe their card presents this screen and the Identifier information. Pressing the Blue Finish button clears this screen and presents the Welcome Screen for the next patient. In order to accommodate patients who may not have a Patient Identification Card, or where they may have forgotten their card, Sign-in Tablet (PC's) have been set up with the registration receptionist. These tablets maintain the same swipe functionality for patients with Patient Identification Cards as the kiosks. Additionally, these tablets also provide the ability for the receptionist to type in the patient's name on a virtual keyboard and then have the patient sign-in electronically. An example of a Tablet main screen is shown in FIG. 11 . If the patient approaches the Receptionist Counter with a Patient Identification Card, the patient swipes the card, and the number is displayed in the space provided. If the patient does not have a Patient Identification Card, the Receptionist types in the patient's name, using the keyboard attached to the tablet, and has the patient verify the spelling. The patient then presses either the Blue button to continue the check-in process, or the Red button to cancel the check-in process. From this point forward the process is the same as if the patient was checking in at a kiosk, a patient with a scheduled appointment is confirmed as above, and the patient is requested to electronically sign-in and press continue. Upon pressing the Blue Continue Button on the Tablet Welcome Screen, the patient Sign-In Screen ( FIG. 12 ) is displayed. If the patient has a scheduled appointment, this screen also acknowledges the scheduled time of the appointment. If this is a walk-in patient without a scheduled appointment, the screen appears to be the same, without the line acknowledging the scheduled appointment time. The patient is also instructed to electronically sign-in their name on the electronic sign-in interface. Pressing the Blue button continues the check-in process. Preferably, pressing continue without signing in presents a message to sign-in before proceeding. Pressing the Red Button cancels the check-in process and returns the patient to the main kiosk screen. Pressing the Clear button clears the signature pad and allows the patient to re-sign. Upon pressing the Blue continue button on the Sign-In Screen (on the previous page), the Check-In Confirmation Screen message shown in FIG. 13 is displayed. This screen indicates the patient identifier that is displayed on the Patient Arrival Board for patient reference and instructs the patient to have a seat in the waiting room and wait to be called by a registrar. Pressing the Red button returns to the Signature Screen with a blank signature space to either re-sign, or to cancel the check-in. Pressing the Blue Finish button clears this screen and presents the main kiosk screen for the next patient. If a patient that has already checked-in swipes a Loyalty Card for a second time, the Duplicate Check-In screen ( FIG. 14 ) is displayed, indicating that the patient has already checked-in, and presenting a reminder of the patient's screen identifier as it appears on the Patient Arrival Screen. If a patient has checked-in, but does not remember his or her patient identifier, having them re-swipe their card presents this screen and the Identifier information. Pressing the Blue Finish button clears this screen and presents the main kiosk screen for the next patient. The system features patient tracking application functions. The Master Administrative Screen is used to track and process the patient through both the registration and/or ancillary treatment department processes. Both versions of the Master Administrative Screen process the same way with some additional functionality that has been enabled for the ancillary treatment departments to allow for local patient check-in to the ancillary treatment department and modality queue. The functionality for the registration department is explained in the next section. The Registration—Master Administrative Screen ( FIG. 15 ) displays on the Registration Reception Desk Workstation for the receptionist or registrar to “work” the patient through check-in and registration, forward the patient to the treatment department, correct mistakes, and perform utility functions within the application. Once a patient has checked-in to registration via the kiosk or tablet functions, the patient is now in the Patient Tracking Application and is processed using the screen functions shown beginning in FIG. 16 . The registrar (or receptionist) presses the NEXT PATIENT button on the Registration side of the Master Administrative Screen. The next patient in the Queue for Registration Processing screen ( FIG. 16 ) is displayed. Upon identifying the patient in the waiting area, the registrar selects his or her ID from the dropdown list of registrars and presses the YES button. The patient name is removed from the Patient Arrival Board, and the patient status is changed to “in process” in the system. Selecting NO returns the receptionist to the Master Administrative Screen. In some instances, the next sequential patient may not be ready or available for the registration. In these cases, the Patient From List button is used to select the next patient. The registrar (or receptionist) presses the PATIENT FROM LIST button on the Registration side of the Master Administrative Screen which then displays a selection list ( FIG. 17 ) of all “in-process” patients for the registrar to choose from. Highlighting the patient moves the patient down to the confirmation area. Upon identifying the patient in the waiting room, the registrar selects his or her ID from the dropdown list of registrars and presses the YES button. Pressing YES removes the patient name from the Patient Arrival Board, and the patient status is changed to “in process” in the system. Selecting NO returns the receptionist to the Master Administrative Screen. The registrar (or receptionist) presses the PATIENT DONE button on the Registration side of the Master Administrative Screen. This screen ( FIG. 18 ) displays a selection list of all “in-process” patients for the registrar to choose from. Highlighting the patient moves the patient down to the confirmation area, where the registrar will: a) confirm the registrar ID—in case the registrar has changed, and b) enter a comment code for this patient registration if necessary. Pressing YES displays the Send To Department screen ( FIG. 19 ). Selecting a department on this screen sends notification to the receiving department that the patient is on his or her way for treatment and sets the patient to “in transit” status on their master screen. If the Send To department is not displayed, then the “Done” button can be selected to change the patient status to completed. Pressing NO returns the registrar to the Master Administrative Screen and leaves the patient in in-process status. The Ancillary Treatment Department—Master Administrative Screen ( FIG. 20 ) displays on the Ancillary Treatment Departments Reception Desk Workstation for the Receptionist or Tech to “work” the Patient Check-in Queue, correct mistakes, and perform utility functions within the application. Upon presenting himself at the Treatment Department waiting area, the Receptionist presses the ANCILLARY DEPT. CHECK-IN button on the Treatment Department side of the Master Administrative Screen. A List of patients that are “in-transit” from registration or another treatment department is displayed for selection. Upon identifying the patient, the receptionist performs the following steps: selects his or her ID from the Dropdown list of Ancillary staff, and assigns the patient to a Modality Queue if applicable from the dropdown list of available modalities for that treatment department. Pressing YES moves the patient from “in-transit” (swiped) status to Checked-in within the Department and Modality. The patient name is added to the Patient Arrival Board, and the patient record is updated as “Checked-in” in the system. The patient name is also displayed on the QueueView Screen for the Department (or modality) as checked-in and awaiting treatment. Selecting NO returns the Receptionist to the Master Administrative Screen with no change to the patient tracking record. If the department processes its patients on a first in-first out basis, the Next Patient function is used. This typically is not for departments where multiple modalities exist. The receptionist or tech presses the NEXT PATIENT button on the Treatment Department side of the Master Administrative Screen and the next checked-in patient for Treatment is displayed. Upon identifying the patient in the waiting room, the tech selects his or her ID from the Dropdown list of Techs (to update the field). The Modality (if applicable) is verified and updated if necessary. Pressing YES updates the patient tracking record with the new information, and moves the patient to in-process status in the tracking application. The patient name is removed from the Patient Arrival Board, and the patient status is changed to “in treatment” in the system. Selecting NO returns the receptionist to the Master Administrative Screen. In multiple modality departments, and for some instances where the next sequential patient may not be ready or available for treatment, the Select Next Patient from List button is used to select the next patient from the list of available patients. The receptionist or tech presses the PATIENT FROM LIST button on the Treatment side of the Master Administrative Screen which displays a selection list of all “Checked-in” patients for the registrar to choose from. Highlighting the patient moves the patient down to the confirmation area where Modality Queue is displayed for that patient. Upon identifying the desired patient in the waiting room, the tech selects his or her ID from the Dropdown list of Techs (to update the field). The Modality (if applicable) is verified and updated if necessary. Pressing YES updates the patient tracking record with the new information, and moves the patient to in-process status in the tracking application. The patient name is removed from the Patient Arrival Board, and the patient status is changed to “in process” in the system. Selecting NO returns the receptionist to the Master Administrative Screen. Once patient treatment is complete, the receptionist or tech presses the PATIENT DONE button on the Treatment side of the Master Administrative Screen which displays a selection list of all “in-process” patients for the registrar to choose from. Highlighting the patient moves the patient down to the confirmation area where Modality Queue is displayed for that patient. Upon identifying the desired patient to complete treatment, the tech confirms his or her ID from the Dropdown list of Techs and updates the field as necessary. The Modality (if applicable) is verified and updated if necessary and a Comment Code is selected from the dropdown list of available codes if necessary. Pressing YES displays the Send To Department Screen. Selecting the next treatment department on this screen sends notification to the receiving department that the patient is on his way for treatment and sets the patient to “in transit” status on their master screen. Since the relationship between departments and modalities has been established and maintained in the Queue Table, the user is presented only with the associated treatment departments to select from. If there is a treatment department which does not allow subsequent routing, the screen shows the message on the right. If DONE is selected, the patient is marked as complete for the patient's treatment event, and no forwarding notification records are created. Selecting CANCEL from the Send To Department Screen returns the Receptionist to the Master Administrative Screen and the patient record remains in “in-process” status. Selecting the MANAGEMENT TRACKING SCREEN button on the Display Queue Screens side of the Master Administrative Screen results in the display shown in FIG. 21 . This screen functions the same in both Registration and Ancillary Treatment Department Modes, and displays all of the patients in that specific queue for the day and their status or disposition from the check-in queue. This Screen is similar to the QueueView™ (Incoming Calls Management Institute, Annapolis, Md.) screen that is available to registrars and treatment department staff to view patient activities and to complete (DONE) patients in the system remotely. Additional functionality is provided in the Master Administrative Screen to allow the user to view and “UNDO” entries performed in error. For example, an incorrect patient is selected and processed as DONE in error. The UNDO button can reverse the last timestamp for that patient (as explained below). The Management Status Screen displays the list of all patients and their status within the Registration or Treatment Departments. The Modality and (Next) Clinical Department columns are populated as appropriate for the department or registration area. Patients that have been checked-in but not processed for a specified elapsed time are indicated with a YELLOW status color based on a setting in the workstations “.ini” file that has determined according to a pre-determined user defined business rule. If that patient wait time exceeds a maximum wait time, the status color changes to RED and an e-mail notification is sent to a supervisor for resolution and follow-up based on a setting in the workstations “.ini” file that has determined according to a pre-determined user defined business rule. Highlighting a patient and pressing the UNDO LAST TIME FOR SELECTED PATIENT removes the most recent timestamp from the patient record. The Patient record is re-set to the previous status. A warning window appears asking “Are you SURE you want to change the Patient Status?” Selecting YES completes this transaction. Selecting NO returns the user to the Master Administrative Screen. Repeating this process removes the status of the record completely provided the patient has not been forwarded to, and checked-in by, the “sent to” department. All Undo activities are preferably logged to an audit table for review incase of errors or discrepancies. Selecting PUBLIC TRACKING SCREEN from the Master Administrative Screen results in a display that appears on the Patient Arrival display. The information is publicly viewable in the Registration and Treatment Department waiting areas. Selecting PUBLIC TRACKING SCREEN from the Display Queue screens section of the Master Administrative Screen displays the Patient Arrival Board ( FIG. 22 ) on the display board (which is preferably large) in the waiting area. Selecting SHUTDOWN PUBLIC SCREEN from the Master Administrative Screen shuts down the Patient Arrival Tracking board. A warning window appears asking “Are you SURE you want to shutdown the PUBLIC Tracking Screen?” EXAMPLE 4 Use of QueueView™ The QueueView™ Application is an application that resides on any PC as a “remote” view of the Management Status Screen for the selected department or Modality. This application may also reside in a Citrix environment. QueueView™ has been designed to provide an Inquiry function to provide a detailed view of patient tracking information as well as a Process function to enable specific patients to have a completed status of “Done.” This capability is controlled via a setting in the workstation's “.ini” file. QueueView™ is deployed in two configurations: a) Administrative view—for supervisors to monitor activity with no ability to change or alter patient tracking information; and b) Registration/Clinical Department View—providing the user with the ability to view patient activity for the specified department or queue with additional functionality to allow these staff to complete (DONE) a patient from their work area. Status notifications are processed in QueueView™ the same as for the Management Status Screen in the Master Administrative Screens. The Administrative View screen ( FIG. 23A ) allows the supervisor or department head to view activity in the system without going to the reception desk to view the Management Status Screen. The Registration/Clinical Department View screen ( FIG. 23B ) allows the registrars, department clinicians, and techs to view activity for their department or modality remotely in their work areas to monitor patients that are waiting to be processed. The DONE button on this screen functions the same as the Registration or Ancillary Treatment DONE buttons, depending on where the application is used. The Maintenance Application Functions screen ( FIG. 24 ) is for loading the Daily hospital scheduling system file, archiving Daily Activity to the History File and generating the Signature report file, loading Identification Card (e.g., Loyalty Card) Information, Reference Table Upkeep, Department and Modality Queue Maintenance, Routing Maintenance, and Registrar and Comment Maintenance. These functions are not for use by the general user population but are used to maintain certain components of the application environment and to load reference data and tables. To import the Daily Schedule information for the next business day, enter the path and file name for the schedule to be imported if it does not automatically populate the Import File Name and Press Import New Schedule. A display indicates the number of scheduled records loaded. To Archive the daily activity and Electronic Signatures at the end of the day, press the Archive button. The Archival Signature report for all departments and queues is generated and saved to the Database Server. All Daily Transactions are moved to the Patient Activity History table for reference and reporting availability. To Import/Update Loyalty Card information, enter the path and file name for the Loyalty Card load file (.CSV format) and press the Import/Update Button. A display indicates the number of records processed. The Queue Table Maintenance Screen ( FIG. 25A ) is used to add and de-activate department and modality queues within the Patient Tracking Application. Queues can be either department queues or modality queues depending on whether a parent queue is indicated in the Parent column. This is used for aggregating modalities within a department for screen displays and reporting. Field Descriptions include: a) Name/Code*—the Queue Identifier which is displayed in all selection screens (this is also the entry that is used in the PatientArrivalTracking.ini file to configure the application to point to the appropriate queue or department); b) Long Name—descriptive name for the queue; c) Department—an optional field; d) Notes—memo area where specific information can be noted for a specific queue; e) Status*—indicates whether the queue is active or inactive (once a queue has been applied to a tracking record it can not be deleted, but can get marked as inactive to prevent further use); and f) Parent (where “child” modalities are assigned to “parent” departments). An asterisk (*) indicates required fields to update and add Department and Modality Queues to the database and application. To allow for hierarchical processing and future reporting, the Parent column is used to aggregate modalities to higher level departments The Registrar Initials table on the Registrar Maintenance screen ( FIG. 25B ) defines personnel to the application for assigning them to patient process activities and audit trail functions. These Personnel identifiers are specific to a particular department. If a resource works in multiple departments or areas, they will need to be entered in multiple times. The Comment Codes table defines the standardized comments that are used to add notations to patient records for reference and analytical purposes. These comments are Department or Modality specific. The Registrar Initials maintenance screen ( FIG. 25B ) is used to enter Registrar, Tech, and Receptionist initials and identifying information into the application for the ID functions on the Patient selection and Done functions (these ID's are Department Queue Specific). The Comment Code maintenance section of the Registrar Maintenance screen ( FIG. 25B ) is used to enter Comments and comment codes for the Done Screens throughout the application (these codes are preferably Department Queue specific). The Routing Maintenance Table screen ( FIG. 26 ) is where the application maps target departments to source departments. This allows the user to define where one department can send patients upon completion (DONE Process) within that department. Mappings made in this table populate the “Send To” screen at the completion of a patient treatment event within a department. This table maintenance screen maintains the routing relationships for each department within the application for the SEND TO screen functions at the end of the DONE process. The “To Queue” field identifies the “target” queue for the send to function, and can be populated with any queue entered in Queue Maintenance. The “From Queue” field identifies the “source” queue that is sending the patient, and can be any queue that is identified in Queue Maintenance. A queue can send a patient to itself—re-routing a patient through the radiology department for a second modality treatment. The to and from relationships are meaningful and relevant so as not to populate the selection screen with incorrect or inaccurate information. The system includes a Wait Time Export Function which provides an export of the patient tracking data into a format (e.g., comma delimited) suitable for use in a software program such as Microsoft Excel. This function allows for the export of the current day's data or data from one or more days of history. Clicking on the desktop icon labeled “Wait Time Export” results in the display of the screen shown in FIG. 27A . The screen displayed defaults to select data from ‘Today.’ Clicking on ‘History’ presents the screen shown in FIG. 27B . If an export of historical data is required, then the user clicks on ‘History’ and populate the ‘Export From Date’ and ‘Export To Date’ fields or retains the default selection of ‘Today.’ Clicking on the Folder Icon selects the filename and destination for the resulting export file. A dialog box: ‘Save As’ is displayed. Once the export function is complete, the screen shown in FIG. 28 is displayed for either current day or historical data. Close the ‘Wait Time Export’ dialog box by pressing the ‘X’ in the upper right hand corner of the display. There is an Icon on the desktop labeled ‘Wait Time’ which is the resulting CSV (Comma Separated Value) file created from the export function. Double clicking on this icon opens the file with Microsoft Excel if installed on the workstation. EXAMPLE 5 GlobalView™ Dashboard The GlobalView™ Dashboard inquiry function provides Administration and Customer Service with the ability to view in real time Patient Tracking activity for all Registration and Treatment Department Queues in which the Patient Tracking Application has been deployed. Double clicking on the ‘Patient Tracking GlobalView’ icon on the Windows desktop results in the display shown in FIG. 29A . An ‘Overall Status’ section describes cumulative information for all areas showing: on the meter the total number of patients waiting to be “serviced” (either registration or treatment); the current number of patients “in process” in the odometer gauge; and the total completed patients is displayed in its identified counter box. Adjacent sections represent each of the registration/treatment areas that the Patient Tracking Application has been deployed to throughout the facility. If the number of departments exceeds the screen limitations, a scroll bar displays so that one may scroll to view all departments. Each area depicts at a glance the summary status of patients in a respective Registration or Ancillary Department. Depending on the refresh rate that has been user-defined on this particular workstation, this display and the underlying statistical information is refreshed so as to reflect current data from the facility in real time. Each section is also preferably a mouse clickable button. Selecting any of these sections highlights that section identifying it for further inquiry activity, which is evidenced by the green light illuminating as shown in FIG. 29B . Positioning the cursor over the ‘Expand (Show Statistics)’ area located near the lower right side of the display and subsequently clicking on the bar results in the display expanding and revealing statistics for that particular area associated with the illuminated green light as shown in FIG. 30 . Two tabs are displayed for the illuminated sections that are expanded: Stats and Patients. The Stats tab provides a variety of computed statistical data for the selected area. This tab is grouped into three categories: Times, Counts, Stats by Technician. The “Times” Area includes these times as defined: a) Transit Time—(Swipe to Check-In), b) Wait Time—(Check-In to In-Process), and c) Procedure Time—(In-Process to Complete). Computations are performed to display the average, longest, shortest and current times for each category noted above. The “Counts” Area includes a display of the current number or count of Patients Checked-in to that area (Overall, Department or Ancillary depending on initial selection), the number of In-process patients, and the number of Completed patients. The “Stats by Technician” Area includes a scrollable window that contains the name of the registrar or technician for the area displayed along with the number of patients processed and the average process time for that individual registrar or technician. These statistics are updated on a regular basis using real-time data at the interval specified for that workstation. The Patients tab ( FIG. 31 ) displays the detailed patient data in an inquiry only format similar (if not identical) to that displayed by the QueueView™ application described above. Patients that have been waiting for a period of time that falls within the predefined criteria according to the user-defined business rules display in the color corresponding to that business rule. There are certain areas that can be selected that have a set of departments reporting up to them. Selecting one of these shows the resultant displays reflecting statistical data that is relevant to that particular area. In the screen shown in FIG. 32A , a Registration area or queue has been selected. In FIG. 32B , the ‘Expand (Show Statistics)’ with the ‘Stats’ tab has been selected. In FIG. 33A , the ‘Expand (Show Statistics)’ with the “Patients” tab has been selected for the same Registration area or queue. If the area selected is an Ancillary area that has been built with Modalities associated with the area or queue then a new window opens as a result leaving the original display on the screen shown in FIG. 33B . In the example above, ‘Radiology’ was highlighted and then selected with the resultant new window being opened that included all of the modalities associated with the Radiology queue being placed on the desktop directly beneath the original display. As is the case with the Registration area or queue displays, the modality displays also permit the selection of the statistical or patient detail tabs that contain data relevant to the area or in this case, modality selected. Displays of both statistical and patient tabs are shown in FIGS. 34A and 34B . The system provides constant detail monitoring. By placing the cursor over the ‘Stats’ tab, clicking and holding the left mouse button and dragging, the entire window can be undocked and placed in a convenient location on the Windows desktop space. Similarly, this function can be performed for the ‘Patients’ tab as well as shown in FIGS. 35A and 35B . The ability to define the placement of these windows away from the primary window provides the User with the capability to open multiple windows and thus gain visibility into multiple patient registration and ancillary areas and monitor statistics related to these areas on a real time basis as shown in FIGS. 36A and 36B . EXAMPLE 6 System Advertising Module A System Advertising Module provides for advertising, which is facilitated by hardware and software components of the system of the invention. This advertising can take place on a large screen (located in waiting areas). Along with the status of the patient, some portion of the screen is utilized to provide the following examples of information: news, weather, registration requests and advertisements. This information is displayed in configurable, time-based increments on any of the system output devices. This advertising can also take place on a kiosk such that advertising messages are displayed in short bursts on the kiosk screen during the patient's usage of the kiosk. This advertising can also take place on printed material (e.g., any printed material which is provided by the system may contain advertising material). This advertising is beneficial to the advertiser in several ways. The Advertising talks directly to a specific audience. The system of the invention collects data regarding the profile of the institution's traffic. This profile information is a valuable tool in aiming advertising campaigns directly at a target audience. Specific patient traffic is perceived by the advertiser as: specific target viewer ship, ability to create direct product and brand awareness to this specific target audience, creation of product and brand influence and in some cases, the patient asking the clinician for a specific product. Also, advertising via the system of the invention provides the “Last Point of Communication” directly to a possible product user prior to that individual's meeting with a clinician. This advertising allows the product brand to “Own the Environment.” This advertising specifically addresses all three of the advertiser's desires regarding exposure. These desires are for exposure: prior to diagnosis, after diagnosis, but prior to treatment, and regarding persistency of treatment. This is highly sought after in that it will turn a drug into the compliant mean of treating a medical condition. This Advertising Module can provide direct financial value to the healthcare institution in several ways. The institution can develop a pricing model and invoice the advertiser for this service. This invoicing may occur via the profile and traffic that actually exposes to the components of this advertising. The advertiser pays for what they actually receive. The advertiser may decide to provide the system of the invention for an institution gratis. In return, the advertiser receives some amount of advertising on the system components. Other Embodiments This description has been by way of example of how the devices, processes and methods of the invention can be made and carried out. Various details may be modified in arriving at the other detailed embodiments, and many of these embodiments will come within the scope of the invention. Therefore, to apprise the public of the scope of the invention and the embodiments covered by the invention, the following claims are made.

A system for making the process of registering at and receiving treatment in a healthcare facility more efficient and safe has been developed. The system utilizes computer communications network-based systems, software, various input and output stations, and a patient identification card (e.g., Loyalty Card) that work together to allow (a) providers to direct, track, and optimize the efficiency of patient activity and (b) patients to have ready access to their status and, in some cases, control of the healthcare process.

BACKGROUND OF THE INVENTION 1. Field of the Invention The instant disclosure relates to a bidirectional wireless charging device; in particular, to a bidirectional wireless charging device with an integrated transceiver chip. 2. Description of Related Art With the technology well developed, there are many kinds of personal mobile devices and wearable devices which connect with the Internet, provide people a so-called mobile life, and thus increase the convenience in our daily lives. However, the requirement of electric power for using these electric products also gradually increases. For solving this problem, there is a wireless charging device developed currently. The wireless charging device can be generally categorized as two kinds, wherein one is the wireless charging device using the Electromagnetic Induction Technology and another is the wireless charging device using the Electromagnetic Resonance Technology. Particularly, the wireless charging device using the Electromagnetic Induction Technology is more common. The advantage of the wireless charging device is that the electric device and the wireless charging device do not need wires to have a connection. In the prior art, one wireless charging device merely has a signal direction wireless charging function. For example, the wireless charging device as a powering end can merely provide electric power, and the wireless charging device as a charging end can merely receive electric power. Generally, there is not the wireless charging device which can provide electric power outdoors, which means that the user's portable electric device may not be used anywhere anytime. For example, when the power of the wireless charging device runs out and the wearable device, such as a smart watch, has an urgent request for charging, if there was an electric device having sufficient power which could charge the smart watch, the above problem could be solved. Therefore, in the prior art, there has been a kind of bidirectional wireless charging device developed. The bidirectional wireless charging device has a power providing function and a power receiving function. Thus, the bidirectional wireless charging device can be a powering end or a charging end under different circumstances. However, the traditional bidirectional wireless charging device must have an emitter chip and its corresponding circuit (such as a control circuit, a modulation circuit, a power stage circuit and the like), and have a transceiver chip and its corresponding circuit (such as a control circuit, a modulation circuit, a power stage circuit, a rectifying circuit and the like). In other words, to realize the bidirectional wireless charging function, the area of inner circuit of the bidirectional wireless charging and the cost dramatically increase. SUMMARY OF THE INVENTION The instant disclosure provides a bidirectional wireless charging device. The bidirectional wireless charging device comprises a transceiver chip receiving a switch signal. The transceiver chip comprises a power stage circuit and a control module. The power stage circuit is electrically connected to a coil, and outputs a voltage to the coil or receives an induced voltage from the coil. The control module is electrically connected to the power stage circuit, and correspondingly makes the transceiver chip turn into a power mode or a charging mode according to the switch signal. The transceiver chip provides the voltage to the coil when the switch signal indicates that the transceiver chip turns into the power mode. The transceiver chip receives the induced voltage from the coil and charges a power storage unit of the bidirectional wireless charging device, when the switch signal indicates that the transceiver chip turns into the charging mode. The instant disclosure further provides a bidirectional wireless charging system. The bidirectional wireless charging system comprises at least two bidirectional wireless charging devices. Each bidirectional wireless charging device comprises a transceiver chip receiving a switch signal. The transceiver chip comprises a first bidirectional wireless charging device and a second bidirectional wireless charging device. The first bidirectional wireless charging device and the second bidirectional wireless charging device respectively comprise a power stage circuit and a control module. The power stage circuit is electrically connected to a coil, and outputs a voltage to the coil or receives an induced voltage from the coil. The control module is electrically connected to the power stage circuit, and correspondingly makes the transceiver chip turn into a power mode or a charging mode according to the switch signal. The first bidirectional wireless charging device and the second bidirectional wireless charging device are either a charging end and a powering end according to the switch signal. When the first bidirectional wireless charging device is the powering end, the transceiver chip of the first bidirectional wireless charging device turns into the power mode and provides the voltage to the coil so as to make the first bidirectional wireless charging device provide a pulse width modulated signal to the second bidirectional wireless charging device. The pulse width modulated signal includes an electromagnetic energy. When the second bidirectional wireless charging device is the charging end, the transceiver chip of the second bidirectional wireless charging device turns into the charging mode, receives the induced voltage from the coil, and charges a power storage unit of the second bidirectional wireless charging device. To sum up, the bidirectional wireless charging device provided by the instant disclosure can used as a powering end or a charging end to improve the convenience of the bidirectional wireless charging device. Moreover, compared with the traditional bidirectional wireless charging device, the transceiver chip of the bidirectional wireless charging device provided by the instant disclosure integrates the power mode operation module and the charging mode operation module into a single chip. Thereby, merely one control module and one power stage circuit are needed for the instant disclosure to provide the bidirectional wireless charging function, which effectively shrinks the circuit area, decreases the cost and also reduces the system complexity. For further understanding of the instant disclosure, reference is made to the following detailed description illustrating the embodiments and examples of the instant disclosure. The description is only for illustrating the instant disclosure, not for limiting the scope of the claim. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which: FIG. 1 shows a schematic diagram of a bidirectional wireless charging system of one embodiment of the instant disclosure; FIG. 2 shows a block diagram of a bidirectional wireless charging device of one embodiment of the instant disclosure; FIG. 3A a schematic diagram of a bidirectional wireless charging device of one embodiment of the instant disclosure; FIG. 3B a schematic diagram of a bidirectional wireless charging device of another embodiment of the instant disclosure; FIG. 4 shows a schematic diagram of a bidirectional wireless charging device of one embodiment of the instant disclosure in the power mode; FIG. 5 shows a schematic diagram of a bidirectional wireless charging device of one embodiment of the instant disclosure in the charging mode; FIG. 6 shows a flow chart of a bidirectional wireless charging device of one embodiment of the instant disclosure in the power mode; and FIG. 7 shows a flow chart of a bidirectional wireless charging device of one embodiment of the instant disclosure in the charging mode. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The aforementioned illustrations and following detailed descriptions are exemplary for the purpose of further explaining the scope of the instant disclosure. Other objectives and advantages related to the instant disclosure will be illustrated in the subsequent descriptions and appended drawings. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. It will be understood that, although the terms first, second, third, and the like, may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only to distinguish one element, component, region, layer or section from another region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the instant disclosure. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Please refer to FIG. 1 , FIG. 1 shows a schematic diagram of a bidirectional wireless charging system of one embodiment of the instant disclosure. The bidirectional wireless charging system comprises at least two bidirectional wireless charging devices. In this embodiment, the bidirectional wireless charging system comprises a first bidirectional wireless charging device 1 A, a second bidirectional wireless charging device 1 B and a third bidirectional wireless charging device 1 C. It is to be noted that FIG. 1 is merely used to describe the bidirectional wireless charging system of one embodiment of the instant disclosure but does not limit the instant disclosure. In other embodiments, the bidirectional wireless charging system can merely comprise two bidirectional wireless charging devices or comprise more than two bidirectional wireless charging devices. The first bidirectional wireless charging device 1 A, the second bidirectional wireless charging device 1 B and the third bidirectional wireless charging device 1 C can be a mobile phone, a tablet computer, a laptop, a wireless charger, a smart watch, a set-top box or other electric products having a wireless charging function. For an easy instruction and understanding of the instant disclosure, in the following description, the first bidirectional wireless charging device 1 A may be a mobile phone, the second bidirectional wireless charging device 1 B may be a wireless charger and the third bidirectional wireless charging device 1 C may be a smart watch. In addition, the first bidirectional wireless charging device 1 A, the second bidirectional wireless charging device 1 B and the third bidirectional wireless charging device 1 C are operated according to the Electromagnetic Induction Technology. However, it is not limited herein. The first bidirectional wireless charging device 1 A, the second bidirectional wireless charging device 1 B and the third bidirectional wireless charging device 1 C can also be operated according to the Electromagnetic Resonance Technology. The second bidirectional wireless charging device 1 B may often be provided with commercial power and thus maintain sufficient power. When the first bidirectional wireless charging device 1 A has insufficient power, the user can operate the first bidirectional wireless charging device 1 A to send a switch signal to the second bidirectional wireless charging device 1 B. For example, the switch signal is an analogue signal indicating that the bidirectional wireless charging device turns into a power mode or a charging mode. For instance, the bidirectional wireless charging device receiving a high-level switch signal would turn into the power mode, and he bidirectional wireless charging device receiving a low-level switch signal would turn into the charging mode. After receiving the high-level switch signal, the second bidirectional wireless charging device 1 B turns into the power mode and starts to charge the first bidirectional wireless charging device 1 A. In another case, when the stored power of the first bidirectional wireless charging device 1 A is insufficient to drive the first bidirectional wireless charging device 1 A, the user can also operate the second bidirectional wireless charging device 1 B to send a low-level switch signal to the first bidirectional wireless charging device 1 A. The switch signal has energy, so the first bidirectional wireless charging device 1 A can be turned on by the energy of the switch signal. After that, the first bidirectional wireless charging device 1 A would reply the second bidirectional wireless charging device 1 B with a high-level switch signal. After receiving the high-level switch signal, the second bidirectional wireless charging device 1 B starts to charge the first bidirectional wireless charging device 1 A. When the stored power of the first bidirectional wireless charging device 1 A reaches a predetermined value (such as 90% of the maximum stored power of the first bidirectional wireless charging device 1 A), the first bidirectional wireless charging device 1 A sends a status signal to the second bidirectional wireless charging device 1 B, so that the second bidirectional wireless charging device 1 B ends the power mode and thus stops charging the first bidirectional wireless charging device 1 A. Sometimes the user may bring the first bidirectional wireless charging device 1 A, the second bidirectional wireless charging device 1 B and the third bidirectional wireless charging device 1 C outside, and in this case the second bidirectional wireless charging device 1 B can't be provided with commercial power and can't maintain sufficient power. When the second bidirectional wireless charging device 1 B has insufficient power, the second bidirectional wireless charging device 1 B can't charge the third bidirectional wireless charging device 1 C. There may be a more urgent demand for using the third bidirectional wireless charging device 1 C, so the user would try not to run out the power of the third bidirectional wireless charging device 1 C. At this moment, the user can operate the third bidirectional wireless charging device 1 C to send a switch signal to the first bidirectional wireless charging device 1 A, so that the first bidirectional wireless charging device 1 A would turn into the power mode and start to charge the third bidirectional wireless charging device 1 C. In other words, the first bidirectional wireless charging device 1 A, the second bidirectional wireless charging device 1 B and the third bidirectional wireless charging device 1 C provided in this embodiment can be used as a charging end or a powering end, so as to increase the convenience of the bidirectional wireless charging system. In addition, the switch signal can be a Pulse Width Modulation signal (PWM signal) sent by a coil; however, it is not limited herein. For example, in other embodiments, the bidirectional wireless charging device 1 can send a switch signal wirelessly via a wireless transmission unit (not shown in FIG. 1 ). There is further instruction for a structure of the bidirectional wireless charging device in the following description. Please refer to FIG. 2 , FIG. 2 shows a block diagram of a bidirectional wireless charging device of one embodiment of the instant disclosure. The bidirectional wireless charging device 1 can be one of the above mentioned first bidirectional wireless charging device, second bidirectional wireless charging device 1 B and third bidirectional wireless charging device 1 C. For a need to instruct easily, they are described as the bidirectional wireless charging device 1 in the following description. The bidirectional wireless charging device 1 comprises a transceiver chip 10 , a coil 11 , a power processing unit 12 and a power storage unit 13 . The coil 11 is electrically connected to the transceiver chip 10 . The transceiver chip is electrically connected to the power processing unit 12 and the power storage unit 13 . The power processing unit 12 is electrically connected to the power storage unit 13 . The coil 11 can be a cable coil or other inductor that can generate an induced voltage corresponding to a variable electromagnetic field. When the bidirectional wireless charging device 1 is used as a powering end, the coil 11 can convert the voltage into a PWM signal and send the PWM signal out. The PWM signal includes an electromagnetic energy, so a charging end can charge with the received electromagnetic energy. When the bidirectional wireless charging device is used as a charging end, the coil 11 can sense the PWM signal and convert the electromagnetic energy of the PWM signal into an induced voltage. The transceiver chip 10 receives the switch signal and correspondingly controls and makes the bidirectional wireless charging device 1 turn into the power mode or the charging mode. Moreover, when the bidirectional wireless charging device 1 is used as a powering end, the transceiver chip 10 receives the voltage from the power processing unit 12 and the power storage unit 13 , and provides the voltage to the coil 11 so that the coil 11 generates a PWM signal. When the bidirectional wireless charging device 1 is used as a charging end, the transceiver chip 10 receives an induced voltage generated by the coil 11 , and rectifies and regulates the induced voltage to generate a regulated voltage. The power processing unit 12 manages the stored power of the bidirectional wireless charging device 1 . For example, the power processing unit 12 determines when to transmit the regulated voltage outputted by the transceiver chip 10 to the power storage unit 13 , or makes the power storage unit 13 provide power to the transceiver chip 11 . The power storage unit 13 is used to store power, for example, the battery of the bidirectional wireless charging device 1 or other power storage devices, such as a capacitor. For further instruction, please refer to FIG. 3A . FIG. 3A is a schematic diagram of a bidirectional wireless charging device of one embodiment of the instant disclosure. As described in the above embodiment, the bidirectional wireless charging device 1 comprises a transceiver chip 10 , a coil 11 , a power processing unit 12 and a power storage unit 13 . The relationship of connection between the transceiver chip 10 , the coil 11 , the power processing unit 12 and the power storage unit 13 for this embodiment can be referred to the description in the previous embodiment, and thus the redundant information is not repeated. The following description is merely for the difference between this embodiment and the previous embodiment. The transceiver chip 10 further comprises a control module 101 , a power stage circuit 102 , a charging mode operation module 104 and a power mode operation module 103 . The control module 101 is electrically connected to the power stage circuit 102 . The power stage circuit 102 is electrically connected to the coil 11 . The charging mode operation module 104 is electrically connected to the control module 101 and the coil 11 . The power mode operation module 103 is electrically connected to the control module 101 and the coil 11 . In conjunction with FIG. 3 a and FIG. 3B , FIG. 3B is a schematic diagram of a bidirectional wireless charging device of another embodiment of the instant disclosure. The transceiver chip 10 of the bidirectional wireless charging device 1 also comprises a control module 101 , a power stage circuit 102 , a charging mode operation module 104 and a power mode operation module 103 . The following is further instruction about the structure and function of the transceiver chip 10 . The control module 101 comprises a control unit 1010 . The control unit 1010 is electrically connected to the power stage circuit 102 . The control unit 1010 controls and adjusts the voltage output by the power stage circuit 102 . The power stage circuit 102 comprises a power switch, a pulse width modulation circuit, an isolated high-frequency transformer, a rectifying circuit and an output filter (not shown in FIG. 3B ). The rectifying circuit can be, for example, a half-bridge rectifying circuit or a full-bridge rectifying circuit, to generate a rectified voltage. When the bidirectional wireless charging device 1 is used as a power end, the power stage circuit 102 drives the power switch and provides a voltage to the coil 11 , so that the coil 11 is driven to have a resonance and output a PWM signal. When the bidirectional wireless charging device 1 is used as a charging end, the power stage circuit 102 receives an induced voltage from the coil 11 and generates a rectified voltage. The detailed structure and the working mechanism of the power stage circuit 102 would be able to be comprehended by one skilled in the art and further descriptions are therefore omitted. The power mode operation module 103 comprises a demodulation unit 1030 electrically connected to the control unit 1010 and the coil 11 . The demodulation unit 1030 receives a PWM signal PWM′ output by another bidirectional wireless charging device which is used as a charging end via the coil 11 , and demodulates the received PWM signal PWM′. The PWM signal PWM′ includes a status message sent from the charging end. In detail, the status message comprises a quantity of the charging end (for example, the currently stored electric quantity of the charging end), an energy adjusting request, an energy maintaining request, a cut-off supply request or the like. The demodulation unit 1030 filters the high-frequency band out from PWM signal PWM′, maintains the amplitude, and uses the amplitude size as a status message sent by the charging end. After that, the demodulation unit 1030 outputs the demodulated status message to the control unit 1010 , so that the control unit 1010 correspondingly controls the voltage output by the power stage circuit 102 according to the demodulated status message. For example, when the status message includes an energy adjusting request, the control unit 1010 would correspondingly adjust the voltage output by the power stage circuit 102 according to the currently stored power of the charging end. When the status message includes an energy maintaining request, the control unit 1010 would make the power stage circuit 102 maintain the provided voltage. The charging mode operation module 104 comprises a voltage regulating unit 1040 and a modulation unit 1041 . The voltage regulating unit 1040 is electrically connected to the control unit 1010 , the power stage circuit 102 and the power processing unit 12 . The modulation unit 1041 is electrically connected to the control unit 1010 and the coil 11 . The voltage regulating unit 1040 receives the rectified voltage output by the power stage circuit 102 , regulates the rectified voltage and outputs the regulated voltage to charge the power storage unit 13 of the bidirectional wireless charging device 1 . The modulation unit 1041 is controlled by the control unit 1010 . The control unit 1010 controls and makes the modulation unit 1041 generate a PWM signal including a status message according to the regulated voltage value and the power currently stored in the bidirectional wireless charging device. Please refer to FIG. 4 . FIG. 4 shows a schematic diagram of a bidirectional wireless charging device of one embodiment of the instant disclosure in the power mode. When another bidirectional wireless charging device 1 ′ (not shown in FIG. 4 , such as the wireless charging device 1 ′ in FIG. 5 ) has insufficient power (for example, the left power of the bidirectional wireless charging device 1 ′ is less than 20% of the maximum stored power but more than the minimum stored power), the user can operate the bidirectional wireless charging device 1 ′ to send a switch signal, such as a high-level switch signal. After receiving the switch signal, the bidirectional wireless charging device 1 turns into the power mode and becomes a powering end to start to provide power to the bidirectional wireless charging device V. In addition, in this embodiment, the high-level switch signal corresponds to the power mode but it is not limited herein. That is, in other embodiments, the low-level switch signal can also be set to correspond to the power mode. Further, when the switching unit (not shown in FIG. 4 ) of the control module 101 receives the high-level switch signal, the switching unit makes the circuit path corresponding to the power mode operation module 103 turn on (shown as the circuit path connected by the real line in FIG. 4 ), and makes the circuit path corresponding to the charging mode operation module 103 turn off (shown as the circuit path connected by the dash line in FIG. 4 .). The switching unit may be, for example, a multiplexer or a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) switch, so as to switch the corresponding circuit path according to the switch signal. After the bidirectional wireless charging device 1 turns into the power mode, the power processing unit 12 controls the power storage unit 13 to provide power to the power stage circuit 102 . After that, the control unit 1010 of the control module 101 controls the power stage circuit 102 to output a voltage to the coil 11 so as to drive the coil to have the resonance and to output a PWM signal having the electromagnetic energy. As the charging end, the coil 11 of the bidirectional wireless charging device 1 ′ generates an induced voltage via the electromagnetic induction and start to charge. When the stored power of the bidirectional wireless charging device 1 ′ reaches a predetermined value, the bidirectional wireless charging device 1 ′ would output a PWM signal including a cut-off supply request. After the demodulation unit 1030 of the power mode operation module 103 of the bidirectional wireless charging device 1 receives a PWM signal PWM′ via the coil 11 , it would demodulate the PWM signal PWM′ and output a demodulated status message. The control unit 1010 receives the status message and correspondingly controls the output power of the power stage circuit 102 according to the status message. For example, when the bidirectional wireless charging device 1 receives the status message indicating that the stored power of the bidirectional wireless charging device 1 ′ reaches a predetermined value (such as 90% of the maximum stored power of the bidirectional wireless charging device 1 ′, but it is not limited herein), the control unit 1010 of the bidirectional wireless charging device 1 makes the power stage circuit 102 stop charging the bidirectional wireless charging device 1 ′. Please refer to FIG. 5 . FIG. 5 shows a schematic diagram of a bidirectional wireless charging device of one embodiment of the instant disclosure in the charging mode. Different from the embodiment shown in FIG. 4 , the bidirectional wireless charging device 1 ′ shown in FIG. 5 is used as the charging end. In addition, the bidirectional wireless charging device 1 shown in FIG. 4 and the bidirectional wireless charging device 1 ′ shown in FIG. 5 have the same structure but different operation modes. Further, when the user tends to charge the bidirectional wireless charging device 1 ′, the user can make the bidirectional wireless charging device 1 ′ turn into the charging mode. At this moment, the switching signal generating unit (not shown in FIG. 5 ) of the bidirectional wireless charging device 1 ′ would generate a high-level switch signal and a low-level switch signal. The high-level switch signal is sent to the bidirectional wireless charging device 1 (not shown in FIG. 5 , such as the wireless charging device 1 ), so that the bidirectional wireless charging device 1 turns into the power mode. The low-level switch signal is sent to the control module 101 ′ of the bidirectional wireless charging device 1 ′, so that the bidirectional wireless charging device 1 ′ turns into the power mode. After the switching unit (not shown in FIG. 5 ) of the control module 101 ′ receives the switch signal, the switching unit makes the circuit corresponding to the charging mode operation module 104 ′ turn on (shown as the circuit path connected by the real line in FIG. 5 ), but makes the circuit corresponding to the powering mode operation module 103 ′ turn off (shown as the circuit path connected by the dotted line in FIG. 5 ). As mentioned above, the switching unit, such as a multiplexer or a MOSFET switch, is configured to correspondingly switch the circuit paths according to the switch signal. The coil 11 ′ receives the PWM signal from the bidirectional wireless charging device 1 , and converts the electromagnetic energy of the PWM signal into an induced voltage. The power stage circuit receives and rectifies the induced voltage, and outputs a rectified voltage. The voltage regulating unit 1040 ′ of the charging mode operation module 104 ′ receives and regulates the rectified voltage, and generates a regulated voltage. After that, the voltage regulating unit 1040 ′ outputs the regulated voltage to the control unit 1010 ′, so as to provide power for the operation of the bidirectional wireless charging device V. Moreover, the voltage regulating unit 1040 ′ outputs the regulated voltage to the power processing unit 12 ′, and the power processing unit 12 ′ uses the regulated voltage to charge the power storage unit 13 ′. After receiving the regulated voltage, the control unit 1010 ′ makes the modulation unit 1041 ′ change the voltage amplitude of the coil 11 according to the regulated voltage value and the currently stored power of the bidirectional wireless charging device 1 ′, so that the coil 11 ′ generates a PWM signal PWM′ including a status message for informing the powering end about the current electric quantity of the bidirectional wireless charging device 1 ′, an energy adjusting request, an energy maintaining request or a cut-off supply request. The steps for the bidirectional wireless charging device 1 ′ to generate a PWM signal PWM′ are as follows. After receiving the regulated voltage, the control unit 1010 ′ determines whether the power provided from the power storage unit 13 ′ to the bidirectional wireless charging device 1 ′ is within a normal range. If the power provided by the power storage unit 13 ′ is not within the normal range, it means that the power currently stored in the power storage unit is insufficient to support and maintain the operation of the bidirectional wireless charging device V. At this moment, the control unit 1010 ′ makes the modulation unit 1041 ′ change the voltage amplitude of the coil 11 ′, so as to generate a PWM signal PWM′ including an energy adjusting request or an energy maintaining request. If the power provided by the power storage unit 13 ′ is within the normal range, the control unit 1010 ′ further detects whether the power stored in the power storage unit 13 ′ reaches a predetermined value. When the control unit 1010 ′ determines that the power stored in the power storage unit 13 ′ reaches the predetermined value, the control unit 1010 ′ makes the modulation unit 1041 ′ generate a PWM signal PWM′ including a cut-off supply signal. For example, when the power provided by the power storage unit 13 ′ is not within the normal range, the control unit 1010 ′ makes the modulation unit 1041 ′ generate a PWM signal PWM′ including an energy adjusting request, so as to request the powering end to provide a PWM signal PWM having more energy. When the power provided by the power storage unit 13 ′ is within the normal range and the power stored in the power storage unit 13 ′ has not reached the predetermined value (such as 90% of the maximum stored power of the bidirectional wireless charging device 1 ′), the control unit 1010 ′ makes the modulation unit 1041 ′ generate a PWM signal PWM′ including an energy adjusting request, so as to request the powering end to output a PWM signal PWM having more energy. In another case, the control unit 1010 ′ can also makes the modulation unit 1041 ′ generate a PWM signal PWM′ including an energy maintaining request, so as to make the powering end keep outputting the current PWM signal PWM. When the power provided by the power storage unit 13 ′ is within the normal range and the control unit 1010 ′ determines that the power stored in the power storage unit 13 ′ reaches the predetermined value, the control unit 1010 ′ makes the modulation unit 1041 ′ generate a PWM signal PWM′ including a cut-off supply signal, so as to make the powering end stop charging the bidirectional wireless charging device 1 ′. In addition, the above embodiment is an example for describing the application of the instant disclosure, but it is not limited herein. The user can set the normal range of power provided by the power storage unit 13 ′ and set the predetermined value of power stored in the power storage unit 13 ′ based on need. In other embodiments, the control unit 1010 ′ is also configured to make the modulation unit 1041 ′ generate a PWM signal PWM including a status message once every time interval, so as to inform the powering end of the current electric quantity of the bidirectional wireless charging device 1 ′, an energy adjusting request, or an energy maintaining request. Thereby, the powering end can dynamically adjust the electromagnetic energy provided to the bidirectional wireless charging device 1 ′. For instance, when the status message output by the bidirectional wireless charging device 1 ′ indicates that the currently stored power of the bidirectional wireless charging device 1 ′ is less than 70% of the maximum stored power, the powering end would output a PWM signal PWM with more energy. When the status message output by the bidirectional wireless charging device 1 ′ indicates that the currently stored power of the bidirectional wireless charging device 1 ′ is about 70%-90% of the maximum stored power, the powering end would output a PWM signal PWM with less energy. When the status message output by the bidirectional wireless charging device 1 ′ indicates that the currently stored power of the bidirectional wireless charging device 1 ′ is more than 90% of the maximum stored power, the powering end would stop charging the bidirectional wireless charging device 1 ′. In addition, the above embodiment is an example for describing the application of the instant disclosure, but it is not limited herein. The user can set how the bidirectional wireless charging device 1 and bidirectional wireless charging device 1 ′ dynamically adjust the electromagnetic energy based on needs. In this embodiment, the transceiver chip 10 of the bidirectional wireless charging device 1 merely comprises one power mode operation module 103 and one charging mode operation module 104 . In other embodiments, the transceiver chip 10 can also comprise a plurality of coils 11 , a plurality of power mode operation modules 103 and a plurality of charging mode operation modules 104 . The power mode operation modules 103 are electrically connected to the control module 101 and the corresponding coil 11 respectively, and the charging mode operation modules 104 are electrically connected to the control module 101 , the corresponding coils and the power stage circuit 102 respectively. Thereby, the bidirectional wireless charging device 1 can receive the electromagnetic energy from many powering ends at the same time or can provide the electromagnetic energy to many charging ends at the same time, which makes the bidirectional wireless charging device 1 have multiple bidirectional wireless charging functions. It is worth mentioning that, in the above embodiment, the user needs to manually operate the bidirectional wireless charging device 1 to generate a switch signal and start the charging process. However, in other embodiments, the two bidirectional wireless charging devices 1 and 1 ′ in the bidirectional wireless charging system can automatically start the charging process. In detail, in other embodiments, the user can set the bidirectional wireless charging devices 1 and 1 ′ to turn on the automatic charging function. When the distance between the bidirectional wireless charging devices 1 and 1 ′ is less than a preset distance, the bidirectional wireless charging devices 1 and 1 ′ would exchange their status messages to inform each other of the current electric quantity. When the current electric quantity of the bidirectional wireless charging device 1 is more than a first threshold value and the current electric quantity of the bidirectional wireless charging device 1 ′ is less than a second threshold value, the bidirectional wireless charging device 1 would start to charge the bidirectional wireless charging device 1 ′. For example, when the current electric quantity of the bidirectional wireless charging device 1 ′ is less than 20% of the maximum stored power and the current electric quantity of the bidirectional wireless charging device 1 is more than 80% of the maximum stored power, the bidirectional wireless charging device 1 would automatically charge the bidirectional wireless charging device V. In addition, the above embodiment is merely an example for describing the application of the instant disclosure, but it is not limited herein. The skilled in the art can set the predetermined distance, a first threshold value and second threshold value based on the actual operation and needs. Moreover, the user can also choose to turn off the automatic charging function of the bidirectional wireless charging devices 1 and 1 ′, and thus in the instant disclosure the bidirectional wireless charging devices 1 and 1 ′ can optionally turn on their automatic charging function. On the other hand, in other embodiments, the bidirectional wireless charging system can be set such that the bidirectional wireless charging device 1 periodically sends a switch signal to another bidirectional wireless charging device. When the bidirectional wireless charging device 1 ′ receives the switch signal and the bidirectional wireless charging device 1 ′ has insufficient power, the bidirectional wireless charging device 1 ′ would reply to this switch signal. After receiving the reply of the bidirectional wireless charging device 1 ′, the bidirectional wireless charging device 1 would turn into the power mode and start to charge the bidirectional wireless charging device 1 ′. In short, the bidirectional wireless charging device provided in the embodiment of the instant disclosure can be used as a powering end or a charging end, so as to increase the convenience of the bidirectional wireless charging system. Moreover, the transceiver chip 10 of the bidirectional wireless charging device provided in the embodiment of the instant disclosure integrates the power mode operation module 103 and the charging mode operation module 104 into a single chip. Thereby, the bidirectional wireless charging device 1 merely needs one control module 101 and one power stage circuit 102 to realize the bidirectional wireless charging function. Please refer to FIG. 6 , FIG. 6 shows a flow chart of a bidirectional wireless charging device of one embodiment of the instant disclosure in the power mode. The steps of process shown in FIG. 6 are applied to the above bidirectional wireless charging devices 1 and 1 ′. The Step S 601 is starting the powering process. The Step S 602 is making the bidirectional wireless charging device 1 turn into the power mode. The switch signal can be sent from the switch signal generating unit of the bidirectional wireless charging device 1 or from the switch signal generating unit of another bidirectional wireless charging device (such as the bidirectional wireless charging device 1 ′). The Step S 603 is that the bidirectional wireless charging device 1 starts to output the electromagnetic energy to the bidirectional wireless charging device 1 ′. The Step S 604 is that the bidirectional wireless charging device 1 receives and demodulates a PWM signal PWM′ sent by the bidirectional wireless charging device 1 ′, so as to obtain a status message of the bidirectional wireless charging device 1 ′, which includes an electric quantity in formation of the charging end, an energy adjusting request, an energy maintaining request or a cut-off supply request. The Step S 605 is that the bidirectional wireless charging device 1 determines whether the status message includes a cut-off supply message. If the status message includes a cut-off supply message, it goes to the Step S 606 , and if the status message does not include a cut-off supply message, it goes to the Step S 607 . The Step S 606 is that the bidirectional wireless charging device 1 adjusts the power output by the power stage circuit according to the status message and that it returns to the Step S 603 so as to continue to charge the bidirectional wireless charging device V. The steps for the bidirectional wireless charging device 1 adjusting the power output by the power stage circuit are the same as the above embodiment, and thus the redundant information is not repeated. The Step S 606 is that the bidirectional wireless charging device 1 stops outputting the electromagnetic energy, and the Step S 607 is ending the powering process. Please refer to FIG. 7 , FIG. 7 shows a flow chart of a bidirectional wireless charging device of one embodiment of the instant disclosure in the charging mode. The steps of the process shown in FIG. 7 are also applied to the above bidirectional wireless charging devices 1 and 1 ′. The Step S 701 is starting the charging process. The Step S 702 is that the bidirectional wireless charging device 1 ′ receives a switch signal and turns into the charging mode. The Step S 703 is that the bidirectional wireless charging device 1 ′ receives a PWM signal PWM from another bidirectional wireless charging device (such as the bidirectional wireless charging device 1 ), so as to charge based on the electromagnetic energy of the PWM signal PWM. The Step S 704 is that the bidirectional wireless charging device 1 ′ converts the electromagnetic energy into a regulated voltage and provides the regulated voltage to the power storage unit 13 ′ for charging. The Step S 705 is that control unit 1010 ′ of the bidirectional wireless charging device 1 ′ determines whether the power provided from the power storage unit 13 ′ to the bidirectional wireless charging device 1 ′ is within a normal range. As described above, those skilled in the art can set this normal range of power provided by the power storage unit 13 ′ based on need. If the power provided by the power storage unit 13 ′ is within the normal range, it goes to the Step S 706 . If the power provided by the power storage unit 13 ′ is not within the normal range, it goes to the Step S 707 . The Step S 706 is that the control unit 1010 ′ determines whether the power stored in the power storage unit 13 ′ reaches a predetermined value. If the control unit 1010 ′ determines that the power stored in the power storage unit 13 ′ reaches the predetermined value, it goes to the Step S 708 , otherwise it goes to the Step S 707 . As described above, those skilled in the art can set a predetermined value of power stored in the power storage unit 13 ′ based on need. The Step S 707 is that the control unit 1010 ′ makes the modulation unit 1041 ′ drive the coil 11 ′ to generate a PWM signal PWM′ including an energy adjusting request or an energy maintaining request, so as to inform the bidirectional wireless charging device 1 of its electric quantity information. After the bidirectional wireless charging device 1 receives the PWM signal PWM′, it adjusts the output power according to the status message of the PWM signal PWM′ and continues to provide the electromagnetic energy to the bidirectional wireless charging device 1 ′. The Step S 708 is that the power stored in the power storage unit 13 ′ reaches the predetermined value, so the control unit 1010 ′ makes the modulation unit 1041 ′ drive the coil 11 ′ to generate a PWM signal PWM′ including a cut-off supply request. After that, the bidirectional wireless charging device 1 ′ outputs the PWM signal PWM′ to the bidirectional wireless charging device 1 , so that that bidirectional wireless charging device 1 stops charging the bidirectional wireless charging device 1 ′. The Step S 709 is ending the charging process. To sum up, the bidirectional wireless charging device provided by the instant disclosure can be used as a powering end or a charging end to improve the convenience of the bidirectional wireless charging device. Moreover, compared with the traditional bidirectional wireless charging device, the transceiver chip of the bidirectional wireless charging device provided by the instant disclosure integrates the power mode operation module and the charging mode operation module into a single chip. Thereby, merely one control module and one power stage circuit are needed for the instant disclosure to provide the bidirectional wireless charging function, which effectively shrinks the circuit area, decreases the cost and also reduces the system complexity. In addition, in the transceiver chip provided by the embodiment of the instant disclosure, the power mode operation module and the charging mode operation module are set to use one control module and one power stage circuit together, and the number of pins of the transceiver chip also decreases. In detail, in the power mode, part of the pins of the transceiver chip can be necessarily used for powering. When switching to the charging mode, the above part of the pins would be necessarily used with the change of the transceiver chip's mode. In other words, part of the pins of the transceiver chip is used both in the power mode and the charging mode. Thereby, the number of pins of the transceiver chip can be decreased, which effectively reduces the cost of the transceiver chip. Moreover, the traditional bidirectional wireless charging device using the electromagnetic induction technology would lose some power after electromagnetic transduction because of the external circuit, which decreases the power obtained by the bidirectional wireless charging device. The bidirectional wireless charging device provided by the embodiment of the instant disclosure integrates the switching circuit, the rectifying circuit and the demodulation circuit into a single transceiver chip, which reduces the power loss and thus increases the efficiency of the bidirectional wireless charging device. The bidirectional wireless charging device provided by the embodiment of the instant disclosure also provides an automatic charging function. When there is not sufficient power, the bidirectional wireless charging device would automatically search for a nearby bidirectional wireless charging device for charging, so that the user need not manually operate the bidirectional wireless charging device for charging. The descriptions illustrated supra set forth simply the preferred embodiments of the instant disclosure; however, the characteristics of the instant disclosure are by no means restricted thereto. All changes, alterations, or modifications conveniently considered by those skilled in the art are deemed to be encompassed within the scope of the instant disclosure delineated by the following claims.

The present disclosure illustrates a bidirectional wireless charging device. The bidirectional wireless charging device comprises a transceiver chip which is configured to receive a switch signal. The transceiver chip comprises a power stage circuit and a control module. The power stage circuit is coupled to a coil, and the control module is coupled to the power stage circuit. The power stage circuit is configured to output a voltage to the coil, or to receive an induced voltage from the coil. The control module is configured to control the transceiver chip to enter a power mode or a charging mode based upon the switch signal. When the transceiver chip enters the power mode, the transceiver chip provides the voltage to the coil. When the transceiver chip enters the charging mode, the transceiver chip receives the induced voltage from the coil and charges a power storage unit.

BACKGROUND OF THE INVENTION The device of the present invention provides for the permanent recording of the various acts of patient care which are performed. The tape is of such length that a minimum of 30 days permanent recording is provided. The area in which the entry is made is covered by a slide unit which is movable between a position in which an entry can be made and a closed position in which, after an entry has been made, the entry is hidden from view. When the slide is then moved forwardly to permit an additional entry on the tape, the tape is advanced and the previous entry is moved forward out of sight. Therefore, at no time after an entry is completed can it be seen to identify the time or the type of entry previously made except by an authorized person. Thus, it is impossible for an unauthorized person to identify when the patient was last cared for. Further, no hospital employee can be aware of another staff member's entry. This prevents multiple entries to cover up any lack of regular patient inspection. Personnel will thus be protected if a patient is inspected as required by law on a regular basis by an assigned aide or nurse. Thus, the hospital and personnel will have a permanent record to present at any legal hearing should one occur. In addition, the time of wet-bed change is immediately recorded as are patient meals. If a patient does not partake of the food served, this fact can also be noted and the time recorded. Patient body position changes will be noted as to time, thus minimizing decubitus disputes. This is of extreme importance because a position change is required every 2 hours for a patient confined to a bed. The Director of Nurses can note the time she checked on the patient so that patient accident and incidents are lessened, preventing increased insurance rates. The device makes it impossible to leave space available for nurse's notes for a later nurse's protection. The charts would not coincide. State personnel and Director of Nurses, only, will have a key to the patient care recording unit for instant removal to verify verbal nursing comments. Nursing personnel cannot dispute poor patient care should a dispute arise as to their personnel records. In many states, citations are issued and fines levied. Also many citations must be posted on the wall of the hospital. By eliminating citations and any fines imposed prevents embarrassment to the hospital relative to patient care. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing the device in position on the foot board of a bed. FIG. 2 is a partial perspective view showing the tape in position for recordation of a nurse's entry. FIG. 3 is a perspective view illustrating the construction of the device and the manner of providing the tape. FIG. 4 is a plan view of the device. FIG. 5 is a section taken along the line 5--5 in FIG. 4. FIG. 6 is a view taken along the line 6--6 in FIG. 5. FIG. 7 is a view taken along the line 7--7 in FIG. 5. FIG. 8 is a perspective view of a modified form of the device. FIG. 9 is a plan view of the device shown in perspective in FIG. 8. FIG. 10 is a section taken along line 10--10 in FIG. 9. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the recording device of this invention, generally indicated at 11, is mounted on a foot board 12 of a patient's bed by flanges 13 which depend from the device and fit over the foot board. The device is retained in place by screws 14 which force plate 15 into tight engagement with the foot board 12 (see FIG. 7). The device includes a receptable 16 closed by a removable door 17, the latter being adapted to be locked in a closed position by lock 18. Mounted upon side wall 19 of the device is a fixed shaft 21 and a movable shaft 22. Shaft 21 provides a support for a roll of tape 23, the tape being fed from that roll over a support 24 and thence about a second roll 26 on shaft 22. Roll 26 has a keyway 27 thereon fitting a key 28 on roll 22. To advance the tape from roll 23 to roll 26, I provide a ratchet wheel 31 on shaft 22, the latter having a plurality of ratchet teeth 32, the teeth being successfully engaged by a pawl 33 held against the ratchet wheel 31 by spring 36. Pawl 33 is mounted on a bracket 37 secured on the underside of the slidable top 38. Slidable top 38 is supported on the top of the device in channel 39. When the movable top 38 is pushed in the direction of the arrow in FIG. 2 by engagement with its handle 41, the tape is advanced one step to provide a fresh writing surface upon which an entry can be made by a nurse or other authorized personnel. It is impossible to back up the tape because of the engagement of the ratchet wheel 31 with a dog 43 hinged as at 44 on the side wall 19 under the pressure of a spring 46. When the movable top 38 is returned to a position in which the entry on the tape is concealed, the tape remains in this position until the movable top 38 is again advanced to open position to expose a length of tape so that a fresh entry can be made. Previous entries are wound up upon the roll 26 and thus cannot be viewed by one not having means to operate the lock 18. In that form of the device shown in FIGS. 8, 9 and 10, the recording device is generally indicated at 51. This includes a door 52 hinged as at 53 along the bottom edge of the device. Shafts 54 and 55 are mounted in spaced relation upon vertical side wall 56. A roll of tape 57 is mounted upon shaft 54 and tape from this roll passes upwardly over a writing shelf 58 mounted beneath an opening 59 in the top 61 of the device. The tape extends to a spool 62 mounted upon shaft 55 which spool is in driving engagement with the shaft 55. Mounted upon shaft 55 is a ratchet wheel 63 which is effective to rotate shaft 55. Rotation of the shaft 55 is effected by means of a pawl 64 which is selectively engaged with ratchet wheel 63 under the tension applied by spring 65. The pawl is made in the form of a bell crank, one end of which is hinged as at 66 on a lever 67 which is fixed on the underside of slidable top 68. The slidable top has handle 69 and is movable therewith between a closed position, as appears in FIGS. 8, 9 and 10, and the forward position in which slidable top is advanced to expose that portion of the tape supported on the shelf 58 immediately below opening 59 in top 61. When it is desired to make an entry on the tape, the lever 67 is advanced from the full line position in which it appears in FIGS. 8, 9 and 10 to the dotted line position shown in FIG. 10. Movement of the top by the lever 67 is effective to rotate the ratchet and so advance the tape, thus withdrawing the previous entry from view and winding the tape up on spool 62. When the entry has been completed, the arm 67 is moved to the right in FIG. 10 which serves to retract the pawl to its starting position in which it can again advance the ratchet wheel. If it is desired to remove the tape from the device for examination, this can be achieved quite readily by opening the lock 18 and lowering the door 52. Shaft 54 is formed with a square recess 71 in which one can insert the end of key 72 to permit rotation of shaft 54 and return of the tape from spool 62 during the rotation of shaft 54. It is, of course, necessary for one to move the pawl 64 from engagement with the ratchet wheel 63 so that the latter may be rotated in a clockwise direction. The unit is not necessarily limited to bed attachment but may also be used in any area associated with a patient's care and requiring verification of either time or events pertinent for future reference.

A device is provided for recording written information dealing with the care of a patient. Each additional entry advances the previous entry and records it as a permanent record on the same tape roll. Each earlier entry is thereby hidden from view, thus preventing the alteration of records.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a device for exchanging objects, in particular writing instruments, between two holders embodied substantially alike and open at one side. To effect the transfer of an object by means of the approach of their open sides oriented toward one another, these holders are movable relative to one another in a plane which extends substantially at right angles to their longitudinal axes. 2. Brief Description of the Prior Art In a known device of this kind (described in German published application, DE-OS No. 29 13 690), a change of writing instruments is to be accomplished in a computer-controlled drawing system. A writing instrument is held in the holder of the drawing head by two leaf springs, disposed opposite one another, with ends lightly gripping the writing instrument and pressing it against a stationary inner face, located opposite the opening in the holder, of the receiving area. The free ends of the leaf springs protrude somewhat in the direction of the transfer of the writing instrument to the holder of the instrument magazine, and the holder in the instrument magazine has two correspondingly embodied springs. If the writing instrument is held in the holder of that drawing head and the drawing head approaches the instrument magazine, then in this state the free ends of the springs of the holder provided in the instrument magazine are located closer together, because of the absence of one writing instrument, than the free ends of the springs of the holder in the drawing head, which are spread apart by the writing instrument inserted between them. As a result, the free ends of the springs of the instrument magazine come into contact with the outer circumference of the writing instrument, and upon the further approach of the drawing head toward the instrument magazine these free ends are spread apart. As a consequence, they touch the protruding free ends of the springs of the holder in the drawing head and push their way in between these springs and the writing instrument, until they come to engage the writing instrument and thereby withdraw it from the holder of the drawing head upon the reversal of the movement of the drawing head. When a writing instrument is inserted from the instrument magazine into the drawing head, the springs of the holders function in the same manner as described above, but in this case the springs of the holder of the drawing head push their way in between the springs of the holder of the instrument magazine and the writing instrument. Although this known device for exchanging writing instruments functions relatively simply and reliably, it has the disadvantage that the position of the writing instrument in the holder of the drawing head is not defined precisely, because it is substantially determined by the characteristics of the two springs, which can vary with use. As a result, it may happen that when exchanging one writing instrument producing a particular line width for another which produces a line of different width, for instance, and attempting with the new instrument to continue a line drawn by the old instrument, the new line having the different width will not be centered precisely with respect to the line segment drawn previously. SUMMARY OF THE INVENTION It is the object of the invention to create a device of simple structure for exchanging objects, in particular writing instruments, in which the position of the object in a holder is precisely defined and does not undergo any variation, even with long use. In order to attain this object, a device of the general type discussed above is embodied in such a manner that the object is held in a receptacle having an uneven number of sides, and in cross section substantially having the shape of a regular, convex n-gon. At each corner, the receptacle has an element of ferromagnetic material or a permanent magnet, all these elements being disposed at the same level. In the receiving area, each holder has on the inner face located opposite its open side either a permanent magnet or an element of ferromagnetic material, disposed on the same level as the elements of ferromagnetic material or permanent magnets on the receptacle. Finally, the receptacle, which is held in a holder by means of the aligned position of an element of ferromagnetic material and a permanent magnet, can be rotated by an integral multiple of half the inside angle of the n-gon upon approaching the other holder as a result of the engagement therewith, and it can be transferred into the other holder by means of the aligned position of an element of ferromagnetic material and a permanent magnet. In the device according to the invention, the fixation of the object, or of the receptacle containing the object, in a holder is thus effected by means of magnetic force--that is, in a non-wearing manner--so that even after long use the position in which the object is held inside the holder always remains the same. For transfer to the other holder, because of the approach of the two holders toward one another, the receptacle containing the object is rotated about its longitudinal axis in such a manner that the areas which attract one another because of magnetic force are displaced relative to one another, and corresponding areas in the other holder which also attract one another magnetically are brought into an aligned position. That is to say, the receptacle of the other holder is attracted magnetically and is fixed in this holder in a position which is replicable even after a long period of use. As a result of the rotation of the receptacle, the holder originally containing this receptacle no longer holds it by magnetic force, because the rotation has instead effected a magnetic fixation of the receptacle in the other holder. Hence, it is now possible to remove the other holder together with the receptacle from the holder which had originally fixed this receptacle. In order to keep the receptacle in the holder in a position which is precisely aligned in the axial direction, each holder and the receptacle can have two groups of permanent magnets and of elements of ferromagnetic material disposed spaced apart axially from one another, at uniform distances from one another. As a result, the receptacle in the holder is thus held at two areas located at an axial distance from one another by magnetic force, and the axial alignment of the receptacle is thus assured. In the receiving area of each holder, at least one guide face for the receptacle may be provided between the groups, so that during the transfer operation this receptacle is put into the desired position in the holder by the guide face. In addition, the receptacle can be brought into an engagement with the associated holder such that it cannot be shifted in the axial direction. For instance, by an engagement between the guide face and a recess provided on the receptacle. By this means, it is also possible to fix the height of the receptacle relative to the holder in a replicable manner. In the simplest design of the receptacle, it may in cross section have substantially the shape of a triangle. In order to attain the rotation of the receptacle in one holder upon approaching the other holder or being approached thereby, at least one portion of the opposing free edge areas of the open sides of the holders may protrude to different extents, beyond the inner face of the receiving area which carries the permanent magnet or the element of ferromagnetic material. As a result, the edge area of the holder not containing the receptacle (which protrudes farther out) comes into contact with the receptacle sooner than the other free edge area (which does not protrude as far) so that a rotation of the receptacle is thereby effected. With the free edge areas of the open sides of the holders embodied in such a manner, the longitudinal axes of the holders may be located, in the transfer position: on a first straight line extending through the centers of the permanent magnets or elements of ferromagnetic material, provided therein. In order to be moved away from one another, the holders can be movable relative to one another along this line. Upon approaching one another, the holders can be movable relative to one another along a second straight line which extends at an acute angle from the first line, for instance at an angle of 35° to 50° (and preferably from 40° to 45°), and passes through the longitudinal axes of the holders. When the device is embodied in such a manner, the approach of the holders to one another is thus effected along a straight line which is different from the straight line along which the holders are moved apart from one another. The invention will now be described in detail, referring to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1, in a simplified perspective view, shows a plotter in which a holder of a device for exchanging writing instruments may be seen; FIG. 2, in perspective views, shows two holders, one of which holds the writing instrument receptacle; FIG. 3 is a different view of one of the holders of FIG. 2; FIG. 4 is a section taken along the line IV--IV of FIG. 3; FIG. 5 is a section taken along the line V--V of FIG. 3; FIG. 6 is a vertical section taken through the writing instrument receptacle of FIG. 2; FIG. 7 is a section taken along the line VII--VII of FIG. 6; FIGS. 8-12 shows the positions of a holder in sequence in the course of the removal of the receptacle from a stationary holder; and FIGS. 13-17 show the positions of a holder in sequence in the course of the transfer of the receptacle from this holder to the stationary holder. DESCRIPTION OF THE PREFERRED EMBODIMENT The invention will be described herein in terms of a device for exchanging writing instruments, such as may be used in the conventional flat bed plotter 1 shown in FIG. 1, which has a bar 2 that can be moved back and forth in one direction over the drawing surface 3, and a holder 5 secured to bar 2 by means of a drawing head, not shown. The drawing head is movable back and forth on the bar 2 in the longitudinal direction thereof in the conventional manner. Magazines 4 for writing instruments are also present on the stationary frame of the plotter 1, and are shown in a highly simplified and schematic manner. Holders not shown, but corresponding to the holder 5, are secured in these instrument magazines 4. Two holders 5, 5' of identical design are shown in FIG. 2, each in the approximate shape of half a cylindrical shell, the holders facing one another with their open sides. The various parts of the two holders are identified with the same reference numerals, but those of one holder, which will later be assumed to be the stationary holder, are marked with a prime ('). Because the design of the two holders is the same, it will be sufficient to describe only one holder in detail. The holder 5, which by way of example is of plastic or non-ferromagnetic metal, has two permanent magnets 6, 7 on its inner face located opposite the open side. The permanent magnets 6, 7 are located on a straight line, extending parallel to the longitudinal axis and are spaced apart axially from one another. Between these permanent magnets, upon the inner face is a protruding guide face 9, and an oblong slot 8 which is provided on a connecting line drawn between the permanent magnets 6 and 7, in the vicinity of the guide face. The holder can be secured on some component of the exchanging device, for instance on the bar 2 or on an instrument magazine 4 of the plotter (FIG. 1), by means of this oblong slot 8. As is shown more particularly in FIG. 2 and 5, one lateral limiting wall of the receiving area of the holder 5 is longer than the other lateral limiting wall, so that free edge area 11 is more remote from the permanent magnets 6, 7 than is free edge area 10. In the assembled state, the longer lateral wall area of one holder (for instance holder 5), is located with its free edge area 11 opposite the shorter wall area of the other holder (for instance holder 5')--that is, opposite the free edge area 10' (FIG. 2)--so that when the holders 5, 5' have made their full approach toward one another and are fully in alignment, they approximately form a ring. In FIG. 2, a receptacle 20 is held in the holder 5' and has a substantially triangular cross section with rounded corners (FIG. 7). A central bore 21 extends through this receptacle 20 along its longitudinal axis. When the receptacle 20 is positioned in one of the holders, its longitudinal axis coincides with that of the holder, for instance the longitudinal axis 12' of the holder 5' in FIG. 2. The central bore 21 serves to receive the objects which are to be exchanged for one another and is therefore adapted in its shape and size to the shape and size of the objects. Elements 22, 23, 24 of ferromagnetic material are provided on each corner of the receptacle 20 in a common radial plane, and elements of ferromagnetic material having the same shape as the elements 22, 23, 24 are disposed, at a distance from the latter which is equal to the distance between the permanent magnets 6, 7 in the holder 5, on each corner of the receptacle in a second radial plane; of these, only the element 25 is shown in FIG. 6. In the vicinity of each corner, a groove extending in the circumferential direction is embodied between the elements of ferromagnetic material spaced apart axially from one another. In FIG. 6 only the groove 26 is shown, located between the elements 22 and 25. The size of these grooves in the direction of the longitudinal axis of the receptacle 20 corresponds to the length of the guide face 9 of the holder 5 in the direction of the longitudinal axis 12. Hence, when the receptacle 20 is inserted in the holder 5, the guide face 9 engages this groove and reliably prevents a shift in position of the receptacle inside the holder in the direction of the longitudinal axis 12. The receptacle 20, like the holder 5, may be fabricated of plastic or of non-ferromagnetic metal. If the position of the holders 5, 5' and of the receptacle 20 as shown in FIG. 2 is taken as the point of departure, then the resultant sectional illustration (extending in the same plane as section V--V of FIG. 3 taken through the holder 5 and section VII--VII of FIG. 6 taken through the receptacle) is shown in FIG. 8. In FIG. 8 the receptacle 20 is seated within the holder 5', and the guide face 9' extends within the corresponding groove of receptacle 20, which is provided in the corner area between the ferromagnetic material element 23 and the ferromagnetic material element provided some distance beneath it. In this position, the central axis of the permanent magnet 6' is located on the central axis of the element of ferromagnetic material 23, so that these two elements attract one another by magnetic force. A permanent magnet 7' (not shown in FIG. 8), attracts an adjacent element of ferromagnetic material of the receptacle 20 in the same manner. The central axis of the receptacle 20 is located in the central axis 12' of the holder 5'. The holder 5 is located at a distance from the holder 5' and offset laterally somewhat therefrom. Its central axis 12 is located on a straight line 14, which extends through the central axis 12' of the holder 5'. Straight line 14 is shown intersecting the straight line 13, which passes through the centers of the permanent magnet 6' and of the element 23 of ferromagnetic material as well as through the central axis 12', at an acute angle of approximately 41. In order to effect transfer of the receptacle 20 from the holder 5' to the holder 5, the holder 5 is moved out of the position shown in FIG. 8, in which the open sides of the holders 5, 5' are oriented toward one another, toward the holder 5' in the plane of the drawing without tilting or twisting in such a manner that the central axis 12 of the holder moves along the line 14. As a result of this approach, the free edge area 11 of the holder 5 comes into contact with the corner of the receptacle 20 in which the element 22 of ferromagnetic material is located (FIG. 9). Further, upon approaching still closer, the free edge area 11 rotates the receptacle 20 counterclockwise in the holder 5 (FIG. 10). During this rotation, the guide face 9' remains in engagement with the groove between the element 23 and the element of ferromagnetic material located below it. Hence, an axial shifting of the receptacle is not possible, although the element 23 of ferromagnetic material is moved out of the vicinity of the permanent magnet 6' and the element of ferromagnetic material located below this element 23 is correspondingly moved out of the vicinity of the permanent magnet 7' and the holder is thereby raised as a result of magnetic force. Once the holder 5 has approached the holder 5' to its closest extent, and the axis 12 of the holder 5 and the axis 12' of the holder 5' to its closest extent, and the axis 12 of the holder 5 and the axis 12' of the holder 5' coincide (FIG. 11), then the receptacle 20 has been rotated to such an extent that the ferromagnetic elements 22 and 23 of the receptacle 20 are at a great distance from the permanent magnet 6', while the element 24 of ferromagnetic material is in alignment with the permanent magnet 6 of the holder 5. Thus, the element of ferromagnetic material located below the element 24 is also in alignment with the permanent magnet 7, and the receptacle 20 is thus attracted by the permanent magnets 6 and 7. The axial positioning of the receptacle 20 is thereby effected, in the same manner as with the movement and the restraint of the receptacle 20 in the holder 5', by means of the engagement of the guide face 9 with the groove provided between the element 24 and the element of ferromagnetic material located below it. Since in the position shown in FIG. 11 the receptacle 20 is thus held by the holder 5 by magnetic force, yet there is no longer any magnetic force existing between the receptacle 20 and the holder 5', it is possible to remove the receptacle 20 from the holder 5' by moving the holder 5 with its longitudinal axis 12 along the straight line 13, and the receptacle 20 can then be moved away together with the holder 5 (FIG. 12). Should it be desired to transfer the receptacle 20 from the movable holder 5 to the stationary holder 5', the holder 5 is shifted parallel to the straight line 13. Thereby, central axis 12 of movable holders is located on a straight line 15 extending parallel to the straight line 13 (FIG. 13). Subsequently, an approaching movement of the holder 5 toward the holder 5' takes place, in which the central axis 12 of the holder 5 is moved along the straight line 14 (FIG. 14), as in the case of the approach movement described earlier. The result is that the free edge area 11' of the holder 5' comes into contact with the receptacle 20 having the element 23 of ferromagnetic material. If this approach movement is continued, and as a result of this engagement, a counterclockwise rotation of the receptacle 20 inside the holder 5 occurs. Consequently, the element 24 of ferromagnetic material moves clear of the permanent magnet 6 and the element of ferromagnetic material located below the element 24 moves clear of the permanent magnet 7 (FIG. 15). This approaching movement ends when the longitudinal axis 12 of the holder 5 coincides with the longitudinal axis 12' of the holder 5' (FIG. 16). In this position, the element 22 of ferromagnetic material and the permanent magnet 6' (like the element 25 of ferromagnetic material 25 and the permanent magnet 7'), are located opposite one another, while no restraining magnetic force remains between the receptacle 20 and the holder 5. In this position for receptacle 20, the holder 5 can thus be removed from the holder 5' by moving it with its longitudinal axis 12 along the line 13, and the receptacle 20 will be held in the holder 5' by magnetic force (FIG. 17). In the above description, it has been assumed that permanent magnets are provided in the holders, while elements of ferromagnetic material are provided in the receptacles. Naturally it is also possible to replace the permanent magnets in the holders with elements of ferromagnetic material instead and then to replace the elements of ferromagnetic material in the receptacle with permanent magnets. The only criterion is that with a corresponding, aligned positions of the permanent magnet and the element of ferromagnetic material, a magnetic force should be exerted between the holder and the receptacle which keeps these parts together. While a preferred embodiment of the invention has been shown and described, the invention is to be limited solely by the scope of the appended claims.

In a device for exchanging objects, in particular writing instruments, two substantially identically embodied holders (5, 5') which are open at one side are provided. These holders are movable relative to one another in a plane extending substantially at right angles to there longitudinal axes (12, 12'). The object to be exchanged is held in a receptacle (20), which in cross section has substantially the shape of a regular, convex n-gon having an uneven number of sides. At each corner of the receptacle (20), there is an element of ferromagnetic material (22, 23, 24), and there is a permanent magnet (6, 6') on the inner face, located opposite the open side, of the receiving area of each holder (5, 5'). The receptacle (20) is positionally fixed in a holder (for instance, 5') by means of the aligned position of an element (23) of ferromagnetic material and of a permanent magnet (6', for example). By means of an approach toward the other holder (5'), the receptacle (20) is rotated, so that the permanent magnet (6) of the other holder (5) enters into an aligned position with one element (24) of ferromagnetic material of the receptacle (20), while the magnetic effect between the receptacle (20) and the one holder (5') is broken (FIG. 8).

This application is a continuation-in-part of U.S. application Ser. No. 10/143,380, filed May 10, 2002 now abandoned (which is incorporated in its entirety as a part hereof), which claimed the benefit of U.S. Provisional Application No. 60/290,297, filed May 11, 2001. FIELD OF THE INVENTION This invention relates to antimicrobial polyester-containing articles and methodology for the preparation of antimicrobial polyester-containing articles utilizing chitosan and chitosan-metal complexes as the antimicrobial agent. TECHNICAL BACKGROUND OF THE INVENTION This invention relates to the use of chitosan and chitosan-metal complexes to generate polyester-containing articles having antimicrobial properties. PCT application WO 00/49219 discloses the preparation of substrates with biocidal properties. The deposition of solubilized chitosan on polyester, among other materials, followed by treatment with silver salts, reduction of the silver salt and crosslinking the chitosan is disclosed to yield a durable biocidal article. The application also discloses the crosslinking of the chitosan after it is applied, either before or after the silver salt treatment. JP Kokai H9-291478 discloses a process for the application of a chitosan derivative to polyester fabric comprising UV treatment of the polyester fabric followed by application of a chitosan-derived quaternary ammonium base. The UV irradiation serves to generate free radicals on the surface of the polyester fabric to which the chitosan is subsequently attached. H. Shin et al, Sen - I Gakkaishi, 54(8), 400–406 (1998) discloses similar UV fabric treatment and also a low temperature air plasma treatment prior to chitosan treatment. JP Kokai H8-22772 discloses a process for the manufacture of an antibacterial acrylic yarn which comprises dipping, in an aqueous acidic chitosan solution, a wet spun yarn from an acrylonitrile-based polymer solution, neutralizing with an aqueous alkali solution, drying and densifying. The process may be carried out batch-wise or continuously. The chitosan is absorbed on the surface of the yarn and deposited in micro-voids within the yarn before drying. S. Matsukawa et al., Sen - I Gakkaishi, 51(1), 51–56 (1995) disclose the modification of polyester fabrics using chitosan. The polyester was hydrolyzed with caustic soda, neutralized with 1% acetic acid solution, then treated with a chitosan solution and, optionally, with a crosslinking agent. SUMMARY OF THE INVENTION This invention provides an antimicrobial polyester-containing article having chitosan grafted onto the article and optionally, containing one or more metal salts, one or more carboxyl-containing polymers or combination thereof. Further disclosed is a process for preparing antimicrobial polyester-containing articles comprising the sequential steps of: (a) providing a polyester-containing article; (b) contacting the polyester-containing article with a basic solution; (c) optionally, washing the article produced in step (b); (d) contacting the article produced in step (b) or step (c) with a strong mineral acid solution; (e) optionally, washing the article produced in step (d); (f) contacting the article produced in step (d) or step (e) with a solution comprising a chitosan agent selected from the group consisting of chitosan, chitosan salts and chistosan derivatives; (g) optionally, heating the article produced in step (f); (h) isolating the article produced in step (f) or step (g); and (i) optionally, heating the article isolated in step (h) at a temperature higher than the temperature of step (g). Further disclosed is a continuous process for producing an antimicrobial polyester-containing article comprising the sequential steps of: (a) providing a feed station on which is disposed a polyester-containing article and a take-up station capable of receiving the polyester-containing article; (b) drawing the article from the feed station through a first treatment station wherein said article is exposed to a basic solution; (c) optionally drawing the step (b)-treated article through a second treatment station wherein the article is exposed to water; (d) drawing the step (b)- or step (c)-treated article through a third treatment station wherein the article is exposed to a strong mineral acid solution; (e) optionally, drawing the step (d)-treated article through a fourth treatment station wherein the article is exposed to deionized water; (f) drawing the step (d)- or step (e)-treated article through a fifth treatment station wherein the article is exposed to a solution comprising a chitosan agent; (g) optionally, heating the step (f)-treated article after it exits the chitosan treatment station; and (h) causing the step (f)- or step (g)-treated article to be received on and accumulate on the take-up station. BRIEF DESCRIPTION OF THE DRAWINGS The drawings consist of 20 figures as follows: FIG. 1 is a diagram showing the antimicrobial effect of chitosan grafted on 3GT knit fabric vs. Listeria monocytogenes ATCC 15313. FIG. 2 is a diagram showing the antimicrobial effect of chitosan grafted on 2GT knit fabric vs. Klebsiella pneumoniae ATCC 4352. FIG. 3 is a diagram showing the antimicrobial effect of chitosan grafted on 2GT knit fabric vs. Candida albicans ATCC 10231. FIG. 4 is a diagram showing the antimicrobial effect of chitosan grafted on 3GT woven fabric vs. Staphylococcus aureus ATCC 6538. FIG. 5 is a diagram showing the antimicrobial effect of chitosans of various molecular weights grafted onto 2GT woven microfiber fabric vs. E. coli ATCC 25922. FIG. 6 is a diagram showing the antimicrobial effect of chitosans of various molecular weights grafted onto 2GT woven microfiber fabric vs. Staphylococcus aureus ATCC 29213. FIG. 7 is a diagram showing the antimicrobial effect of chitosan grafted onto 3GT fabrics with and without silver nitrate treatment vs. Salmonella cholerasuis ATCC 9239. FIG. 8 is a diagram showing the antimicrobial effect of chitosan grafted on 3GT fabrics with and without copper sulfate treatment vs. E. coli O157:H7. FIG. 9 is a diagram showing the antimicrobial effect of chitosan grafted on 2GT fabrics with various concentration silver nitrate solution post treatment vs. Staphylococcus aureus ATCC 6538. FIG. 10 is a diagram showing the antimicrobial effect of chitosan grafted on 2GT fabrics after various hydrolysis times with and without a 0.1% silver nitrate post treatment vs. E. coli O157:H7. FIG. 11 is a diagram showing the antimicrobial activity of free chitosan vs. grafted chitosan on 2GT fabric vs. Staphylococcus aureus ATCC 6538. FIG. 12 is a diagram showing the antimicrobial activity of grafted chitosan on 2GT knit fabrics with various after-treatments of polyacrylic acid, additional chitosan and/or silver nitrate treatment vs. E. coli 25922. FIG. 13 is a diagram showing the antimicrobial effect of chitosan grafted on 2GT fiber by processing in a package dyer vs. E. coli ATCC 25922. FIG. 14 is a diagram showing the antimicrobial effect of chitosan grafted on 2GT fiber by processing in a package dyer and single-end sizer vs. E. coli ATCC 25922. FIG. 15 is a diagram showing the antimicrobial effect of a chitosan-treated polyester and Lycra® blend fiber vs. E. coli ATCC 25922. FIG. 16 is a diagram showing the antimicrobial effect vs. E. coli ATCC 25922 of chitosan treatment of yarns commonly occurring in polyester blends. FIG. 17 is a diagram showing the antimicrobial effect of a chitosan-treated polyester/rayon nonwoven fabric vs. E. coli ATCC 25922. FIG. 18 is a diagram showing the antimicrobial effect of a chitosan-treated polyester/wood pulp nonwoven fabric vs. E. coli ATCC 25922. FIG. 19 is a diagram showing the antimicrobial effect of a chitosan-treated bicomponent (2GT/3GT) polyester fiber vs. E. coli ATCC 25922. FIG. 20 is a schematic diagram of the continuous process of the invention for making antimicrobial polyester-containing articles. DETAILED DESCRIPTION OF THE INVENTION The present invention involves the preparation of antimicrobial polyester-containing articles that have chitosan grafted thereon. Chitosan is the commonly used name for poly-[1-4]-β-D-glucosamine. Chitosan is chemically derived from chitin, which is a poly-[1-4]-β-N-acetyl-D-glucosamine which, in turn, is derived from the cell walls of fungi, the shells of insects and, especially, crustaceans. As used herein, the term “grafted” means that the chitosan is bound to the polyester substrate by either ionic (electrostatic) or covalent bonding. Grafting of the chitosan to the polyester article may be confirmed by Electron Spectroscopy for Chemical Analysis (ESCA) [see, for example, Xin Qu, Anders Wirsen, Bjorn Orlander, Anne-Christine Albertsson, Polymer Bulletin, (2001), vol. 46., pp. 223–229 and Huh, M. W., Kang, I., Lee, D. H., Kim, W. S., Lee, D. H., Park, L. S., Mln, K. E., and Seo, K. H., J. Appl. Polym. Sci. (2001), vol. 81, p. 2769]. Grafting is also established by the literature report of Ga-er Yu, Frederick G. Morin, Geffory A. R. Nobes, and Robert H. Marchessault, in Macromolecules, (1999), vol. 32, pp. 518–520). ESCA data demonstrate that the chitosan-modified surfaces of the polyester-containing articles of the present invention are similar in composition to those of the chitosan starting materials. The ESCA data also show that these surfaces have a significant level of nitrogen that is incorporated in a salt form, which provides evidence that the chitosan in physically linked to the surface through ionic interactions. Polyesters comprise those polymers prepared from diols and dicarboxylic acids. Dicarboxylic acids useable in the preparation of polyesters include, but are not limited to, unsubstituted and substituted aromatic, aliphatic, unsaturated, and alicyclic dicarboxylic acids and the lower alkyl esters of dicarboxylic acids having from 2 carbons to 36 carbons. Specific examples of the desirable dicarboxylic acid component include terephthalic acid, dimethyl terephthalate, isophthalic acid, dimethyl isophthalate, 2,6-napthalene dicarboxylic acid, dimethyl-2,6-naphthalate, 2,7-naphthalenedicarboxylic acid, dimethyl-2,7-naphthalate, 3,4′-diphenyl ether dicarboxylic acid, dimethyl-3,4′diphenyl ether dicarboxylate, 4,4′-diphenyl ether dicarboxylic acid, dimethyl-4,4′-diphenyl ether dicarboxylate, 3,4′-diphenyl sulfide dicarboxylic acid, dimethyl-3,4′-diphenyl sulfide dicarboxylate, 4,4′-diphenyl sulfide dicarboxylic acid, dimethyl-4,4′-diphenyl sulfide dicarboxylate, 3,4′-diphenyl sulfone dicarboxylic acid, dimethyl-3,4′-diphenyl sulfone dicarboxylate, 4,4′-diphenyl sulfone dicarboxylic acid, dimethyl-4,4′-diphenyl sulfone dicarboxylate, 3,4′-benzophenonedicarboxylic acid, dimethyl-3,4′-benzophenonedicarboxylate, 4,4′-benzophenonedicarboxylic acid, dimethyl-4,4′-benzophenonedicarboxylate, 1,4-naphthalene dicarboxylic acid, dimethyl-1,4-naphthalate, 4,4′-methylene bis(benzoic acid), dimethyl-4,4′-methylenebis(benzoate), oxalic acid, dimethyl oxalate, malonic acid, dimethyl malonate, succinic acid, dimethyl succinate, methylsuccinic acid, glutaric acid, dimethyl glutarate, 2-methylglutaric acid, 3-methylglutaric acid, adipic acid, dimethyl adipate, 3-methyladipic acid, 2,2,5,5-tetramethylhexanedioic acid, pimelic acid, suberic acid, azelaic acid, dimethyl azelate, sebacic acid, 1,1 1-undecanedicarboxylic acid, 1,10-decanedicarboxylic acid, undecanedioic acid, 1,12-dodecanedicarboxylic acid, hexadecanedioic acid, docosanedioic acid, tetracosanedioic acid, dimer acid, 1,4-cyclohexanedicarboxylic acid, dimethyl-1,4-cyclohexanedicarboxylate, 1,3-cyclohexanedicarboxylic acid, dimethyl-1,3-cyclohexanedicarboxylate, 1,1-cyclohexanediacetic acid, metal salts of 5-sulfo-dimethylisophalate, fumaric acid, maleic anhydride, maleic acid, hexahydrophthalic acid, phthalic acid and the like and mixtures derived therefrom. Diols useful in the preparation of polyesters include, but are not limited to, unsubstituted, substituted, straight chain, branched, cyclic aliphatic, aliphatic-aromatic or aromatic diols having from 2 carbon atoms to 36 carbon atoms. Specific examples of the desirable diol component include ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,2-, 1,3- and 1,4-butanediol, 1,5-pentane diol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, dimer diol, isosorbide, 4,8-bis (hydroxymethyl)-tricyclo [5.2.1.0/2.6]decane, 1,2-, 1,3- and 1,4-cyclohexanedimethanol, and the longer chain diols and polyols made by the reaction product of diols or polyols with alkylene oxides including di(ethylene glycol), tri(ethylene glycol), poly(ethylene ether) glycols, poly(butylene ether) glycols and the like and mixtures derived therefrom. The preferred polyesters useful herein are poly(ethylene terephthalate) (“2GT”), poly(trimethylene terephthalate) (“3GT”), and blends and copolymers thereof. The term “polyester-containing article” as used herein means an article that has a surface composition of at least 10% polyester by area. In apparel applications, garments comprising polyester often include other components, such as acrylic, wool, silk, cotton, linen, flax, hemp, rayon, cellulose, wood pulp, cellulose acetate or triacetate, nylon 6 or nylon 66, poly(m-phenylene isophthalamide) (‘PMIA,’ available from E. I. du Pont de Nemours and Company, Wilmington, Del., U.S.A. under the trademark Nomex®), poly(p-phenylene terephthalamide) (‘PPTA,’ available from E. I. du Pont de Nemours and Company under the trademark Kevlar®), polyolefins such as polypropylene and polyethylene, fiberglass, Lycra® spandex (available from E. I. du Pont de Nemours and Company), and elastomers. Polyesters other than poly(ethylene terephthalate) may also be present, for example, a copolymer with a low melt temperature that is used as a binder fiber in fiberfill. Combination of the fibers listed above can be used in the present invention for added benefits. Such fiber combinations can be prepared by any means known to those skilled in the art. “Bicomponent” filaments in which two polymers are arranged side-by-side or in a sheath-core arrangement can be formed during the spinning process. 2GT/3GT bicomponent fibers such as are disclosed in U.S. Pat. No. 3,671,379, herein incorporated by reference, are one example useful in the present invention. Another means of preparing fiber combinations is by intimate blending of staple fibers; i.e., as the staple yarn is spun, the different fibers can be combined in either a carding or drawing process. Fiber combinations can also be prepared by knitting or weaving yarns, staple, or filament of different composition into the same fabric. In the case of Lycra® spandex (E. I. de Nemours and Company, Wilmington, Del.), the spandex is added in staple yarn at either the spinning step or during fabric production, such as plating in knitting. As a first step of the process of the present invention, polyester-containing articles are pretreated. This pretreatment involves hydrolyzing the surface of said polyester-containing article to prepare it for subsequent attachment of chitosan groups. The pretreatment is achieved by the hydrolytic rupture of some of the ester bonds in the polyester-containing articles to generate carboxylate groups. The hydrolysis treatment involves exposure of the polyester-containing article to an aqueous solution of a base. All soluble Group I, II, and III hydroxides, ammonium hydroxide, and alkyl-substituted ammonium hydroxides can be used to effect hydrolysis. The base can be dissolved in water or a mixture of water with one or more water-soluble organic solvents. Examples of suitable water-soluble organic solvents include methanol, ethanol, propanol, ethylene glycol, propylene glycol, acetonitrile, dimethylformamide, and dimethylacetamide. The base useful in the invention is typically an alkali metal hydroxide, most preferably sodium hydroxide. The concentration of base in the aqueous solution is not critical and depends on the base being used and the treatment temperature. In the case of sodium hydroxide, the concentration may range from 1 to 40% by weight. The temperature of the treatment is not critical, room temperature being preferred. Temperature ranges of 10 to 90° C. may be employed. Lower temperature is preferred with the higher concentrations of base. The article is exposed to the basic solution long enough to reduce its weight by from 1 to 30 percent, preferably by from 1 to 10 percent. The treatment time will depend on the concentration and temperature of the basic solution; the higher the concentration of the base solution, and the higher the temperature employed the shorter the time of treatment. Times as low as 2 to 30 seconds can be employed successfully. Optionally, the article is then washed with water to remove the bulk of the base solution. Following the hydrolysis treatment, the article is acidified by treatment with strong mineral acid to a pH of less than or equal to the pKa of the carboxylate groups generated by the hydrolysis treatment. The article can be directly acidified with aqueous mineral or organic acids without the involvement of water washing. However, aqueous washing is preferred to minimize the use of acids. As used herein, the term “strong” mineral acid, means acids having a pH less than pH 2. Mineral acids useful herein include, for example, hydrochloric, sulfuric and phosphoric acids. Hydrochloric acid is most preferred. The time and temperature of the acidification step are not critical; times ranging from 2 seconds to 30 minutes at room temperature can be employed successfully. Optionally, the article is again washed with water to remove the bulk of the mineral acid. The article may then be used directly in the next step, or may, optionally, be dried. While not desiring to be bound by any particular theory, it is believed that the acidification below the pKa of the carboxylate groups, resulting in the formation of the free carboxylic acid group, greatly increases the rate and efficacy of the reaction of the carboxyl species with chitosan in the subsequent step. Following the acidification step, the article is treated with chitosan. This comprises soaking or wetting the article with a solution containing a chitosan agent. The term “chitosan agent” as used herein means all chitosan-based moieties, including chitosan, chitosan salt, and chitosan derivatives. The solution comprising the chitosan agent may be aqueous. However, since chitosan by itself is not soluble in water, the chitosan may be solubilized in a solution. Solubility is obtained by adding the chitosan to a dilute solution of a water-soluble, organic acid selected from the group consisting of mono-, di- and polycarboxylic acids. This allows the chitosan to react with the acid to form a water-soluble salt, herein referred to as “chitosan salt.” Alternatively, “chitosan derivatives,” including N- and O-carboxyalkyl chitosan, that are water-soluble, can be used directly in water instead of chitosan salt. . The chitosan may also be dissolved in special solvents like dimethylacetamide in the presence of lithium chloride, or N-methyl-morpholine-N-oxide. Such solubilized chitosan solutions can be used in the present invention instead of aqueous solutions containing chitosan salt or chitosan derivatives. Typically, the chitosan solution is an aqueous acetic acid solution, for example, an aqueous solution containing 2% chitosan and 0.75% acetic acid or 2% chitosan and 1.5% aqueous acetic acid. The time of treatment is typically 5 to 30 minutes. The temperature of the treatment is not critical, room temperature being preferred. After treatment with chitosan solution, excess solution may be allowed to drip out, or may be removed by wringing or spinning. Optionally, the treated article is then dried via oven drying or a combination of ambient air drying and oven drying. Articles prepared by the above methods exhibit antimicrobial properties. The term “antimicrobial” as used herein, means both bactericidal and fungicidal. In addition, the fibers and yarns processed herein exhibit favorable physical properties with respect to tenacity, elongation and hand-feel. Said antimicrobial properties may, optionally, be further enhanced by treatment with soluble metal salts, for example, soluble silver salts, soluble copper salts and soluble zinc salts. The preferred metal salts of the invention are aqueous solutions of zinc sulfate, copper sulfate or silver nitrate. The metal salts are typically applied by dipping or padding a dilute (0.1 to 5%) solution of salt in water. The degree of enhancement depends on the particular metal salt used, its concentration, the time and temperature of exposure, and the specific chitosan treatment, that is, the type of chitosan agent, its concentration, the temperature, and the time of exposure. Examples 3, 4, 5, 6 and 7; FIGS. 7 , 8 , 9 , 10 and 11 ; and Table 1 demonstrate the effect of metal salts in the process of the invention. Articles prepared by the above method of the invention also exhibit improved antistatic properties. Antistatic properties refer to the ability of a textile material to disperse an electrostatic charge and to prevent the buildup of static electricity. ( Dictionary of Fiber & Textile Technology , Hoechst Celanese Corp., Charlotte, N.C. (1990), p. 8) A further optional post-treatment comprises applying a carboxyl-containing polymer to the chitosan treated article, or to the metal salt treated chitosan treated article. The term “carboxyl-containing polymer” as used herein means a polymer that contains carboxylic acid groups in side chains attached to the polymer backbone. The carboxyl-containing polymer, most preferably polyacrylic acid, is typically applied from a dilute aqueous solution by dipping or padding. Any of the above described chitosan-treated articles, metal salt-treated articles or the carboxyl-containing polymer-treated articles, may benefit from a further chitosan solution treatment. Included within the scope of this invention are articles that, having received a first treatment with chitosan by the process of the present invention, are further subjected to one or more treatments with metal salt, carboxyl-containing polymer and/or additional chitosan in any order, with the proviso that the surface of the final article is treated with metal salt or a chitosan solution. In a preferred embodiment, the process of the invention further involves heating the chitosan-grafted polyester-containing article to a temperature of from 35° C. to 190° C. under a nitrogen or ambient atmosphere for from 30 seconds to 20 hours, washing with deionized water and further drying the article at a temperature of 35° C. to 190° C. for from 30 seconds to 20 hours. The articles of the present invention can also be produced in a continuous process. The process is illustrated by FIG. 20 of the drawings herein. Referring now to FIG. 20 , there is shown an apparatus for performing the following sequential steps of the invention: (a) A feed station ( 2 ) on which is disposed a polyester-containing article ( 1 ) is provided. The feed station would typically comprise one or more feed rollers ( 10 ). (b) The article is drawn from the feed station through a first treatment station ( 4 ) wherein said article is exposed to a basic solution. The treatment stations herein would typically be immersion bath trays or tanks. (c) The article is optionally drawn from the first treatment station through a second treatment station ( 5 ) wherein the step (b)-treated article is exposed to water. Optionally, one or any number of draw rolls ( 11 ) may help guide the article between the treatment stations. Draw rolls such as draw roll ( 11 ) may be placed along any step of the continuous process as is commonly known in the art. (d) The article from the second treatment station is drawn through a third treatment station ( 6 ) wherein the step (c)-treated article is exposed to a strong mineral acid solution. (e) Optionally, the article from the third treatment station is drawn through a fourth treatment station ( 7 ) wherein the step (d)-treated article is exposed to water. (f) The article is then drawn through a fifth treatment station ( 8 ) wherein the step (d)- or step (e)-treated article is exposed to a solution comprising the chitosan agent. As discussed above, the chitosan agent is selected from the group consisting of chitosan, chitosan salts and chitosan derivatives. The treatment stations would typically be immersion bath trays or tanks. (g) Optionally, the step (f)-treated article is heated by a heater, such as a heater roll assembly ( 9 ) after it exits the chitosan treatment station. (h) The step (f)- or step (g)-treated article is then received on and accumulates on the take-up station ( 3 ). The treated article would typically be wound by means of a traversing guide ( 12 ) onto the take-up station ( 3 ) which is typically one or more cardboard or resin tubes to form spinning bobbins. The feed station, treatment stations, heaters, and take-up components may be any convenient means known in the art for continuous treatment of fibers and yarns (see, for example, Ullmann's Encyclopedia of Industrial Chemistry , fifth Edition, Wolfgang Gerhartz, Executive Editor, Volume A10, VCH Verlagsgesellschaftg, Weinheim, Federal Republic of Germany (1987), “Fibers, 3. General Production Technology,” H. Lucker, W. Kagi, U. Kemp, and W. Stibal, pp. 511–566). The continuous process is particularly appropriate for treating polyester-containing fiber or yarn on a commercial scale. The process and articles of the present invention do not employ crosslinking agents which makes the process more efficient and economical than other currently available processes requiring the use of crosslinking agents. The phrase “crosslinking agent” connotes the commonly used di- or tri-functional crosslinking agents known in the art. The carboxyl-containing polymers, e.g. polyacrylic acids, are not construed to be crosslinking agents in the context of the present invention. The preferred articles of the present invention are in the form of fibers; fabrics, including wovens and nonwovens; filaments; films; and articles and constructs prepared therefrom. The antimicrobial articles of the invention shall find application in uses such as apparel, including sportswear, activewear, intimate apparel, swimwear and medical garments; healthcare, including medical drapes, antimicrobial wipes, surfaces (counters, floors, walls), personal hygiene products and medical packaging; household articles, including fiberfill, bedding, window treatments and surfaces; and food processing/service, including packaging, absorbent antimicrobial pads for meat packaging, antimicrobial wipes and surfaces. EXAMPLES Materials and Methods The following fiber-based materials were used in the following Examples. Woven and knit fabrics were also tested as outlined in the Examples. 1. Poly(ethylene terephthalate) (“2GT”) fiber, knit fabric and microfiber woven fabric, from E. I. du Pont de Nemours and Company (Wilmington, Del.). 2. Sorona® poly(trimethylene terephthalate) (“3GT”) yarn, 70 denier, 34 filament, round cross-section, made by E. I. du Pont de Nemours and Company (Wilmington, Del.). The chitosan materials used in this study were obtained as commercially available from Primex Ingredients ASA, Norway under the trademark Chitoclear® chitosan and were used as purchased. All Examples demonstrate the use of chitosan salt, i.e., chitosan dissolved in acetic acid as the chitosan agent of the invention. Treated articles were tested for antimicrobial properties by the Shake Flask Test for Antimicrobial Testing of Materials, as follows: 1. A single, isolated colony from a bacterial or yeast agar plate culture was inoculated in 15–25 ml of Trypticase Soy Broth (TSB) in a sterile flask. It was incubated at 25–37° C. (using optimal growth temperature for the specific microbe) for 16–24 hours with or without shaking (selecting appropriate aeration of the specific strain). For filamentous fungi, sporulating cultures were prepared on agar plates. 2. The overnight bacterial or yeast culture was diluted into sterile phosphate buffer (see below) at pH 6.0 to 7.0 to obtain approximately 10 5 colony forming units per ml (cfu/ml). The total volume of phosphate buffer needed was 50 ml×number of test flasks (including controls). For filamentous fungi, spore suspensions at 10 5 spores/ml were prepared. Spore suspensions were prepared by gently resuspending spores from an agar plate culture that had been flooded with sterile saline or phosphate buffer. To obtain initial inoculum counts, final dilutions (prepared in phosphate buffer) of 10 −4 and 10 −3 were plated onto Trypticase Soy Agar (TSA) plates in duplicate. Plates were incubated at 25–37° C. overnight. 3. 50 ml of inoculated phosphate buffer was transferred into each sterile test flask containing 0.5 g of material to be tested. Also, control flasks of inoculated phosphate buffer and uninoculated phosphate buffer with no test materials were prepared. 4. All flasks were placed on a wrist-action shaker and incubated with vigorous shaking at room temperature. All flasks were sampled periodically and appropriate dilutions were plated onto TSA plates. The TSA plates were incubated at 25–37° C. for 16–48 hours and colonies were then counted. 5. Colony counts were reported as the number of Colony Forming Units per ml (cfu/ml). 6. The activity constant, At value, was calculated as follows: Δt=C−B, where Δt is the activity constant for contact time t, C is the mean log 10 density of microbes in flasks of untreated control materials after X hours of incubation, and B is the mean log 10 density of microbes in flasks of treated materials after X hours of incubation. Δt was typically calculated at 4, 6, or 24 hours and may be expressed as Δt X . Stock phosphate buffer: Monobasic Potassium Phosphate 22.4 g Dibasic Potassium Phosphate 56.0 g Deionized Water volume increased to 1000 ml The pH of the phosphate buffer was adjusted to pH 6.0 to 7.0 with either NaOH or HCl. The stock phosphate buffer was filtered, sterilized, and stored at 4° C. until use. The working phosphate buffer was prepared by diluting 1 ml of stock phosphate buffer in 800 ml of sterile deionized water. Example 1 Preparation of Chitosan Grafted 2GT and 3GT Knit Standard Polyester Fabrics Polyester fabrics (8 inch×9 inch; 3GT fabric weighing 21.8 g, 2GT fabric weighing 19.5 g) were soaked in 10% aqueous sodium hydroxide solution and gently shaken for 90 min. Each was then washed with water and soaked in 1 M aqueous hydrochloric acid solution for 30 min, washed with deionized water and dried in air for 1 h. Each was then immersed in 2 weight % aqueous chitosan solution (mol. wt. 75,000,) containing 1.5% acetic acid for 30 min, The chitosan used in Example 1 was food grade Chitoclear® chitosan (Primex Ingredients ASA, Norway). The degree of N-deacetylation of this sample was over 90% and this was ascertained by proton and carbon 13 NMR spectroscopy. The molecular weight of this sample was estimated using standard relative viscosity measurements as reported in the literature. The excess chitosan was allowed to drip, air dried for an hour and then dried at 85° C. for 16 h under nitrogen atmosphere. The weights of the chitosan-grafted fabrics were: 3GT, 24.06 g; 2GT, 21.32 g. The fabrics were then washed with water and dried at 80° C. for 16 h to give a 3GT sample weighing 23.3 g and a 2GT sample weighing 20.6 g (6.8 and 5.6% chitosan incorporation, respectively). These fabrics were tested for their antimicrobial efficacy as described above. FIG. 1 shows the antimicrobial effect of chitosan grafted on 3GT knit fabric vs. Listeria monocytogenes ATCC 15313; the 3GT control is untreated fabric. FIG. 2 shows the antimicrobial effect of chitosan grafted on 2GT knit fabric vs. Klebsiella pneumoniae ATCC 4352; the 2GT control is untreated fabric. FIG. 3 shows the antimicrobial effect of chitosan grafted on 2GT knit fabric vs. Candida albicans ATCC 10231. FIG. 4 shows the antimicrobial effect of chitosan grafted on 3GT woven fabric vs. Staphylococcus aureus ATCC 6538. Chitosan grafted onto 2GT and 3GT polyester fabrics demonstrated at least a 3-log reduction of the following microorganisms in 4–6 h: Escherichia coli ATCC 25922 Escherichia coli ATCC 49106 (enterotoxigenic/enterohemorrhagic) Escherichia coli O157:H7 (enterotoxigenic/enterohemorrhagic) Salmonella cholerasuis ATCC 9239 Staphylococcus aureus ATCC 6538 Bacillus subtilis ATCC 6633 Enterococcus faecalis ATCC 29212 Klebsiella pneumoniae ATCC 4352 Listeria monocytogenes ATCC 15313 Listeria welshimeri ATCC 35897 Pseudomonas aeruginosa ATCC 27853 Candida albicans ATCC 10231 Acinetobacter sp. ATCC 14291 Micrococcus luteus ATCC 4698 Staphylococcus cohnii ATCC 49330 Staphylococcus hominus ATCC 27844 Example 2 Grafting of Chitosan Samples of Varying Molecular Weight onto 2GT Fabrics and the Evaluation of the Resulting Antimicrobial Properties Chitosan samples with degree of de-N-acetylation of over 80% and mol. wt. in the range of 950,000 (Pfansteihl, U.S.A.), 630,000 (Sigma Chemical Company, U.S.A.), 290,000 (Kitomer, Canada), 104,000 (Chitoclear®, industrial grade, Primex Ingredients ASA, Norway), 83,000 (Chitoclear®, industrial grade, Primex Ingredients ASA, Norway), 74,000 (Chitoclear®, food grade, Primex Ingredients ASA, Norway), 39,000 (Chitoclear®, food grade, Primex Ingredients ASA, Norway), and 33,000 (Chitoclear®, food grade, Primex Ingredients ASA, Norway) were grafted onto polyester fabrics in order to evaluate the effect of chitosan molecular weight on the antimicrobial activity. A 1% solution of each commercial chitosan in 0.75% aqueous acetic acid was used in the grafting procedure as described in Example 1. As shown in FIG. 5 (2GT; E. coli ATCC 25922) and FIG. 6 (2GT; Staphylococcus aureus ATCC 29213), the process of this invention is operable with chitosans of a wide range of molecular weights. Example 3 Preparation of Chitosan Grafted Fabrics Treated With Antimicrobial Salts Chitosan grafted 3GT woven fabric (22.8 g), prepared according to the procedure of Example 1 was soaked in 2% aqueous silver nitrate solution for 30 min, extensively washed with water, and dried at 37° C. for 16 h. Weight of the resultant fabric was 23.0 g. Similarly, chitosan grafted 3GT knit fabric (23.1 g), prepared according to the procedure of Example 1 was treated with 2% copper sulfate solution as described above to obtained copper doped fabric, (23.7 g). As indicated by the results obtained, metal doping of chitosan-grafted polyester may be used to enhance antimicrobial activity. Silver nitrate ( FIG. 7 ), copper sulfate ( FIG. 8 ) or, by a similar procedure, zinc sulfate were used successfully as metal dopes. FIG. 7 demonstrates 3GT fabrics prepared with grafted chitosan with or without a silver nitrate dope vs. Salmonella cholerasuis ATCC 9239. FIG. 8 demonstrates 3GT fabrics prepared with grafted chitosan with or without a copper sulfate dope vs. E. coli O157:H7. Chitosan grafted onto 2GT and 3GT polyester, followed by doping with metals has demonstrated at least a 3-log reduction of the following microorganisms, which are known to be more resistant to antimicrobials, in 4–6 h: Escherichia coli ATCC 49106 (enterotoxigenic/enterohemorrhagic) Escherichia coli O157: H7 (enterotoxigenic/enterohemorrhagic) Salmonella cholerasuis ATCC 9239 Example 4 Preparation of Chitosan Grafted Fabrics After Treated With Various Concentrations of Silver Nitrate Solution 2GT knit fabrics in the form of (five) socks were soaked in water, the excess water drained, and then treated with 40% aqueous sodium hydroxide for 2 min. These socks were then extensively washed with water and soaked in 1M aqueous hydrochloric acid for 2 min, then washed with water. This was followed by immersing the socks in aqueous 1% chitosan (Chitoclear®, food grade, mol. wt. 74,000, Primex Ingredients ASA, Norway) solution containing 0.75% acetic acid for 2 min, then excess solution allowed to drain followed by drying the socks at 85° C. for 16 h under nitrogen. These dried samples were washed again with water and re-dried. Four samples were, respectively, treated with aqueous 0.5%, 0.25%, 0.125%, and 0.0625% silver nitrate solution for 2 min., washed with water and dried at 45 C. for 16 h. The antimicrobial activity of these 4 samples and the “chitosan-only” control were then evaluated. FIG. 9 shows the antimicrobial effect of these 5 samples vs. Staphylococcus aureus ATCC 6538. Even the lowest concentration of silver nitrate (0.0625%) is very efficacious against the microbe Staphylococcus aureus ATCC 6538 and, as shown in FIG. 10 , just 0.01% silver nitrate dope was efficacious against microbes that can only be killed with chitosan-silver, such as E. coli O157:H7. It is postulated that the low concentration of silver works in synergy with the chitosan to achieve this level of efficacy. Example 5 Preparation of Chitosan Grafted Fabrics Employing Various Times of Chitosan Treatment With and Without 0.1% Silver Nitrate Post Treatment Samples of 2GT fibers were hydrolyzed and treated with 2% chitosan by the procedure of Example 4 except that the chitosan treatment time was 0.5, 1 or 2 minutes, respectively. Portions of each of these three samples were then treated with a 0.1% silver nitrate solution as in Example 4. FIG. 10 shows the antimicrobial effect of chitosan grafted on 2GT fabrics after these various hydrolysis times with and without the 0.1% silver nitrate post treatment vs. E. coli O157:H7. Example 6 Wash Testing of Chitosan Grafted 3GT Fabrics (With and Without Silver Nitrate Post-Treatment) Samples of 3GT chitosan grafted fabrics, with and without silver nitrate treatment (3GT samples prepared in Example 3 and Example 1, respectively), were subjected to five AATCC RA 88 “C” wash cycles. Table 1 below shows the results of an E. coli ATCC 25922 shake flask test on these washed 3GT fabrics. The Δt is the log reduction between the inoculum control and the test material. As shown in Table 1, all chitosan and chitosan+silver-treated fabrics reduced the viable population of E. coli ATCC 25922 by at least 3 logs after 4 h of exposure. TABLE 1 3GT woven fabrics prepared with grafted chitosan with and without a silver nitrate post treatment vs. E. coli ATCC 25922. Fabric Δt after 1 h Δt after 4 h 3GT Control, unwashed 0.000 0.000 3GT Control, washed 0.267 0.160 3GT + Chitosan, unwashed 4.869 5.415 3GT + Chitosan, washed 2.313 3.813 3GT + Chitosan + Ag, unwashed 5.568 5.415 3GT + Chitosan + Ag, washed 5.568 5.415 Example 7 Testing of Antimicrobial Activity of Free Chitosan, Chitosan Grafted 2GT and Silver Nitrate Post-Treated Chitosan Grafted 2GT Two pieces of scoured socks (5.56 g and 5.9 g respectively) of 2GT polyester fabrics were grafted with 2% chitosan solution as described in Example 1 to generate chitosan grafted fabrics (weight after grafting was 6.2 g and 6.6 g, respectively). This latter piece of fabric (6.6 g) was then soaked with 0.5% silver nitrate solution, washed with water and dried at 37° C. for 16 h. Weight of the dried fabric was 6.6 g. For comparative purposes, free chitosan powder was tested as is in the shake flask test. FIG. 11 shows the antimicrobial activity of free chitosan, grafted chitosan and silver nitrate-treated grafted chitosan vs. Staphylococcus aureus ATCC 6538. Free chitosan demonstrates lower antimicrobial activity, which is more characteristic of a bacteriostat, compared to chitosan grafted onto polyester with or without silver nitrate post treatment. Example 8 Multi-layer Grafting of 2GT Fabrics With Chitosan and Polyacrylic Acid Four 2GT knit fabrics (samples A–D, 19.5, 18.8,19.5, 19.7 g, respectively) were grafted with chitosan as described in Example 1. Weight of the products A–D were 21.3, 20.4, 21.2, and 21.1 g, respectively. Fabric samples A and B were dipped in 2% polyacrylic acid solution for 30 min, air dried and washed with water and then dried at 80° C. to give chitosan polyacrylic acid coated fabrics A′ (21.5 g) and B′ (20.6 g). Part of fabric A′ (10.3 g) was treated again with 2% chitosan solution and dried at 85° C. for 16 h followed by washing with water and dried to give A″ (10.5 g). Another part of A′ (11.2 g) was dipped in 2% silver nitrate solution for 30 min, washed with water and dried at 37° C. for 16 h. to give A′″. Weight of A′″ was 11.02 g. FIG. 12 shows the antimicrobial activity of 2GT+chitosan (A); 2GT+chitosan+polyacrylic acid (A″); 2GT+chitosan+polyacrylic acid+chitosan (A″), and 2GT+chitosan+polyacrylic acid;+silver nitrate (A′″) and three various controls vs. E. coli 25922. Example 9 Chitosan Grafted Fibers Made in Commercial Prototype Equipment The chitosan chemistry described in the above examples can be applied to fibers as well as fabrics using standard fiber processing equipment. The preparation of antimicrobial fibers by performing the caustic hydrolysis, acidification, and chitosan grafting steps in a package dyer, as well as by performing the caustic hydrolysis and acidification in a package dyer and the chitosan grafting step in a single-end sizer machine has been demonstrated. FIG. 13 shows antimicrobial performance of 2GT fiber with grafted chitosan applied by processing in a package dyer vs. E. coli ATCC 25922. FIG. 14 shows the antimicrobial performance of 2GT fiber with grafted chitosan applied by processing in a package dyer and single-end sizer vs. E. coli ATCC 25922. Example 10 Chitosan-Treated Bicomponent Fiber: 2GT/Lycra® Blend Fibers of a Lycra® spandex/2GT blend (Lycra® spandex/2GT blend fiber containing 10% 10 denier Lycra® and 90% 150 denier Dacron® polyester, made by E. I. du Pont de Nemours and Company (Wilmington, Del.)) were treated with caustic as described in Example 1. The treated fibers were then passed through a chitosan solution in a single-end sizer as in Example 9. FIG. 15 shows the antimicrobial effect of the chitosan-treated fibers versus E. coli ATCC 25922. Example 11 Chitosan Treatment of Yarns Commonly Combined with Polyester in Fabrics Cotton yarn (having a yarn count of 30/1cc, commercially available from Parkdale Mills, Inc. (Gastonia, N.C.)), Soft White® 24 acrylic yarn ( 1/24 worsted count with a 1½″ cut, 100% open end spun yarn that has been waxed, made by Amital Spinning Corporation (New Bern, N.C.)), and Tactel® nylon 66 (30 denier yarn (commercially available from E. I. du Pont de Nemours and Company, Wilmington, Del.) were treated with caustic as described in Example 1. The treated fibers were then passed through a chitosan solution in a single end sizer as in Example 9. FIG. 16 shows the antimicrobial effect of the chitosan-treated yarns versus E. coli ATCC 25922. Example 12 Chitosan-Treated Polyester/Rayon Nonwoven Fabric Sontara® wipes comprising a 1:1 polyester/rayon nonwoven blend (commercially available from E. I. du Pont de Nemours and Company. (Wilmington, Del.) were treated as in Example 1, one sample with only the caustic treatment described therein and one with the complete chitosan grafting treatment. The antimicrobial effect of the chitosan grafting treatment versus E coli ATCC 25922 is seen in FIG. 17 . Example 13 Chitosan-Treated Polyester/Cellulose Nonwoven Fabric Sontara® wipes comprising a 1:1 polyester/wood pulp nonwoven blend (commercially available from E. I. du Pont de Nemours and Company, Wilmington, Del.) were treated as in Example 1, one sample with only the caustic treatment described therein and one with the complete chitosan grafting treatment. The antimicrobial effect of the chitosan grafting treatment versus E. coli ATCC 25922 is seen in FIG. 18 . Example 14–18 (a) Preparation of Surface Primed 2GT Fibers 2GT fiber (150–200 g, 229 g) was passed at a rate of about 8 m/min through a series of solution trays containing, in turn, 10% aqueous sodium hydroxide, 1.0 M aqueous hydrochloric acid, and water. Excess solution was then stripped from the fiber with a sponge. The fiber was then dried by wrapping around a drum heated to about 130° C. The fiber was then wound using a tension winder followed by heat setting the fiber at 160° C. by wrapping around a heated roller at that temperature and winding at a speed at 60 m/min. Yield of the fiber was 218.7 g, a loss of 4.5 weight percent. This procedure demonstrates the hydrolysis conditions that cause weight loss of the fiber. The process resulted in the formation of carboxyl groups on the surface of the fiber as evidenced from the dying of the fiber with a blue dye specific for acidic groups. (b) Preparation of 2GT Chitosan-Treated Fiber and Fabric 2GT fiber (150–200 g) was passed at a rate of about 8 m/min through a series of solution trays containing, in turn, 10% aqueous sodium hydroxide, 1.0 M aqueous hydrochloric acid, water, and a solution of chitosan (Chitoclear®, Primex Ingredients, Norway) in 1% aqueous acetic acid. The concentration of chitosan varied from 0.25 to 2 weight percent, as shown in Table 1. Excess solution was then stripped from the fiber with a sponge. The fiber was dried by wrapping around a drum heated to about 130° C. The fiber was then wound using a tension winder followed by heat setting of the fiber at 160° C. by wrapping around a heated roller at that temperature and winding at a speed at 60 m/min. In each case, the chitosan-treated fiber was tested with Orange II dye, and the orange color indicated chitosan was present on the surface of the fiber. A portion of fiber that had been treated with a 2% chitosan solution was made into a fabric and dyed with Orange II dye. The intense orange color indicated that chitosan was present at the surface of the fabric. TABLE 2 Chitosan Initial Final Weight Concentration Example Weight (g) Weight (g) Change (%) (weight %) Surface 229 218.7 −4.5 0 primed only −4.5 14 207 231 11.6 2 15 141 154 9.2 1.5 16 165 174 5.5 1 17 119 133 11.8 0.5 18 216 237 9.7 0.25 Example 20 Preparation of Antimicrobial Chitosan-2GT/3GT Fibers 2GT/3GT bicomponent fiber from E. I. du Pont de Nemours and Company (Wilmington, Del.) was passed at a rate of about 8 m/min through a series of solution trays containing, in turn, 10% aqueous sodium hydroxide, 1.0 M aqueous hydrochloric acid, water, and a solution of 0.25% chitosan (Chitoclear®, Primex Ingredients ASA, Norway) in 1% aqueous acetic acid. This was followed by stripping the excess solution in the fiber with a sponge. The fiber was dried by wrapping around a drum heated to about 130° C. The fiber was then wound using a tension winder followed by heat setting of the fiber at 160° C. by wrapping around a heated roller at that temperature and winding at a speed at 60 m/min. Two samples were taken from different part of the fiber and submitted for antimicrobial evaluation. The antimicrobial effect of the chitosan grafting treatment versus E coli ATCC 25922 is seen in FIG. 19 .

This invention relates to antimicrobial polyester-containing articles and methodology for the preparation of antimicrobial polyester-containing articles utilizing chitosan and chitosan-metal complexes as the antimicrobial agent.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This Continuation application claims the benefit of U.S. Ser. No. 14/881,932 filed Oct. 13, 2015, which is a continuation application which claims the benefit of U.S. Ser. No. 14/591,372 filed Jan. 7, 2015, now U.S. Pat. No. 9,187,506, which is a Non-Provisional application which claims the benefit of Provisional application U.S. Ser. No. 61/925,405 filed Jan. 9, 2014, now expired, hereby incorporated by reference in their entireties. BACKGROUND OF THE INVENTION [0002] The disclosure generally relates to compounds of formula I, including their salts, as well as compositions and methods of using the compounds. The compounds are ligands for the NR2B NMDA receptor and may be useful for the treatment of various disorders of the central nervous system. [0003] N-Methyl-D-aspartate (NMDA) receptors are ion channels which are gated by the binding of glutamate, an excitatory neurotransmitter in the central nervous system. They are thought to play a key role in the development of a number of neurological diseases, including depression, neuropathic pain, Alzheimer's disease, and Parkinson's disease. Functional NMDA receptors are tetrameric structures primarily composed of two NR1 and two NR2 subunits. The NR2 subunit is further subdivided into four individual subtypes: NR2A, NR2B, NR2C, and NR2D, which are differentially distributed throughout the brain. Antagonists or allosteric modulators of NMDA receptors, in particular NR2B subunit-containing channels, have been investigated as therapeutic agents for the treatment of major depressive disorder (G. Sanacora, 2008, Nature Rev. Drug Disc. 7: 426-437). [0004] The NR2B receptor contains additional ligand binding sites in addition to that for glutamate. Non-selective NMDA antagonists such as Ketamine are pore blockers, interfering with the transport of Ca ++ through the channel. Ketamine has demonstrated rapid and enduring antidepressant properties in human clinical trials as an i.v. drug. Additionally, efficacy was maintained with repeated, intermittent infusions of Ketamine (Zarate et al., 2006, Arch. Gen. Psychiatry 63: 856-864). This class of drugs, though, has limited therapeutic value because of its CNS side effects, including dissociative effects. [0005] An allosteric, non-competitive binding site has also been identified in the N-terminal domain of NR2B. Agents which bind selectively at this site, such as Traxoprodil, exhibited a sustained antidepressant response and improved side effect profile in human clinical trials as an i.v. drug (Preskorn et al., 2008, J. Clin. Psychopharmacol., 28: 631-637, and F. S. Menniti, et al., 1998, CNS Drug Reviews, 4, 4, 307-322). However, development of drugs from this class has been hindered by low bioavailability, poor pharmacokinetics, and lack of selectivity against other pharmacological targets including the hERG ion channel. Blockade of the hERG ion channel can lead to cardiac arrythmias, including the potentially fatal Torsades de pointe, thus selectivity against this channel is critical. Thus, in the treatment of major depressive disorder, there remains an unmet clinical need for the development of effective NR2B-selective negative allosteric modulators which have a favorable tolerability profile. [0006] NR2B receptor antagonists have been disclosed in PCT publication WO 2009/006437. [0007] The invention provides technical advantages, for example, the compounds are novel and are ligands for the NR2B receptor and may be useful for the treatment of various disorders of the central nervous system. Additionally, the compounds provide advantages for pharmaceutical uses, for example, with regard to one or more of their mechanism of action, binding, inhibition efficacy, target selectivity, solubility, safety profiles, or bioavailability. DESCRIPTION OF THE INVENTION [0008] One aspect of the invention is a compound of formula I [0000] [0000] where: Ar 1 is phenyl or indanyl and is substituted with 0-3 substituents selected from cyano, halo, alkyl, haloalkyl, and haloalkoxy; Ar 2 is phenyl substituted with 1 OR substituent and also substituted with 0-3 substituents selected from cyano, halo, alkyl, haloalkyl, and haloalkoxy; R is a prodrug moiety selected from the group consisting of alkyl esters, amino acid esters, alkoxy esters, phosphonic acids, phosphonic alkyl esters, alkoxyphosphononate acid, alkoxyphosphonate alkyl esters, alkyl carabamates, amino acid carbamates, alkyl phosporamidates, aryl phosphoramidates, and sulfamates; X is a bond or C 1 -C 3 alkylene; n is 1 or 2; and ring A is azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, homopiperidinyl, or homopiperazinyl and is substituted with 0-4 substituents selected from halo, alkyl, hydroxy, or alkoxy; or a pharmaceutically acceptable salt thereof. [0009] Another aspect of the invention is a compound of the formula [0000] [0000] where R is a prodrug moiety selected from the group consisting of alkyl esters, amino acid esters, alkoxy esters, phosphonic acids, phosphonic alkyl esters, alkoxyphosphononate acid, alkoxyphosphonate alkyl esters, alkyl carabamates, amino acid carbamates, alkyl phosporamidates, aryl phosphoramidates, and sulfamates; or a pharmaceutically acceptable salt thereof. Synthetic Methods [0010] Compounds of Formula I may be made by methods known in the art including those described below and including variations within the skill of the art. Some reagents and intermediates are known in the art. Other reagents and intermediates can be made by methods known in the art using readily available materials. The variables (e.g. numbered “R” substituents) used to describe the synthesis of the compounds are intended only to illustrate how to make the compounds and are not to be confused with variables used in the claims or in other sections of the specification. The following methods are for illustrative purposes and are not intended to limit the scope of the invention. The schemes encompass reasonable variations known in the art. [0011] Scheme 1 shows an effective synthesis of example 1, (R)-3-((3S,4S)-3-fluoro-4-(4-hydroxyphenyl)piperidin-1-yl)-1-(4-methylbenzyl)pyrrolidin-2-one. Hydroxylactam 1 is available commercially in optically pure form. It can be protected and N-alkylated to form lactam 4. Deprotection and activation of he hydroxyl group with methanesulfonylchloride leads to the lactam 5. Separately, compound 6 can be prepared by the Suzuki coupling reaction between commercial 4-benzyloxybromobenzene and commercial tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate. Treatment of 6 with in-situ prepared borane followed by oxidation results in formation of the trans racemic alcohol 7. The alcohol 7 can be separated in to the individual enantiomers, and the phenol can be unmasked using hydrogenation under standard conditions to the prepare the substituted phenol 8. Fluorination with de-oxofluor reagent provides selectively the trans aryl fluoride 9, and deprotection of the Boc group with hydrochloric acid provides the piperidine as the hydrochloride salt. Simple extraction under basic conditions provides the piperidine 10 as the freebase. Careful reaction of the piperidine 10 with the lactam 5 under mildly basic conditions provides (R)-3-((3S,4S)-3-fluoro-4-(4-hydroxyphenyl)piperidin-1-yl)-1-(4-methylbenzyl)pyrrolidin-2-one, the title compound of example 1. [0000] [0012] The compound of example 1 can be transformed into a variety of prodrugs using methods known in the art. Thus, according to scheme 2, treatment of the phenol with POCl 3 , pyridine, and DMAP followed by aqueous hydrolysis provides example 2, the dihydrogen phosphate ester of example 1. [0000] [0013] Similarly, reaction of the compound of example 1 with a Boc-protected amino acid using a variety of methods known in the art, but preferably using dicyclohexylcarbodiimide and 4-dimethylaminopyridine provides the ester 11. Clevage of the Boc group in acid, preferably HCl, provides the esters which include the compounds of examples 3 and 4. [0000] [0014] In a similar manner, Boc-protected aspartic acid tert-butyl ester (12) can be coupled through the unprotected sidechain to the compound of example 1 to provide the ester 13. Deprotection with HCl again provides the compound of example 5. [0000] DESCRIPTION OF SPECIFIC EMBODIMENTS [0015] Abbreviations used in the schemes generally follow conventions used in the art. Chemical abbreviations used in the specification and examples are defined as follows: “NaHMDS” for sodium bis(trimethylsilyl)amide; “DMF” for N,N-dimethylformamide; “MeOH” for methanol; “NBS” for N-bromosuccinimide; “Ar” for aryl; “TFA” for trifluoroacetic acid; “LAH” for lithium aluminum hydride; “BOC” for t-butoxycarbonyl, “DMSO” for dimethylsulfoxide; “h” for hours; “EtOAc” for ethyl acetate; “THF” for tetrahydrofuran; “EDTA” for ethylenediaminetetraacetic acid; “Et 2 O” for diethyl ether; “DMAP” for 4-dimethylaminopyridine; “DCE” for 1,2-dichloroethane; “ACN” for acetonitrile; “DME” for 1,2-dimethoxyethane; “HOBt” for 1-hydroxybenzotriazole hydrate; “DIEA” for diisopropylethylamine, “Nf” for CF 3 (CF 2 ) 3 SO 2 —; and “TMOF” for trimethylorthoformate. [0016] Abbreviations as used herein, are defined as follows: “1×” for once, “2×” for twice, “3×” for thrice, “° C.” for degrees Celsius, “eq” for equivalent or equivalents, “g” for gram or grams, “mg” for milligram or milligrams, “L” for liter or liters, “mL” for milliliter or milliliters, “4” for microliter or microliters, “N” for normal, “M” for molar, “mmol” for millimole or millimoles, “min” for minute or minutes, “h” for hour or hours, “rt” for room temperature, “RT” for retention time, “atm” for atmosphere, “psi” for pounds per square inch, “conc.” for concentrate, “sat” or “satd.” for saturated, “MW” for molecular weight, “mp” for melting point, “ee” for enantiomeric excess, “MS” or “Mass Spec” for mass spectrometry, “ESI” for electrospray ionization mass spectroscopy, “HR” for high resolution, “HRMS” for high resolution mass spectrometry, “LCMS” for liquid chromatography mass spectrometry, “HPLC” for high pressure liquid chromatography, “RP HPLC” for reverse phase HPLC, “DCM” for dichloromethane, “TLC” or “tlc” for thin layer chromatography, “SFC” for supercritical fluid chromatography, “NMR” for nuclear magnetic resonance spectroscopy, “ 1 H” for proton, “□” for delta, “s” for singlet, “d” for doublet, “t” for triplet, “q” for quartet, “m” for multiplet, “br” for broad, “Hz” for hertz, and “R”, “S”, “E”, and “Z” are stereochemical designations familiar to one skilled in the art. [0017] LC/MS data were acquired using the following conditions: [0018] Conditions A: Ascentis C18 50×2.1 mm, 2.7 μm column using a 1 mL/min flowrate gradient of 0-100% B over 1.7 minutes followed by 1.3 minutes at 100% B. Solvent A: 10 mM NH4COOH in water:acetonitrile (98:2); solvent B=10 mM NH4COOH in water:acetonitrile (2:98). [0019] Conditions B: Phenomenex C18 2.0×50 mm, 5 μm column using a 0.8 mL/min flowrate gradient of 0-100% B over 4 minutes. Solvent A=10% MeOH/90% water/0.1% TFA, Solvent B=90% MeOH/10% water/0.1% TFA. Synthesis of Intermediates Intermediate A. tert-Butyl 4-(4-(benzyloxy)phenyl)-5,6-dihydropyridine-1(2H)-carboxylate [0020] [0021] A solution of commercial 1-(benzyloxy)-4-bromobenzene (104 g, 395 mmol) and commercial tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate (147 g, 474 mmol) in 1100 mL of acetonitrile was purged with nitrogen for 2 min. Water (1100 mL) was added, followed by sodium carbonate (126 g, 1186 mmol) and tetrakis(triphenylphosphine)palladium (27.4 g, 23.7 mmol). The reaction mixture was purged with nitrogen for 5 min, and then heated to 90° C. and stirred for 16 h. The reaction mixture was then allowed to cool to rt and diluted with 1 L of ethyl acetate. The layers were separated, and the aqueous layer was extracted with two additional 250 mL portions of ethyl acetate. The organic layers were combined, washed with 200 mL of brine, dried over sodium sulfate, and evaporated in vacuo to provide an off-white solid. The product was purified by silica gel chromatography eluting with 6% ethyl acetate in petroleum ether to provide 129 g (88%) of the desired product. LC/MS RT (conditions A)=2.732 min, (M−H)+=364.0. 1 H NMR (300 MHz, chloroform-d) δ 7.49-7.30 (m, 5H), 7.27 (d, J=10.7 Hz, 2H), 6.99-6.87 (m, 2H), 6.03-5.87 (m, 1H), 5.07 (s, 2H), 4.05 (d, J=2.6 Hz, 2H), 3.62 (t, J=5.7 Hz, 2H), 2.49 (br. s., 2H), 1.49 (s, 9H). Intermediate B. (+/−)-rel-(3S,4S)-tert-Butyl 4-(4-(benzyloxy)phenyl)-3-hydroxypiperidine-1-carboxylate [0022] [0023] Sodium borohydride (15.5 g, 410 mmol) was dissolved in THF, and the solution was chilled to 0° C. Boron trifluoride etherate (52.3 mL, 424 mmol) was added to the solution and the mixture was allowed to warm to rt and stirred for 30 min. Then a solution of tert-butyl 4-(4-(benzyloxy)phenyl)-5,6-dihydropyridine-1(2H)-carboxylate (50 g, 137 mmol, intermediate A) in 500 mL of THF was added and the reaction mixture was stirred for 2 h at rt. A 100 mL portion of water was then added slowly to the mixture (Caution: effervescence is observed). The mixture was diluted with 100 mL of ethanol, and sodium hydroxide (228 mL, 10% solution in water, 0.684 mol) and hydrogen peroxide (20.5 mL, 0.684 mol) were added. The reaction mixture was heated to reflux temperature and stirred for 16 h. The mixture was cooled to 10° C. and diluted with 1 L of DCM. Then the pH was adjusted to 7 with 1.5 L of 1.5 N HCl. The layers were then separated, and the aqueous layer was extracted with an addition two 500 mL portions of DCM. The organic layers were combined, washed with 2×1 L of water and 200 mL of brine, dried over sodium sulfate, and evaporated in vacuo to provide an off-white solid. The solid was triturated with 500 mL of pet ether, and isolated by filtration to yield 46.5 grams of product (88%, 99.0% purity by HPLC). LC/MS RT (conditions A)=2.372 min, (M+H) + =382.0. 1 H NMR (400 MHz, DMSO-d 6 ) δ 7.47-7.42 (m, 2H), 7.42-7.36 (m, 2H), 7.36-7.28 (m, 1H), 7.14 (d, J=9.0 Hz, 2H), 6.92 (d, J=9.0 Hz, 2H), 5.07 (s, 2H), 4.74 (d, J=5.5 Hz, 1H), 4.10 (br. s., 1H), 3.94 (br. s., 1H), 3.46-3.35 (m, 1H), 2.47-2.31 (m, 2H), 1.70-1.61 (m, 1H), 1.55-1.45 (m, 2H), 1.42 (s, 9H). Intermediate C. (3S,4S)-tert-Butyl 4-(4-(benzyloxy)phenyl)-3-hydroxypiperidine-1-carboxylate [0024] [0025] Racemic rel-(3S,4S)-tert-butyl 4-(4-(benzyloxy)phenyl)-3-hydroxypiperidine-1-carboxylate (112 g, intermediate B) was separated into the individual enantiomers using preparative supercritical fluid chromatography under the following conditions: A Thar SFC-250 instrument was utilized with a Lux-Cellulose-2 (250×21 mm), 5 μn column eluting with 60% CO 2 and 40% of a solution of 0.3% diethylamine in methanol at a flow rate of 100.0 g/min. Sample was injected at 74 mg/mL. Analytical SFC was carried out on Lux-Cellulose-2 (250×4.6 mm), 5 μm column eluting with 55% CO 2 and 45% of a solution of 0.3% diethylamine in methanol at a flow rate of 3.0 g/min. The recovery was 50.0 g of peak 1 with a retention time of 2.49 minutes, which corresponds to the desired (3S,4S)-tert-butyl 4-(4-(benzyloxy)phenyl)-3-hydroxypiperidine-1-carboxylate. Analytical data matched those from the racemate. Intermediate D. (3S,4S)-tert-Butyl 3-hydroxy-4-(4-hydroxyphenyl)piperidine-1-carboxylate [0026] [0027] A solution of (3S,4S)-tert-butyl 4-(4-(benzyloxy)phenyl)-3-hydroxypiperidine-1-carboxylate (26 g, 67.8 mmol, intermediate C) in 260 mL of methanol was treated with 1.6 grams of 10% palladium on carbon (13.6 mmol) in a pressure bottle. Hydrogen at 50 psi was introduced, and the reaction mixture was stirred for 16 h. The mixture ws filtered through celite and concentrated to a crude product (18.9 g, 64.4 mmol) which was sufficiently pure to carry forward without further purification. LC/MS RT (conditions B)=2.970 min, (M+H with loss of t-butyl) + =238.0. 1 H NMR (400 MHz, DMSO-d 6 ) δ 9.10 (br. s., 1H), 7.01 (d, J=8.5 Hz, 2H), 6.65 (s, 2H), 4.70 (d, J=5.0 Hz, 1H), 4.09 (br. s., 1H), 3.93 (br. s., 1H), 3.17 (s, 2H), 2.79-2.63 (m, 1H), 2.34 (br. s., 1H), 1.68-1.57 (m, 1H), 1.44 (br. s., 1H), 1.42 (s, 9H). Intermediate E. (3S,4S)-tert-Butyl 3-fluoro-4-(4-hydroxyphenyl)piperidine-1-carboxylate [0028] [0029] A solution of (3S,4S)-tert-butyl 3-hydroxy-4-(4-hydroxyphenyl)piperidine-1-carboxylate (15.5 g, 61.4 mmol, intermediate D) in 270 mL of acteonitrile was chilled to 0° C. To the stirred solution was added bis(2-methoxyethyl)aminosulfur trifluoride 50% solution in toluene (Deoxo-fluor, 58.4 mL, 159 mmol) dropwise via addition funnel over 65 min. After the addition, the reaction mixture was stirred for 30 min at 0° C. and then allowed to come to rt and stirred for an additional 2 h. A saturated ammonium chloride solution (150 mL) was then added, and the mixture was extracted with two 150 mL portions of DCM. The organic layers were combined, dried over sodium sulfate, and concentrated to afford the crude product. The product was purified by silica gel chromatography (1.5 kg of silica) eluting with a gradient of 0-15% acetone in hexanes to afford 11.9 g (75%) of the desired (3S,4S)-tert-butyl 3-fluoro-4-(4-hydroxyphenyl)piperidine-1-carboxylate. LC/MS RT (conditions B)=3.295 min, (M+H with loss of t-butyl and elimination of fluorine) + =220.0. 1 H NMR (400 MHz, chloroform-d) δ 7.15 (d, J=8.6 Hz, 2H), 6.83 (dt, J=8.6, 2.0 Hz, 2H), 4.59-4.48 (m, 1H), 4.47-4.37 (m, 1H), 4.23-4.12 (m, 1H), 2.88-2.68 (m, 3H), 1.96-1.84 (m, 1H), 1.80-1.66 (m, 1H), 1.51 (s, 9H). Intermediate F. 4-((3S,4S)-3-Fluoropiperidin-4-yl)phenol [0030] [0031] A solution of (3S,4S)-tert-butyl 3-fluoro-4-(4-hydroxyphenyl)piperidine-1-carboxylate (12.0 g, 40.6 mmol, intermediate E) in anhydrous dioxane (80 mL) was treated with HCl (4 M in 1,4-dioxane, 40.6 mL, 162 mmol). The reaction mixture was allowed to stir at rt for 6 h and then evaporated in vacuo to provide the HCl salt of the desired product. Without further isolation, the HCl salt was suspended in CHCl 3 and 80 mL of a satd. NaHCO 3 solution was added. The organic layer was separated, and the aqueous layer was extracted with CHCl 3 (2×100 mL). The organic layers were combined, dried over Na 2 SO 4 and concentrated to give the title compound (7.1 g, 36.4 mmol, 90%). LC/MS RT (conditions B)=1.008 min, LC/MS (M+H) + =196.2. Intermediate G. (S)-3-((tert-Butyldimethylsilyl)oxy)pyrrolidin-2-one [0032] [0033] A stirred solution of commercial (S)-3-hydroxypyrrolidin-2-one (5 g, 49.5 mmol) in DCM (198 ml) was treated with DMAP (0.199 g, 1.632 mmol), imidazole (6.73 g, 99 mmol), and TBDMS-Cl (8.94 g, 59.3 mmol). The reaction mixture was stirred at rt for 16 h, and then was washed with a satd. NaHCO 3 solution. The organic layer was concentrated and the crude reaction product was purified by silica gel chromatography eluting with 50% ethyl acetate in petroleum ether. The desired product was isolated as a white solid (8.1 g, 76%). LC/MS (M+H) + =216.2. 1 H NMR (400 MHz, chloroform-d) δ 6.40 (br. s., 1H), 4.26 (t, J=7.8 Hz, 1H), 3.42-3.34 (m, 1H), 3.29-3.21 (m, 1H), 2.36 (dtd, J=12.7, 7.3, 3.3 Hz, 1H), 2.07-1.96 (m, 1H), 0.91 (s, 9H), 0.15 (d, J=7.0 Hz, 6H). Intermediate H. (S)-3-((tert-Butyldimethylsilyl)oxy)-1-(4-methylbenzyl)pyrrolidin-2-one [0034] [0035] (S)-3-((tert-butyldimethylsilyl)oxy)pyrrolidin-2-one (5 g, 23.22 mmol, intermediate G) was dissolved in anhydrous THF (46.4 ml) and the reaction mixture was cooled to 0° C. under a nitrogen atmosphere. Sodium hydride (1.393 g, 34.8 mmol) was then added in one portion and the reaction mixture was allowed to stir for 5 min before the dropwise addition of 1-(bromomethyl)-4-methylbenzene (5.37 g, 29.0 mmol) in anhydrous THF (46.4 ml). The reaction was allowed to stir at 0° C. for 5 min, then the cooling bath was removed and mixture was allowed to warm to rt overnight. The reaction was cautiously quenched with water (100 mL) and then extracted with ethyl acetate (3×100 mL). The combined organic layers were then washed with brine (200 mL) and dried (MgSO 4 ). Evaporation of the solvent in vacuo gave the crude product (9.6 g, oil) which was then purified by silica gel chromatography (330 g of sliica) eluting with a gradient of 0% to 20% ethyl acetate in hexanes to provide 6.53 g (88%) of the desired product. LC/MS (Conditions B), RT=4.320 min, (M+H) + =320.3. 1 H NMR (400 MHz, chloroform-d) δ 7.15 (s, 4H), 4.42 (s, 2H), 4.37 (t, J=7.6 Hz, 1H), 3.32-3.18 (m, 1H), 3.10 (dt, J=9.7, 7.5 Hz, 1H), 2.36 (s, 3H), 2.29 (dtd, J=12.6, 7.6, 3.1 Hz, 1H), 1.97-1.84 (m, 1H), 0.95 (s, 9H), 0.20 (d, J=10.3 Hz, 6H). Intermediate I. (S)-3-Hydroxy-1-(4-methylbenzyl)pyrrolidin-2-one [0036] [0037] HCl (4 M in 1,4-dioxane, 25.5 ml, 102 mmol) was added in one portion to a solution of (S)-3-((tert-butyldimethylsilyl)oxy)-1-(4-methylbenzyl)pyrrolidin-2-one (6.53 g, 20.44 mmol, intermediate H) in anhydrous DCM (20.4 mL) at rt. A slight exotherm was noted. The reaction mixture was allowed to stir at rt for 2 h and then evaporated in vacuo. The residue was taken up in DCM (100 mL) and washed with a satd. sodium bicarbonate solution (100 mL) and brine (50 mL), and then the solution was dried over MgSO 4 and concentrated to a residue. The crude product was purified by silica gel chromatography (120 g of silica) eluting with a gradient of 40% to 100% ethyl acetate in hexanes to provide 3.73 g (89%) of the desired product. LC/MS (Conditions B), RT=2.338 min, (M+H) + =206.2. 1 H NMR (400 MHz, chloroform-d) δ 7.26-7.02 (m, 4H), 4.43 (d, J=3.5 Hz, 2H), 4.41-4.37 (m, 1H), 3.66 (d, J=2.6 Hz, 1H), 3.34-3.05 (m, 2H), 2.41 (dddd, J=12.8, 8.4, 6.6, 2.2 Hz, 1H), 2.34 (s, 3H), 1.93 (dq, J=12.8, 8.8 Hz, 1H). Intermediate J. (S)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl methanesulfonate [0038] [0039] Triethylamine (0.509 ml, 3.65 mmol) was added to a cooled solution of (S)-3-hydroxy-1-(4-methylbenzyl)pyrrolidin-2-one (0.5 g, 2.436 mmol, intermediate I) in anhydrous DCM (12.18 ml) at 0° C. under a nitrogen atmosphere. Methanesulfonyl chloride (0.198 ml, 2.56 mmol) was then added dropwise and the reaction was allowed to stir at 0° C. for 15 min before quenching with a satd. sodium bicarbonate solution (10 mL). The mixture was allowed to warm to rt and the aqueous layer was separated and extracted with DCM (2×). The combined organic layers were dried over MgSO 4 and evaporated in vacuo to give a white solid (0.73 g) which was then purified by silica gel chromatography (40 g of silica) eluting with a gradient of 0% to 50% ethyl acetate in hexanes to provide 0.63 g (91%) of the desired product as a white solid. Intermediate K. (S)-3-(tert-Butyldimethylsilyloxy)-1-(4-(difluoromethyl)benzyl)pyrrolidin-2-one [0040] [0041] A 60% dispersion of sodium hydride in mineral oil (232 mg, 5.31 mmol) was added to a stirred solution of (S)-3-((tert-butyldimethylsilyl)oxy)pyrrolidin-2-one (762 mg, 3.54 mmol, intermediate G) in THF (7 mL) at 0° C. After 15 min, a solution of 1-(bromomethyl)-4-(difluoromethyl)benzene (980 mg, 4.43 mmol) in THF (7 mL) was added to the reaction mixture. The resulting mixture was stirred at room temperature for 6 h. The reaction was carefully quenched with several grams of ice pellets. The resulting mixture was extracted with EtOAc. The combined organic layers were washed with water, dried over sodium sulfate, filtered and concentrated in vacuo. The crude reaction mixture was purified using silica gel column chromatography (0-30% EtOAc/hexanes) to afford the desired product (440 mg, 35% yield) as a white solid: LCMS (M+H) + 356.3; 1 H NMR (500 MHz, chloroform-d) δ 7.49 (d, J=8.1 Hz, 2H), 7.35 (d, J=7.9 Hz, 2H), 6.65 (br. t, J=1.0 Hz, 1H), 4.56-4.44 (m, 2H), 4.38 (t, J=7.5 Hz, 1H), 3.27 (ddd, J=9.7, 8.7, 3.4 Hz, 1H), 3.13 (dt, J=9.7, 7.4 Hz, 1H), 2.36-2.27 (m, 1H), 1.98-1.90 (m, 1H), 0.96 (br. s., 9H), 0.22-0.20 (m, 3H), 0.20-0.18 (m, 3H). Intermediate L. (S)-1-(4-(Difluoromethyl)benzyl)-3-hydroxypyrrolidin-2-one [0042] [0043] A solution of 4 M HCl in dioxane (0.62 mL, 2.5 mmol) was added to a stirred solution of (S)-3-((tert-butyldimethylsilyl)oxy)-1-(4-(difluoromethyl)benzyl)pyrrolidin-2-one (440 mg, 1.24 mmol, intermediate K) in dichloromethane (1.24 mL) at rt. The reaction mixture was stirred for 2 h. The reaction mixture was concentrated in vacuo to afford the desired product (368 mg, quantitative yield): LC-MS (M+H) + 242.1. Intermediate M. (S)-1-(4-(Difluoromethyl)benzyl)-2-oxopyrrolidin-3-yl methanesulfonate [0044] [0045] Triethylamine (0.319 mL, 2.29 mmol) and methansulfonyl chloride (0.131 mL, 1.68 mmol) was added to a stirred solution of (S)-1-(4-(difluoromethyl)benzyl)-3-hydroxypyrrolidin-2-one (368 mg, 1.53 mmol, intermediate L) in dichloromethane (7.63 mL) at 0° C. The reaction mixture was stirred at 0° C. for 1 h. The resulting mixture was diluted with water and the aqueous mixture was extracted with dichloromethane. The combined organic layers were washed with 10% sodium bicarbonate solution, dried over sodium sulfate, filtered, and concentrated in vacuo. The crude material was purified using silica gel column chromatography (0-100% EtOAc). The pure fractions were combined and concentrated in vacuo to afford the desired product (322 mg, 66% yield) as a white solid: LC-MS (M+H) + 320.1; 1 H NMR (500 MHz, chloroform-d) δ 7.53 (d, J=7.9 Hz, 2H), 7.38-7.33 (m, 2H), 6.67 (br. t, J=1.0 Hz, 1H), 5.27 (dd, J=8.2, 7.5 Hz, 1H), 4.60-4.49 (m, 2H), 3.41-3.35 (m, 1H), 3.33 (s, 3H), 3.27 (dt, J=9.9, 7.3 Hz, 1H), 2.64-2.55 (m, 1H), 2.27 (ddt, J=13.9, 8.9, 7.1 Hz, 1H). Intermediate N. tert-Butyl 4-hydroxy-4-(4-methoxyphenyl)piperidine-1-carboxylate [0046] [0047] A mixture of commercial tert-butyl 4-oxopiperidine-1-carboxylate (2.0 g, 10.0 mmol) and diethyl ether (30 ml) was cooled to 0° C. To this mixture was added dropwise a solution of (4-methoxyphenyl)magnesium bromide (0.5 M in diethyl ether, 30 ml, 15 mmol). After complete addition, the reaction mixture was allowed to warm to rt and stirred for 2 h. It was then slowly quenched with 150 ml of ice cold water and then the resulting mixture was extracted with 3×150 ml of DCM. The organic layers were combined, dried, filtered, and concentrated under vacuum. The crude product was purified by silica gel column chromatography (30:70 ethyl acetate:hexane) to provide the desired product (3.0 g, 100% yield): LC-MS (ES-API): m/z 305.5 (M−H) + ; 1 H NMR (400 MHz, DMSO-d 6 ) δ 7.37 (q, J=1.0 Hz, 2H), 6.86 (q, J=1.0 Hz, 2H), 4.94 (s, 1H), 3.82 (d, J=11.5 Hz, 2H), 3.73 (s, 3H), 3.13 (br. s, 2H), 1.75 (td, J=12.9, 4.8 Hz, 2H), 1.56 (d, J=12.3 Hz, 2H), 1.41 (s, 9H). Intermediate O. 4-(4-Methoxyphenyl)-1,2,3,6-tetrahydropyridine hydrochloride [0048] [0049] A mixture of tert-butyl 4-hydroxy-4-(4-methoxyphenyl)piperidine-1-carboxylate (700 mg, 2.27 mmol, intermediate N) and HCl in dioxane (4.0 ml, 16 mmol) was stirred at rt for 3 h. The crude mass was concentrated under vacuum and the solid residue was washed with 3×10 ml of DCM to remove non-polar impurities. The desired salt was collected as a fine solid (480 mg, 93%). LCMS (ES-API) m/z 190.2 (M+H) + ; 1 H NMR (400 MHz, DMSO-d 6 ) δ 7.37 (d, J=9.0 Hz, 2H), 6.98 (d, J=9.0 Hz, 2H), 6.08-5.98 (m, 1H), 5.11 (s, 1H), 3.97 (br. s., 1H), 3.52 (s, 1H), 3.32 (s, 3H), 2.47-2.37 (m, 1H). Intermediate P. 4-(4-Methoxyphenyl)piperidine hydrochloride [0050] [0051] To a stirred solution of 4-(4-methoxyphenyl)-1,2,3,6-tetrahydropyridine, HCl (3.00 g, 13.3 mmol, intermediate 0) in methanol (20 mL) was added 10% palladium on carbon (1.4 g) and the reaction mixture was stirred at 20 psi of hydrogen for 12 h. The reaction mixture was filtered through a pad of celite, which was washed with ethyl acetate, and the combined organic fractions were concentrated to obtain a white solid (2.0 g, 70% yield): LCMS (ES-API), m/z 192.1 (M+H) + ; 1 H NMR (300 MHz, DMSO-d 6 ) δ 9.13-8.36 (m, 2H), 7.14 (d, J=8.7 Hz, 2H), 6.90 (d, J=8.7 Hz, 2H), 3.73 (s, 3H), 3.07-2.87 (m, 4H), 2.87-2.65 (m, 4H). Intermediate Q. 2,4-Dibromo-N-(4-fluorobenzyl)butanamide [0052] [0053] TEA (8.91 mL, 63.9 mmol) and 2,4-dibromobutanoyl chloride (5.07 mL, 38.4 mmol) were sequentionally added to solution of commercial (4-fluorophenyl)methanamine (4.0 g, 32.0 mmol) in diethyl ether (15 mL) at 0° C. The reaction mixture was allowed to warm to rt and stir for an additional 24 h. The reaction mixture was filtered. The solids were washed with diethyl ether. The filtrate was concentrated in vacuo to afford a crude mixture containing 2,4-dibromo-N-(4-fluorobenzyl)butanamide (8.0 g, 71% yield): LCMS (ES-API), m/z 354, 356 (M+H) + . Intermediate R. 3-Bromo-1-(4-fluorobenzyl)pyrrolidin-2-one [0054] [0055] A 60% dispersion of NaH in mineral oil (1.70 g, 42.5 mmol) was added to a stirred solution of 2,4-dibromo-N-(4-fluorobenzyl)butanamide (10.0 g, 28.3 mmol, intermediate Q) in THF (25 mL) at 0° C. The reaction mixture was allowed to warm to rt and stir for and additional 2 h. The reaction mixture was carefully quenched with ice and diluted with water. The resulting mixture was extracted with EtOAc. The combined organic layers were washed with water and then brine solution. The organic layer was over sodium sulfate, filtered, and concentrated in vacuo. The crude product was purified using silica gel column chromatography (10% EtOAc/hexanes) to afford the desired product (5.90 g, 64% yield): LCMS (ES-API), m/z 272.4, 274.3 (M+H) + ; 1 H NMR (400 MHz, DMSO-d 6 ) δ ppm 2.12-2.27 (m, 1H) 2.56-2.68 (m, 1H) 3.27 (dd, J=7.78, 3.26 Hz, 2H) 4.29-4.38 (m, 1H) 4.40-4.57 (m, 1H) 4.73 (dd, J=7.03, 3.01 Hz, 1H) 7.04-7.35 (m, 4H). Intermediate S. 1-(4-Fluorobenzyl)-3-(4-(4-methoxyphenyl)piperidin-1-yl)pyrrolidin-2-one [0056] [0057] TEA (0.768 mL, 5.51 mmol) was added to a stirred solution of 3-bromo-1-(4-fluorobenzyl)pyrrolidin-2-one (0.3 g, 1.10 mmol, intermediate R) and 4-(4-methoxyphenyl)piperidine hydrochloride (0.276 g, 1.213 mmol, intermediate P) in acetonitrile (10 mL). The reaction mixture was sealed and heated in a chemistry microwave at 100° C. for 1 h. The reaction mixture was cooled to rt and concentrated in vacuo. The residue was diluted with EtOAc. The organic mixture was washed with water and brine solution. The organic layer was dried over sodium sulfate, filtered and concentrated in vacuo to afford a crude mixture containing 1-(4-fluorobenzyl)-3-(4-(4-methoxyphenyl)piperidin-1-yl)pyrrolidin-2-one (0.35 g, 83% yield): LCMS (ES-API), m/z 383.2 (M+H) + . Example 1 (R)-3-((3S,4S)-3-fluoro-4-(4-hydroxyphenyl)piperidin-1-yl)-1-(4-methylbenzyl)pyrrolidin-2-one [0058] [0059] A solution of 4-((3S,4S)-3-fluoropiperidin-4-yl)phenol (7.10 g, 36.4 mmol, intermediate F) and DIEA (16 mL, 92 mmol) in 100 mL of acetonitrile was heated to 80° C. This solution was treated dropwise with a solution of (S)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl methanesulfonate (10.5 g, 37.0 mmol, intermediate J) in acetonitrile (80 mL) over a period of 4 hours. After the addition was completed, the reaction mixture was stirred at 80° C. for 16 h. The reaction mixture was then allowed to cool to rt, and the volume was reduced by rotary evaporation to 80 mL. A satd. NH 4 Cl solution (100 mL) was then added, and the layers were separated. The aqueous layer was extracted with DCM (2×100 mL) and the organic layers were combined, dried over Na 2 SO 4 and concentrated in vacuo to give a crude product. The crude product was purified by silica gel chromatography (750 g of silica gel) eluting with a gradient of 0% to 20% of solvent B in solvent A, where Solvent B=20% methanol/DCM and solvent A=DCM. Fractions containing the product were combined. Evaporation of the solvents gave 9.3 grams of the desired product with 97% purity by LC/MS analysis (conditions B). The product thus obtained (8.5 g) was slurried in acetone:hexane (1:5, 200 mL) and the solid product was isolated by filtration and air dried. Careful SFC analysis showed the presence of a 2.1% impurity in the product. Using a Cell4 0.46×25 cm 5 μm column and eluting with 45% methanol in CO 2 at 3 mL/min, the desired product eluted at 3.800 minutes and the undesired impurity eluted at 4.848 minutes. The product was then further purified by SFC Chromatography using a Cell4 3×25 cm 5 μm column at 150 mL/min injecting 1.5 mL of a 80 mg/mL solution. Concentration of the active fractions provided 7.82 grams (20.4 mmol, 56%) of >99.7% pure example 1 as a white powder. LC/MS (Conditions B), RT=2.512 min, (M+H) + =383.3. 19 F NMR δ −182.83. 1 H NMR (400 MHz, chloroform-d) δ 7.20-7.08 (m, 6H), 6.98-6.78 (m, 2H), 5.68 (s, 1H), 4.77-4.54 (m, 1H), 4.53-4.34 (m, 2H), 3.68 (t, J=8.8 Hz, 1H), 3.41-3.29 (m, 1H), 3.28-3.09 (m, 2H), 2.82 (d, J=10.8 Hz, 1H), 2.74-2.54 (m, 2H), 2.47 (td, J=9.9, 3.6 Hz, 1H), 2.34 (s, 3H), 2.19-1.94 (m, 2H), 1.92-1.80 (m, 2H). 13 C NMR (101 MHz, chloroform-d) δ 172.4, 154.9, 137.5, 133.3, 133.0, 129.5, 128.7, 128.3, 115.5, 92.6, 90.8, 65.0, 54.4, 54.2, 48.7, 48.0, 47.8, 46.8, 43.7, 31.7, 31.6, 21.1, 19.6. Example 2 4-((3S,4S)-3-Fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl dihydrogen phosphate [0060] [0061] To a suspension of (R)-3-((3S,4S)-3-fluoro-4-(4-hydroxyphenyl)piperidin-1-yl)-1-(4-methylbenzyl)pyrrolidin-2-one (100 mg, 0.261 mmol, example 1) in 10 mL of dichloromethane was added pyridine (0.106 mL, 1.31 mmol) and DMAP (160 mg, 1.31 mmol). The reaction mixture was chilled to −20° C. To the chilled solution was added POCl 3 (0.122 mL, 1.31 mmol) dropwise, and then the reaction mixture was allowed to warm to rt and stirred for 1 h. Water (10 mL) was added and the mixture was stirred for 1.5 h. The layers were then separated and the organic layer was dried over Na 2 SO 4 and evaporated to dryness. The crude product was purified by HPLC on a Symmetry C8 (300×17 mm) 7 mM column eluting with a gradient of 20% B to 50% B over 7 minutes at 15 mL/min where solvent A=10 mM ammonium acetate in water pH 4.5 and solvent B=acetonitrile. The product RT=2.2 min. The desired product (5.8 mg, 4.7%) was isolated from the appropriate fractions by lyophilization as a white solid. LCMS (Conditions A) RT=1.720 min, (M+H) + =463.2. 1 H NMR (400 MHz, methanol-d 4 ) δ 7.29-7.16 (m, 8H), 4.74 (br. s., 1H), 4.61-4.34 (m, 2H), 4.01 (t, J=8.3 Hz, 1H), 3.82-3.62 (m, 1H), 3.35 (m, 2H), 3.05 (br. s., 2H), 2.79 (br. s., 2H), 2.34 (s, 4H), 2.18 (br. s., 1H), 2.02-1.87 (m, 1H), 1.83 (br. s., 1H). 19 F NMR (376 MHz, methanol-d 4 ) δ −185.143. 31 P NMR (162 MHz, methanol-d 4 ) δ −4.260. Example 3 (S)-4-((3S,4S)-3-Fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-amino-3-methylbutanoate hydrochloride [0062] Step 3A. (S)-4-((3S,4S)-3-Fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate [0063] [0064] To a solution of (R)-3-((3S,4S)-3-fluoro-4-(4-hydroxyphenyl)piperidin-1-yl)-1-(4-methylbenzyl)pyrrolidin-2-one (0.02 g, 0.052 mmol, example 1) in DCM (3 mL) was added (S)-2-((tert-butoxycarbonyl)amino)-3-methylbutanoic acid (0.059 g, 0.272 mmol) followed by DCC (0.032 g, 0.157 mmol) and DMAP (6.39 mg, 0.052 mmol). The reaction mixture was stirred at room temperature for 18 h. Water (10 mL) was then added, and the layers were separated. The aqueous layer was extracted with DCM (3×10 mL) and the organic layers were combined, dried over Na 2 SO 4 , and concentrated to a crude product. The crude product was purified by preparative TLC eluting with 35% ethyl acetate in petroleum ether to provide the purified product (S)-4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate (27 mg, 79%). LC/MS (Conditions A) RT=2.523 min, (M+H) + =582.2. 1 H NMR (400 MHz, methanol-d 4 ) δ 7.36 (d, J=8.5 Hz, 2H), 7.18 (s, 4H), 7.08 (d, J=8.5 Hz, 2H), 4.80-4.59 (m, J=10.0, 10.0, 5.0 Hz, 1H), 4.51 (d, J=15.0 Hz, 1H), 4.39 (d, J=15.0 Hz, 1H), 4.23 (dd, J=8.3, 6.3 Hz, 1H), 3.72 (t, J=8.8 Hz, 1H), 3.56-3.40 (m, 1H), 3.32-3.22 (m, 2H), 2.86-2.61 (m, 2H), 2.47 (td, J=10.0, 5.0 Hz, 1H), 2.34 (s, 3H), 2.32-2.23 (m, 1H), 2.22-2.01 (m, 2H), 1.88 (dd, J=9.5, 4.0 Hz, 2H), 1.74 (dt, J=13.4, 3.8 Hz, 1H), 1.50 (s, 9H), 1.42-1.30 (m, 1H), 1.09 (dd, J=10.0, 7.0 Hz, 6H). 19 F NMR (376 MHz, methanol-d 4 ) δ −184.32. Step 3B. (S)-4-((3S,4S)-3-Fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-amino-3-methylbutanoate hydrochloride [0065] [0066] To a solution of (S)-4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate (0.025 g, 0.043 mmol) in DCM (1.5 mL) at −20° C. was added HCl in diethyl ether (2.5 ml, 2.50 mmol, 1.0 M). The reaction mixture was slowly warmed to rt over 10 min and then allowed to stir at rt for 19 h. The solvent was then removed in vacuo to provide a pale yellow semisolid. The crude product was then purified by RP-HPLC on a Sunfire C18 (250×20 mm) 5 μm column using a gradient of 10% solvent B to 75% solvent B over 12 minutes at 15 mL/min where solvent A=0.05% HCl in water and solvent B=acetonitrile. Active fractions were concentrated by lyophilization to provide 10.2 mg (44%) of (S)-4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-amino-3-methylbutanoate hydrochloride, the titled compound of example 2 as an off-white solid. LC-MS (Method A) RT=2.20 min, (M+H) + =482.2. 1 H NMR: (400 MHz, DMSO-d 6 ) δ ppm 8.64-8.78 (m, 3H) 7.38-7.46 (m, 2H) 7.23 (d, J=8.53 Hz, 2H) 7.18 (s, 4H) 5.04-5.26 (m, 1H) 4.42 (d, J=9.54 Hz, 3H) 4.17-4.23 (m, 2H) 3.29-3.40 (m, 4H) 3.19-3.28 (m, 2H) 2.30 (s, 6H) 2.04-2.19 (m, 2H) 1.11 (dd, J=12.55, 7.03 Hz, 6H). 19 F NMR (376 MHz, DMSO-d 6 ) δ −183.904. Example 4 (S)-4-((3S,4S)-3-Fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-aminopropanoate hydrochloride [0067] Step 4A. (S)-4-((3S,4S)-3-Fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-((tert-butoxycarbonyl)amino)propanoate [0068] [0069] To a solution of (R)-3-((3S,4S)-3-fluoro-4-(4-hydroxyphenyl)piperidin-1-yl)-1-(4-methylbenzyl)pyrrolidin-2-one (0.03 g, 0.078 mmol, example 1) in DCM (5 mL) was added (S)-2-((tert-butoxycarbonyl)amino)propanoic acid (0.077 g, 0.408 mmol) followed by DCC (0.049 g, 0.235 mmol) and DMAP (9.58 mg, 0.078 mmol). The reaction mixture was stirred at rt for 18 h. Water (15 mL) was then added, and the layers were separated. The aqueous layer was extracted with DCM (3×15 mL) and the organic layers were combined, dried over Na 2 SO 4 , and concentrated to a crude product. The crude product was purified by preparative TLC eluting with 20% ethyl acetate in petroleum ether to provide the purified product (S)-4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-((tert-butoxycarbonyl)amino)propanoate (0.032 g, 0.058 mmol, 74% yield) as off-white semi solid. LC-MS (Method A) RT=2.40 min, (M+H) + =554.2. 1 H NMR (400 MHz, DMSO-d 6 ) δ 7.51 (d, J=7.0 Hz, 1H), 7.44-7.32 (m, J=8.5 Hz, 2H), 7.21-7.09 (m, 4H), 7.07-6.98 (m, J=8.5 Hz, 2H), 4.62 (d, J=4.5 Hz, 1H), 4.39 (d, J=15.1 Hz, 1H), 4.30 (d, J=15.1 Hz, 1H), 4.27-4.17 (m, 1H), 3.58 (t, J=8.5 Hz, 1H), 3.50-3.40 (m, 1H), 3.22-3.07 (m, 2H), 2.81-2.64 (m, 3H), 2.39-2.31 (m, 1H), 2.29 (s, 3H), 2.17-2.04 (m, 1H), 1.93 (dd, J=12.8, 8.3 Hz, 1H), 1.78 (br. s., 1H), 1.74-1.59 (m, 1H), 1.41 (s, 9H), 1.39 (d, J=2.5 Hz, 3H). 19 F NMR (376 MHz, DMSO-d 6 ) δ −180.172. Step 4B. (S)-4-((3S,4S)-3-Fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-aminopropanoate hydrochloride [0070] [0071] To a solution of (S)-4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-((tert-butoxycarbonyl)amino)propanoate (0.032 g, 0.058 mmol) in DCM (2 mL) at −20° C. was added HCl in diethyl ether (2.0 ml, 2.0 mmol, 1.0 M). The reaction mixture was slowly warmed to rt over 10 min and then allowed to stir at rt for 19 h. The solvent was then removed in vacuo to provide a pale yellow semisolid. The crude product was then purified by RP-HPLC on a Kinetex C18 (250×20 mm) 5 μm column using a gradient of 10% solvent B to 40% solvent B over 7 minutes at 15 mL/min where solvent A=0.05% HCl in water and solvent B=acetonitrile. Active fractions were concentrated by lyophilization to provide 4.7 mg (16%) of (S)-4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl 2-aminopropanoate hydrochloride, the titled compound of example 4 as an off-white solid. LC-MS (Method A) RT=1.762 min, (M+H) + =454. 1 H NMR (400 MHz, DMSO-d 6 ) δ 7.41 (d, J=9.0 Hz, 2H), 7.24-7.10 (m, 6H), 5.10-4.85 (m, 1H), 4.45-4.22 (m, 4H), 4.04-3.94 (m, 1H), 3.34-3.18 (m, 4H), 3.06 (d, J=12.0 Hz, 2H), 2.43-2.31 (m, 1H), 2.27 (s, 3H), 2.24-2.14 (m, 1H), 2.13-2.01 (m, 1H), 2.01-1.85 (m, 1H), 1.58 (d, J=7.0 Hz, 3H). 19 F NMR (376 MHz, DMSO-d 6 ) δ −183.778. Example 5 (S)-2-Amino-4-(4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenoxy)-4-oxobutanoic acid hydrochloride [0072] Step 5A. (S)-1-tert-Butyl 4-(4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl) 2-((tert-butoxycarbonyl)amino)succinate [0073] [0074] To a solution of (R)-3-((3S,4S)-3-fluoro-4-(4-hydroxyphenyl)piperidin-1-yl)-1-(4-methylbenzyl)pyrrolidin-2-one (0.03 g, 0.078 mmol) in DCM (5 mL) was added (S)-4-(tert-butoxy)-3-((tert-butoxycarbonyl)amino)-4-oxobutanoic acid (0.118 g, 0.408 mmol) followed by DCC (0.049 g, 0.235 mmol) and DMAP (9.58 mg, 0.078 mmol). The reaction was stirred at rt for 18 hours. Water (15 mL) was then added, and the layers were separated. The aqueous layer was extracted with DCM (3×15 mL) and the organic layers were combined, dried over Na 2 SO 4 , and concentrated to a crude product. The crude product was purified by preparative TLC eluting with 25% ethyl acetate in petroleum ether to provide the purified product (37 mg, 68%) as an off-white semi solid. LC-MS (Method A) RT=2.55 min, (M+H) + =654.4. 1 H NMR (400 MHz, DMSO-d 6 ) δ 7.46-7.34 (m, 2H), 7.20-6.98 (m, 6H), 4.82-4.53 (m, 1H), 4.43-4.24 (m, 2H), 4.11 (d, J=14.1 Hz, 1H), 3.58 (t, J=8.8 Hz, 1H), 3.48-3.39 (m, 1H), 3.22-3.07 (m, 3H), 3.02 (dd, J=16.1, 6.5 Hz, 1H), 2.87 (dd, J=15.8, 7.8 Hz, 1H), 2.78-2.63 (m, 2H), 2.38-2.31 (m, 1H), 2.29 (s, 3H), 2.17-2.03 (m, 1H), 1.98-1.86 (m, 1H), 1.78 (br. s., 1H), 1.74-1.58 (m, 1H), 1.42 (s, 9H), 1.39 (s, 9H). 19 F NMR (376 MHz, DMSO-d 6 ) δ −180.707. Step 5B. (S)-2-amino-4-(4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenoxy)-4-oxobutanoic acid hydrochloride [0075] [0076] To a solution of (S)-1-tert-butyl 4-(4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl) 2-((tert-butoxycarbonyl)amino)succinate (0.032 g, 0.049 mmol) in DCM (2 mL) at −20° C. was added HCl in diethyl ether (2.0 ml, 2.0 mmol, 1.0 M). The reaction mixture was slowly warmed to rt over 10 min and then allowed to stir at rt for 19 h. The solvent was then removed in vacuo to provide a pale yellow semisolid. The crude product was then purified by RP-HPLC on a YMC Triart C18 (150×19 mm) 5 μm column using a gradient of 10% solvent B to 40% solvent B over 7 minutes at 15 mL/min where solvent A=0.05% HCl in water and solvent B=acetonitrile. Active fractions were concentrated by lyophilization to provide 17 mg (57%) of (S)-2-amino-4-(4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenoxy)-4-oxobutanoic acid hydrochloride, the titled compound of example 5 as an off-white solid. LC-MS (Method A) RT=1.808 min, (M+H) + =498.2 1 H NMR (400 MHz, DMSO-d 6 ) δ 7.36 (d, J=8.5 Hz, 2H), 7.21-7.03 (m, 8H), 6.75 (d, J=8.5 Hz, 1H), 4.95-4.72 (m, 1H), 4.42-4.24 (m, 3H), 4.10 (t, J=5.3 Hz, 1H), 4.07-4.01 (m, 1H), 3.93-3.84 (m, 1H), 3.83-3.68 (m, 1H), 3.33-3.10 (m, 5H), 3.04 (br. s., 1H), 2.93 (br. s., 1H), 2.89-2.71 (m, 2H), 2.26 (s, 3H), 1.96 (br. s., 1H), 1.82 (br. s., 1H). 19 F NMR (376 MHz, DMSO-d 6 ) δ −180.707. Example 6 (R)-1-(4-(Difluoromethyl)benzyl)-3-((3S,4S)-3-fluoro-4-(4-hydroxyphenyl)piperidin-1-yl)pyrrolidin-2-one [0077] [0078] A solution of (S)-1-(4-(difluoromethyl)benzyl)-2-oxopyrrolidin-3-yl methanesulfonate (500 mg, 1.57 mmol, intermediate M) in 5.0 mL of acetonitrile was added dropwise over 1.5 h to a stirred mixture of 4-((3S,4S)-3-fluoropiperidin-4-yl)phenol, hydrochloride (363 mg, 1.57 mmol, intermediate F) and N,N-diisopropylethylamine (1.09 mL, 6.26 mmol) in 5.0 mL of acetonitrile maintained at 85° C. After complete addition, the reaction mixture was stirred at 85° C. for 16 h. [0079] The reaction mixture was concentrated in vacuo. The residue was purified using silica gel column chromatography (0-100% EtOAc/hexanes) to afford a diasteromeric mixture (partial epimerization of the lactam stereocenter) of 1-(4-(difluoromethyl)benzyl)-3-((3S,4S)-3-fluoro-4-(4-hydroxyphenyl)piperidin-1-yl)pyrrolidin-2-one (235 mg, 35% yield). A sample of the diastereomeric mixture (780 mg) was separated by preparative chiral SFC (column=Lux Cellulose-2 (21×250 mm, 5 μm); isocratic solvent=20% methanol (with 15 mM ammonia)/80% CO 2 ; temp=35° C.; flow rate=60 mL/min; injection volumn=1.0 mL (˜20 mg/mL in MeOH) stacked @ 13 min intervals; λ=210 nM; Peak 1=19.6 min, Peak 2=24.5 min) to afford the titled compounds of example 6 (Peak-1, 389 mg) and (S)-1-(4-(difluoromethyl)benzyl)-3-((3S,4S)-3-fluoro-4-(4-hydroxyphenyl)piperidin-1-yl)pyrrolidin-2-one (Peak 2, 242 mg). Data for Example 6: LC-MS m/z 419.3 (M+H + ); 1 H NMR (500 MHz, chloroform-d) δ 7.50 (d, J=7.9 Hz, 2H), 7.34 (d, J=7.9 Hz, 2H), 7.15 (d, J=8.5 Hz, 2H), 6.91-6.80 (m, 2H), 6.65 (t, J=56.4 Hz, 1H), 4.96 (s, 1H), 4.77-4.43 (m, 3H), 3.68 (t, J=8.8 Hz, 1H), 3.42-3.33 (m, 1H), 3.29-3.14 (m, 2H), 2.85 (d, J=10.4 Hz, 1H), 2.78-2.69 (m, 1H), 2.69-2.57 (m, 1H), 2.48 (td, J=9.9, 4.9 Hz, 1H), 2.21-2.11 (m, 1H), 2.04 (dq, J=13.0, 8.6 Hz, 1H), 1.94-1.82 (m, 2H)). The relative and absolute configuration of Example 114, P-1 was confirmed by single crystal X-ray analysis. Example 7 4-((3S,4S)-3-fluoro-1-((R)-1-(4-methylbenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl dihydrogen phosphate [0080] [0081] To a suspension of (R)-1-(4-(difluoromethyl)benzyl)-3-((3S,4S)-3-fluoro-4-(4-hydroxyphenyl)piperidin-1-yl)pyrrolidin-2-one (100 mg, 0.239 mmol, from example 6) in dichloromethane (10 mL) was added triethylamine (0.233 ml, 1.67 mmol) at −20° C. To the chilled solution was added POCl 3 (0.111 ml, 1.20 mmol) at −20° C., and then the reaction mixture was stirred for 2-3 hours at −20° C. Water (10 mL) was added and the mixture was stirred for 1.5 h. The mixture was extracted with dichloromethane. The organic layers was dried over sodium sulfate, filtered, and concentrated in vacuo. The crude product was purified by reverse phase preparatory HPLC on a LUNA C8 (250 mm×19 mm ID) 5 μm column eluting with a gradient of solvent A=10 mM ammonium acetate in water pH 4.5 and solvent B=acetonitrile. [0082] The titled compound of example 7 (21 mg, 18%) was isolated from the appropriate fractions by lyophilization as a white solid. LCMS (M+H) + =499.2; 1 H NMR (400 MHz, METHANOL-d 4 ) δ ppm 7.55 (d, J=8.03 Hz, 2H) 7.41 (d, J=8.03 Hz, 2H) 7.21 (s, 4H) 6.62-6.92 (m, 1H) 4.51-4.64 (m, 3H) 3.76 (t, J=8.78 Hz, 1H) 3.43-3.51 (m, 1H) 3.36 (d, J=6.02 Hz, 1H) 3.26-3.30 (m, 1H) 2.81 (br. s., 1H) 2.70-2.78 (m, 1H) 2.59-2.69 (m, 1H) 2.48 (td, J=9.91, 4.77 Hz, 1H) 2.17-2.27 (m, 1H) 2.06-2.15 (m, 1H) 1.80-1.89 (m, 2H). Example 8 (R)-1-(4-Fluorobenzyl)-3-(4-(4-hydroxyphenyl)piperidin-1-yl)pyrrolidin-2-one [0083] [0084] To a solution of 1-(4-fluorobenzyl)-3-(4-(4-methoxyphenyl)piperidin-1-yl)pyrrolidin-2-one (3 g, 7.9 mmol, intermediate S) in dry dichloromethane (100 mL) under a N2 atmosphere at −78° C. was added 1 M borontribromide in dichloromethane (39 mL, 39 mmol) and the resulting mixture was allowed to warm up to room temperature over 3 h, with stirring. The reaction was quenched with water (30 mL) and the organic layer was separated, washed with water and brine, and concentrated. The crude product was purified by flash chromatography on silica gel using 15% EtOAc in petroleum ether to yield racemic 1-(4-fluorobenzyl)-3-(4-(4-hydroxyphenyl)piperidin-1-yl)pyrrolidin-2-one (2.1 g, 73% yield); 1 H NMR (400 MHz, DMSO-d 6 ) δ ppm 1.49-1.74 (m, 4H) 1.90-2.11 (m, 2H) 2.24-2.42 (m, 2H) 2.65-2.80 (m, 2H) 2.99-3.23 (m, 3H) 3.40-3.54 (m, 1H) 4.27-4.46 (m, 2H) 6.61-6.70 (m, 2H) 6.95-7.04 (m, 2H) 7.17-7.31 (m, 4H) 9.10-9.16 (m, 1H). LCMS (ES-API) 369.2 m/z (M+H) + . A portion of the racemate (40 mg) was separated via SFC on a Chiralpak-IA 250 mm×4.6 mm, 5 μn column eluting with 35% solvent B, where solvent A=CO 2 and solvent B=0.3% DEA in methanol at a total flow of 3 mL/min. Peak 1 showed a RT of 4.35 min (11 mg) and Peak 2 showed a RT of 6.29 min (13 mg). Data for example 8 (Peak 2): LC/MS (M+H) + =369.2; 1 H NMR (400 MHz, DMSO-d 6 ) δ ppm 1.47-1.59 (m, 1H) 1.65-1.75 (m, 1H) 1.84-1.96 (m, 1H) 2.03-2.12 (m, 1H) 2.24-2.43 (m, 1H) 2.63-2.72 (m, 2H) 2.72-2.85 (m, 2H) 2.96-3.05 (m, 2H) 3.09-3.23 (m, 2H) 3.41-3.54 (m, 1H) 4.23-4.50 (m, 2H) 6.58-6.71 (m, 2H) 6.96-7.10 (m, 2H) 7.15-7.21 (m, 2H) 7.26-7.34 (m, 2H) 9.06-9.19 (m, 1H). Example 9 (R)-4-(1-(1-(4-fluorobenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl dihydrogen phosphate [0085] [0086] Phosphorus oxychloride (1.27 mL, 13.6 mmol) was added to a round bottom flask charged with THF (10 mL). The solution was cooled below 0° C. using an ice/methanol bath. A suspension of (R)-1-(4-fluorobenzyl)-3-(4-(4-hydroxyphenyl)piperidin-1-yl)pyrrolidin-2-one (1.00 g, 2.71 mmol, example 8) in THF (18 mL) was added. After 5 min, triethylamine (0.946 mL, 6.79 mmol) was added slowly at a bath temperature below 5° C. The reaction mixture was stirred at 0° C. for 90 min. A solution of 1 N aqueous sodium hydroxide (8.69 mL, 8.69 mmol) was added dropwise. The pH was measured to be ˜0. The mixture was allowed to warm to rt and stir for 3 h. The crude reaction mixture was concentrated in vacuo at <30° C. to afford a clear solution. The solution was triturated with 1 N aqueous NaOH to pH ˜1. The mixture was cooled in an ice bath. A semi-solid crashed out. All liquid was decanted off. The semi-solid was suspended in 90% ethanol and then a collected by vacuum filtration. The product was presumed to be the HCl salt of (R)-4-(1-(1-(4-fluorobenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl dihydrogen phosphate (560 mg, 42%). A solution of 25% sodium methoxide in methanol (250 mg, 1.16 mmol) was added to a slurry of (R)-4-(1-(1-(4-fluorobenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)phenyl dihydrogen phosphate, HCl (560 mg, 1.16 mmol) in methanol. The mixture was stirred until clear and then concentrated in vacuo. The residue was dissolved in 90% ethanol/water and chilled in the freezer. The solid precipitate was collected using vacuum filtration. The solid was dried under high vacuum to afford the titled compound of example 9 (230 mg, 19% yield): LC/MS (M+H) + =449.2; 1 H NMR (500 MHz, methanol-d 4 ) δ 7.35-7.25 (m, 2H), 7.21-7.11 (m, 4H), 7.11-7.03 (m, 2H), 4.55-4.35 (m, 2H), 3.61 (t, J=8.8 Hz, 1H), 3.30-3.20 (m, 2H), 3.19-3.11 (m, 1H), 2.92-2.84 (m, 1H), 2.75 (td, J=11.1, 3.5 Hz, 1H), 2.55-2.41 (m, 2H), 2.23-2.13 (m, 1H), 2.12-2.00 (m, 1H), 1.84-1.70 (m, 4H); 31 P NMR (202 MHz, methanol-d 4 ) δ ppm −3.38. Biological Methods [0087] Radioligand Binding Assay. [0088] Binding experiments to determine binding to NR2B-subtype NMDA receptors were performed on forebrains of 8-10 weeks old male Sprague Dawley rats (Harlan, Netherlands) using 3 H Ro 25-6981 (Mutel V; Buchy D; Klingelschmidt A; Messer J; Bleuel Z; Kemp J A; Richards J G. Journal of Neurochemistry, 1998, 70(5):2147-2155. Rats were decapitated without anesthesia using a Guillotine (approved by animal ethics committee) and the harvested brains were snap-frozen and stored at −80° C. for 3-6 months for membrane preparation. [0089] For membrane preparation, rat forebrains were thawed on ice for 20 minutes in homogenization buffer composed of 50 mM KH 2 PO 4 (pH adjusted to 7.4 with KOH), 1 mM EDTA, 0.005% Triton X 100 and protease inhibitor cocktail (Sigma Aldrich). Thawed brains were homogenized using a Dounce homogenizer and centrifuged at 48000×g for 20 min. The pellet was resuspended in cold buffer and homogenized again using a Dounce homogenizer. Subsequently, the homogenate was aliquoted, snap-frozen and stored at −80° C. for not more than 3-4 months. [0090] To perform the competition binding assay, thawed membrane homogenate was added to each well of a 96-well plate (20 μg/well). The experimental compounds were serially diluted in 100% DMSO and added to each row of the assay plate to achieve desired compound concentrations, keeping the DMSO concentration in the assay plate at 1.33% of the final reaction volume. Next, 3 H Ro 25-6981 (4 nM) was added to the assay plate. After incubation for 1 hr at room temperature, the membrane bound radioligand was harvested on to GF/B filter plates (treated with 0.5% PEI for 1 hr at room temperature). The filter plates were dried at 50° C. for 20 mins, incubated with microscint 20 for 10 minutes and finally, the counts were read on TopCount (Perkin Elmer). Non-specific binding was determined using MK-0657 (the preparation of this compound is described as example 1 in WO 2004 108705 (40 μM). CPM values were converted to % inhibition and the concentration response curves were plotted using custom made software. Each experiment was repeated at least twice to obtain the final binding K i values for experimental compounds. Using this assay, the compound of example 1 showed a binding Ki of 4 nM, the compound of example 6 showed a binding Ki of 4 nM, the compound of example 8 showed a binding Ki of 1.4 nM. [0091] Ex Vivo Occupancy Assay. [0092] This assay demonstrates that the compound of example 1 occupies brain-resident NR2B-subtype receptors in animals after dosing. 7-9 weeks old male CD-1 mice were dosed intravenously in a vehicle consisting of 10% dimethylacetamide, 40% PEG-400, 30% hydroxypropyl betacyclodextrin, and 30% water with experimental compounds and the forebrains were harvested 15 minutes post-dosing by decapitation. The brain samples were immediately snap-frozen and stored at −80° C. On the following day, the dosed brain samples were thawed on ice for 15-20 minutes followed by homogenization using Polytron for 10 seconds in cold homogenization buffer composed of 50 mM KH 2 PO 4 (pH adjusted to 7.4 with KOH), 1 mM EDTA, 0.005% Triton X 100 and protease inhibitor cocktail (Sigma Aldrich). The crude homogenates were further homogenized using a Dounce homogenizer and the homogenized membrane aliquots from all animals were flash-frozen and stored at −80° C. until further use. The whole homogenization process was performed on ice. [0093] For determining occupancy, the membrane homogenates were first thawed on ice and then needle-homogenized using a 25 gauge needle. The homogenized membrane (6.4 mg/ml) was added to a 96-well plate followed by addition of 3 H Ro 25-6981 (6 nM). The reaction mixture was incubated for 5 minutes on a shaker at 4° C. and then harvested onto GF/B filter plates (treated with 0.5% PEI for 1 hr at room temperature). The filter plates were dried at 50° C. for 20 mins, incubated with microscint 20 for 10 minutes and read on TopCount (Perkin Elmer). Each dose or compound group consisted of 4-5 animals. The control group of animals was dosed with vehicle alone. Membrane from each animal was added in triplicates to the assay plate. Non-specific binding was determined using 10 μM Ro 25-6981 added to the wells containing membrane homogenates from vehicle-dosed animals. Specific counts/minute was converted to % occupancy at each dose of a compound for each animal using the following equation: [0000] %   Occupancy   ( animal   A ) = 100 - ( specific   CPM   of   animal   A Average   CPM   from   control   group × 100 ) [0000] Using this procedure, the compound of example 1 showed 95% NR2B receptor occupancy after a 3 mg/Kg i.v. dose. Drug levels were determined by mass spectroscopy in the usual manner. Drug levels in the blood plasma were 1106 nM in at this dose, and drug levels in the homogonized brain tissue were 1984 nM. The compound of example 6 showed 97% NR2B receptor occupancy after a 3 mg/Kg i.v. dose. Drug levels in the blood plasma were 1800 nM in at this dose, and drug levels in the homogonized brain tissue were 2200 nM. The compound of example 8 showed 96% NR2B receptor occupancy after a 3 mg/Kg i.v. dose. Drug levels in the blood plasma were 570 nM at this dose, and drug levels in the homogonized brain tissue were 900 nM. [0094] hERG Electrophysiology Assay. [0095] The experimental compounds were assessed for hERG activity on HEK 293 cells stably expressing hERG channels using patch clamp technique. Coverslips plated with hERG expressing cells were placed in the experimental chamber and were perfused with a solution composed of (in mM): 140 NaCl, 4 KCl, 1.8 CaCl 2 , 1 MgCl 2 , 10 Glucose, 10 HEPES (pH 7.4, NaOH) at room temperature. Borosilicate patch pipettes had tip resistances of 2-4 Mohms when filled with an internal solution containing: 130 KCl, 1 MgCl 2 , 1 CaCl 2 , 10 EGTA, 10 HEPES, 5 ATP-K 2 (pH 7.2, KOH). The cells were clamped at −80 mV in whole cell configuration using an Axopatch 200B (Axon instruments, Union City, Calif.) patch clamp amplifier controlled by pClamp (Axon instruments) software. Upon formation of a gigaseal, the following voltage protocol was repeatedly (0.05 Hz) applied to record tail currents: depolarization step from −80 mV to +20 mV for 2 seconds followed by a hyperpolarization step to −65 mV (3 seconds) to elicit tail currents and then, back to the holding potential. Compounds were applied after stabilization of tail current. First, tail currents were recorded in presence of extracellular solution alone (control) and subsequently, in extracellular solution containing increasing compound concentrations. Each compound concentration was applied for 2-5 minutes. The percentage inhibition at each concentration was calculated as reduction in peak tail current with respect to the peak tail current recorded in the presence of control solution. Data analysis was performed in custom made software. The percent inhibitions at different concentrations were plotted to obtain a concentration response curve, which was subsequently fitted with a four parameter equation to calculate the hERG IC 50 value. Using this procedure, the compound of example 1 is a poor inhibitor of the hERG channel, with an IC 50 =28 The compound of example 6 is a poor inhibitor of the hERG channel, with an IC 50 =13.5 μM. [0096] Mouse Forced swim test (mFST). Forced Swim Test (FST) is an animal model used to assess antidepressant compounds in preclinical studies. The FST was performed similar to the method of Porsolt et al. with modifications (Porsolt R D, Bertin A, Jalfre M. Behavioral despair in mice: a primary screening test for antidepressants. Arch Int Pharmacodyn Ther 1977; 229:327-36). In this paradigm, mice are forced to swim in an inescapable cylinder filled with water. Under these conditions, mice will initially try to escape and eventually develop immobility behavior; this behavior is interpreted as a passive stress-coping strategy or depression-like behavior. Swim tanks were positioned inside a box made of plastic. Each tank was separated from each other by opaque plastic sheets to the height of cylinders. Three mice were subjected to test at a time. Swim sessions were conducted for 6 min by placing mice in individual glass cylinders (46 cm height×20 cm diameter) containing water (20-cm deep, maintained at 24-25° C.). At this water level, the mouse tail does not touch the bottom of the container. The mouse was judged to be immobile whenever it remained floating passively without struggling in the water and only making those movements necessary to keep its nose/head above the water and to keep it afloat. The duration of immobility was evaluated during the total 6 min of the test and expressed as duration (sec) of immobility. Each mouse was tested only once. At the end of each session, mice were dried with a dry cloth and returned to their home cage placed on a thermal blanket to prevent hypothermia. Water was replaced after each trial. All testing sessions were recorded with a video camera (Sony Handicam, Model: DCR-HC38E; PAL) and scoring was done using the Forced Swim Scan, Version 2.0 software (Clever Systems Inc., Reston, Va., USA; see Hayashi E, Shimamura M, Kuratani K, Kinoshita M, Hara H. Automated experimental system capturing three behavioral components during murine forced swim test. Life Sci. 2011 Feb. 28; 88(9-10):411-7 and Yuan P, Tragon T, Xia M, Leclair C A, Skoumbourdis A P, Zheng W, Thomas C J, Huang R, Austin C P, Chen G, Guitart X. Phosphodiesterase 4 inhibitors enhance sexual pleasure-seeking activity in rodents. Pharmacol Biochem Behav. 2011; 98(3):349-55). For NCE testing: Test compound was administered in mice 15 min before swim session by i.v. route and immobility time was recorded for next 6 min. At the end of FST, the mouse were euthanized by rapid decapitation method and plasma and brain samples were collected and stored under −80° C. till further analysis. In the mouse forced swim assay, the compound of example 1 was dosed intravenously in a vehicle of 30% hydroxypropyl betacyclodextrin/70% citrate buffer pH 4 at a 5 mL/Kg dosing volume. The compound of example 1 demonstrated a statistically significant decrease in immobility time at 1 mg/Kg under these conditions. Drug levels were 268+/−128 nM in the plasma and 749+/−215 nM in the brain at this dose. The NR2B receptor occupancy was determined as reported above and was determined to be 73%. The compound of example 6 demonstrated a statistically significant decrease in immobility time at 1 mg/Kg under these same conditions. Drug levels were 360 nM in the plasma. The NR2B receptor occupancy was determined to be 79%.

The disclosure generally relates to compounds of formula I, including their salts, as well as compositions and methods of using the compounds. The compounds are ligands for the NR2B NMDA receptor and may be useful for the treatment of various disorders of the central nervous system.

CLAIM OF PRIORITY [0001] The present application claims priority from Japanese application JP 2004-263195 filed on Sep. 10, 2004, the content of which is hereby incorporated by reference into this application. FIELD OF THE INVENTION [0002] The present invention relates to a delay locked loop (DLL) circuit, and in particular, to a delay locked loop circuit suitable for use in a digital predistortion circuit for compensating for nonlinear distortion occurring to an analog circuit (for example, a power amplifier), in a baseband, a digital predistortion type transmitter using the same, and a wireless base station. BACKGROUND OF THE INVENTION [0003] With the widespread use of cellular phones, it has lately become essential to make effective use of radio wave resources, and attention is being focused on CDMA, and OFDM as wireless communication systems high in frequency utilization efficiency. It is known that momentary maximum power at about 10 dB or greater against average transmission power occurs to a transmitter at a base station for these systems. [0004] Meanwhile, a power amplifier of the transmitter at the base station has a property such that high efficiency is generally obtained at the time of a large output operation, but there occurs deterioration in linearity at that time because of output saturation. Since such nonlinear distortion causes a transmitted spectrum to spread, resulting in interference with other bands, a quantity of disturbing waves generated is strictly regulated by Wireless Telegraphy Act. [0005] With the transmitter at the base station, it is regarded preferable from the viewpoint of equipment size and running cost to execute operation in a high-efficiency state by raising output amplitude of the power amplifier, however, with CDMA, and OFDM, operation at high efficiency has become difficult to execute because nonlinear distortion is prone to occur thereto. [0006] As a method of overcoming such a problem as described, various method of linearizing the output of the power amplifier by use of distortion-compensating techniques have so far been developed, and as one of such methods, digital predistortion for executing compensation for distortion in a baseband has been well known. The conventional configuration of the digital predistortion includes a configuration wherein a delay unit is made up of an FIR type digital filter (refer to Patent Document 1). [0007] [Patent Document 1] JP-A No. 189685/2001 [0008] FIG. 3 shows a configuration example of a digital predistortion type transmitter at a wireless base station, and FIG. 4 shows a configuration of a predistortion unit 303 by way of example. [0009] In FIG. 3 , a transmission signal fed from a controller 300 is processed for coding by a modulator 301 to be subsequently subjected to bandwidth control by a baseband-signal-processing unit 302 , which outputs quadrature IQ signals Ii, Qi to be further processed for compensation for distortion by a predistortion unit 303 to be thereby converted into analog signals by a D/A converter 304 , and a quadrature modulator 305 executes conversion of frequencies of the analog signals into a radio frequency band, whereupon a power amplifier 306 amplifies power, thereby sending out radio waves into the air from an antenna 310 through an antenna sharing unit 309 . In this case, nonlinear distortion occurs to the power amplifier 306 at the time of a large output, which, however, can be deemed equivalent to a case where the nonlinear distortion is superimposed on the output of a linear amplifier 307 . [0010] In order to effectively implement predistortion, it is necessary to accurately cancel out nonlinear characteristics of the power amplifier 306 by accurately grasping an amount of the nonlinear distortion that has occurred. Accordingly, transmission radio waves are converted in frequency to an IF band with the use of a mixer 311 to be subsequently converted into a digital signal by an A/D converter 312 , and the digital signal is demodulated by a digital quadrature demodulator 313 to be thereby fed back to the predistortion unit 303 . As for a configuration of a demodulation unit, a digital IF type excellent in demodulation precision has been described, however, various configurations other than that, including an analog quadrature modulator, are conceivable for adoption. [0011] Next, referring to FIG. 4 , a configuration of the predistortion unit 303 is described hereinafter. In FIG. 4 , s delay unit 104 outputs signals Id, Qd obtained by delaying first input signals Ii, Qi by an integer (n) multiple of sample frequency. A subtractor 103 computes a difference between the signals Id, Qd, and second first input signals Ir, Qr. Based on a differential signal as obtained, an adaptive signal processor 102 controls a predistortor 101 so as to render the differential signal coming to zero. For adaptive signal processing, use is usually made of an algorithm for minimizing the square of an error, that is, distortion power, such as the least mean square algorithm, and recursive least square algorithm, based on the gradient method. [0012] If nonlinear distortion has been accurately extracted by the subtractor 103 , reduction in the nonlinear distortion can be implemented as a result of the adaptive signal processing described as above. However, if the extraction of the nonlinear distortion is incomplete, a control error results even in a state where the nonlinear distortion is at zero because the differential signal is not eliminated. In other words, in order to implement effective predistortion, it becomes necessary that delay on a signal path from the predistortor 101 to the quadrature demodulator 313 have been corrected by the delay unit 104 . [0013] However, while a delay quantity of the former does not always correspond to an integer multiple of the sample frequency since the same passes through analog elements, a delay quantity of the latter corresponds to nothing but the integer multiple of the sample frequency since the same is generated in a latch circuit. More specifically, if the delay quantity of the former is broken down into a component “n” corresponding to the integer multiple of the sample frequency, and a component “a” less than one sample frequency, the component “n” can be corrected, but it is difficult to correct the component “a.” [0014] In Patent Document 1, there is disclosed a technology for correcting a delay quantity “a” less than one sample frequency. In this case, use is made of an FIR filter as means for causing the delay quantity less than one sample frequency to occur. In the case of this example, follow-up property thereof, against variation in delay time, is poor because delay time is decided prior to the start of a distortion-compensation operation. Accordingly, there is disclosed an example of creating a delay locked loop for controlling a clock phase of the A/D converter 312 . [0015] With delay correction means using the FIR filter as described in the conventional technology, an amplitude characteristic becomes flat only in the case where a tap factor is “0 0 . . . .. 010 . . . .. 0 0”, and when delay is set to less than one sample frequency, there arises a problem that the amplitude characteristic intrinsically has waviness occurring thereto, thereby impairing accuracy in distortion extraction by subtraction. Further, since delay correction is implemented by means of the FIR, there is a tendency that relatively large and redundant delay (corresponding to not less than 16 samples in the case of an embodiment of the conventional technology) is added. thereby creating a factor for interfering with higher speed in adaptive signal processing. [0016] Still further, there is a problem with the delay locked loop as described in the conventional technology in that there is the needs for analog components such as a D/A converter for controlling the clock of the A/D converter 312 , a smoothing filter, and a VCO in addition to those components shown in FIG. 3 . Furthermore, in addition to an increase in the number of the analog components, there is a problem with the performance thereof in that jitter is prone to occur to clock due to the effect of quantization noises of the D/A converter, and thermal noises of the VCO, and further, the retention capability of control voltage is low due to the effect of an offset voltage, thereby causing the delay locked loop susceptible to be out of sync at the time of no signal. SUMMARY OF THE INVENTION [0017] The invention has been developed in order to resolve the problem with the conventional technology as described above, and for example, a representative embodiment of the invention is as described hereunder. [0018] That is, the invention provides a delay locked loop circuit which comprises: a variable delay element for receiving first input IQ signals; a subtractor connected to output terminals of the variable delay element, for receiving signals based on output signals of the variable delay element, and second input IQ signals; a delay comparator connected to the output terminals of the variable delay element, for receiving the output signals of the variable delay element; and a smoothing filter connected to an output terminal of the delay comparator, and to an input terminal of the variable delay element, for receiving and smoothing an output signal of the delay comparator, and outputting a smoothed signal to the variable delay element, in which either the first input IQ signals or the second input IQ signals are signals generated as a result of output IQ signals undergoing digital-to-analog conversion, and again undergoing analog-to-digital conversion after passing through an analog circuit, and delay control is implemented for checking distortion occurring to the output IQ signals due to the same passing through the analog circuit by means of the variable delay element. [0019] In particular, with the use of an IIR filter as the variable delay element, the delay locked loop can be fully digitalized as an analog component is eliminated therefrom, so that it becomes possible not only to reduce the number of analog components, but also to avoid the problems of jitter and out-of-sync. Furthermore, since an FIR filter is not in use in this case, amplitude characteristic of the loop can be rendered fully smooth, and redundant delay can be suppressed to an extremely small magnitude. [0020] Thus, with the delay locked loop according to the invention, delay between two kinds of signals can be corrected substantially exactly down to a minute delay less than one sample frequency. BRIEF DESCRIPTION OF THE DRAWINGS [0021] FIG. 1 is a block diagram showing a first embodiment of the invention; [0022] FIG. 2 is a block diagram showing a second embodiment of the invention; [0023] FIG. 3 is a block diagram showing a configuration of a predistortion type transmitter at a wireless base station; [0024] FIG. 4 is a block diagram showing a configuration of a predistortion unit; [0025] FIG. 5 is a block diagram showing a configuration of a block of delay comparison and smoothing; [0026] FIG. 6 is a block diagram showing a configuration example of an IIR filter (a lattice secondary all-pass type); [0027] FIG. 7 is a diagram showing frequency characteristics in the case of the group delay characteristics being at the maximum smoothness; [0028] FIG. 8 is a diagram showing the frequency characteristics in the case of the frequency characteristics being rendered wider in bandwidth ranging from f=0 to f=fs/4; and [0029] FIG. 9 is a block diagram showing a third embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0000] First Embodiment [0030] A first embodiment of the invention is described hereinafter with reference to the accompanying drawings. A configuration shown in FIG. 1 is the same as the configuration shown in FIG. 4 except that a delay comparator 106 , a smoothing filter 107 , and an IIR filter 105 are additionally provided. The delay comparator 106 outputs a signal according to a delay difference between signals Id, Qd, which are first input signals Ii, Qi, after delayed, and output signals If, Qf of the IIR filter 105 . The smoothing filter 107 outputs a signal P representing an output of the delay comparator 106 after removing high-pass random components thereof. The IIR filter 105 is a filter circuit acting on second input signals Ir, Qr, causing a delay quantity to undergo a change according to the signal P. [0031] FIG. 5 shows respective configurations of the delay comparator 106 , and the smoothing filter 107 by way of example. First, on the basis of the reference signals Id, Qd, and the input signals If, Qf, respective momentary powers Wd, Wf are found. To find the respective momentary powers, it is sufficient to calculate the sum of the squares of the respective signals IQ. Subsequently, the momentary power Wd is kept delayed by one sample through a unit delay 203 , and the product of the momentary power Wd as delayed and the momentary power Wf is calculated with the use of a multiplier 206 . Separately from this, the momentary power Wf is delayed by two samples through unit delays 204 , 205 , and the product of the momentary power Wf as delayed, and the momentary power Wd as delayed is calculated with the use of a multiplier 207 . By calculating a difference between an output of multiplier 206 and an output of multiplier 207 , delay comparison based on correlation of the signals can be executed. However, with an output of the delay comparator 106 , a time average value contains not only delay information but also the high-pass random components attributable to the signals, so that the output is smoothed out by the smoothing filter 107 before outputting a signal P. As an example of a configuration of the smoothing filter 107 , use can be made of an integrator comprising an adder 209 , a unit delay 210 , and a constant multiplier 211 . As the output of the delay comparator 106 becomes zero at the time of no signal, an output of the smoothing filter 107 is retained at a constant value as a result of integration, and since the same is a digital circuit, retention capability thereof is perfect. [0032] Now, an IIR filter is described hereinafter. Various configurations of the IIR filter are conceivable, and by way of example, there can be cited a lattice secondary all-pass filter as shown in FIG. 6 . The transfer function thereof is represented by expression (1), the amplitude characteristic thereof is constant regardless of frequency, and the group delay characteristic thereof varies depending on two parameters, that is, multiplier factors P 1 , P 2 : Iout ⁡ ( z ) Iin ⁡ ( z ) = Qout ⁡ ( z ) Qin ⁡ ( z ) = P1 + P2 ⁡ ( 1 + P1 ) ⁢ z - 1 + z - 2 1 + P2 ⁡ ( 1 + P1 ) ⁢ z - 1 + P1z - 2 ( 1 ) [0033] In order to constitute a feedback loop, it is required that control be implemented by a single parameter P. Accordingly, functions P 1 =F 1 (P), P 2 =F 2 (P), based on single parameter P, are set up, and by imposing an appropriate restrictive condition on P 1 and P 2 , the two parameters are reduced to one parameter. Meanwhile, with the IIR filter, it is intrinsically impossible to obtain a linear phase characteristic (group delay smoothing characteristic), so that it is necessary to implement this by approximation. Accordingly, the restrictive condition described is decided in such a way as to give group delay smoothness. However, since various methods of deciding the same are conceivable depending on the method of the approximation, two cases are shown hereinafter. [0034] If the restrictive condition as a first case is decided such that a group delay low-pass characteristic has the maximum smoothness, F 1 (P), and F 2 (P) are represented by expression (2): F1 ⁡ ( P ) = P ⁡ ( P + 1 ) 8 - P ≅ 0.12 ⁢ P + 0.12 ⁢ P 2 ⁢ ⁢ F2 ⁡ ( P ) = P ⁡ ( P - 8 ) 8 + P 2 ≅ - 1.04 ⁢ P - 0.03 ⁢ P 2 ( 2 ) [0035] Shown in FIG. 7 is a frequency characteristic diagram obtained by plotting the group delay characteristics in this case, using the parameter P as a parameter. The group delay smoothness in a low-pass range is found extremely good, but an increase in frequency is accompanied by large variation in delay. [0036] If a condition is added as a second case such that a group delay quantity at f=0 is equal to a group delay quantity at f=fs/4, F 1 (P), and F 2 (P) are represented by expression (3): F1 ⁡ ( P ) = P ⁡ ( P + 1 ) 4 - P ≅ 0.23 ⁢ P + 0.24 ⁢ P 2 ⁢ ⁢ F2 ⁡ ( P ) = P ⁡ ( P - 4 ) 4 + P 2 ≅ - 1.08 ⁢ P - 0.06 ⁢ P 2 ( 3 ) [0037] Shown in FIG. 8 is a frequency characteristic diagram obtained by plotting the group delay characteristics in this case, using the parameter P as a parameter. Group delay is found somewhat wavy in a range of f=0 to f=fs/4; however, if such waviness is permissible, the frequency characteristics are deemed to be wider in bandwidth than in the first case. In either case, by varying the parameter P in a range of −1 to 0, the delay quantity can be continuously varied from one sample up to two samples. [0038] Further, exact formulas of the functions of F 1 (P), and F 2 (P), respectively, are based on the four fundamental rules of arithmetic, and can therefore be implemented in a digital circuit, however, it need only be sufficient to execute multiplication and addition by employing polynomial approximation as described in expressions (2), and (3), thereby simplifying calculation. Furthermore, if relationships between corresponding functions are stored in a table, the exact formulas can be implemented even without execution of calculation. [0039] With the present embodiment of the invention, the delay comparator 106 , the smoothing filter 107 , and the IIR filter 105 make up the delay locked loop, and by setting a delay quantity of the delay unit 104 to (n+1), timing of the output of the delay unit 104 can be coincided with that of the output of the IIR filter 105 , thereby enabling accurate extraction of a distortion component to be implemented by the subtractor 103 . Further, in contrast to the conventional technology, the delay locked loop is fully digitalized, so that the same is resistant to the effect of noises, and will not be out of sync at the time of no signal because the output of the smoothing filter 107 is retained without being affected by an offset. Furthermore, since the FIR filter is not in use, amplitude characteristic of the loop is theoretically smooth, so that redundant delay can be suppressed to an extremely small magnitude. [0000] Second Embodiment [0040] Next, a second embodiment of the invention is described hereinafter with reference to FIG. 2 . With a configuration shown in FIG. 2 , IIR filters 105 are in use in place of the delay unit 104 in FIG. 1 . A delay comparator 106 outputs a signal according to a delay difference between first input signals Ir, Qr, and output signals If, Qf of the IIR filters 105 . The smoothing filter 107 outputs a signal P corresponding to an output of the delay comparator 106 after removing high-pass random components thereof. The IIR filters 105 represent a filter circuit acting on second input signals Ii, Qi, causing a delay quantity to undergo a change according to the signal P. FIG. 2 shows a case where the IIR filters are provided in two stages, however, it is to be pointed out that the invention is not limited thereto. That is, the IIR filter in one stage may be provided or the IIR filters in not less than three stages (generally, in n-stages) (n: an integer not less than 1). If the IIR filters in the n-stages are provided, the sum of delay quantities of respective element IIR filters in the n-stages are obtained, as If, Qf, from the output terminal of the element IIR filter in the last stage. [0041] The configuration of the present embodiment is not limited to a configuration shown in FIG. 2 , and may include various other variations. For example, FIG. 2 shows the configuration wherein the IIR filters 105 are disposed in front-end stages of a predistortor 101 , however, the present embodiment is not limited thereto, and the IIR filters 105 may be disposed in back-end stages of the predistortor 101 , or some thereof disposed in the front-end stages may be combined with others disposed in the back-end stages such that the IIR filters 105 may be divided in such a way as to be disposed at several locations. [0042] With the present embodiment, a delay quantity along a signal path from the predistortor 101 to a subtractor 103 can be minimized while a variable range of the delay quantity can be rendered wider. Further, in contrast to the conventional technology, the delay locked loop is fully digitalized, so that the same is resistant to the effect of noises, and will not be out of sync at the time of no signal because the output of the smoothing filter 107 is retained without being affected by an offset. Furthermore, since the FIR filter is not in use, amplitude characteristic of the loop is theoretically smooth, so that redundant delay can be suppressed to an extremely small magnitude. [0000] Third Embodiment [0043] Now, a third embodiment of the invention is described hereinafter with reference to FIG. 9 . In FIG. 9 , in stead of using the IIR filters as variable delay elements, use is made of a quantizer 108 for binary-quantizing an output of a smoothing filter 107 , and a 0/1 delay switching unit 109 configured so as to be capable of selecting either 0-sample delay or one-sample delay (selectively switching therebetween) according to an output value of the quantizer 108 . A delay comparator 106 outputs a signal according to a delay difference between signals Id, Qd, corresponding to first input signals Ii, Qi, after delayed, and output signals If, Qf of the 0/1 delay switching unit 109 . The smoothing filter 107 outputs a signal P corresponding to an output of the delay comparator 106 after removing high-pass random components thereof. The quantizer 108 receives the signal P, and executes quantization for binarization of the same, thereby outputting a binary output value (for example, 0 or 1), corresponding to the signal P, to the 0/1 delay-switching unit 109 . The 0/1 delay-switching unit 109 causes a delay quantity of second input signals Ir, Qr, to undergo a change according to a binary input value (for example, 0 or 1) corresponding to the signal P, thereby outputting signals If, Qf. [0044] With the present embodiment, since the delay quantity is insufficient at the time of 0-sample delay, and is excessive at the time of 1-sample delay, switching of the delay quantity is automatically implemented by the sigma-delta modulation that is well known as a feedback operation, so that it is possible to set a delay quantity “a” less than one sample on average. Accordingly, switching of the delay quantity can be executed at a sufficiently high speed in comparison with a signal bandwidth, thereby obtaining an advantageous effect equivalent to that of the first embodiment without use of the IIR filter. [0000] Fourth Embodiment [0045] Now, a fourth embodiment of the invention is described hereinafter with reference to FIG. 3 . The present embodiment is an example of a digital predistortion type transmitter (a transmission system at a wireless base station), to which the delay locked loop according the invention is applied. A transmission signal fed from a controller 300 is processed for coding by a modulator 301 to be subsequently subjected to bandwidth control by a baseband-signal-processing unit 302 , which outputs quadrature IQ signals Ii, Qi to be further processed for compensation of distortion by a predistortion unit 303 to be thereby converted into analog signals by a D/A converter 304 , and an quadrature modulator 305 executes conversion of frequencies thereof into a radio frequency band, whereupon a power amplifier 306 amplifies power, thereby sending out radio waves into the air from an antenna 310 through an antenna sharing unit 309 . For the predistortion unit 303 , use is made of any of the first to three embodiments described in the foregoing, or various variations thereof. In this case, nonlinear distortion occurs to the power amplifier 306 at the time of a large output, which, however, can be deemed equivalent to a case where the nonlinear distortion is superimposed on the output of a linear amplifier 307 . [0046] In order to effectively implement predistortion, it is necessary to accurately cancel out nonlinear characteristics of the power amplifier 306 by accurately grasping an amount of the nonlinear distortion that has occurred. Accordingly, transmission radio waves are converted in frequency to an IF band through a mixer 311 to be subsequently converted into a digital signal by an A/D converter 312 , whereupon the digital signal is demodulated by a digital quadrature demodulator 313 to be thereby fed back to the predistortion unit 303 . As for a configuration of the demodulator, various configurations other than the one described are conceivable for adoption as in the case of the conventional demodulator. [0047] With the present embodiment, the nonlinear distortion that has occurred to the power amplifier 306 can be accurately extracted by applying the delay locked loop according the invention to the digital predistortion type transmitter, so that it is possible to implement compensation for distortion, with few errors. [0000] Fifth Embodiment [0048] Further, a fifth embodiment of the invention is described hereinafter with reference to FIG. 3 . The present embodiment is an example of a wireless base station, to a transmission system of which the digital predistortion type transmitter according to the fourth embodiment of the invention is applied. The present embodiment is the same in configuration as the fourth embodiment except that a signal reception system is connected to the antenna sharing unit 309 . The antenna sharing unit 309 outputs a received signal delivered via the antenna 310 to the signal reception system while receiving a transmission signal amplified in power by the power amplifier 306 of the transmission system, and outputting the transmission signal to the antenna 310 . As for a specific configuration of the signal reception system, various well known forms can be used. [0049] With the present embodiment, because the effect of signal delay is compensated for, and nonlinear distortion can be accurately extracted, control error in adaptive signal processing can be reduced, thereby enhancing linearity. Accordingly, since compensation for nonlinear distortion is appropriately implemented even at the time of a large amplitude, output at a large amplitude is enabled, thereby enabling operation in a high-efficiency state to be implemented.

Disclosed are a delay locked loop circuit capable of accurately extracting nonlinear distortion superimposed on an output of a digital predistortion type transmitter, the digital predistortion type transmitter, and a wireless base station using the same. The delay locked loop circuit comprises a variable delay element for receiving first input IQ signals Ir, Or, a subtractor for receiving signals Id, Qd based on output signals. If, Qf of the variable delay element, and second input IQ signals Ii, Qi, a delay comparator for receiving the output signals If, Qf of the variable delay element, and a smoothing filter for receiving and smoothing an output signal of the delay comparator, and outputting a smoothed signal to the variable delay element, in which delay control is implemented for checking distortion occurring to the output IQ signals due to the same passing through the analog circuit by means of the variable delay element. Either the first input IQ signals or the second input IQ signals are signals generated as a result of output IQ signals Io, Qo undergoing digital-to-analog conversion, and again undergoing analog-to-digital conversion after passing through an analog circuit. In particular, an IIR filter may be used for the variable delay element.

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims benefit of priority to U.S. Provisional Patent Application Ser. No. 60/959,811 filed Jul. 16, 2007 and U.S. Provisional Patent Application Ser. No. 60/923,832, filed Apr. 17, 2007, which applications are hereby incorporated by reference in their entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to surgical methods and devices therefor, including surgical access devices. Particularly, the present invention is directed to surgical access ports for use in endoluminal or transluminal procedures, such as through the human esophagus or lower gastrointestinal tract, and related methods. 2. Description of Related Art A variety of devices are known in the art for assisting surgical procedures-including cannulas for accessing internal cavities of a patient, and other devices, such as endoscopes. Endoscopy is a term for a range of medical procedures that allow a doctor to observe the inside of the body without performing major surgery. An endoscope (e.g., a fibrescope) is a long tube with a lens at the distal end and an eyepiece and/or camera at the proximal end. The end with the lens is inserted into a patient. Light is transmitted through the tube (via bundles of optical fibres) to illuminate the surgical site, and the eyepiece magnifies the area so the doctor can visualize the surgical site. Usually, an endoscope is inserted through one of the body's natural openings, such as the mouth, urethra or anus, but depending on the particular procedure, may require a small incision through the skin. Such procedures are often performed under general or local anesthetic. Specially designed endoscopes are used to perform simple surgical procedures, such as tubal ligation (“tying” of the female fallopian tubes); locating, sampling or removing foreign objects or tumors from the lungs or digestive tract; removal of the gallbladder; taking small samples of tissue for diagnostic purposes (biopsy). A range of endoscopes have been developed for many parts of the body. Each has its own name, depending on the part of the body it is intended to investigate. For example, an arthroscope is inserted through a small incision to examine a skeletal joint. A bronchoscope is inserted down the trachea (windpipe) to examine the lungs. A colonoscope is inserted through the anus to examine the colon. A gastroscope is inserted down the esophagus to examine the stomach. A hysteroscope is inserted through the cervix to examine the uterus. A laparoscope is inserted through a small incision to examine the abdominal organs. A cystoscope is inserted via the urethra to examine the urethra and urinary bladder. Many of the foregoing procedures can be carried out with one or more instruments used in conjunction with an endoscope. Such procedures often also require an opening through which the endoscope and/or instruments can pass. Such working channels can be natural openings—e.g. the mouth and esophagus, or artificial openings such as an incision made in the abdomen of a patient. Applicants recognize that current endoscopic systems suffer from various limitations, particularly when used in conjunction with certain medical procedures. Some endoscopes may be configured with an integral working channel. Such working channels are often small, and may or may not be suitable for a particular instrument to be inserted therethrough. Moreover, it can prove difficult to obtain good working instruments in very small sizes. Further, imaging through fibers can be limiting-often due to low resolution images. If an endoscope is provided with an imaging chip on a scope having a circular cross-section, this can restrict the size and quality of images obtained therefrom. Moreover, if insufflation is required for a particular procedure, insufflation through an endoscope is typically maintained with mechanical seals. Even state-of-the-art mechanical seals typically present difficulty for a surgeon due to substantial friction, which results in difficult manipulation and restricted instrument access. Applicants recognize that with the foregoing problems in the art, there remains a need for improved visualization and access devices that allow for easier access and movement and better quality imaging. The present invention provides a solution for these problems. SUMMARY OF THE INVENTION The purpose and advantages of the present invention will be set forth in and apparent from the description that follows. Additional advantages of the invention will be realized and attained by the devices and methods particularly pointed out in the written description and claims hereof, as well as from the appended drawings. The present invention is directed to devices, as described hereinbelow, as well as to methods utilizing such devices. To achieve these and other advantages and in accordance with the purpose of the invention, as embodied, the invention includes an access device adapted and configured to be inserted through a natural biological orifice is provided. The access device includes a body, a nozzle means and means for delivering a pressurized flow of fluid to the nozzle means. The body is configured and dimensioned to be inserted through a natural bodily orifice and has proximal and distal end portions and defines at least one lumen therethrough to accommodate passage of one or more surgical instruments. The nozzle means is operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough. In accordance with the invention, the body can be substantially rigid or substantially flexible, or include both rigid and flexible elements, as required. The access device can include at least one control element for manipulation of the curvature of the access device. Alternatively, two individual control elements can be used to control orthogonal motion—e.g., with respect to X and Y axes. Such control elements can further be provided in one or more opposing pairs. Such control elements can be, for example flexible or semi-rigid rods, wires or ribbons. Manipulation of the curvature of the entire access device can be controlled, or alternatively, the curvature of only the distal tip can be controlled, depending on the precise implementation. One or more image sensors can be arranged in the distal end portion of the access device, which are adapted and configured to capture images of a region distal the distal end portion of the access device. If multiple image sensors are provided, they can facilitate stereoscopic imaging of the subject region. One or more working channels can be provided in the wall of the access device, and one or more of said working channels can be configured and adapted to provide irrigation to a surgical site. Alternatively or additionally, one or more of said working channels can be configured and adapted to provide drainage to a surgical site and one or more channels can be configured to allow a surgical instrument to pass therethrough. One or more light sources can be arranged in the distal end portion of the access device, and adapted and configured to illuminate a region distal the distal end portion of the access device. Alternatively or additionally, illumination means can be provided in the wall of the access device. Further, one or more guide elements adapted and configured to guide surgical instruments in the lumen of the access device can be provided. One or more pressure sensing channels can be arranged in the wall of the access device, and be configured and adapted to be in fluid communication with a surgical site. Devices in accordance with the invention can be of any length desired or required. For example, the length of the body can be between about 30 cm and about 50 cm, depending on the precise application. A range of length between about 30 cm and 40 cm is particularly advantageous for a transesophageal access route for an endoluminal intra-gastric procedure—accessing a patient's stomach or duodenum. In alternate embodiments, the length of the body can be between about 40 cm and 50 cm, which range of length is particularly advantageous for transluminal access to internal organs via a trans-gastric route—that is, accessing a an organ through the wall of a patient's stomach. If desired, devices in accordance with the invention can be in the range of about 15 cm to about 20 cm for use as an anoscope and transanal access to the rectum, and can be up to about 160 cm in length for use as, or in conjunction with, a colonoscope, depending on the precise implementation. In accordance with one embodiment of the invention, a device provided with integral optics and illumination is between about 90 cm and 130 cm in length, preferably about 110 cm in length. Internal diameters of access devices in accordance with the invention can be any size that is practical for the application, but preferably range between about 10 mm and 20 mm, and in a preferred embodiment, between 15 mm and 18 mm. Access devices in accordance with the invention can further comprise an integral image display provided in the proximal end portion thereof. In accordance with another aspect of the invention, an insertion device is provided for inserting access devices in accordance with the invention. Such insertion devices can have a tip portion to facilitate insertion of the access device through a natural orifice. The tip can taper to a substantially blunt end and/or can include a dilating element. The tip portion can include at least one transparent region. The insertion device can be provided with illuminating means for illuminating a region distal the insertion device. Also, the insertion device can be configured and adapted to interface with an endoscope to facilitate guidance of the user during insertion. The insertion device can further include an integral lens arranged in a distal end portion thereof. Further in accordance with the invention, a method of accessing an internal region of a body is provided. The method includes inserting through a natural body orifice an elongated body having longitudinally opposed proximal and distal end portions. The body defines at least one lumen configured and dimensioned to accommodate passage of one or more surgical instruments. The body further includes nozzle means operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough. The method further includes the steps of delivering pressurized fluid to the nozzle means to create said pressure differential; and inserting one or more surgical instruments through the body to access the interior of the body. In accordance with another aspect of the invention, an access device is provided which is adapted and configured to be inserted through an orifice. The access device includes a body, a nozzle means, means for delivering a pressurized flow of fluid to the nozzle means and at least one control element. The body is configured and dimensioned to be inserted through an orifice and has proximal and distal end portions and defines at least one lumen therethrough to accommodate passage of one or more surgical instruments, and is flexible in at least one region. The nozzle means is operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough. The at least one control element is arranged within the body and is adapted and configured to effect a change in curvature of the at least one flexible region of the body. In accordance with the invention, the orifice can be a natural biological orifice, or alternatively can be formed from an incision made in the patient. In accordance with still another aspect of the invention, a method for performing a cholecystectomy is provided. The method includes the steps of inserting a first access device through the esophagus of a patient and into the stomach, penetrating the stomach wall and extending the first access device through the stomach wall, inserting a second access device through the umbilicus of the patient, inserting an endoscope through the first access device, retracting the gallbladder, exposing the cystic duct and cystic artery, applying at least two dips on each of the cystic duct and artery, transecting each of the cystic duct and artery, dissecting and removing the gallbladder from the liver bed, and removing the gallbladder. It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the method and system of the invention. Together with the description, the drawings serve to explain the principles of the invention, wherein: FIG. 1 a illustrates a first embodiment of an access device in accordance with the invention, having a generally elliptical cross-section; FIG. 1 b is a proximal end view of the embodiment of FIG. 1 a; FIG. 1 c is a distal end view of the embodiment of FIG. 1 a; FIG. 2 a illustrates a further embodiment of an access device in accordance with the invention, in which the wall of the device houses additional working channels; FIG. 2 b is a cutaway view of a portion of the access device of FIG. 2 a , illustrating a fluid seal in accordance with the invention; FIG. 2 c is a distal end view of the embodiment of FIG. 2 a , illustrating working channels and other features; FIG. 3 a illustrates an access device in accordance with the invention, which is flexible and manipulable, in which instrument guides can be provided integrally with the access device, or can be provided in an attachable cap; FIG. 3 b is a partial view of the access device of FIG. 3 a , illustrating surgical instruments inserted through the access device; FIG. 3 c is a proximal end view of the access device of FIG. 3 a , illustrating an instrument guide provided therewith; FIG. 3 d is a partial view of the distal end of the access device of FIG. 3 a , illustrating an insertion device inserted therethrough; FIG. 4 a illustrates an access device in accordance with the invention having a proximal display, such as an LCD display; FIG. 4 b is a distal end view of the access device of FIG. 4 a; FIG. 5 illustrates a further embodiment of an access device in accordance with the invention, including control knobs which manipulate control elements provided within the access device; FIG. 6 is an enlarged cross-sectional view of a distal end portion of an access device in accordance with the invention, through which an insertion device has been inserted; FIG. 7 a illustrates a flexible access device, that is particularly configured and adapted for transanal insertion; FIG. 7 b illustrates a rigid access device that is particularly configured and adapted for transanal insertion; FIG. 7 c is a distal end view of the access devices of FIGS. 7 a and 7 b; FIG. 7 d is a proximal end view of the access devices of FIGS. 7 a and 7 b , illustrating instrument guides provided thereon. FIG. 8 is a side view of a further embodiment of an access device constructed in accordance with the invention having a distal end with open distal side portion; FIG. 9 is an illustration of the access device of FIG. 8 inserted through a patient's esophagus into the stomach; FIG. 10 is a side view of another embodiment of an access device constructed in accordance with the invention, with a distal end having a side-grasping feature with undulating grasping elements; FIG. 11 is a partial view of the distal end of a variation of the embodiment of FIG. 10 , with straight grasping elements; FIG. 12 illustrates three stages of an example procedure utilizing the access device of FIG. 10 ; FIG. 13 a is a partial view of the distal end of a further embodiment of an access device constructed in accordance with the invention having internal steering elements; FIG. 13 b is a cutaway view of the distal end of the access device of FIG. 13 a; FIG. 14 is a schematic representation of a cholecystectomy in accordance with the invention; and FIG. 15 are side and end views of a frangible tip in accordance with the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Reference will now be made in detail to select embodiments of the invention, examples of which are illustrated in the accompanying drawings. The devices and methods presented herein may be used as surgical access ports, particularly for endoluminal or transluminal medical procedures. The devices described and set forth herein can incorporate any feature from the following U.S. patent applications and patents, which are each incorporated herein by reference in their entirety: U.S. patent application Ser. No. 11/517,929, filed Sep. 8, 2006 (U.S. Patent Publication No. US 2007/0088275, published Apr. 19, 2007), which is a continuation-in-part of U.S. patent application Ser. No. 10/776,923, filed Feb. 11, 2004 (now U.S. Pat. No. 7,338,473), which is a continuation-in-part of U.S. patent application Ser. No. 10/739,872, filed Dec. 18, 2003 (now U.S. Pat. No. 7,285,112), which is a continuation-in-part of U.S. patent application Ser. No. 10/441,149, filed May 17, 2003 (now U.S. Pat. No. 7,182,752). Each of the foregoing applications also claims priority to U.S. Provisional Application Ser. No. 60/461,149, filed Apr. 8, 2003, which itself is also hereby incorporated by reference in its entirety. The devices described and set forth herein can further incorporate any feature from U.S. patent application Ser. No. 11/544,856 (U.S. Patent Publication No. US 2008/0086167), and U.S. Provisional Application Ser. No. 60/850,006 both filed Oct. 6, 2006, which are also incorporated herein by reference in their entirety. FIGS. 1 a - 1 c illustrate a first embodiment of an access device 100 in accordance with the invention. This embodiment has a generally elliptical cross-section, as can be seen at its proximal end 101 ( FIG. 1 b ). Further, this access device 100 , as embodied in FIGS. 1 a - 1 c , is sufficiently flexible to navigate a natural body orifice through which it is intended to be inserted. The access device 100 includes an insufflation input 120 a , and a pressure sensing channel having proximal and distal openings 110 a , 110 b , respectively. The body of the access device 100 includes a lumen 170 , and can be embodied so as to include manipulating elements 180 , such as wires, to effect curvature of the access device 100 , when desired. An image sensor 130 may be provided at the distal end region, as may be at least one light source 140 . In this embodiment it is contemplated that the at least one light source, may be one or more light-emitting diodes (LEDs), and that one or more CMOS, CCD or other small image sensors may be mounted at the distal end of the device and used as image sensors. Images can be transmitted to the external environment through conductive elements provided on or within the access device 100 , or can be provided wirelessly, such as by radio frequency transmission to a receiver. Alternatively, it is contemplated that the access device might not contain integrated optics and that known types of viewing devices may be inserted through the central lumen or a working channel of the access device for viewing purposes. Devices in accordance with the invention can be of any length desired or required. For example, the length of the body can be between about 30 cm and about 50 cm, depending on the precise application. A range of length between about 30 cm and 40 cm is particularly advantageous for a transesophageal access route for an endoluminal intra-gastric procedure. In alternate embodiments, the length of the body can be between about 40 cm and 50 cm, which range of length is particularly advantageous for transluminal access to internal organs via a trans-gastric route—that is, accessing a an organ through the wall of a patient's stomach. If desired, devices in accordance with the invention can be in the range of about 15 cm to about 20 cm for use as an anoscope and transanal access to the rectum, and can be up to about 160 cm in length for use as, or in conjunction with, a colonoscope, depending on the precise implementation. In accordance with one embodiment of the invention, a device provided with integral optics and illumination is between about 90 cm and 130 cm in length, preferably about 110 cm in length. Internal diameters of access devices in accordance with the invention can be any size that is practical for the application, but preferably range between about 10 mm and 20 mm, and in a preferred embodiment, between 15 mm and 18 mm. Additional features that can be incorporated into access devices in accordance with the invention include, but are not limited to having an outer cross-sectional shape ranging from circular, through an elliptical shape to near linear in shape. With respect to the embodiment of FIGS. 1 a - 1 c , one or more fluid seals 120 b are provided to seal between instruments passing through the lumen 170 , and the wall of the lumen, in order to maintain pressure within an operative space. Various embodiments of access devices having fluid seals (or alternatively “air seals” or “pneumatic seals”) are set forth in the documents referenced above. Although mechanical sealing can additionally be incorporated into different embodiments of access devices described therein, as well as into those described in connection with the present invention, such mechanical seals can equally be absent, allowing substantially unencumbered movement of instruments through and within such access devices. In accordance with the present invention the access device 100 of FIG. 1 or any access device set forth herein can be provided with a fluid seal, as described in the documents referenced above. The subject access devices can further include one or more of the following features: one or more endoscopes; one or more working channels; illumination capability; and/or the capability to be steered by a user. Incorporation of non-mechanical seals into endoluminal and transluminal access devices in accordance with the invention can allow for easier, safer procedures as well as new approaches to procedures. Fluid seals in accordance with the invention can be embodied in a variety of suitable manners. Nozzles can be provided that are substantially annular in configuration, or alternatively, if desired, a plurality of discrete nozzle apertures can be defined in place one such annular nozzle. These discrete nozzle apertures can be arranged as necessary, about the wall of the access device, to form an effective barrier to proximal egress of insufflation gas from a surgical site. Such discrete nozzles can each be substantially round in shape, or alternatively can be oblong or another shape. The nozzles can be placed at regular intervals about the circumference of the lumen, can extend part way around, or can be spaced from each other in groups. If turbulence is desired, surface features such as protrusions, vanes, grooves, surface texture can be added in the path of fluid flow, as desired. Further, one or more nozzles or groups of nozzles can be provided in access devices in accordance with the invention, with such nozzles being located in one region, or in a plurality of regions along the length of the access device. FIGS. 2 a - 2 c illustrate a further embodiment of an access device 200 , in accordance with the invention. The access device 200 includes an insufflation fluid input 220 a , which is in fluid communication with a fluid seal 220 b . The fluid seal may be positioned within the proximal housing of the device or may be positioned at any desired location between the proximal housing and the distal tip of the device. A lumen 270 serves as a working channel for passage of surgical instruments and the like, and is defined by the wall 275 of the access device 200 . The wall 275 itself also houses additional working channels, such as an irrigation port 260 , drainage port 261 and pressure sensing port 210 a . Additional ports can be used for additional functions, as desired or required. Optionally, illumination can be provided by way of one or more light sources, which can be provided directly in the wall 275 , or whose light can be transmitted through the wall 275 , to the distal end thereof by one or more fiber optic elements 250 . Further, one or more optional image sensors 230 can be provided in the wall 275 in order to capture images of a surgical site. In accordance with the invention, the foregoing and following embodiments can be flexible or rigid, as desired or required. Further the foregoing and below-described access devices allow a user to pass a plurality of surgical instruments through a natural lumen into the human body. Such natural openings include, for example, the mouth and esophagus, the anus and rectum or vagina. Entrance through such natural openings can provide access into the digestive tract without surgical incisions penetrating the external abdominal wall. Furthermore, gastrointestinal pressures can be maintained within the organ(s), such as the stomach, without any interference with inserted instruments which would typically be caused by mechanical seals used in a typical endoscope, colonoscope, trocar, cannula or other access systems. Moreover, manipulation of surgical instruments is less encumbered, as compared with more conventional devices having mechanical seals. The subject access devices suffer less from frictional resistance between inserted instruments and the access device. Reducing such interference and friction is advantageous, and may reduce torque and other forces transmitted from the inserted instrument through the access device to surrounding tissue, which can cause trauma and prolong healing and recovery. The access device may also allow crossing of paths of the inserted instruments, as when switching hands, without having to retract and then reinsert an instruments. Endoscopic surgical or exploratory access via a transesophageal or transanal route can be intraluminal—that is, it can be used for accessing the natural lumen itself (e.g., the esophagus, stomach, rectum, colon), or can be transluminal, that is—used to access other anatomy through the wall of such structures. Such an approach can be referred to as Natural Orifice Transluminal Endoscopic Surgery™ (“NOTES”). Such access can allow for imaging, insertion of one or more surgical instruments, removal of a tissue specimen, or insufflation of the lumen (e.g., the stomach). For example, access to a patient's peritoneum can be achieved through an internal endoluminal route. Moreover, insufflation of the peritoneum is possible using access devices in accordance with the invention. The following is a sample list of minimally-invasive procedures that can be accomplished by surgeons operating through access devices as described herein: Endoluminal Access to the Upper GI Tract Reflux procedures, such as fundoplication Obesity procedures, such as gastric restriction Diabetes procedures such as duodenal bypasses Gastric tumor removal Endoluminal Access to the Lower GI Tract Tumor removal Diverticulum removal, repair Transluminal Access Through Esophagus, Rectum or Vagina All current abdominal and pelvic surgery such as: Gallbladder Appendectomy Ovarian cysts Oophorectomy Sterilization Hernia repair Devices in accordance with the invention can allow, in general, for new approaches to accessing anatomy. Any instrument inserted through the lumen of an access device equipped with one or more fluid seals in accordance with the invention will experience markedly reduced frictional resistance, due to replacement of mechanical seals with fluid seals. It may, at times, prove useful to include one or more mechanical valves, such as for example a duckbill valve or other so-called “zero seal” intended to seal the access device when no instrument is inserted therethrough. However, typically the number of such valves will be reduced if not eliminated, for every fluid seal that is used. Without mechanical seals protruding into a lumen of access devices in accordance with the invention, more space for instruments is available, while free insertion and movement of the instruments is not hampered by mechanical seals. Further, gas, such as carbon dioxide, can be supplied to such fluid seals in a continuous manner—thereby insufflating an operative space while also sealing the operative space. Such a continuous flow of insufflation gas is distinct from prior systems, in that prior insufflation technologies operate in a cyclic manner—alternately insufflating and sensing pressure. Such systems do not allow for insufflation when pressure is being sensed. A further advantage to access devices in accordance with the invention, is that maintaining a pressure barrier in an access device, between an insufflated space and the surrounding environment without the use of elastomeric seals provides the capability for safe relief from pressure buildup from any possible system failures or sources of additional pressure. Additionally, bucking is reduced when operating using devices in accordance with the invention. Bucking is the phenomenon where a patient tightens his diaphragm while his abdomen is insufflated. This tightening dramatically increases pressure within the abdomen. Further, if used in laparoscopic procedure, fluid seals incorporated with devices constructed in accordance with the invention all use of open type instrumentation. Additionally, access devices in accordance with the invention allow for more freedom in instrument design. Because contact seals are not required, instruments inserted through access devices in accordance with the invention do not need to conform to the shape and size of such mechanical seals. Accordingly, instruments having a non-symmetrical shape can be used, which may be more efficient and cost-effective, and multiple instruments can be inserted simultaneously to improve manipulation through the access device. Advantageously, the absence of mechanical seals reduces the likelihood of smudging of optical components of surgical instruments inserted through access devices constructed in accordance with the invention. Moreover, devices in accordance with the present invention can be provided with various cross-sectional shapes, including, but not limited to circular, elliptical, or as set forth above, cross-sectional shapes that approach a linear morphology when not in use. If embodied in an elliptical shape, access devices in accordance with the invention advantageously allow insertion of instruments of various sizes, such as instruments having an oblong cross-section. An elliptical cross-section can also allow for insertion of the access device in regions of the anatomy that would otherwise not allow insertion of an access device having a round cross-sectional shape. Surgical instruments that can be used through access devices in accordance with the invention include, but are not limited to rigid or flexible versions of the following, depending on the procedure: graspers, scissors, snares, staplers, ultrasonic imaging devices, ultrasonic cutting and/or coagulating devices, vessel sealing devices, RF devices, microwave energy delivery devices glue delivery devices and suturing devices. Access devices in accordance with the invention can further incorporate various imaging technologies. One or more image sensors can be utilized for image acquisition, which sensors can be incorporated into an access device, for example at or near the distal end thereof. Alternatively, standard fiber optic imaging technology may be inserted through the fluid seal or may be incorporated into a wall of the access device, such that an objective (lens) is at the distal end portion of the access device, and an image sensor and/or eyepiece is provided elsewhere, such as at the proximal end thereof. Such imaging devices can be embodied so as to obtain still images, but video images can alternatively or additionally be obtained to allow for real-time guidance of a procedure, and can allow for guidance during insertion of the access device itself. Additionally, illumination can be provided in the subject access devices in the form of integrated fiber-optics, connected to an external light source and/or integrated sources of light, such as LEDs (light-emitting diodes) integrated into the distal end portion of the access device. Capability for infrared imaging for diagnostic purposes can further be provided, in the form of an optical sensor capable of capturing light in the infrared region, and additionally, if needed, an infrared light source. FIGS. 3 a - 3 d illustrate a surgical access device 300 in accordance with the invention, which is flexible and manipulable, as with foregoing embodiments. One or more fluid seals 320 b are provided therein, to which fluid (such as compressed air or inert gas, or in the case of arthroscopic or other surgery which utilizes liquid, saline or other suitable biocompatible liquid) is supplied via a fluid input 320 a . A sensing input 310 is also provided, as described above in connection with other embodiments. If desired, instrument guides 385 (shown in the end view of FIG. 3 c ) can be provided integrally formed with the access device 300 , or in the form of an attached cap 380 ( FIG. 3 a ). As shown in FIG. 3 b , surgical or exploratory instruments 305 a , 305 b , 305 c pass through the guides 385 , and thereby are prevented from moving undesirably, or unnecessarily interfering with one another. Further in accordance with the invention, an insertion device 390 can be provided, which is inserted into the access device 300 , prior to insertion in a patient. The insertion device 390 includes a tip 395 , which facilitates insertion into a patient. Tip 295 may be blunt or sharp, rounded or pointed or such other configuration as appropriate for the intended insertion. Tip 395 also may be transparent to provide optical viewing during or after insertion. As illustrated in FIG. 4 a , a proximal display 489 , such as an LCD display, can be provided with access devices in accordance with the invention, such as access device 400 of FIGS. 4 a and 4 b . Such displays 489 can be integrated with respective access devices, or can be attached thereto in order to provide optimum viewing nearer the location in which the procedure is taking place, rather than on a display mounted far from the operating table. Such displays can provide high resolution direct images of the anatomy. In the embodiment of FIGS. 4 a and 4 b , the display 489 receives images from an image sensor 430 arranged in the distal end region of the access device 400 . If desired, video signals from the image sensor 430 can be additionally output to display monitors by one or more wired and/or wireless connections. Of course, images may alternatively or additionally be displayed on a traditional monitor in the vicinity. As best seen in FIG. 4 b , illumination elements 451 may also be provided at the distal end region of the access device 400 , and can include light sources, such as light-emitting diodes (LEDs) or alternatively or additionally, fiberoptic conduits that deliver light from an external light source. It is preferable, generally, that such illumination elements 451 be capable of providing bright, controllable illumination and be relatively small in size. As can be seen in FIG. 4 b , the foregoing elements can be provided directly in a wall of the access device 400 , which has a lumen 470 , running therethrough, with openings 470 a ( FIG. 4 a ), 470 b at proximal and distal ends of the access device 400 , respectively. The nature of access devices in accordance with the invention, particularly because fluid seals can be integrated therewith, allows the ability to use new flexible instruments of different shapes, geometries and mechanics. Such instruments might otherwise not be satisfactorily sealable with conventional sealing techniques. The absence of mechanical seals also can allow for passage of instrument drive and steering mechanisms, as well as for tissue manipulation, repair and/or retrieval. FIG. 5 illustrates a further embodiment of an access device 500 in accordance with the invention. The access device 500 includes control knobs 581 , 583 , which manipulate control elements provided within the access device 500 . When the control elements are placed in tension, the access device will tend to bend toward that control element. Conversely, when a control element is placed in compression, the access device 500 , will tend to bend away from that control element. In the embodiment of FIG. 5 , two controls 581 , 583 control bending of the access device in two orthogonal directions, such as “X” and “Y” in a Cartesian coordinate system. FIG. 6 is an enlarged cross-sectional view of a distal end portion of an access device 600 , in accordance with the invention, through which an insertion device 660 has been inserted. The insertion device 660 may receive an endoscope 670 therethrough, which views the insertion site through one or more transparent windows or lenses 665 . The lenses 665 can also be adapted to provide illumination to the insertion site. In this embodiment, the insertion device 660 may terminate in an elongate tip 661 , which may facilitate dilation of a natural orifice through which the insertion device 660 and access device 600 assembly pass during insertion. Further, the contour 663 of the insertion device provides a relatively smooth transition to the diameter of the access device 600 from that of the tip 661 . FIGS. 7 a - 7 d illustrate rigid and flexible access devices 700 a , 700 b , respectively, that are particularly configured and adapted for transanal insertion into the rectum of a patient. Features for these embodiments can be any of those set forth in connection with foregoing embodiments, including but not limited to use with an insertion device, incorporation of one or more fluid seals or insufflation means and/or steerability (in the case of flexible access devices). Further, as illustrated in FIG. 7 d , which is a proximal end view of a cap for attachment to the access device 700 a , 700 b , instrument guides 785 can be provided. As best seen in the distal end view of FIG. 7 c , irrigation channels 781 , illumination capability 783 , visualization components, such as one or more image sensors 787 , or fiber optics to allow image transmission, and drainage capacity, such as in the form of drainage channels 789 can be incorporated. The foregoing elements can be arranged within the wall 775 of the access devices 700 a , 700 b , as with the embodiment described in connection with FIGS. 2 a - 2 c , for example. Additionally, an insertion device 790 can be utilized to facilitate insertion into the body of a patient. FIG. 8 is a side view of a further embodiment of an access device 800 constructed in accordance with the invention. The access device 800 has a distal end 870 with open distal side portion 875 . This embodiment allows instrumentation to be oriented to act on the side as an alternative to or in addition to through a distal end aperture. This arrangement is particularly advantageous when performing a procedure on the wall of a passage, such as the esophagus, stomach or duodenum, for example. A wall of such passage can be sucked via vacuum or pulled by mechanical means into contact with the access device 800 to facilitate a procedure. When in contact with the access device 800 , steps including cutting, stapling and removal of tissue can be carried out. Vacuum can be applied in a number of ways, in accordance with the invention. Preferably, suction is applied directly through the access device 800 . A single pump can be provided, which is adapted and configured to both provide insufflation pressure to the access device 800 and to provide suction to the access device 800 . Use of a single pump allows for more streamlined surgical equipment and controls—reducing unnecessary clutter in the operating room and reducing cost by obviating a second pumping device. Naturally, if desired, separate pumps can be connected to the access device 800 , and selectively activated in order to switch between insufflation and suction. Alternatively still, a secondary suction device can be utilized—either inserted through a central internal lumen of the access device 800 or external thereto. Additionally, the access device 800 can be flexible to allow manipulation through the anatomy of a patient, as seen in FIG. 9 . Moreover, the overall shape of the access device 800 can be preformed, as illustrated, so that the device has a tendency to revert to a shape that facilitates insertion and/or comfortable retention in the patient. The entire access device 800 , or a portion thereof, such as the distal end portion, can be steerable to aid insertion of the access device and procedures performed therewith. A fluid seal can be provided in the proximal end portion 815 of the access device 800 , or additionally or alternatively at one or more other locations throughout the length of the access device 800 . FIG. 10 is a side view of another embodiment of an access device 1000 constructed in accordance with the invention. The access device 1000 is similar to that of FIGS. 8 and 9 , but includes at its distal end 1070 , a side-grasping feature with undulating grasping elements 1071 . Alternatively, the side-grasping elements can be straight grasping elements 1171 as illustrated in FIG. 11 . FIG. 12 illustrates the side grasping elements in closed, open and grasping positions, respectively. The grasping elements can be used to engage a wall of a passage, internal organ or other element, for example, to move the wall or steady the wall for another step, such as a puncture or incision. Actuation can be effected in any suitable manner. In accordance with one aspect of the invention, tension within the wall 1079 of the distal end 1071 is adjusted to effect closure or opening of the grasping elements 1071 . Such tension can be adjusted by way of, for example, shape-memory alloy ribs 1278 arranged within the wall of the distal end 1070 . Such ribs 1278 can have a first shape at normal room and/or body temperatures. The ribs 1278 can be electrically connected to a power source, such that when voltage is applied, resistive heating of the ribs 1278 effects a change in shape of the ribs to a second shape. Depending on the desired implementation, the normal state of the ribs can be open or closed. Alternatively, the grasping elements 1071 can be actuated by providing one or more control elements (e.g., wires) terminating in a plurality of ends that terminate in or near the grasping elements 1071 , within the wall 1079 of the distal end 1071 . Accordingly, applying compression to such control cables will cause the grasping elements to close. FIGS. 13 a and 13 b illustrate a distal end portion 1370 of a surgical access device constructed in accordance with the invention having a steerable distal end portion 1370 . Control elements 1310 , such as wires are provided within or adjacent the wall 1379 of the access device. The control elements 1310 are anchored in one or more locations 1320 to the wall of the access device. Although illustrated within the lumen 1340 of the access device, the control elements 1310 are provided with in the wall 1379 . Tension applied to one or more control elements 1310 effects a change in curvature of the distal end portion 1370 . In conjunction with applied rotation to the entire access device by a surgeon, navigation through the patient's anatomy is facilitated. The present invention also relates to surgical procedures performed utilizing devices set forth herein. FIG. 14 illustrates an endoluminal and transluminal access device 1400 being used in a trans-gastric cholecystectomy (removal of gall bladder). As illustrated, the access device 1400 is inserted by way of the esophagus 1490 of a patient, into the stomach 1420 of the patient. Access is made by way of an incision through the wall of the stomach 1420 , into the abdominal cavity 1410 . An incision is made in any suitable manner, but preferably by an endoscopic cutting implement placed through the lumen of the access device 1400 , which induces coagulation, such as by electrocautery or ultrasonic vibrations. Either preceding or following this step, a second access device 1450 is inserted through the navel or umbilicus 1411 of the patient. This mode of external access obscures any scarring that may occur. Naturally, the trans-esophageal entry of the access device 1400 carries no risk of visible scarring. Prior to or upon entering the abdominal cavity 1410 , the cavity may be insufflated by way of the access device 1400 . Alternatively, the abdominal cavity can be insufflated by way of the second access device 1450 and/or still another element, such as a veress needle. In the illustrated embodiment, a flexible endoscope 1405 is inserted through the transluminal access device 1400 . Any number of additional instruments that can physically fit through the lumen of the access device 1400 can be inserted therethrough, and the fluid seal formed by the access device 1400 will maintain a seal around the instruments. An entire cholecystectomy can be performed via this access device 1400 . At present it is more effective to close the incision made in the stomach wall by accessing the stomach 1420 from the outside, and for this reason, the second access device 1450 is used with a surgical stapler 1457 to close the incision made in the stomach. Therefore, the second access device 1450 is also used during the cholecystectomy. Through the channel of the second access device, an endoscope, grasper shears or any other necessary instrument can be inserted. Upon severing the cystic duct, vascular tissue and connecting tissue, the gall bladder can be removed by either the transluminal access device 1400 or the second access device 1450 . If necessary, the gall bladder can be separated into smaller pieces for removal, as by a morcellator or the like. In accordance with one embodiment of the invention, a method for performing a cholecystectomy includes the steps of: Inserting a first access device in accordance with the invention through the esophagus of a patient and into the stomach; Penetrating the stomach wall and extending the first access device through the stomach wall; Inserting a second access device through the umbilicus of the patient; Inserting an endoscope through the first access device; Retracting the gallbladder with the at least one grasper; Exposing the cystic duct and cystic artery; Applying at least two clips on each of the cystic duct and artery; Transecting each of the cystic duct and artery with surgical scissors or another suitable instrument; Dissecting and removing the gallbladder from the liver bed; and Removing the gallbladder. In accordance with this method, the second access device can have, for example, a diameter of 21 mm. The endoscope can be flexible and can have a diameter, for example, of about 10 mm. The cystic duct and artery can be exposed with dissectors, such as 5 mm dissectors. One or more graspers can be inserted through the second access device to manipulate the gallbladder. Clips can be applied with a 5 mm clip applier. The scissors can be 5 mm scissors, for example. Dissecting and removing the gallbladder can be accomplished with shears, such as ultrasonic shears. The gallbladder can be removed through the second access device. Alternatively, the gallbladder can be removed from the first access device, and can be removed from either access device whole or morcellated. FIG. 15 illustrates one embodiment of a distal end portion of an access device in accordance with the invention. The access device of FIG. 15 includes a frangible tip 1510 that maintains sterility of the lumen of the access device during insertion through a cavity, such as the gastrointestinal tract, until a point when the tip is ruptured or intentionally cut. The frangible tip may have any shape, and may include lines of weakness 1513 , such as regions of decreased material thickness or score lines. Having a sealed tip, instruments, such as endoscopes inserted through the access device benefit from a sterile path essentially the entire way to the surgical site. This reduces or eliminates any problems in sterilizing equipment, such as endoscopes with working channels. Advantageously, utilizing access devices in accordance with the invention eliminates the need for using endoscopes with integral working channels, because instruments can be inserted in parallel with the endoscope while maintaining a seal around all instruments. Even though sterility using access devices in accordance with the invention is enhanced as compared with simply inserting such instruments through a particular bodily opening, by including a sealed tip, sterility of a working channel is further enhanced. Other types of tips or seals can be provided at the distal end of access devices in accordance with the invention, such as a removable cap, a sheath capable of being remotely withdrawn proximally, away from the distal tip or hinged hemispheric shutters, that function similarly to an eyelid and close over the distal opening of the lumen. In accordance with the invention, transluminal access can be made through the rectum, colon, stomach (as illustrated in FIG. 14 ), esophagus or vagina, for example. Instruments that can be inserted through access devices in accordance with the invention include, but are not limited to dissectors, clip appliers, shears, automatic suturing devices, endoscopes, graspers, morcellators, suction tubes, electrocautery or coagulation devices, specimen retrieval tools, surgical staplers, as well as specialized tools for specific procedures. Surgical procedures which may be performed with devices set forth herein, and in accordance with methods set forth herein include: cholecystectomy, appendectomy bariatric procedures, such as adjustable gastric banding (lap band), gastrectomy, such as sleeve gastrectomy, any of a variety of procedures to alleviate gastroesophageal reflux disease (GERD), tubal ligation, oophorectomy, nephrectomy, prostatectomy, colorectal procedures, hernia repair, gynecological resection, resection of the spleen, and splenectomy. Such procedures, as well as others applicable in accordance with the invention, can mitigate damage caused by or aide recovery from such conditions as obesity, diabetes, gastroesophageal reflux disease (GERD), gallstones, appendicitis, colon disease, ideopathic thrombocytopenia purpura (ITP) and other diseases. It should be noted that features described and/or illustrated in connection with one embodiment described herein can be combined with or substituted for other features described and/or illustrated in connection with any other embodiment set forth herein. Although a feature may be described in one particular embodiment, it should be understood that such a feature is not limited to being provided precisely in that manner or only in that embodiment. The access devices and related methods of the present invention, as described above and shown in the drawings, provide, among other things, access devices with superior properties including the capability to provide substantially frictionless sealing of instruments passing therethrough. Endoluminal and transluminal procedures advantageously require less time for recovery than traditional procedures, among other benefits. It will be apparent to those skilled in the art that various modifications and variations can be made in the device and method of the present invention without departing from the spirit or scope of the invention.

An access device adapted and configured to be inserted through a natural biological orifice, and related surgical methods are provided. The access device includes a body, a nozzle means and means for delivering a pressurized flow of fluid to the nozzle means. The body is configured and dimensioned to be inserted through a natural bodily orifice and has proximal and distal end portions and defines at least one lumen therethrough to accommodate passage of one or more surgical instruments. The nozzle means is operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough.

BACKGROUND OF THE INVENTION This invention relates to a positioning gear for moving a load suspended by at least one cable of a lifting system in the vertical direction. In building large structures it is generally necessary to position large, complex and heavy members of the total structure by means of a hoisting crane, after which these structural members can be installed. In this process it is up to the crane driver to position the member as well as possible. However, since the crane driver is usually at a great height above the installation level, it is in practice not feasible for him to determine the correct position, in particular the correct height, of the member with respect to the structure. He usually receives, therefore, directions from an assistant at installation level, and generally the positioning of the structural member at installation level is carried out using manual force. This is time-consuming and requires manpower, and is therefore expensive. SUMMARY OF THE INVENTION It is now an object of the invention to permit an assistant at installation level to carry out all the positioning operations as soon as the crane driver has brought the member approximately to its intended position. Another object is to provide a positioning gear in the form of an independently controllable unit for accurately positioning a load comprising an energy source, so that the positioning gear is able to work for a certain period without supply of energy from outside and which gear can be used at any location. Still another object of the invention is to provide a positioning gear only requiring energy for moving a load upwardly, the moving of the load downwardly being effected by only the load. This object is achieved by a positioning gear of the said type, whereby said gear comprises a controllable positioning element provided with a first attaching device for joining the element to a first cable section and a second attaching device for joining the element to a second cable section, following the first cable section, which can be joined to the load, said positioning element being able to vary the distance between said first and second attaching devices, said positioning element forming one movable assembly with an independent energy source or energy sources for operating the positioning element in a manner such that, after the positioning element has been joined to a cable, the entire assembly can be moved together with a load to be lifted or set down. Such a gear makes it possible for an assistant at installation level to be able to determine relatively rapidly and accurately the position of the load by controlling the positioning gear. This offers the great advantage that, in places where there is no room for placing trucks, cranes, and the like, which situation often occurs in towns with dense building and heavy traffic which must not be interrupted by closure, a load can nevertheless be set down in a simple and rapid manner at the desired position, which results in considerable savings in view of the costs of hiring a crane. An independent energy source offers the great advantage that it is possible to work without making use of the normal electricity supplies which are often not directly available at such sites, as a result of which the employment of special electricity cables, which can easily be damaged, would be compulsory. The same problems arise if it is necessary to employ a supply line for supplying gaseous or liquid pressure medium, such as compressed air. This construction also has the advantage that if the energy source is rechargeable, it can be kept small, and the recharging unit can be set down in the vicinity. Advantageously, the positioning element comprises a single acting controllable working pressure medium cylinder with which a load can be set down in a simple manner at a desired position. According to a very advantageous embodiment, the working pressure medium cylinder together with a supply source of working pressure medium in a supply source of incremental pressure medium with the associated connecting lines forms one assembly which can be suspended via the working pressure medium cylinder in a cable. In this case, the risk of the connecting lines being damaged is limited to a minimum. In this case, the operating means for the entire assembly is expediently constructed as mechanically operable operating means such as with a traction cord. The invention also relates to a method for placing a load at a desired position using a positioning gear according to the invention. Other claims and many of the attendant advantages will be more readily appreciated as the same becomes better understood by reference to the following detailed description and considered in connection with the accompanying drawings in which like reference symbols designate like parts without the figures. DESCRIPTION OF THE DRAWINGS FIG. 1 shows diagrammatically a hoisting crane with the positioning gear according to the invention; FIG. 2 shows diagrammatically an a large scale an embodiment of the positioning gear shown in FIG. 1; FIG. 3 shows diagrammatically a system in which several lifting and positioning gears according to the invention are used and, FIG. 4 shows diagrammatically another system in which several lifting and positioning gears are also incorporated. DESCRIPTION OF PREFERRED EMBODIMENT FIG. 1 shows a hoisting crane 28 having a crane jib 27 . Along the crane jib runs a travelling trolley 26 supporting a load 11 via a hoisting cable 10, a positioning gear 13 and cable sections 20 and 22. The force due to the weight of the load is compensated for by a counter-weight 29. The travelling trolley 26 and the hoisting cable 10 are operated by a crane driver 25 whose position is such that he can have a general overview of the positioning of the load. 24 shows a structure in which the load 11 is to be accurately positioned. The crane drive 25 brings the load 11 approximately to its intended position. Then an operator 39 operates the positioning gear 13 by means of control devices 30 in a manner such that the load 11 is brought precisely to its position in the structure 24. FIG. 2 shows diagrammatically a preferred embodiment of lifting and positioning gear according to the invention consists of a hydraulic cylinder. This cylinder comprises a piston 31 with a rod 18. The cylinder 1 has an opening 23 for the supply and discharge of hydraulic working pressure fluid in the space 14; because a simple-acting hydraulic cylinder 1 is involved in this case, the supply and discharge are combined in one line 32. Also arranged in line 32 is a security valve 35' which operates in two directions to prevent the flow velocity of the fluid working pressure medium from being too high. The line 32 leads to a pressure transformer 6, the pneumatic side of which is connected through a conduit 17, a valve 5 and a further conduit 16 to an energy supply source 8 of supplementary pressure medium, in the present embodiment a reservoir filled with gas under pressure, for example, a gas cylinder. The line 33 leads to a supply reservoir 3 for working pressure fluid in the present exemplary embodiment a hydraulic-pneumatic oil reservoir of a conventional type. Downstream of the energy supply source 8 for pressurized gas there is a reducing valve 9 which lowers the pressure of the gas from the supply source 8 to a usable level. Downstream of said reducing valve 9 there is a manually operable valve 5, controlled, for example, by a cord 37. The pressure transformer 6 of a conventional type converts the gas pressure from the source 8 into the pressure on the liquid working pressure medium with which the hydraulic cylinder 1 can be operated. The flow rate of the oil in the line 32 is determined by means of a rate regulating valve 7 which is preferably set beforehand. Although this may also be made controllable, it is preferable to set it beforehand in order to limit the number of operations performed by the operator in positioning the load to a minimum. Downstream of the oil reservoir or accumulator 3 in the line 33 there is a valve 2 which can be used to allow or interrupt the flow of oil in the line 33. Between the valve 2 and the hydraulic cylinder 1 there is a rate controlling valve 4 by means of which the flow rate of oil in the line 33 can be determined. Connected in parallel with valve 4 is a spring-loaded non-return valve 34 being oriented in such a manner that working pressure medium or oil can only flow through it in the direction of the hydraulic cylinder 1. Said nonreturn valve 34 is useful in order to be able to feed oil rapidly into the cylinder 1 (raising of unloaded piston 31 after the load 11 has been put down) since the flow rate would otherwise only be determined by valve 4. Preferably, the valve 4 is set beforehand for the same reasons as have been mentioned for valve 7. Valve 2 is expediently operated by a cord 36, in which case, to fix the operations for opening and closing the valves, said cord 36 may be connected to cord 37. A cable section 20 is attached via the device 19 to the housing of the cylinder 1, while a cable section 22 is attached to a device 21 mounted on the connecting rod 18 of piston 31. In the present embodiment, the cable section 20 is attached to the hoisting cable 10 of the crane 28 and the cable section 22 may be attached to the load 11. The cylinder 1, the pressure transformer 6, the accumulator 3 and the energy supply source 8 and associated lines, and also shut-off valves 2 and 5 are expediently mounted on a frame thus forming a unit so that by incorporating cylinder 1 in the hoisting cable 10 all the other parts are also suspended by means of that frame. As a result of this, the risk of damage to any member when the gear according to the invention is being used is virtually eliminated. The gear operates as follows. In the initial state, the valve 2 is open and the piston 31 is in its highest position under the influence of the hydraulic pressure from the accumulator 3. A load 11 is attached to the cable section 22 which is jointed to the piston rod 18. When the hoisting is started, the outward stroke of the piston 31 with connecting rod 18 will take place under the influence of the weight of the load 11. It should be noted that the space 38 above piston 31 is not connected with any pressure fluid. Thus the working pressure cylinder 1 is only single acting. During this first phase of the hoisting and the lowering of the piston 31, a flow of oil takes place from the cylinder 1 towards the oil reservoir 3; the flow rate (and consequently the speed of movement of the load) is set in advance or controlled by means of the rate regulating valve 4. The flow of the oil to the reservoir 3 is stopped by closing the valve 2. The load, which is not yet lifted in the initial stage, can now be raised by the crane 28 and brought near its intended position in the structure 24. Hereafter the intake stroke of the piston 31 with connecting rod 18 will take place under the influence of the pneumatic pressure from the gas reservoir 8. The valve 5 is opened, which produces a flow of gas under pressure to the pressure transformer 6 where the gas pressure is transmitted to the oil which will flow into the cylinder 1, as a result of which the piston 31 plus the load is moved upwards. This movement is stopped by closing the valve 5. After the load has been positioned at the desired place, and the load is no longer attached to the cable section 22, the intake stroke of the piston 31 with connecting rod 18 is effected by opening the valve 2 and consequently bringing about the connection between the oil reservoir 3 and the cylinder 1. Due to the pneumatic pressure in the reservoir 3, oil flows from oil reservoir 3 to the cylinder 1, as a result of which the unloaded piston 31 is forced upwards. Thereafter a new load may then be attached again to the cable section 22 and the lifting and positioning gear is again ready for use. The operating devices described above (the valves 2 and 5, the rate regulating valves 4 and 7) are connected in a known manner to control devices by means of which the operator is able to operate the lifting and positioning gear. Preference is given to mechanical operation of the valves 2 and 5, while the rate regulating valves are expediently set beforehand and are not regulated during the operation of the gear. FIG. 3 shows a use in which the load 11 has an appreciable surface area. The diagrammatically shown hoisting cable 10 divides up into two suspension cables 12 which divide up in turn into follow-on suspension cables 15. Lifting and positioning gear 13 according to the invention is located in one of the suspension cables 12 and in one of the follow-on suspension cables 15. This makes a more accurate positioning of the load 11 possible. Said lifting and positioning gears may each be connected separately to control devices 30, but they may also be connected to common control devices 30 so that one operator is able to operate the two lifting and positioning gears 13 together. It is clear that several lifting and positioning gears according to the invention may be connected both in series and in parallel. FIG. 4 finally shows yet another embodiment in which a hoisting cable 10 divides up into two follow-on cables 15a which support a supporting beam 38. In each of the follow-on cables 15a, positioning gear according to the invention is incorporated. In order to be able also to rotate the load 11, the supporting beam 38 is connected via a follow-on cable 15b and positioning gear 13 incorporated therein to an upper face 11' of the load 11. At the other end of the beam 38, another follow-on cable 15c is fitted which divides up into two cables 15d, 15e which are connected to side faces 11" and 11"'. Positioning gears 13 are also incorporated in the cables 15d and 15e.

Positioning device to be incorporated as a controllable coupling element between a load and the cable of a hoisting apparatus. The element includes a hydraulic cylinder connected to a hydro-pneumatic transformer and to a hydro-pneumatic reservoir. The transformer is connected to a source of pressurized gas through a first valve, a second valve being provided in the line from the cylinder to the reservoir. The cylinder, the transformer, the pressurized gas source, the reservoir and both valves are mounted in a common frame, both valves being operable from a distance.

RELATED APPLICATIONS The present application is a continuation-in-part of application PCT/EP2011052890, filed on 28 Feb. 2011, in Europe, and published as WO 2012116721 A1. BACKGROUND OF THE INVENTION 1. Field of the Invention This application relates to hearing aids. More specifically, it relates to a method for driving a digital output stage of a hearing aid. It also relates to a hearing aid configured for employing the method. In this context, a hearing aid is defined as a small, battery-powered device, comprising a microphone, an audio processor and an acoustic output transducer, configured to be worn in or behind the ear by a hearing-impaired person. By fitting the hearing aid according to a prescription calculated from a measurement of a hearing loss of the user, the hearing aid may amplify certain frequency bands in order to compensate the hearing loss in those frequency bands. In order to provide an accurate and flexible amplification, most modern hearing aids are of the digital variety. Contemporary digital hearing aids incorporate a digital signal processor for processing audio signals from the microphone into electrical signals suitable for driving the acoustic output transducer according to the prescription. In order to save space and improve efficiency, some digital hearing aid processors use a digital output signal to drive the acoustic output transducer directly without performing a digital-to-analog conversion of the output signal. If the digital signal is delivered to the acoustic output transducer directly as a digital bit stream with a sufficiently high frequency, the coil of the acoustic output transducer performs the duty as a low-pass filter, allowing only frequencies below e.g. 15-20 kHz to be reproduced by the acoustic output transducer. The digital output signal is preferably a pulse width modulated signal, a sigma-delta modulated signal, or a combination thereof. The most recent generations of hearing aids also incorporate a tiny radio receiver for the purpose of receiving radio signals intended for the hearing aid circuitry. Typical uses of such a radio receiver are remote controlling volume and program settings from a wireless remote control carried around by the hearing aid user, streaming of audio signals from an external source such as a television set, a compact disc player or a mobile telephone, wireless programming of the hearing aid by a hearing aid fitter according to a prescription, thus eliminating the need for cumbersome wires and fault-prone electrical contacts between the fitting equipment and the hearing aid, or synchronization signals from another hearing aid. The radio receivers employed for this purpose must be physically small, have modest power requirements, and perform reliably within the intended range of the transmitter used. An H-bridge is an electronic circuit for controlling inductive loads such as electric motors or loudspeakers. It operates by controlling the direction of a flow of current through a load connected between the output terminals of the H-bridge by opening and closing a set of electronic switches present in the H-bridge. The switches may preferably be embodied as semiconductor switching elements such as BJT transistors or MOSFET transistors. This operating principle permits a direct digital drive output stage to be employed in order to enable a suitably conditioned digital signal to drive a loudspeaker directly, thus eliminating the need for a dedicated digital-to-analog converter and at the same time reducing the power requirements for the output stage. A sigma-delta modulator is an electronic circuit for converting a signal into a bit stream. The signal to be converted may be digital or analog, and the sigma-delta modulator is typically used in applications where a signal of a high resolution is to be converted into a signal of a lower resolution. In this context, a sigma-delta modulator is used for driving the H-bridge output stage in the hearing aid. The diaphragm of a loudspeaker has a resting or neutral position assumed whenever no current flows through the loudspeaker coil and two extreme positions assumed whenever the maximal allowable current flows in either direction through the loudspeaker. By applying a sufficiently fast-changing bit stream from an H-bridge represented by positive and negative voltage impulses to the loudspeaker terminals, any position between the two extreme diaphragm positions of the loudspeaker may be attained. The higher the number of positive impulses in the bit stream is, the more the loudspeaker diaphragm will move towards the first extreme position, and the higher the number of negative impulses in the bit stream is, the more the loudspeaker diaphragm will move towards the second extreme position. Due to the low-pass filtering effect of the loudspeaker coil, no audible switching noise will emanate from the loudspeaker when driven in this way, provided the switching period of the bit stream is well above the reproduction frequency limit of the loudspeaker. Thus, a digital bit stream may control a loudspeaker directly. 2. The Prior Art Digital radio receivers, such as the kind disclosed in WO-A1-09/062500, are especially useful, as they require very little power while maintaining a comparatively high selectivity in the reception. Other types of radio receivers may be employed, but the limited power available in a hearing aid puts a severe restriction on the selectivity, and, as a consequence, the obtainable range and reliability of the radio receiver. A remote control transmitter for use with a hearing aid has a desirable range of approximately one meter while an internal transmitter in another hearing aid has a desirable range of roughly thirty centimeters. The remote control transmitter is capable of issuing various commands to the hearing aid such as program selection and volume control, and also of performing streaming of a digitally represented audio signal to the hearing aid, thus being highly dependent on the existence of a reliable transmission link from the transmitter to the receiver. A pair of hearing aids having a set of transmitters and receivers may have the capability to exchange central parameters relating to the signal processing in the hearing aids apart from program selections and volume settings. This capability is also dependent on the presence of a reliable transmission link between the two hearing aids. From EP-B1-1716723 is known a digital output stage for a hearing aid, said output stage comprising a sigma-delta converter and an H-bridge for driving an acoustic output transducer for a hearing aid. The output stage is denoted a three-level output stage because it is capable of delivering a bit stream consisting of three individual signal levels to the acoustic output transducer. In the following, these levels are denoted “+1”, “−1” and “0”, where “+1” equals the maximum positive voltage across the acoustic output transducer, “−1” equals the maximum negative voltage across the acoustic output transducer, and “0” equals no voltage. This utilizes the fact that a positive voltage pulse makes the diaphragm of the acoustic output transducer move in one direction, and a negative voltage pulse makes the diaphragm of the acoustic output transducer move in the other direction. By delivering a clocked bit stream consisting of “+1”-levels and “−1”-levels interspersed with “0”-levels as voltage pulses to the acoustic output transducer, any position deviation within the confinements of the mechanical suspension of the acoustic output transducer diaphragm may thus be obtained, as the loudspeaker coil acts as an integrator of the voltage pulses. The digital output stage of the prior art generates the “0”-level by applying a “+1”-level and a “−1”-level simultaneously to both terminals of the acoustic output transducer. This way of generating the “0”-level for the acoustic output transducer has the advantages of being very easy to implement, as no extra components are needed to provide the “0”-level, and to save power, as the “0”-level uses no extra current and the provision of three separate levels effectively doubles the possible voltage swing across the acoustic output transducer. However, it also has some inherent drawbacks, which will be explained in greater detail in the following. The “+1”-levels and “−1”-levels both generate differential voltages over the wires and terminals of the acoustic output transducer. This is not the case with the “0”-level. With the “0”-level, both wires carry the same voltage simultaneously, and since this is a voltage rapidly switching between the “+1”-level and “−1”-level it radiates more common mode signal energy to its immediate surroundings. This radiation results in increased crosstalk to nearby circuitry such as telecoils or wireless transmission receiver coils typically present in the hearing aid. Since this crosstalk has frequencies above 1 MHz, it does not possess a problem to a nearby telecoil, which may usually be found in a hearing aid, since a telecoil is configured to convey frequencies below 8-10 kHz. A wireless receiver coil, however, inevitably suffers a very considerable reduction in its signal-to-noise ratio from the capacitive interference signal induced by this crosstalk phenomenon, often to a degree where reliable signal reception becomes impossible. This capacitive interference emanates mainly from electrically exposed parts of the output circuit, primarily the wires connecting the output pads of the electronic circuit chip of the hearing aid to the input terminals of the acoustic output transducer. It is not possible to shorten these wires further for mechanical reasons, but some reduction in the capacitive coupling between these wires and sensitive electronic circuits in the vicinity may be achieved by twisting the wires and keeping them physically close together. The voltage pulses from the H-bridge output stage of the hearing aid are essentially presented to the output transducer as a square wave signal having a frequency of 1-2 MHz, and the resulting switching noise components from the “0”-levels generated in this manner may thus disturb the operation of electronic circuits sensitive to capacitive interference in this frequency range, such as a radio receiver. In cases where the afflicted electronic equipment incorporates a wireless remote control receiver in the hearing aid the problems caused by electromagnetic interference are exceptionally severe, as the effective operating range of the wireless remote control is limited considerably by the capacitive interference emanating from the output stage, excluding the remote control signals from proper reception. WO-A1-03/047309 discloses a digital output driver circuit for driving a loudspeaker for a mobile device such as a hearing aid or a mobile phone. The digital driver circuit comprises an input, a modulator and a three-level H-bridge and is integrated into the loudspeaker enclosure in order to shield the driver circuit from electromagnetic interference and to keep the wires connecting the driver output to the loudspeaker short. The driver circuit further comprises a feedback circuit connected to the loudspeaker for regulating the supply voltage for the driver circuit. An output driver integrated into a loudspeaker, such as described by the teachings of WO-A1-03/047309, is not interchangeable with dynamic standard loudspeakers of the kind used in hearing aids. If, for example, a hearing aid housing and circuitry may be adapted for use with a range of different loudspeakers having different impedance values, e.g. for treating different degrees of hearing loss, a loudspeaker having an integrated output driver would not be well suited for this configuration. Hearing aids configured for being used with receiver-in-the-ear (RITE) loudspeakers would also be impractical to implement using this method. In cases where this type of flexibility is desired, long wires between the output stage terminals of the hearing aid circuit and the terminals of the loudspeaker of the hearing aid are unavoidable. An extra set of long wires for the signal from the loudspeaker to the feedback circuit would also be required by the prior art output driver, which would further increase the capacitive interference noise. The invention, in a second aspect, provides a method of driving an output stage for a hearing aid, said hearing aid having at least one input transducer, an analog-to-digital converter, a digital signal processor, a sigma-delta modulator, a first quantizing block, a second quantizing block, a decoder, an H-bridge output converter, an acoustic output transducer, a timer, a controller and a radio receiver, the radio receiver having an idle mode of operation and a listening mode of operation, said method comprising the steps of generating a driving signal in the sigma-delta modulator based on an output signal from the digital signal processor, processing, in the first quantizing block, using the sigma-delta modulator output signal to generate a first bit stream adapted for defining two discrete levels, processing, in the second quantizing block, using the sigma-delta modulator output signal to generate a second bit stream adapted for defining three discrete levels, the controller using the timer to execute a control sequence for enabling the decoder to select one bit stream among the first and the second bit streams and control the operating mode of the radio receiver, the decoder selecting the first bit stream whenever the radio receiver is in the listening mode, the decoder selecting the second bit stream whenever the radio receiver is in the idle mode, and providing a drive signal for the H-bridge output converter based on the selected bit stream. This method of driving an output stage of the H-bridge variety for a hearing aid achieves that the power efficiency of an output stage operating with three levels is maintained as closely as possible while minimizing the problems caused by the interference also associated with a three-level output stage. By taking the operating mode of the radio receiver into account when selecting the operating mode of the sigma-delta modulator, the H-bridge output converter is driven in a three-level mode whenever the radio receiver is in the idle mode, i.e. when it is not receiving any signals. In this case, power consumption is reduced by driving the H-bridge output converter in a three-level mode. Whenever the radio receiver is in the listening mode, the H-bridge output converter is driven in a two-level mode. In this case, the power consumption is increased somewhat, but the interference associated with driving the H-bridge output converter in the three-level mode is reduced. In a preferred embodiment, the controller enables the radio receiver to enter the listening mode periodically, e.g. twenty times per second, in turn causing the H-bridge output converter to operate in the two-level mode for the duration the radio receiver is in the listening mode. The duration of the listening mode period may be relatively short, e.g. ten milliseconds, unless the radio receiver detects a radio signal within the listening mode period. Otherwise, the radio receiver may reenter the idle mode, in turn causing the H-bridge output converter to operate in the three-level mode again. However, if the radio receiver detects the presence of a radio signal within the listening mode period, reentrance by the radio receiver to the idle mode is suppressed until no radio signal has been detected for the duration of a predetermined period, e.g. a tenth of a second. Then the radio receiver reenters the idle mode, thus forcing the H-bridge output converter to operate in the three-level mode again. The invention, in a second aspect, provides a hearing aid having at least one input transducer, an analog-to-digital converter, a digital signal processor, a sigma-delta modulator, a first quantizing block, a second quantizing block, a decoder, an H-bridge output converter, an acoustic output transducer, a timer, a controller and a radio receiver, the radio receiver having an idle mode of operation and a listening mode of operation, the sigma-delta modulator being adapted for generating a driving signal based on an output signal from the digital signal processor, the first quantizing block being adapted for generating a first bit stream and the second quantizing block being adapted for generating a second bit stream based on the sigma-delta modulator output signal, the first bit stream incorporating two discrete levels and the second bit stream incorporating three discrete levels, the controller being adapted for enabling the decoder to select one bit stream among the first and the second bit streams and for controlling the operating mode of the radio receiver, wherein said controller is configured to make the decoder select the first bit stream whenever the radio receiver is in the listening mode, and make the decoder select the second bit stream whenever the radio receiver is in the idle mode. Additional features will appear from the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be explained in greater detail with respect to the drawings, where FIG. 1 is a schematic of an H-bridge output stage for a hearing aid according to an embodiment of the invention, FIG. 2 is a table showing possible states of the H-bridge output stage of the hearing aid according to an embodiment of the invention, FIG. 3 is a flowchart of an algorithm for controlling the operating modes according to an embodiment of the invention, FIG. 4 is a graph illustrating the operating sequence of the output stage and the radio receiver of the hearing aid according to an embodiment of the invention, and FIG. 5 is a schematic of a hearing aid having an H-bridge output stage according to an embodiment of the invention. DETAILED DESCRIPTION The schematic in FIG. 1 shows an output stage 1 for use with a hearing aid according to the invention. The output stage comprises a sigma-delta modulator 2 , a first comparator 8 constituting a first quantizer, a second quantizer 13 comprising a second comparator 9 and a third comparator 10 , a decoder 11 , an H-bridge 12 , a controller 16 , a control wire 14 , a controlled switch 15 , a radio receiver 17 , an antenna 18 and an acoustic output transducer 19 . The sigma-delta modulator 2 comprises a difference node 3 , a first summing node 4 , a second summing node 5 , a first unit delay block 6 and a second unit delay block 7 . The H-bridge comprises a first transistor 20 , a second transistor 21 , a third transistor 22 , and a fourth transistor 23 . Also shown in FIG. 1 is an output terminal from a digital signal processor DSP of the hearing aid. The output terminal of the digital signal processor DSP is connected to the input of the sigma-delta converter 2 . The output terminal of the digital signal processor DSP is connected to a first input of the difference node 3 of the sigma-delta converter 2 , and a feedback loop from the output of the sigma-delta converter 2 is connected to a second input of the difference node 3 . The output of the difference node 3 is connected to a first input of the first summing node 4 , and the output of the first unit delay block 6 is connected to a second input of the first summing node 4 . The output of the first summing node 4 is split between an input of the first unit delay block 6 and a first input of the second summing node 5 . An output of the second unit delay block 7 is connected to a second input of the second summing node 5 , and the output of the second summing node 5 is split between an input of the second unit delay block 7 , the feedback loop feeding the difference node 3 , and the positive inputs of the first comparator 8 , the second comparator 9 and the third comparator 10 , respectively. The output of the sigma-delta modulator 2 is connected to the positive input terminals of the first comparator 8 , the second comparator 9 , and the third comparator 10 , respectively. The negative input terminal of the first comparator 8 is connected to logical LOW, the negative input terminal of the second comparator 9 is connected to the logical level X, and the negative input terminal of the third comparator 10 is connected to the logical level Y. The output of the first quantizer 8 is connected to a first input of the decoder 11 , and the outputs of the second quantizer 13 are connected to a second and a third input of the decoder 11 . Based on the output signal from the sigma-delta modulator 2 , the first quantizer 8 is capable of generating two different quantization levels and the second quantizer 13 is capable of generating three different quantization levels. A first output of the decoder 11 is connected to the first transistor 20 of the H-bridge 12 , a second output of the decoder 11 is connected to the second transistor 21 of the H-bridge 12 , a third output of the decoder 11 is connected to the third transistor 22 of the H-bridge 12 , and a fourth output of the decoder 11 is connected to the fourth transistor 23 of the H-bridge 12 . The source terminals of the first transistor 20 and the third transistor 22 are connected to V ss . The drain terminal of the first transistor 20 and the source terminal of the second transistor 21 are connected to a first terminal of the acoustic output transducer 19 . The drain terminal of the third transistor 22 and the source terminal of the fourth transistor 23 are connected to a second terminal of the acoustic output transducer 19 , and the drain terminals of the second transistor 21 and the fourth transistor 23 are connected to V dd . The control wire 14 of the controller 16 is connected to the control input of the controlled switch 15 and to a control input of the decoder 11 , respectively. The controlled switch 15 connects an output of the radio receiver 17 to an input of the controller 16 , disabling this connection whenever the controlled switch 15 is open. A signaling wire connects the radio receiver 17 to the controller 16 for providing data based on radio signals picked up by the antenna 18 and demodulated by the radio receiver 17 to the controller 16 . When in use, the digital signal processor DSP provides a bit stream representing an audio signal to the input of the sigma-delta modulator 2 . The bit stream is conditioned by the sigma-delta modulator 2 in order to suit the inputs of the first comparator 8 , the second comparator 9 and the third comparator 10 , respectively. The first comparator 8 acts as a first two-level quantizer on the output signal from the sigma-delta modulator 2 , and the second comparator 9 and the third comparator 10 in combination act as a second three-level quantizer 13 on the output signal from the sigma-delta modulator 2 . The first comparator 8 outputs a logical LOW level whenever the level of the output signal from the sigma-delta modulator 2 is below a first, predetermined limit and a logical HIGH level whenever the signal is above said first, predetermined limit. The second comparator 9 outputs a logical LOW level whenever the input signal is below the limit X and a logical HIGH level whenever the input signal is above the limit X. The third comparator 10 outputs a logical LOW level whenever the input signal is below the limit Y and a logical HIGH level whenever the input signal is above the limit Y. Together, the second comparator 9 and the third comparator 10 may thus generate four possible levels for the decoder 11 . However, only three of these levels are utilized in the decoder 11 , as the condition where the output of the second comparator 9 is logical HIGH and the output of the third comparator 10 is logical LOW is treated equally to the condition where the output of the second comparator 9 is logical LOW and the output of the third comparator 10 is logical HIGH. The three conditions may be interpreted by the decoder 11 as e.g. the symbol “−1” for input levels resulting in both comparator outputs being logical LOW, the symbol “0” for input levels resulting in the two comparator outputs being mutually different, i.e. one comparator output is logical LOW while the other comparator output is logical HIGH, and the symbol “+1” for input levels resulting in both comparator outputs being logical HIGH. In this way, the first quantizer 8 effectively generates two discrete levels from the input signal from the sigma-delta modulator 2 , and the second quantizer 13 effectively generates three discrete levels from the input signal from the sigma-delta modulator 2 . The decoder 11 is capable of selecting either the two-level output from the first quantizer 8 or the three-level output from the second quantizer 13 as the input signal to be decoded. The decoder 11 , together with the H-bridge 12 , is capable of driving the loudspeaker 19 in a two-level mode of operation whenever the output signal from the first quantizer 8 is selected as the input signal, and in a three-level mode of operation whenever the output signal from the second quantizer 13 is selected as the input signal. The decision about which output to use as an input of the decoder 11 is determined by the state of the control wire 14 of the controller 16 . The control wire 14 may be in an asserted state or in an unasserted state, respectively. Whenever the control wire 14 is in the asserted state, the decoder 11 uses the output signal from the two-level output of the first quantizer 8 as its input signal. Asserting the control wire 14 also closes the switch 15 , thereby enabling the radio receiver 17 to receive radio signals via the antenna 18 . Whenever the radio receiver 17 is enabled to receive radio signals, information about the presence of a radio signal is conveyed to the controller 16 through a separate wire (not shown). Whenever the control wire 14 is in the unasserted state, the decoder 11 uses the output signal from the three-level output of the second quantizer 13 as its input signal. Unasserting the control wire 14 also opens the switch 15 , thereby disabling the radio receiver 17 from receiving radio signals. Whenever the decoder 11 receives a “−1”-symbol for decoding, it turns on the second transistor 21 and the third transistor 22 , respectively, of the H-bridge 12 . The second transistor 21 connects the upper terminal of the acoustic output transducer 19 to the positive voltage V dd , and the third transistor 22 connects the lower terminal of the acoustic output transducer to the negative voltage V ss , and the loudspeaker membrane moves inwards. Whenever the decoder 11 receives a “+1”-symbol for decoding, it turns on the first transistor 20 and the fourth transistor 23 , respectively, of the H-bridge 12 . The first transistor 20 connects the upper terminal of the acoustic output transducer 19 to the negative voltage V ss , and the fourth transistor 23 connects the lower terminal of the acoustic output transducer to the positive voltage V dd , and the loudspeaker membrane moves outwards. Whenever the decoder 11 receives a “0”-symbol for decoding, it turns on the second transistor 21 and the fourth transistor 23 , respectively, of the H-bridge 12 . Both the second transistor 21 and the third transistor 22 then connect the upper terminal and the lower terminal of the acoustic output transducer 19 to the negative voltage V ss , and the loudspeaker membrane moves towards its resting position. The controller 16 coordinates the quantization resolution of the output signal from the sigma-delta modulator 2 with the operation of the radio receiver 17 in such a way that the radio receiver 17 is disabled whenever the decoder 11 is using the three-level input for controlling the H-bridge 12 , and in such a way that the radio receiver 17 is enabled whenever the decoder 11 is using the two-level input for controlling the H-bridge 12 . The table shown in FIG. 2 illustrates the possible states of the connecting wires of an acoustic output transducer similar to the acoustic output transducer 19 in FIG. 1 when connected to the H-bridge output stage of the hearing aid according to an embodiment of the invention. Beside the table is sketched an acoustic output transducer having connecting terminals A and B. In the configuration of a preferred embodiment of the hearing aid according to the invention, a sigma-delta converter together with a first quantizer, a second quantizer and a decoder may generate either two or three different output symbols intended for the H-bridge output stage of the hearing aid. When the symbol “−1” is generated, the H-bridge output stage connects the terminal A of the acoustic output transducer to a negative voltage, preferably the negative battery voltage, denoted V dd , and the terminal B of the acoustic output transducer to a positive voltage, preferably the positive battery voltage, denoted V ss . This induces an electromotive force in the transducer coil of the acoustic output transducer in the direction from terminal B to terminal A, and a transducer membrane mechanically connected to the transducer coil will thus move in one direction, say, inwards. When the symbol “+1” is generated, the H-bridge output stage connects the terminal A of the acoustic output transducer to the positive battery voltage V ss , and the terminal B of the acoustic output transducer to the negative battery voltage V dd . This induces an electromotive force in the transducer coil of the acoustic output transducer in the opposite direction, i.e. from terminal A to terminal B, and the transducer membrane will thus move in the opposite direction, say, outwards. When the symbol “0” is generated, the H-bridge output stage connects both the terminal A and the terminal B of the acoustic output transducer to the negative battery voltage V dd . No electromotive force is induced in the transducer coil of the acoustic output transducer in this case, and the transducer membrane will thus move towards its resting position. When the H-bridge is put into two-level mode, the symbol “0” is not generated. The switching between two-level mode and three-level mode is beneficially performed in the decoder. By changing the quantization resolution of the output signal from the sigma-delta modulator from two levels to three levels, or vice versa, in the decoder, the feedback history of the sigma-delta modulator is preserved in its entirety. As shown in FIG. 1 , this may be performed by the decoder having both the two-level and the three-level quantization resolution available at all times, and selecting the appropriate quantization resolution for driving the output for the acoustic output transducer of the hearing aid as necessary. The fact that the feedback history of the sigma-delta modulator is preserved in its entirety implies that switching between the two-level mode and the three-level mode of the sigma-delta modulator is performed seamlessly with regard to the output signal to the acoustic output transducer without any audible artifacts. An easy way of providing both a two-level modulation and a three-level modulation of the bit stream could be to employ two separate sigma-delta modulators. If a two-level sigma-delta modulator in parallel with a three-level sigma-delta modulator were used instead of a single sigma-delta modulator having both two-level and three-level capability, the feedback history of the sigma-delta modulator would be lost every time a transition from the two-level mode to the three-level mode, or vice versa, were made. This configuration would inevitably introduce undesirable, spurious transients into the output signal. By introducing a single sigma-delta modulator capable of selectively producing both a two-level and a three-level modulation of the output bit stream, the feedback history of the output stage is preserved when switching between different quantizing resolutions. In FIG. 3 is shown a flowchart illustrating a preferred control algorithm for a radio receiver and an H-bridge output stage of the hearing aid according to the invention. The timing values used by the algorithm in FIG. 3 are calculated and detected by an external subroutine, and are thus not shown. Only the timing flags are passed implicitly to the algorithm shown in FIG. 3 based on the timing values encountered by the system. The algorithm, initiating in step 301 , continues immediately to step 302 , where the radio receiver is put into an idle mode. The algorithm sets the H-bridge output stage in a three-level mode in step 303 and enters a loop in step 304 . In step 304 , the algorithm determines if fifty milliseconds have elapsed since the radio receiver was last put into the idle mode. If this is not the case, the algorithm loops back into step 304 until the fifty milliseconds have elapsed, and continues to step 305 , where the radio receiver is put into a listening mode. The algorithm then continues unconditionally to step 306 , where the H-bridge output stage is put into a two-level mode. The algorithm continues in step 307 , where an indicator in the radio receiver informs the algorithm if a radio signal is present. If this is not the case, the algorithm branches out into a test, carried out in step 308 , to determine if ten milliseconds have elapsed since the radio receiver were put into the listening mode without detecting a signal. If ten milliseconds have not yet elapsed, the algorithm loops back into step 307 in order to test if a radio signal has been picked up yet by the radio receiver. Otherwise, if ten milliseconds have elapsed without the radio receiver detecting the presence of a radio signal, the algorithm loops back into step 302 , where the radio receiver is put back into the idle mode, and continues unconditionally into step 303 , where the H-bridge is put back into the three-level mode and the procedure of the algorithm is repeated indefinitely. If, however, a radio signal is indeed detected by the radio receiver while the algorithm is processing step 307 , the algorithm instead continues into step 309 , where a subroutine (not shown) is called for carrying out the process of decoding the data bits received by the radio receiver of the hearing aid. The algorithm continues into step 310 , where a test is carried out in order to determine if one hundred milliseconds have elapsed since a signal was detected by the radio receiver. If this is not the case, the algorithm loops back into step 309 and continues the process of decoding the data bits received by the radio receiver. Otherwise, the algorithm continues into step 311 , where a test is carried out in order to determine if a radio signal is still present. If this is the case, the algorithm loops back into step 309 and continues the decoding process. If this is not the case, the algorithm instead loops back into step 302 , where the radio receiver is put back into the idle mode, and continues to step 303 , where the H-bridge is put back into the three-level mode. The essence of the functionality of the algorithm shown in FIG. 3 is as follows: The radio receiver of the hearing aid is put into the idle mode and the H-bridge output stage of the hearing aid is put into the three-level mode for fifty milliseconds. Then the radio receiver listens for the presence of a radio signal while the H-bridge output stage is put into the two-level mode in order to minimize interference. If no signal has been detected by the radio receiver for a period of ten milliseconds, the radio receiver is put back into the idle mode and the H-bridge output stage is put back into the three-level mode in order to conserve power. However, if the radio receiver of the hearing aid detects the presence of a radio signal, reception and decoding of the received radio signal is commenced. Every 0.1 seconds a test is performed in order to determine if a radio signal is still present. If this is the case, the reception and decoding of the received radio signal continues. If a radio signal is no longer deemed to be present, the radio receiver is once again put back into the idle mode and the H-bridge output stage is put back into the three-level mode in order to conserve power. FIG. 4 shows an exemplified set of graphs illustrating the interoperational characteristics between an output stage and a radio receiver in a hearing aid according to the invention. The upper graph in FIG. 4 illustrates the state of the control wire 14 of the controller 16 as shown in FIG. 1 , the middle graph in FIG. 4 shows the output signal of the H-bridge 12 seen across the input terminals of the acoustic output transducer 19 in FIG. 1 , and the lower graph in FIG. 4 shows the activity of the receiver 17 in FIG. 1 when controlled by the controllable switch 15 controlled by the control wire 14 of the controller 16 in FIG. 1 . All three graphs are assumed to be synchronous. The upper graph in FIG. 4 illustrates that the control wire 14 of FIG. 1 is asserted for short periods of time, thus enabling the radio receiver 17 in FIG. 1 and forcing the H-bridge output stage to operate in the two-level mode. Whenever the control wire is unasserted, the radio receiver is disabled and the H-bridge output stage is operated in the three-level mode. This is illustrated by the middle graph in FIG. 4 , where an arbitrary output signal from the H-bridge output stage is exhibiting three-level operation when the control wire is unasserted and two-level operation when the control wire is asserted. The lower graph in FIG. 4 illustrates the operation of the receiver 17 in FIG. 1 . The operation of the output stage of the hearing aid according to the invention, as illustrated by the graphs in FIG. 4 , will now be explained in further detail with reference to the elements shown in FIG. 1 . Below the lower graph in FIG. 4 is suggested a timeline with eight time instants, labeled from T 1 to T 8 . At the instant 0, the control wire 14 is unasserted, the radio receiver 17 is inactive, and the H-bridge output stage 1 is operating in the three-level output mode, delivering the three-level digital output signal directly to the acoustic output transducer 19 of FIG. 1 . At the instant T 1 , the control wire 14 is asserted, and the H-bridge output stage 1 changes its operation from the three-level output mode to the two-level output mode. At the same time, the radio receiver 17 is activated. This condition persists until the instant T 2 , approximately ten milliseconds later, where the control wire 14 is unasserted, the radio receiver 17 is inactivated, and the H-bridge output stage 1 is set to change its operation back into the three-level output mode. From the instant T 2 until the instant T 3 , approximately fifty milliseconds later, the control wire 14 is unasserted, leaving the H-bridge in the three-level output mode and the radio receiver 17 inactive. In this case, a radio signal R 0 , superimposed onto the lower graph of FIG. 4 in a dotted line, incidentally occurs between the instant T 2 and the instant T 3 . Because the radio receiver 17 is in its inactive mode, the radio signal R o is not picked up by the radio receiver 17 of the hearing aid. At the instant T 3 , the radio receiver 17 is activated again by asserting the control wire 14 , and the H-bridge output stage 1 changes its operation from the three-level output mode to the two-level output mode. Since no radio signal is detected by the radio receiver 17 between the instant T 3 and the instant T 4 , the control wire 14 is unasserted at the instant T 4 , approximately ten milliseconds later, when the radio receiver 17 is deactivated again, and the H-bridge output stage 1 has its operation changed back into the three-level output mode. Between the instant T 4 and the instant T 5 , another radio signal R 1 , superimposed onto the lower graph of FIG. 4 in a thin, solid line, occurs, but since it is still present at T 5 , it is detected by the radio receiver 17 . The detection of the radio signal R 1 by the radio receiver 17 makes the controller 16 keep the control wire 14 asserted, thus keeping the radio receiver 17 active and the H-bridge output stage 1 operating the two-level output mode. Within the time period between the instant T 5 and the instant T 6 , a third radio signal R 2 , superimposed onto the lower graph of FIG. 4 in a thin, solid line, is detected and decoded by the radio receiver 17 . The radio receiver 17 keeps a reception flag asserted during reception of the radio signal R 2 , and thus prevents the return of the radio receiver 17 to its inactive state. This, in turn, also delays the return of the H-bridge output stage 1 to the two-level output mode. When the radio signal R 2 ceases, a timing function delays the unassertion of the control wire 14 for a predetermined period of time. As no other radio signal is detected before the instant T 6 , the control wire 14 is unasserted again at T 6 . Hereby the radio receiver 17 is inactivated, and the H-bridge output stage 1 changes its operation back to the three-level output mode. At the instant T 7 , after approximately another fifty milliseconds, the radio receiver 17 is activated again by asserting the control wire 14 , and the H-bridge output stage 1 changes its operation from the three-level output mode to the two-level output mode. The control wire 14 is unasserted again at the instant T 8 , approximately ten milliseconds later, whereby the radio receiver 17 is deactivated again, and the H-bridge output stage 1 changes its operation back into the three-level output mode. In order to demonstrate the operating principles of the H-bridge output stage according to an embodiment of the invention, the three bursts of radio transmission illustrated by the lower graph in FIG. 4 are shown as being rather short. This is done to illustrate, in as brief a way as possible, the fact that the radio receiver 17 is only capable of receiving radio signals when it is activated by the controller 16 of the hearing aid, and that the radio receiver 17 has the ability to delay a pending inactivation whenever a radio signal is encountered. In a practical example, radio transmissions intended for the hearing aid will be significantly longer, preferably spanning a considerably longer period of time than the sixty milliseconds shown elapsing between two activations of the radio receiver in the example. In FIG. 5 is shown a schematic of a hearing aid 40 incorporating an H-bridge output stage according to an embodiment of the invention. The hearing aid 40 comprises an acoustic input transducer 30 , an analog-to-digital converter 31 , a digital signal processor 32 , a sigma-delta modulator 2 , a first quantizer block 8 , a second quantizer block 13 , a decoder 11 , an H-bridge 12 , a controller 16 , a control wire 14 , a controllable switch 15 , a timer 33 , an acoustic output transducer 19 , and a radio receiver 17 having an antenna 18 . In FIG. 5 is also shown a radio transmitter 34 having an antenna 35 . The sigma-delta converter 2 , the decoder 11 , the controller 16 , the H-bridge 12 , the acoustic output transducer 19 and the radio receiver 17 are considered to be similar to the corresponding parts of the system shown in FIG. 1 . When in use, the microphone 30 of the hearing aid 40 picks up acoustic signals and converts them into electrical signals and feeds the electrical signals to an input of the analog-to-digital converter 31 . The digital output signal from the analog-to-digital converter 31 is used as the input for the digital signal processor 32 , where the main part of the signal processing, e.g. filtering, compression, prescription gain calculation etc. takes place. The output signal from the digital signal processor 32 is a digital signal, which is fed to the input of the sigma-delta modulator 2 . The output signal from the sigma-delta modulator 2 , which may be considered to be a digital bit stream, is split into two branches, one branch going to the first quantizing block 8 , and the second branch going to the second quantizing block 13 . The output signals from the first and second quantization blocks 8 , 13 , are presented as input signals to the decoder 11 . The decoder 11 generates a set of control signals for the H-bridge 12 . The output terminals of the H-bridge 12 are connected to the input terminals of the acoustic output transducer 19 , and the H-bridge 12 generates a digital output signal for the acoustic output transducer 19 . The output signal from the first quantization block 8 is a two-level bit stream intended for driving the H-bridge 12 in a two-level mode via the decoder 11 . The output signal from the second quantization block 13 is a three-level bit stream intended for driving the H-bridge 12 in a three-level mode via the decoder 11 . The decoder 11 is thus capable of selecting either the output signal from the first quantization block 8 or the output signal from the second quantization block 13 as the input signal for generating the set of control signals for the H-bridge 12 . When the two-level output signal from the first quantization block 8 is used, the decoder 11 is said to be operating in a two-level mode, and when the three-level output signal from the second quantization block 13 is used, the decoder 11 is said to be operating in a three-level mode. The radio receiver 17 is capable of operating in an idle mode, wherein radio signal reception is suppressed, and in an active mode, wherein radio signal reception is enabled. The controller 16 determines which mode the decoder 11 is supposed to be using in a given situation in order to generate the set of control signals for the H-bridge 12 . For this purpose, the controller 16 utilizes information from the timer 33 and the radio receiver 17 , respectively, to determine what the mode of operation for the decoder 11 should be. The timer 33 generates a timing sequence similar to the timing sequence shown in FIG. 4 . This timing sequence is used by the controller 16 to control the operation of the decoder 11 and the radio receiver 17 of the hearing aid 40 . During a first phase of the timing sequence, the timer 33 sends a signal to the controller 16 at regular intervals in order to make it change the operation of the radio receiver 17 from the idle mode to the active mode and force the decoder 11 to select the two-level bit stream from the first quantizer block 8 for the H-bridge 12 in order for it to operate in the two-level mode. When the controller 16 determines that the radio receiver 17 should change its mode of operation from the idle mode to the active mode based on the signal from the timer 33 , the controller 16 asserts the control wire 14 in order to engage the controlled switch 15 for activating the radio receiver 17 . Simultaneously, the controller 16 forces the decoder 11 , via the control wire 14 , to select the two-level bit stream originating from the first quantizing block 8 for controlling the H-bridge 12 . The radio receiver 17 is now in the active mode, and the H-bridge 12 is producing a two-level bit stream for the acoustic output transducer 19 . Unless the radio transmitter 34 transmits a radio signal which is picked up by the radio receiver 17 while it is in the active mode, the controller 16 waits for a signal from the timer 33 and unasserts the control wire 14 upon detecting the signal from the timer 33 , thus disengaging the controlled switch 15 , in turn forcing the radio receiver 17 back into the idle mode, and makes the decoder 11 select the three-level bit stream from the second quantizing block 13 for controlling the H-bridge 12 . If, however, the radio transmitter 34 transmits a radio signal, and this radio signal is detected by the radio receiver 17 , a signal is sent from the radio receiver 17 to the controller 16 , informing the controller 16 to postpone signals from the timer 33 until the radio receiver 17 informs the controller 16 that it has finished receiving and decoding the radio signal. The timer 33 now enters a second phase in the timing sequence, wherein the controller 16 regularly checks the status of the radio receiver 17 in order to determine that the radio receiver 17 is still receiving and decoding a radio signal. If this is the case, the controller maintains status quo, i.e. it keeps the H-bridge 12 operating in the two-level mode and keeps the radio receiver 17 in the active mode. When the radio transmitter 34 ends a transmission, the radio receiver 17 stops detecting a radio signal, and thus ends the decoding process. Upon terminating the decoding process, the radio receiver 17 sends a signal to the controller 16 in order to convey the information that reception of the radio signal has ended. Upon getting this piece of information, the controller 16 then waits for a signal from the timer 33 before deactivating the radio receiver 17 and forcing the H-bridge 12 into the three-level mode, producing a three-level bit stream to the acoustic output transducer 19 . In a preferred embodiment, the first phase of the timing sequence of the timer 33 , as described in the foregoing, is considerably shorter than the second phase. This relationship between the two phases of the timing sequence is preferred because it allows the H-bridge 12 to operate for as long as possible in the power-saving three-level mode of operation during the first phase of the timing sequence, and prevents premature reentrance of the H-bridge 12 into the three-level mode of operation while the radio receiver 17 receives and decodes a radio signal, thus reducing the risk of the reception of the radio signal being corrupted by capacitive interference from the H-bridge 12 .

In a hearing aid ( 40 ), a direct-digital H-bridge output driver stage ( 1 ) driven by a sigma-delta modulator ( 2 ) is configured to operate in a power-saving three-level output mode or a power-consuming two-level output mode. The three-level output mode of the H-bridge output driver stage ( 1 ) has low power consumption but suffers the disadvantage of emitting capacitive noise potentially interfering with the reception of radio signals in a radio receiver ( 17 ) in the hearing aid ( 40 ). By providing a novel method of selecting the two-level output mode whenever the radio receiver ( 17 ) is receiving signals, and selecting the three-level output mode whenever the radio receiver ( 17 ) is idle, this capacitive interference does not disturb the radio receiver ( 17 ) in the hearing aid ( 40 ). The invention provides a method and a hearing aid.

CROSS-REFERENCED RELATED APPLICATIONS [0001] This application is a continuation of International Patent Application No. PCT/CH2009/000042 filed Feb. 4, 2009, which claims priority to Swiss Patent Application No. 189/08 filed Feb. 11, 2008, the entire contents of each are incorporated herein by reference. BACKGROUND [0002] The present invention relates to devices for administering, injecting, infusing, delivering or dispensing a substance, and to methods of making and using such devices. More particularly, it relates to a device for administering a fluid or liquid product or substance, e.g. fluid medicaments, pharmaceuticals or cosmetics. More particularly, it relates to a device for administering a fluid product that is to be mixed in a two-chamber carpule (which also may be thought of and/or referred to as an ampoule, container, or the like) before use. [0003] In the treatment of various diseases, e.g. diabetes, and in cases of impaired growth, injection devices or appliances, which may be called injections pens or simply pens, are used to inject a medicament in the form of a fluid product into the body tissue. Such pens can also be used for other pharmaceutical or cosmetic purposes. Typically, a pen comprises a housing, an administering mechanism accommodated at least partially in the housing, and a receptacle for receiving the fluid product, e.g. a carpule holder, which receives a carpule and which is supported by or attached to the housing to connect the carpule to the administering mechanism. Generally, the administering mechanism is composed of a mechanism that is able to drive or move a stopper in the carpule. Generally, at the end of the carpule holder and directed away from the mechanism, an injection needle unit is fitted which forms a fluid connection to the fluid product in the carpule. Typically, an injection pen comprises a trigger button, the actuation of which activates the administering mechanism, such that the medicament is ejected from the carpule through the injection needle. In the prior art, it is known to block or lock the trigger button or to cover it, or in some other way to safeguard against accidental triggering. The blocking or safety feature is overridden or released just before use of the injection pen to be able to carry out an injection. [0004] Two-chamber carpules are often used in practice, these being provided, for example, for administration of hormone preparations. The two-chamber carpules have a first chamber with a lyophilized active substance, and a second chamber with a solvent. The active substance is dissolved in the solvent just before administration, by the solvent being conveyed into the chamber containing the active substance. These two-chamber carpules have two stoppers, which separate the two chambers from each other. During the mixing of the active substance, the two stoppers are moved inside the carpule in such a way that the solvent can run through a bypass into the chamber containing the active substance. Especially when using two-chamber carpules of this kind in an injection pen, it is important to ensure that no accidental or premature administration is initiated, since in such cases the medicament may not have been completely mixed. SUMMARY [0005] It is an object of the present invention to make available an administering device which minimizes or avoids the chance of accidental or premature actuation of the device and thus increases the safety of the device. [0006] In one embodiment, the present invention comprises an apparatus for administering a substance, comprising a housing, an administering mechanism accommodated in the housing, an actuation element for actuating the administering mechanism, a receptacle for holding the substance, and a lock for releasably locking the actuation element, wherein the receptacle is rotatable relative to the housing and the lock can be unlocked by rotating the receptacle. [0007] In one embodiment, the present invention comprises a device for administering a fluid product comprising a housing for receiving an administering mechanism, an actuation element for actuating the administering mechanism, a receptacle for receiving the fluid product, and a blocking mechanism (which also may be thought of and/or referred to as a lock) for blocking the actuation element. The housing of the device can have a sleeve-shaped configuration, such that the device has the shape of a pen or pencil. An aspect of the configuration of the housing is that the administering mechanism can be accommodated therein without its function being impaired. It is also possible for the housing to carry and/or include functional elements of the administering mechanism and, thus, form part of the administering mechanism. [0008] In some embodiments, for example, the administering mechanism is composed of a mechanism generally comprising an advancing member, e.g. a piston rod, which can be advanced relative to the housing in the direction of the receptacle for the fluid product. There, it generally contacts a stopper in the receptacle, such that the movement of the advancing member also has the effect that the stopper in the receptacle is driven forward and the fluid product is discharged. The advancing member can be driven manually. However, it is also possible to provide a drive in the form of a pretensioned spring. Moreover, non-mechanical drives may be used, e.g. pneumatic drives. [0009] The actuation element for actuating the administering mechanism is movable relative to the housing, to be able to act on the administering mechanism. The actuation element can protrude from the housing in the form of a button. However, it is also possible to arrange the actuation element laterally on the housing, e.g. in the form of a slide or lever. The actuation element can be used to activate the administering mechanism, e.g. the advancing member, directly, or a pretensioned spring element can be released from its pretensioning and then act in turn on the advancing member. [0010] The fluid product is accommodated in the receptacle for receiving the fluid product. In some preferred embodiments, the fluid product is located or contained in a carpule or the like that can be inserted into the receptacle. Such carpules generally have a first end, closed off by a stopper, and a second end, closed off by a thin membrane through which a needle of an injection needle unit can be pushed for and/or during use. The receptacle with the carpule can be attached to the administering mechanism by inserting the receptacle into the housing or mounting it on the housing. [0011] To block or lock the actuation element, a device for administering a fluid product in accordance with the present invention has a blocking mechanism (which also may be thought of and/or referred to as a lock). The blocking mechanism prevents the actuation of the actuation element and, consequently, the actuation of the administering mechanism when the blocking mechanism is locked or located in a blocking position. The blocking mechanism can be moved from the blocking position to a release (released or unlocked) position in which the actuation element can be actuated to administer the fluid product by the administering mechanism. [0012] According to the present invention, the receptacle is mounted so as to be rotatable relative to the housing, the blocking mechanism being movable from the blocking position to the release position by rotation of the receptacle relative to the housing. The receptacle is in this case rotated, for example, about a longitudinal axis of the housing or of the receptacle. Thus, by the rotation of the receptacle, an injection pen in accordance with the present invention can be unlocked and the administering mechanism triggered using the actuation element. [0013] Locking and unlocking of the blocking mechanism in accordance with the present invention is advantageous when using two-chamber carpules which, for the mixing procedure, are turned or screwed into the housing of the administering device. In this case it is possible, by the rotation, to trigger the mixing procedure in the two-chamber carpule and also to move the blocking mechanism to the release or unlocked position. It is also possible for the receptacle to be arranged on or in the housing by a bayonet coupling, which bayonet coupling is also established by a rotation movement. In this rotation too, according to the present invention, the blocking mechanism can at the same time be moved to a release position. [0014] In some preferred embodiments, to move the blocking mechanism from the blocking position to the release position, the receptacle has an abutment and the blocking mechanism has a counter-abutment. The abutment of the receptacle and the counter-abutment of the blocking mechanism interact in such a way that, upon rotation of the receptacle relative to the housing, they contact each other and, upon further rotation of the receptacle, they entrain the blocking mechanism and move the latter from the blocking position to the release position. For this purpose, the blocking mechanism is rotatable, for example, relative to the housing in the circumferential direction of the housing. [0015] As soon as the blocking mechanism is located in the released or unlocked position, the actuation element can be activated. In some preferred embodiments, in the release position of the blocking mechanism, the actuation element may be moved relative to the housing along the longitudinal axis of the housing. For example, an actuation button protruding from the housing at one end is pressed or pushed into the housing. [0016] According to one embodiment of the present invention, the blocking mechanism is arranged on the actuation element. For example, the blocking mechanism and the actuation element can be structured as one piece. In this case, the blocking mechanism and the actuation element can be produced from a single section. However, it is also possible to subsequently secure the blocking mechanism on the actuation element. In one variant, the actuation element then moves along with the blocking mechanism when the blocking mechanism is moved from the blocking position to the release position. For example, the actuation element is rotated along with the rotation of the receptacle. [0017] In another variant, the blocking mechanism may be a flexible arm. The flexible arm can deflect in the circumferential direction of an axis of the actuation element, that is to say it can bend away from its rest position in a direction of rotation about the longitudinal axis. In this embodiment, the flexible arm forms the counter-abutment of the blocking mechanism, which counter-abutment interacts with the abutment of the receptacle. As the receptacle rotates, its abutment contacts the flexible arm and deflects the arm from the rest position, as a result of which the blocking mechanism is moved to a release position. [0018] In some preferred embodiments, the blocking or locking of the actuation element is effected by a blocking abutment on the blocking mechanism, which blocking abutment, in the blocking position, contacts a longitudinal abutment on the housing or a structure fixed to the housing in the longitudinal direction. A longitudinal abutment is to be understood as an abutment that blocks a movement along a longitudinal axis of the administering device. When the blocking abutment bears on the longitudinal abutment, the actuation element cannot be actuated in this longitudinal direction. The actuation element is therefore blocked against being pressed or pushed into the housing. This blocking is canceled by the deflection of the flexible arm, since the blocking abutment on the blocking mechanism is moved laterally away from the longitudinal abutment by the deflection of the flexible arm upon rotation of the receptacle. In the deflected position of the flexible arm, the blocking mechanism assumes a release or unlocked position. The blocking abutment can then be guided laterally past the longitudinal abutment in the longitudinal direction when the actuation element is moved into the housing. [0019] In another embodiment of the present invention, the blocking mechanism is designed as a rotary element that can be rotated relative to the actuation element. In this case, the blocking mechanism has a blocking abutment which, in the blocking position, contacts a longitudinal abutment on the actuation element, on the housing, or a part fixed to the housing. In this embodiment, the actuation element is therefore not movable in the longitudinal direction of the housing relative to the blocking mechanism in the blocking position. If the longitudinal abutment is provided on the actuation element, the rotary element is mounted rotatably in the housing such that it is not movable relative to the housing in the longitudinal direction. By rotating the rotary element by the rotation of the receptacle, the blocking abutment is removed from the longitudinal abutment on the actuation element, and the blocking is canceled. The actuation element can then be moved in the longitudinal direction relative to the housing and to the rotary element. [0020] If the longitudinal abutment is provided on the housing or on a part fixed to the housing, the rotary element is mounted rotatably in the housing such that, in the blocking position, it is rotatable relative to the housing but not longitudinally movable and, in the release position, can be moved in the longitudinal direction relative to the housing. The blocking thus acts between the blocking mechanism, in the form of the rotary element, and the housing. If the rotary element is rotated relative to the housing by the rotation of the receptacle, the blocking abutment is moved away from the longitudinal abutment on the housing or on the part fixed to the housing. The blocking mechanism can then be moved, together with the actuation element, relative to the housing in the longitudinal direction. Thus, in these variants too, the actuation element is prevented from being activated. The blocking mechanism and the rotary element are rotated by the rotation movement of the receptacle relative to the housing, by the abutment on the receptacle and the counter-abutment on the blocking mechanism. By this rotation, the abutment action between the blocking abutment of the blocking mechanism and the longitudinal abutment on the actuation element or on the housing or on the part fixed to the housing is canceled, and these abutments can be moved past one another in the longitudinal direction. Accordingly, in this position, the blocking mechanism is located in a release position in which the actuation element can be activated. [0021] In some embodiments, it may be advantageous if the rotary element of the blocking mechanism is secured in the blocking position. Such securing can, for example, be afforded by a press fit or by a pretensioning of a spring element. Upon rotation of the receptacle, the rotary element is then pushed out of the press fit or deflected counter to the spring tension. [0022] In some embodiments of the present invention, it is advantageous to provide a catch mechanism which locks the receptacle relative to the housing in the release position of the blocking mechanism. The locking action ensures that the receptacle does not rotate back in the opposite direction and cause the blocking mechanism to move from the release position back to a blocking position. Such a catch mechanism can, for example, be in the form of a snap-action or detent mechanism on the receptacle, which snaps into a recess on the housing. [0023] The present invention is advantageous when using a two-chamber carpule in a device for administering a fluid product. The receptacle for the two-chamber carpule has a thread, and the housing has a matching thread. Thus, the receptacle can be turned or screwed into the housing. When using the two-chamber carpule, the screwing of the receptacle into the housing can be used to mix the components or constituents of the fluid product in the two-chamber carpule. By screwing the receptacle into the housing, a first stopper in the two-chamber carpule is pushed forward (i.e., distally), e.g. by the advancing member of the administering mechanism. The forward movement is transferred via the solvent in the first chamber to the second stopper which separates the solvent chamber from the active substance chamber. The two stoppers are moved uniformly until the second stopper has arrived at a bypass in the carpule wall, through which bypass the solvent can run from the solvent chamber into the active substance chamber. The first stopper is pushed forward until the solvent is in the first chamber, and until the first stopper comes to lie on the second stopper. The screwing-in of the two-chamber carpule is such that the blocking mechanism is moved from the blocking position to the release position as soon as all of the solvent has passed from the solvent chamber to the active substance chamber. By the catch mechanism, the receptacle is locked relative to the housing in the release position of the blocking mechanism, such that the administering device, in this position, is ready for an injection, that is to say the active substance has been mixed completely and the blocking of the administering device is canceled. As soon as an injection needle unit is fitted onto the receptacle, an injection can be performed. In this embodiment, it is advantageous that no separate maneuver is needed to unlock the blocking mechanism, and instead the blocking action is canceled by the necessary mixing of the two-chamber carpule. BRIEF DESCRIPTION OF THE DRAWINGS [0024] FIG. 1 depicts an embodiment of an administering device in accordance with the present invention in a starting state, [0025] FIG. 2 shows the administering device in a state when mixing has taken place, [0026] FIG. 3 shows the administering device in a state when air has been removed, [0027] FIG. 4 shows the administering device in a triggered state, [0028] FIG. 5 shows the administering device in a state after a product has been discharged, [0029] FIG. 6 a is an inside view of the administering device in a blocking position, [0030] FIG. 6 b is an inside view of the administering device in a release position, [0031] FIG. 7 a is a detailed view of another embodiment of an administering device in a blocking position, and [0032] FIG. 7 b is a detailed view of the administering device of FIG. 7 a in a release or unlocked position. DETAILED DESCRIPTION [0033] With regard to fastening, mounting, attaching or connecting components of the present invention, unless specifically described as otherwise, conventional mechanical fasteners and methods may be used. Other appropriate fastening or attachment methods include adhesives, welding and soldering, the latter particularly with regard to the electrical system of the invention, if any. In embodiments with electrical features or components, suitable electrical components and circuitry, wires, wireless components, chips, boards, microprocessors, inputs, outputs, displays, control components, etc. may be used. Generally, unless otherwise indicated, the materials for making embodiments of the invention and/or components thereof may be selected from appropriate materials such as metal, metallic alloys, ceramics, plastics, etc. Unless otherwise indicated specifically or by context, positional terms (e.g., up, down, front, rear, distal, proximal, etc.) are descriptive not limiting. Same reference numbers are used to denote same parts or components. [0034] FIGS. 1 to 6 show an embodiment of an administering device according to the present invention with a blocking mechanism, or lock, for blocking an actuation element. FIGS. 7 a and 7 b show another embodiment of a blocking mechanism for blocking an actuation element. Each of FIGS. 1 to 5 shows two views, of which the second view at the bottom is turned through 90° in relation to the first view at the top. [0035] The administering device according to one embodiment of the present invention uses a two-chamber carpule as container for a fluid product. The fluid product is discharged from the carpule by a drive member being moved forward (distally) by a discharging spring. The product is therefore discharged automatically as soon as the discharging spring is activated. The administering device has a fixed dose, i.e. the discharge volume is fixed. The forward movement of the drive member is therefore also fixed and cannot be individually adjusted. The administering device is blocked or locked after a single discharge procedure and is discarded after the discharge procedure. [0036] It should be clear to a person skilled in the art that a blocking mechanism or lock according to the present invention can be used equally advantageously in reusable administering devices, in devices with individual dosing or manual discharge, and also in devices with single-chamber carpules. [0037] In the text below, the term distal (and terms front or forward) refer to the end of the administering device at which the fluid product is discharged, and the term proximal designates the opposite end (the rear or back end). [0038] The administering device according to one embodiment of the present invention has a housing 1 , a receptacle for receiving the fluid product or substance to be administered in the form of a carpule holder 2 , a drive member 3 with a holding mechanism in the form of holding arms 4 , a blocking mechanism in the form of a blocking ring 5 , and an actuation element in the form of a trigger button 6 . [0039] A two-chamber carpule 7 is accommodated in the carpule holder 2 . The two-chamber carpule has a first stopper 8 a and a second stopper 8 b . The second stopper 8 b closes the two-chamber carpule at the proximal end. At the distal end, the two-chamber carpule has a narrowed area whose opening is closed off by a membrane. The membrane can be pierced by a needle of an injection needle unit. The injection needle unit is not shown in the figures. A first chamber 9 a , in which a dry or lyophilized active substance is accommodated (not shown), is formed between the membrane and the first stopper 8 a . A second chamber, in which the solvent for the active substance is stored, is formed between the first stopper 8 a and the second stopper 8 b. [0040] The drive member 3 has a sleeve-shaped configuration. A drive spring 10 , arranged in the inside of the drive member 3 , is clamped between a distal abutment at the sleeve base of the drive member and a proximal abutment on an element 11 fixed to the housing. In the starting state in FIG. 1 , the drive member 3 is held relative to the housing element 11 by snap-action arms 12 , which releasably snap in behind an abutment of the housing element 11 . At the distal end of the drive member 3 , the holding arms 4 are mounted in such a way that they protrude or extend laterally from a longitudinal axis of the drive member in this starting position. In the embodiment depicted, two holding arms are shown spread apart from each other. It is of course also possible to provide three or more such holding arms 4 . In the starting state in FIG. 1 , the distal ends of the holding arms 4 abut against a proximal edge of the carpule 7 . The holding arms 4 press the carpule 7 against a shoulder 13 of the carpule holder 2 . The carpule 7 is therefore held in a defined (or certain or selected) position, relative to the carpule holder 2 , by the holding mechanism in the from of the holding arms 4 . This prevents the carpule from moving back and forth in the proximal and distal directions in the holder. [0041] In the starting state in FIG. 1 , the blocking ring 5 is located in a blocking position in which it blocks or prevents an actuation of the trigger button 6 , i.e. the trigger button 6 cannot be pressed in the longitudinal direction into the housing 1 . For this purpose, the blocking ring 5 has a blocking abutment 14 , which rests on a counter-abutment 15 on the trigger button 6 . By the blocking abutment 14 of the blocking ring 5 and the counter-abutment 15 of the trigger button 6 abutting or contacting each other, the trigger button 6 cannot be actuated, that is to say it cannot be pressed into the housing along the longitudinal axis of the housing. For this purpose, the blocking ring 5 is mounted fixedly relative to the housing in the longitudinal direction but can be rotated relative to the housing. The blocking abutment 14 can be formed, for example, by ribs or cams on the blocking ring or by the proximal edge of the blocking ring 5 . [0042] The blocking ring 15 has a sleeve-shaped configuration and surrounds the snap-action arms 12 of the drive member 3 . In the starting state in FIG. 1 , the inner circumferential surface of the blocking ring 5 bears on the outside of the snap-action arms 12 such that the arms cannot be released from their snap-in engagement behind the housing element 11 . The blocking ring 5 thus blocks an actuation of the trigger button 6 and also a release of the snap-action arms 12 . The starting state corresponds to a delivery or purchase state in which the administering device is supplied to a user. An actuation of the administering device is not possible in this state. [0043] FIG. 2 shows the administering device in a state when mixing has taken place, in which state the active substance of the chamber 9 a of the two-chamber carpule 7 has been mixed with the solvent of the chamber 9 b . The completion of the mixing procedure can be indicated by a tactile, acoustic or visual signal. As is shown in FIG. 2 , mixing was achieved by moving the stoppers 8 a and 8 b inside the carpule 7 until the stopper 8 a comes to lie on a bypass 16 through which the solvent can flow into the chamber 9 a and the stopper 8 b comes to lie on the stopper 8 a . For advancing the stoppers, the carpule holder 2 is screwed into the housing 1 such that the drive member, which in this state is at rest relative to the housing, moves the stoppers 8 a and 8 b relative to the carpule 7 . To screw the carpule holder in, an inner thread is provided on the inside of the housing and an outer thread is provided on the outside of the carpule holder. [0044] As can be seen in FIG. 2 , the holding arms 4 have slipped from the proximal edge of the carpule 7 and have been moved radially inwardly in the direction of the longitudinal axis of the drive member. For this purpose, the ends of the holding arms 4 have oblique surfaces along which the holding arms 4 are deflected inwardly as soon as the proximal edge of the carpule 7 is pressed with sufficient force against the oblique surfaces, as is the case when the carpule holder 2 is screwed into the housing 1 . The holding arms 4 move in toward each other and form a ram for the stopper 8 b of the carpule 7 . By the holding arms 4 abutting against the stopper 8 b , the carpule 7 is further held in its defined position in the carpule holder 2 , while the stoppers 8 a and 8 b are moved inside the carpule 7 . Independently of this, the holding arms 4 form a press fit with the inside wall of the carpule 7 , as they have radially outward pretensioning since having being bent radially inwardly. This press fit serves to hold the carpule in a defined or set position in the carpule holder. [0045] After the mixing has taken place in the two-chamber carpule, it may be necessary for the chamber 9 a , with the dissolved active substance, to have air removed from it before the active substance can be injected. For this purpose, an injection needle unit is mounted on the distal end of the carpule holder 2 , such that a needle pierces the membrane of the carpule 7 and thus creates a fluid connection to the chamber 9 a . Screwing in the carpule holder 2 slightly further leads to a further advance movement of the stoppers 8 a and 8 b , such that air located in the chamber 9 a can escape. The advance movement is normally carried out until a small amount of the active substance 9 a emerges from the needle of the injection needle unit. The completion of the air removal procedure, which also may be thought of and/or referred to as priming or a priming procedure, can be indicated by a tactile, acoustic or visual signal. [0046] The state with the air removed in shown in FIG. 3 . The injection needle unit is not shown. In the last screwing-in movement of the carpule holder 2 into the housing 1 , in which air can also be removed from the carpule, the blocking ring 5 is moved from the blocking position to the release position. As is shown in FIGS. 6 a - 6 d , the carpule holder for this purpose has an abutment 17 , and the blocking ring has a counter-abutment 18 . The abutment 17 of the carpule holder 2 is designed such that it abuts in the circumferential direction against the counter-abutment 18 of the blocking ring 5 during the rotation movement of the carpule holder. Upon further rotation of the carpule holder 2 , the carpule holder carries the blocking ring 5 along with it, such that the blocking ring 5 is rotated relative to the housing 1 and to the trigger button 6 . By this rotation movement, the blocking ring is moved from the blocking position to the release position. As is shown in FIG. 3 , during the rotation the blocking abutment 14 of the blocking ring 5 is rotated away from the counter-abutment 15 of the trigger button 6 until the counter-abutment 15 lies opposite a groove or channel 19 of the blocking ring, inside which groove or channel 19 the counter-abutment 15 of the trigger button 6 can be moved in the longitudinal direction. [0047] During the rotation of the blocking ring 5 by the carpule holder 2 , the inner surfaces of the blocking ring 5 , which prevent the snap-action arms 12 from disengaging from their snap-in position, are also rotated away from this position. In the release position of the blocking ring 5 , the snap-action arms 12 lie opposite recesses in the sleeve face of the blocking ring 5 . The blocking ring 5 is therefore also located in a release position with respect to the snap-action arms 12 . [0048] FIG. 4 shows the administering device in a triggered state in which the trigger button 6 has been pressed into the housing 1 generally along the longitudinal axis of the housing 1 . The counter-abutments 15 of the trigger button 6 have been moved inside the channels 19 of the blocking ring 5 . The trigger button 6 has inwardly extending webs 20 which, when the trigger button is in the triggered or pushed-in state, bear against oblique surfaces on the proximal end of the snap-action arms 12 and spread the arms 12 radially outwardly as the trigger button 6 moves forward, such that the ends of the snap-action arms come to lie inside the recesses in the blocking ring 5 . The securing of the drive member 3 on the housing element 11 is canceled by the spreading-open of the snap-action arms 12 . In the triggered state, the spring force of the drive spring 10 begins to act and presses against the drive member 3 . [0049] As is shown in FIG. 5 , the drive member 3 is moved forward relative to the carpule 7 by the force of the spring 10 and drives the stoppers 8 a and 8 b inside the carpule 7 , such that the active substance is discharged from the chamber 9 a . The drive spring 10 pushes the drive member 3 forward into the carpule until a projection 21 , provided on the drive member 3 , abuts against an edge of the housing element 11 . As soon as the projection 21 abuts against the housing element 11 , the discharging of the active substance is ended. [0050] In the illustrative embodiment shown, a flexible arm 22 , provided on the drive member 3 , protrudes into and/or lodges in a recess in the carpule holder, when the discharging has ended, and serves to block or prevent a movement of the drive member 3 in the proximal direction. Moreover, when it catches in the recess of the carpule holder, the arm 22 produces an acoustic noise, which indicates that the discharging has been completed. [0051] FIGS. 7 a and 7 b show another embodiment of an administering device with a blocking mechanism according to the present invention. In this variant, the blocking mechanism is arranged on the actuation element, which is in the form of the trigger button. As is shown in FIG. 7 a , a locking arm 23 protrudes or extends from the trigger button 6 in the longitudinal direction of the administering device. The locking arm 23 and the trigger button 6 are one piece or integrally connected. A blocking abutment 24 , which abuts in the longitudinal direction against a longitudinal abutment of the housing element 11 , is provided on the locking arm 23 . Because of the contact of the blocking abutment 24 with the longitudinal abutment 25 , the trigger button 6 cannot be pressed in the longitudinal direction into the housing 1 . [0052] In FIG. 7 b , the carpule holder 2 has already been screwed into the housing 1 . The carpule holder 2 is screwed into the housing until an abutment 17 ′ of the carpule holder abuts in the circumferential direction against a counter-abutment 18 ′ of the locking arm 23 of the trigger button 6 . Upon further rotation of the carpule holder 2 , the locking arm 23 is deflected in the circumferential direction relative to its rest position, since the abutment 17 ′ acts against the counter-abutment 18 ′. The blocking abutment of the trigger button 6 is in this way deflected from its blocking position relative to the longitudinal abutment 25 of the housing element 11 and comes to lie opposite a recess in the housing element 11 . The blocking mechanism for blocking the trigger button 6 is now located in a release position in which the trigger button 6 can be pressed into the housing 1 along the longitudinal axis. The blocking abutment 24 is guided through the recess in the housing element 11 . [0053] In this embodiment, the carpule holder 2 has a catch mechanism with which it locks relative to the housing as soon as the blocking mechanism is in a release position, such that a reverse rotation of the carpule holder and consequently a renewed blocking of the trigger button are prevented. [0054] Embodiments of the present invention, including preferred embodiments, have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms and steps disclosed. The embodiments were chosen and described to illustrate the principles of the invention and the practical application thereof, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth they are fairly, legally, and equitably entitled.

An apparatus for administering a fluid product, including a housing, an administering mechanism accommodated in the housing, an actuation element for actuating the administering mechanism, a receptacle for holding the fluid product, and a lock for releasably locking the actuation element, wherein the receptacle is rotatable relative to the housing and the lock can be moved from a locked position to an unlocked position by rotating the receptacle.

[0001] This application is a continuation of U.S. patent application Ser. No. 14/204,930, filed Mar. 11, 2014, (now U.S. Pat. No. 9,398,594), which is a continuation of U.S. patent application Ser. No. 13/301,610, filed on Nov. 21, 2011, (now U.S. Pat. No. 8,687,642), which is a continuation of U.S. patent application Ser. No. 11/865,685, filed on Oct. 1, 2007, (now U.S. Pat. No. 8,130,770), which is a continuation of U.S. patent application Ser. No. 10/187,132, filed on Jun. 28, 2002, (now U.S. Pat. No. 7,277,413) and which claims priority from: [0002] [1] U.S. Provisional Application Ser. No. 60/302,661, filed Jul. 5, 2001, entitled “HCF ACCESS THROUGH TIERED CONTENTION,” [0003] [2] U.S. Provisional Application Ser. No. 60/304,122, filed Jul. 11, 2001, entitled “HCF ACCESS THROUGH TIERED CONTENTION,” and [0004] [3] U.S. Provisional Application Ser. No. 60/317,933 filed Sep. 10, 2001, entitled “HCF ACCESS AND OVERLAPPED BSS MITIGATION,” all of which are incorporated herein by reference. RELATED APPLICATIONS [0005] This patent application is related to the copending regular U.S. patent application Ser. No. 09/985,257, filed Nov. 2, 2001, by Mathilde Benveniste, entitled “TIERED CONTENTION MULTIPLE ACCESS (TCMA): A METHOD FOR PRIORITY-BASED SHARED CHANNEL ACCESS,” (now U.S. Pat. No. 7,095,754) which is incorporated by reference. FIELD OF THE INVENTION [0006] The invention disclosed broadly relates to telecommunications methods and more particularly relates to Quality of Service (QoS) management in multiple access packet networks. BACKGROUND OF THE INVENTION [0007] Wireless Local Area Networks (WLANS) [0008] Wireless local area networks (WLANs) generally operate at peak speeds of between 10 to 100 Mbps and have a typical range of 100 meters. Single cell Wireless LANs, are suitable for small single-floor offices or stores. A station in a wireless LAN can be a personal computer, a bar code scanner, or other mobile or stationary device that uses a wireless network interface card (NIC) to make the connection, over the RF link to other stations in the network. The single-cell wireless LAN provides connectivity within radio range between wireless stations. An access point allows connections via the backbone network, to wired network-based resources, such as servers. A single cell wireless LAN can typically support up to 25 users and still keep network access delays at an acceptable level. Multiple cell wireless LANs provide greater range than does a single cell, by means of a set of access points and a wired network backbone to interconnect a plurality of single cell LANs. Multiple cell wireless LANs can cover larger multiple-floor buildings. A mobile laptop computer or data collector with a wireless network interface card (NIC) can roam within the coverage area while maintaining a live connection to the backbone network. [0009] Wireless LAN specifications and standards include the IEEE 802.11 Wireless LAN Standard and the HIPERLAN Type 1 and Type 2 Standards. The IEEE 802.11 Wireless LAN Standard is published in three parts as IEEE 802.11-1999; IEEE 802.11a-1999; and IEEE 802.11b-1999, which are available from the IEEE, Inc. web site http://grouper.ieee.org/groups/802/11. An overview of the HIPERLAN Type 1 principles of operation is provided in the publication HIPERLAN Type 1 Standard, ETSI ETS 300 652, WA2 Dec. 1997. An overview of the HIPERLAN Type 2 principles of operation is provided in the Broadband Radio Access Networks (BRAN), HIPERLAN Type 2; System Overview, ETSI TR 101 683 VI.I.1 (2000-02) and a more detailed specification of its network architecture is described in HIPERLAN Type 2, Data Link Control (DLC) Layer; Part 4. Extension for Home Environment, ETSI TS 101 761-4 V1.2.1 (2000-12). A subset of wireless LANs is Wireless Personal Area Networks (PANs), of which the Bluetooth Standard is the best known. The Bluetooth Special Interest Group, Specification Of The Bluetooth System, Version 1.1, Feb. 22, 2001, describes the principles of Bluetooth device operation and communication protocols. [0010] The IEEE 802.11 Wireless LAN Standard defines at least two different physical (PHY) specifications and one common medium access control (MAC) specification. The IEEE 802.11(a) Standard is designed to operate in unlicensed portions of the radio spectrum, usually either in the 2.4 GHz Industrial, Scientific, and Medical (ISM) band or the 5 GHz Unlicensed-National Information Infrastructure (U-NIT) band. It uses orthogonal frequency division multiplexing (OFDM) to deliver up to 54 Mbps data rates. The IEEE 802.11(b) Standard is designed for the 2.4 GHz ISM band and uses direct sequence spread spectrum (DSSS) to deliver up to 11 Mbps data rates. The IEEE 802.11 Wireless LAN Standard describes two major components, the mobile station and the fixed access point (AP). IEEE 802.11 networks can also have an independent configuration where the mobile stations communicate directly with one another, without support from a fixed access point. [0011] A single cell wireless LAN using the IEEE 802.11 Wireless LAN Standard is an Independent Basic Service Set (MSS) network. An MSS has an optional backbone network and consists of at least two wireless stations. A multiple cell wireless LAN using the IEEE 802.11 Wireless LAN Standard is an Extended Service Set (ESS) network. An ESS satisfies the needs of large coverage networks of arbitrary size and complexity. [0012] Each wireless station and access point in an IEEE 802.11 wireless LAN implements the MAC layer service, which provides the capability for wireless stations to exchange MAC frames. The MAC frame transmits management, control, or data between wireless stations and access points. After a station forms the applicable MAC frame, the frame's bits are passed to the Physical Layer for transmission. [0013] Before transmitting a frame, the MAC layer must first gain access to the network. Three interframe space (IFS) intervals defer an IEEE 802.11 station's access to the medium and provide various levels of priority. Each interval defines the duration between the end of the last symbol of the previous frame, to the beginning of the first symbol of the next frame. The Short Interframe Space (SIFS) provides the highest priority level by allowing some frames to access the medium before others, such as an Acknowledgement (ACK) frame, a Clear to Send (CTS) frame, or a subsequent fragment burst of a previous data frame. These frames require expedited access to the network to minimize frame retransmissions. [0014] The Priority Interframe Space (PIFS) is used for high priority access to the medium during the contention-free period. The point coordinator in the access point connected to backbone network, controls the priority-based Point Coordination Function (PCF) to dictate which stations in cell can gain access to the medium. The point coordinator in the access point sends a contention-free poll frame to a station, granting the station permission to transmit a single frame to any destination. All other stations in the cell can only transmit during contention-free period if the point coordinator grants them access to the medium. The end of the contention-free period is signaled by the contention-free end frame sent by the point coordinator, which occurs when time expires or when the point coordinator has no further frames to transmit and no stations to poll. [0015] The distributed coordination function (DCF) Interframe Space (DIFS) is used for transmitting low priority data frames during the contention-based period. The DIFS spacing delays the transmission of lower priority frames to occur later than the priority-based transmission frames. An Extended Interframe Space (EIFS) goes beyond the time of a DIFS interval, as a waiting period when a bad reception occurs. The EIFS interval provides enough time for the receiving station to send an acknowledgment (ACK) frame. [0016] During the contention-based period, the distributed coordination function (DCF) uses the Carrier-Sense Multiple Access With Collision Avoidance (CSMA/CA) contention-based protocol, which is similar to IEEE 802.3 Ethernet. The CSMA/CA protocol minimizes the chance of collisions between stations sharing the medium, by waiting a random backoff interval, if the station's sensing mechanism indicates a busy medium. The period of time immediately following traffic on the medium is when the highest probability of collisions occurs, especially where there is high utilization. Once the medium is idle, CSMA/CA protocol causes each station to delay its transmission by a random backoff time, thereby minimizing the chance it will collide with those from other stations. [0017] The CSMA/CA protocol computes the random backoff time as the product of a constant, the slot time, times a pseudo-random number RN which has a range of values from zero to a collision window CW. The value of the collision window for the first try to access the network is CW1, which yields the first try random backoff time. If the first try to access the network by a station fails, then the CSMA/CA protocol computes a new CW by doubling the current value of CW as CW2=CW1 times 2. The value of the collision window for the second try to access the network is CW2, which yields the second try random backoff time. This process by the CSMA/CA protocol of increasing the delay before transmission is called binary exponential backoff. The reason for increasing CW is to minimize collisions and maximize throughput for both low and high network utilization. Stations with low network utilization are not forced to wait very long before transmitting their frame. On the first or second attempt, a station will make a successful transmission. However, if the utilization of the network is high, the CSMA/CA protocol delays stations for longer periods to avoid the chance of multiple stations transmitting at the same time. If the second try to access the network fails, then the CSMA/CA protocol computes a new CW by again doubling the current value of CW as CW3=CW1 times 4. The value of the collision window for the third try to access the network is CW3, which yields the third try random backoff time. The value of CW increases to relatively high values after successive retransmissions, under high traffic loads. This provides greater transmission spacing between stations waiting to transmit. Collision Avoidance Techniques [0018] Four general collision avoidance approaches have emerged: [1] Carrier Sense Multiple Access (CSMA) [see, F. Tobagi and L. Kleinrock, “Packet Switching in Radio Channels: Part I—Carrier Sense Multiple Access Models and their Throughput Delay Characteristics”, IEEE Transactions on Communications, Vol 23, No 12, Pages 1400-1416, 1975], [2] Multiple Access Collision Avoidance (MACA) [see, P. Karn, “MACA—A New Channel Access Protocol for Wireless Ad-Hoc Networks”, Proceedings of the ARRL/CRRL Amateur Radio Ninth Computer Networking Conference, Pages 134-140, 1990], [3] their combination CSMA/CA, and [4] collision avoidance tree expansion. [0019] CSMA allows access attempts after sensing the channel for activity. Still, simultaneous transmit attempts lead to collisions, thus rendering the protocol unstable at high traffic loads. The protocol also suffers from the hidden terminal problem. [0020] The latter problem was resolved by the MACA protocol, which involves a three-way handshake [P. Karn, supra]. The origin node sends a request to send (RTS) notice of the impending transmission. A response is returned by the destination if the RTS notice is received successfully and the origin node proceeds with the transmission. This protocol also reduces the average delay as collisions are detected upon transmission of merely a short message, the RTS. With the length of the packet included in the RTS and echoed in the clear to send (CTS) messages, hidden terminals can avoid colliding with the transmitted message. However, this prevents the back-to-back re-transmission in case of unsuccessfully transmitted packets. A five-way handshake MACA protocol provides notification to competing sources of the successful termination of the transmission. [see, V. Bharghavan, A. Demiers, S. Shenker, and L. Zhang, “MACAW: A media access protocol for wireless LANs, SIGCOMM '94, Pages 212-225, ACM, 1994.] [0021] CSMA and MACA are combined in CSMA/CA, which is MACA with carrier sensing, to give better performance at high loads. A four-way handshake is employed in the basic contention-based access protocol used in the Distributed Coordination Function (DCF) of the IEEE 802.11 Standard for Wireless LANs. [see, IEEE Standards Department, D3, “Wireless Medium Access Control and Physical Layer WG,” IEEE Draft Standard P802.11 Wireless LAN, January 1996.] [0022] Collisions can be avoided by splitting the contending terminals before transmission is attempted. In the pseudo-Bayesian control method, each terminal determines whether it has permission to transmit using a random number generator and a permission probability “p” that depends on the estimated backlog. [see, R. L. Rivest, “Network control by Bayesian Broadcast”, IEEE Trans. Inform. Theory, Vol IT 25, pp. 505-515, September 1979] [0023] To resolve collisions, subsequent transmission attempts are typically staggered randomly in time using the following two approaches: binary tree and binary exponential backoff. [0024] Upon collision, the binary tree method requires the contending nodes to self-partition into two groups with specified probabilities. This process is repeated with each new collision. The order in which contending nodes transmit is determined either by serial or parallel resolution of the tree. [see, J. L. Massey, “Collision-resolution algorithms and random-access communications”, in Multi-User Communication Systems, G. Longo (ed.), CISM Courses and Lectures No. 265. New York: Springer 1982, pp. 73-137.] [0025] In the binary exponential backoff approach, a backoff counter tracks the number of pauses and hence the number of completed transmissions before a node with pending packets attempts to seize the channel. A contending node initializes its backoff counter by drawing a random value, given the backoff window size. Each time the channel is found idle, the backoff counter is decreased and transmission is attempted upon expiration of the backoff counter. The window size is doubled every time a collision occurs, and the backoff countdown starts again. [see, A. Tanenbaum, Computer Networks, 3 rd ed., Upper Saddle River, N.J., Prentice Hall, 1996] The Distributed Coordination Function (DCF) of the IEEE 802.11 Standard for Wireless LANs employs a variant of this contention resolution scheme, a truncated binary exponential backoff, starting at a specified window and allowing up to a maximum backoff range below which transmission is attempted. [IEEE Standards Department, D3, supra] Different backoff counters may be maintained by a contending node for traffic to specific destinations. [Bharghavan, supra] [0026] In the IEEE 802.11 Standard, the channel is shared by a centralized access protocol, the Point Coordination Function (PCF), which provides contention-free transfer based on a polling scheme controlled by the access point (AP) of a basic service set (BSS). [IEEE Standards Department, D3, supra] The centralized access protocol gains control of the channel and maintains control for the entire contention-free period by waiting a shorter time between transmissions than the stations using the Distributed Coordination Function (DCF) access procedure. Following the end of the contention-free period, the DCF access procedure begins, with each station contending for access using the CSMA/CA method. [0027] The 802.11 MAC Layer provides both contention and contention-free access to the shared wireless medium. The MAC Layer uses various MAC frame types to implement its functions of MAC management, control, and data transmission. Each station and access point on an 802.11 wireless LAN implements the MAC Layer service, which enables stations to exchange packets. The results of sensing the channel to determine whether the medium is busy or idle, are sent to the MAC coordination function of the station. The MAC coordination also carries out a virtual carrier sense protocol based on reservation information found in the Duration Field of all frames. This information announces to all other stations, the sending station's impending use of the medium. The MAC coordination monitors the Duration Field in all MAC frames and places this information in the station's Network Allocation Vector (NAV) if the value is greater than the current NAV value. The NAV operates similarly to a timer, starting with a value equal to the Duration Field of the last frame transmission sensed on the medium, and counting down to zero. After the NAV reaches zero, the station can transmit, if its physical sensing of the channel indicates a clear channel. [0028] At the beginning of a contention-free period, the access point senses the medium, and if it is idle, it sends a Beacon packet to all stations. The Beacon packet contains the length of the contention-free interval. The MAC coordination in each member station places the length of the contention-free interval in the station's Network Allocation Vector (NAV), which prevents the station from taking control of the medium until the end of the contention-free period. During the contention-free period, the access point can send a polling message to a member station, enabling it to send a data packet to any other station in the BSS wireless cell. Quality of Service (QoS) [0029] Quality of service (QoS) is a measure of service quality provided to a customer. The primary measures of QoS are message loss, message delay, and network availability. Voice and video applications have the most rigorous delay and loss requirements. Interactive data applications such as Web browsing have less restrained delay and loss requirements, but they are sensitive to errors. Non-real-time applications such as file transfer, Email, and data backup operate acceptably across a wide range of loss rates and delay. Some applications require a minimum amount of capacity to operate at all, for example, voice and video. Many network providers guarantee specific QoS and capacity levels through the use of Service-Level Agreements (SLAs). An SLA is a contract between an enterprise user and a network provider that specifies the capacity to be provided between points in the network that must be delivered with a specified QoS. If the network provider fails to meet the terms of the SLA, then the user may be entitled a refund. The SLA is typically offered by network providers for private line, frame relay, ATM, or Internet networks employed by enterprises. [0030] The transmission of time-sensitive and data application traffic over a packet network imposes requirements on the delay or delay jitter, and the error rates realized; these parameters are referred to generically as the QoS (Quality of Service) parameters. Prioritized packet scheduling, preferential packet dropping, and bandwidth allocation are among the techniques available at the various nodes of the network, including access points, that enable packets from different applications to be treated differently, helping achieve the different quality of service objectives. Such techniques exist in centralized and distributed variations. The concern herein is with distributed mechanisms for multiple access in cellular packet networks or wireless ad hoc networks. [0031] Management of contention for the shared transmission medium must reflect the goals sought for the performance of the overall system. For instance, one such goal would be the maximization of goodput (the amount of good data transmitted as a fraction of the channel capacity) for the entire system, or of the utilization efficiency of the RF spectrum; another is the minimization of the worst-case delay. As multiple types of traffic with different performance requirements are combined into packet streams that compete for the same transmission medium, a multi-objective optimization is required. [0032] Ideally, one would want a multiple access protocol that is capable of effecting packet transmission scheduling as close to the optimal scheduling as possible, but with distributed control. Distributed control implies both some knowledge of the attributes of the competing packet sources and limited control mechanisms. [0033] To apply any scheduling algorithm in random multiple access, a mechanism must exist that imposes an order in which packets will seize the medium. For distributed control, this ordering must be achieved independently, without any prompting or coordination from a control node. Only if there is a reasonable likelihood that packet transmissions will be ordered according to the scheduling algorithm, can one expect that the algorithm's proclaimed objective will be attained. [0034] The above cited, copending patent application by Mathilde Benveniste, entitled “Tiered Contention Multiple Access (TCMA): A Method for Priority-Based Shared Channel Access”, describes the Tiered Contention Multiple Access (TCMA) distributed medium access protocol that schedules transmission of different types of traffic based on their QoS service quality specifications. This protocol makes changes to the contention window following the transmission of a frame, and therefore is also called Extended-DCF (E-DCF). During the contention window, the various stations on the network contend for access to the network. To avoid collisions, the MAC protocol requires that each station first wait for a randomly-chosen time period, called an arbitration time. Since this period is chosen at random by each station, there is less likelihood of collisions between stations. TCMA uses the contention window to give higher priority to some stations than to others. Assigning a short contention window to those stations that should have higher priority ensures that in most cases, the higher-priority stations will be able to transmit ahead of the lower-priority stations. TCMA schedules transmission of different types of traffic based on their QoS service quality specifications. As seen in FIG. 1 , which depicts the tiered contention mechanism, a station cannot engage in backoff countdown until the completion of an idle period of length equal to its arbitration time. [0035] The above cited, copending patent application by Mathilde Benveniste also applies TCMA to the use of the wireless access point as a traffic director. This application of the TCMA protocol is called the hybrid coordination function (HCF). In HCF, the access point uses a polling technique as the traffic control mechanism. The access point sends polling packets to a succession of stations on the network. The individual stations can reply to the poll with a packet that contains not only the response, but also any data that needs to be transmitted. Each station must wait to be polled. The access point establishes a polling priority based on the QoS priority of each station. [0036] What is needed in the prior art is a way to apply the hybrid coordination function (HCF) to wireless cells that have overlapping access points contending for the same medium. SUMMARY OF THE INVENTION [0037] In accordance with the invention, the Tiered Contention Multiple Access (TCMA) protocol is applied to wireless cells which have overlapping access points contending for the same medium. Quality of Service (QoS) support is provided to overlapping access points to schedule transmission of different types of traffic based on the service quality specifications of the access points. [0038] The inventive method reduces interference in a medium between overlapping wireless LAN cells, each cell including an access point station and a plurality of member stations. In accordance with the invention, the method assigns to a first access point station in a first wireless LAN cell, a first scheduling tag. The scheduling tag has a value that determines an accessing order for the cell in a transmission frame, with respect to the accessing order of other wireless cells. The scheduling tag value is deterministically set. The scheduling tag value can be permanently assigned to the access point by its manufacturer, it can be assigned by the network administrator at network startup, it can be assigned by a global processor that coordinates a plurality of wireless cells over a backbone network, it can be drawn from a pool of possible tag values during an initial handshake negotiation with other wireless stations, or it can be cyclically permuted in real-time, on a frame-by-frame basis, from a pool of possible values, coordinating that cyclic permutation with that of other access points in other wireless cells. [0039] An access point station in a wireless cell signals the beginning of an intra-cell contention-free period for member stations in its cell by transmitting a beacon packet. The duration of the intra-cell contention-free period is deterministically set. The member stations in the cell store the intra-cell contention-free period value as a Network Allocation Vector (NAV). Each member station in the cell decrements the value of the NAV in a manner similar to other backoff time values, during which it will delay accessing the medium. [0040] In accordance with the invention, the method assigns to the first access point station, a first inter-cell contention-free period value, which gives notice to any other cell receiving the beacon packet, that the first cell has seized the medium for the period of time represented by the value. The inter-cell contention-free period value is deterministically set. Further in accordance with the invention, any station receiving the beacon packet immediately broadcasts a contention-free time response (CFTR) packet containing a copy of the first inter-cell contention-free period value. In this manner, the notice is distributed to a second access point station in an overlapping, second cell. The second access point stores the first inter-cell contention-free period value as an Inter-BSS Network Allocation Vector (IBNAV). The second access point decrements the value of IBNAV in a manner similar to other backoff time values, during which it will delay accessing the medium. [0041] Still further in accordance with the invention, the method also assigns to first member stations in the first cell, a first shorter backoff value for high Quality of Service (QoS) data and a first longer backoff value for lower QoS data. The backoff time is the interval that a member station waits after the expiration of the contention-free period, before the member station contends for access to the medium. Since more than one member station in a cell may be competing for access, the actual backoff time for a particular station can be selected as one of several possible values. In one embodiment, the actual backoff time for each particular station is deterministically set, so as to reduce the length of idle periods. In another embodiment, the actual backoff time for each particular station is randomly drawn from a range of possible values between a minimum delay interval to a maximum delay interval. The range of possible backoff time values is a contention window. The backoff values assigned to a cell may be in the form of a specified contention window. High QoS data is typically isochronous data such as streaming video or audio data that must arrive at its destination at regular intervals. Low QoS data is typically file transfer data and email, which can be delayed in its delivery and yet still be acceptable. The Tiered Contention Multiple Access (TCMA) protocol coordinates the transmission of packets within a cell, so as to give preference to high QoS data over low QoS data, to insure that the required quality of service is maintained for each type of data. [0042] The method similarly assigns to a second access point station in a second wireless LAN cell that overlaps the first cell, a second contention-free period value longer than the first contention-free period value. The method also assigns to second member stations in the second cell, a second shorter backoff value for high QoS data and a second longer backoff value for lower QoS data. The first and second cells are considered to be overlapped when one or more stations in the first cell inadvertently receive packets from member stations or the access point of the other cell. The invention reduces the interference between the overlapped cells by coordinating the timing of their respective transmissions, while maintaining the TCMA protocol's preference for the transmission of high QoS data over low QoS data in each respective cell. [0043] During the operation of two overlapped cells, the method transmits a first beacon packet including the intra-cell contention-free period value (the increment to the NAV) and inter-cell contention-free period value (the CFTR), from the first access point to the first member stations in the first cell. The beacon packet is received by the member stations of the first cell and can be inadvertently received by at least one overlapped member station of the second cell. Each member station in the first cell increments its NAV with the intra-cell contention-free period value and stores the inter-cell contention-free period value as the CFTR. [0044] In accordance with the invention, each station that receives the first beacon packet, immediately responds by transmitting a first contention-free time response (CFTR) packet that contains a copy of the inter-cell contention-free period value (CFTR). A CFTR packet is transmitted from the first member stations in the first cell and also by the overlapped member stations of the second cell. The effect of the transmission of CFTR packets from member stations in the second cell is to alert the second access point and the second member stations in the second cell, that the medium has been seized by the first access point in the first cell. When the second access point in the second cell receives the CFTR packet it stores a copy of the inter-cell contention-free period value as the IBNAV. [0045] Similar to a station's Network Allocation Vector (NAV), a first IBNAV is set at the second access point to indicate the time the medium will be free again. Also similar to the NAV, the first IBNAV is decremented with each succeeding slot, similar to the decrementing of other backoff times. When the second access point receives the first IBNAV representing the first cell's contention-free period value, the second access point must respect the first IBNAV value and delay transmitting its beacon packet and the exchange of other packets in the second cell until the expiration of the received, first IBNAV. [0046] When the second access point has decremented the first IBNAV to zero, the second access point transmits its second beacon packet including its second contention-free period values of NAV and a second IBNAV, to the second member stations in the second cell. Each station that receives the second beacon packet immediately responds by transmitting a second contention-free time response (CFTR) packet that contains a copy of the second IBNAV inter-cell contention-free period value. The second CFTR packet is transmitted from the second member stations in the second cell and also by the overlapped member stations of the first cell. The effect of the transmission of the second CFTR packets from overlapped member stations in the first cell is to alert the first access point and the first member stations in the first cell, that the medium has been seized by the second access point in the second cell. When the first access point in the first cell receives the CFTR packet it stores the a copy of the second IBNAV inter-cell contention-free period value, to indicate the time the medium will be free again. The second IBNAV is decremented with each succeeding frame, similar to the decrementing of other backoff times. [0047] The second member stations in the second cell wait for completion of the countdown of their NAVs to begin the TCMA protocol of counting down the second shorter backoff for high QoS data and then transmitting second high QoS data packets. [0048] Meanwhile, the first access point in the first cell waits for completion of the countdown of the second IBNAV inter-cell contention-free period before starting the countdown of its own NAV for its own intra-cell contention-free period. The first member stations in the first cell wait for the countdown of their NAVs, to begin the TCMA protocol of counting down the first longer backoff for low QoS data and then transmitting first low QoS data. [0049] Meanwhile the second member stations are waiting for the TCMA protocol of counting down the second longer backoff for lower QoS data before transmitting the second lower QoS data. [0050] In this manner, interference in a medium between overlapping wireless LAN cells is reduced. [0051] Potential collisions between cells engaged in centralized access can be averted or resolved by the TCMA protocol. In accordance with the invention, deterministically set backoff delays are used, which tend to reduce the length of the idle periods. The possibility of coincident or overlapping contention-free periods between neighboring cells is eliminated through the use of an “interference sensing” method employing a new frame. [0052] The invention enables communication of channel occupancy information to neighboring access points. When a beacon packet is transmitted, and before transmission of any other data or polling packets, all stations hearing the beacon will respond by sending a frame, the contention-free time response (CFTR), that will contain the duration of the contention-free period found in the beacon. An access point in neighboring cells, or stations attempting contention-based channel access, which receive this message from a station in the cell overlapping region, are thus alerted that the channel has been seized by an access point. Similar to a station's Network Allocation Vector (NAV), an Inter-Cell Network Allocation Vector at the access point accordingly indicates when the time the channel will be free again. Unless the Inter-Cell Network Allocation Vector is reset, the access point will decrease its backoff value only after the expiration of the Inter-Cell Network Allocation Vector, according to the backoff countdown rules. [0053] In another aspect of the invention, potential collisions between different access points engaged in centralized access cart be averted or resolved by using deterministic backoff delays, which avoid collisions between access points, and eliminate gaps between consecutive poll/response exchanges or contention-free bursts (CFBs) between the access point and its associated stations. [0054] The resulting invention applies the Tiered Contention Multiple Access (TCMA) protocol to wireless cells which have overlapping access points contending for the same medium. DESCRIPTION OF THE FIGURES [0055] FIG. 1 depicts the tiered contention mechanism. [0056] FIG. 1A through 1J show the interaction of two wireless LAN cells which have overlapping access points contending for the same medium, in accordance with the invention. [0057] FIG. 1K shows a timing diagram for the interaction of two wireless LAN cells in FIG. 1A through 1J , in accordance with the invention. [0058] FIG. 1L shows the IEEE 802.11 packet structure for a beacon packet, including the increment to the NAV period and the CFTR period, in accordance with the invention. [0059] FIG. 1M shows the IEEE 802.11 packet structure for a CFTR packet, including the CFTR period, in accordance with the invention. [0060] FIG. 2 illustrates the ordering of transmissions from three groups of BSSs. [0061] FIG. 3 illustrates how three interfering BSSs share the same channel for two consecutive frames. [0062] FIG. 4 illustrates how three interfering BSSs, each with two types of traffic of different priorities, share the same channel in two consecutive frames. [0063] FIGS. 5 ( 5 a and 5 b ) illustrates the possible re-use of tags. [0064] FIG. 6 illustrates the deterministic post-backoff. [0065] FIG. 7 shows the relationships of repeating sequences of CFBs. [0066] FIG. 8 illustrates the role of pegging in a sequence of CFBs by three overlapping access points. [0067] FIG. 9 illustrates the start-up procedure for a new access point, HC2, given an existing access point, HC1. [0068] FIG. 10 shows the relationship of repeating sequences of Tier I CFBs. [0069] FIG. 11 illustrates the start-up procedure for a new access point, HC2, given an existing access point, HC1. DISCUSSION OF THE PREFERRED EMBODIMENT [0070] The invention disclosed broadly relates to telecommunications methods and more particularly relates to Quality-of-Service (QoS) management in multiple access packet networks. Several protocols, either centralized or distributed can co-exist on the same channel through the Tiered Contention Multiple Access method. The proper arbitration time to be assigned to the centralized access protocol must satisfy the following requirements: (i) the centralized access protocol enjoys top priority access, (ii) once the centralized protocol seizes the channel, it maintains control until the contention-free period ends, (iii) the protocols are backward compatible, and (iv) Overlapping Basic Service Sets (OBSSs) engaged in centralized-protocol can share the channel efficiently. [0071] In accordance with the invention, the Tiered Contention Multiple Access (TCMA) protocol is applied to wireless cells which have overlapping access points contending for the same medium. Quality of Service (QoS) support is provided to overlapping access points to schedule transmission of different types of traffic based on the service quality specifications of the access points. [0072] The inventive method reduces interference in a medium between overlapping wireless LAN cells, each cell including an access point station and a plurality of member stations. FIGS. 1A through 1J show the interaction of two wireless LAN cells which have overlapping access points contending for the same medium, in accordance with the invention. The method assigns to a first access point station in a first wireless LAN cell, a first scheduling tag. The scheduling tag has a value that determines an accessing order for the cell in a transmission frame, with respect to the accessing order of other wireless cells. The scheduling tag value is deterministically set. The scheduling tag value can be permanently assigned to the access point by its manufacturer, it can be assigned by the network administrator at network startup, it can be assigned by a global processor that coordinates a plurality of wireless cells over a backbone network, it can be drawn from a pool of possible tag values during an initial handshake negotiation with other wireless stations, or it can be cyclically permuted in real-time, on a frame-by-frame basis, from a pool of possible values, coordinating that cyclic permutation with that of other access points in other wireless cells. [0073] The interaction of the two wireless LAN cells 100 and 150 in FIGS. 1A through 1J is shown in the timing diagram of FIG. 1K . The timing diagram of FIG. 1K begins at instant T0, goes to instant T9, and includes periods P1 through P8, as shown in the figure. The various packets discussed below are also shown in FIG. 1K , placed at their respective times of occurrence. An access point station in a wireless cell signals the beginning of an intra-cell contention-free period for member stations in its cell by transmitting a beacon packet. FIG. 1A shows access point 152 of cell 150 connected to backbone network 160 , transmitting the beacon packet 124 . In accordance with the invention, the beacon packet 124 includes two contention-free period values, the first is the Network Allocation Vector (NAV) (or alternately its incremental value ΔNAV), which specifies a period value P3 for the intra-cell contention-free period for member stations in its own cell. Member stations within the cell 150 must wait for the period P3 before beginning the Tiered Contention Multiple Access (TCMA) procedure, as shown in FIG. 1K . The other contention-free period value included in the beacon packet 124 is the Inter-BSS Network Allocation Vector (IBNAV), which specifies the contention-free time response (CFTR) period P4. The contention-free time response (CFTR) period P4 gives notice to any other cell receiving the beacon packet, such as cell 100 , that the first cell 150 has seized the medium for the period of time represented by the value P4. [0074] The beacon packet 124 is received by the member stations 154 A (with a low QoS requirement 164 A) and 154 B (with a high QoS requirement 164 B) in the cell 150 during the period from T1 to T2. The member stations 154 A and 154 B store the value of ΔNAV=P3 and begin counting down that value during the contention free period of the cell 150 . The duration of the intra-cell contention-free period ΔNAV=P3 is deterministically set. The member stations in the cell store the intra-cell contention-free period value P3 as the Network Allocation Vector (NAV). Each member station in the cell 150 decrements the value of the NAV in a manner similar to other backoff time values, during which it will delay accessing the medium. FIG. 1L shows the IEEE 802.11 packet structure 260 for the beacon packet 124 or 120 , including the increment to the NAV period and the CFTR period. The beacon packet structure 260 includes fields 261 to 267 . Field 267 specifies the ΔNAV value of P3 and the CFTR value of P4. In accordance with the invention, the method assigns to the first access point station, a first inter-cell contention-free period value, which gives notice to any other cell receiving the beacon packet, that the first cell has seized the medium for the period of time represented by the value. The inter-cell contention-free period value is deterministically set. [0075] Further in accordance with the invention, any station receiving the beacon packet 124 immediately rebroadcasts a contention-free time response (CFTR) packet 126 containing a copy of the first inter-cell contention-free period value P4. The value P4 specifies the Inter-BSS Network Allocation Vector (IBNAV), i.e., the contention-free time response (CFTR) period that the second access point 102 must wait, while the first cell 150 has seized the medium. FIG. 1B shows overlap station 106 in the region of overlap 170 transmitting the CFTR packet 126 to stations in both cells 100 and 150 during the period front T1 to T2. FIG. 1M shows the IEEE 802.11 packet structure 360 for a CFTR packet 126 or 122 , including the CFTR period. The CFTR packet structure 360 includes fields 361 to 367 . Field 367 specifies the CFTR value of P4. In this manner, the notice is distributed to the second access point station 102 in the overlapping, second cell 100 . [0076] FIG. 1C shows the point coordinator in access point 152 of cell 150 controlling the contention-free period within the cell 150 by using the polling packet 128 during the period from T2 to T3. In the mean time, the second access point 102 in the second cell 100 connected to backbone network 110 , stores the first inter-cell contention-free period value P4 received in the CFTR packet 126 , which it stores as the Inter-BSS Network Allocation Vector (IBNAV). The second access point 102 decrements the value of IBNAV in a manner similar to other backoff time values, during which it will delay accessing the medium. [0077] Still further in accordance with the invention, the method uses the Tiered Contention Multiple Access (TCMA) protocol to assign to first member stations in the first cell 150 , a first shorter backoff value for high Quality of Service (QoS) data and a first longer backoff value for lower QoS data. FIG. 1D shows the station 154 B in the cell 150 , having a high QoS requirement 164 B, decreasing its High QoS backoff period to zero and beginning TCMA contention to transmit its high QoS data packet 130 during the period from T3 to T4. The backoff time is the interval that a member station waits after the expiration of the contention-free period P3, before the member station 154 B contends for access to the medium. Since more than one member station in a cell may be competing for access, the actual backoff time for a particular station can be selected as one of several possible values. In one embodiment, the actual backoff time for each particular station is deterministically set, so as to reduce the length of idle periods. In another embodiment, the actual backoff time for each particular station is randomly drawn from a range of possible values between a to minimum delay interval to a maximum delay interval. The range of possible backoff time values is a contention window. The backoff values assigned to a cell may be in the form of a specified contention window. High QoS data is typically isochronous data such as streaming video or audio data that must arrive at its destination at regular intervals. Low QoS data is typically file transfer data and email, which can be delayed in its delivery and yet still be acceptable. The Tiered Contention Multiple Access (TCMA) protocol coordinates the transmission of packets within a cell, so as to give preference to high QoS data over low QoS data, to insure that the required quality of service is maintained for each type of data. [0078] The method similarly assigns to the second access point 102 station in the second wireless LAN cell 100 that overlaps the first sell 150 , a second contention-free period value CFTR=P7 longer than the first contention-free period value CFTR=P4. FIG. 1E shows the second access point 102 in the cell 100 transmitting its beacon packet 120 including its contention-free period values of NAV (P6) and IBNAV (P7), to the member stations 104 A (with a low QoS requirement 114 A), 104 B (with a high QoS requirement 114 B) and 106 in the cell 100 during the period from T4 to T5. FIG. 1F shows that each station, including the overlap station 106 , that receives the second beacon packet 120 , immediately responds by retransmitting a second contention-free time response (CFTR) packet 122 that contains a copy of the second inter-cell contention-free period value P7 during the period from T4 to T5. [0079] FIG. 1G shows the point coordinator in access point 102 of cell 100 controlling the contention-free period within cell 100 using the polling packet 132 during the period from T5 to T6. [0080] The method uses the Tiered Contention Multiple Access (TCMA) protocol to assign to second member stations in the second cell 100 , a second shorter backoff value for high QoS data and a second longer backoff value for lower QoS data. FIG. 1H shows the station 104 B in the cell 100 , having a high QoS requirement 114 B, decreasing its High QoS backoff period to zero and beginning TCMA contention to transmit its high QoS data packet 134 during the period from T6 to T7. FIG. 1I shows the first member stations 154 A and 154 B in the first cell 150 waiting for the countdown of their NAVs, to begin the TCMA protocol of counting down the first longer backoff for low QoS data and then transmitting first low QoS data 136 during the period from T7 to T8. FIG. 1J shows the second member stations 104 A, 104 B, and 106 are waiting for the TCMA protocol of counting down the second longer backoff for lower QoS data before transmitting the second lower QoS data 138 during the period from T8 to T9. [0081] The first and second cells are considered to be overlapped when one or more stations in the first cell can inadvertently receive packets from member stations or the access point of the other cell. The invention reduces the interference between the overlapped cells by coordinating the timing of their respective transmissions, while maintaining the TCMA protocol's preference for the transmission of high QoS data over low QoS data in each respective cell. [0082] During the operation of two overlapped cells, the method in FIG. 1A transmits a first beacon packet 124 including the intra-cell contention-free period value (the increment to the NAV) and inter-cell contention-free period value (the CFTR), from the first access point 152 to the first member stations 154 B and 154 A in the first cell 150 . The beacon packet is received by the member stations of the first cell and inadvertently by at least one overlapped member station 106 of the second cell 100 . Each member station 154 B and 154 A in the first cell increments its NAV with the intra-cell contention-free period value P3 and stores the inter-cell contention-free period value P4 as the CFTR. [0083] In accordance with the invention, each station that receives the first beacon packet 124 , immediately responds by transmitting a first contention-free time response (CFTR packet 126 in FIG. 1B that contains a copy of the inter-cell contention-free period P4 value (CFTR). A CFTR packet 126 is transmitted from the first member stations 154 B and 154 A in the first cell 150 and also by the overlapped member stations 106 of the second cell 100 . The effect of the transmission of CFTR packets 126 from member stations 106 in the second cell 100 is to alert the second access point 102 and the second member stations 104 A and 104 B in the second cell 100 , that the medium has been seized by the first access point 152 in the first cell 150 . When the second access point 102 in the second cell 100 receives the CFTR packet 126 it stores a copy of the inter-cell contention-free period value P4 as the IBNAV. [0084] Similar to a station's Network Allocation Vector (NAV), an IBNAV is set at the access point to indicate the time the medium will be free again. Also similar to the NAV, the IBNAV is decremented with each succeeding slot, similar to the decrementing of other backoff times. When the second access point receives a new IBNAV representing the first cell's contention-free period value, then the second access point must respect the IBNAV value and delay transmitting its beacon packet and the exchange of other packets in the second cell until the expiration of the received, IBNAV. [0085] Later, as shown in FIG. 1E , when the second access point 102 transmits its second beacon packet 120 including its second contention-free period values of NAV (P6) and IBNAV (P7), to the second member stations 104 A, 104 B and 106 in the second cell 100 , each station that receives the second beacon packet, immediately responds by transmitting a second contention-free time response (CFTR) packet 122 in FIG. 1F , that contains a copy of the second inter-cell contention-free period value P7. A CFTR packet 122 is transmitted from the second member stations 104 A, 104 B and overlapped station 106 in the second cell and also by the overlapped member stations of the first cell. The effect of the transmission of CFTR packets from overlapped member station 106 is to alert the first access point 152 and the first member stations 145 A and 154 B in the first cell 150 , that the medium has been seized by the second access point 102 in the second cell 100 . When the first access point 152 in the first cell 150 receives the CFTR packet 122 it stores the a copy of the second inter-cell contention-free period value P7 as an IBNAV, to indicate the time the medium will be free again. The IBNAV is decremented with each succeeding slot, similar to the decrementing of other backoff times. [0086] The second member stations 104 A, 104 B, and 106 in the second cell 100 wait for completion of the countdown of their NAVs to begin the TCMA protocol of counting down the second shorter backoff for high QoS data and then transmitting second high QoS data packets, as shown in FIGS. 1G and 1H . [0087] Meanwhile, the first access point 152 in the first cell 150 waits for completion of the countdown of the second inter-cell contention-free period P7 in its IBNAV in FIGS. 1G and 1H before starting the countdown of its own NAV for its own intra-cell contention-free period. The first member stations 154 A and 154 B in the first cell 150 wait for the countdown of their NAVs, to begin the TCMA protocol of counting down the first longer backoff for low QoS data and then transmitting first low QoS data in FIG. 1I . [0088] Meanwhile the second member stations 104 A, 104 B, and 106 are waiting for the TCMA protocol of counting down the second longer backoff for lower QoS data before transmitting the second lower QoS data 138 in FIG. 1J . [0089] In this manner, interference in a medium between overlapping wireless LAN cells is reduced. DETAILED DESCRIPTION OF THE INVENTION [0090] TCMA can accommodate co-existing Extended Distributed Coordination Function (E-DCF) and centralized access protocols. In order to ensure that the centralized access protocol operating under Hybrid Coordination Function (HCF) is assigned top priority access, it must have the shortest arbitration time. Its arbitration time is determined by considering two additional requirements: uninterrupted control of the channel for the duration of the contention-free period, and backward compatibility. Uninterrupted Contention-Free Channel Control [0091] The channel must remain under the control of the centralized access protocol until the contention-free period is complete once it has been seized by the centralized access protocol. For this, it is sufficient that the maximum spacing between consecutive transmissions exchanged in the centralized access protocol, referred to as the central coordination time (CCT), be shorter than the time the channel must be idle before a station attempts a contention-based transmission following the end of a busy-channel time interval. The centralized access protocol has a CCT equal to the Priority Interframe Space (PIFS). Hence, no station may access the channel by contention, using either the distributed coordination function (DCF) or Extended-DCF (E-DCF) access procedure, before an idle period of length of the DCF Interframe Space (DIFS) equaling PIFS+1(slot time) following the end of a busy-channel time interval. This requirement is met by DCF. For E-DCF, it would be sufficient for the Urgency Arbitration Time (UAT) of a class j, UAL to be greater than PIFS for all classes j>1. Backward Compatibility [0092] Backward compatibility relates to the priority treatment of traffic handled by enhanced stations (ESTAs) as compared to legacy stations (STAs). In addition to traffic class differentiation, the ESTAs must provide certain traffic classes with higher or equal priority access than that provided by the STAs. That means that certain traffic classes should be assigned a shorter arbitration times than DIFS, the de facto arbitration time of legacy stations. [0093] Because the time in which the “clear channel assessment” (CCA) function can be completed is set at the minimum attainable for the IEEE 802.11 physical layer (PHY) specification, the arbitration times of any two classes of different priority would have to be separated by at least one “time slot”. This requirement implies that the highest priority traffic class would be required to have an arbitration time equal to DIFS−1(slot time)=PIFS. [0094] Though an arbitration time of PIFS appears to fail meeting the requirement for uninterrupted control of the channel during the contention-free period, it is possible for an ESTA to access the channel by E-DCF using an arbitration time of PIFS and, of the same time, allow priority access to the centralized access protocol at PIFS. This is achieved as follows. Contention-based transmission is restricted to occur after a DIFS idle period following the end of a busy channel period by ensuring that the backoff value of such stations is drawn from a random distribution with lower bound that is at least 1. Given that all backlogged stations resume backoff countdown after a busy-channel interval with a residual backoff of at least 1, an ESTA will attempt transmission following completion of the busy interval only after an idle period equal to PIFS+1(slot time)=DIFS. This enables the centralized access protocol to maintain control of the channel without colliding with contention-based transmissions by ESTAs attempting to access the channel using E-DCF. [0095] To see that the residual backoff value of a backlogged station will be greater than or equal to 1 whenever countdown is resumed at the end of a busy channel period, consider a station with a backoff value m>0. The station will decrease its residual backoff value by 1 following each time slot during which the channel remains idle. If m reaches 0 before countdown is interrupted by a transmission, the station will attempt transmission. The transmission will either fail, leading to a new backoff being drawn, or succeed. Therefore, countdown will be resumed after the busy-channel period ends, only with a residual backoff of 1 or greater. Consequently, if the smallest random backoff that can be drawn is 1 or greater, an ESTA will always wait for at least a DIFS idle interval following a busy period before it attempts transmission. [0096] Only one class can be derived with priority above legacy through differentiation by arbitration time alone, by using the arbitration time of PIFS. Multiple classes with that priority can be obtained by differentiation through other parameters, such as the parameters of the backoff time distribution; e.g. the contention window size. For all the classes so derived, a DIFS idle period will follow a busy channel interval before the ESTA seizes the channel if the restriction is imposed that the backoff value of such stations be drawn from a random distribution with lower bound of at least 1. [0097] Because PIFS is shorter than DIFS, the traffic classes with arbitration time equal to PIFS will have higher access priority than the traffic classes with arbitration time equal to DIFS. As seen in FIG. 1 , which depicts the tiered contention mechanism, a station cannot engage in backoff countdown until the completion of an idle period of length equal to its arbitration time. Therefore, a legacy station will be unable to resume backoff countdown at the end of a busy-channel interval, if an ESTA with arbitration time of PIFS has a residual backoff of 1. Moreover, a legacy station will be unable to transmit until all higher-priority ESTAs with residual backoff of 1 have transmitted. Only legacy stations that draw a backoff value of 0 will transmit after a DIFS idle period, thus competing for the channel with the higher priority stations. This occurs only with a probability less than 3 percent, since the probability of drawing a random backoff of 0 from the range [0, 31] is equal to 1/32. Top Priority for the Centralized Access Protocol [0098] For the centralized access protocol to enjoy the highest priority access, it must have an arbitration time shorter than PIFS by at least a time slot; that is, its arbitration time must equal PIFS−1(slot time)=the Short Interframe Space (SIFS). As in the case of the highest traffic priority classes for ESTAs accessing the channel by E-DCF, the random backoff values for the beacon of the centralized access protocol must be drawn from a range with a lower bound of at least 1. Using the same reasoning as above, the centralized access protocol will not transmit before an idle period less than PIFS=SIFS+1(slot time), thus respecting the inter-frame spacing requirement for a SIFS idle period within frame exchange sequences. Consequently, the shorter arbitration time assigned to the centralized access protocol ensures that it accesses the channel with higher priority than any station attempting, contention-based access through E-DCF, while at the same time respecting the SITS spacing requirement. [0099] It should be noted that while collisions are prevented between frame exchanges during the contention-free period, collisions are possible both between the beacons of centralized access protocols of different BSSs located within interfering range [having coverage overlap], and between the beacon of a centralized access protocol and stations accessing the channel by contention using E-DCF. The probability of such collisions is low because higher priority nodes with residual backoff value m equal to 1 always seize the channel before lower priority nodes. Inter-access point collisions are resolved through the backoff procedure of TCMA. Inter-Access Point Contention [0100] Potential collisions between BSSs engaged in centralized access can be averted or resolved by a backoff procedure. The complication arising here is that a random backoff delay could result in idle periods longer periods than the SIFS+1(slot time)=PIFS, which is what ensures priority access to the centralized protocol over E-DCF traffic contention-based traffic. Hence, the collisions with contention-based traffic would occur. Using short backoff windows in order to avoid this problem would increase the collisions experienced. In accordance with the invention, deterministically set backoff delays are used, which tend to reduce the length of the idle periods. [0101] Another aspect of inter-BSS interference that affects the performance of centralized protocols adversely is the possible interruption with a collision of what starts as an interference-free poll/response exchange between the access point and its associated stations. The possibility of coincident or overlapping contention-free periods between neighboring BSSs is eliminated through the use of an “interference sensing” method employing a new frame. Deterministic Backoff Procedure for the Centralized Access Protocol [0102] A modified backoff procedure is pursued for the beacons of the centralized access protocols. A backoff counter is employed in the same way as in TCMA. But while the backoff delay in TCMA is selected randomly from a contention window, in the case of the centralized access protocol beacons, the backoff value is set deterministically. [0103] Scheduling of packet transmission occurs once per frame, at the beginning of the frame. Only the packets queued at the start of a frame will be transmitted in that frame. It is assumed that BSSs are synchronized. A means for achieving such synchronization is through the exchange of messages relayed by boundary stations [stations in the overlapping regions of neighboring BSSs]. [0104] The backoff delay is selected through a mechanism called “tag scheduling”. Tags, which are ordinal labels, are assigned to different BSSs. BSSs that do not interfere with one another may be assigned the same tag, while BSSs with the potential to interfere with one another must receive different tags. For each frame, the tags are ordered in a way that is known a priori. This order represents the sequence in which the BSS with a given tag will access the channel in that frame. The backoff delay increases with the rank of the “tag” that has been assigned to the BSS for the current frame, as tags are permuted to give each group of BSS with the same tag a fair chance at the channel. For instance, a cyclic permutation for three tags, t=1, 2, 3, would give the following ordering: 1, 2, 3 for the first frame, 3, 1, 2 next, and then 2, 3, 1. One could also use other permutation mechanisms that are adaptive to traffic conditions and traffic priorities. The difference in the backoff delays corresponding to two consecutive tags is one time slot. FIG. 2 illustrates the ordering of transmissions from three groups of BSSs. [0105] A backoff counter is associated with each backoff delay. It is decreased according to the rules of TCMA using the arbitration time of Short Interframe Space (SIFS) as described in the preceding section. That is, once the channel is idle for a time interval equal to SIFS, the backoff counter associated with the centralized protocol of the BSS is decreased by 1 for each slot time the channel is idle. Access attempt occurs when the backoff counter expires. The minimum backoff counter associated with the highest-ranking tag is 1. FIG. 3 illustrates how three interfering BSSs share the same channel for two consecutive frames. The tags assigned in each of the two frames are (1, 2), (2, 3), and (3, 1) for the three BSSs, respectively. The backoff delays for the three tags are 1, 2, and 3 time slots. [0106] When the channel is seized by the centralized protocol of a BSS, it engages in the polling and transmission functions for a time interval, known as the contention-free period. Once the channel has been successfully accessed that way, protection by the Network Allocation Vector (NAV) prevents interference from contention based traffic originating within that BSS. Avoidance of interference from neighboring BSS is discussed below. A maximum limit is imposed on the reservation length in order to even out the load on the channel from different BSSs and allow sufficient channel time for contention-based traffic. [0107] It is important to note the advantage of using deterministic backoff delays, versus random. Assuming an efficient (i.e., compact) tag re-use plan, deterministic backoff delays increase the likelihood that a beacon will occur precisely after an idle period of length SIFS+1=PIFS. This will enable the centralized protocol to gain access to the channel, as a higher priority class should, before contention-based traffic can access the channel at DIFS=PIFS+1. Using a random backoff delay instead might impose a longer idle period and hence, give rise to collisions with contention-based traffic. Use of short backoff windows to avoid this problem would be ill advised, since that would result in collision between the various BSS beacons. [0108] Though the backoff delays are set in a deterministic manner, there are no guarantees that collisions will always be avoided. Unless the duration of the contention-free period is the same for all BSSs, there is the possibility that interfering BSSs will attempt to access the channel at once. In case of such a collision, the backoff procedure starts again with the backoff delay associated with the tag assigned to the BSS, decreased by 1, and can be repeated until expiration of the frame. At the start of a new frame, a new tag is assigned to the BSS according to the pre-specified sequence, and the deferral time interval associated with the new tag is used. [0109] Collisions are also possible if tag assignments are imperfect (interfering BSSs are assigned the same tag). In the event of such a collision, transmission should be retried with random backoff. In order to deal with either type of collision, resolution occurs by drawing a random delay from a contention window size that increases with the deterministic backoff delay associated with the tag in that frame. Though random backoff is used in this event, starting with deterministic backoff helps reduce contention time. [0110] In a hybrid scenario, random backoff can be combined with tag scheduling. Instead of using backoff delays linked to the rank of a tag in a frame, the contention window size from which the backoff delay is drawn would increase with decreasing rank. The advantage of such an approach is to relax the restrictions on re-use by allowing the possibility that potentially interfering stations will be assigned the same tag. The disadvantage is that the Inter-BSS Contention Period (MCP) time needed to eliminate contention by E-DCF traffic increases. Interference Sensing [0111] Interference sensing is the mechanism by which the occupancy status of a channel is determined. The access point only needs to know of channel activity in interfering BSSs. The best interference sensing mechanism is one that ensures that the channel is not used simultaneously by potentially interfering users. This involves listening to the channel by both the access point and stations. If the access point atone checks whether the channel is idle, the result does not convey adequate information on the potential for interference at a receiving station, nor does it address the problem of interference caused to others by the transmission, as an access point may not be able to hear transmissions from its neighboring access points, yet there is potential of interference to stations on the boundary of neighboring BSSs. Stations must detect neighboring BSS beacons and forward the information to their associated access point. However, transmission of this information by a station would cause interference within the neighboring BSS. [0112] In order to enable communication of channel occupancy information to neighboring access points, the invention includes the following mechanism. When a beacon packet is transmitted, and before transmission of any other data or polling packets, all stations hearing the beacon will respond by sending a frame, the contention-free time response (CFTR), that will contain the duration of the contention-free period found in the beacon. An access point in neighboring BSSs, or stations attempting contention-based channel access, that receive this message from a station in the BSS overlapping region are thus alerted that the channel has been seized by a BSS. Similar to a station's Network Allocation Vector (NAV), an Inter-Cell Network Allocation Vector, also referred to herein as an inter-BSS NAV (IBNAV), is set at the access point, accordingly, indicating the time the channel will be free again. Unless the IBNAV is reset, the access point will decrease its backoff value only after the expiration of the IBNAV, according to the backoff countdown rules. [0113] Alternatively, if beacons are sent at fixed time increments, receipt of the contention-free time response (CFTR) frame would suffice to extend the IBNAV. The alternative would be convenient in order to obviate the need for full decoding of the CFTR frame. It is necessary, however, that the frame type of CFTR be recognizable. [0114] Contention by E-DCF traffic white various interfering BSSs attempt to initiate their contention-free period can be lessened by adjusting the session length used to update the NAV and IBNAV. The contention-free period length is increased by a period Inter-BSS Contention Period (IBCP) during which the access points only will attempt access of the channel using the backoff procedure, while ESTAs wait for its expiration before attempting transmission. This mechanism can reduce the contention seen by the centralized protocols when employing either type of backoff delay, random or deterministic. With deterministic backoff delays, IBCP is set equal to the longest residual backoff delay possible, which is T(slot time), where T is the number of different tags. Given reasonable re-use of the tags, the channel time devoted to the IBCP would be less with deterministic backoff delays, as compared to the random. QoS Management [0115] A QoS-capable centralized protocol will have traffic with different time delay requirements queued in different priority buffers. Delay-sensitive traffic will be sent first, followed by traffic with lower priority. Tag scheduling is used again, but now there are two or more backoff values associated with each tag, a shorter value for the higher priority traffic and longer ones for lower priority. A BSS will transmit its top priority packets first, as described before. Once the top priority traffic has been transmitted, there would be further delay before the BSS would attempt to transmit lower priority traffic in order to give neighboring BSSs a chance to transmit their top priority packets. As long as any of the deferral rime intervals for low-priority traffic is longer than the deferral time intervals for higher priority traffic of any tag, in general all neighboring BSSs would have a chance to transmit all pending top-priority packets before any lower-priority packets are transmitted. [0116] FIG. 4 illustrates how three interfering BSSs, each with two types of traffic of different priorities, share the same channel in two consecutive frames. As before, the tags assigned in each of the two frames are (1, 2), (2, 3), and (3, 1) for the three BSSs, respectively. The deferral times for the top priority traffic are 1, 2, and 3 time slots for tags 1, 2, and 3, respectively. The deferral times for the higher priority traffic are 4, 5, and 6 time slots for tags 1, 2, and 3, respectively. Tag Assignments [0117] A requirement in assigning tags to BSS is that distinct tags must be given to user entities with potential to interfere. This is not a difficult requirement to meet. In the absence of any information, a different tag could be assigned to each user entity. In that case, non-interfering cells will use the channel simultaneously even though they have different tags. Interference sensing will enable reuse of the channel by non-interfering BSSs that have been assigned different tags. [0118] There are advantages, however, in reducing the number of different tags. For instance, if the interference relationships between user entities are known, it is advantageous to assign the same tag to non-interfering BSS, and thus have a smaller number of tags. The utilization of bandwidth, and hence total throughput, would be greater as shorter deferral time intervals leave more of the frame time available for transmission. Moreover, an efficient (i.e., compact) tag re-use plan will decrease the likelihood of contention between the centralized protocol beacons of interfering BSSs contenting for access and E-DCF traffic. This problem is mitigated by using the IBCP time in the IBNAV, but re-use will reduce the length of this time. [0119] The assignment of tags to cells can be done without knowledge of the location of the access points and/or the stations. Tag assignment, like channel selection can be done at the time of installation. And again, like dynamic channel selection, it can be selected by the access point dynamically. RF planning, which processes signal-strength measurements can establish re-use groups and thus reduce the required number of tags. FIG. 5 , which includes FIGS. 5( a ) and 5( b ) , illustrates the possible re-use of tags. In FIG. 5( a ) , the access points are located at ideal spots on a hexagonal grid to achieve a regular tessellating pattern. In FIG. 5( b ) , the access points have been placed as convenient and tags are assigned to avoid overlap. Imperfect tag assignments will lead to collisions between the access points, but such collisions can be resolved. [0120] To recap, arbitration times have been assigned to a centralized access protocol that co-exists with ESTAs accessing the channel through E-DCF. The centralized access protocol has the top priority, while E-DCF can offer traffic classes with priority access both above and below that provided by legacy stations using DCF. [0121] Table 1 illustrates the parameter specification for K+1 different classes according to the requirements given above. The centralized access protocol is assigned the highest priority classification, and hence the shortest arbitration time. The top k−1 traffic classes for the E-DCF have priority above legacy but below the centralized access protocol; they achieve differentiation through the variation of the contention window size as well as other parameters. E-DCF traffic classes with priority above legacy have a lower bound, rLower, of the distribution from which backoff values are drawn that is equal to 1 or greater. Differentiation for classes with priority below legacy is achieved by increasing arbitration times; the lower bound of the random backoff distribution can be 0. [0122] BSSs within interfering range of one another compete for the channel through a deterministic backoff procedure employing tag scheduling, which rotates the backoff value for fairness among potentially interfering BSS. Re-use of a tag is permitted in non-interfering BSS. Multiple queues with their own backoff values enable prioritization of different QoS traffic classes. Contention-Free Bursts [0123] In accordance with the invention, potential collisions between different BSSs engaged in centralized access can be averted/resolved by deterministic backoff delays, which avoid collisions between access points, and eliminate gaps between consecutive poll/response exchanges between the access point and its associated stations. These are referred to as contention-free bursts (CFBs). Deterministic Backoff Procedure for the Centralized Access Protocol [0124] A modified backoff procedure is pursued for the beacons of the centralized access protocols. A backoff counter is employed in the same way as in TCMA. But while the backoff delay in TCMA is selected randomly from a contention window, in the case of the centralized access protocol beacons, the backoff value is set deterministically to a fixed value Bkoff, at the end of its contention-free session. Post-backoff is turned on. [0125] The backoff counter is decreased according to the rules of TCMA using the arbitration time AIFS=SIFS as described in the preceding section. That is, once the channel is idle for a time interval equal to SIFS, the backoff counter associated with the centralized protocol of the BSS is decreased by 1 for each slot time the channel is idle. Access attempt occurs when the backoff counter expires. An HC will restart its backoff after completing its transmission. The deterministic post-backoff procedure is illustrated in FIG. 6 . [0126] When the channel is seized by the centralized protocol of a BSS, it engages in the polling and transmission functions for a time interval, known as the contention-free period. Once the channel has been successfully accessed that way, protection by the NAV prevents interference from contention based traffic originating in the BSS. Avoidance of interference from neighboring BSS is discussed below. Non-Conflicting Contiguous Sequences of CFBs [0127] As long as the value of Bkoff is greater than or equal to the maximum number of interfering BSS, it is possible for the contention-free periods of a cluster of neighboring/overlapping BSSs to repeat in the same order without a collision between them. CFBs of different BSSs can be made to follow one another in a contiguous sequence, thus maximizing access of the centralized protocol to the channel. This can be seen as follows. [0128] Given a sequence of successful CFBs initiated by different BSSs, subsequent CFBs will not conflict because the follower's backoff counter always exceeds that of the leader by at least 1. If the previous CFBs were contiguous (that is, if consecutive CFBs were separated by idle gaps of length PIFS, the new CFBs will be also continuous because the follower's backoff delay exceeds that of the leader by exactly 1. Channel access attempts by E-DCF stations require an idle gap of length equal to DIFS or greater. FIG. 7 shows the relationships of repeating sequences of CFBs. [0129] In order to maintain contiguity, an HC that does not have any traffic to transmit when its backoff expires, it will transmit a short packet—a “peg”—and then engage in post-backoff. This way no gaps of length DIFS+1 are left idle until all HCs have completed one CFB per cycle, and restarted the backoff countdown procedure. E-DCF stations are thus prevented from seizing the channel until each BSS completes at least one CFB per cycle. FIG. 8 illustrates the role of pegging in a sequence of CFBs by three overlapping access points. [0130] Finally it is shown how such a contiguous sequence can constructed by analyzing how a new access point initiates its first CFB. Every time a new access point is installed, it must find its position in the repeating sequence of CFBs. The new access point listens to the channel for the desired cycle, trying to recognize the sequence. It listens for an “idle” PIFS following a busy channel. When that occurs, or after counting Bkoff time slots, whichever comes first, the new access point starts looking for the first idle longer than PIFS, which signifies the end of the sequence of CFBs. As long as the Bkoff is greater than the number of interfering BSS, there will always be such an idle period. The access point sets its post-backoff delay so that it transmits always right at the end of the CFB sequence. That is if at time t, an idle>PIFS has been detected, the access point's backoff at time t is Bkoff−x(t), where x(t) is the number of idle time slots after PIFS. FIG. 9 illustrates this start-up procedure for a new access point, HC2, given an existing access point, HC1. Interference Sensing [0131] Interference sensing is the mechanism by which the occupancy status of a channel is determined. The access point only needs to know of channel activity in interfering BSSs. The best interference sensing mechanism is one that ensures that the channel is not used simultaneously by potentially interfering users. This involves listening to the channel, by both the access point and stations. If the access point alone checks whether the channel is idle, the result does not convey adequate information on the potential for interference at a receiving station, nor does it address the problem of interference caused to others by the transmission, as an access point may not be able to hear transmissions from its neighboring access points, yet there is potential of interference to stations on the boundary of neighboring BSS. Stations must detect neighboring BSS beacons and forward the information to their associated access point. However, transmission of this information by a station would cause interference within the neighboring BSS. [0132] In order to enable communication of channel occupancy information to neighboring access points, the following mechanism is proposed. When a beacon packet is transmitted, and before transmission of any other data or polling packets, all stations not associated with the access point that hear the beacon will respond by sending a frame, the contention-free time response (CFTR), that will contain the duration of the contention-free period found in the beacon. An associated station will transmit the remaining duration of the contention-free period when polled. An access point in neighboring BSSs, or stations attempting contention-based channel access, that receive this message from a station in the BSS overlapping region are thus be alerted that the channel has been seized by a BSS. Similar to a station's NAV, an inter-BSS NAV (IBNAV) will be set at the access point accordingly indicating the time the channel will be free again. Unless the IBNAV is reset, the access point will decrease its backoff value only after the expiration of the IBNAV, according to the backoff countdown rules. [0133] Alternatively, if beacons are sent at fixed time increments, receipt of the CFTR frame would suffice to extend the IBNAV. The alternative would be convenient in order to obviate the need for full decoding of the CFTR frame. It is necessary, however, that the frame type of CFTR be recognizable. [0134] Contention by E-DCF traffic while various interfering BSSs attempt to initiate their contention-free period can be lessened by adjusting the session length used to update the NAV and IBNAV. The contention-free period length is increased by a period IBCP (inter-BSS contention period) during which the access points only will attempt access of the channel using the backoff procedure, while ESTAs wait for its expiration before attempting transmission. This mechanism can reduce the contention seen by the centralized protocols when employing either type of backoff delay—random or deterministic. QoS Management [0135] A QoS-capable centralized protocol will have traffic with different time delay requirements queued in different priority buffers. Delay-sensitive traffic will be sent first, followed by traffic with lower priority. A BSS will schedule transmissions from separate queues so that the QoS requirements are met. It will transmit its top priority packets first, as described before. Once the top priority traffic has been transmitted, the BSS would attempt to transmit lower priority traffic in the CFBs allotted. [0136] Three parameters are employed to help manage QoS. The deterministic backoff delay, Bkoff, and the maximum length of a CFB and of a DCF transmission. Since these parameters determine the relative allocation of the channel time between the centralized and distributed protocols, they can be adjusted to reflect the distribution of the traffic load between the two protocols. It must be kept in mind, however, that the same value of Bkoff should be used by all interfering BSSs. QoS Guarantees [0137] To enable high priority traffic to be delivered within guaranteed latency limits, a variation of the above method is described. CFBs of an access point are separated into two types, or tiers. The first contains time sensitive data and is sent when the period TXdt expires. The second tier contains time non-sensitive traffic and is sent when the backoff counter expires as a result of the countdown procedure. When all neighboring BSS have a chance to transmit their time sensitive traffic, the channel is available for additional transmissions before needing to transmit time-sensitive traffic again. Lower priority contention-free data can be then transmitted, using a backoff-based procedure. [0138] Tier II CFBs can be initiated in various methods. Two will be described here. They are: (1) random post-backoff, and (2) deterministic post-backoff. Both methods use the same AIFS used for top-priority EDCF transmissions, in order to avoid conflict with Tier I CFBs (i.e. an AIFS=PIFS). Conflict with top priority EDCF transmissions can be mitigated in case (1) or prevented in case (2) through the use of the IBNAV with an IBCP. [0139] Random post-backoff assigns an access point a backoff drawn from a prespecified contention window. A short contention window would lead to conflicts between Tier II CFBs. A long contention window reduces the conflict between interfering BSS attempting to access the channel at once. Long backoff values would reduce the fraction of the time the channel carries CFBs. Furthermore, the gaps created by multiple consecutive idle slots make room for DCF transmissions, reducing further the channel time available to CFBs. A long IBCP value would alleviate some of the conflict with DCF transmissions. [0140] Deterministic post-backoff eliminates the problems present with random post-backoff. Conflicts with top priority EDCF transmissions can be prevented with an IBCP of 1. Moreover, as explained above, the Tier II CFBs generated by this method, do not conflict with one another and form contiguous repeating sequences. Non-Conflicting Contiguous Sequences of Tier I CFBs [0141] Periodic transmission is achieved by maintaining a timer which is reset at the desired period TXdt as soon as the timer expires. A CFB is initiated upon expiration of the timer. As long as Tier I contention-free periods are all made the same size (by adding time non-critical traffic), which is not less than the maximum DCF transmission or Tier II CFB length, it is possible for the contention-free periods of a cluster of neighboring/overlapping BSSs to repeat in the same order without a collision between them. CFBs of different BSSs can be made to follow one another in a contiguous sequence, thus maximizing access of the centralized protocol to the channel. This can be seen as follows. [0142] Given a sequence of successful CFBs initiated by different BSSs, subsequent CFBs will not conflict because their timers will expire at least TICFBLength apart. If the leading access point's timer expires while the channel is busy, it will be able to start a new CFB before the follower HC because DCF transmissions are of equal or shorter length, and Type II CFBs have equal or shorter length. [0143] If the previous CFBs were contiguous (that is, if consecutive CFBs were separated by idle gaps of length PIFS), the new CFBs will be also continuous because the follower's timer will expire on or before the completion of the leader's CFB because their CFBs have the same length. Channel access attempts by E-DCF stations or Tier II CFBs require an idle gap of length equal to DIPS or greater, and hence they cannot be interjected. FIG. 10 shows the relationship of repeating sequences of Tier I CFBs. [0144] Finally it is shown how such a contiguous sequence can constructed by analyzing how a new access point initiates its first Tier I CFB. Every time a new access point is installed, it musts find its position in the repeating sequence of CFBs. The new access point listens to the channel for the desired cycle, trying to recognize the sequence. It listens for an “idle” PIFS following a busy channel. When that occurs, or after a period TXdt, whichever comes first, the new access, point starts looking for the first idle longer than PIFS, which signifies the end of the sequence of Tier I CFBs. As long as the TXdt is greater than the number of interfering BSS times the duration of a Tier I CFB, TICFBLength, there will always be such an idle period. The access point sets its timer so that it transmits always right at the end of the CFB sequence. That is, if at time t, an idle of length X(t)>PIFS has been detected, the access point's timer at time t is TXdt−X(t)+PIFS. FIG. 11 illustrates this start-up procedure for a new access point, HC2, given an existing access point, HC1. Possibility of Collisions [0145] Though the backoff delays are set in a deterministic manner, there are no guarantees that collisions will always be avoided. Unless all access points sense the start and end of CFBs at the same time, there is the possibility that interfering BSSs will attempt to access the channel at once. This situation arises when there is significant distance between access points, but not sufficient to eliminate interference between them. Such a situation can be alleviated through the assignment for different channels. [0146] Arbitration times are assigned to a centralized access protocol that co-exists with ESTAs accessing the channel through E-DCF. The centralized access protocol has the top priority, while E-DCF can offer traffic classes with priority access both above and below that provided by legacy stations using DCF. [0147] Table 1 illustrates the parameter specification for K+1 different classes according to the requirements given above. The centralized access protocol is assigned the highest priority classification, and hence the shortest arbitration time The top k−1 traffic classes for the E-DCF have priority above legacy but below the centralized access protocol; they achieve differentiation through the variation of the contention window size as well as other parameters. E-DCF traffic classes with priority above legacy have a lower bound, rLower, of the distribution from which backoff values are drawn that is equal to 1 or greater. Differentiation for classes with priority below legacy is achieved by increasing arbitration times; the lower bound of the random backoff distribution can be 0. [0000] TABLE 1 TCMA Priority Class Description Priority Description Arbitration time rLower 0 Centralized access protocol SIFS >=1 I to k − I E-DCF Traffic with priority PIFS = SIFS + 1 (slot time) >=1 Legacy or Centralized access Tier II CFBs k E-DCF Legacy-equivalent traffic DIFS = SIFS + 2 (slot time) 0 priority N = k + I to K E-DCF Traffic priority below >DIFS = SIFS + (2 + n − k) 0 Legacy (slot time) [0148] BSSs within short interfering range of one another can compete for and share the channel through the use of a deterministic backoff procedure employing post-backoff. Contiguous repeating sequences of contention-free periods provide the centralized protocol efficient access to the channel which is shared by E-DCF transmissions. The relative channel time allotted to the two protocols can be adjusted by tuning parameters of the protocol. Scheduling of traffic queued in multiple queues at the access point can meet QoS requirements. More stringent latency requirements can be met with a two-tiered method, which employs both a timer and post-backoff to initiate CFBs. [0149] CFB contiguity is preserved when using deterministic post-backoff or if CFBs of constant length are used whenever transmission is caused by the expiration of the TXdt timer—the Tier I approach. Contiguity is not necessarily preserved, however, if to the CFBs have variable length when the Tier I approach is used. Any gaps that would arise in this case would allow contention-based transmissions to be interjected, thus risking delays and possible collisions between HCs. [0150] Because of the fixed CFB length requirement, whereas the Tier I approach delivers regularly-spaced CFBs, using it alone, without a Tier II protocol, results in inefficient utilization of the channel. The same fixed bandwidth allocation to each BSS gives rise to situations where channel time allocated for a CFB to one BSS may be left idle while another BSS is overloaded. The Tier II protocols provide for dynamic bandwidth allocation among BSSs. [0151] Various illustrative examples of the invention have been described in detail. In addition, however, many modifications and changes can be made to these examples without departing from the nature and spirit of the invention.

A method and system reduce interference between overlapping first and second wireless LAN cells in a medium. Each cell includes a respective plurality of member stations and there is at least one overlapped station occupying both cells. An inter-cell contention-free period value is assigned to a first access point station in the first cell, associated with an accessing order in the medium for member stations in the first and second cells. The access point transmits a beacon packet containing the inter-cell contention-free period value, which is intercepted at the overlapped station. The overlapped station forwards the inter-cell contention-free period value to member stations in the second cell. A second access point in the second cell can then delay transmissions by member stations in the second cell until after the inter-cell contention-free period expires.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Divisional of U.S. Ser. No. 10/628,868, filed on Jul. 28, 2003, now U.S. Pat. No. 6,943,054 which claims priority to and benefit of U.S. Ser. No 60/489,992, filed on Jul. 25, 2003, both of which are incorporated herein by reference in their entirety for all purposes. STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT This invention was made with Government support under Grant No. MDA972-01-C-0072 awarded by the Army. The Government has certain rights in this invention. FIELD OF THE INVENTION This invention pertains to the field of semiconductor fabrication. In particular this invention provides novel methods of coupling organic molecules to group III, IV, and V elements (e.g., silicon, germanium, etc.), and the like. BACKGROUND OF THE INVENTION The fabrication of ordered molecular assemblies on conducting silicon surfaces is of considerable interest owing to its potential applications in the microelectronic industry. One goal of semiconductor fabrication is to increase the density of active elements provided on an integrated circuit. In order to accomplish this, efforts have turned to the use of self-assembling molecular structures as an alternative to, or in conjunction with various lithographic processes to form the active elements used in integrated circuits. In addition, interest has turned to the use of organic molecules to form such active elements (e.g., memory elements) (see, e.g., U.S. Pat. Nos. 6,272,038, 6,212,093, and 6,208,553, and PCT Publication WO 01/03126) and/or to form components of certain devices (e.g., field effect transistors, gates, sensors, transducers, etc.). Organic molecules covalently attached to silicon are very stable due to the strength of Si—O and Si—C bonds. A number of approaches exist to form a covalent link between silicon and organic molecules (Buriak and Allen (1998) J. Am. Chem. Soc., 120: 1339–1340; Bansal and Lewis (1998) J. Phys. Chem. 102: 1067–1070; Zhu et al. (1999) Langmuir 15: 8147–8154; Coulter et al. (2000) J. Vac. Sci. Technol. A 18: 1965–1970; Bourkherroub and Wayner (1999) J. Am. Chem. Soc. 121: 11513–11515; Cleland et al. (1995) Faraday Commun., 91: 4001–4003; Bateman et al. (1998) Angew. Chem. Int. Ed., 37: 2683–2685). These approaches include chemical, electrochemical and vapor deposition on a hydrogen-terminated silicon surface. Such approaches, however, have typically involved difficult reaction conditions, have been relatively inefficient, have degraded the organic molecule(s), and/or have resulted in the production of fairly toxic materials. SUMMARY OF THE INVENTION This Invention provides a new procedure for attaching molecules to semiconductor surfaces, in particular silicon. The molecules include porphyrins and ferrocenes, which have been previously shown to be attractive candidates for molecular-based information storage. The new attachment procedure is simple, can be completed in short times, requires minimal amounts of material, is compatible with diverse molecular functional groups, and in some instances affords unprecedented attachment motifs. These features greatly enhance the integration of the molecular materials into the processing steps that are needed to create hybrid molecular/semiconductor information storage devices. Thus, in one embodiment, this invention provides a method of covalently coupling an organic molecule to a surface of a Group II, III, IV, V, or VI element or to a semiconductor comprising a Group II, III, IV, V, or VI element (more preferably to a material comprising a Group III, IV, or V element., most preferably to a material comprising a Group IV element). The method typically involves providing a heat resistant organic molecule derivatized with an attachment group (or a linker bearing an attachment group); and contacting the derivatized heat resistant organic molecule with a surface of the Group II, III, IV, V, or VI element or semiconductor comprising the Group II, III, IV, V, or VI element; and heating the surface to a temperature of at least about 200° C., more preferably to a temperature of at least about 300° C., whereby said attachment group forms a covalent bond with the surface. In certain embodiments, the surface is heated to a temperature of at least about 400° C. In certain embodiments, the heat-resistant organic molecule is a redox-active molecule (e.g., a porphyrin, a porphyrinic macrocycle, an expanded porphyrin, a contracted porphyrin, a linear porphyrin polymer, a porphyrinic sandwich coordination complex, a porphyrin array, etc.). In certain embodiments, the organic molecule comprises a porphyrinic macrocycle substituted at a β-position or at a meso-position. In certain embodiments, the organic molecule comprises a porphyrinic macrocycle containing at least two porphyrins of equal energies held apart from each other at a spacing less than about 50 Å such that the molecule has an even or odd hole oxidation state. In the latter state, the hole hops between the porphyrins. The odd hole oxidation state is different from and distinguishable from another oxidation state of the porphyrinic macrocycle. A variety of attachment groups can be used including, but not limited to 4-(hydroxymethyl)phenyl, 4-(S-acetylthiomethyl)phenyl, 4-(Se-acetylselenomethyl)phenyl, 4-(mercaptomethyl)phenyl, 4-(hydroselenomethyl)phenyl, 4-formylphenyl, 4-(bromomethyl)phenyl, 4-vinylphenyl, 4-ethynylphenyl, 4-allylphenyl, 4-[2-(trimethylsilyl)ethynyl]phenyl, 4-[2-(triisopropylsilyl)ethynyl]phenyl, 4-bromophenyl, 4-iodophenyl, 4-hydroxyphenyl, 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl bromo, iodo, hydroxymethyl, S-acetylthiomethyl, Se-acetylselenomethyl, mercaptomethyl, hydroselenomethyl, formyl, bromomethyl, chloromethyl, ethynyl, vinyl, allyl, 4-[2-(4-(hydroxymethyl)phenyl)ethynyl]phenyl, 4-(ethynyl)biphen-4′-yl, 4-[2-(triisopropylsilyl)ethynyl]biphen-4′-yl, 3,5-diethynylphenyl, 2-bromoethyl, and the like. The organic molecule derivatized with the attachment group can include, but is not limited to 5-[4-(S-acetylthiomethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-[4-(mercaptomethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-[4-(hydroxymethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-[4-(hydroxymethyl)phenyl]-10,15,20-tri-p-tolylporphinatozinc(II), 5-(4-allylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-formylphenyl)-15-phenyl-10,20-di-p-tolylporphinatozinc(II), 5-(4-bromomethylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-ethynylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-iodophenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-bromophenyl)-10,15,20-tri-p-tolylporphinatozinc(II), 5-(4-hydroxyphenyl)-10,15,20-trimesitylporphinatozinc(II), 5,10-bis(4-ethynylphenyl)-15,20-dimesitylporphinatozinc(II), 5-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5-iodo-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5,10-bis(4-iodophenyl)-15,20-dimesitylporphinatozinc(II), 5-[4-(2-trimethylsilyl)ethynyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5,15-bis(4-ethynylphenyl)-10,20-dimesitylporphinatozinc(II), 5,15-bis(4-iodophenyl)-10,20-dimesitylporphinatozinc(II), 5,10,15-tris(4-ethynylphenyl)-20-mesitylporphinatozinc(II), 5,15-bis(4-ethynylphenyl)-10,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5,15-bis(4-ethynylphenyl)porphinatozinc(II), 5,15-bis(3-ethynylphenyl)-10,20-dimesitylporphinatozinc(II), 5,10,15,20-tetrakis(4-ethynylphenyl)porphinatozinc(II), 5,10-bis[4-(2-(trimethylsilyl)ethynyl)phenyl]-15,20-dimesitylporphinatozinc(II), 5-(3,5-diethynylphenyl)-10,15,20-trimesitylporphinatozinc(II), 3,7-dibromo-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5-[4-(2-(trimethylsilyl)ethynyl)phenyl]-10,15,20-tri-p-tolylporphinatozinc(II), 5-[4-(Se-acetylselenomethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-(4-iodophenyl)-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5,10-bis(4-ethynylphenyl)-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5,10-bis(4-ethynylbiphen-4′-yl)-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5-(4-vinylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-vinylphenyl)-10,15,20-tri-p-tolylporphinatozinc(II), 5-(hydroxymethyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-allylphenyl)-10,15,20-tri-p-tolylporphinatozinc(II), 5-(4-allylphenyl)-10,15,20-tri-p-tolylporphinatocopper(II), type c triple decker [(tert-butyl) 4 phthalocyaninato]Eu[(tert-butyl) 4 phthalocyaninato]Eu[5,15-bis(4-ethynylphenyl)-10,20-bis(4-tert-butylphenyl)porphyrin], type c triple decker [(tert-butyl) 4 phthalocyaninato]Eu[(tert-butyl) 4 phthaloxyaninato]Eu[5-[4-[2-(4-(hydroxymethyl)phenyl)ethynyl]phenyl]-10,15,20-tri-p-tolylporphyrin]5,10-bis[4-(2-(triisopropylsilyl)ethynyl)biphen-4′-yl]-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5,10-bis[4-(2-(triisopropylsily)ethynyl)phenyl]-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), and the like. In certain embodiments, the Group III, IV, or V element is a Group IV element or a doped Group IV element (e.g., silicon, germanium, p- or n-doped silicon, p- or n-doped germanium, etc.). The surface can be a hydrogen passivated surface. In certain embodiments, the contacting comprises selectively applying the organic molecule to certain regions of said surface and not to other regions. The coating step can comprise placing a protective coating on the surface in regions where the organic molecule is not to be attached; contacting the solution with the surface; and removing the protective coating to provide regions of the surface without the organic molecule. The contacting can comprise contact printing of a solution comprising the organic molecule onto said surface. The contacting can comprise inkjet printing a solution comprising the organic molecule onto the surface. The contacting can comprise spraying or dropping a solution comprising the organic molecule onto the surface. The contacting can comprise dipping or coating the surface with a solution comprising the organic molecule and, optionally, etching regions of the surface to remove the organic molecule. In another embodiment, this invention provides a surface of a Group II, III, IV, V, or VI element or a surface of a semiconductor comprising a Group II, III, IV, V, or VI element having an organic molecule coupled thereto through a covalent bond, where the organic molecule is coupled to said surface by methods described herein. In certain embodiments, the organic molecule is a redox-active molecule and includes, but is not limited to any of the molecules described herein. Similarly the attachment groups include, but are not limited to any of the attachment groups described herein. In certain embodiments, the Group II, III, IV, V, or VI element, more preferably a Group III, IV, or V, element, still more preferably a Group IV element or a doped Group IV element (e.g., silicon, germanium, doped silicon, doped germanium, etc.). In certain embodiments, the surface comprises a surface in a transistor and/or a surface in a memory element. This invention also provides a redox-active substrate comprising a Group II, III, IV, V, or VI material having attached thereto a redox-active molecule where the redox-active molecule is covalently attached to said surface through an attachment group; the redox-active molecule is an organic molecule stable at a temperature of at least about 200° C.; and the covalent attachment is not by a silane. In certain embodiments, the redox-active molecule is coupled to the surface through a linker comprising an atom of carbon, oxygen, sulfur, or selenium. In certain embodiments, the organic molecule and/or the attachment groups include, but are not limited to any of the organic molecules and/or attachment groups described herein. In certain embodiments, the Group III, IV, or V element is a Group IV element (e.g., silicon, germanium, etc.). In certain embodiments, the surface is a doped (e.g., p-doped, n-doped, etc.) germanium or silicon surface. In certain embodiments, the substrate comprises an electrochemical cell, and/or a plurality of memory elements, and/or one or more integrated circuit elements (e.g., a transistor, a diode, a logic gate, a rectifier, an optronic element, etc.). In certain embodiments, the redox-active molecule on the substrate is electrically coupled to a device that reads or sets the oxidation state of that molecule (e.g., a voltammetric device, an amperometric device, a potentiometric device, a coulometric device, impedance spectrometer, etc.). In certain embodiments, a redox-active molecule on the substrate is electrically coupled to a sinusoidal voltammeter. This invention also provides a method of fabricating an ordered molecular assembly. The method typically involves providing a solution comprising a heat resistant organic molecule derivatized with an attachment group; contacting the solution with a surface comprising a Group III, IV, or V element at a plurality of discrete locations on the surface; and heating the surface to a temperature of at least about 200° C. whereby the attachment groups form covalent bonds with the surface at the plurality of discrete locations. In certain embodiments, the surface is heated to a temperature of at least about 300° C., or 400° C. Also provided is a kit for coupling an organic molecule to the surface of a type II, III, IV, V, or VI material. The kit typically involves a container containing a heat resistant organic molecule derivatized with an attachment group. In certain embodiments, the kit optionally additionally includes instructional materials teaching coupling the organic molecule to the surface by heating the surface to a temperature of about 200° C. or more. Definitions The term “oxidation” refers to the loss of one or more electrons in an element, compound, or chemical substituent/subunit. In an oxidation reaction, electrons are lost by atoms of the element(s) involved in the reaction. The charge on these atoms must then become more positive. The electrons are lost from the species undergoing oxidation and so electrons appear as products in an oxidation reaction. An oxidation is taking place in the reaction Fe 2+ (aq)→Fe 3+ (aq)+e − because electrons are lost from the species being oxidized, Fe 2+ (aq), despite the apparent production of electrons as “free” entities in oxidation reactions. Conversely the term reduction refers to the gain of one or more electrons by an element, compound, or chemical substituent/subunit. An “oxidation state” refers to the electrically neutral state or to the state produced by the gain or loss of electrons to an element, compound, or chemical substituent/subunit. In a preferred embodiment, the term “oxidation state” refers to states including the neutral state and any state other than a neutral state caused by the gain or loss of electrons (reduction or oxidation). The term “multiple oxidation states” means more than one oxidation state. In preferred embodiments, the oxidation states may reflect the gain of electrons (reduction) or the loss of electrons (oxidation). The terms “different and distinguishable” when referring to two or more oxidation states means that the net charge on the entity (atom, molecule, aggregate, subunit, etc.) can exist in two different states. The states are said to be “distinguishable” when the difference between the states is greater than thermal energy at room temperature (e.g., 0° C. to about 40° C.). The term “tightly coupled” when used in reference to a subunit of a multi-subunit (e.g., polymeric) storage molecule of this invention refers to positioning of the subunits relative to each other such that oxidation of one subunit alters the oxidation potential(s) of the other subunit. In a preferred embodiment the alteration is sufficient such that the (non-neutral) oxidation state(s) of the second subunit are different and distinguishable from the non-neutral oxidation states of the first subunit. In a preferred embodiment the tight coupling is achieved by a covalent bond (e.g., single, double, triple, etc.). However, in certain embodiments, the tight coupling can be through a linker, via an ionic interaction, via a hydrophobic interaction, through coordination of a metal, or by simple mechanical juxtaposition. It is understood that the subunits could be so tightly coupled that the redox processes are those of a single supermolecule. The term “electrode” refers to any medium capable of transporting charge (e.g., electrons) to and/or from a storage molecule. Preferred electrodes are metals or conductive organic molecules. The electrodes can be manufactured to virtually any 2-dimensional or 3-dimensional shape (e.g., discrete lines, pads, planes, spheres, cylinders, etc.). The term “fixed electrode” is intended to reflect the fact that the electrode is essentially stable and unmovable with respect to the storage medium. That is, the electrode and storage medium are arranged in an essentially fixed geometric relationship with each other. It is of course recognized that the relationship alters somewhat due to expansion and contraction of the medium with thermal changes or due to changes in conformation of the molecules comprising the electrode and/or the storage medium. Nevertheless, the overall spatial arrangement remains essentially invariant. In a preferred embodiment this term is intended to exclude systems in which the electrode is a movable “probe” (e.g., a writing or recording “head”, an atomic force microscope (AFM) tip, a scanning tunneling microscope (STM) tip, etc.). The term “working electrode” is used to refer to one or more electrodes that are used to set or read the state of a storage medium and/or storage molecule. The term “reference electrode” is used to refer to one or more electrodes that provide a reference (e.g., a particular reference voltage) for measurements recorded from the working electrode. In preferred embodiments, the reference electrodes in a memory device of this invention are at the same potential although in some embodiments this need not be the case. The term “electrically coupled” when used with reference to a storage molecule and/or storage medium and electrode refers to an association between that storage medium or molecule and the electrode such that electrons move from the storage medium/molecule to the electrode or from the electrode to the storage medium/molecule and thereby alter the oxidation state of the storage medium/molecule. Electrical coupling can include direct covalent linkage between the storage medium/molecule and the electrode, indirect covalent coupling (e.g., via a linker), direct or indirect ionic bonding between the storage medium/molecule and the electrode, or other bonding (e.g., hydrophobic bonding). In addition, no actual bonding may be required and the storage medium/molecule may simply be contacted with the electrode surface. There also need not necessarily be any contact between the electrode and the storage medium/molecule where the electrode is sufficiently close to the storage medium/molecule to permit electron tunneling between the medium/molecule and the electrode. The term “redox-active unit” or “redox-active subunit” refers to a molecule or component of a molecule that is capable of being oxidized or reduced by the application of a suitable voltage. The term “redox-active” molecule refers to a molecule or component of a molecule that is capable of being oxidized or reduced by the application of a suitable voltage. The term “subunit”, as used herein, refers to a redox-active component of a molecule. The term “electrochemical cell” typically refers to a reference electrode, a working electrode, a redox-active molecule (e.g., a storage medium), and, if necessary, some means (e.g., a dielectric) for providing electrical conductivity between the electrodes and/or between the electrodes and the medium. In some embodiments, the dielectric is a component of the storage medium. The terms “memory element”, “memory cell”, or “storage cell” refer to an electrochemical cell that can be used for the storage of information. Preferred “storage cells” are discrete regions of storage medium addressed by at least one and preferably by two electrodes (e.g., a working electrode and a reference electrode). The storage cells can be individually addressed (e.g., a unique electrode is associated with each memory element) or, particularly where the oxidation states of different memory elements are distinguishable, multiple memory elements can be addressed by a single electrode. The memory element can optionally include a dielectric (e.g., a dielectric impregnated with counterions). The term “storage location” refers to a discrete domain or area in which a storage medium is disposed. When addressed with one or more electrodes, the storage location may form a storage cell. However if two storage locations contain the same storage media so that they have essentially the same oxidation states, and both storage locations are commonly addressed, they may form one functional storage cell. “Addressing” a particular element refers to associating (e.g., electrically coupling) that memory element with an electrode such that the electrode can be used to specifically determine the oxidation state(s) of that memory element. The terms “read” or “interrogate” refer to the determination of the oxidation state(s) of one or more molecules (e.g., molecules comprising a storage medium). The phrase “output of an integrated circuit” refers to a voltage or signal produced by a one or more integrated circuit(s) and/or one or more components of an integrated circuit. A “voltammetric device” is a device capable of measuring the current produced in an electrochemical cell as a result of the application of a voltage or change in voltage. An “amperometric device” is a device capable of measuring the current produced in an electrochemical cell as a result of the application of a specific potential field potential (“voltage”). A “potentiometric device” is a device capable of measuring potential across an interface that results from a difference in the equilibrium concentrations of redox molecules in an electrochemical cell. A “coulometric device” is a device capable of the net charge produced during the application of a potential field (“voltage”) to an electrochemical cell. An “impedance spectrometer” is a device capable of determining the overall impedance of an electrochemical cell. A “sinusoidal voltammeter” is a voltammetric device capable of determining the frequency domain properties of an electrochemical cell. The term “porphyrinic macrocycle” refers to a porphyrin or porphyrin derivative. Such derivatives include porphyrins with extra rings ortho-fused, or ortho-perifused, to the porphyrin nucleus, porphyrins having a replacement of one or more carbon atoms of the porphyrin ring by an atom of another element (skeletal replacement), derivatives having a replacement of a nitrogen atom of the porphyrin ring by an atom of another element (skeletal replacement of nitrogen), derivatives having substituents other than hydrogen located at the peripheral (meso-, β-) or core atoms of the porphyrin, derivatives with saturation of one or more bonds of the porphyrin (hydroporphyrins, e.g., chlorins, bacteriochlorins, isobacteriochlorins, decahydroporphyrins, corphins, pyrrocorphins, etc.), derivatives obtained by coordination of one or more metals to one or more porphyrin atoms (metalloporphyrins), derivatives having one or more atoms, including pyrrolic and pyrromethenyl units, inserted in the porphyrin ring (expanded porphyrins), derivatives having one or more groups removed from the porphyrin ring (contracted porphyrins, e.g., corrin, corrole) and combinations of the foregoing derivatives (e.g., phthalocyanines, sub-phthalocyanines, and porphyrin isomers). Preferred porphyrinic macrocycles comprise at least one 5-membered ring. The term “porphyrin” refers to a cyclic structure typically composed of four pyrrole rings together with four nitrogen atoms and two replaceable hydrogens for which various metal atoms can readily be substituted. A typical porphyrin is hemin. The term “multiporphyrin array” refers to a discrete number of two or more covalently-linked porphyrinic macrocycles. The multiporphyrin arrays can be linear, cyclic, or branched. The terms “sandwich coordination compound” or “sandwich coordination complex” refer to a compound of the formula L n M n−1 , where each L is a heterocyclic ligand (as described below), each M is a metal, n is 2 or more, most preferably 2 or 3, and each metal is positioned between a pair of ligands and bonded to one or more hetero atom (and typically a plurality of hetero atoms, e.g., 2, 3, 4, 5) in each ligand (depending upon the oxidation state of the metal). Thus sandwich coordination compounds are not organometallic compounds such as ferrocene, in which the metal is bonded to carbon atoms. The ligands in the sandwich coordination compound are generally arranged in a stacked orientation (i.e., are generally cofacially oriented and axially aligned with one another, although they may or may not be rotated about that axis with respect to one another) (see, e.g., Ng and Jiang (1997) Chemical Society Reviews 26: 433–442). Sandwich coordination complexes include, but are not limited to “double-decker sandwich coordination compound” and “triple-decker sandwich coordination compounds”. The synthesis and use of sandwich coordination compounds is described in detail in U.S. Pat. No. 6,212,093B1. The term “double-decker sandwich coordination compound” refers to a sandwich coordination compound as described above where n is 2, thus having the formula L 1 -M 1 -L 2 , wherein each of L 1 and L 2 may be the same or different (see, e.g., Jiang et al. (1999) J. Porphyrins Phthalocyanines 3: 322–328). The term “triple-decker sandwich coordination compound” refers to a sandwich coordination compound as described above where n is 3, thus having the formula L 1 -M 1 -L 2 -M 2 -L 3 , wherein each of L 1 , L 2 and L 3 may be the same or different, and M 1 and M 2 may be the same or different (see, e.g., Arnold et al. (1999) Chemistry Letters 483–484). A “linker” is a molecule used to couple two different molecules, two subunits of a molecule, or a molecule to a substrate. A “substrate” is a, preferably solid, material suitable for the attachment of one or more molecules. Substrates can be formed of materials including, but not limited to glass, plastic, silicon, germanium, minerals (e.g., quartz), semiconducting materials (e.g., doped silicon, doped germanium, etc.), ceramics, metals, etc. In preferred embodiments, when a metal is designated by “M” or “M n ”, where n is an integer, it is recognized that the metal may be associated with a counterion. A “group II, III, IV, V, or VI element or material” includes the pure element, a doped variant of the group II, III, IV, V, or VI element and/or an oxidized variant of the group II, III, IV, V or VI element. The term “heat-resistant organic molecule” or “heat-stable organic molecule” refers to organic molecules (e.g., porphyrins) that are stable (e.g., show no decomposition, or substantially no decomposition) at temperature of 200° C. to 400° C., preferably at 400° C. for at least 30 seconds, preferably for at least one minute, more preferably for at least 2 to 5 minutes. A “group III, IV, or V substrate” is a material comprising a Group III, IV, or V element. A “a solution comprising a heat resistant organic molecule” is not limited to a true solution, but also includes suspensions, dispersions, and emulsions thereof. In addition, the solution contemplates pastes, gels, aerogels, and essentially any medium suitable for “containing” the heat resistant organic molecule(s). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows illustrative heat-resistant organic molecules for use in the methods of this invention. FIG. 2 illustrates the optimization of concentration of porphyrin alcohol porphyrin-OH) in THF for attachment of the porphyrin to patterned Si—H surfaces. FIG. 3 illustrates the effect of baking time of attachment of porphyrin-OH (compound 104) on Si—H using casting and baking process. Other conditions: 400° C., 1 mM in THF, 100 V/s. FIG. 4 illustrates the optimization of baking temperature for attaching porphyrin alcohol (porphyrin-OH) to patterned Si—H surfaces. Other conditions: 1 mM in THF, 60 minutes, 100 V/s. FIG. 5A shows the cyclic voltammetric behavior of a porphyrin monolayer tethered to Si(100) via a Si—O—C linkage, while FIG. 5B shows the integrated voltammetric signal (corresponding to the charge in the monolayer) plotted as a function of the number of cycles. DETAILED DESCRIPTION I. Coupling an Organic Molecule to a Substrate. This invention pertains to a novel approach to covalently attach organic molecules to a surface of a type II, III, IV, V, or VI material, a doped variant thereof and/or an oxide thereof. In general the method involves: 1) providing a heat resistant organic molecule comprising an attachment group and/or derivatized with an attachment group; and 2) contacting the derivatized heat resistant organic molecule a surface comprising a Group II, III, IV, V, or VI material; and 3) heating the surface and/or molecule to a temperature of at least about 200° C. whereby the attachment group forms a covalent bond with the surface. In certain embodiments, the heat resistant organic molecule is dissolved in an organic solvent (e.g., THF, mesitylene, durene, o-dichlorobenzene, 1,2,4-trichlorobenzene, 1-chloronaphthalene, 2-chloronaphthalene, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, benzonitrile, anisole, and the like). The solvent containing the molecule can then be applied to the surface. Heating can be accomplished by any of a variety of conventional methods. For example, the solvent can be heated before application to the surface. In certain embodiments, both the solvent and the surface can be heated before the solvent is applied to the surface. In certain preferred embodiments, the surface is heated after application of the solvent. This is conveniently accomplished by baking the surface (e.g., in an oven). In certain preferred embodiments, the surface is heated (e.g., baked) under an inert atmosphere (e.g., argon or other inert gas(es)) Various parameters can be optimized for attachment of any particular organic molecule. These include (1) the concentration of the molecule(s), (2) the baking time, and (3) the baking temperature. FIGS. 2 , 3 , and 4 show the results of these studies for a representative porphyrin (molecule 104 in FIG. 1 ). In each figure, the left panel shows the cyclic voltammogram of the covalently attached molecule. The characteristic features of the voltammograms are indicative of covalent attachment and robust electrochemical behavior (see, e.g., Li et al. (2002 Appl. Phys. Lett. 81: 1494–1496; Roth et al. (2003) J. Am. Chem. Soc. 125: 505–517). The right panel shows the molecular coverage. Saturating coverage for this type of molecule is in the range of 10 −10 mol cm −2 . Although the three parameters above are not independent, the figures illustrate the following key observations. First, using the methods described herein, the molecules can be attached at relatively high surface coverage (in the range of 5×10 −11 mol cm −2 ) using micromolar concentrations of materials (see, e.g., FIG. 2 ). Facile attachment using extremely small amounts of material (e.g., concentration less than about 5 mM, preferably less than about 1 mM, more preferably less than about 500 μM or 100 μM, still more preferably less than about 10 μM, and most preferably less than about 1 μM) is distinctly different from other procedures that have been used to anchor molecules to silicon. These procedures typically use very high concentrations of molecules in solution or neat molecules. The use of very small amounts of material indicates that a few grams of information storage molecules could be used to make millions of chips. The use of small amounts of material also indicates that relatively small amounts of organic solvents can be used, thereby minimizing environmental hazards. In addition, it was a surprising discovery that baking times as short as a few minutes (e.g., typically from about 1 sec to about 1 hr, preferably from about 10 sec to about 30 min, more preferably from about 1 minute to about 5, 10, or 15 minutes, and most preferably from about 30 sec to about 1 or 2 minutes) afford high surface coverage ( FIG. 3 ). Short times minimize the amount of energy that is used in the processing step. It was also a surprising discovery that baking temperatures as high as 400° C. can be used with no degradation of the molecules ( FIG. 4 ). This result is of importance in that many processing steps in fabricating CMOS devices entail high temperature processing. In certain embodiments, preferred baking temperatures range from about 125° C. to about 400° C., preferably from about 200° C. to about 400° C., more preferably from about 250° C. to about 400° C., and most preferably from about 300° C. to about 400° C. A further significant point is that diverse functional groups on the information storage molecules are suitable for use in attachment to silicon or other substrates. The groups include, but are not limited to, alcohol, thiol, S-acetylthiol, bromomethyl, allyl, iodoaryl, carboxaldehyde, ethyne, vinyl, hydroxymethyl. It is also noted that such groups such as ethyl, methyl, or arene afforded essentially no attachment as demonstrated by the failure to achieve substantial attachment with the zinc chelates of octaethylporphyrin, meso-tetraphenylporphyrin, meso-tetra-p-tolylporphyrin, and meso-tetramesitylporphyrin. The successful attachment via S-acetylthiol, bromomethyl, iodoaryl, carboxaldehyde, and ethyne is unprecedented. The successful attachment via the iodoaryl group is extraordinarily valuable in affording a direct aryl-Si attachment. The resulting information-storage molecules can be positioned vertically from the surface, which facilitates subsequent patterning. The ability to attach via such diverse functional groups provides great versatility. While in certain embodiments, heating is accomplished by placing the substrate in an oven, essentially any convenient heating method can be utilized, and appropriate heating and contacting methods can be optimized for particular (e.g., industrial) production contexts. Thus, for example, in certain embodiments, heating can be accomplished by dipping the surface in a hot solution containing the organic molecules that are to be attached. Local heating/patterning can be accomplished using for example a hot contact printer, or a laser. Heating can also be accomplished using forced air, a convection oven, radiant heating, and the like. The foregoing embodiments, are intended to be illustrative rather than limiting. II. The Organic Molecules. It was a surprising discovery that a large number of organic molecules, including redox-active organic molecules, are sufficiently heat resistant to be amenable and even quite effective in the methods of this invention. Suitable heat resistant organic molecules typically include, but are not limited to metallocenes (e.g., ferrocene), porphyrins, expanded porphyrins, contracted porphyrins, linear porphyrin polymers, porphyrin sandwich coordination complexes, and porphyrin arrays. Certain preferred heat resistant organic molecules include, but are not limited to 5-[4-(S-acetylthiomethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-[4-(mercaptomethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-[4-(hydroxymethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-[4-(hydroxymethyl)phenyl]-10,15,20-tri-p-tolylporphinatozinc(II), 5-(4-allylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-formylphenyl)-15-phenyl-10,20-di-p-tolylporphinatozinc(II), 5-(4-bromomethylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-ethynylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-iodophenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-bromophenyl)-10,15,20-tri-p-tolylporphinatozinc(II), 5-(4-hydroxyphenyl)-10,15,20-trimesitylporphinatozinc(II), 5,10-bis(4-ethynylphenyl)-15,20-dimesitylporphinatozinc(II), 5-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5-iodo-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5,10-bis(4-iodophenyl)-15,20-dimesitylporphinatozinc(II), 5-[4-(2-(trimethylsilyl)ethynyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5,15-bis(4-ethynylphenyl)-10,20-dimesitylporphinatozinc(II), 5,15-bis(4-iodophenyl)-10,20-dimesitylporphinatozinc(II), 5,10,15-tris(4-ethynylphenyl)-20-mesitylporphinatozinc(II), 5,15-bis(4-ethynylphenyl)-10,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5,15-bis(4-ethynylphenyl)porphinatozinc(II), 5,15-bis(3-ethynylphenyl)-10,20-dimesitylporphinatozinc(II), 5,10,15,20-tetrakis(4-ethynylphenyl)porphinatozinc(II), 5,10-bis[4-(2-(trimethylsilyl)ethynyl)phenyl]-15,20-dimesitylporphinatozinc(II), 5-(3,5-diethynylphenyl)-10,15,20-trimesitylporphinatozinc(II), 3,7-dibromo-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5-[4-(2-(trimethylsilyl)ethynyl)phenyl]-10,15,20-tri-p-tolylporphinatozinc(II), 5-[4-(Se-acetylselenomethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-(4-iodophenyl)-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5,10-bis(4-ethynylphenyl)-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5,10-bis(4-ethynylbiphen-4′-yl)-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5-(4-vinylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-vinylphenyl)-10,15,20-tri-p-tolylporphinatozinc(II), 5-(hydroxymethyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-allylphenyl)-10,15,20-tri-p-tolylporphinatozinc(II), 5-(4-allylphenyl)-10,15,20-tri-p-tolylporphinatocopper(II), type c triple decker [(tert-butyl) 4 phthalocyaninato]Eu[(tert-butyl) 4 phthaloxyaninato]Eu[5,15-bis(4-ethynylphenyl)-10,20-bis(4-tert-butylphenyl)porphyrin], type c triple decker [(tert-butyl) 4 phthalocyaninato]Eu[(tert-butyl) 4 phthaloxyaninato]Eu[5-[4-[2-(4-(hydroxymethyl)phenyl)ethynyl]phenyl]-10,15,20-tri-p-tolylporphyrin]5,10-bis[4-(2-(triisopropylsilyl)ethynyl)biphen-4′-yl]-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5,10-bis[4-(2-(triisopropylsilyl)ethynyl)phenyl]-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), and the like. The suitablility of particular molecules for use in the methods of this invention can readily be determined. The molecule(s) of interest are simply coupled to a surface (e.g., a hydrogen passivated surface) according to the methods of this invention. Then sinusoidal voltammetry can be performed (e.g., as described herein or in U.S. Pat. Nos. 6,272,038, 6,212,093, and 6,208,553, PCT Publication WO 01/03126, or by (Roth et al. (2000) Vac. Sci. Technol. B 18: 2359–2364; Roth et al. (2003) J. Am. Chem. Soc. 125: 505–517) to evaluate 1) whether or not the molecule(s) coupled to the surface, 2) the degree of coverage (coupling); and 3) whether or not the molecule degraded during the coupling procedure. Table 1 illustrates the test results (electrochemical characteristics) of a number of porphyrins examined using the attachment procedure described herein. For those porphyrins that attached a subjective EGFP scale was used to rate their electrochemical behavior. TABLE 1 Electrochemical behavior of porphyrins attached to a silicon substrate according to the methods described herein. All substituents are at the p-position, and each compound bears one substituent unless noted otherwise. cmpd # Result Structural element (non-linking units) 16 excellent ZnP—PhCH 2 SAc (mesityl) 104 excellent ZnP—PhCH 2 OH (mesityl) 115 excellent ZnP—PhCH 2 OH (p-tolyl) 132 good TD-dpe-CH 2 OH 141 excellent ZnP—Ph-allyl (mesityl) 153 no attachment ZnTPP 172 excellent ZnP—Ph—CHO (p-tolyl; phenyl) 178 excellent ZnP—PhCH 2 Br (mesityl) 181 no attachment ZnTTP 182 no attachment ZnTMP 183 no attachment ZnOEP 184 excellent ZnP—PhCCH (mesityl) 185 good ZnP—PhI (mesityl) 189 Fair ZnP—PhBr (p-tolyl) 191 excellent ZnP—PhOH (mesityl) 192 excellent cis-ZnP—(PhCCH) 2 (mesityl) (polymer) 193 Fair ZnP—Ph—B(OR) 2 (mesityl; 3,5-di-t-BuPh) 194 Fair ZnP—I (mesityl; 3,5-di-t-BuPh) 195 good cis-ZnP—(PhI) 2 (mesityl) 196 excellent ZnP—PhCC-TMS (mesityl) 197 excellent trans-ZnP—(PhCCH) 2 (mesityl) (polymer) 189 good trans-ZnP—(PhI) 2 (mesityl) 199 good (polymer) ZnP—(PhCCH) 3 (mesityl) 200 good trans-ZnP—(PhCCH) 2 (p-t-BuPh) 201 poor trans-ZnP—(PhCCH) 2 (H) 202 good trans-ZnP-m-(PhCCH) 2 (mesityl) 204 poor ZnP—(PhCCH) 4 205 Fair TD-(PhCCH) 2 206 excellent trans-ZnP—(PhCC-TMS) 2 (mesityl) 207 good ZnP—Ph-3,5-(CCH) 2 (mesityl) 208 poor ZnP-3,7-Br 2 (mesityl; 3,5-di-t-BuPh) 209 excellent ZnP-CC-TMS (p-tolyl) *ZnP is a zinc porphyrin. TD is a triple-decker lanthanide sandwich coordination compound (e.g., as described in U.S. Pat. No. 6,212,093). It is noted that the above-described compounds are meant to be illustrative and not limiting. Other suitable compounds can readily be ascertained using routine screening procedures as described herein. It is also noted that where certain organic molecules decompose at particular sites at high temperature (e.g., 200° C. to 400° C.) the “reactive” site can often be derivatized with a stable protecting group. The molecule can be coupled to the surface according to the methods of this invention and the protecting group can then be chemically removed from the organic molecule. The organic molecule is typically provided in a solvent, dispersion, emulsion, paste, gel, or the like. Preferred solvents, pastes, gels, emulsions, dispersions, etc., are solvents that can be applied to the Group II, III, IV, V, and/or VI material(s) without substantially degrading that substrate and that solubilize or suspend, but do not degrade the organic molecule(s) that are to be coupled to the substrate. In certain embodiments, preferred solvents include high boiling point solvents (e.g., solvents with an initial boiling point greater than about 130° C., preferably greater than about 150° C., more preferably greater than about 180° C.). Such solvents include, but are not limited to benzonitrile, dimethylformamide, zylene, orthodichlorobenzene, and the like. III. The Attachment Molecules. To effect attachment to the substrate (e.g., a Group II, III, IV, V, or VI element, semiconductor, and/or oxide) the heat resistant organic molecule either bears one or more attachment group(s) (e.g., as substituent(s)) and/or is derivatized so that it is attached directly or through a linker to one or more attachment groups. A wide variety of attachment molecules (groups) are suitable for use in the methods of this invention. Such attachment groups include, but are not limited to alcohols, thiols, S-acetylthiols, bromomethyls, allyls, iodoaryls, carboxaldehydes, ethynes, and the like. In certain embodiments, the attachment groups include, but are not limited to 4-(hydroxymethyl)phenyl, 4-(S-acetylthiomethyl)phenyl, 4-(Se-acetylselenomethyl)phenyl, 4-(mercaptomethyl)phenyl, 4-(hydroselenomethyl)phenyl, 4-formylphenyl, 4-(bromomethyl)phenyl, 4-vinylphenyl, 4-ethynylphenyl, 4-allylphenyl, 4-[2-(trimethylsilyl)ethynyl]phenyl, 4-[2-(triisopropylsilyl)ethynyl]phenyl, 4-bromophenyl, 4-iodophenyl, 4-hydroxyphenyl, 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl bromo, iodo, hydroxymethyl, S-acetylthiomethyl, Se-acetylselenomethyl, mercaptomethyl, hydroselenomethyl, formyl, bromomethyl, chloromethyl, ethynyl, vinyl, allyl, 4-[2-(4-(hydroxymethyl)phenyl)ethynyl]phenyl, 4-(ethynyl)biphen-4′-yl, 4-[2-(triisopropylsilyl)ethynyl]biphen-4′-yl, 3,5-diethynylphenyl, 2-bromoethyl, and the like. These attachment groups are meant to be illustrative and not limiting. The suitability of other attachment groups can readily be evaluated. A heat resistant organic molecule bearing the attachment group(s) of interest (directly or on a linker) is coupled to a substrate (e.g., hydrogen-passivated Si) according to the methods described herein. The efficacy of attachment can then be evaluated electrochemically, e.g., using sinusoidal voltammetry as described above. The attachment groups can be substituent(s) comprising the heat-resistant organic molecule. Alternatively, the organic molecule can be derivatized to covalently link the attachment group(s) thereto either directly or through a linker. Means of derivatizing molecules, e.g., with alcohols or thiols are well known to those of skill in the art (see, e.g., Gryko et al. (1999) J. Org. Chem., 64: 8635–8647; Smith and March (2001) March's Advanced Organic Chemistry , John Wiley & Sons, 5th Edition, etc.). Where the attachment group comprises an alcohol, in certain embodiments, suitable alcohols include, but are not limited to a primary alcohol, a secondary alcohol, a tertiary alcohol, a benzyl alcohol, and an aryl alcohol (i.e., a phenol). Certain particularly preferred alcohols include, but are not limited to 2 to 10 carbon straight chain alcohols, benzyl alcohol, and phenethyl alcohol. When the attachment group comprises a thiol, in certain embodiments, suitable thiols include, but are not limited to a primary thiol, a secondary thiol, a tertiary thiol, a benzyl thiol, and an aryl thiol. Particularly preferred thiols include, but are not limited to 2 to 10 carbon straight chain thiols, benzyl thiol, and phenethyl thiol. IV. The Substrate. The methods of this invention are suitable for covalently coupling organic molecules to essentially any or all Group II, III, IV, V, or VI materials (e.g., Group II, III, IV, V, or VI elements, semiconductors, and/or oxides thereof), more preferably to essentially any or all Group III, IV, or V materials (e.g., carbon, silicon, germanium, tin, lead), doped Group II, III, IV, V, and VI elements, or oxides of pure or doped Group II, III, IV, V, or VI elements. In certain preferred embodiments the surface is Group III, IV, or V material, more preferably a Group IV material (oxide, and/or doped variant), still more preferably a silicon or germanium surface or a doped and/or oxidized silicon or germanium surface. The group II, III, IV, V, or VI element can be essentially pure, or it can be doped (e.g., p- or n-doped). P- and n-dopants for use with Group II–VI elements, in particular for use with Groups III, IV, and V elements, more particularly for use with Group IV elements (e.g., silicon, germanium, etc.) are well known to those of skill in the art. Such dopants include, but are not limited to phosphorous compounds, boron compounds, arsenic compounds, aluminum compounds, and the like. Many doped Group II, III, IV, V, or VI elements are semiconductors and include, but are not limited to ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, GaN, GaP, GaAs, GaSb, InP, InAs, InSb, AlS, AlP, AlSb, PbS, PbSe, Ge and Si and ternary and quaternary mixtures thereof. The surface can take essentially any form. For example, it can be provided as a planar substrate, an etched substrate, a deposited domain on another substrate and the like. Particularly preferred forms include those forms of common use in solid state electronics fabrication processes. Although not necessarily required, in certain embodiments the surface is cleaned before use, e.g., using standard methods known to those of skill in the art. Thus, for example, in one preferred embodiment, the surface can be cleaned by sonication in a series of solvents (e.g., acetone, toluene, acetone, ethanol, and water) and then exposed to a standard wafer-cleaning solution (e.g., Piranha (sulfuric acid: 30% hydrogen peroxide, 2:1)) at an elevated temperature (e.g., 100° C.). In certain embodiments, oxides can be removed from the substrate surface and the surface can be hydrogen passivated. A number of approaches to hydrogen passivation are well known to those of skill in the art. For example, in one approach, a flow of molecular hydrogen is passed through dense microwave plasma across a magnetic field. The magnetic field serves to protect the sample surface from being bombarded by charged particles. Hence the crossed beam (CB) method makes it possible to avoid plasma etching and heavy ion bombardment that are so detrimental for many semiconductor devices (see, e.g., Balmashnov, et al. (1990) Semiconductor Science and Technology, 5: 242). In one particularly preferred embodiment, passivation is by contacting the surface to be passivated with an ammonium fluoride solution (preferably sparged of oxygen). Other methods of cleaning and passivating surfaces are known to those of skill in the art (see, e.g., Choudhury (1997) The Handbook of Microlithography, Micromachining, and Microfabrication , Soc. Photo-Optical Instru. Engineer, Bard & Faulkner (1997) Fundamentals of Microfabrication , and the like). V. Patterning the Organic Molecule(s) on the Substrate In certain embodiments, the heat-resistant organic molecules are attached to form a uniform film across the surface of the Group II, III, IV, V, or VI material. In other embodiments, the organic molecules are separately coupled at one or more discrete locations on the surface. In certain embodiments, different molecules are coupled at different locations on the surface. The location at which the molecules are coupled can be accomplished by any of a number of means. For example, in certain embodiments, the solution(s) comprising the organic molecule(s) can be selectively deposited at particular locations on the surface. In certain other embodiments, the solution can be uniformly deposited on the surface and selective domains can be heated. In certain embodiments, the organic molecules can be coupled to the entire surface and then selectively etched away from certain areas. The most common approach to selectively contacting the surface with the organic molecule(s) involves masking the areas of the surface that are to be free of the organic molecules so that the solution containing the molecule(s) cannot come in contact with those areas. This is readily accomplished by coating the substrate with a masking material (e.g., a polymer resist) and selectively etching the resist off of areas that are to be coupled. Alternatively a photoactivatible resist can be applied to the surface and selectively activated (e.g., via UV light) in areas that are to be protected. Such “photolithographic” methods are well known in the semiconductor industry (see e.g., Van Zant (2000) Microchip Fabrication: A Practical Guide to Semiconductor Processing ; Nishi and Doering (2000) Handbook of Semiconductor Manufacturing Technology ; Xiao (2000) Introduction to Semiconductor Manufacturing Technology ; Campbell (1996) The Science and Engineering of Microelectronic Fabrication ( Oxford Series in Electrical Engineering ), Oxford University Press, and the like). In addition, the resist can be patterned on the surface simply by contact printing the resist onto the surface. Other approaches involve contact printing of the reagents, e.g., using a contact printhead shaped to selectively deposit the reagent(s) in regions that are to be coupled, use of an inkjet apparatus (see e.g., U.S. Pat. No. 6,221,653) to selectively deposit reagents in particular areas, use of dams to selectively confine reagents to particular regions, and the like. In certain preferred embodiments, the coupling reaction is repeated several times. After the reaction(s) are complete, uncoupled organic molecules are washed off of the surface, e.g., using standard wash steps (e.g., benzonitrile wash followed by sonication in dry methylene chloride). The foregoing methods are intended to be illustrative. In view of the teachings provided herein, other approaches will be evident to those of skill in the semiconductor fabrication arts. VI. High Charge Density Materials. It was a surprising discovery of this invention that coupling of redox-active molecules to a doped or undoped substrate (e.g., a substrate comprising a group III, IV, or V element) results in higher and more uniform packing of the organic molecules (e.g., redox-active species) than other previously known methods. With redox-active organic molecules this manifests as lower oxidative current at higher anodic potentials observed in voltammetric measurements. In addition, a cyclic voltammogram shows sharper and more symmetric peaks. In addition, the improved uniformity and higher packing density of redox-active molecules on the substrate results in materials capable of storing a significantly higher charge density. Thus, in preferred embodiments, this invention provides a group IV element substrate having coupled thereto one or more redox-active species that can store charge at a charge density of at least about 75 μCoulombs/cm 2 , preferably at least about 100 μCoulombs/cm 2 , more preferably at least about 150 μCoulombs/cm 2 , and most preferably of at least about 200 or 250 μCoulombs/cm 2 per non-zero oxidation state of the redox-active molecules. Such materials are useful in the fabrication of molecular memories (memory chips). Where various binding moieties are used instead of redox-active species, the high uniformity and molecule density provides sensors having greater sensitivity and selectivity for a particular analyte. VII. Uses of Organic Molecules Coupled to a Group IV Material. The methods of this invention can be used to attach essentially any heat-resistant organic molecule to a Group II, III, IV, V, or VI material surface, preferably to a Group III, IV, or V surface. In certain preferred embodiments, the molecule is a redox-active molecule and can be used to form a molecular memory. In other preferred embodiments, the molecule can be essentially any other heat-resistant molecule. Certain other heat-resistant molecules include, but are not limited to binding partner (e.g., certain antibodies, ligands, nucleic acids, sugars, etc.) and can be used to form a sensor for detecting particular analyte(s). In “molecular memory” redox-active molecules (molecules having one or more non-zero redox states) coupled to the Group II, III, IV, V, or VI materials are used to store bits (e.g., each redox state can represent a bit). The redox-active molecule attached to the substrate material (e.g., silicon, germanium, etc.) forms a storage cell capable of storing one or more bits in various oxidation states. In certain embodiments, the storage cell is characterized by a fixed electrode electrically coupled to a “storage medium” comprising one or more redox-active molecules and having a multiplicity of different and distinguishable oxidation states. Data is stored in the (preferably non-neutral) oxidation states by the addition or withdrawal of one or more electrons from said storage medium via the electrically coupled electrode. The oxidation state of the redox-active molecule(s) can be set and/or read using electrochemical methods (e.g., cyclic voltammetry), e.g., as described in U.S. Pat. Nos. 6,272,038, 6,212,093, and 6,208,553 and PCT Publication WO 01/03126. Because group II, III, IV, V, and VI materials, in particular group IV materials (e.g., silicon, germanium, etc.), are commonly used in electronic chip fabrication, the methods provided herein readily lend themselves to the fabrication of molecular memory chips compatible with existing processing/fabrication technologies. In addition, details on the construction and use of storage cells comprising redox-active molecules can be found, in U.S. Pat. Nos. 6,272,038, 6,212,093, and 6,208,553 and PCT Publication WO 01/03126. Certain preferred redox-active molecules suitable for use in this invention are characterized by having a multiplicity of oxidation states. Those oxidation states are provided by one or more redox-active units. A redox-active unit refers to a molecule or to a subunit of a molecule that has one or more discrete oxidation states that can be set by application of an appropriate voltage. Thus, for example, in one embodiment, the redox-active molecule can comprise two or more (e.g., 8) different and distinguishable oxidation states. Typically, but not necessarily, such multi-state molecules will be composed of several redox-active units (e.g., porphyrins or ferrocenes). Each redox-active molecule is itself at least one redox-active unit, or comprises at least one redox-active unit, but can easily comprise two or more redox-active units. Preferred redox-active molecules include, but are not limited to porphyrinic macrocycles. Particularly preferred redox-active molecules include a porphyrin, an expanded porphyrin, a contracted porphyrin, a ferrocene, a linear porphyrin polymer, a porphyrin sandwich coordination complex, and a porphyrin array. In certain embodiments, the redox-active molecule is a metallocene as shown in Formula I. where L is a linker, M is a metal (e.g., Fe, Ru, Os, Co, Ni, Ti, Nb, Mn, Re, V, Cr, W), S 1 and S 2 are substituents independently selected from the group consisting of aryl, phenyl, cycloalkyl, alkyl, halogen, alkoxy, alkylthio, perfluoroalkyl, perfluoroaryl, pyridyl, cyano, thiocyanato, nitro, amino, alkylamino, acyl, sulfoxyl, sulfonyl, imido, amido, and carbamoyl. In preferred embodiments, a substituted aryl group is attached to the porphyrin, and the substituents on the aryl group are selected from the group consisting of aryl, phenyl, cycloalkyl, alkyl, halogen, alkoxy, alkylthio, perfluoroalkyl, perfluoroaryl, pyridyl, cyano, thiocyanato, nitro, amino, alkylamino, acyl, sulfoxy, sulfonyl, imido, amido, and carbamoyl. Certain suitable substituents include, but are not limited to, 4-chlorophenyl, 3-acetamidophenyl, 2,6-dichloro-4-trifluoromethyl, and the like. Preferred substituents provide a redox potential range of less than about 2 volts. X is selected from the group consisting of a substrate, a reactive site that can covalently couple to a substrate (e.g., an alcohol, a thiol, etc.). It will be appreciated that in some embodiments, L-X is an alcohol or a thiol. In certain instances L-X can be replaced with another substituent (S 3 ) like S 1 or S 2 . In certain embodiments, L-X can be present or absent, and when present preferably is 4-hydroxyphenyl, 4-(2-(4-hydroxyphenyl)ethynyl)phenyl, 4-(hydroxymethyl)phenyl, 4-mercaptophenyl, 4-(2-(4-mercaptophenyl)ethynyl)phenyl, 4-mercaptomethylphenyl, 4-hydroselenophenyl, 4-(2-(4-hydroselenophenyl)ethynyl)phenyl, 4-hydrotellurophenyl, 4-(hydroselenomethyl)phenyl, 4-(2-(4-hydrotellurophenyl)ethynyl)phenyl, 4-(hydrotelluromethyl)phenyl, and the like. The oxidation state of molecules of Formula I is determined by the metal and the substituents. Various suitable metallocenes are disclosed in U.S. Pat. Nos. 6,272,038, 6,212,093, and 6,208,553, and PCT Publication WO 01/03126. Other suitable redox-active molecules include, but are not limited to porphyrins illustrated by Formula II. where, F is a redox-active subunit (e.g., a ferrocene, a substituted ferrocene, a metalloporphyrin, or a metallochlorin, etc.), J 1 is a linker, M is a metal (e.g., Zn, Mg, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Rh, Ir, Mn, B, Al, Ga, Pb, and Sn), S 1 and S 2 are independently selected from the group consisting of aryl, phenyl, cycloalkyl, alkyl, halogen, alkoxy, alkylthio, perfluoroalkyl, perfluoroaryl, pyridyl, cyano, thiocyanato, nitro, amino, alkylamino, acyl, sulfoxyl, sulfonyl, imido, amido, and carbamoyl wherein said substituents provide a redox potential range of less than about 2 volts, K 1 , K 2 , K 3 , and K 4 are independently selected from the group consisting of N, O, S, Se, Te, and CH; L is a linker; X is selected from the group consisting of a substrate, a reactive site that can covalently couple to a substrate. In preferred embodiments, X or L-X is an alcohol or a thiol. In some embodiments L-X can be eliminated and replaced with a substituent independently selected from the same group as S 1 or S 2 . Other suitable molecules include, but are not limited to 5-[4-(S-acetylthiomethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-[4-(mercaptomethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-[4-(hydroxymethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-[4-(hydroxymethyl)phenyl]-10,15,20-tri-p-tolylporphinatozinc(II), 5-(4-allylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-formylphenyl)-15-phenyl-10,20-di-p-tolylporphinatozinc(II), 5-(4-bromomethylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-ethynylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-iodophenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-bromophenyl)-10,15,20-tri-p-tolylporphinatozinc(II), 5-(4-hydroxyphenyl)-10,15,20-trimesitylporphinatozinc(II), 5,10-bis(4-ethynylphenyl)-15,20-dimesitylporphinatozinc(II), 5-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5-iodo-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5,10-bis(4-iodophenyl)-15,20-dimesitylporphinatozinc(II), 5-[4-(2-(trimethylsilyl)ethynyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5,15-bis(4-ethynylphenyl)-10,20-dimesitylporphinatozinc(II), 5,15-bis(4-iodophenyl)-10,20-dimesitylporphinatozinc(II), 5,10,15-tris(4-ethynylphenyl)-20-mesitylporphinatozinc(II), 5,15-bis(4-ethynylphenyl)-10,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5,15-bis(4-ethynylphenyl)porphinatozinc(II), 5,15-bis(3-ethynylphenyl)-10,20-dimesitylporphinatozinc(II), 5,10,15,20-tetrakis(4-ethynylphenyl)porphinatozinc(II), 5,10-bis[4-(2-(trimethylsilyl)ethynyl)phenyl]-15,20-dimesitylporphinatozinc(II), 5-(3,5-diethynylphenyl)-10,15,20-trimesitylporphinatozinc(II), 3,7-dibromo-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5-[4-(2-(trimethylsilyl)ethynyl)phenyl]-10,15,20-tri-p-tolylporphinatozinc(II), 5-[4-(Se-acetylselenomethyl)phenyl]-10,15,20-trimesitylporphinatozinc(II), 5-(4-iodophenyl)-10,20-bis(3,5-di-tert-butylphenyl)-15-mesitylporphinatozinc(II), 5,10-bis(4-ethynylphenyl)-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5,10-bis(4-ethynylbiphen-4′-yl)-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5-(4-vinylphenyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-vinylphenyl)-10,15,20-tri-p-tolylporphinatozinc(II), 5-(hydroxymethyl)-10,15,20-trimesitylporphinatozinc(II), 5-(4-allylphenyl)-10,15,20-tri-p-tolylporphinatozinc(II), 5-(4-allylphenyl)-10,15,20-tri-p-tolylporphinatocopper(II), type c triple decker [(tert-butyl) 4 phthalocyaninato]Eu[(tert-butyl) 4 phthalocyaninato]Eu[5,15-bis(4-ethynylphenyl)-10,20-bis(4-tert-butylphenyl)porphyrin], type c triple decker [(tert-butyl) 4 phthalocyaninato]Eu[(tert-butyl) 4 phthalocyaninato]Eu[5-[4-[2-(4-(hydroxymethyl)phenyl)ethynyl]phenyl]-10,15,20-tri-p-tolylporphyrin]5,10-bis[4-(2-(triisopropylsilyl)ethynyl)biphen-4′-yl]-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), 5,10-bis[4-(2(triiosopropylsilyl)ethynyl)phenyl]-15,20-bis(4-tert-butylphenyl)porphinatozinc(II), and the like. Control over the hole-storage and hole-hopping properties of the redox-active units of the redox-active molecules used in the memory devices of this invention allows fine control over the architecture of the memory device. Such control is exercised through synthetic design. The hole-storage properties depend on the oxidation potential of the redox-active units or subunits that are themselves or that are used to assemble the redox-active storage media used in the devices of this invention. The hole-storage properties and redox potential can be tuned with precision by choice of base molecule(s), associated metals and peripheral substituents (Yang et al. (1999) J. Porphyrins Phthalocyanines, 3: 117–147). The design of molecules for molecular memory is discussed in detail in U.S. Pat. Nos. 6,272,038, 6,212,093, and 6,208,553, and PCT Publication WO 01/03126. VIII. Kits. In still another embodiment, this invention provides kits for practice of the method of this invention or for use of the materials produced by methods of this invention. In one embodiment, the kit comprises one or more reagents used to couple an organic molecule to a type II, III, IV, V, or VI material according to the methods of this invention. Such reagents include, but are not limited to reagents for cleaning and/or passivating the material surface, and/or the organic molecule(s) that are to be coupled to the surface, and/or attachment molecules for derivatizing the organic molecule(s) (e.g., reagents for derivatizing an organic molecule with an alcohol or a thiol), and/or solvents for use in coupling the derivatized organic molecule to the surface, and/or reagents for washing the derivatized surface, and the like In certain embodiments, the kits comprise a type II, III, IV, V, or VI material having a heat-resistant organic molecule (e.g., a redox-active molecule) coupled thereto as described herein. The type II, III, IV, V, or VI material can, in certain embodiments, comprise a molecular memory and in, certain embodiments, comprise a sensor. In addition, the kits can optionally include instructional materials containing directions (i.e., protocols) for the practice of the methods of this invention. Preferred instructional materials provide protocols utilizing the kit contents for coupling a heat-resistant organic molecule to a type II, III, IV, V, or VI material according to the methods of this invention, and/or for using type II, III, IV, V, or VI materials having coupled organic molecules as memory elements or as sensors. While the instructional materials typically comprise written or printed materials they are not limited to such. Any medium capable of storing such instructions and communicating them to an end user is contemplated by this invention. Such media include, but are not limited to electronic storage media (e.g., magnetic discs, tapes, cartridges, chips), optical media (e.g., CD ROM), and the like. Such media may include addresses to internet sites that provide such instructional materials. EXAMPLES The following examples are offered to illustrate, but not to limit the claimed invention. Example 1 Molecules Can Perform in Electronic Devices Under Real-World Processing and Operating Conditions The central tenet of the field of molecular electronics is that molecular components can be used as functional elements in place of the semiconductor-based devices present in conventional microcircuitry (Kwok and Ellenbogen (2002) Materials Today, 28–37; Carroll and Gorman (2002) Angew. Chem. Int. Ed. 41: 4378–4400). To serve in this role, the molecular components should remain robust under daunting conditions including high-temperature (e.g., 400° C.) processing steps during manufacture and very large numbers (10 9 –10 12 ) of operational cycles over a lifetime ( International Technology Roadmap for Semiconductors ( ITRS ), Semiconductor Industry Association, San Jose, Calif. (2000)). There has been considerable skepticism whether molecular materials possess adequate stability to meet such requirements. Herein, we demonstrate that porphyrin-based information storage media meet the processing and operating challenges required for use in computational devices. Our approach for molecular-based information storage employs redox-active porphyrin molecules as charge-storage elements (Roth et al. (2000) Vac. Sci. Technol. B 18: 2359–2364). We have shown that these molecules can be covalently attached to device-grade silicon platforms to form the basis of first-generation hybrid molecular/semiconductor devices (Roth et al. (2003) J. Am. Chem. Soc. 125: 505–517). The porphyrin-based information storage elements exhibit charge-retention times that are long (minutes) compared with those of the semiconductor elements in dynamic random access memory (milliseconds) (Roth et al. (2000) Vac. Sci. Technol. B 18: 2359–2364; Roth et al. (2003) J. Am. Chem. Soc. 125: 505–517). These molecules also exhibit redox characteristics that make them amenable for use as multibit information-storage media. FIG. 5A shows the cyclic voltammetric behavior of a porphyrin monolayer tethered to Si(100) via a Si—O—C linkage. This monolayer was formed by placing a small amount (˜1 μL) of a dilute solution (˜100 μM) on a micron-scale photolithographically patterned, hydrogen-passivated Si(100) platform and baking the sample at 400° C. for several minutes under inert atmosphere conditions. The voltammetric response of the porphyrin monolayer is identical to that of porphyrin monolayers formed at much lower temperatures (100–170° C. for several hours) (Roth et al. (2003) J. Am. Chem. Soc. 125: 505–517) and demonstrates that molecular integrity is maintained at temperatures where most organic molecules thermally decompose. The high-temperature procedure is readily adaptable to current semiconductor fabrication technology and has the important added benefit that extremely small quantities of material are needed to make a device. The robustness of the porphyrin information-storage medium was examined by repeatedly performing the cycle of (1) oxidizing the electrically neutral monolayer and (2) reducing the resulting positively charged monolayer to its electrically neutral state. The oxidation event is equivalent to writing a bit of information; the reduction event is equivalent to erasing or destructively reading out the information. The five voltammograms in FIG. 5A show the response of the system after 0, 2.5×10 4 , 1.8×10 6 , 1.1×10 9 , and 1.0×10 10 oxidation/reduction cycles. During the experiment, the nature of the electrical cycling was varied. On some days, the system was continuously cycled for 24 hrs. On others, cycling was stopped intentionally for periods ranging from a few minutes up to 12 hrs. At one point, cycling was stopped unintentionally due to an electrical power failure. The data indicate that after an initial “burn-in” period of ˜10 7 cycles the voltammetric response stabilizes. This robustness of the system is further illustrated in FIG. 5B wherein the integrated voltammetric signal (corresponding to the charge in the monolayer) is plotted as a function of the number of cycles. These data indicate that the charge-storage characteristics of the monolayer exhibit minimal variation (few percent) over the course of the entire experiment. At the time cycling was arbitrarily stopped (>10 10 cycles; ˜27 days), the system showed no signs of degradation. Collectively, these data indicate that the porphyrin-based information storage medium is extremely robust and augur well for the use of selected molecules in hybrid molecular/semiconductor electronic devices. It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes.

This invention provides a new procedure for attaching molecules to semiconductor surfaces, in particular silicon. The molecules, which include, but are not limited to porphyrins and ferrocenes, have been previously shown to be attractive candidates for molecular-based information storage. The new attachment procedure is simple, can be completed in short times, requires minimal amounts of material, is compatible with diverse molecular functional groups, and in some instances affords unprecedented attachment motifs. These features greatly enhance the integration of the molecular materials into the processing steps that are needed to create hybrid molecular/semiconductor information storage devices.

This application claims the benefit of U.S. Provisional Application No. 61/062,219, filed Jan. 24, 2008, which is hereby incorporated by reference in its entirety. SUMMARY OF THE INVENTION The invention provides apparatus to control the movement of heat and moisture and control temperature and humidity, by evaporation and air cooling with air flow between an armor shell, apparel, or helmet covering human or animal body using; air flow channels, water wicking material covered heat pipes, or thermal conductors in contact with human or animal body and humidity and/or temperature reactive auto-actuated laminate impedance structures or humidity and/or temperature reactive auto-actuated laminate valves. The invention provides apparatus to control the movement of heat and chemicals and thereby control temperature and humidity, by evaporation and air cooling with fluid flow between a cover over a living body using fluid flow channels, liquid wicking material covered thermal conduits in contact with living body, and chemical concentration and/or temperature reactive auto-actuated laminate structures with varying impedance to the movement of heat and chemicals. The invention provides apparatus to control heat and moisture flux to control temperature and humidity environment, by evaporation and air cooling with airflow between an armor shell, apparel, or helmet covering a living body using; air flow channels, water wicking material covered thermal conduits in contact with body, and humidity and/or temperature reactive auto-actuated laminate impedance structures which therein vary impedance to the flux of heat, moisture and/or fluid flow. Elements: remove heat and chemicals, or moisture control temperature and humidity, evaporation and air cooling with air flow between an armor shell, apparel, or helmet covering air flow channels chemical concentration and/or temperature reactive auto-actuated laminate structures which control heat and air flow wicking material covered heat thermal conduits, heat pipes, or conductor which is also in contact with the human, animal, or living body. The use of body armor, helmets, fire proof suits, hazardous environment suits, cock pit shells, thick garments, shoes, and gloves on people such as motor cross racing drivers, racing car drivers, soldiers, police, and firefighters can lead to excessive temperatures on the wearers body. The human body reaction to maintain constant temperature is to sweat and cool by evaporation on the skin. Due to the confined conditions and lack of air circulation under the armor the sweating does not result in evaporation and effective cooling of the wearer. Thus sweat builds up under the armor and the wearer becomes uncomfortable, this can result in dehydration, in some situations even possibly lead to hyperthermia or hypothermia. In addition the moist and warm conditions on the skin are ideal growth conditions for bacterial growth and can lead to skin and wound infections of the wearers. Body oils from the wearer can also interfere with efficient wicking of sweat. In cold weather environments excessive cooling through body armor can also lead to an opposite situation of chilling the wearer of the armor. The disclosed invention is to provide a means of wicking sweat off the body and skin onto a wicking surface covering the padding or of the of the body armor, and creating air flow passages in the padding of the helmet or body armor to allow for effective cooling by evaporation of the sweat from the wearer. Padding contact and confinement of the body armor interferes with the normal evaporative cooling of sweating and evaporation to air flow. By placing thermally conductive materials, or heat pipes inside the padding to transfer heat on contact with the body and with the evaporating sweat areas onto the wicking surfaces it restores the cooling effect of sweating. To provide optimum heat removal control to maintain desirable temperatures and humidity surrounding the wearer, humidity or temperature bi-material laminate actuating valves open to let air flow when temperatures or humidity are high to maximize air flow and evaporation and close when the temperatures are low or humidity is low to retain heat and maintain a comfortable environment about the wearer. The laminate actuators can be distributed through out the air vent channels under the body armor to achieve local control thereby uniformly maintaining desirable environmental conditions through out the apparel. Laminate actuators in the form of exterior layers or fabric can be used to cover the exterior of the body armor or helmet to act as self adjusting variable thermal insulation and ventilation to the body armor and thermally conductive elements. To insure the cooling effect of flowing air in high humidity environments water absorbent and heat dissipation an air intake filter be used to de-humidify the air flow entering the system. The air intake filter can also be an insect, dust and/or bacterial filter to keep the air flow space inside the armor clean. An air fan can be used to pump air through the system when the system is stationary or high power cooling performance is needed or the air flow resistance into passages will not allow sufficient evaporative cooling to be effective. The padding and wicking surfaces can be treated with antibacterial coating to prevent fungal and bacterial growth. Water can be distributed to the evaporating areas with tubes or membranes onto of the thermal conductors or heat pipes for additional cooling. This patent application incorporates laminated actuators of our filed patent application U.S. Ser. No. 11/702,821, filed Feb. 6, 2007, based on U.S. Provisional Application 60/765,607, filed Feb. 6, 2006 “Laminate Actuators and Valves” as if fully set forth herein as an air and heat flow control mechanism because of their simplicity, unique low mass and structural formability to be incorporated into apparel. PRIOR ART Hockaday Robert, et al. U.S. Pat. No. 6,772,448 B1 “Non-Fogging Goggles” Our patent describes using heat pipes to move body heat to heat the lens of a goggle. This patent describes using a water absorbent on the vents. It does describe using wicking sweat from the body contact but it does not describe using the evaporative cooling on the exterior of the heat pipe to cool the body or using actuated vents to regulate the flow air to achieve regulated body cooling. Pierce Brendan U.S. Pat. No. 7,207,071 “Ventilated helmet system” This is an example of ribbed passageways for air flow in a helmet. This patent describes placing a dust air filter in the incoming air flow. Porous hydrophilic foam in contact with the wearer is described. Wicking with a cloth liner is described. Using the venturi effect and convective effect to draw air is described. He describes a need for metering the air flow, but does not show a method of doing this besides the passive air flow effects. Golde Paul U.S. Pat. No. 7,017,191“Ventilated protective garment” is an example of a ventilated garment using air flow passageways and aerodynamic ventilation of the garment. Uses an air permeable panel and a ventilation slit that can be opened and closed. This patent does describe the need to able to change the ventilation and cooling with changing environment around motorcycle riders wearing helmets and leather riding suits. This patent does not describe auto actuation on humidity or temperature of the open and closing of the ventilation slit. VanDerWoude Brian et al. US Patent application 20070028372“Medical/surgical personal protection system providing ventilation, illumination and communication” is an example of a helmet for medical personal ventilation with a sterile barrier around medical personnel. It uses a ventilation fan. This patent does not describe auto actuation on humidity or temperature control of the ventilation system, but does provide fan flow volume control with electronic control button controls. Arnold Anthony Peter US Patent 20050193742 “Personal heat control device and method” is a personal cooling of protective head gear. They use heat pipes in the foam pads. Thermoelectric on garments is the primary claim. This patent application does not use air flow for cooling or describe evaporative cooling coupled with the heat pipes. Barbut Denise et al. US patent applications 20070123813 and 20060276552 “Methods and devices for non-invasive cerebral cooling and systemic cooling” Describes heat pipes that are used to cerebral cooling with heat pipes inserted into the nasal cavity. They also describe using a pump to move evaporating cooling fluids into the lumens cavities inside the body. This patent application does not describe using auto actuation with humidity or temperature to control the cooling. Simon-Toy Moshe et al. US patent application 20010003907 “Personal Cooling Apparatus and Method” Uses thermal conductors, such as graphite fibers, in contact with living body, uses wicking of sweat, antimicrobial coatings, and incorporates automatic integrated thermostat control of air flow device. It does mention a variety of air flow mechanisms fans, and convective air flow. This patent application does not use auto actuation bi-material laminate actuator valves or heat pipes. Angus June, et al. US patent application 20020134809 “Waist Pouch” Uses moisture heat and air flow channels, wicking to evaporative cooling remote from the site of the sweating. This patent application does not use heat pipes, or auto actuation laminate actuated valves to control air flow. Gupta Ramesh, et al. US patent application 20070204974 “Heat pipe with controlled fluid charge” is a heat pipe system that uses a controlled amount of mass working fluid to control the upper temperature limit on heat pipes heat transfer at high temperatures. This patent application does not integrate the heat pipe into apparel or animal contact. Turner David, et al. US Patent application 20030045918 “Apparel Ventilation System” David Turner uses pressurized air flow in channels in helmets and apparel to achieve cooling. This patent application used a pressurized bladder and a plurality of air flow channels and openings in wearer contact in apparel for ventilation. Providing sufficient air ventilation for wearer's body to regulate their temperature. This patent application does describe using the perspiration of the user combined with air flow as a body's natural cooling mechanism. It also describes wicking perspiration away. This patent application describes using compressed warm or cool air as the air flow source. This patent application does not describe an auto thermal or humidity actuated air flow control system. McCarter Walter K., et al. US Patent application 20050246826 “Cooling Garment for Use with a Bullet Proof Vest” This patent application teaches using air ribbed air flow channels under armor. Excessive sweating of wearer can lead to discomfort, skin irritation and dehydration. This device uses a detachable fan to move air flow. This patent application describes using water resistant surface coatings. This patent application does not describe an auto thermal or humidity actuated air flow control system. Touzov; Igor Victorovich US patent application 20070151121 “Stretchable and transformable planar heat pipe for apparel and footwear, and production method thereof” This patent describes a stretchable heat pipe made of polymers and rubbers used inside shoes and apparel. It uses the effect of boiling point set by the atmospheric pressure surrounding the heat pipe, thereby reducing the transfer of heat when the body contact is bellow the boiling point of the heat pipe. This invention describes using the heat pipe in conjunction with socks and the heat pipe extending out of the apparel into the atmosphere. This heat pipe system does not describe using the wicking covering on the heat pipe and evaporative cooling on the heat pipe outer surfaces or using humidity or thermal or humidity auto actuated valve to control air flow or cooling of the heat pipe. Clodic Denis WO/1997/006396 PCT/FR96/01270 “Footwear or clothing article with integral thermal regulation element” This patent describes a heat pipe that moves heat from relatively warm regions of the body to cooler regions of the body and the exterior atmosphere. It does describe an air circulating channel supplies forces air flow underneath the heat pipe. This patent application does not describe using auto thermal or humidity actuated air flow control system. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 Cross Sectional View of Heat Removal System for Helmet 1 . Air into helmet channels 2 . Helmet 3 . Air flow channels in the padding and heat pipe 4 . Heat pipe with fluid 5 . Layer that expands with humidity 6 . Substrate layer of the actuator that can bend 7 . Condensation and heat delivery area of the heat pipe 8 . Air flow over the exterior of the heat pipe and helmet 9 . Laminate actuator 10 . Air flow exiting the helmet 11 . Laminate actuator 12 . Heat pipe and wick out of the rim of the helmet 13 . Head of the wearer 14 . Wicking material covering the heat pipe 15 . Hole in helmet 16 . Thermal expansion layer actuating flap valve 17 . Substrate layer bending 18 . Aperture with air flowing through 19 . Air Space FIG. 2 Wick Covered Heat Pipe 20 . Sweat from body and skin of wearer 21 . Evaporation and wicking of sweat and water 22 . Boiling of working fluid of heat pipe 23 . Wicking onto surface of heat pipe 24 . Heat pipe wall, impermeable to the working fluid 25 . Wicking material inside heat pipe 26 . Condensing working fluid inside heat pipe 27 . Working liquid fluid inside the heat pipe 28 . Body and skin of wearer FIG. 3 Actuated Vents with Heat Pipe 35 . Sweat wicking off wearer 36 . Inlet moisture absorbent 37 . Inlet air flow 38 . Helmet, shell, armor or apparel exterior 39 . Working fluid bubble 40 . Condensed Working fluid 41 . Wicking material or cloth exterior of heat pipe in thermal contact 42 . Sweat or water on exterior of heat pipe 43 . Airflow exit aperture 44 . Air flowing out of exit aperture 45 . Humidity or temperature expansion layer of the laminate actuator 46 . Substrate layer of the laminate actuator 47 . Working fluid of the heat pipe 48 . Inner wicking material or cloth inside the heat pipe 49 . Wall of heat pipe 50 . Sweat of wearers skin 51 . body of wearer 52 . Fan or air pump 53 . Exterior cooling fins on dehydrator 54 . Biocide coating or particles (anti bacterial or anti fungus material) 55 . Airflow channel FIG. 4 Actuated Air Flow with Thermally Conductive Wicking Padding 60 . Fan 61 . Moisture absorbent 62 . Airflow thru the absorbent and air flow into the channels of the padding 63 . Helmet, armor, apparel, or structure wall. 64 . Sweat 65 . Exit of apertures 66 . Exit air flow 67 . Expansion laminate material 68 . Substrate laminate material 69 . Thermally conductive padding in helmet 70 . Wicking material or fabric 71 . Sweat on body 72 . Body 73 . Sweat wicking onto exterior wick of pads 74 . Cooling fins of de-hydrator 75 . Biocide coating or particles 76 . Channels in padding 77 . Network filter or electrostatic filter FIG. 5 Actuated Air Flow Cooling System With Supplemental Water Distribution and Body Contact Layer. 90 . Heat fins on dehydrator 91 . Absorbent beads 92 . Filter network or electrostatic filter electret fins or sheets 93 . Air flow 94 . Shell of armor 95 . Evaporating water or wick on thermal conductive padding 96 . Air flow channel 97 . Water wick pore or diffusion pore 98 . Vapor diffusion route or pore 99 . Supplemental water 100 . Exit air flow aperture 101 . Exit air flow 102 . Expansion or contraction layer of actuator 103 . Substrate film of actuator 104 . Membrane water permeable, or impermeable, fabric layer, or garment 105 . Biocide treatment or salt or water vapor reducing film 106 . Thermally conductive padding 107 . Sweat from human on wearer side of layer 108 . Sweat on wearer 109 . Water on thermally conductive padding side of layer 110 . Wearer 111 . Water on thermal conductive padding side of membrane or fabric layer 112 . Fan. 113 . Wicking material on thermal conductor 114 . Tubing 130 . Pump and bladder 131 . Supplemental cooling fluid FIG. 6 Laminate Actuator Valve 115 . Shelf in aperture 116 . Aperture 117 . Expansion layer 118 . Notch in actuator 119 . Actuating flap 120 . Second actuating flap 121 . Substrate layer 122 . Expansion or contraction layer 123 . Cut in laminate 124 . Cut in laminate 125 . Cut in laminate DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Several typical embodiments of the invention are illustrated in the following frames. In these drawings several variations in assembly and arrangements will be shown. Please note that the drawings are drawn disproportionately to illustrate the physical features of this invention. In FIG. 1 a cross sectional view of helmet on a human head is shown. In a typical application the protective shell or helmet 2 is made of Kevlar and polyester resin lamination or steel. The padding 4 on the head of the human 13 is open cell urethane or closed cell neopream foam with a silk covering over the urethane foam. Inside the padding are flexible or rigid heat pipes. Rigid heat pipes 4 can be formed out of stainless steel or copper and the working fluid can be water, butane, or fluorocarbons such as perfluorhexane, 2-methyl perfluorpentane 1,1 difluroethane, 1,1,1,2-tetrafluroethane. Flexible heat pipes 4 , 7 , 12 can be formed out of aluminum foil sandwiched between polyester and polypropylene laminate, which typically are used to encapsulate lithium ion batteries. The working fluid in the flexible heat pipe 4 , 7 , 12 is chosen to have a boiling point at atmospheric pressure since the flexible heat pipe will be at a pressure of the surrounding atmosphere due to the flexible walls and ability to change volume, at comfortable temperature such as 28° C. of pentane. An example of a non-combustible and non-toxic working fluid is trichloromonofluomethane (Freon 11) with a boiling point of 23.8° C. The amount of working fluid in the flexible heat pipe 4 , 7 , 12 is determined precisely as to not have an excess amount such that the heat pipe will inflate to its maximum extent and not burst the seals when the heat pipe is heated above its boiling point. The choice of working fluid can be mixtures of different fluids that are aziotropes that achieve a desirable boiling point such as 5% water and pentane with a boiling point of 34.6° C. By establishing a heat pipe 4 , 7 , 12 boiling point with an impurity gas or though the pressurization via the flexible walls of the heat pipe the heat removal will only occur above the boiling point of the working fluid. This prevents the heat pipe from removing heat bellow the boiling point, so that it acts like an automatic thermostat and does not remove heat when the wearer surface 14 is cold. The heat pipes can be formed into a network to cover the head and extend out into the exterior air 7 , 12 , either through the helmet via 15 a vent hole or around the rim of the helmet shown in FIG. 1 . The heat pipes will be filled with the working fluid and a wicking material 4 to redistribute the liquid working fluid by capillary action back to the heat source. These wicking materials can be silk or finely woven stainless steel mesh. In some situations such as in a helmet the wicking material inside the heat pipe 4 can be deleted if the helmet 2 or application is oriented in gravity such that the liquid return of the working fluid is back down to the heat source (the head 13 ). This can lead to a beneficial situation that if the outside air 8 , is hotter than the human 13 there will be no liquid on the high area of the heat pipe 7 and it will be able to boil fluid and transfer heat from the outside environment to the inside the helmet 3 , 14 . This can be very important to not transfer heat into the human 13 , such as when there is fire on the outside of the helmet 2 or armor. To control the airflow 1 through the helmet laminate actuators 5 , 6 , 9 , 11 are made of two layers such as a polyester substrate film 6 which has a low to negative thermal expansion coefficient and the temperature or humidity expanding material layer 5 such as Nylon (Wright Coating Co., 1603 North Pitcher St., Kalamazoo, Mich. 49007), Nafion (Sigma-Aldrich Co., 3050 Spruce St., St Louis, Mo., 63103) or an aromatic polyetherketone resin having protonic acid group (US Patent application 20040191602 Mitsu Corporation, 580-32 Nagaura, Sodegaura-City, Chiba 299-0265, Japan), for expansion with high humidity or polyethylene for expansion with high temperatures. The laminate actuators 5 , 6 , 9 , 11 can be placed such that they block the airflow out 10 of the exit apertures 15 when the interior of the helmet is low humidity or cold. When the humidity rises or the temperatures rise the apertures open 5 , 6 , 9 , 11 . With the apertures open air flows 1 , 10 through channels 3 formed in the wick covered padding 4 , 14 and evaporation of sweat or water added to the padding in the helmet. Air flowing 1 over the exterior of the heat pipes cools the heat pipes and removed heat from the surface 14 of the wearer 13 . To draw air out though the vent 15 in the top of the helmet 2 a venturi flow 10 constriction and hole 15 can be formed with the heat pipe 7 or a vent cover 16 , 17 . The high velocity flow causes the pressure to be lowered and draw air out of the top of the helmet 2 . Other arrangements such as with motorcycle helmets is to direct the vent cover open such that face away from the air flow 8 direction as illustrated vent 16 , 17 and draw air through the aperture 18 the actuator 16 , 17 when opened. To moderate or control the cooling of the heat pipe that is outside the helmet a laminated actuator cover or variable insulation layer 16 , 17 can be placed over the heat pipe 7 . This laminate actuator layer or layers 16 , 17 can react to temperature alone, in contrast to the laminate actuators 5 , 6 , 9 , 11 on the inside of the helmet or body armor that react to humidity or temperature. These exterior laminated actuators, as an example, are made with a lamination of polyester substrate layer 17 with a low coefficient of thermal expansion and a polyethylene layer 16 with a high thermal expansion coefficient. The laminate actuator sheet 16 , 17 , fibers, or polymorphic surface are cut to form flap valves or random hair like actuation. Flap actuators 16 , 17 and apertures 18 can be formed to close and block air flow through the aperture 18 . In both cases the laminate actuators interfere with flow of air and flow over heat from the heat pipe 7 . These thermal actuated laminate actuators 16 , 17 placed on the outside of the helmet or armor 2 can be a fabric like material that expands and traps air 19 when exterior temperatures or low and allows air flow 18 when temperatures are high. Thermally conductive materials such as graphite sheets, fibers, copper wires, copper foils, aluminum wires, or aluminum oxide can be incorporated into the padding foam 4 , 14 or substituted for the heat pipes 7 to move heat away from the wearer to the water evaporating areas or outside the helmet 2 . The thermally conductive materials or rigid heat pipes 12 exposed to the outside air flow 8 have the disadvantage that if they are taken to the outside the helmet can remove or add heat to the wearer, but are simple to construct compared to the heat pipes. To correct this disadvantage a laminate actuator cover 16 , 17 , as shown covering the heat pipe on the top of the helmet 7 , can thermally insulate the heat pipe 7 when temperatures are low. In operation of the helmet air flows 1 into the channels of the padding 14 , 4 of the helmet removing some heat through the padding by heating up the incoming air, if the outside air is cooler than the wearer. Additional cooling occurs from the evaporation of sweat which is wicked 14 through silk or COOL MAX® (Intex Corporation, 1031 Summit Ave. Greensboro, N.C. 27405) onto the surface of the padded heat pipes into the air flow channels 3 . The air flow 1 is blocked by the laminate actuators 5 , 6 , 9 , 11 if the humidity or temperatures are low in the helmet 2 . If the humidity or temperatures are high the laminate actuators 5 , 6 , 9 , 11 open and air flows 1 and evaporative cooling occurs and heat is removed from the surface of the wearer 14 via the heat pipes of thermally conductive pads 4 . The moisture laden air flow exits 10 from the helmet though vent holes 15 or out though the back rim valves 11 of the helmet 2 . Air flow movement is expected to be driven by thermal convention or forced by the motion of the wearer on a motorcycle or vehicle. Later drawings will show how the air flow can be forced through the padding channels with a fan or pump. In FIG. 2 a cross sectional view of the wick covered heat pipe is shown in contact with a wearer's skin or body. In this diagram the heat pipe 24 , 25 , 22 , 26 , 27 draws sweat 20 off the surface of the wearer 28 where the heat pipe makes contact with the wearer's skin. The sweat 21 wicks over the surface of the heat pipe through the silk covering of the heat pipe 23 . On the surfaces of the heat pipe that is exposed to flowing air the sweat 21 evaporates and the cools the surface of the heat pipe. Inside the heat pipe the working fluid condenses 26 and delivers heat through the heat of condensation of the working fluid 27 . While on the contact area with the wearer 28 the working fluid liquid boils 22 and removes heat from the surface of the wearer 28 via the heat of vaporization. Heat can also be removed from the surface of the wearer 28 through the heat pipe to the cooler surroundings without evaporating sweat 21 off the surface of heat pipe. The heat pipe walls 24 are formed by heat sealing an aluminum layer or copper layer lined polyester polyethylene sandwich material (Vendor address). An inner wicking liner 25 is placed inside the heat pipe such as silk fabric, polyester fabric, open cell urethane foam, or fine woven stainless steel mesh. In FIG. 3 a wick covered heat pipe inside a helmet or armor shell with air flow and actuating valve are shown. In this example the heat pipe 49 is part of the padding of the helmet or armor 38 and is pressed against the wearer 51 . Sweat 50 from the wearer 51 is wicked from the surface of the skin 35 and through the wicking fabric 41 of covering the heat pipe 49 . The sweat 42 wicks to the surfaces of the heat pipe/padding 41 to be exposed to the air flow channels 55 in the helmet 39 . The air flows 37 through an air intake and out 44 through a vent port 43 . In this example a de-humidifier 53 filled with a material such as zeolite beads or a salt 36 that absorbs water vapor from the air. With this absorption the heat of condensation and heat of interaction is delivered on the zeolite or salt 36 . This heat is then conducted to heat fins 53 and dissipated into the surroundings. A fan or pump 52 can be used to force air flow 37 through the dehumidifier and air flow channels 55 . If the wearer 51 is traveling through the air their may be sufficient rammed air pressure and subsequent air flow 37 through the dehydrator and the air flow channels 55 to cool the wearer 51 . Thus, the fan or pump 52 may not be needed. In situations where the wearer 51 is stationary, the fan or pump 52 may be necessary to achieve sufficient air flow to cool the wearer 51 . A laminate actuator valve 43 , 45 , 46 is shown in this example. It is formed by a lamination of polyester plastic film 46 coated at the bending areas with, Nylon, aromatic polyetherketone resin, or other humidity swelling plastic film 45 . Temperature actuation could be enabled by laminating on the actuator a plastic film 45 such as polyethylene which has a high thermal coefficient of expansion. Both thermal expansion and humidity expansion materials could be laminated onto the actuator substrate film 46 to produce temperature and humidity actuation with changes in temperature and humidity. The laminate actuator 45 , 46 covers its aperture 43 when humidity or temperatures are low and uncovers the aperture 43 when humidity or temperatures are high. This allows air to flow 37 though the air channels in the padding 55 and out 44 through the vent hole 43 . This in turn allows sweat 42 to evaporate and cool the surface of the heat pipe 41 , 49 and the heat pipe 49 in turn cools the surface of the wearer 51 , by boiling a working fluid 47 . A working fluid 47 , such as pentane is wicked onto the inner surfaces of the heat pipe 49 with a silk or polyester liner fabric 48 . The working fluid 47 boils 39 , removing heat, at the thermal contact of the wearer 51 , and then deliverers' heat by condensation 40 to the sweat 42 in the wick cover 41 on the heat pipe 49 when it condenses 40 . Then as the air is flows 37 , 44 past the water wicked surface 42 on the outer surface of the heat pipe 49 heat is removed by vaporization of the sweat 42 . A biocide such as silver coatings or photoreactive titanium dioxide particles or films 54 are deposited into and onto the wicking fabric 41 on the heat pipe 49 . The biocide 54 is added to block the growth of bacteria or fungus on the wicking surfaces 41 because they are moist and may be impregnated with dead skin, body fluids, and sweats from the wearer 51 and provide ideal growth environment for bacteria and funguses. In FIG. 4 wick covered thermally conductive padding dehydrating air flow and laminate actuator are shown. In this example the padding 69 on the wearer 72 is thermally conductive and a conduit for heat flux such as radiant heat transfer, fluid circulation (convection), electron conduction (metals), and phonon heat transfer (electrical insulators). The thermal conduit padding 69 can be open cell urethane foam loaded with graphite, aluminum oxide, or copper powder, closed cell silicone rubber, closed cell neopreame rubber, closed cell polystyrene foam, or closed cell urethane rubber foam. The padding 69 can also be a bladder filled with a, powder, beads, liquid, or jelly such as silicone gel Beta Gel (Geltec Corporation, Ltd, Shinagawa TS Bldg. 2-13-40 Konan Minato-ku, Tokyo 108-0075, Japan). Materials such as graphite powder, graphite fibers, carbon nano-tubes, aluminum wires, aluminum fibers, magnesium powder, silver powder, silver wires, copper wires, copper powder, silicon carbide powder, zirconium oxide powder, aluminum oxide powder, and water gels, can be incorporated into the padding 69 to increase the thermal conductivity. The thermal conductive material 69 can act to homogenize the temperature environment contained behind the armor which can be useful when certain parts of the armor are exposed to different temperatures and heat loss environments such as in gloves and shoes, where the finger tips and toes are cold and the palms and ankles may be hot. There are physiological situations where the human or animal body reduces or has reduced blood flow to the extremities and the external redistribution of heat to the extremities can be useful. The padding 69 is covered with a wicking material 70 such as silk fabric or hydrophilic treated polyester fabric such as COOL MAX®. The wicking fabric 70 can be coated with a photo catalytic titanium oxide coating (TPXsol, KON corporation, 91-115 Miyano Yamauch-cho, Kishima-gun Saga prefecture, Japan) 75 to achieve a high surface energy and wet-ability. This wetting coating 70 such as photo catalytic coating can also act as a biocide killing bacteria and fungus on contact. Silver coatings 75 on the wicking material 70 can also be used as a biocide. The air inlet contains loosely packed beads or cadged beads of moisture absorbent material 61 such as a zeolite, silica gel, or calcium oxide that remove moisture from the inlet air as it flows through. This air inlet bed 61 , 77 can also act to filter out insects, dust, rain, snow, bacteria, and dirt from the air flowing into the channels in the padding 76 and incorporate techniques such as network mesh filter such as expanded Teflon and/or electrostatic filter such as parallel sheets of charged electrets of silicone rubber 77 . The dehydration of the air flow 62 may be useful in high humidity environments but may be less useful in environments where the relative humidity is below 50%. The heat of condensation of the moisture and the reaction of the moisture with the moisture absorbent 61 is conducted to the armor walls 63 of the dehydrator and dissipated to the environment through cooling fins 74 . A fan or pump 60 is used to push air through the dehydrator particles 61 and channels 76 in the padding. The fan or pump 60 could be linked to the laminate actuator 67 , 68 to only operate when the laminate actuator valve 65 , 67 , 68 has opened and air will flow through the system. In some situations thermal convection of air flow or just the motion of the wearer may be sufficient to move air through the air channels 76 to effectively cool the wearer 72 . A laminate actuator valve 65 , 67 , 68 is shown in this example formed by a lamination of a polyester or polyimide plastic film 68 coated at the bending areas with Nylon, aromatic polyetherketone resin or other humidity swelling plastic film 67 . Temperature actuation could be enabled by laminating onto the substrate film 68 an actuating plastic film 67 such as polyethylene which has a high thermal coefficient of expansion. Both thermal expansion and humidity expansion materials could be laminated onto the substrate film 68 to produce temperature and humidity actuation with changes in temperature and humidity. The laminate actuator 67 , 68 covers the opening 65 when humidity or temperatures are low and uncovers the opening 65 when humidity or temperatures are high. This allows airflow 62 , 66 though the channels 76 in the padding 69 and out through the vent hole 65 . This air flow allows sweat 64 to evaporate and diffuse water molecules into the dry incoming air, and cool the wicking surface 70 of the thermally conductive pads 69 which in turn cools the surface of the wearer 72 . Sweat 71 from the body 72 is wicked through the cloth cover 70 to the outer surfaces 64 of the thermal conductor 69 . When the temperatures or humidity inside the helmet 63 is low the laminate actuator valve 65 , 67 , 68 closes and air flow 66 is blocked or impeded. This air flow blockage or impedance reduces the heat flux lost from evaporation, diffusion, and convection and maintains comfortable conditions inside the helmet 63 . In FIG. 5 the cooling system with supplemental water supply for evaporation and a fabric or membrane layer between the wearer and the thermal conductor is shown. In this embodiment of the invention the features of the wicking material 113 on thermally conductive padding 106 is shown. A humidity or temperature activated laminate actuator valve 102 , 103 are shown covering an exit aperture 100 in the armor shell 94 . An air flow intake fan 112 with dehydrator beads bed 91 and conduction and convection cooling fins 90 on the exterior of the dehydrator is shown. In certain situations supplemental evaporative cooling may be very desirable for this invention. These are situations where the cooling needs tax the wear to sweat sufficiently or the wearer needs to be isolated from the external air such as in hazardous environmental suits. Thus, to provide this higher cooling capacity evaporative cooling water can be distributed onto the wick 113 on the thermally conductive padding 106 through tubes such as polyurethane (Stevens Urathane, 412 Main Street, Easthampton, Mass. 01027) or silicone rubber tubing 114 (Silicone Specialty Fabricators, 222 Industrial Park Drive, Elk Rapids, Mich. 49629). A network of tubing with open exits or tubes with small pores, 98 , 97 can distribute water to the wicking material 113 on the thermal conductors 106 in the air flow passages 96 . Other alternative methods of delivering the supplemental water is through a water permeable membrane such a thin walled polyurethane tubing 114 or though a hydrophobic porous water vapor permeable membrane of expanded Teflon or GORE-TEX® (W.L. Gore & Associates, Inc., 295 Blue Ball Road, Elkton, Md. 21921). In all three cases the water distribution system tubes 114 should be in physical contact or thermal contact with the thermal conductive padding 106 to be able to conduct heat from the wearer 110 to the evaporative cooling sites 95 . These supplemental fluid tubes 114 could also be sealed tubes or a portion being sealed and the chilled fluid or heated fluid 124 circulated throughout the helmet or body armor 94 . A pump 123 , such as a hand squeeze elastic bladder, could be used to circulate or oscillator the fluids into the tubes 114 . Another configuration that will be used in many situations is that the wearer 110 has a wicking fabric 104 covering their skin such as silk or micro fiber polyester COOL MAX® and the sweat route 108 , 107 , 109 , 111 and thermal contact must go through this fabric covering. This layer interface between the wick covered thermal conductor 113 , 106 and the wearer 110 may also be a membrane 104 such as polyurethane or silicone rubber membrane to allow water 107 , 109 to diffuse through but not allow bacteria or viruses through. This membrane 104 could be a porous hydrophobic liquid water blocking membrane that would allow vapor through while not allowing liquid water to flow through such as with expanded Teflon, or GORE-TEX® fabric. The membrane 104 could also be an impermeable barrier such as neoprene rubber or stainless steel plate where only heat removal is desired. When the water transport 108 , 107 , 109 , 111 from the wearer 110 to the wick covered thermal conductor 106 , 113 , 95 is done with a selectively permeable membrane 104 such as an cellulose nitrate, osmotic membrane (Membrane Process Engineering, 3-3-3 Akasaka, Minato-Ku, Tokyo, Japan) or a vapor transport membrane such as expanded Teflon a salt or water vapor pressure reducing material such as sodium chloride, cotton, titanium dioxide, or Nafion polymer electrolytes 105 can be coated or incorporated into the wicking material on the thermally conductive padding 106 . This creates a vapor pressure gradient, surface tension energy gradient, with the higher surface tension energy on the evaporation sites 95 , or ionic concentration gradient to draw water from the wearer to the wicking covering material 113 . This can keep the wearer's surface 110 dry and comfortable. In operation the supplemental water 99 distribution 97 , 98 from the tubes 114 and wicking materials 113 could be provided for on demand or thorough sensors built into the laminate actuators 102 , 103 that sense excessive temperatures. The fan 112 can also be activated through the same laminate actuator sensor 102 , 103 . When temperatures are low the laminate actuator could cover the aperture 100 and stop the evaporative cooling 95 , 98 and the fan 112 would shut off to thermally insulate and conserve heat of the wearer 110 . In operation air is drawn through the water absorbent 9 and electrostatic filter 92 with a fan 112 . This insures that the air flow 93 is dry and clean. The airflow 93 through the channel between the conductive pads 106 and armor 94 . Evaporation of water occurs on the surface of the wick 113 and the supplemental fluid tubes 98 . If the temperatures are high the laminate actuators 102 , 103 will open and let the exit air flow 101 through the aperture 100 . In FIG. 6 a sample of sheet of laminate actuator valves is shown. The constructions of these laminate actuators are formed out of two or more films of materials 121 , 122 that have different expansion properties and are laminated together. The different expansion properties of the two films 121 , 122 lead to shear stress between the two films. To relieve this stress laminated films will curl once they find a preferential curl or non-constrained direction. If the laminate sheet is cut into patterns such as the three right angle cuts 123 , 124 , 125 as shown in FIG. 6 the laminate will curl into a flap arrangement 117 , 119 , 120 that has a preferential fold determined by the geometry of the cut pattern and the laminated material deposits. The aperture 116 left by the cut can act as the aperture of a valve when the flap presses back into the aperture 116 . A shelf 115 can be cut or formed into the substrate 121 and the flap 118 such that the flap can only open one direction and creates a seal with the aperture 116 when the actuation goes in the opposite curl direction. An example of a laminate actuator construction is to thermally bond a 25 micron thick sheet of polyester 121 with a low thermal expansion coefficient to a 75 micron thick sheet of polyethylene 122 with a high coefficient of expansion. In this particular example the flaps or actuators 119 , 120 would curl open when hot and curl closed when cooled to press the notch on the flap 118 to the shelf 115 on the aperture 116 . Laminated actuator structures can be cut with many patterns such as two right angle cuts, three angles cuts that form flaps and apertures. Laminate actuators can be formed and cut on two or three dimensional surfaces such as fibers, cylinders and polymorphic surfaces. Our patent Application U.S. 60/765,607 describes a host of cut patterns, geometries of laminate actuator valves. These valves are auto-actuating valves and auto-changing structures that change with changes in temperature, relative humidity, chemical, electrical, and light environments. Mesh support materials or shelves 115 can be laminated onto the apertures 116 to create screens as flap stops to prevent the flap from curling through the aperture and opening in the opposite direction. These laminated actuator valves and structures can range in size from many centimeters nanometer dimension hairs. The actuators can be effective as hairs that actuate and created impedance to fluid and thermal flow or fluff layers of actuators to effectively increase thermal insulation by pushing each layer apart to create stagnant cavities of fluid (gasses or liquids). The laminate actuated structures can also include coiling and uncoiling fibers and strips. Another construction example of a laminate actuator is to form the laminated layers with a porous polyester substrate or polyethylene 121 and a temperature or humidity expanding material layer 122 such as Nylon, Nafion, or an aromatic polyetherketone resin having protonic acid group for expansion. The porosity of the substrate 121 can enhance the adhesion between the layers and also increase the sensitivity to moisture by allowing diffusion through the substrate membrane 121 to the expanding material layer 122 . The expanding material layer 122 is coated onto the one side of the polyester substrate 121 . Specific deposit patterns and thicknesses of the expanding layer 122 can be used to efficiently utilize the expansion polymers and create effective actuation patterns. Additional layers of coatings and electrodes such as piezoelectric materials can be deposited on the substrate 121 or expansion layers 122 such as a piezoelectric material of polydifluoethylene (PDVF), and electrodes such as vapor deposited platinum films, or sliver print. These additional coatings can provide for functions to act as sensors to the relative humidity, temperature, or be electrically stimulated to open the actuators or cause them to oscillate and pump air flow. Physical elements of this invention include: 1. Wick contact with living body 2. Heat pipe or thermal conductor or conduit in contact with living body 3. Air flow in channels 4. Evaporative cooling in the air flow channels and on heat pipes or thermal conductors. 5. Using flexible or elastic heat pipes pressure equilibrium with the external atmosphere to set the boiling point of the working fluid. 6. Using impurities in the heat pipe working fluid to set the boiling point of the working fluid inside the heat pipes. 7. Heat pipes without wicks and gravity orientation to act as one way heat delivery systems and avoid heat flow back to the wearer. 8. Humidity or temperature auto-reactive laminate actuator structures and/or valves to control air flow to try and achieve more constant temperature or humidity conditions, by impeding air flow when dry or cold and reducing impedance when humid or hot. 9. Humidity or temperature auto-reactive laminated actuator structures to achieve self adjusting variable thermal insulation to achieve more constant temperature by increasing thermal resistance when dry or cold and decrease thermal resistance when humid or hot. 10. Covering the living body padding with a plurality of reactive laminate actuator valve arrays or actuated structures such as curling hairs. 11. Covering the exterior of the helmet or body armor to achieved self adjusting variable thermal insulation. 12. Delivering extra liquid water or a fluid for evaporative cooling inside the helmet or armor to the wicking padding on the thermal conductors or heat pipes. 13. Fluid flow systems that can also be used to deliver hot or cold fluids to the inside the helmet or armor. 14. Delivering liquid water and evaporation through a membrane for cooling inside the helmet or armor. 15. Coating the wicking materials with biocides and fungicides. 16. Using a fan or pump to push air flow or fluid flow through the channels in the helmet or body armor. 17. Using a moisture absorbent to remove moisture from the air entering the helmet or body armor. 18. Using a filter and/or electrostatic filter to remove contaminants from the air flowing into the helmet or body armor. 19. Using a wicking covering over the living body. 20. Using a selectively permeable membrane between the living body and the air flow passages. 21. Using ionic concentration gradients to draw water away from the living body surface. 22. Using surface tension gradients to draw water away from the living body surface. 23. Using the position and geometry of air flow vents with respect to the helmet or body armor air flow environment or gravity orientation to achieve high air flow rates and convective air flow rates in the channels in the helmet or body armor. 24. Using a pump to move supplemental fluids into the helmet or body armor to for supplemental evaporative cooling or circulating cooled or heated fluids. While this invention has been described with reference to specific embodiments, modifications, and variations of the invention may be constructed without departing from the scope of the invention.

The lack of air flow under body armor, helmets, and thick garments can lead to excessive moisture build up and discomfort on the wearers body due to lack of heat removal and effective evaporation of sweat. By incorporating wick covered heat pipes or thermal conductors with air flow channels in the apparel contact area between the garments, helmets, and body armor the effectiveness air flow cooling and evaporation of sweat can be restored. Humidity or temperature auto-actuated bi-material valves are used to control this air-moisture-heat flow to achieve a controlled comfortable humidity-temperature environment and avoid excessive cooling. Supplementary air pumps, filters, dehydrators, fluid pumps, heating fluids, and cooling fluids may be incorporated to enhance the effectiveness. Biocides and hydrophilic materials are also incorporated on the wick coverings to avoid biological growth and maintain performance to achieve a healthy environment for the wearer.

DETAILED DESCRIPTION The present invention relates to new 1-(disubstituted phenoxy)-3-amino-2-hydroxypropane derivatives, to their preparation and therapeutic use in cerebrovascular disorders and to pharmaceutical compositions adapted to that use. A number of phenol ethers of 3-amino-2-hydroxypropane, in which the amino group is substituted by alkyl, such as isopropyl or t-butyl, or by phenyl alkyl are known. Pharmacologically, compounds of this type block the adrenergic β-receptors in various organs and some are used therapeutically. (Ehrhart/Ruschig, Arzneimittel, 2nd Ed., 1971, Vol. 2, page 179 and DOS 2,021,101). Derivatives of benzhydrylamine have been available commercially as antihistamines for a relatively long time. (Ehrhart/Ruschig, 10C, Cit., Vol. 1, page 314). The present invention pertains to 1-(disubstituted phenoxy)-3-amino-2-hydroxypropanes of the formula: ##STR1## in which EACH OF R and R', individually, is alkyl, alkenyl, alkoxy, carbalkoxy or chloro and R" is diphenylmethyl or fluorenyl. The invention also pertains to the acid addition salts thereof, and to condensation products thereof with aldehydes, ketones and carbonic acid. In a first embodiment, the invention pertains to compounds selected from the group consisting of (a) 1-(disubstituted phenoxy)-2-hydroxypropylamine derivatives of Formula I wherein R is lower alkyl, lower alkenyl, lower alkoxy, carbo(lower alkoxy), or chloro; R' is lower alkyl, lower alkenyl, lower alkoxy, carbo(lower alkoxy), or chloro; and R" is diphenylmethyl or fluoren-9-yl; (b) the pharmaceutically acceptable acid addition salts thereof and (c) the cyclic condensation products thereof with carbonic acid or an aldehyde or ketone. A further embodiment pertains to such cyclic condensation products with an aldehyde or ketone wherein the products have the formula: ##STR2## in which R, R' and R" are as defined above and X is lower alkylidene or phenyl(lower alkylidene). A further embodiment pertains to such cyclic condensation products with carbonic acid which products have the formula: ##STR3## wherein R, R' and R" are as defined above. A further embodiment of the present invention pertains to compounds of the formula: ##STR4## wherein each of R and R' is selected from the group consisting of alkyl of 1 to 6 carbon atoms; alkenyl of 2 to 7 carbon atoms; alkoxy of 1 to 6 carbon atoms, carbalkoxy of 2 to 7 carbon atoms, or chloro; and Q and Q', when taken independently, are each hydrogen or, when taken together, are a carbon-carbon bond, and to the pharmaceutically acceptable acid addition salts thereof. A further embodiment pertains to compounds wherein each of R and R', independently of the other, is alkyl of 1 to 3 carbon atoms, alkenyl of 3 carbon atoms, alkoxy of 1 to 3 carbon atoms, carbomethoxy, carbethoxy or chloro. A further embodiment pertains to compounds wherein each of R and R', independently of the other, is methyl, ethyl, propyl, allyl, propenyl, methoxy, ethoxy, carbomethoxy, carbethoxy or chloro. A further embodiment pertains to compounds wherein R is 2-methoxy or 2-ethoxy and R' is n-propyl, allyl or propenyl in 4- or 5-position. A further embodiment pertains to compounds wherein each of R and R' are chloro in 2- and 4-, 2- and 5-, or 3- and 4-positions. The term lower alkyl denotes a univalent saturated branched or straight hydrocarbon chain containing from 1 to 6 carbon atoms. Representative of such lower alkyl groups are thus methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, and the like. The term lower alkenyl denotes a univalent branched or straight hydrocarbon chain containing from 2 to 6 carbon atoms and nonterminal ethylenic unsaturation as, for example, vinyl, allyl, propenyl isopropenyl, 2-butenyl, 3-methyl-2-butenyl, 2-pentenyl, 3-pentenyl, 2-hexenyl, 4-hexenyl, and the like. The term lower alkoxy denotes a straight or branched hydrocarbon chain of 1 to 6 carbon atoms bound to the remainder of the molecule through a divalent oxygen atom as, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy and hexoxy. The new 1-(disubstituted phenoxy)-3-amino-2-hydroxypropanes of the present invention and their condensation products with aldehydes, ketones or carbonic acid are obtained by several processes. (a) Compounds of the formula: ##STR5## in which R and R' are as defined above, Y is hydroxy and Z is a reactive ester, or Y and Z together are an epoxy group are allowed to react with diphenylmethylamine or fluorenylamine (or a condensation product thereof with an aldehyde or ketone of the formula: R"--N=X in which R" and X are as defined above). By a reactive ester is intended a group derived from a hydroxy group by reaction with a strong inorganic or organic acid, in particular a hydrogen halide acid such as hydrochloric acid, hydrobromic acid or hydriodic acid, in which case Z is chloro, bromo or iodo, and sulfuric acid, or a strong aliphatic or aromatic sulfonic acid, for example methanesulfonic acid, benzenesulfonic acid, 4-bromobenzenesulfonic acid or 4-toluenesulfonic acid. (b) An amine of the formula: ##STR6## in which R and R' are as defined above, is allowed to react with a compound of the formula Z--R" in which Z and R" are as defined above. In lieu of the amine of Formula IV a condensation product thereof with an aldehyde or ketone of the formula: ##STR7## in which R, R' and X are as defined above or the corresponding condensation product with carbonic acid, of the formula: ##STR8## in which R and R' are as defined above, can be used. (c) A disubstituted phenol of the formula: ##STR9## in which R and R' are as defined above is allowed to react with a compound of the formula: ##STR10## in which R", Y and Z are as defined above or with the corresponding condensation product thereof with an aldehyde or ketone of the formula: ##STR11## in which R", X and Z are defined above, or with a corresponding condensation product with carbonic acid of the formula: ##STR12## in which R" and Z are as defined above. (d) A compound of Formula I, in which R, R' and R" have the above meanings, but which carries a removable protecting group on either or both of the nitrogen atom of the 3-amino group and on the 2-hydroxy group, is appropriately treated to remove this group. The compounds thus prepared can be converted in the customary manner into their physiologically tolerated acid addition salts. Suitable acids are, for example, hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, methanesulfonic acid, acetic acid, lactic acid, succinic acid, maleic acid, fumaric acid, malic and tartaric acid. The condensation products of the compounds are those with aldehydes and ketones, preferably with alkanals with up to 4 carbon atoms, particularly formaldehyde, or also with phenyl alkanals, particularly benzaldehyde (so that X is lower alkylidene or phenyl lower alkylidene), and those with carbonic acid. The compounds which are not condensed with aldehydes ketones or carbonic acid are preferred as therapeutic groups. Protecting groups which are removable are those which can be split off by solvolysis, in particular by hydrolysis or ammonolysis. Those which can be split off by hydrolysis are, for example, acyl radicals, including functionally modified carboxyl groups, as for example oxycarbonyl groups, such as alkoxycarbonyl groups, e.g., the tert.-butoxycarbonyl or ethoxycarbonyl; aralkoxycarbonyl groups, such as phenyl lower alkoxycarbonyl radicals, e.g., carbobenzoxy and halogenocarbonyl groups such as chlorocarbonyl; arylsulphonyl groups, such as the toluenesulphonyl or bromobenzenesulphonyl group, lower alkanoyl groups, optionally halogenated as with fluorine such as formyl, acetyl or trifluoroacetyl; benzoyl; cyano; silyl groups, such as trimethylsilyl; and an acetal group. For the hydroxy group, the oxycarbonyl; lower alkanoyl; and benzoyl groups are preferred. For the amino group, ylidene groups can also be employed, as for example an alkylidene, benzylidene or phosphorylidene group, such as the triphenylphosphorylidene group, in which case the nitrogen atom then carries a positive charge. In addition both the amino and hydroxy group can be protected. In addition to the condensation products already disclosed, a compound of the formula: ##STR13## wherein R, R' and R" are as defined above, can thus be hydrolyzed to yield the free hydroxy aminopropanes. Groups which can be split off by ammonolysis include, in particular, the halogenocarbonyl function, such as chlorocarbonyl. If, in process embodiment (1), (2-ethoxy-5-propenylphenoxymethyl)-oxirane, or, in process embodiment a(2), 1-(2-ethoxy-5-propenylphenoxy)-2-hydroxy-3-chloropropane, and fluorenylamine are selected as typical starting materials, the reaction can be represented as follows: ##STR14## If, in process embodiment b), 1-(2-methoxy-4-allylphenoxy)-2-hydroxy-3-aminopropane and diphenylmethyl bromide are selected as typical starting materials, the reaction can be diagrammatically represented as follows: ##STR15## If, in process embodiment c(1), 1-chloro-2-hydroxy-3-diphenylmethylaminopropane, or, in process embodiment c(2), 2-methoxy-4-n-propylphenol diphenylaminomethyloxirane, and in both cases 2-methoxy-4-n-propylphenol are selected as typical starting materials, the reaction can be diagrammatically represented as follows: ##STR16## If, in process embodiment c(3), 2-methoxy-4-n-propylphenol and 3-diphenylmethyl-5-chloromethyloxazolidine are selected as typical starting materials, the reaction can be diagrammatically represented as follows: ##STR17## If, in process embodiment d), 1-(3,4-dichlorophenoxy)-2-hydroxy-3-(N-acetyldiphenylmethylamino)propane is selected as a typical starting material, the reaction can e diagrammatically represented as follows: ##STR18## Alternatively in process embodiment d), if 1-(2-ethoxy-5-propenylphenoxy)-2-(tetrahydropyran-2-yloxy)-3-diphenylmethylaminopropane is selected as a representative starting material, the reaction can be diagrammatically represented as follows: ##STR19## Finally in process embodiment d), if 3-diphenylmethyl-5-(2,4-dichlorophenoxymethyl)-oxazolidin-2-one is selected as the starting material, the reaction can be diagrammatically represented as follows: ##STR20## Some of the disubstituted phenol ethers of Formula III are known. Those which are new can be obtained by conventional techniques. Compounds of Formula III in which Y and Z form an epoxy group can thus be obtained by reacting the correspondingly disubstituted phenols of Formula VI with epichlorohydrin in the presence of at least molar amounts of a basic condensing agent. Disubstituted phenol ethers of Formula III in which Y is a hydroxy group and Z is a reactive ester group, such as for example chlorine, can be obtained from corresponding epoxides of Formula III by reaction with the appropriate acid, as for example hydrochloric acid. Disubstituted phenols of Formula VI also can be reacted with epichlorohydrin in the presence of catalytic amounts of a base, such as for example piperidine. Typical starting materials of Formula III: (2-methyl-3-chlorophenoxymethyl)-oxirane, (2-methoxy-4-propyl-phenoxymethyl)-oxirane, (2-methoxy-4-allyl-phenoxymethyl)-oxirane,(2-methoxy-4-cis- and -4-trans-propenyl-phenoxymethyl)-oxirane, (2 -carbethoxy-4-methoxy-phenoxymethyl)-oxirane, (2-carbethoxy-4-ethoxy-phenoxymethyl)-oxirane, (2,4-dichloro-phenoxymethyl)-oxirane, (2-ethoxy-4-carbethoxy-phenoxymethyl)-oxirane, (2-methoxy-4-carbomethoxy-phenoxymethyl)-oxirane, (2-methoxy-4-chloro-phenoxymethyl)-oxirane, (2-ethoxy-4-chloro-phenoxymethyl)-oxirane, (2-allyl-4-methoxy-phenoxymethyl)-oxirane, (2-allyl-4-chloro-phenoxymethyl)-oxirane, (2-chloro-4-ethoxyphenoxymethyl)-oxirane, (2-ethoxy-5-propyl-phenoxymethyl)-oxirane, (2-methoxy-cis- and -5-trans-propenyl-phenoxymethyl)-oxirane, (2-ethoxy-5-cis- and -5-trans-propenylphenoxymethyl)-oxirane, (2,5-dichloro-phenoxymethyl)-oxirane, (2,5-diethoxy-phenoxymethyl)-oxirane, (2-methoxy-5-carbethoxy-phenoxymethyl)-oxirane, (2-ethoxy-5-carbethoxyphenoxymethyl)-oxirane, (2-carbethoxy-5-methoxy-phenoxymethyl)-oxirane, (2-methoxy-5-chloro-phenoxymethyl)-oxirane, (2-ethoxy-5-chloro-phenyoxymethyl)-oxirane, (2-chloro-5-ethoxy-phenoxymethyl)-oxirane, (2,6-dimethyl-phenoxymethyl)-oxirane, (2-chloro-6-allyl-phenoxymethyl)-oxirane, (2-methoxy-6-allyl-phenoxymethyl)-oxirane, (2-ethoxy-6-allyl-phenoxymethyl)-oxirane, (2-methyl-6-chloro-phenoxymethyl)-oxirane, (2,6-dimethoxy-phenoxymethyl)-oxirane, (3,4-dichlorophenoxymethyl)-oxirane, (3,4-dimethoxy-phenoxymethyl)-oxirane, (3-chloro-4-methoxy-phenoxymethyl)-oxirane, (3-ethoxy-4-chloro-phenoxymethyl)-oxirane, (3-methyl-5-ethyl-phenoxymethyl)-oxirane, 1-(2-methyl-3-chloro-phenoxy)-2-hydroxy-3-chloropropane, 1(2-methoxy-4-propyl-phenoxy)-2-hydroxy-3-bromopropane, 1-(2-methoxy-4-allyl-phenoxy)-2-hydroxy-3-chloropropane, 1-(2-methoxy-4-cis- and -4-trans-propenylphenoxy)-2-hydroxy-3-chloropropane, 1-(2-carbethoxy-4-methoxy-phenoxy)-2-hydroxy-3-bromopropane, 1-(2-carbethoxy-4-ethoxy-phenoxy)-2-hydroxy-3-bromopropane, 1-(2,4-dichlorophenoxy)-2-hydroxy-3-iodopropane, 1-(2-ethoxy-4-carbethoxyphenoxy)-2-hydroxy-3-chloropropane, 1-(2-methoxy-4-carbomethoxy-phenoxy)-2-hydroxy-3-chloropropane, 1-(2-methoxy-4-chloro-phenoxy)-2-hydroxy-3-chloropropane, 1-(2-ethoxy-4-chloro-phenoxy)-2-hydroxy-3-methanesulphonyloxypropane, 1-(2-allyl-4-methoxy-phenoxy)-2-hydroxy-3-benzenesulphonyloxypropane, 1-(2-allyl-4-chloro-phenoxy)-2-hydroxy-3-chloropropane, 1-(2-chloro-4-ethoxy-phenoxy)-2-hydroxy-3-toluenesulphonyloxy-propane, 1-(2-ethoxy-5-propyl-phenoxy)-2-hydroxy-3-iodopropane, 1-(2-methoxy-5-cis- and -5-trans-propenylphenoxy)-2-hydroxy-3-iodopropane, 1-(2 -ethoxy-5-cis- and -5-trans-propenyl-phenoxy)-2-hydroxy-3-bromopropane, 1-(2,5-dichloro-phenoxy)-2-hydroxy-3-chloropropane, 1-(2,5-diethoxyphenoxy)-2-hydroxy-3-chloropropane, 1-(2-methoxy-5-carbethoxyphenoxy)-2-hydroxy-3-chloropropane, 1-(2-ethoxy-5-carbethoxyphenoxy)-2-hydroxy-3-bromopropane, 1-(2-carbethoxy-5-methoxyphenoxy)- 2-hydroxy-3-chloropropane, 1-(2-methoxy-5-chlorophenoxy)-2-hydroxy-3-chloropropane, 1-(2-ethoxy-5-chlorophenoxy)-2-hydroxy-3-bromopropane, 1-(2-chloro-5-ethoxyphenoxy)-2-hydroxy-3-bromopropane, 1-(2,6-dimethyl-phenoxy)-2-hydroxy-3-iodopropane, 1-(2-chloro-6-allyl-phenoxy)-2-hydroxy-3-chloropropane, 1-(2-methoxy-6-allyl-phenoxy)-2-hydroxy-3-chloropropane, 1-(2-ethoxy-6-allyl-phenoxy)-2-hydroxy-3-methanesulfulphonyloxypropane, 1-(2-methyl-6-chlorophenoxy)-2-hydroxy-3-benzenesulphonyloxypropane, 1-(2,6-dimethyl-phenoxy)-2-hydroxy-3-chloropropane, 1-(3,4-dichlorophenoxy)-2-hydroxy-3-toluenesulphonyloxypropane, 1-(3,4-dimethoxy-phenoxy)-2-hydroxy-3-iodopropane, 1-(3-chloro-4-methoxy-phenoxy)-2-hydroxy-3-bromopropane, 1-(3-ethoxy-4-chloro-phenoxy)-2-hydroxy-3-chloro-propane and 1-(3-methyl-5-ethyl-phenoxy)-2-hydroxy-3-chloro-propane. Many of the amines of Formula IV are known. Those which are not can be readily obtained, in a simple manner, by reacting corresponding epoxides of Formula III with ammonia in an autoclave. Typical of the starting materials of Formula IV include: 1-(2-methyl-3-chloro-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-methoxy-4-propyl-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-methoxy-4-allyl-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-methoxy-4-cis- and -4-trans-propenyl-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-carbethoxy-4-methoxy-phenoxy)- 2-hydroxy-3-aminopropane, 1-(2-carbethoxy-4-ethoxy-phenoxy)-2-hydroxy-3-aminopropane, 1-(2,4-dichloro-phenoxy)-2-hydroxy-aminopropane, 1-(2-ethoxy-4-carbethoxy-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-methoxy-4-carbomethoxyphenoxy)-2-hydroxy-3-aminopropane, 1-(2-methoxy-4-chlorophenoxy)-2-hydroxy-3-aminopropane, 1-(2-ethoxy-4-chlorophenoxy)-2-hydroxy-3-aminopropane, 1-(2-allyl-4-methoxyphenoxy)-2-hydroxy-3-aminopropane, 1-(2-allyl-4-chlorophenoxy)-2-hydroxy-3-aminopropane, 1-(2-chloro-4-ethoxyphenoxy)-2-hydroxy-3-aminopropane, 1-(2-ethoxy-5-propylphenoxy)-2-hydroxy-3-aminopropane, 1-(2-methoxy-5-cis- and -5-trans-propenyl-phenoxy)-2 -hydroxy-3-aminopropane, 1-(2-ethoxy-5-cis- and -5-trans-propenyl-phenoxy)-2-hydroxy-3-aminopropane, 1-(2,5-dichloro-phenoxy)-2-hydroxy-3-aminopropane, 1-(2,5-diethoxy-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-methoxy-5-carbethoxy-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-ethoxy-5-carbethoxy-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-carbethoxy-5-methoxy-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-methoxy-5-chloro-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-ethoxy-5-chloro-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-chloro-5-ethoxy-phenoxy)-2-hydroxy-3-amino-propane, 1-(2,6-dimethyl-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-chloro-6-allyl-phenoxy)-2-hydroxy-3-aminopropane, 1-(2-methoxy-6-allyl-phenoxy)-2-hydroxy-3aminopropane, 1-(2-ethoxy-6-allyl phenoxy)-2-hydroxy-3-aminopropane, 1-(2-methyl-6-chlorophenoxy)-2-hydroxy-3-aminopropane, 1-(2,6-dimethoxyphenoxy)-2-hydroxy-3-aminopropane, 1-(3,4-dichloro-phenoxy)-2-hydroxy-3-aminopropane, 1-(3,4-dimethoxy-phenoxy)-2-hydroxy-3-aminopropane, 1-(3-chloro-4-methoxy-phenoxy)-2-hydroxy-3-aminopropane, 1-(3-ethoxy-4-chloro-phenoxy-2-hydroxy-3-aminopropane and 1-( 3-methyl-5-ethyl-phenoxy)-2-hydroxy-3-aminopropane. Likewise the amines of Formula VII are known in many cases or can be prepared according to known processes. Compounds of Formula VII in which Y is hydroxy and Z is a reactive ester, for example chloro, can be obtained by the reaction of diphenylmethylamine or fluorenylamine with epichlorohydrin. Hydrogen chloride can be eliminated from these new 1-chloro-2-hydroxy-3-diphenylmethylamino- [or -9-fluorenylamino)-] propanes in a known manner by means of strong base to yield diphenylmethylaminomethyl- and 9-fluorenylaminomethyloxiranes. Generally these need not be isolated but can be further processed as crude products. The compounds in which hydroxy and/or amino are protected result from the customary process modification in which a desired protective group(s) is introduced at a preliminary stage of the synthesis of starting materials for utilized process embodiments a through c. Typical of such protected compounds are 1-(2-methoxy-4-propyl-phenoxy)-2-tetrahydropyran-2-yloxy)-3-diphenylmethyl-aminopropane, 1-(2-methoxy-4-propyl-phenoxy)-2-acetoxy-3-diphenylmethylaminopropane, N-acetyl-3-(2-methoxy-4-propyl-phenoxy)-2-hydroxy-1-diphenylmethylaminopropane, 2-phenyl-3-diphenylmethyl-5-(2-methoxy-4-propyl-phenoxy-methyl)-oxazolidine, 3-diphenylmethyl-5-(2-methoxy-4-propyl-phenoxy-methyl)-oxazolidin-2-one, 1-(2-methoxy-4-allyl-phenoxy)-2-(tetrahydropyran-2-yloxy)-3-diphenylaminopropane, 1-(2-methoxy-4-allyl-phenoxy)-2-propionyloxy-3-diphenylmethylaminopropane, N-acetyl-1-(2-methoxy-4-allyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane, 2-methyl-3-diphenyl-methyl-5-(2-methoxy-4-allyl-phenoxy-methyl)-oxazolidine, 3-diphenylmethyl-5-(2-methoxy-4-allyl-phenoxy-methyl)-oxazolidin-2-one, 1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-(tetrahydropyran-2-yloxy)-3-diphenylmethylaminopropane, 1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-(tetrahydropyran-2-yloxy)-3-(9-fluorenylamino)-propane, 1-(2-ethoxy-5-transpropenyl-phenoxy)-2-acetoxy-3-diphenylmethylaminopropane, 1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-propionyloxy-3-(9-fluorenylamino)-propane, N-acetyl-1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane, N-acetyl-1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane, 2-methyl-3-diphenylmethyl-5-(2-ethoxy-5-trans-propenyl-phenoxy-methyl)-oxazolidine, 2-methyl-3-(9-fluorenyl)-5-(2-ethoxy-5-trans-propenyl-phenoxymethyl)-oxazolidine, 2-phenyl-3-diphenyl-methyl-5-(2-ethoxy-5-trans-propenyl-phenoxy-methyl)-oxazolidine, 2-phenyl-3-(9-fluorenyl)-5-(2-ethoxy-5-trans-propenyl-phenoxy-methyl)-oxazolidine, 3-diphenylmethyl-5-(2-ethoxy-5-trans-propenylphenoxymethyl)-oxazolidin-2-one, 3-(9-fluorenyl)-5-(2-ethoxy-5-trans-propenyl-phenoxymethyl)-oxazolidin-2-one, 3-(3,4-dichloro-phenoxy)-2-(tetrahydropyran-2-yloxy)-1-diphenylmethylaminopropane, 3-(3,4-dichloro-phenoxy)-2-acetoxy-1-diphenylmethylaminopropane, N-acetyl-3-(3,4-dichloro-phenoxy)-2-hydroxy-1-diphenylmethylaminopropane, 2-phenyl-3-diphenylmethyl-5-(3,4-dichloro-phenoxymethyl)-oxazolidine and 3-diphenyl-methyl-5-(3,4-dichloro-phenoxymethyl)-oxazolidin-2-one. In process embodiment a(1), generally molar amounts of the reactants are allowed to react in a diluent. Diluents which can be used are all inert organic solvents, as for example, hydrocarbons such as ligroin and toluene, ethers such as diethyl ether, glycol dimethyl ether and dioxane; alcohols such as methanol, ethanol and isopropanol; glycol monomethyl ether and halogenated hydrocarbons such as chloroform, methylene chloride and the like. The reaction temperatures can be varied within a relatively wide range generally from 20° C to 120° C and preferably from 60° C to 100° C. The reaction can be carried out under elevated pressure, but preferably is carried out under normal pressure. When the reaction has ended, the solution is concentrated in vacuo, preferably to about half of its volume. In some cases, the free base will crystallize from the concentrated reaction solution upon cooling. If not, the solution is rendered acidic to Congo Red with ethereal hydrochloric acid, the sparingly soluble hydrochloride salt crystallizing out and being further purified by recrystallization. Process embodiments a(2), b and c(3) are carried out in substantially the same fashion, however in the presence of a basic condensing agent, as for example alkali metal hydroxides, such as sodium hydroxide or potassium hydroxide, alkali metal carbonates, such as potassium carbonate, and alkali metal alcoholates, such as sodium methylate, potassium ethylate and potassium tert.-butylate. The reaction is carried out at a temperature of from 60° C to 200° C especially from 100° C to 130° C, and preferably under such pressure that, depending on the boiling point of the diluent used, the preferred reaction temperature is reached. When the reaction has ended, the inorganic salts are removed by filtration and the resulting amines collected as described above. In process embodiment c(1), again molar amounts of the reactants are employed in a diluent, here however in the presence of an acid-binding agent. The diluents include those discussed above, particularly hydrocarbons, ethers, alcohols, glycol monomethyl ether and ketones such as acetone, methyl isobutyl ketone and cyclohexanone. The acid-binding agents are the customary agents of this type such as alkali metal alcoholates such as sodium methylate and sodium ethylate; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; and alkali metal carbonates such as sodium carbonate and potassium carbonate. The reaction is carried out at a temperature of from 30° C to 200° C and preferably from 50° C to 100° C. Again the reaction can be carried out under elevated pressure but is preferably carried out under normal pressure. After the reaction has ended, the insoluble inorganic salts are filtered off and the reaction solution is concentrated as discussed above. In process embodiment c(2), molar amounts of the reactants are preferably reacted directly. A diluent can be used, as discussed above, but the reaction is generally conducted without a diluent. The reaction temperatures will range from 50° C to 150° C, preferably from 70° C to 120° C, preferably under normal pressure. When the reaction is complete, the reaction mixture is dissolved, if necessary, in a suitable diluent and the product collected as discussed above. Hydrolysis of protecting groups in process embodiment d) utilizes either acid agents such as dilute mineral acids or basic agents such as of alkali metal hydroxides. Oxycarbonyl, arylsulphonyl and cyano groups are generally split off with the aid of acidic agents such as a hydrogen halide acid, appropriately hydrobromic acid and preferably dilute hydrobromic acid optionally mixed with acetic acid. Cyano groups are preferably split off with hydrobromic acid at elevated temperature, such as in boiling hydrobromic acid (the Braun bromocyano method). A tert.-butoxycarbonyl group can be removed under anhydrous conditions by treatment with a suitable acid such as trifluoroacetic acid. Ammonolysis is effected in the customary manner, such as for example, with an amine which contains at least one hydrogen atom bonded to the nitrogen atom, such as with a mono- or di-(lower alkyl)amine, as for example, methylamine or dimethylamine, or in particular with ammonia, and is preferably effected at elevated temperature. In place of ammonia, it is also possible to use an agent which releases ammonia, such as hexamethylenetetramine. Depending on the choice of the starting materials and the procedures, the new compounds can be in the form of enantiomers or racemates or, if they contain at least two centres of chirality, in the form of mixtures of diastereomeric racemates. In those cases in which the new compounds contain an alkenyl with different substituents about the double bond, it is also possible for geometric isomers, or their mixtures, to exist. Mixtures of diastereomeric racemates and of geometric isomers can be resolved into the two pure diastereomeric racemates or, respectively, separated into the cis- and trans-isomers in a known manner on the basis of the physico-chemical differences between the constituents, for example by chromatography and/or fractional crystallization. Resulting racemates can be resolved into the enantiomers by known methods, for example by recrystallization from an optically active solvent, with the aid of micro-organisms or by reaction with an optically active acid which forms salts with the racemic compound and separation of the diastereomers obtained in this way, for example on the basis of their different solubilities. The enantiomers are then liberated from the diastereomers by conventional methods. Optically active acids which are particularly commonly used are, for example, the D- and L- forms of tartaric acid, di-o-toluyltartaric acid, malic acid, mandeli acid, camphorsulfonic acid and quinic acid. The compounds according to the invention increase the mental functional capacity, the cerebral blood flow and the resistance of the brain to transitory total ischaemia. They are therefore indicated in the case of reduced intellectual functional capacity with age and for trauma and especially for the prophylaxis and therapy of apoplectic shocks. There is thus provided a method of combatting the above-mentioned conditions in humans and other animals, by which a compound of the invention, alone or in admixture, is administered perorally, parenterally (for example intramuscularly, intraperitoneally or intravenously) or rectally, preferably parenterally and especially intravenously. In general, significant effects are observed upon administering the compounds in amounts of from about 0.1 to about 10.0 mg/kg, preferably 0.5 to 5.0 mg/kg, of body weight every 24 hours. Optionally this is in the form of several individual administrations, in order to achieve the desired results. An individual administration can for example contain from about 0.05 to about 5.0 mg/kg, and especially 0.1 to 1.0 mg/kg, of body weight. However, the dose must be titrated to the condition and response and it may be necessary to depart from the precise dosages mentioned and in particular to do so as a function of the age, nature and body weight of the patient, the nature and the severity of the condition, the formulation, the route of administration, and frequency of administration, in all cases utilizing sound professional judgment. Compared with currently available cerebral therapeutic agents such as pemoline, bencyclan, vincamine, cinnarizin, piracetam and xanthinol niacinate, the compounds of the invention display a considerably stronger and longer-lasting activity. Surprisingly, the new substances do not display any blocking or stimulating action on the adrenergic β-receptors of the various organs, nor do they have any antihistaminic action. These pharmacological actions can be conveniently observed in recognized animal models of which the following are representative for a number of typical compounds. In the representative data which follow, the compounds of the invention are abbreviated as follows: 1-(2-ethoxy-5-trans-propenylphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride of Example 1 is "compound A"; 1-(2-methoxy-4-allylphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride of Example 4 is "compound B"; 1-(2-ethoxy-5-trans-propenylphenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane of Example 28 is "compound C" and 1-(3,4-dichlorophenoxy)-2-hydroxy-3-diphenylmethylaminopropane of Example 26 is "compound D." In addition, the following commercially available products were included for purposes of comparison: 1-isopropylamino-3-(1-naphthyloxy)-2-propanol (= propanolol) as β-blocking agent, and bencyclan, 1-cinnamyl-4-diphenylmethylpiperazin (= cinnarizin) and vincamine as cerebral therapeutic agents. 1. Protective action against amnesia in male mice Method A modification of the method of Taber and Banuazizi (Psychopharmacol. 9, 382-91, 1966) was employed. Mice are taught to remain seated in a small compartment of a test cage and not to move into the larger compartment in which an electric shock to the foot were previously received. If a convulsive electric shock is applied to a mouse after it has been so taught, it develops amnesia and forgets the previous experience (the shock to its foot in the larger compartment), and moves from the smaller compartment into the larger compartment. By pre-treating the animals with a test substance, it is possible to determine whether these substances have any protective action against the amnesia produced. Each test substance is administered to the particular animal 3 times at intervals of 24 hours, the last administration being 1 hour before the first test. Two groups are formed for each test; a control group with amnesia and a pre-treated group. For each test group, the average value of the times which have elapsed befoe the barrier is crossed on the 2nd day is calculated. This time is taken as a criterion for the learning capacity. The results of the experiments are illustrated graphically in the accompanying drawings in which Fig. 1: shows the protective action of compound A against amnesia induced by electric shock in male mice; Fig. 2: shows the protective action of compound B against amnesia induced by electric shock in male mice; Fig. 3: shows the protective action of compound D against amnesia induced by electric shock in male mice; Fig. 4: shows the protective action of propranolol against amnesia induced by electric shock in male mice; and Fig 5: shows the protective action of vincamine against amnesia induced by electric shock in male mice. As can be seen from FIGS. 1-5, compounds A, B and D according to the invention are considerably more effective against amnesia induced by elctric shock in mice than the comparison substances propanolol and vincamine. 2. Increase in the cerebral blood flow in cats and dogs Method Cats (1.8-3.0 kg) and dogs (18-25 kg) of both sexes are rendered analgetic with fentanyl and curarized. The specific blood flow through the grey and white brain matter is determined with the aid of the clearance curve for 133 xenon. Table 1______________________________________administration (cats) Dose Increase in the cerebral blood flowSubstance mg/kg by %______________________________________Compound A 2.5 40Compound B 10 48Compound C 2.5 28Compound D 2.5 77Bencyclan 10 30Cinnarizin 5 30Vincamine 8 27______________________________________ Table 2______________________________________Oral administration (cats) Dose Increase in the cerebral blood flowSubstance mg/kg by %______________________________________Compound A 50 12Compound B 50 10Compound C 25 30Compound D 50 44Bencyclan up to φ 50Cinnarizin up to φ 100______________________________________ Results for compound A and bencyclan are graphically depicted in FIGS. 6A, 6B and 7. As can be seen from Tables 1 and 2 and FIGS. 6A, 6B and 7, compounds A, B, C and D in this test significantly increase the cerebral blood flow in cats and dogs. On intravenous administration, their action at lower doses is stronger than that of the comparison substances. On peroral administration to cats, bencyclan and cinnarizin are inactive at 50 and 100 mg/kg respectively, while compounds A, B, C and D display a distinct action at 50 and 25 mg/kg. 3. Restricted circulation and mortality after a transient total cerebral ischaemia ("experimental apoplexy") Method A 7-minute complete cerebral ischaemia is caused in curarized cats by inflating a collar placed around the neck. The blood flow (measured by 133 xenon clearance), initially increses when the cerebral circulatory system is opened again but falls within a few minutes to far below the initial vale and does not reach this value again, even after hours. For cats which have not been pre-treated, the 7-minute cerebral ischaemia is fatal, 94% of all the control animals dying within 48 hours. The compounds according to the invention however have a significant protective action against this non-reflow phenomenon. In the case of cats which were pretreated with compound A (50 mg/kg perorally), no restriction in the cerebral blood flow occurs after a 7-minute cerebral ischaemia. Only 33% of the cats pretreated with compound A died, the difference being significant at p > 0.01. The compounds not only increase the blood supply in a healthy brain but have a distinct prophylactic and therapeutic action in an extreme experimental apoplexy. The comparison substances, vincamine and cinnarizin, ae inactive in this test. General pharmacology and toxicology of these compounds can be summarized as follows. At a concentration of about 10 -1 mg/ml, the compounds have a positive inotropic action on an isolaed guinea-pig atrium. The compounds however are not β-sympathomimetic agents since this action is not eliminated by β-blocking agents. A β-sympatholytic action can also be excluded since the β-sympathomimetic action of isoproterenol is not influenced by the compounds. Since the spasm caused in an isolated intestine by histamine is not specifically inhibited, the compounds do not have antihistamine action. Typical values for acute toxicity (LD 50 ) in mice are as follows: Table 3______________________________________ LD.sub.50 (mg/kg)Compound Intravenously Orally______________________________________A 80 >2,000B 43 450C 85 >2,000D 76 >2,000propranolol 30 220bencyclan 33 >2,000cinnarizin 27 >2,000vincamine 95 460______________________________________ The compounds of the present invention are administered parenterally or orally in any of the usual pharmaceutical forms. These include solid and liquid oral unit dosage forms such as tablets, capsules, powders, suspensions, solutions, syrups and the like, including sustained release preparations, and fluid injectable forms such as sterile solutions and suspensions. The term unit dosage form as used in this specification and the claims refer to physically discrete units to be administered in single or multiple dosage to animals, each unit containing a predetermined quantity of active material in association with the required diluent, carrier or vehicle. The quantity of active material is that calculated to produce the desired therapeutic effect upon administration of one or more of such units. Powders are prepared by comminuting the compound to a suitable fine size and mixing with a similarly comminuted diluent pharmaceutical carrier such as an edible carbohydrate material as for example, starch. Sweetening, flavoring, preservative, dispersing and coloring agents can also be present. Capsules are made by preparing a powder mixture as described above and filling formed gelatin sheaths. A lubricant such as talc, magnesium stearate and calcium stearate can be added to the powder mixture as an adjuvant before the filling operation; a glidant such as colloidal silica may be added to improve flow properties; a disintegrating or solubilizing agent may be added to improve the availability of the medicament when the capsule is ingested. Tablets are made by preparing a powder mixture, granulating or slugging, adding a lubricant and disintegrant and pressing into tablets. A powder mixture is prepared by mixing the compound, suitably comminuted, with a diluent or base such as starch, sucrose, kaolin, dicalcium phosphate and the like. The powder mixture can be granulated by wetting with a binder such as syrup, starch paste, acacia mucilage or solutions of cellulosic or polymeric materials and forcing through a screen. As an alterantive to granulating, the powder mixture can be run through the tablet machine and the resulting imperfectly formed slugs broken into granules. The granules can be lubricated to prevent sticking to the tablet forming dies by means of the addition of stearic acid, a stearate salt, talc or mineral oil. The lubricated mixture is then compressed into tablets. The medicaments can also be combined with free flowing inert carriers and compressed into tablets directly without going through the granulating or slugging steps. A protective coating consisting of a sealing coat of shellac, a coating of sugar or polymeric material and a polish coating of wax can be provided. Dyestuffs can be added to these coatings to distinguish different unit dosages. Oral fluids such as syrups and elixirs can be prepared in unit dosage form so that a given quantity, e.g., a teaspoonful, contains a predetermined amount of the compound. Syrups can be prepared by dissolving the compound in a suitably flavored aqueous sucrose solution while elixirs are prepared through the use of a non-toxic alcoholic vehicle. Suspensions can be formulated by dispersing the compound in a non-toxic vehicle in which it is insolbule. Fluid unit dosage forms for parenteral administration can be prepared by suspending or dissolving a measured amount of the compound in a non-toxic liquid vehicle suitable for injection such as an aqueous or oleaginous medium and sterilizing the suspension or solution. Alternatively a measured amount of the compound is placed in a vial and the vial and its contents are sterilized and sealed. An accompanying vial or vehicle can be provided for mixing prior to administration. Suppositories can be formulated from the usual water-soluble or water-insoluble diluents, such as polyethylene glycols and fats, e.g. cocoa oil and high esters such as those of C 14 -alcohol with C 16 -fatty acid or mixtures of these diluents. For parenteral administration, the solutions and emulsions will be course be sterile, and, if appropriate, blood-isotonic. All the pharmaceutical compositions according to the invention can also contain coloring agents and preservatives as well as perfumes and flavoring additions (e.g. peppermint oil and eucalyptus oil) and sweentening agents (e.g. saccharin). They will generally contain from 0. to 99.5%, more usually from 0.5 to 95%, of the active ingredient by weight of the total composition. In addition to a compound of the invention, the compositions can contain other pharmaceutically active compounds, as well as a plurality of compounds of this invention. The examples which follow will serve to further illustrate the inventionn without being a limitation on the scope thereof. The temperatures are given in degrees Celsius. EXAMPLE 1 (process a,l) ##STR21## 117 g of (2-ethoxy-5-trans-propenyl-phenoxymethyl)-oxirane are dissolved in 400 ml of isopropanol. After adding 91.5 g of diphenylmethylamine, the mixture is heated for 5 hours under a reflux condenser. After cooling, the resulting reaction solution is concentrated in vacuo to approximately half its original volume and is rendered acid to Congo Red with ethereal hydrochloric acid. After the further addition of dry ether, 166 g (= 73% of theory) of 1-(2-ethoxy-5-transpropenyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride crystallizes out in the form of colorless crystals which, after recrystallization from a methanol/water mixture, melt at 145°-146°. The crystalline base which is obtainable from this product with aqueous ammonia melts, after recrystallization from petroleum ether, at 75°-76°. (2-Ethoxy-5-trans-propenyl-pehnoxymethyl)-oxirane which has a melting point of 68°-69° and is required as the starting material is obtained by reacting 4-propengylguaethol with epichlorohydrin in aqueous potassium hydroxide solution. The compounds which follow are prepared according to the process of Example 1: EXAMPLE 2 ##STR22## 66.1 g = 79% of theory of 1-(2-methyl-3-chloro-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 39.7g of (2-methyl-3-chloro-phenoxymethyl)-oxirane (boiling point 0 .45 120°-123° C) and 36.6 g of diphenylmethylamine. Colorless crystals with a melting point of 207°-210° (from methanol). EXAMPLE 3 ##STR23## 21.9 g = 82.5% of theory of 1-(2-methoxy-4-n-propylphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 13.3 g of (2-methoxy-4-n-propyl-phenoxymethyl)-oxirane (melting point 41°-43°) and 11 g of diphenylmethylamine. Colorless crystals with a melting poit of 108°-110° C (from ethyl acetate/petroleum ether). EXAMPLE 4 ##STR24## 53.2 g = 80.6% of theory of 1-(2-methoxy-4-allylphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 33.0 g of (2-methoxy-4-allyl-phenoxymethyl)-oxirane (melting point 37°-38.5°) and 27.4 g of diphenylmethylamine. Colorless crystals with a melting point 143° (from methanol/water). EXAMPLE 5 ##STR25## 21 g = 72% of theory of 1-(2-ethoxy-4-carbethoxyphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 16 g of (2-ethoxy-4-carbethoxy-phenoxymethyl)-oxirane (melting point 59°-61°) and 11 g of diphenylmethylamine. Colorless crystals with a melting point of 148°-150° (from isopropanol). EXAMPLE 6 ##STR26## 37.3 g = 75.2% of theory of 1-(2-methoxy-4-carbomethoxyphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 26.4 g of (2-methoxy-4-carbethoxy-phenoxymethyl)-oxirane (melting point 79°-81°) and 19.2 g of diphenylmethylamine. Colorless crystals with a melting point of 143°-146° C (from ethanol/water). EXAMPLE 7 ##STR27## 35 g = 87.4% of theory of 1-(2-methoxy-4-cis-propenylphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 20 g of (2-methoxy-4-cis-propenyl-phenoxymethyl)-oxirane (boiling point 0 .5 148°-152°) and 16.7 g of diphenylmethylamine. Colorless crystals with a melting point of 133°-136°. EXAMPLE 8 ##STR28## 46.7 g = 78% of theory of 1-(2-methoxy-4-trans-propenylphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 30 g of (2-methoxy-4-trans-propenyl-phenoxymethyl)-oxirane (melting point 55°-58°) and 24.9 g of diphenylmethylamine. Colorless crystals with a melting point of 129°-132° (from isopropanol/ether). EXAMPLE 9 ##STR29## 44.2 g = 89% of theory of 1-(2-carbethoxy-4-methoxy-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 26.5 g of (2-carbethoxy-4-methoxy-phenoxymethyl)-oxirane (boiling point 0 .05 169°-170°) and 19.2 g of diphenylmethylamine. Colorless crystals with a melting point of 120°-124°. EXAMPLE 10 ##STR30## 16.4 g = 61.4% of theory of 1-(2-carbethoxy-4-ethoxy-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 14.6 g of (2-carbethoxy-4-ethoxy-phenoxymethyl)-oxirane (boiling point 0 .7 184°-188°) and 10 g of diphenylmethylamine. Colorless crystals with a melting point of 182°-184°. EXAMPLE 11 ##STR31## 29.4 g = 73.1% of theory of 1-(2,4-dichloro-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 21.9g of (2,4-dichloro-phenoxy-methyl)-oxirane (boiling point 0 .1 140°-145°) and 18.3 g of diphenylmethylamine. Colorless crystals with a melting pont of 226°-228°. EXAMPLE 12 ##STR32## 55.1 g = 83.5% of theory of 1-(2-allyl-4-methoxy-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 33 g of (2-allyl-4-methoxy-phenoxymethyl)-oxirane (boiling point 0 .05 117°-122°) and 27.5 g of diphenylmethylamine. Colorless crystals with a melting point of 157°-159°. EXAMPLE 13 ##STR33## 44.7 g = 67% of theory of 1-(2-allyl-4-chloro-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 33.7 g of (2-allyl-4-chloro-phenoxymethyl)-oxirane (boiling point 0 .07 122°-124°) and 27.5 g of diphenylmethylamine. Colorless crystals with a melting point of 157°-158° C (from methanol/water). EXAMPLE 14 ##STR34## 18.8 g = 68.7% of theory of 1-(2-ethoxy-5-n-propylphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 14.2 g of (2-ethoxy-5-n-propyl-phenoxymethyl)-oxirane (boiling point 0 .6 148°-154°, melting point 48°-52°) and 11 g of diphenylmethylamine. Colorless crystals with a melting point of 111°-113° (from isopropanol/ether). EXAMPLE 15 ##STR35## 37.9 g = 86% of theory of 1-(2-methoxy-5-trans-propenylphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 22 g of (2-methoxy-5-trans-propenyl-phenoxymethyl)-oxirane (boiling point 0 .3 146°-151°, melting point 58°-59°) and 18.3g of diphenylmethylamine. Colorless crystals with a melting point of 163°-165° (from ethanol). EXAMPLE 16 ##STR36## 23.5 g = 83% of theory of 1-(2-methoxy-5-carbethoxyphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 15.1 g of (2-methoxy-5-carbethoxy-phenoxymethyl)-oxirane (boiling point 0 .25 160°-167°, melting point 61°-63° from ligroin) and 11 g of diphenylmethylamine. Colorless crystals with a melting point of 175°-177° (from ethanol). EXAMPLE 17 ##STR37## 36.3 g = 74.7% of theory of 1-(2-ethoxy-5-carbethoxyphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 26.6 g of (2-ethoxy-5-carbethoxy-phenoxymethyl)-oxirane (boiling point 0 .6 185°-188°, melting point 40°-43°) and 18.3g of diphenylmethylamine. Colorless crystals with a melting point of 185°-187° from ethanol. EXAMPLE 18 ##STR38## 31.2 g = 69.6% of theory of 1-(2-carbethoxy-5-methoxy-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 24 g of (2-carbethoxy-5-methoxyphenoxymethyl)-oxirane (boiling point 0 .1 165°-172°) and 17.4g of diphenylmethylamine. Colorless crystals with a melting point of 167°-171° (from isopropanol). EXAMPLE 19 ##STR39## 21.5 g = 76.9% of theory of 1-(2,5-dichlorophenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 15.2 g of (2,5-dichloro-phenoxymethyl)-oxirane (boiling point.sub. 0.1 133°-139°, melting point 65°-66° from methanol) and 12.7 g of diphenylmethylamine. Colorless crystals with a melting point of 74°-76.5° (from methanol). EXAMPLE 20 ##STR40## 23 g = 83.7% of theory of 1-(2,5-diethoxy-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 14.3 g of (2,5-diethoxy-phenoxymethyl)-oxirane (boiling point.sub. 0.04 145°-150°, melting point 32°-34°) and 11g of diphenylmethylamine. Coloress crystals with a melting point of 131°-133°. EXAMPLE 21 ##STR41## 48.6 g = 73.6% of theory of 1-(2-methoxy-6-allylphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 33.0 g of (2-methoxy-6-allyl-phenoxymethyl)-oxirane (boiling point 0 .05 114°-121°) and 27.4 g of diphenylmethyl-amine. Colorless crystals with a melting point of 167°-170° (from methanol/water). EXAMPLE 22 ##STR42## 44.8 g = 65.8% of theory of 1-(2-ethoxy-6-allyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 35.1 g of (2-ethoxy-6-allyl-phenoxymethyl)-oxirane (boiling point 0 .08 120°-127°) and 27.5 g of diphenylmethylamine. Colorless crystals with a melting point of 136°-138° (from isopropanol/ether). EXAMPLE 23 ##STR43## 43.5 g = 72.9% of theory of 1-(2,6-dimethyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 26.7 g of (2,6-dimethyl-phenoxymethyl)-oxirane (boiling point 0 .07 90°-94°) and 27.5 g of diphenylmethylamine. Colorless crystals with a melting point of 161°-164° (from isopropanol). EXAMPLE 24 ##STR44## 30 g = 82.8% of theory of 1-(2-methyl-6-chlorophenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 17.1 g of (2-methyl-6-chloro-phenoxymethyl)-oxirane (boiling point 0 .5 104°-113°) and 15.8 g of diphenylmethylamine. Colorless crystals with a melting point of 170°-172° (from methanol/water). EXAMPLE 25 ##STR45## 30.1 g = 68.7% of theory of 1-(2,6-dichloro-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 21.9g of (2,6-dichloro-phenoxymethyl)-oxirane (boiling point 0 .1 142°-148°) and 18.3 g of diphenylmethylamine. Colorless crystals with a melting point of 185°-188° (from methanol/water). EXAMPLE 26 ##STR46## 38.1 g (86.1% of theory) of 1-(3,4-dichloro-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane from 24.1 g of (3,4-dichloro-phenoxymethyl)-oxirane (boiling point 0 .1 145°-150°, melting point 42°-43° from methanol) and 20.1 g of diphenyl-methylamine; the said product crystallizes out as the free base when the reaction solution is evaporated. Colorless crystals with a melting point of 114°-115° (from methanol). EXAMPLE 27 ##STR47## 70.5 g = 85.6% of theory of 1-(3-methyl-5-ethyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 38.4 g of (3-methyl-5-ethyl-phenoxymethyl)-oxirane (boiling point 0 .1 115°-120°) and 36.6 g of diphenylmethylamine. Colorless crystals with a melting point of 142.5°-145.5° (from methanol/water). EXAMPLE 28 ##STR48## 93.4 g (69.1% of theory) of 1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane from 76.2 g of (2-ethoxy-5-trans-propenyl-phenoxymethyl)-oxirane and 59 g of 9-aminofluorene; and said product crystallizes out as the free base when the reaction solution is cooled. Colorless crystals with a melting point of 119°-121° (from isopropanol). EXAMPLE 29 ##STR49## 27.8 g = 69% of theory of 1-(2-methoxy-4-n-propyl-phenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane with a melting point of 85°-88° from 22.2 g of (2-methoxy-4-n-propyl-phenoxy-methyl)-oxirane and 18.1 g of 9-aminofluorene. EXAMPLE 30 ##STR50## 30.3 g = 75.4% of theory of 1-(2-methoxy-4-allyl-phenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane with a melting point of 120°-122° from 22 g (2-methoxy-4-allyl-phenoxymethyl)-oxirane and 18.1 g of 9-aminofluorene. EXAMPLE 31 ##STR51## 35.4 g = 81.1% of theory of 1-(3,4-dichloro-phenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane with a melting point of 156°-159° from 21.9 g of (3,4-dichloro-phenoxymethyl)-oxirane and 18.1 g of 9-aminofluorene. EXAMPLE 32 ##STR52## 34 g = 77.9% of theory of 1-(2,5-dichloro-phenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane with a melting point of 93°-95° from 21.9 g iof (2,5-dichloro-phenoxymethyl)-oxirane and 18.1 g of 9-aminofluorene. EXAMPLE 33 (process a,2) 200 ml of epichlorohydrin and 0.5 ml of piperidine are added to 17.8 g of 4-trans-propenylguaethol and the mixture is then heated to 100° for 10 hours. The excess epichlorohydrin is then distilled off in vacuo and the residue is dissolved in 50 ml of isopropanol. After adding 18.3 g of diphenylmethylamine and 30 g of potassium carbonate, the mixture is heated to 120° in an autoclave for 10 hours. After the reaction has ended, the inorganic salts are filtered off and the resulting reaction solution is rendered acid to Congo Red with ethereal hydrochloric acid. 1-(2-Ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-diphenylaminopropane hydrochloride then crystallizes out; after recrystallization from a methanol/water mixture this melts at 145°-146° and is identical to the product described in Example 1. Yield: 16.3 g = 35.9% of theory of colorless crystals. The compounds which follow are prepared according to the process described in Example 33: EXAMPLE 34 12.4 g = 29.8% of theory of 1-(2-ethoxy-5-propenyl-phenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane from 17.8 g of 4-trans-propenylguaethol, 200 ml of epichlorohydrin, 0.5 g of piperidine and 18.1 g of 9-aminofluorene; the product crystallizes out of the resulting reaction solution in the cold. Colorless crystals with a melting point of 119°-121° which are identical to the produce described in Example 28. EXAMPLE 35 10.9 g = 24.8% of theory of 1-(2-methoxy-4-allyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 16.4 g of eugenol, 200 ml of epichlorohydrin, 0.5 g of piperidine and 18.3 g of diphenylmethylamine. The colorless crystals which have a melting point of 143° are identical to the product described in Example 4. EXAMPLE 36 13.3 g = 30.1% of theory of 1-(2-methoxy-4-n-propyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 16.6 g of 2-methoxy-4-n-propyl-phenol, 200 ml of epichlorohydrin, 0.5 g of piperidine and 18.3 g of diphenylmethylamine. The colorless crystals which have a melting point of 108°-110° are identical to the product described in Example 3. EXAMPLE 37 10.5 g = 26.1% of 1-(3,4-dichloro-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride, in the form of colorless crystals with a melting point of 180°-184°, from 16.3 g of 3,4-dichlorophenol, 200 ml of epichlorohydrin, 0.5 ml of piperidine and 8.3 g of diphenylmethylamine. The free base, which is obtainable from this product and has a melting point of 114°-115°, is identical to the product described in Example 26. EXAMPLE 38 (process b) A solution of 22.2 g of (2-methoxy-4-n-propyl-phenoxy-methyl)-oxirane in 200 ml of isopropanol is saturated with gaseous ammonia and the mixture is then heated to 100° C in an autoclave for 4 hours, the resulting reaction solution is then evaporated to about half its original volume and, after adding 30 g of potassium carbonate and 20.2 g of diphenylmethylchloride, the mixture is heated to 120° for 10 hours. After the inorganic salts have been separated off, the resulting reaction solution is rendered acid to Congo Red with ethereal hydrochloric acid and 16.1 g = 36.4% of theory of 1-(2-methoxy-4-n-propyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride are obtained. The colorless crystals melt at 108°-110° and are identical to the product described in Example 3. The compounds which follow are prepared according to the process described in Example 38: EXAMPLE 39 15.0 g = 34.1% of theory of 1-(2-methoxy-4-allyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 22 g of (2-methoxy-4-allyl-phenoxymethyl)-oxirane, ammonia and 20.2 g of diphenylmethyl chloride. Colorless crystals which have a melting point of 143° and are identical to the product described in Example 4. EXAMPLE 40 19.6 g = 43.1% of theory of 1-(2-ethoxy-5-propenyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 23.4 g of (2-ethoxy-5-trans-propenyl-phenoxymethyl)-oxirane, ammonia and 20.2 g of diphenylmethyl chloride. Colorless crystals which have a melting point of 145°-146° and are identical to the product described in Example 1. EXAMPLE 41 14.9 g = 35.9% of theory of 1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane from 23.4 g of (2-ethoxy-5-trans-propenyl-phenoxymethyl)-oxirane, ammonia and 24.5 g of 9-bromofluorene. The free base is obtained direct if the organic salts are separated off while the mixture is still hot and the product is then allowed to crystallize out in the cold. The colorless crystals melt at 119°-121° and are identical to the product described in Example 28. EXAMPLE 42 14.9 g of 1-(3,4-dichloro-phenoxy)-2-hydroxy-3-dipnenylmethylaminopropane from 21.9 g of (3,4-dichloro-phenoxymethyl)-oxirane, ammonia and 24.7 g of diphenylmethyl bromide; the product is obtained in the form of the free base if the reaction mixture is worked up as in Example 41. Yield: 37% of theory. Colorless crystals which have a melting point of 114°-115° and are identical to the product described in Example 26. EXAMPLE 43 (process c,1) 17.8 g of 4-trans-propenylguaethol and 27.6 g of 3-diphenylmethylamino-2-hydroxy-1-chloropropane (melting point 66°-68°), which is obtained by reacting molar amounts of diphenylmethylamine and epichlorohydrin in isopropanol at 20°, are added to a solution of sodium ethylate prepared from 2.3g of sodium and 100 ml ethanol. The mixture is heated to 100° in an autocalve for 12 hours. The sodium chloride which has precipitated out is then filtered off and, by adding ethereal hydrochloric acid to the filtrate, 18.9 g = 41.6% of theory of 1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride are obtained. The colorless crystals have a melting point of 145°-146° and are identical to the product described in Example 1. The compounds which follow are prepared according to the process described in Example 43: EXAMPLE 44 16.7 g = 37.8% of theory of 1-(2-methoxy-4-n-propyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 16.6 g of 2-methoxy-4-n-propyl-phenol and 27.6 g of 1-diphenylmethylamino-2-hydroxy-3-chloropropane. Colorless crystals which have a melting point of 108°-110° and are identical to the product described in Example 3. EXAMPLE 45 17.1 g = 38.9% of theory of 1-(2-methoxy-4-allyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 16.4 g of eugenol and 27.6 g of 1-diphenylmethylamino-2-hydroxy-3-chloropropane. Colorless crystals which have a melting point of 143° and are identical to the product described in Example 4. EXAMPLE 46 14.1 g (35% of theory) of 1-(3,4-dichloro-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane from 16.3 g of 3,4-dichlorophenol and 27.6 g of 1-diphenylmethylamino-2-hydroxy-3-chloro-propane; the product crystallizes out as the free base when the reaction solution is evaporated. Colorless crystals which have a melting point of 114°-115° and are identical to the product described in Example 26. EXAMPLE 47 2 ml of water are added to a solution of 18.1 g of 9-aminofluorene in 200 ml of methanol and 9.4 g of epichlorohydrin are then added dropwise at room temperature. The mixture is stirred overnight and then evaporated in vacuo at a bath temperature of 40°. The residue is added to a prepared solution of 2.3 g of sodium and 17.8 g of 4-trans-propenyl-guaethol in 100 ml of ethanol. The mixture is heated to 100° in an autoclave for 12 hours. The sodium chloride which has precipitated out is then filtered off and the filtrate is concentrated in vacuo to about half of the original volume. 9.8 g (=23.6% of theory) of 1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-(9-fluorenylamino)propane crystallise out in the cold. Colorless crystals which have a melting point of 119°-121° and are identical to the product described in Example 28. EXAMPLE 48 (process c,2) 27.6 g of 1-diphenylmethylamino-2-hydroxy-3-chloropropane are dissolved in 75 ml of 2 N methanolic sodium hydroxide solution. After the solution has stood at room temperature for one hour, the sodium chloride which has precipitated is filtered off and the filtrate is evaporated in vacuo at a bath temperature which is not above 30°. The oily residue is partitioned, by stirring, between 200 ml of ether and 50 ml of water. The layers are separated and the ethereal layer is washed twice more with, in each case, 50 ml of water and dried with potassium carbonate. After evaporating in vacuo (bath temperature ≦ 30°), 23.1 g of diphenylmethylaminomethyloxirane are obtained as a yellowish oil which is further processed as the crude product, without purification. 17.8g of 4-trans-propenylguaethol are added and the mixture is heated to 100° for 10 hours. The reaction mixture is then dissolved in 50 ml of isopropanol and the solution is acidified with ethereal hydrochloric acid. 22.4 g = 49.5% of theory of 1-(2-ethoxy-5-trans-propenylphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride are obtained. Colorless crystals which have a melting point of 145°-146° and are identical to the product described in Example 1. The compounds which follow are prepared by the same process. EXAMPLE 49 20.1 g = 45.7% of theory of 1-(2-methoxy-4-allylphenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride from 27.6 g of 1-diphenylmethylamino-2-hydroxy-3-chloropropane and 16.4 g of eugenol. Colorless crystals which have a melting point of 143° and are identical to the product described in Example 4. EXAMPLE 50 23.1 g = 52.3% of theory of 1-(2-methoxy-4-n-propylphenoxy)-2-hydoxy-3-diphenylmethylaminopropane hydrochloride from 27.6 g of 1-diphenylmethylamino-2-hydroxy-3-chloropropane and 16.6 g of 2-methoxy-4-n-propyl-phenol. Colorless crystals which have a melting point of 108°-110° and are identical to the product described in Example 3. EXAMPLE 51 17.4 g = 43.2% of theory of 1-(3,4-dichloro-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane from 27.6 g of 1-diphenylmethylamino-2-hydroxy-3-chloropropane and 16.3 g of 3,4-dichlorophenol; the product crystallizes out from the cooled reaction solution in the form of the free base. Colorless crystals which have a melting point of 114°-115° and are identical to the product described in Example 26. EXAMPLE 52 18.1 g of 9-aminofluorene are reacted with epichlorohydrin, following the procedure described in Example 47, to give 1-(9-fluorenylamino)-2-hydroxy-3-chloropropane, from which, without purification, (9-fluorenylaminomethyl)oxirane is obtained with methanolic sodium hydroxide solution, by the procedure described in Example 48. Reaction of this compound with 17.8 g of 4-trans-propenylguaethol gives 16.1g = 38.7% of theory of 1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane, which crystallizes out from the reaction solution in the cold in the form of the free base. Colorless crystals which have a melting point of 119°-121° and are identical to the product described in Example 28. EXAMPLE 53 (process d) 9.6 g of dihydropyrane are added slowly dropwise to the 3-(2-ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-1-chloropropane, prepared according to Example 33 from 17.8 g of 4-trans-propenylguaethol, 200 ml of epichlorohydrin and 0.5 ml of piperidine, and a catalytic amount of p-toluenesulphonic acid. The mixture is warmed to 40° for 30 minutes and dissolved in 150 ml of isopropanol and 18.3g of diphenylmethylamine and 30 g of potassium carbonate are added. The resulting mixture is then heated to 120° in an autoclave for 10 hours. After the reaction has ended, the inorganic salts are filtered off, 50 ml of hydrochloric acid are added to the filtrate and the mixture is warmed to 80° for 15 minutes. It is then evaporated to dryness in vacuo and the solid residue is recrystallized from methanol/water. This gives 17.5 g = 38.5% of theory of 1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-diphenylaminopropane hydrochloride which has a melting point of 145°-146° and is identical to the product described in Example 1. The compounds which follow are prepared according to the process described in Example 53: EXAMPLE 54 1-(2-Methoxy-4-n-propyl-2-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride, which has a melting point of 108°-110° and is identical to the product described in Example 3, from 1-(2-methoxy-4-n-propyl-phenoxy)-2-(tetrahydropyran-2-yloxy)-3-diphenylmethylaminopropane, which is not isolated. EXAMPLE 55 1-(2-Methoxy-4-allyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride, which has a melting point of 143° and is identical to the product described in Example 4, from 1-(2-methoxy-4-allyl-phenoxy)-2-(tetrahydropyran-2-yloxy)-3-diphenylmethylaminopropane, which is not isolated. EXAMPLE 56 1-(3,4-Dichloro-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride, which has a melting point of 180°-184° and is identical to the product described in Example 37, from 1-(3,4-dichlorophenoxy)-2-(tetrahydropyran-2-yloxy)-3-diphenyl-methylaminopropane, which is not isolated. EXAMPLE 57 1-(2-Ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane, which has a melting point of 119°-121° and is identical to the product described in Example 28, from 1-(2-ethoxy-5-trans-propenyl-phenoxy)-2-tetrahydropyran-2-yloxy)-3-(9-fluorenylamino)-propane, which is not isolated. EXAMPLE 58 (processes c) and d)) A mixture of 27.6 g of 1-diphenylmethylamino-2-hydroxy-3-chloropropane, 10 ml of a 37% strength solution of formaldehyde and 200 ml of benzene is heated to the reflux temperature, while continuously separating off water. The mixture is then evaporated in vacuo and 3-diphenylmethyl-5-chloromethyloxazolidine is obtained as a yellowish oil which, without purification, is heated together with the reacton solution obtained according to Example 43 from 2.3 g of sodium, 100 ml of ethanol and 17.8 g of 4-trans-propenylguaethol, to 100° in an autoclave for 12 hours. After cooling, the sodium chloride which has precipitated is filtered off. 50 ml of 4 N hydrochloric acid are added to the resulting alcoholic solution of 3-diphenylmethyl-5-(2-ethoxy-5-trans-propenyl-phenoxymethyl)-oxazolidine and the mixture is left to stand for 4 hours at room temperature. 1-(2-Ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride, which has precipitated and is identical to the product described in Example 1, is then filtered off. Melting point: 145°-146°; yield: 15.1g = 33.3% of theory. The substances which follow are prepared by the same process: EXAMPLE 59 3-Diphenylmethyl-5-(2-methoxy-4-n-propyl-phenoxymethyl)oxazolidine from 3-diphenylmethyl-5-chloromethyl-oxazolidine and sodium 2-methoxy-4-n-propyl-phenolate; this product is hydrolysed with alcoholic-aqueous hydrochloric acid to give 1-(2-methoxy-4-n-propyl-phenoxy)-2-hydroxy-3-diphenylmethylamino-propane hydrochloride with a melting point of 108°-110°. EXAMPLE 60 3-Diphenylmethyl-5-(2-methoxy-4-allyl-phenoxymethyl)oxazolidine from 3-diphenylmethyl-5-chloromethyl-oxazolidine and sodium eugenolate*; this produce is hydrolysed with alcoholic-aqueous hydrochloric acid to give 1-(2-methoxy-4-allyl-phenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride with a melting point of 143°. EXAMPLE 61 3-Diphenylmethyl-5-(3,4-dichloro-phenoxymethyl)-oxazolidine from 3-diphenylmethyl-5-chloromethyl-oxazolidine and sodium 3,4-dichlorophenolate; this product is hydrolysed with alcoholic-aqueous hydrochloric acid to give 1-(3,4-dichlorophenoxy)-2-hydroxy-3-diphenylmethylaminopropane hydrochloride with a melting point of 180°-184°. EXAMPLE 62 If, in Example 58, the 3-(9-fluorenylamino)-2-hydroxy-1-chloropropane prepared according to Example 52 is used in place of 3-diphenylmethylamino-2-hydroxy-1-chloropropane, this gives 3-(9-fluorenylamino)-5-(2-ethoxy-5-trans-propenylphenoxymethyl)-oxazolidine, which is hydrolysed with alcoholic-aqueous hydrochloric acid. 1-(2-Ethoxy-5-trans-propenyl-phenoxy)-2-hydroxy-3-(9-fluorenylamino)-propane hydrochloride is thus formed and is converted into the free base which has a melting point of 119°-121°.

N-Diphenylmethyl and o-biphenylenemethyl derivatives of 1-(disubstituted phenoxy)-3-amino-2-hydroxypropane and their salts are useful for combatting cerebrovascular insufficiency and producing psychostimulation in humans and other animals. The compounds, of which 1-(2-methoxy-4-allylphenoxy)-2-hydroxy-3-diphenylmethylamino-propane is a typical embodiment, can be prepared by a number of synthetic routes.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. application Ser. No. 10/389,448 filed Mar. 14, 2003, incorporated herein by reference. Cross-reference is also made to U.S. patent application Ser. No. 09/526,679 filed on Mar. 16, 2000, now U.S. Pat. No. 6,553,604, and Ser. No. 09/576,590 filed on May 22, 2000, now U.S. Pat. No. 6,564,416, both of which are assigned to Gillette Canada Company. FIELD OF THE INVENTION [0002] The invention relates generally to the field of oral care, and in particular to toothbrushes. More specifically, the invention relates to a toothbrush head having one or more pivoting tufts of bristles, the head having two portions that can move independent of each other. BACKGROUND OF THE INVENTION [0003] A Japanese patent document having an application number of 3-312978 discloses a toothbrush having a multiplicity of tufts of nylon bristles. In a first embodiment shown in FIGS. 1, 2 and 3 of the document, a plurality of cylindrical recessed sections in the head are set orthogonally to the longitudinal axial direction of a shank and are formed at equal intervals. Column-shaped rotary bodies 5 are respectively contained in the recessed sections. On the peripheral surfaces of the rotary bodies 5 , along the axial direction, projected strip sections 5 a are formed, and they are set in a state that they are positioned at the opening sections of the recessed sections. At the opening sections of the recessed sections, contact surfaces to be positioned on both the sides are formed. At both the ends of the upper surfaces of the projected strip sections 5 a , nylon bristles 6 are arranged to be vertically erected. [0004] As shown in FIG. 3 of the document, the arrangement described above allows bristles 6 to rotate during use of the brush. A problem with this brush is that two tufts of bristles are secured to each strip section 5 a and thus must rotate in unison. As a result, an individual tuft of bristles cannot rotate independently of its “partner” tuft. The individual tuft may thus be prevented from achieving optimal penetration between two teeth during brushing because the partner tuft might contact the teeth in a different manner and interfere with rotation of the individual tuft. [0005] FIGS. 4, 5 and 6 of the document disclose a second embodiment in which each tuft of bristles is secured to the head by a ball and socket type arrangement. While this embodiment allows each tuft of bristles to swivel independent of the other tufts, it does have disadvantages. If a tuft of bristles is tilted out towards the side of the head and that tuft is positioned near the interface between the side and top surfaces of the teeth, chances are increased that the bristle tips will not even be in contact with the teeth during brushing. Further, the random orientation in which the tufts can end up after brushing detracts from the attractiveness of the brush. [0006] The Japanese reference also discloses that the brush head is made of a unitary structure. As such, water cannot flow through any central portion of the brush head, thereby inhibiting the cleanability of the brush. Further, the unitary head structure does not allow different portions of the head to move independently of each other. Accordingly, the bristle tufts extending from the tuft cannot accommodate the varying tooth surfaces as well as a brush in which the head has two or more portions that can move or flex independent of each other. SUMMARY OF THE INVENTION [0007] The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, a toothbrush head has a tooth cleaning element extending from the head. The head is divided into at least two portions which can be moved independent of each other. The tooth cleaning element is rotatable relative to that portion of the head from which it extends. [0008] According to another aspect of the invention, a tooth cleaning element includes one or more tooth cleaners, a base support, and an anchor pivot. One end of the one or more tooth cleaners is secured to a first end of the base support. One end of the anchor pivot is secured to a second end of the base support. The anchor portion has a larger section further from the base support than a smaller section of the anchor portion. [0009] In accordance with a third aspect of the invention, a method of making a toothbrush head includes molding a plastic toothbrush head in a mold. The head has two distinct portions which are spaced a predetermined distance from each other. The head is removed from the mold. At least that part of the head where the two head portions connect is heated. The two head portions are moved towards each other. At least that part of the head where the two head portions connect is cooled such that the two head portions will now remain in positions where they will be spaced apart a distance which is less than the predetermined distance. [0010] According to a fourth aspect of the invention, a method of making a toothbrush head includes molding a plastic toothbrush head in a mold. The head has at least one hole therein which extends all the way through the head. The head is removed from the mold. A tooth cleaning element is inserted into the hole [0011] These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 is a perspective view of the toothbrush head of FIG. 1 ; [0013] FIG. 2 is a top view of the head of FIG. 1 ; [0014] FIG. 3 is a side view of the head of FIG. 1 ; [0015] FIG. 4 is a bottom view of the head of FIG. 1 ; [0016] FIG. 5 is a side view of the head of FIG. 1 showing one of the head portions flexing; [0017] FIG. 6 is a top view of the head of FIG. 1 with the two head portions separated from each other; [0018] FIG. 7 is a top view of the head of FIG. 1 after the head portions have been positioned closer to each other; [0019] FIG. 8 is a front view of a pivoting tuft taken along the lines 8 - 8 of FIG. 13 ; [0020] FIG. 9 is a side view of the pivoting tuft of FIG. 8 taken along lines 9 - 9 ; [0021] FIG. 10 is a top view of one of the holes in the head for receiving the pivoting tuft (see FIG. 6 ); [0022] FIG. 11 is a sectional view of FIG. 10 taken along lines 11 - 11 ; [0023] FIG. 12 is a sectional view of FIG. 10 taken along lines 12 - 12 ; [0024] FIG. 13 is a side view of the head of FIG. 1 (a portion is removed to facilitate viewing) and a pivoting tuft prior to insertion into the head; [0025] FIG. 14 is a side view of the head of FIG. 1 (a portion is removed to facilitate viewing) and a pivoting tuft after insertion into the head; [0026] FIG. 15 is a side view of the pivoting tuft showing its motion; [0027] FIGS. 16 A-C are sectional views of FIG. 15 taken along the lines 16 A-C- 16 A-C; [0028] FIG. 17 is a perspective view of a tooth cleaner in the form of a ribbed fin; and [0029] FIG. 18 is a side view of the ribbed fin of FIG. 17 . DETAILED DESCRIPTION [0030] Beginning with FIGS. 1-5 , there is shown a toothbrush head 16 which extends from a neck 14 which extends from a handle (not shown) to form a toothbrush. The type of handle is not germane to the present invention. The head and handle are preferably made of polypropylene. The head has a serpentine split 18 which divides the head into two portions 20 and 22 . An end of the split 13 near neck 14 is preferably circular in shape (see FIG. 2 ). As shown in FIG. 5 , the split in the head allows portions 20 and 22 to flex or move independent of each other during use of the toothbrush, thus facilitating cleaning of the teeth. [0031] Split 18 can also be defined as an opening in the head between head portions 20 and 22 . This opening allows water to flow through the head, thereby enhancing cleaning of the top head surface which typically gets caked with toothpaste in spite of efforts to rinse the head clean. [0032] Head portion 20 includes a projecting part 24 which fits (at least partially) into a recess 26 (see FIG. 6 ) defined by portion 22 . Projecting part 24 has several tufts of bristles extending from it (to be described in further detail below) and is surrounded on three sides by head portion 22 . [0033] Referring now to FIGS. 2 and 3 , each of the tufts of bristles on head 16 will be described. A first pair of tufts 28 are located towards the free end of the head, one on each head portion 20 , 22 . Each tuft has bristles (tooth cleaners) which preferably are each made of polybutylene-terepthalate (PBT) and have a diameter of 0.007 inches. The shortest bristles in tuft 28 have a length of 0.420 inches with the remaining bristles increasing in length steadily to a tip of the tuft. Each tuft tilts away from the handle by an angle of preferably about 12 degrees relative to that portion of the surface of the head from which it projects. As shown in FIG. 2 , tufts 28 have a larger cross-section than any other tuft on the head. [0034] A second group of tufts are pivoting tufts 30 (the only tufts on the head which are rotatable). There are four tufts 30 on each head portion 20 , 22 which are located towards the outside of the head. Each tuft 30 can pivot up to about 15 degrees to either side of a vertical position on the head, more preferably being able to pivot up to about 8 degrees to either side of a vertical position on the head. The pivoting of tufts 30 is roughly towards or away from neck 14 . Each tuft 30 includes a base support 32 made of polypropylene. The bristles are made of polyamid 6.12, have a diameter of 0.008 inches and extend 0.420 inches above the base support. [0035] A third group of tufts 34 extend perpendicular to the head. There are four tufts 34 on each head portion 20 , 22 which alternate with tufts 30 . When viewed from the top ( FIG. 2 ) the tufts are oval in shape (similar to tufts 30 but larger). In other words, the tufts 34 and 30 have oval shaped cross-sections. Each tuft 34 has bristles which are made of polyamid 6.12, have a diameter of 0.006 inches and extend above the head by about 0.385 inches. [0036] A fourth group of tufts 36 are located towards the inside of the head. There are two such tufts on each head portion 20 , 22 . Each tuft 36 extends perpendicular to the head. The bristles of tuft 36 have a diameter of 0.006 inches, are made of polyamid 6.12 and rise about 0.360 inches above the head. [0037] A fifth and final group of tufts 38 are also located towards the inside of the head (away from a perimeter 21 of the head). There are 4 pairs of tufts 38 . In each pair one tuft is closer to neck 14 than the other tuft. In each pair of tufts 38 , (a) a base of one tuft is closer to a first side of the head and this one tuft leans towards a second side of the head, and (b) a base of the other tuft is closer to the second side of the head and this other tuft leans towards the first side of the head. As such, the tufts in each pair lean across each other. The angle of tilt towards the side of the head is about five degrees. Each tuft 38 bristles which are made of PBT, have a bristle diameter of about 0.007 inches and extend about 0.460 inches above head 16 . Each tuft 38 has an oval cross-section with a long dimension of the oval being oriented in the direction of tilt. [0038] The bristles used on the head can be crimped (see U.S. Pat. No. 6,058,541) or notched (see U.S. Pat. No. 6,018,840). Other types of tooth cleaners besides bristles can be used. For example, a tuft of bristles could be replaced by an elastomeric fin. The US patents listed in this paragraph are incorporated herein by reference. [0039] Turning now to FIG. 6 , a description will now be provided as to how the toothbrush (head) is made. In a first step, the head, neck and handle of the toothbrush are injection molded in a mold. During this injection molding step, tufts 28 , 34 , 36 and 38 are secured in the head by a hot-tufting process. Hot-tufting processes are notoriously well known by those skilled in the art (see e.g. U.S. Pat. Nos. 4,635,313; and 6,361,120; British patent application 2,330,791; and European patent application 676,268 A1). [0040] Briefly, hot-tufting involves presenting ends of a multiplicity of groups of plastic filaments into a mold. Each group of filament ends inside the mold is optionally melted into a blob. Each filament group is cut to a desired length (either before or after being introduced into the mold) to form a tuft of bristles. The mold is closed and molten plastic is injected into the mold. When the plastic solidifies, it locks one end of the tufts of bristles into the head of the toothbrush. [0041] It can be seen in FIG. 6 that the opening 18 between head portions 20 and 22 is much wider at this point than in the heads final form (see FIG. 2 ). In other words, head portions 20 and 22 are spaced a predetermined distance (preferably at least about 1 mm) from each other. Further, through holes 40 are created during the molding step for receiving pivoting tufts 30 at a later point in the manufacturing process. Holes 40 will be described in greater detail below. [0042] With reference to FIG. 7 , after the toothbrush is removed from the mold, heat 42 is applied to the head near the neck and to part of the neck (hereinafter the neck). The heat can be applied in a number of ways including hot air, radiant heating, ultrasonic or convection (e.g. hot oil) heating. Here the heat is shown being applied to the sides of the neck. It is preferable to apply the heat to the top and bottom surface of the neck. The heat brings the plastic up to 1.0-1.12 times its glass transition temperature (when temperatures are measured in the Kelvin scale). The plastic should not be heated above 1.12 times its glass transition temperature in order to avoid damaging the plastic. More preferably, the plastic is heated to about 1.03-1.06 times its glass transition temperature (measured in degrees Kelvin). The glass transition temperature for polypropylene is about 100 degrees centigrade whereas the glass transition temperature for copolyester and polyurethane is about 65 degrees centigrade. [0043] Pressure 44 is then applied to head portions 20 , 22 to move the portions towards each other. Once head portions 20 , 22 are in the position shown in FIG. 2 , the heated portion of the head/neck is cooled by, for example, exposing the heated portion to a cold gas or liquid. If room temperature air is used to cool the neck, such air should be applied for about 20-25 seconds. This has the effect of forming the two head portions into their final positions. [0044] In order to achieve short process times, the highest temperature heat source which will not damage the plastic should be used. If too hot a heat source is used and/or if the heat is applied for too long, the plastic can be damaged. If the heat source is not hot enough, the process will take too long and/or head portions 20 , 22 will not remain in their final desired positions. If the head/neck are made of polypropylene and hot air is used to heat the neck, (a) the heated air should be at a temperature of about 170 degrees centigrade and should be applied to the neck for about 70 seconds, (b) the polypropylene should be raised to a temperature of about 140 degrees centigrade, and (c) a nozzle which applies the hot air to the neck should be about 10 mm from the neck. [0045] If copolyester or polyurethane is used as the material for the head neck, (a) the heated air should be at a temperature of 250 degrees centigrade and should be applied to the neck for about 10 seconds, (b) the material should be raised to a temperature of preferably 95-100 degrees centigrade, and (c) a nozzle which applies the hot air to the neck should be about 15-20 mm from the neck. [0046] Heating the respective materials above for the time indicated allows the material to be softened and mechanically bent into its final form. Exceeding the heating times above could cause the material to overheat and become damaged. [0047] Turning to FIGS. 8 and 9 , each pivoting tuft 30 has a multiplicity of bristles 46 , a base support 48 and an anchor pivot 50 . The bristles are secured to and extend from a first end 52 of the base support while a first end 54 of the anchor pivot extends from a second end 56 of the base support. The base support and anchor pivot are preferably a unitary structure made of the same material. Anchor pivot 50 includes a first portion 58 near the first end 54 and a second portion 60 near a second end 62 of the anchor pivot. First portion 58 is smaller in an X an Y dimension than second portion 60 . Base support 48 is larger in an X and Y dimension than second portion 60 of the anchor support. Second portion 60 includes a pair of lips 63 . The anchor pivot defines an opening 64 therethrough. [0048] Tuft 30 can also be made by a hot-tufting type process as described above. Instead of injecting plastic into the mold to form a toothbrush handle, neck and head, the plastic is injected into a mold to form base support 48 and anchor pivot 50 , capturing bristles 46 when the injected plastic cools. [0049] With reference to FIGS. 10-12 , through holes 40 ( FIG. 6 ) will now be described. Each hole 40 extends from a top surface 66 of the brush head through a bottom surface 68 . Hole 40 includes first and second portions 70 and 72 . Portion 72 is substantially a parallelepiped except that some of its lower section is rounded off (see FIG. 11 ). Portion 70 is also substantially a parallelepiped except that two of its sides are flared to the sides by about 15 degrees (see FIG. 12 ). Hole portion 72 is longer in a dimension A than hole portion 70 ( FIG. 11 ). Hole portion 70 has about the same width in a dimension B as hole portion 72 where hole portions 70 and 72 meet ( FIG. 12 ). Dimensions A and B are substantially perpendicular to each other in this embodiment. A pair of lips 73 are defined by this arrangement. [0050] Turning now to FIGS. 13-16 , the insertion of pivoting tufts 30 into holes 40 will be described. A tuft 30 is positioned over a hole 40 with end 62 of anchor pivot 50 facing the hole ( FIG. 13 ). As shown in FIGS. 16 A-C, tuft 30 is moved towards hole 40 until end 62 starts to enter the hole ( FIG. 16A ). Tuft 30 is then pressed into the hole causing sides of hole portion 70 to squeeze second portion 60 of the anchor pivot. Accordingly, anchor pivot 50 collapses causing opening 64 to become temporarily smaller. Tuft 30 is then pushed all the way into hole 40 ( FIG. 16C ) at which point the resilient plastic anchor pivot springs back to its form shown in FIG. 16A . This paragraph describes a snap-fit retention of tuft 30 to the head. [0051] Referring to FIG. 16C , base support 48 is longer in the A dimension than hole portion 70 and thus prevents tuft 30 from being pressed further into hole 40 . Second portion 60 is also longer in the A dimension than hole portion 70 and so prevents tuft 30 from moving back out of hole 40 . This is due to the fact that lips 63 ( FIG. 8 ) engage lips 73 ( FIG. 11 ). This arrangement also prevents tuft 30 from rotating about the long axis of the bristles. [0052] As shown in FIG. 15 , tuft 30 pivots when it is engaged by, for example, portions of the oral cavity during brushing. Preferably each tuft 30 can pivot up to about 15 degrees to either side of a position perpendicular to surface 66 . [0053] Turning to FIGS. 17 and 18 , another type of tooth cleaning element in the form of a fin 80 is disclosed. Each fin is supported by a base support 48 and an anchor pivot 50 (both not shown) as described above, allowing the fin to pivot on the brush head. Alternatively, a fin can be securely affixed to the head so that it does not pivot. The fin is created of a thermoplastic elastomer (TPE) by an injection molding process. In this embodiment, a textured surface is provided by a series of ribs 82 . These ribs enhance cleaning of the oral cavity. The ribs are formed by injection molding a TPE over the fin. The ribs are preferably softer than the fin. Alternative textured surfaces (e.g. dimples) can be used in place of the ribs. [0054] As shown in FIG. 18 , the fin has a width of preferably about 0.030 inches. The long dimension of the fin above the base support is preferably 0.420 inches. A tip 84 of fin 80 has a width of preferably 0.007 inches. The distance from the base of the ribs to tip 84 is about 0.168 inches whereas the distance from the top of the ribs to the tip is about 0.079 inches. The top of the ribs have a width of about 0.035 inches. The ribs (textured surface) preferably extend about 2-12 mil away from said fin. [0055] The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.

A toothbrush has a handle and a head part, on which bristle filaments and at least one flexible cleaning element are arranged. The at least one flexible cleaning element is arranged on a carrier element which consists of a hard material and is connected to the head part. A process for producing such a toothbrush is also disclosed.

This application claims priority to provisional U.S. Patent Application Ser. No. 60/489,086 filed on Jul. 22, 2003 entitled “PIPELINE STRUCTURE FOR A SHARED MEMORY PROTOCOL” by Weiss et al. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to processor-based systems, and, more particularly, to providing a higher bandwidth, lower-latency implementation of a scaled shared memory (SSM) protocol. 2. Description of the Related Art Businesses typically rely on network computing to maintain a competitive advantage over other businesses. As such, developers, when designing processor-based systems for use in network-centric environments, may take several factors into consideration to meet the expectation of the customers, factors such as functionality, reliability, scalability, and performance of such systems. One example of a processor-based system used in a network-centric environment is a mid-range server system. A single mid-range server system may have a plurality of system boards that may, for example, be configured as one or more domains, where a domain, for example, may act as a separate machine by running its own instance of an operating system to perform one or more of the configured tasks. A mid-range server, in one embodiment, may employ a distributed shared memory system, where processors from one system board can access memory contents from another system board. The union of all of the memories on the system boards of the mid-range server comprises a distributed shared memory (DSM). One method of accessing data from other system boards within a system is to broadcast a memory request on a common bus. For example, if a requesting system board desires to access information stored in a memory line residing in a memory of another system board, the requesting system board typically broadcasts on the common bus its memory access request. All of the system boards in the system may receive the same request and the system board whose memory address ranges match the memory address provided in the memory access request may then respond. The broadcast approach for accessing contents of memories in other system boards may work adequately when a relatively small number of system boards are present in a system. However, such an approach may be unsuitable as the number of system boards grows. As the number of system boards grows, so does the number of memory access requests, thus to handle this increased traffic, larger and faster buses may be needed to allow the memory accesses to complete in a timely manner. Operating a large bus at high speeds may be problematic because of electrical concerns, in part, due to high capacitance, inductance, and the like. Furthermore, a larger number of boards within a system may require extra broadcasts, which could further add undesirable delays and may require additional processing power to handle the extra broadcasts. Designers have proposed the use of directories in a distributed shared memory system to reduce the need for globally broadcasting memory requests. Typically, each system board serves as a home board for memory lines within a selected memory address range, and where each system board is aware of the memory address ranges belonging to the other system boards within the system. Each home board generally maintains its own directory for memory lines that fall within its address range. Thus, when a requesting board desires to access memory contents from another board, instead of generally broadcasting the memory request in the system, the request is transmitted to the appropriate home board. The home board may consult its directory and determine which system board is capable of responding to the memory request and identify any system boards that need to be informed of the request. Directories are generally effective in reducing the need for globally broadcasting memory requests during memory accesses. However, implementing a directory that is capable of mapping every memory location within a system board generally represents a significant memory overhead. As such, directory caches are often designed to hold only mappings for a subset of the total memory. The system typically must use some other method, such as broadcasting, to resolve requests for memory that are not currently mapped in the directory cache. Communication requests between the multiple boards described above (e.g., the requesting board and the home board) generally cause them to develop a client/server relationship. Communications between the multiple boards with client/server relationships may experience an inherent latency of operation during communications between the client and the server. Many times, several system clock cycles may pass during which no significant activity relating to transactions between the client and the server is accomplished. This results in communication latency, which may adversely affect the operation of the server. Often, latency in communications between the requesting board and the home board may cause several portions of a transaction request to be placed in a queue. An appreciable number of requests may be queued, which may slow the operation of the server. While transaction requests are queued, several system clock cycles may be bypassed due to the latency of communication operations. This may cause a backlog to develop in a queue, which may slow the operation of the server. The present invention is directed to overcoming, or at least reducing, the effects of, one or more of the problems set forth above. SUMMARY In one aspect of the present invention, a method is provided for implementation of a pipeline structure for data transfer. A request is received from a first domain to access a second domain during a first clock cycle. A pipeline structure is used to perform at least a portion of the request during a subsequent clock cycle. In another aspect of the present invention, a method is provided for implementation of a pipeline structure for data transfer. A request is received from a first domain to access a second domain during a first clock cycle. A determination is made as to whether a latency of operation relating to the request is above a predetermined threshold. A latency reduction process is performed in response to the determination that the latency of operation relating to the request is above a predetermined threshold. The latency reduction process includes using a pipeline protocol to perform at least a portion of the request during a clock cycle substantially immediately following the first clock cycle. In another aspect of the instant invention, an apparatus is provided for the implementation of a pipeline structure for data transfer. The apparatus of the present invention includes an interface and a first control unit that is communicatively coupled to the interface. The first control unit is adapted to: receive a request from a first domain for data that is storable in a resource associated with a second domain during a first clock cycle; access the data from the resource associated with the second domain using a pipeline structure unit; provide the data to the first domain based upon a pipeline structure provided by the pipeline structure unit; and to provide an indication to the first domain in response to providing the data. In yet another aspect of the present invention, a computer readable program storage device encoded with instructions is provided for implementation of a pipeline structure for data transfer. A computer readable program storage device encoded with instructions that, when executed by a computer, performs a method, which comprises: receiving a request from a first domain to access a second domain during a first clock cycle; and using a pipeline structure to perform at least a portion of the request during a subsequent clock cycle. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a block diagram depiction of a system in accordance with one illustrative embodiment of the present invention. FIG. 2 illustrates a block diagram depiction of an illustrative domain configuration that may be implemented in the system of FIG. 1 , in accordance with one illustrative embodiment of the present invention. FIG. 3 illustrates a block diagram depiction of a system board set that may be implemented in the system of FIG. 1 , in accordance with one illustrative embodiment of the present invention. FIGS. 4A , 4 B, and 4 C illustrate a directory cache entry that may be implemented in the system of FIG. 1 , in accordance with one illustrative embodiment of the present invention. FIG. 5 illustrates a state diagram including the various communication paths between one or more boards of the system of FIG. 1 , in accordance with one illustrative embodiment of the present invention. FIG. 6 illustrates a flowchart depiction of the method in accordance with one illustrative embodiment of the present invention. FIG. 7 illustrates a more detailed flowchart depiction of the step of performing a latency reduction process, as indicated in FIG. 6 , in accordance with one illustrative embodiment of the present invention. FIG. 8 illustrates a more detailed flowchart depiction of the step of performing a request agent protocol, as indicated in FIG. 7 , in accordance with one illustrative embodiment of the present invention. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. Note, the headings are for organizational purposes only and are not meant to be used to limit or interpret the description or claims. Furthermore, note that the word “may” is used throughout this application in a permissive sense (i.e., having the potential to, being able to), not a mandatory sense (i.e., must). The term “include” and derivations thereof mean “including, but not limited to.” The term “connected” means “directly or indirectly connected,” and the term “coupled” means “directly or indirectly coupled.” DETAILED DESCRIPTION Embodiments of the present invention provide for improving the bandwidth relating to communications between multiple portions of a server system. The improvements in the bandwidth provided by embodiments of the present invention may be used to reduce the latency of communications between a plurality of portions of the server system. Embodiments of the present invention provide for implementing a pipeline structure such that substantially every clock cycle of a system clock may be used to implement or execute at least a portion of a transaction into the pipeline structure. Embodiments of the present invention provide for reducing the latency of communication systems for improved response to a transaction request made by a portion of a server system. Turning now to FIG. 1 , a block diagram depiction of a system 10 , in accordance with one illustrative embodiment of the present invention, is provided. The system 10 , in one embodiment, includes a plurality of system control boards 15 ( 1 −2) that are coupled to a switch 20 . For illustrative purposes, lines 21 ( 1 −2) are utilized to show that the system control boards 15 ( 1 −2) are coupled to the switch 20 , although it should be appreciated that, in other embodiments, the boards 15 ( 1 −2) may be coupled to the switch 20 in any of a variety of ways, including by edge connectors, cables, or other available interfaces. In the illustrated embodiment, the system 10 includes two control boards 15 ( 1 −2), one for managing the overall operation of the system 10 and the other to provide redundancy and automatic failover in the event that the other board fails. Although not so limited, in the illustrated embodiment, the first system control board 15 ( 1 ) serves as a “main” system control board, while the second system control board 15 ( 2 ) serves as an alternate hot-swap replaceable system control board. In one embodiment, during any given moment, generally one of the two system control boards 15 ( 1 −2) actively controls the overall operations of the system 10 . If failures of the hardware or software occur on the main system control board 15 ( 1 ), or failures on any hardware control path from the main system control board 15 ( 1 ) to other system devices occur, the system controller failover software 22 automatically triggers a failover to the alternative control board 15 ( 2 ). The alternative system control board 15 ( 2 ), in one embodiment, assumes the role of the main system control board 15 ( 1 ) and takes over the responsibilities of the main system control board 15 ( 1 ). To accomplish the transition from the main system control board 15 ( 1 ) to the alternative system control board 15 ( 2 ), it may be desirable to replicate the system controller data, configuration, and/or log files on both of the system control boards 15 ( 1 −2). The system control boards 15 ( 1 −2) in the illustrated embodiment may each include a respective control unit 23 ( 1 −2). The system 10 , in one embodiment, includes a plurality of system board sets 29 ( 1 −n) that are coupled to the switch 20 , as indicated by lines 50 ( 1 −n). The system board sets 29 ( 1 −n) may be coupled to the switch 20 in one of several ways, including edge connectors or other available interfaces. The switch 20 may serve as a communications conduit for the plurality of system board sets 29 ( 1 −n), half of which may be connected on one side of the switch 20 and the other half on the opposite side of the switch 20 . The switch 20 , in one embodiment, may allow system board sets 29 ( 1 −n) to communicate, if desired. Thus, the switch 20 may allow the two system control boards 15 ( 1 −n) to communicate with each other or with other system board sets 29 ( 1 −n), as well as allow the system board sets 29 ( 1 −n) to communicate with each other. The system board sets 29 ( 1 −n), in one embodiment, comprise one or more boards, including a system board 30 , I/O board 35 , and expander board 40 . The system board 30 may include processors and associated memories for executing, in one embodiment, applications, including portions of an operating system. The I/O board 35 may manage I/O cards, such as peripheral component interface cards and optical cards that are installed in the system 10 . The expander board 40 , in one embodiment, generally acts as a multiplexer (e.g., 2:1 multiplexer) to allow both the system board 30 and I/O board 35 to interface with the switch 20 , which, in some instances, may have only one slot for interfacing with both boards 30 , 35 . In one embodiment, the system 10 may be dynamically subdivided into a plurality of system domains, where each domain may have a separate boot disk (to execute a specific instance of the operating system, for example), separate disk storage, network interfaces, and/or I/O interfaces. Each domain, for example, may operate as a separate machine that performs a variety of user-configured services. For example, one or more domains may be designated as an application server, a web server, database server, and the like. In one embodiment, each domain may run its own operating system (e.g., Solaris operating system) and may be reconfigured without interrupting the operation of other domains. FIG. 2 illustrates an exemplary arrangement where at least two domains are defined in the system 10 . The first domain, identified by vertical cross-sectional lines, includes the system board set 29 (n/ 2 + 2 ), the system board 30 of the system board set 29 ( 1 ), and the I/O board 35 of the system board set 29 ( 2 ). The second domain in the illustrated embodiment includes the system board sets 29 ( 3 ), 29 (n/ 2 + 1 ), and 29 (n/ 2 + 3 ), as well as the I/O board 35 of the system board set 29 ( 1 ) and the system board 30 of the system board set 29 ( 2 ). As shown, a domain may be formed of an entire system board set 29 ( 1 −n), one or more boards (e.g., system board 30 , I/O board 35 ) from selected system board sets 29 ( 1 −n), or a combination thereof. Although not necessary, it may be possible to define each system board set 29 ( 1 −n) as a separate domain. For example, if each system board set 29 ( 1 −n) were its own domain, the system 10 may conceivably have up to “n” (i.e., the number of system board sets) different domains. When two boards (e.g., system board 30 , I/O board 35 ) from the same system board set 29 ( 1 −n) are in different domains, such a configuration is referred to as a “split expander.” The expander board 40 of the system board sets 29 ( 1 −n), in one embodiment, keeps the transactions separate for each domain. No physical proximity may be needed for boards in a domain. Using the switch 20 , inter-domain communications may be possible. For example, the switch 20 may provide a high-speed communications path so that data may be exchanged between the first domain and the second domain of FIG. 2 . In one embodiment, a separate path for data and address through the switch 20 may be used for inter-domain communications. Referring now to FIG. 3 , a block diagram of the system board set 29 ( 1 −n) coupled to the switch 20 is illustrated, in accordance with one embodiment of the present invention. The system board 30 of each system board set 29 ( 1 −n) in the illustrated embodiment includes four processors 360 ( 1 −4), with each of the processors 360 ( 1 −4) having an associated memory 361 ( 1 −4). In one embodiment, each of the processors 360 ( 1 −4) may be coupled to a respective cache memory 362 ( 1 −4). In other embodiments, each of the processors 360 ( 1 −4) may have more than one associated cache memories 362 ( 1 −4), wherein some or all of the one or more cache memories 362 ( 1 −4) may reside within the processors 360 ( 1 −4). In one embodiment, each cache memory 362 ( 1 −4) may be a split cache, where a storage portion of the cache memory 362 ( 1 −4) may be external to the processor, and a control portion (e.g., tags and flags) may be resident inside the processors 360 ( 1 −4). The processors 360 ( 1 −4), in one embodiment, may be able to access their own respective memories 361 ( 1 −4) and cache memories 362 ( 1 −4), as well as access the memories associated with other processors. In one embodiment, a different number of processors and memories may be employed in any desirable combination, depending on the implementation. In one embodiment, two five-port dual data switches 365 ( 1 −2) connect the processor/memory pairs (e.g., processors 360 ( 1 −2)/memories 361 ( 1 −2) and processors 360 ( 3 −4)/memories 361 ( 3 −4)) to a board data switch 367 . Although not so limited, the I/O board 35 of each system board set 29 ( 1 −n) in the illustrated embodiment includes a controller 370 for managing one or more of the PCI cards that may be installed in one or more PCI slots 372 ( 1 −p). In the illustrated embodiment, the I/O board 35 also includes a second controller 374 for managing one or more I/O cards that may be installed in one or more I/O slots 376 ( 1 −o). The I/O slots 376 ( 1 −o) may receive optic cards, network cards, and the like. The I/O board 35 , in one embodiment, may communicate with the system control board 15 ( 1 −2) (see FIG. 1 ) over an internal network (not shown). The two controllers 370 , 374 of the I/O board 35 , in one embodiment, are coupled to a data switch 378 . A switch 380 in the expander board 40 receives the output signal from the data switch 378 of the I/O board 35 and from the switch 367 of the system board set 29 ( 1 −n) and provides it to a System Data Interface (SDI) 383 , in one embodiment. The SDI 383 may process data transactions to and from the switch 20 and the system board 30 and I/O board 35 . A separate address path (shown in dashed lines) is shown from the processors 360 ( 1 −4) and the controllers 370 , 374 to the coherency module 382 . In the illustrated embodiment, the SDI 383 includes a buffer 384 , described in more detail below. The coherency module 382 may process address and response transactions to and from the switch 20 and the system and I/O boards 30 and 35 . In one embodiment, the switch 20 may include a data switch 385 , address switch 386 , and response switch 388 for transmitting respective data, address, and control signals provided by the coherency module 382 or SDI 383 of each expander board 40 of the system board sets 29 ( 1 −n). Thus, in one embodiment, the switch 20 may include three 18×18 crossbar switches that provide a separate data path, address path, and control signal path to allow intra- and inter-domain communications. Using separate paths for data, addresses, and control signals, may reduce the interference among data traffic, address traffic, and control signal traffic. In one embodiment, the switch 20 may provide a bandwidth of about 43 Gigabytes per second. In other embodiments, a higher or lower bandwidth may be achieved using the switch 20 . It should be noted that the arrangement and/or location of various components (e.g., coherency module 382 , processors 360 ( 1 −4), controllers 370 , 374 ) within each system board set 29 ( 1 −4) is a matter of design choice, and thus may vary from one implementation to another. Additionally, more or fewer components may be employed without deviating from the scope of the present invention. In accordance with one embodiment of the present invention, cache coherency is performed at two different levels, one at the intra-system board set 29 ( 1 −n) level and one at the inter-system board set 29 ( 1 −n) level. With respect to the first level, cache coherency within each system board set 29 ( 1 −n) is performed, in one embodiment, using conventional cache coherency snooping techniques, such as the modified, owned, exclusive, shared, and invalid (MOESI) cache coherency protocol. Memory lines transition into the 0 state from M if another processor 360 ( 1 −4) requests a shared copy. A line in the 0 state cannot be modified, and is written back to memory when victimized. It represents a shared line for which the data in memory is out of date. The processors 360 ( 1 −4) may broadcast transactions to other devices within the system board set 29 ( 1 −n), where the appropriate device(s) may then respond with the desired results or data. Because the number of devices within the system board set 29 ( 1 −n) may be relatively small, a conventional coherency snooping technique, in which requests are commonly broadcasted to other devices, may adequately achieve the desired objective. However, because the system 10 may contain a large number of system board sets 29 ( 1 −n), each having one or more processors 360 ( 1 −4), memory accesses may require a large number of broadcasts before such requests can be serviced. Accordingly, a second level of coherency may be performed at the system level (between the expander boards 40 ) by the coherency module 382 of each expander board 40 using, in one embodiment, the scalable shared memory (SSM) protocol. The coherency module 382 , in one embodiment, includes a control unit 389 coupled to a home agent 390 , a request agent 392 , and a slave agent 394 . Collectively, the agents 390 , 392 , 394 may operate to aid in maintaining system-wide coherency. In the illustrated embodiment, the control unit 389 of the coherency module 382 interconnects the system board 30 and the I/O board 35 as well as interconnects the home agent 390 , request agent 392 , and slave agent 394 within the coherency module 382 . In one embodiment, if the expander board 40 is split between two domains (i.e., the system and the I/O boards 30 and 35 of one system board set 29 ( 1 −n) are in different domains), the control unit 389 of the coherency module 382 may arbitrate the system board 30 and I/O board 35 separately, one on odd cycles and the other on even cycles. The coherency module 382 may also include a pipeline structure unit 393 that is capable of providing a pipeline structure for executing transactions requested by various portions of the system 10 . Tasks handled by the request agent 392 and/or the home agent 390 may be positioned in a pipeline format by the pipeline structure unit 393 . In one embodiment, on substantially every system clock cycle, a new transaction is moved into the pipeline provided by the pipeline structure unit 393 such that a portion of a requested transaction is performed on each system clock cycle. Performing a portion of a transaction on substantially every system clock cycle increases the bandwidth of the SSM protocol. A more detailed description of increasing the bandwidth of the SSM protocol is provided below. The pipeline structure unit 393 may be a software, hardware, or firmware unit that is a standalone unit or may be integrated into a control unit 389 . The pipeline structure unit 393 may be implemented into various portions of the system 10 , including the expander board 40 , the system board 30 , and/or the I/O board 35 . The SSM protocol uses MTags embedded in the data to control what the devices under the control of each expander board 40 can do to a cache line. The MTags may be stored in the caches 362 ( 1 −4) and/or memories 361 ( 1 −4) of each system board set 29 ( 1 −n). Table 1 below illustrates three types of values that may be associated with MTags. TABLE 1 MTag Type Description Invalid (gI) No read or write allowed for this type of line. A device must ask for a new value before completing an operation with this line. Shared (gS) A read may complete, but not a write. Modifiable (gM) Both reads and writes are permitted to this line. As mentioned, the Mtag states are employed in the illustrated embodiment in addition to the conventional MOESI cache coherency protocol. For example, to do a write, a device should have a copy of the line that is both M and gM. If the line is gM but not M, then the status of the line may be promoted to M with a transaction within the expander board 40 . If the line is not gM, then a remote transaction may have to be done involving the cache coherency module 382 , which, as mentioned, employs the SSM protocol in one embodiment. The coherency module 382 , in one embodiment, controls a directory cache (DC) 396 that holds information about lines of memory that have been recently referenced using the SSM protocol. The DC 396 , in one embodiment, may be stored in a volatile memory, such as a static random access memory (SRAM). The DC 396 may be a partial directory in that it may not have enough entry slots to hold all of the cacheable lines that are associated with a given expander board 40 . As is described in more detail later, the coherency module 382 , in one embodiment, controls a locking module 398 that prevents access to a selected entry in the directory cache 396 when the status of that entry, for example, is being updated. The DC 396 may be capable of caching a predefined number of directory entries corresponding to cache lines of the caches 362 ( 1 −4) for a given system board 30 . The DC 396 may be chosen to be of a suitable size so that a reasonable number of commonly used memory blocks may generally be cached. Although not so limited, in the illustrated embodiment, the DC 396 is a 3-way set-associative cache, formed of three SRAMs that can be read in parallel. An exemplary 3-wide DC entry is shown in FIG. 4A . The DC 396 , in one embodiment, includes 3-wide DC entries (collectively referred to as a “set”) 410 . Each DC entry in a given set 410 may be indexed by a partial address. As shown in FIG. 4A , in one embodiment, each of the three DC entry fields 415 ( 0 −2) has an associated address parity field 420 ( 0 −2). Each set 410 includes an error correction code (ECC) field 425 ( 0 −1). In case of errors, the ECC field 425 ( 0 −1) may allow error correction, in some instances. Each 3-wide DC entry in a given set 410 includes a least recently modified (LRM) field 430 that may identify which of the three DC entry fields 415 ( 0 −2) was least recently modified. Although other encoding techniques may be employed, in the illustrated embodiment, three bits are used to identify the LRM entry. An exemplary list of LRM codes employed in the illustrated embodiment is provided in Table 2 below. TABLE 2 DC Least-Recently-Modified encoding LRM Most Recent Middle Least Recent 000 Entry 0 Entry 1 Entry 2 001 Entry 1 Entry 0 Entry 2 010 Entry 2 Entry 0 Entry 1 011 ***undefined state *** 100 Entry 0 Entry 2 Entry 1 101 Entry 1 Entry 2 Entry 0 110 Entry 2 Entry 1 Entry 0 111 *** undefined state *** As indicated in the exemplary LRM encoding scheme of Table 2, various combinations of bits in the LRM field 430 identify the order in which the three entry fields 415 ( 0 −2) in the DC 396 were modified. As an example, the digits ‘000’ (i.e., the first entry in Table 2), indicate that the entry field 415 ( 2 ) was least recently modified, followed by the middle entry field 415 ( 1 ), and then the first entry field 415 ( 0 ), which was most recently modified. As an added example, the digits ‘101’ indicate that the entry field 415 ( 0 ) was least recently modified, followed by the entry field 415 ( 2 ), and then the entry field 415 ( 1 ), which was most recently modified. As described later, the LRM field 430 , in one embodiment, is utilized, in part, to determine which DC entry field 415 ( 0 −2) to victimize from a particular set 410 of the DC 396 when that set 410 is full. In accordance with one embodiment of the present invention, two different types of entries, a shared entry 435 and an owned entry 437 , may be stored in the entry fields 415 ( 0 −2) of the DC 396 , as shown in FIGS. 4B-C . An owned entry 437 , in one embodiment, signifies expander board 40 has both read and write access for that particular entry. A shared entry 435 , in one embodiment, indicates that one or more expander boards 40 have read, but not write, access for that particular entry. The shared entry 435 , in one embodiment, includes an identifier field 440 , a mask field 445 , and an address tag field 450 . The identifier field 440 , in the illustrated embodiment, is a single bit field, which, if equal to bit 1 , indicates that the stored cache line is shared by one or more of the processors 360 ( 1 −4) of the system board sets 29 ( 1 −n) in the system 10 . The mask field 445 , which may have up to “n” bits (i.e., one bit for each of the system board sets 29 ( 1 −n)), identifies through a series of bits which of the system boards 30 of the system board sets 29 ( 1 −n), has a shared copy of the cache line. The address tag field 450 may store at least a portion of the address field of the corresponding cache line, in one embodiment. The owned entry 437 includes an identifier field 455 , an owner field 460 , an address tag field 465 , a valid field 470 , and a retention bit field 475 , in one embodiment. The identifier field 455 , in the illustrated embodiment, is a single bit field, which, if equal to bit 0 , indicates that the stored cache line is owned by the named expander in the system 10 . The owner field 460 is adapted to store the identity of a particular expander board 40 of the system board sets 29 ( 1 −n) that holds the valid copy of the cache line. The address tag field 465 may be adapted to store at least an identifying portion of the address field of the corresponding cache line, in one embodiment. For example, the tag field 465 may be comprised of the upper order bits of the address. The valid field 470 , in one embodiment, indicates if the corresponding entry in the DC 396 is valid. An entry in the DC 396 may be invalid at start-up, for example, when the system 10 or domain in the system 10 is first initialized. If the invalid bit is “0,” an actual ownership of a line by a named expander is recorded in the owner field 460 . Referring now to FIG. 5 , a state diagram including the various communication paths between a requesting board 510 , a home board 520 , and slave board 530 in servicing memory access requests is illustrated, in accordance with one or more embodiments of the present invention. The boards 510 , 520 , 530 , in one embodiment, may include one or more boards (e.g., expander board 40 , system board 30 , I/O board 35 ) of one or more control board sets 29 ( 1 −n). The term “memory access requests,” as utilized herein, may include, in one embodiment, one or more of the processors 360 ( 1 −4) (see FIG. 3 ) of a given system board set 29 ( 1 −n) accessing one or more caches 362 ( 1 −4) or memories 361 ( 1 −4) in the system 10 . Although the invention is not so limited, for the purposes of this discussion, it is herein assumed that one domain is configured in the system 10 that is formed of one or more complete (i.e., no split expanders) system board sets 29 ( 1 −n). Generally, a given cache line in the system 10 is associated with one home board 520 . The requesting board 510 in the illustrated embodiment represents a board attempting to access a selected cache line. The slave board 530 in the illustrated embodiment represents a board that currently has a copy of a cache line that the requesting board 510 is attempting to access. In a case where a current copy of a requested cache line resides in the home board 520 , then the home board 520 is also the slave board 530 for that transaction. The requesting board 510 may initiate one of a variety of memory access transactions, including request-to-own (RTO), request-to-share (RTS), WriteStream, WriteBack, and ReadStream transactions. One or more of the aforementioned memory access transactions may be local or remote transactions, where local transactions may include transactions that are broadcast locally within the system board set 29 ( 1 −n) and remote transactions may include transactions that are intended to access cache lines from other system board sets 29 ( 1 −n). Although not so limited, in one embodiment, an RTO may be issued to obtain an exclusive copy of a cache line, an RTS to obtain a shared copy of a cache line, a WriteBack transaction to write the cached line back to the home board, a ReadStream request to get a snapshot copy of the cache line, and a WriteStream request to write a copy of the cache line. For illustrative purposes, an exemplary RTO transaction among the boards 510 , 520 , and 530 is described below. For the purpose of this illustration, it is herein assumed that the requesting board 510 is attempting to obtain write-access to a cache line owned by the home board 520 , where the latest copy of the requested cache line resides on the slave board 530 . The RTO from the requesting board 510 is forwarded to the home board 520 via path 540 . Forwarding of the RTO from the requesting board 510 to the home board 520 is typically handled by the coherency module 382 (see FIG. 3 ) of the requesting board 510 utilizing the address provided with the RTO. The requesting board 510 determines which of the home boards 520 has the requested cache line by, for example, mapping the address of the cache line to the address ranges of the caches associated with the various expander boards 40 within the system 10 . When the home board 520 receives the RTO message over the path 540 , the coherency module 382 of the home board 520 checks its directory cache 396 (see FIG. 3 ) to determine if there is an entry corresponding to the requested cache line. Assuming that an entry exists in the directory cache 396 , the home board 520 may reference the information stored in that entry to determine if the slave board 530 currently has an exclusive copy of the requested cache line. It should be noted, in one embodiment, that while the directory cache 396 of the home board 520 is being referenced, the coherency module 382 may use the locking module 398 to at least temporarily prevent other expander boards 40 from accessing that entry in the directory cache 396 . Based on the information stored in the directory cache 396 , the home board 520 is able to ascertain, in one embodiment, that the slave board 530 currently has an exclusive copy of the cache line. Accordingly, the home board 520 , in one embodiment, transmits a request over a path 545 to the slave board 530 to forward a copy of the requested cache line to the requesting board 510 . In one embodiment, the slave board 530 downgrades its copy from an exclusive copy (i.e., M-type) to an invalid copy (i.e., I-type) since, by definition, if one board in the system 10 has an exclusive M-copy (i.e., the requesting board 510 in this case), all other nodes should have invalid I-copies. When the requesting board 510 receives a copy of the cache line over a path 550 , it internally notes that it now has an exclusive M-copy and acknowledges over a path 555 . When the home board 520 receives the acknowledgment message from the requesting board 510 over the path 555 , the home board 520 updates its directory cache 396 to reflect that the requesting board 510 now has write-access to the cache line, and may use the locking module 398 to allow other transactions involving the cache line to be serviced. The paths 540 , 545 , 550 , and 555 , in one embodiment, may be paths through the switch 20 (see FIGS. 1 and 3 ). As other transactions occur for accessing cache lines in the home board 520 , for example, the coherency module 382 of the home board 520 routinely may update its directory cache 396 to reflect the status of the referenced cache lines. The status of the referenced cache lines may include information regarding the state of the cache line (e.g., M, I, S), ownership rights, and the like. At any given time, because of the finite size of the directory cache 396 , it may be possible that a particular set 410 within the directory cache 396 may be full. When a particular set 410 within the directory cache 396 is full, it may be desirable to discard or overwrite old entries to store new entries since it may be desirable to retain some entries in the directory cache 396 over others. Embodiments of the present invention provide for servicing at least a portion of a transaction between the requesting boards 510 , the home board 520 , and/or the slave board 530 in response to virtually every clock cycle. Turning now to FIG. 6 , a flow chart depiction of the methods in accordance with one illustrative embodiment of the present invention is provided. The system 10 provides for developing a client/server relationship between the requesting board 510 and the home board 520 and/or the slave board 530 for executing transactions, such as memory transactions (block 610 ). For example, the requesting board 510 may initiate a memory access transaction and a write back transaction to write the cache line back to the home board 520 . The transaction may be queued in response to a determination that the home agent 390 in the coherency module 382 is not prepared to execute the requested transaction. The system 10 may then determine a latency of operation related to the communications between the client/server described above (block 620 ). The system 10 may calculate or determine that the latency may be above a predetermined threshold (block 630 ). The latency threshold may depend upon a predetermined acceptable latency set by the system 10 . When the system 10 determines that the latency is at or below the predetermined threshold, normal communication described above is continued (block 640 ). However, when the system 10 determines that the latency is above the predetermined threshold, a latency reduction process in response to the latency is implemented by the system 10 (block 650 ). Embodiments of the present invention provide for implementing a high-bandwidth, low-latency communications protocol. For example, pipeline structures may be set-up such that during virtually every clock cycle, a new transaction may be moved into position into the pipeline structure described above, to perform the requested portion of the transaction function. In one embodiment, the pipeline structure unit 393 is used by the system 10 to utilize substantially every clock cycle to perform at least a portion of the requested transaction. A more detailed description and illustration of the latency reduction process indicated in block 650 of FIG. 6 , is provided in FIG. 7 . Turning now to FIG. 7 , a flowchart depiction of the methods for performing a client/server transaction in accordance with an illustrative embodiment of the present invention is provided. When the system 10 receives a request for a transaction, such as a memory transaction, a request agent protocol is performed (block 710 ). The request agent protocol involves searching for a transaction to be handled by the SSM protocol. A more detailed description of the request agent protocol is provided in FIG. 8 and accompanying description below. Upon performing the request agent protocol, the system 10 determines if the target home agent 390 of one of the boards 510 , 520 , 530 is ready to execute the request (block 720 , 730 ). If the target home agent 390 is not ready to execute the requested transaction, the transaction is placed into a queue (block 740 ). The requested transaction is removed from the queue when the target home agent 390 is ready to execute the transaction. When the home agent 390 is ready to execute the transaction request, the system 10 performs a lock transaction (block 750 ). In one embodiment, the system 10 may use the locking module 398 to prevent other entities in the system 10 from accessing a particular entry in the directory cache 396 of the target home board 520 . The system 10 then compares the transaction that is requested to currently outstanding transactions (block 760 ). A record of transactions that indicates currently outstanding transactions is used to compare the current requested transaction to see if its address matches with a transaction that is already being handled by the system 10 . Even if an exhaustive transaction list is not available for all addresses, a selected number of transactions may be recorded, such that a rapid determination may be made, whether a particular requested transaction is to be handled (block 770 ). Generally, an efficient transaction list may be used to compare the requested transaction within one clock cycle to make a fast determination whether a particular transaction is to be handled. The pipeline structure described above may be used to move each new transaction into a position in the pipeline, such that during virtually every clock cycle, a portion of the requested transaction is executed. Within a clock cycle of encountering the transaction, the system 10 may determine that there is an address match resulting from the transaction comparison. The matched address may then be sent to a local device and to the local coherency module 382 , which may look up the address in the coherence directory cache (block 780 ). The system 10 then prepares to execute the requested transaction. The target home agent 390 and any slave agents 394 may then execute at least a portion of the transaction (block 790 ). The home agent 390 and any slave agents 394 may then send responses to the request agent 392 that it looks up the nature of the transaction that is being referred to and completes the transaction to the requesting processor or I/O device, and then sends a further response back to the home agent 390 to have it unlock the transaction when the unlocking of the transaction is appropriate. For example, in order to read data from memory, the interchange between the home agent 390 , the slave agent 394 , and the requesting request agent 392 operates such that rather than having the home agent 390 maintain this transaction in a wait state, embodiments of the present invention provide for a protocol engine (e.g., the pipeline structure unit 393 ) that sends the transaction to a queuing structure. The requested transaction is then recycled back to the protocol engine at a later time, where there is a further step to be accomplished in the protocol. Meanwhile, on every intervening clock cycle, another transaction may be passed through the protocol cycle such that all clock cycles are utilized to move a requested transaction forward. Therefore, the bandwidth of the SSM protocol is increased and more efficient transactions in the system 10 may take place. Turning now to FIG. 8 , a block diagram depiction of the step of performing the request agent protocol indicated in block 710 of FIG. 7 is illustrated. The system 10 may look for transactions to be handled by the SSM protocol based upon a requested transaction (block 810 ). This function may be performed by the request agent 392 . The transaction is then acquired from a bus that interconnects the various components of the system 10 (block 820 ). Information regarding the transaction may then be recorded for later comparison with other requested transactions (block 830 ). The transaction is then sent to an appropriate home agent 390 for processing (block 840 ). The requested transaction may be sent to the switch 20 , which comprises a centerplane, such that the data regarding the transaction goes through the centerplane and then drives another coherency module 382 , but at the home agent 390 . At that position, it is queued up to determine whether the home agent 390 is ready to execute the transaction. A pipeline structure 393 is used such that for virtually every clock cycle a new transaction moves into each position of the pipeline to perform a portion of the requested transaction function, therefore it may be queued such that it may be recycled back to the protocol cycle at a later time. During this time, other intervening clock cycles are used to perform other transactions that are passed through the protocol cycle. Completion of the steps described in FIG. 8 substantially completes the process of performing the request agent protocol indicated in block 710 of FIG. 7 . For ease of illustration, several references to “cache line(s)” or “line(s)” are made in the discussion herein with respect to memory access. It should be appreciated that these references, as utilized in this discussion, may refer to any line that is cacheable, and include one or more bits of information that is retrieved from the caches 362 ( 1 −4) and/or memories 361 ( 1 −4) (see FIG. 3 ) in the system 10 . The various system layers, routines, or modules may be executable control units (such as control unit 389 (see FIG. 3 ). Each control unit 389 may include a microprocessor, a microcontroller, a digital signal processor, a processor card (including one or more microprocessors or controllers), or other control or computing devices. The storage devices referred to in this discussion may include one or more machine-readable storage media for storing data and instructions. The storage media may include different forms of memory including semiconductor memory devices such as dynamic or static random access memories (DRAMs or SRAMs), erasable and programmable read-only memories (EPROMs), electrically erasable and programmable read-only memories (EEPROMs) and flash memories; magnetic disks such as fixed, floppy, removable disks; other magnetic media including tape; and optical media such as compact disks (CDs) or digital video disks (DVDs). Instructions that make up the various software layers, routines, or modules in the various systems may be stored in respective storage devices. The instructions when executed by a respective control unit cause the corresponding system to perform programmed acts. Although the embodiments above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.

A method and apparatus for implementation of a pipeline structure for data transfer. A request is received from a first domain to access a second domain during a first clock cycle. A pipeline structure is used to perform at least a portion of the request during a subsequent clock cycle.

BACKGROUND [0001] Sealing devices are well known in the hydrocarbon recovery industry due to their ubiquitous use pursuant to varied needs throughout the wellbore. There are also many different types of sealing devices, some of which allow for testing immediately after setting by pressuring up on the well system to ensure that the setting procedure was successful. This is clearly beneficial as there is an immediate confirmation of a successful job. This occurs before the operator leaves the job site to insure that the job went well and thus promotes customer satisfaction. [0002] While the above testing opportunity is the case for many kinds of sealing devices it is not so for all devices. Swellable devices cannot be tested because their initial actuation is a much longer-term program. More specifically, swellable materials that are used in the wellbore generally set over a time period of about two weeks. While setting time does vary (due to particular fluid concentration and chemistry and the temperature of the wellbore at the location of the set), it is always over time long enough that it would be decidedly uneconomical to maintain testing equipment at a site to test such a seal after it is expected to be fully set. [0003] Because swellable materials have other beneficial properties and are favored in the art, they are becoming more and more prevalent despite the fact that testing is not realistically plausible. SUMMARY [0004] A swellable setting confirmation arrangement comprising a mandrel; a swellable material supported by the mandrel; one or more sensory configurations at the swellable material. [0005] A method for confirming setting of a swellable material comprising: running a swellable material to a target location in a wellbore; swelling the swellable material for a period of time; measuring strain caused by the swelling of the swellable material with one or more sensory configurations. [0006] A method for installing a swellable material having a setting confirmation function in a wellbore comprising: Installing one or more sensory configurations in a wellbore; installing a swellable material radially adjacent the one or more sensory configurations. BRIEF DESCRIPTION OF THE DRAWINGS [0007] Referring now to the drawings wherein like elements are numbered alike in the several Figures: [0008] FIG. 1 is a schematic view of a first embodiment of a set verification arrangement for a swellable device; [0009] FIG. 1A is an alternate configuration showing the sensory configuration in a spaced helical pattern; [0010] FIG. 1B is an alternate configuration showing the sensory configuration in a non-spaced helical pattern; [0011] FIG. 2 is a schematic view of a second embodiment of a set verification arrangement for a swellable device; [0012] FIG. 3 is a schematic view of a third embodiment of a set verification arrangement for a swellable device; and [0013] FIG. 4 is a schematic view of a fourth embodiment of a set verification arrangement for a swellable device. DETAILED DESCRIPTION [0014] The above-described drawback to the use of swellable devices in the downhole environment is overcome through various embodiments and methods as disclosed herein. [0015] Referring to FIG. 1 , a first embodiment is illustrated schematically in quarter section. A swellable setting confirmation arrangement 10 comprises a mandrel 12 having a swellable material 14 disposed there around. In one iteration, the swellable material 14 is around the mandrel 12 for 360 degrees but it should be noted that it is not necessarily required that the swellable material 14 be so configured. It is possible in other embodiments for the material 14 to be something short of 360 degrees about the mandrel 12 for particular applications without effect on the arrangement disclosed herein. Between the mandrel 12 and the swellable material 14 is disposed one or more sensory configuration(s) 16 . The configuration may comprise one or more optic fibers, load cells, strain sensors, such as hall effect sensors, momentary switches, etc. that have the ability to sense a load placed thereon (on or off, a “dichotomous measurement”). In one embodiment, the sensor(s) not only sense the presence of a load but additionally quantifies that load as well. The foregoing sensory configurations can be configured to sense quantitatively by known methods. Such sensing includes but are not limited to mercury strain gauges, rubber strain gauges, piezo resistance strain gauges, silicon strain gauges, wheatstone bridges, intrinsic sensors, extrinsic sensors, electro mechanical sensors, electro optic sensors, etc. An optic fiber based sensory configuration is an example of a configuration capable of both. The one or more sensory configurations 16 may thus be a single optic fiber, a plurality of fibers, a bundle of fibers, etc. extending roughly longitudinally and generally parallel to the mandrel 12 , or extending helically about the mandrel 12 (with the helix ranging from tightly wrapped (see FIG. 1B ) such that there is no gap between adjacent wraps of the optic fiber(s) to loosely wrapped (see FIG. 1 A) so that gaps from small to large may exist between the adjacent wraps of optic fiber(s)depending upon resolution desired). Determination of the density of the sensory configuration is directly related to the resolution of the information desired to be obtained. The greater the resolution desired, the greater the density needed. It is to be understood that the helical illustration of FIG. 1 is equally applicable to the FIG. 2 and FIG. 3 embodiments by substituting the configuration 16 in those illustrations for the configurations 16 shown in FIGS. 1A and 1B . It is intended that the reader understand that the helical conditions shown are applicable to any of the embodiments of the invention. [0016] In other embodiments, the one or more sensory configurations 16 may be placed randomly between the swellable material 14 and mandrel 12 or may be placed in any desired pattern between material 14 and mandrel 12 . This includes a pattern that is affected by the use of a network of strain sensors in a net of electrical connection, etc. The pattern may itself be unrelated to any anticipated distribution of strain (in which case the distribution is likely to be uniform but is not required to be) or may be specifically placed with regard to anticipated strain distribution. In either case, the purpose of the one or more sensory configurations 16 is to sense strain placed thereon by the swelling of the swellable material 14 . [0017] When a swellable material is set in a wellbore the material 14 will exert pressure against the mandrel 12 and the structure against which it is set. Depending upon a number of factors including but not limited to the degree of swelling attained and the geometric shape of the structure in which the swellable device is being set, the strain experienced at various portions of the swellable material and thus the mandrel may be different. The swellable setting confirmation arrangement 10 provides information to this effect to an operator. As noted above, since the swellable material swells slowly in the wellbore, on the order of two weeks, there is no way to test the set of the swellable while the installation crew and equipment is still on site. This means that if the swellable did not attain a set that enables it to do its job, this will not necessarily be known and presumably, production will suffer. If a well operator knows that something was a miss, remedial action could be taken. Where the arrangement 10 merely shows existence or absence of strain enough information is provided that the operator knows the device must be pulled and a new one put in. Where however, the arrangement 10 also provides a quantification of the strain thereon, a much more resolute picture of the downhole environment can be gleaned. This enables an operator or swellable installation crew to determine more precisely what type, shape, style, etc. of swellable would be best suited to have the desired effect in the particular wellbore. This is possible because with a quantification of strain, the geometry in the wellbore is far better defined since areas of greater strain and areas of lesser strain will indicate washed out areas or out of round areas of the structure downhole in which the device is being set. [0018] In the embodiments discussed above, as the swellable material swells into contact with a structure in which it is being set, the material 14 itself exerts more and more pressure on the mandrel. Because the one or more sensory configurations 16 are located between the material 14 and the mandrel 12 , they are compressed there between and hence will register that condition either dichotomously or quantitatively depending upon application. [0019] In another embodiment illustrated in FIG. 2 , the one or more sensory configurations 16 are embedded in the swellable material 14 . The one or more sensory configurations are hence put into compression upon swelling of the swellable material 14 similarly to that of the embodiment of FIG. 1 but the compression profile is distinct in that the configurations 16 are not directly compressed against the mandrel 12 . While the magnitude of compression may be smaller in this embodiment, it is still easily measured dichotomously or quantitatively. Further, in this embodiment the one or more sensory configurations may be better environmentally protected for some applications. [0020] In yet another embodiment, referring to FIG. 3 , the one or more sensory configurations 16 are located on an outside surface 20 of the material 14 . In this embodiment, the configurations 16 are exposed to the wellbore and are more likely to experience damage but they also will be directly in contact with the surface against which the swellable material 14 is to be set. This will provide a very accurate indication of the surface irregularities of the structure in applications where such is useful. [0021] In yet another embodiment, referring to FIG. 4 , the one or more sensory configurations 16 (each of those disclosed above are possible) are separated from the swellable material 14 . In one iteration the separated sensory configurations are still mounted to the same mandrel so that they can be put in place in a single run whereas in another iteration, the sensory configurations 16 could be mounted to a separate string for run in separately from the swellable material 14 if dictated by a particular need. FIG. 4 schematically illustrates both concepts by including a break line 26 that is intended to signify alternatively length of the mandrel 12 or a separate mandrel run at a different time. In either of these iterations, the one or more sensory configurations 16 are mountable in the wellbore 22 via a deployment method such as expansion. One embodiment will use rings 28 and 30 on either end of the configurations 16 that are expandable and will anchor the configurations 16 to the wellbore 22 . The configurations 16 are thus affixed to the wellbore 22 where after the swellable material 14 is positioned inside of the configuration(s) 16 and allowed to swell in the normal course. Progress of the swellable material can be monitored, as can that of the foregoing embodiments through the one or more sensory configurations 16 . It is also to be noted that the components can be reversed such that the configurations 16 are placed at a radially inward position instead of outward with similar effects. [0022] While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation

A swellable setting confirmation arrangement comprising: a mandrel; a swellable material supported by the mandrel; one or more sensory configurations at the swellable material and a method for confirming setting of a swellable material and for installing a swellable material having a setting confirmation function.

GOVERNMENT SUPPORT Experimental work described herein was supported by grants from the United States Government which may have certain rights in the invention. BACKGROUND OF THE INVENTION Transmembrane receptors are proteins which are localized in the plasma membrane of eukaryotic cells. These receptors have an extracellular domain, a transmembrane domain and an intracellular domain. Transmembrane receptors mediate molecular signaling functions by, for example, binding specifically with an external signaling molecule (referred to as a ligand) which activates the receptor. Activation results typically in the triggering of an intracellular catalytic function which is carried out by, or mediated through, the intracellular domain of the transmembrane receptor. There are various families of transmembrane receptors that show overall similarity in sequence. The highest conservation of sequence is in the intracellular catalytic domain. Characteristic amino acid position can be used to define classes of receptors or to distinguish related family members. Sequences are much more divergent in the extracellular domain. A variety of methods have been developed for the identification and isolation of transmembrane receptors. This is frequently a straightforward matter since receptors often share a common sequence in their catalytic domain. However, the identification of the ligands which bind to, and activate, the transmembrane receptors is a much more difficult undertaking. Brute force approaches for the identification of ligands for known receptors are rarely successful. Brute force approaches usually depend on a biological activity that can be monitored (e.g., nerve growth for nerve growth factor; or glucose homeostasis for the insulin receptor) or they depend on finding a source of the ligand and using affinity to purify it (as was used to find the c-Kit ligand in mouse hemopoietic cells). In general, however, a source of the ligand is not known, nor is there an obvious or easily assayable biological activity. Therefore, there are many receptors, referred to as "orphan receptors" for which no corresponding ligand has been identified. A systematic approach to the identification of receptor ligands would be of great value for the identification of ligands having useful pharmacological activities. SUMMARY OF THE INVENTION The present invention relates to compositions and methods which are useful in connection with the identification of transmembrane receptors and their corresponding ligands. Preferred transmembrane receptors include tyrosine kinase receptors, cytokine receptors and tyrosine phosphatase receptors. Such receptors mediate cell signaling through the interaction of specific binding pairs (e.g., receptor/ligand pairs). The present invention is based on the finding that an unknown component in a receptor-mediated signaling pathway, which results ultimately in an intracellular catalytic event, can be identified by combining other known components within a cellular background within which the catalytic event ordinarily will not take place at significant levels. A cDNA expression library is then used to transform such cells. If the cDNA insert encodes the missing component of the transmembrane receptor-mediated signaling pathway, the catalytic event will be triggered. Detection of the otherwise absent catalytic activity is indicative of a cDNA insert encoding the missing component. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating the steps employed in the identification of a ligand specific for the FGF receptor. FIG. 2 is a diagram illustrating the colony Western blot technique. DETAILED DESCRIPTION OF THE INVENTION Transmembrane receptors have a binding site with high affinity for a specific signaling molecule. The signaling molecule is referred to herein as a ligand. The present invention is based on the development of a novel approach for the identification of polypeptide ligands by functional expression in the yeast Saccharomyces cerevisiae. This approach is based on the previously unproven hypothesis that it may be possible to functionally express a heterologous tyrosine kinase receptor and its corresponding polypeptide ligand in the same yeast cell, leading to the activation of the receptor and a substantial increase in intracellular tyrosine phosphorylation. The intracellular tyrosine kinase activity of the tyrosine kinase receptor is activated by the binding of a ligand to the extracellular domain of the receptor. This interaction can occur on the surface of the cell (plasma membrane) or in intracellular membrane compartments such as secretory vesicles. In either case, according to the hypothesis confirmed herein, the activation of the cytoplasmically oriented kinase domain results in phosphorylation of tyrosine residues of cytoplasmic protein targets. Yeast was chosen as an expression system because many molecular biological techniques are available and it has been demonstrated that many higher eukaryotic genes, including some growth factor-encoding genes, can be functionally expressed in yeast. In addition, only a few endogenous protein tyrosine kinases have been identified in yeast, so that yeast is expected to have a low background of endogenous tyrosine phosphorylation. These features enabled the development of a screen to identify polypeptide ligands for heterologous tyrosine kinase receptors for which no ligand has yet been identified. Such receptors are referred to as orphan receptors. The term heterologous is used herein to mean "non-endogenous". Thus, for example, a tyrosine kinase which is heterologous in the yeast Saccharomyces cerevisiae is a tyrosine kinase which is non-endogenous (i.e., not present) in wild-type Saccharomyces cerevisiae. The disclosed method for identifying a ligand for a tyrosine kinase receptor involves the co-expression in yeast cells (preferably Saccharomyces cerevisiae) of a gene encoding a tyrosine kinase receptor, together with an expression cDNA library which, for example, is constructed from a tissue or cell line that is thought to synthesize a receptor ligand in vivo. The tyrosine kinase gene, together with any regulatory elements required for expression, can be introduced into the yeast strain on a stable plasmid (e.g., a CEN-based plasmid), or it can be integrated into the yeast chromosome using standard techniques (Methods In Enzymology, vol. 194, C. Guthrie and G. Fink, eds., (1991)). The choice of expression vectors for use in connection with the cDNA library is not limited to a particular vector. Any expression vector suitable for use in yeast cells is appropriate. The discussion relating to experiments disclosed in the Exemplification section which follows describes a particular combination of elements which was determined to yield meaningful results. However, many options are available for genetic markers, promoters and ancillary expression sequences. As discussed in greater detail below, the use of an inducible promoter to drive expression of the cDNA library is a preferred feature which provides a convenient means for demonstrating that observed changes in tyrosine kinase activity are, in fact, cDNA dependent. In a preferred format of the assay, two expression constructs are employed; the first expression construct contains the tyrosine kinase gene and the second expression construct carries the cDNA library. Typically the two expression constructs are not introduced simultaneously, but rather a stable yeast strain is first established which harbors the tyrosine kinase receptor carried on a CEN-based plasmid. Other regulatory sequences are included, as needed, to ensure that the tyrosine kinase gene is constitutively expressed. A CEN-based expression vector contains CEN sequences which are specific centromeric regions which promote equal segregation during cell division. The inclusion of such sequences in the expression construct results in improved mitotic segregation. It has been reported, for example, that mitotic segregation of CEN-based plasmids results in a population of cells in which over 90% of the cells carry one to two copies of the CEN-based plasmid. Faulty mitotic segregation in a similar transformation experiment with an otherwise identical expression construct which lacks CEN sequences would be expected to result in a cell population in which only about 5-20% of the cells contain the plasmid. Many transmembrane tyrosine kinase receptors have been identified (for reviews see, e.g., Hanks, Current Opinion in Structural Biology 1: 369 (1991) and Pawson and Bernstein, Trends in Genetics 6:350 (1990)). A number of these tyrosine kinase receptors are orphan receptors for which no activating ligand has been identified. Any transmembrane tyrosine kinase that can be expressed in yeast cells is useful in connection with the present invention. Based on fundamental principles of molecular biology, there is no reason to believe a priori that any member of the tyrosine kinase receptor family would not be useful in connection with the present invention. Preferably, the gene encoding the tyrosine kinase receptor is isolated from the same organism from which nucleic acid is to be isolated for use in the construction of a cDNA library. As discussed in the Exemplification section which follows, the level of expression of the transmembrane tyrosine kinase is a variable which must be considered in the design of the assay for ligand identification. For example, it was determined that high level expression of the FGF receptor results in a substantial increase in intracellular phosphorylation, even in the absence of FGF. Therefore, it is important that expression of the transmembrane receptor be driven by regulatory elements which result in a sufficient level of expression of the transmembrane receptor to facilitate detection following activation of the receptor by ligand binding, while not resulting in overexpression to the extent that ligand-independent autophosphorylation results. A preferred promoter for the expression of the transmembrane receptor is the ACT1 (actin) promoter. This promoter was determined to provide a robust, ligand-dependent signal in the experiments described below. The cDNA library is prepared by conventional techniques. Briefly, mRNA is isolated from an organism of interest. An RNA-directed DNA polymerase is employed for first strand synthesis using the mRNA as template. Second strand synthesis is carried out using a DNA-directed DNA polymerase which results in the cDNA product. Following conventional processing to facilitate cloning of the cDNA, the cDNA is inserted into an expression vector suitable for use in yeast cells. Preferably the promoter which drives expression from the cDNA expression construct is an inducible promoter (e.g., GAL1) . As disclosed in the Exemplification section that follows, removal of the endogenous signal sequence from a cDNA insert encoding a functional receptor ligand resulted in inactivation of the ligand. It appears, therefore, to be necessary to include a signal sequence in the cDNA library constructs to mark the encoded polypeptide for transport across the membrane of the endoplasmic reticulum thereby enabling the extracellular release of the encoded polypeptide which facilitates interaction with the extracellular domain of a transmembrane receptor. The signal sequence employed in the experiments disclosed herein was the signal sequence of Saccharomyces cerevisiae invertase. However, any signal sequence which can function in yeast should be useful in connection with the present invention (Nothwehr and Gordon, Bioessays 12:479 (1990)). The cDNA expression library is then used to transform the yeast strain which constitutively expresses the transmembrane tyrosine kinase gene. mRNA encoding the tyrosine kinase receptor and the cDNA product are thought to be translated in the rough endoplasmic reticulum, accumulate in the inner cavity of the rough endoplasmic reticulum, and migrate to the lumen of the Golgi vesicles for transport to the Golgi complex. Within the Golgi complex, proteins are "addressed" for their ultimate destination. From the Golgi complex, the addressed proteins are transported out of the complex by secretory vesicles. A transmembrane tyrosine kinase receptor, if sequestered in a secretory vesicle, the Golgi complex or the endoplasmic reticulum, is oriented such that the cytoplasmic domain is in contact with the cellular cytoplasm as the various vesicles migrate from the Golgi complex to the plasma membrane which is the ultimate destination for a transmembrane receptor. It is possible that the signal sequence bearing polypeptides encoded by the cDNA library can be co-compartmentalized with the transmembrane receptor in the same secretory vesicle. If this were to occur, any cDNA encoded ligand specific for the tyrosine kinase receptor could bind with the "extracellular" portion of the tyrosine kinase receptor (which is located in the internal portion of the secretory vesicle during the migration to the plasma membrane) thereby activating intracellar tyrosine kinases through contact with the cytoplasmically oriented intracellular domain of the tyrosine kinase receptor. Alternatively, activation of intracellular tyrosine kinase activity could also result from interaction with an extracellular polypeptide encoded by the cDNA library through interaction with a plasma transmembrane tyrosine kinase receptor. This occurs, for example, following migration of the secretory vesicle to the plasma membrane resulting in the incorporation of the plasma transmembrane tyrosine kinase receptor and export of the signal sequence-bearing cDNA encoded polypeptide ligand. In either case, activation of the intracellular tyrosine kinase activity results in the phosphorylation of intracellular tyrosine residues at a level which is substantially higher (i.e., at least about 4-fold higher) than background levels of phosphorylation in the yeast stain harboring an expression construct containing only the gene encoding the tyrosine kinase receptor (the negative control strain). The preferred method for determining the level of intracellular tyrosine phosphorylation is a colony Western blot using replica plates. It will be recognized that, although particularly convenient, the colony Western blot method is but one example of many conventional assays which could be employed to determine levels of intracellular tyrosine kinase activity. The colony Western blot procedure using replica plates is shown diagramatically in FIG. 2. cDNA library transformants are initially plated on media which do not contain an inducer of the promoter which drives expression of the cDNA insert. For examples, if the GAL1 promoter is used to drive expression of the cDNA insert, cDNA library transformants are initially plated on a medium containing 2% glucose. On this growth medium, cells containing the cDNA expression construct will grow, but the encoded cDNA product is not expressed. A set of replica filters is produced from the initial transformation plate by sequentially placing a set of directionally oriented membranes (e.g., nitrocellulose filter membranes) over the transformation plate such that the membrane contacts existing transformant colonies. Cells from transformation colonies adhere to the membranes to form a pattern which represents the pattern of colonies on the transformation plate. Each of the replica filters is then placed on a separate plate, one of which contains a compound which will induce the inducible promoter (e.g., 2% galactose to induce the GAL1 promoter) and one of which will not induce the inducible promoter (e.g., 2% glucose for the GAL1 promoter). Both plates are incubated overnight to promote regrowth of the original cDNA library transformants. Following overnight incubation, the replica filters are removed from the growth medium plates, and the colonies are lysed in situ by soaking the replica filters in a lysis solution for a period of time sufficient to lyse cellular membranes (e.g., 0.1% SDS, 0.2 N NaOH, 35 mM DTT for about 30 minutes). The replica filters are then probed with anti-phosphotyrosine antibodies. Colonies which exhibit elevated tyrosine kinase activity on the replica filter which had been incubated overnight on a growth medium containing a compound which induces expression-of the cDNA insert linked to the inducible promoter, but which do not exhibit elevated tyrosine kinase activity on the replica filter incubated overnight on a growth medium lacking the inducing compound, contain a cDNA insert encoding a candidate ligand. To confirm that a candidate ligand is, in fact, a ligand (and not, for example, a distinct tyrosine kinase), the expression construct is recovered (or rescued) from the cells of the colony demonstrating increased tyrosine kinase activity when grown under inducing conditions. The rescued expression construct is then used to transform a first yeast strain which is known to constitutively express the tyrosine kinase gene, and a second yeast strain which does not express the tyrosine kinase gene. Increased tyrosine kinase activity in the strain which is known to express the tyrosine kinase gene, coupled with no increased tyrosine kinase activity in the strain which does not express the tyrosine kinase gene, serves as confirmation that the cDNA insert of the cDNA expression construct encodes a polypeptide ligand which binds to, and activates, the tyrosine kinase gene product. Following confirmation that the candidate ligand is, in fact, a receptor ligand, it is a straightforward matter to identify and characterize the polypeptide encoded by the cDNA library which is responsible for the increase in tyrosine kinase activity. This is accomplished by isolating plasmid DNA from the strain which exhibits the elevated tyrosine kinase activity and characterizing the insert carried in the plasmid (e.g., by DNA sequence analysis). The molecule encoded by the cDNA insert can then be further characterized by conventional approaches such as expression and isolation of the encoded polypeptide followed by in vitro binding studies in order to confirm the specificity of the binding interaction with the transmembrane receptor. The method of the present invention is not limited to the isolation of tyrosine kinase receptor ligands. Rather, the method can be modified for use in the identification of ligands for any transmembrane receptor having a single transmembrane domain, an extracellular domain and an intracellular domain. This is accomplished by generating an expression construct encoding a chimeric fusion protein comprising the extracellular domain of a transmembrane receptor fused to the intracellular domain of a specific tyrosine kinase receptor (e.g., the FGF receptor). As mentioned previously, this construct is preferably generated in a CEN-based plasmid background or, alternatively, in a plasmid which will facilitate integration of the chimeric receptor into the yeast chromosome. Conventional molecular biological techniques are employed to generate this construct, as well as all others disclosed in this specification (see e.g., Molecular Cloning: A Laboratory Manual, Maniatis et al., eds., Cold Spring Harbor Publications, Cold Spring Harbor, N.Y. (1989)). This expression construct encoding the tyrosine kinase receptor fusion protein is used in a manner analogous to the expression construct encoding the tyrosine kinase receptor in the embodiment described above. Briefly, the preferred embodiment of this aspect of the invention includes the construction of a yeast strain which constitutively expresses a chimeric fusion protein of the type described above. This strain is then transformed with a cDNA expression library generated using mRNA isolated from the organism of interest. A ligand which binds specifically to the native transmembrane receptor will bind to the extracellular domain of the tyrosine kinase fusion protein and this ligand binding will trigger ligand-dependent intracellular tyrosine kinase activity mediated by the intracellular domain of the tyrosine kinase receptor. Intracellular tyrosine kinase activity is detected in the manner described previously. A specific example of this embodiment of the present invention is applicable to the isolation of a ligand for a cytokine receptor (e.g., erythropoietin receptor, interleukin-3 receptor, etc.). Cytokine receptors, like tyrosine kinase receptors, are transmembrane receptors found in mammalian cells and possess both an extracellular domain and an intracellular domain. However, unlike the tyrosine kinase receptors, cytokine receptors do not possess a catalytic domain but rather recruit cytoplasmic tyrosine kinase enzymes in response to ligand activation. More specifically, the intracellular (cytoplasmic) domain of the cytokine receptor has been shown to bind to, and activate, a class of cytoplasmic tyrosine kinases (e.g., the JAK2/TYK2 class). To isolate cytokine receptor ligands, a yeast strain is constructed which constitutively expresses a cytoplasmic tyrosine kinase and a transmembrane cytokine receptor. This yeast strain is then transformed with a cDNA expression library from an organism of interest, preferably under the control of an inducible promoter. Elevated levels of tyrosine kinase activity will be observed if the polypeptide encoded by the cDNA library insert functions as a ligand for the native cytokine receptor. Binding of the polypeptide ligand to the extracellular domain of the cytokine receptor (either at the plasma membrane or within a secretory vesicle) results in the activation of the cytoplasmic tyrosine kinase. The colony Western blot procedure discussed above, and shown diagramatically in FIG. 2, is the preferred method for screening for an expression construct encoding a functional ligand. Specifically, a set of replica filters is prepared from the original transformation plate and the first and second replica filters are incubated overnight under inducing conditions, and non-inducing conditions, respectively. Colonies affixed to the replica filters are then lysed and probed with antiphosphotyrosine antibodies. Increased levels of tyrosine kinase activity can be indicative of a cDNA insert encoding a ligand for the cytokine receptor or, alternatively, a cDNA insert encoding a cytoplasmic tyrosine kinase enzyme. To determine which of these two alternatives is responsible for the observed increase in tyrosine kinase activity, the expression construct encoding the candidate ligand is rescued and used to independently transform a first cell population which constitutively expresses the cytokine receptor and the cytoplasmic tyrosine kinase, and a second cell population which constitutively expresses the cytokine receptor but not the cytoplasmic tyrosine kinase. Candidates which demonstrate an increase in tyrosine kinase activity in the first cell population, but not the second, encode a cytokine receptor ligand. Expression constructs which result in an increase in tyrosine kinase activity in both the first cell population and the second cell population encode a cytoplasmic tyrosine kinase. Given the fundamental disclosure that a yeast cell system can be used to identify ligands and other members of specific binding pairs involved in receptor-mediated molecular signaling, numerous variations of the theme described above are derivable through routine experimentation. Using such variations, any single polypeptide component of the receptor-mediated signaling pathway can be identified through the introduction of a cDNA library into yeast cells which have been modified to constitutively produce other necessary components of the signaling pathway. For example, the methods described above can be modified to facilitate the identification of a cytokine receptor. As discussed above, cytokine-receptor mediated signaling involves a cytokine receptor and a cytoplasmic tyrosine kinase which is activated by interaction with the cytoplasmic domain of the cytokine receptor. As reported in the Exemplification section below, overexpression of the transmembrane tyrosine kinase (e.g., by expression from the GAL1 promoter) resulted in ligand-independent tyrosine kinase activity. By analogy, it would be expected that overexpression of a transmembrane cytokine receptor in the presence of a cytoplasmic tyrosine kinase would yield ligand-independent tyrosine kinase activity. More specifically, a yeast strain constitutively expressing a cytoplasmic tyrosine kinase is first constructed. The use of the GAL1 promoter would be expected to result in a high level of cytoplasmic tyrosine kinase expression. However, routine experimentation may be required to optimize the expression level. It is preferred, for example, that the cytoplasmic tyrosine kinase be produced at such a level that it is detectable by Western blot. A cDNA library is then constructed, preferably with the expression of the cDNA insert under the control of an inducible promoter. Replica filters are produced and incubated independently with, and without, a compound capable of inducing expression from the inducible promoter. Increased levels of tyrosine kinase activity are detected, for example, by colony Western blot in cells grown under inducing conditions, but not under non-inducing conditions. This would be observed, for example, when the cDNA insert encodes a cytokine receptor. The expression construct is rescued from these cells and introduced independently into yeast cells with, and without, constitutively expressed intracellular tyrosine kinase. Increased tyrosine kinase activity which is dependent upon the constitutively expressed cytoplasmic tyrosine kinase of the host strain indicates that the cDNA insert encodes a cytokine receptor. Increased tyrosine kinase activity which is not dependent upon the constitutively expressed cytoplasmic tyrosine kinase of the host strain is an indication that the cDNA insert encodes a functional tyrosine kinase. If such a cytokine receptor is known or discovered, yeast strains expressing the cytoplasmic tyrosine kinase and the cytokine receptor can be employed in a method for the isolation of a ligand in a manner analogous to the methods described elsewhere in this specification. Another example of a variation of presently disclosed method is useful for the identification of a receptor for an orphan polypeptide ligand (i.e., a ligand for which no receptor has been previously identified), or for the identification of new receptors for a ligand which is known to interact productively with one or more previously identified receptors. This method incorporates the use of a yeast strain which has been modified to constitutively produce the previously identified ligand or orphan ligand. A cDNA library is introduced and the colony Western blot is employed to identify colonies which exhibit increased tyrosine kinase activity in the induced state. Rescue of the expression construct, followed by retransformation of yeast cells both with and without a constitutively expressed ligand, is used to confirm ligand-dependent activation of tyrosine kinase activity. It will be recognized that the description above relates specifically to a tyrosine kinase-like receptor. The method is easily modified for use with a cytokine receptor by adding constitutive cytoplasmic tyrosine kinase activity to the list of constitutive host cell requirements. Similarly, the methods of this invention can be used to identify a cytoplasmic tyrosine kinase if a known cytokine receptor and ligand are provided. In this method, the cytokine receptor and ligand are expressed constitutively in a host yeast strain. The cDNA library is provided, and transformants are screened, in the induced and non-induced state, by the replica method discussed above. Candidate cytoplasmic tyrosine kinases are those encoded by an expression construct conferring increased tyrosine kinase activity in the induced state. The cDNA expression construct is rescued from the identified colony and introduced into yeast cells which constitutively express the cytokine receptor and ligand. The rescued construct is also introduced into a yeast strain lacking the cytokine receptor and ligand. Increased activity in the former, but not in the latter, is indicative of a cDNA insert encoding a cytoplasmic tyrosine kinase. In another aspect of the invention, polypeptide modulators of receptor-mediated tyrosine kinase activity can be isolated. A polypeptide modulator can be, for example, a polypeptide (intracellular or extracellular) which modifies the affinity of the ligand for receptor, or which modifies the activity of the catalytic domain (either integral or recruited). Polypeptide modulators can be isolated by first providing a yeast strain which constitutively expresses a ligand/receptor pair (together with the cytoplasmic tyrosine kinase in the case of a cytokine receptor/ligand pair). The construction of such strains has been discussed in greater detail above. A yeast cell which constitutively expresses the ligand/receptor pair is expected to exhibit a relatively high level of background tyrosine kinase activity when the cDNA library is expressed in both the induced and non-induced state. However, the presence of a cDNA insert encoding a strong modulator (either an up-modulator or a down-modulator) will be determined by a detectable (i.e., at least about 2-fold) change in the level of tyrosine kinase activity in the induced state due to the presence of the polypeptide modulator. In another aspect of the invention, ligands which specifically activate transmembrane tyrosine phosphatase receptors can be isolated. Transmembrane tyrosine phosphatase receptors are membrane components which have an intracellular catalytic domain which functions to remove phosphate groups from tyrosine residues. In other words, the tyrosine phosphatase receptor function can be viewed as a catalytic function which reverses the action of a tyrosine kinase (a tyrosine kinase functions by adding a phosphate group to intracellular tyrosine residues). Tyrosine phosphatase receptors have an extracellular domain and, therefore, the existence of extracellular ligands is presumed although none have been isolated to date. In order to isolate a cDNA fragment encoding a tyrosine phosphatase receptor ligand, it is necessary to first provide a yeast strain which constitutively expresses cellular components necessary to produce a basal level of intracellular tyrosine kinase activity. This can be accomplished, for example, by providing a strain which constitutively expresses appropriate levels of a transmembrane tyrosine kinase receptor, together with its corresponding ligand. Basal levels of tyrosine kinase activity in such a strain are determined using the colony Western blot, for example. Following a determination of intracellular tyrosine kinase activity, this strain is further modified to express a tyrosine phosphatase receptor. Subsequent to the introduction of the tyrosine phosphatase receptor gene, levels of tyrosine kinase activity are again determined to ensure that there has been no change in the basal level of phosphorylation detected. In the absence of the tyrosine phosphatase receptor ligand, the addition of the expressible tyrosine phosphatase receptor gene to the strain should not affect basal levels of phosphorylation. Confirmation that the introduction of the tyrosine phosphatase gene does not affect detected phosphorylation levels is followed by the introduction of a cDNA library, preferably under the control of an inducible promoter. Replica filters are produced from the plate of transformants and incubated overnight under either inducing or non-inducing conditions. The levels of intracellular tyrosine phosphorylation are then determined, for example, by the colony Western blotting procedure. Reduced levels of intracellular tyrosine phosphorylation under inducing growth conditions, relative to the levels determined under non-inducing growth conditions, are an indication that the cDNA insert encodes a tyrosine phosphatase ligand which binds to the extracellular domain of the tyrosine phosphatase receptor thereby activating the tyrosine phosphatase activity which functions to reduce intracellular tyrosine phosphorylation thereby reversing the effect of the constitutively expressed tyrosine kinase. The initial indication that the cDNA insert encodes a tyrosine phosphatase ligand can be confirmed by further studies including, for example, demonstration that the observed decrease in phosphorylation is dependent upon entry of the cDNA encoded product into the secretory pathway. Confirmation that a signal sequence is encoded by the cDNA insert is an example of one type of confirmatory experiment. The methods of the present invention can be further modified for use in the identification of functionally significant domains in a transmembrane receptor or its ligand. This method is carried out, for example, by mutagenizing either the transmembrane receptor or its ligand by conventional site-directed mutagenic techniques. The mutagenized component is then included in an assay of the type described above with a non-mutagenized copy serving as a positive control. Increased intracellular tyrosine phosphorylation in the positive control coupled with a relative decrease in tyrosine phosphorylation (relative to the positive control) in the assay which includes the mutagenized component indicates that the mutagenized amino acid residue(s) are of functional significance. EXEMPLIFICATION Disclosed in this Exemplification section are experiments which confirm a previously unproven hypothesis that it may be possible to functionally express a tyrosine kinase receptor and its corresponding polypeptide ligand in the same yeast cell, leading to activation of the receptor and a substantial increase in intracellular tyrosine phosphorylation. More specifically, using African clawed frog Xenopus laevis FGF receptor and FGF genes as a model system, it has been demonstrated that tyrosine kinase activity is triggered by co-expression of its ligand gene in yeast cells, provided that the ligand is capable of entering the secretory pathway. This activation of FGF receptor was detected by colony Western blotting which enables the screening of a large number of yeast transformants of a cDNA library. By screening a Xenopus cDNA library with a yeast strain expressing FGF receptor, two genes encoding novel growth factor-like ligands were identified, which can activate the FGF receptor by conventional pathways. Materials and Methods i) Yeast strains A yeast Saccharomyces cerevisiae strain used in this study was PSY315 (Mat a, leu2, ura3 his3, lys2). ii) Yeast transformation and media The LiCl method (Ito et al., J. Bacteriol. 153:167 (1983)) was used for yeast transformation. Following media were used for yeast culture, YPD (1% yeast extract, 2% tryptone, 2% glucose), YPG (1% yeast extract, 2% tryptone, 2% galactose), SD (0.067% yeast nitrogen base w/o amino acids, 2% glucose), and SG (0.067% yeast nitrogen base w/o amino acids, 2% galactose). iii) Plasmids The vector plasmids pTS210 and pTS249 carry URA3 and LEU2, respectively, and both carry CEN4, GAL1 promoter and ACT1 terminator. The plasmid pKNA1 harbors LEU2, CEN4, ACT1 promoter and ACT 1 terminator. Two types of plasmids for expression of Xenopus bFGF (basic fibroblast growth factor) in yeast were constructed: One plasmid is constructed by cloning bFGF gene into pTS210 (pTS-FGF) and a second plasmid is identical to the first except that a signal sequence of S. cerevisiae invertase (Carlson et al., Mol. Cell. Biol. 3: 439 (1983)) was inserted at the initiation codon of the bFGF gene (pTS-ssFGF). For FGF receptor expression, the Xenopus FGF receptor-1 gene (Musci et al., Proc. Natl. Acad. Sci. USA 87:8365 (1990)) was cloned into pTS249 and pKNA1 (pTS-FGFR and pKN-FGFR, respectively). iv) Antibody Anti-phosphotyrosine antibody 4G10 is purchased from Upstate Biotechnology Incorporated. v) Colony Western blotting Yeast transformants were plated on SD plates and incubated at 30° C. for two days. Colonies were transferred onto two nitrocellulose membranes (Millipore HATF 082). These membranes were placed colony-side up on SD and SG plates, and incubated overnight at 30° C. The membranes were placed on Whatman 3 MM filter paper presoaked with lysis buffer (0.1% SDS, 0.2 M NaOH, 35 mM DTT), and incubated at room temperature for 30 min. Colonies on the membranes were rinsed off with water, then the membranes were incubated in TBS-T(20 mM Tris-HCl pH 8.0, 150 mM NaCl, 0.05% Tween-20)-2% BSA (sigma) for blocking on a shaker for one hour, then incubated in 1:1,000-diluted anti-phosphotyrosine antibody (in TBS-T with 2% BSA) for one hour, and subsequently washed three times in TBS-T. The blots were then incubated in 1:10,000-diluted HRP(horse radish peroxidase)-conjugated goat anti-mouse Ig antibody (Bio-Rad) for one hour, and washed three times. Detection was done with chemiluminescence reagents (Amersham, ECL). vi) cDNA library The vector plasmid of the cDNA library is λyes (Elledge et al., Proc. Natl. Acad. Sci. USA 88: 1731 (1991)), which carries URA3, CEN4, ARS1, GAL1 promoter and HIS3 terminator. Two sources of cDNA were used for library construction. One was made from Xenopus XTC cells, The other was made from Xenopus unfertilized eggs and 10 hour embryos. vii) Ca 2+ release assay The procedure for the Ca 2+ release assay described in Amaya et al. (Cell 66:257 (1991)) was followed. Briefly, oocytes injected with certain mRNAs transcribed in vitro were incubated for two days, then incubated with 45 Ca 2+ for three hours. These oocytes were washed in 45 Ca 2+ -free medium, incubated in media for 10 minutes, followed by scintillation counting of the released radioactivity. viii) Partial purification of EG2 protein Yeast cells expressing the EG2 gene under control of GAL promoter were cultured in 1 L of YPG for eight hours (about 2×10 10 cells). Cells were collected and disrupted with glass beads in 20 ml of buffer A (20 mM Tris-HCl (pH 8.0), 1 mM EDTA, 1 mM PMSF), containing 150 mM NaCl. Cell debris were removed by low speed centrifugation (3,000×g for 5 minutes). The supernatant was centrifuged at 80,000×g for 20 minutes. The pellet was suspended in 5 ml of buffer A containing 1.2 M NaCl, then centrifuged with the same condition. The resulting pellet was suspended in 2 ml of buffer A containing 1% Triton X-100, and centrifuged with the same condition again. The supernatant was diluted 20 fold in modified Barth's saline (Gurdon, Meth. Cell Biol. 16: 125 (1977)) containing 0.5 mg/ml BSA. Results and Discussion To test whether co-expression of a receptor-tyrosine kinase and its ligand leads to the activation of the kinase in yeast cells, Xenopus laevis FGF receptor and bFGF were used as a model system. These genes were co-expressed in yeast cells under control of GAL1 promoter by co-transforming pTS-FGFR and pTS-FGF. In addition, bFGF fused with the SUC2 signal sequence (pTS-ssFGF) was also co-expressed with the FGF receptor gene because it is known that the bFGF gene does not have a signal sequence. To determine whether the tyrosine kinase is activated in these strains, whole cell extracts were analyzed by immunoblotting with anti-phosphotyrosine antibody. The following results were obtained: (1) Expression of either bFGF or ssFGF alone had no effect on the level of tyrosine phosphorylation. (2) Expression of the FGF receptor plasmid led to a substantial increase in tyrosine phosphorylation of several endogenous proteins. (3) Co-expression of FGF receptor and ssFGF dramatically increased tyrosine phosphorylation to a level that was several times higher than the phosphorylation level observed after expression of the FGF receptor alone. (4) Co-expression of the FGF receptor and bFGF without a signal sequence did not lead to any increase in phosphorylation above that obtained after expression of the FGF receptor alone, although the same levels of the FGF proteins in the strains expressing the bFGF gene with and without the signal sequence are detected by immunoblotting with anti-FGF antibody. FGF could not be detected in culture supernatants, suggesting that the interaction was intracellular or periplasmic. These findings demonstrate that it is possible to functionally co-express the FGF receptor and bFGF in yeast in such a way that they can interact productively in an autocrine manner and thereby lead to an increase in the FGF-receptor mediated phosphorylation of endogenous yeast proteins. bFGF with a signal sequence appears to interact with the extracellular domain of the FGF receptor on the cell surface or in internal membrane compartments, while bFGF without a signal sequence localizes in the cytoplasm and cannot interact with the receptor. For screening of a large number of yeast transformants, a colony Western blotting method (Lyons and Nelson, Proc. Natl. Acad. Sci. USA 81:7426 (1984)) was developed. Yeast transformants expressing bFGF (with or without the signal sequence) and/or FGF receptor were plated on a glucose plate. Colonies were transferred to a filter and the filter was then placed on a galactose plate to induce bFGF expression. After overnight incubation, cells on the filter were lysed and the level of tyrosine phosphorylated proteins in each colony was determined by probing with anti-phosphotyrosine antibodies. The results of this experiment were essentially the same as those described above. That is, expression of the FGF receptor led to an increase in the level of tyrosine phosphorylation that was substantially augmented when bFGF containing a signal sequence was co-expressed, but not when bFGF lacking a signal sequence was co-expressed. These results indicate that the colony Western blotting method is sensitive and can be used to rapidly and easily screen thousands of different yeast colonies. Several promoters have been tested for the expression of the FGF receptor gene in order to optimize the detection of its activation by colony Western blotting. They included the GAL1, ACT1 (actin; Gallwitz et al., Nucl. Acids Res. 9: 6339 (1981)), GPD1 (glyceraldehyde-3-phosphate dehydrogenase; Bitter and Egan, Gene 32: 263 (1984)) and TUB1 (α-tubulin; Schatz et al., Mol. Cell. Biol. 6: 3711 (1986)) promoters. Among them, the ACT1 promoter was determined to be most suitable. FGF receptor gene expression driven by GAL1 promoter proved very high, leading to high levels of tyrosine phosphorylation even in the absence of FGF, while the TUB1 promoter was extremely weak, such that FGF receptor activation by FGF could not be detected. Under the control of the GPD1 promoter, expression of the FGF receptor gene was repressed by galactose-containing media. On the other hand, the ACT1 promoter gave similar levels of FGF receptor gene expression in galactose- and in glucose-containing media, and levels of tyrosine phosphorylation were low in the absence of FGF, but significantly increased by expression of ssFGF. For these reasons, the ACT1 promoter was used for the cDNA screening experiment described below. The above results encouraged further attempts to use this method to identify novel ligands for tyrosine kinase receptors. As a first step, the method was used to identify new ligands for the FGF receptor. The purpose of this experiment is two-fold: first, to determine whether this system can be used to identify genuine FGF genes, and second, to isolate previously unidentified activators of the FGF receptor. The procedure followed is outlined diagramatically in FIG. 1. Yeast cells expressing the FGF receptor were transformed with a cDNA library expected to contain FGF gene family members. Since bFGF (Kimelman et al., Science 242: 1053 (1988)), embryonic FGF (Isaacs et al., Development 114: 711 (1992)) and int-2/FGF3 (Tannahill, et al., Development 115: 695 (1992)) are known to be expressed in Xenopus embryos, we used a cDNA library made from mRNA isolated from Xenopus eggs and embryos (egg library). A library made from XTC cells was also used (XTC library). 150,000 and 25,000 transformants were obtained from the egg and XTC libraries, respectively. In the first screening by colony Western blotting with an anti-phosphotyrosine antibody, 65 and 29 candidates were identified, and by the second screening, nine and two transformants were found to be positive (egg and XTC library, respectively). Plasmid DNA in each transformant was rescued, and re-transformed into yeast strains with and without the FGF receptor gene in order to test whether the positive signal is dependent on expression of the FGF receptor gene. Only one plasmid rescued from one of the egg-library transformants was found to be positive even in the absence of the receptor gene expression. The other genes increased tyrosine phosphorylation only when the FGF receptor gene was co-expressed. The DNA sequence of the genes present on these plasmids was determined (Table 1). Two genes encoded peptide factors with putative signal peptide sequences. One gene, designated XT1, encodes a protein with some homology to bovine angiogenin and Chinese hamster pancreatic ribonuclease A (about 30% identity; (Maes et al., FEBS Letter 241: 41 (1988); Haugg and Schein, Nucl. Acids Res. 20: 612 (1992)). The other, EG2, is homologous to cripto, which is an EGF family member, identified in both mouse and human (about 30% identity; Ciccodicola et al., EMBO J. 8: 1897 (1989); Dono et al., Development 118: 1157 (1993)). Angiogenin, like FGF, is an angiogenesis-promoting factor. Cripto is suggested to have a role in mesoderm by virtue of its embryonic localized induction. Receptors for angiogenin and cripto have not yet been identified. Taking these facts into account, XT1 and EG2 gene products could be novel ligands of the FGF receptor. The XT2 encodes a putative protease homologous to cathepsin L (58% identity with human cathepsin L; Joseph et al., J. Clin. Invest. 81: 1621 (1988); Gal and Gottesman, Biochem. J. 253: 303 (1988)). This protease might cleave the FGF receptor in yeast cells, and the cleaved fragment might have an elevated tyrosine kinase activity. EG1 was previously identified in Xenopus laevis as a heterogeneous ribonucleoprotein (Kay et al., Proc. Natl. Acad. Sci. USA 87.: 1367 (1990)). EG3 has an RNA recognition motif found in many RNA binding proteins (Kim and Baker, Mol. Cell. Biol. 13: 174 (1993)). These RNA binding proteins might increase synthesis of FGF receptor protein by increasing the efficiency of transcription or translation. Elevated expression induces autophosphorylation. EG4 encodes a novel 96 kDa protein. Recently, a gene similar to EG4 was found in C. elegans (39% identity), but its function is unknown (Wilson et al., Nature 368.: 32 (1994)). The plasmid which was positive even in the absence of the FGF receptor gene harbored a gene encoding a putative tyrosine kinase homologous to mouse cytoplasmic tyrosine kinase FER (Hao et al., Mol. Cell. Biol. 9: 1587 (1989)). XT1 and EG2, which have been identified as activators of the FGF receptor in yeast, were tested to determine whether they could also activate the FGF receptor expressed in higher eukaryotic cells. Since it is known that the activation of FGF receptor in Xenopus oocytes is linked to a rapid Ca 2+ release from internal stores (Johnson et al., Mol. Cell. Biol. 10: 4728 (1990)), Ca 2+ release assays were performed with Xenopus oocytes expressing FGF receptor. As for EG2, the EG2 protein was partially purified tagged with a flag epitope expressed in yeast. The oocytes expressing FGF receptor were labeled with 45 Ca 2+ treated with EG2, followed by Ca 2+ release assay. It was found that Ca release was stimulated by treatment of partially purified EG2 protein. As for XT1, this protein has not been expressed efficiently enough to purify the protein, so instead, XT1 mRNA was co-injected with FGF receptor mRNA into oocytes. If XT1 protein activates the FGF receptor in oocytes, it is expected that the FGF receptor would be constitutively activated by the continuous synthesis of XT1 protein, and that the basal level of Ca 2+ efflux in the co-injected oocyte would be higher than in oocytes injected FGF receptor mRNA alone. Ca 2+ efflux of labeled oocytes was measured, and it was found that co-injection of XT1 and FGF receptor mRNAs increased Ca 2+ release two-fold more than the injection of FGF receptor message alone. Co-injection of bFGF and FGF receptor mRNA increased Ca 2+ release three-fold. XT1 or bFGF mRNA alone did not increase Ca 2+ release. These results demonstrate that XT1 and EG2 can activate FGF receptor expressed in Xenopus oocytes, and that these protein synthesized in vivo can work as activators of FGF receptor. In order to demonstrate that these proteins are real ligands for FGF receptor, it will be necessary to show that these proteins bind directly to an extracellular domain of the FGF receptor. TABLE 1______________________________________Genes Which Increase Protein-Tyrosine Phosphorylation inYeast Cells Expressing FGF Receptor.FGF receptor frequencygene dependency gene product of isolation______________________________________1) secreted proteinsXT1 + homologous to angiogenin 1 and RNaseAEG2 + cripto (EGF-like growth 4 factor)XT2 + 58% identical to human 1 cathespin L2) RNA binding proteinsEG1 + heterogeneous 2 ribonucleoproteinEG3 + RNA binding protein 13) a novel proteinEG4 + novel 96 kd protein 14) FGF-receptor independentEG5 - cytoplasmic tyrosine 1 kinase TER______________________________________

Disclosed herein are compositions and methods which are useful in the identification and isolation of components involved in transmembrane receptor-mediated signaling. Such components include the receptors themselves (e.g., tyrosine kinase receptors, cytokine receptors and tyrosine phosphatase receptors), as well as ligands which bind the receptors and modulators of the downstream intracellular catalytic event which characterizes receptor-mediated signalling.

FIELD OF THE INVENTION This invention relates to a field of electronic messaging and, in particular, to cross-platform messaging. BACKGROUND OF THE INVENTION The versatility of contemporary electronic messaging services is growing and giving rise to new message formats and new devices with messaging capabilities. Emerging message formats (e.g. MMS (Multimedia Message Service), SyncML, PoC (Push-to-Talk over Cellular), etc.) are complementing the traditional messaging services (e.g., e-mail, Short Message Service, instant messaging, etc.). Accordingly, many types of communication devices start to implement messaging capabilities whereas supporting different and not always compatible message and communication formats. The problem of cross-platform messaging was recognized in the Prior Art and various systems were developed to provide a solution, for example: U.S. Pat. No. 6,782,412 (Brophy et al.) entitled “Systems and methods for providing unified multimedia communication services” discloses a platform employing a client/server architecture to provide an extensible set of real time and messaging communication services to a plurality of users. The platform allows the clients to configure and activate the services as each user wishes, thereby providing individual control over the communication services. The platform includes a server that allows a user to select how to participate in a communications event. This can include control over the end points and media over which the communications event occurs. The systems described herein additionally provide a framework for developing integrated voice and data services that can be deployed on the platform for extending the services available to the plurality of clients. U.S. Pat. No. 6,912,564 (Appelman et al.) entitled “System for instant messaging the sender and recipients of an e-mail message” discloses techniques for transferring electronic data between users of a communications system including a host system structured and arranged to receive and deliver messages of various types between users of the communications system. The host system includes an instant messaging network; a mail gateway; and a configuring network in communication with both the instant messaging network and the mail gateway. The instant messaging network enables instant messaging communication between users of the communications system and has the capability to monitor whether a certain user is capable of receiving an instant message at a particular moment. The mail gateway receives and delivers e-mail messages to users of the communications system. The configuring network is dedicated to automatically configuring instant messaging communication between an intended recipient of an e-mail message and the sender of the e-mail message. US Patent Application No. 2003/158,902 (Volach) entitled “Multimedia instant communication system and method” discloses a rich content delivery system including a rich content unit to send multi-media communications generally instantly, a presence unit to communicate with the messaging unit, and a network access layer to communicate with the rich content unit. Also described is a rich content delivery system for wireless devices including a rich content unit to send multi-media communications to wireless devices, a presence unit to communicate with the rich content unit, and a network access layer to communicate with said rich content unit. US Patent Application No. 2003/191,816 (Landress) entitled “System and method for creating and delivering customized multimedia communications” discloses a system and business methodology for providing interactive and customizable digital full-motion, animated and static multimedia content, to be used for communicating unique personalized entertainment, information, and messages and advertising to be delivered via the internet, electronic mail, or any other methods of delivering interpersonal communications and messages. The communications and messages are initiated and received by senders and recipients visiting a host site of the system through the internet. Content within the customized communication includes content personally relevant to a user which is integrally associated with sponsorship or advertising information. Creation of a customized communication begins by selection of a content item by a user, which content may be personalized by graphical editing techniques. Personalized or non-personalized content may be executed in parallel or in series with other content items in a multi-linear playback sequence compiled according to a predetermined script to produce a finished customized multimedia communication. The host site also provides other features and products desirable to users, such as screensavers, reminder services, etc. US Patent Application No. 2004/177,117 (Huang) entitled “Method of sharing multimedia” discloses a multimedia sharing method for email message recipient, involving integrating multimedia file into template to construct email message that is transmitted to recipient, and opening file when message is received. US Patent Application No. 2004/177,119 (Mason et al.) entitled “System and method for presence enabled e-mail delivery” discloses a telecommunications system including a network, a destination multimedia server, and a destination presence server coupled to the network. A plurality of multimedia clients is also coupled to the network. The multimedia clients include a presence option and are adapted to be able to select whether the option is to be activated. In operation, when a client sends an e-mail to another client, the destination multimedia server receives the e-mail and determines if the recipient supports presence. If so, the destination multimedia server sends a query to the destination presence server to check the recipient's presence. If the recipient is present, the message can be delivered. If not, the message can be held on the server until the recipient is present. US Patent Application No. 2004/267,884 (Sar-Shalom) entitled “Automatic messaging client launcher for a communication device” discloses an automatic messaging client launcher for a communication device which automatically launches the communication device's messaging client, when the device is calling a currently unavailable destination communication device. The automatic messaging client launcher consists of an availability detector and a messaging initiator. The availability detector determines if the communication device being called is available. If the destination device is unavailable, the messaging initiator launches the messaging client. US Patent Application No. 2005/15,443 (Levine et al.) entitled “Personal message delivery system” discloses a system comprising a plurality of interfaces configured to interface with plurality of subscribers communication devices using a plurality of formats. A group service module is provided configured to maintain communication among groups of the subscribers. A platform conversion module is also provided and is coupled to the plurality of interfaces and the group services modules configured to connect each of the plurality of the subscribers within a group, regardless of the communication protocols used by the subscribers. US Patent Application No. 2005/33,852 (Tenhunen) entitled “System, apparatus, and method for providing presence boosted message service reports” discloses a system, apparatus, and method for automatically providing presence information using existing messaging services. Backward messaging such as read reports and delivery reports automatically include presence information from presence server according to user preferences contained within profile database. The presence information may be disseminated through any messaging service, such as the Multimedia Messaging Service (MMS) and is also supported by Session Initiated Protocol (SIP) signalling. US Patent Application No. 2005/120,309 (Jang) entitled “Method of and apparatus for displaying messages on a mobile terminal” discloses a method and apparatus simultaneously displaying the main text and/or more attached filed of a message received in a mobile terminal. This simultaneous display allows a user to confirm the main text and attached files in the message. The main text and attached files may be shown in respective areas of the display. US Patent application No. 2005/136,953 (Jo et al.) entitled “User interface for creating multimedia message of mobile communication terminal and method thereof” discloses a user interface for creating a multimedia message of a mobile communication terminal in which menu fields for creating a multimedia message are displayed in one screen, and when inputting content for each menu field is completed, it is automatically switched to a multimedia message-creating screen in which a selecting bar is positioned at the next field. In addition, while a user is using a multimedia function, a current image can be switched to the multimedia message-creating screen according to a user's need. Thus, the number of user's key manipulations can be reduced in creating the multimedia message, thereby enhancing a user's convenience. US Patent Application No. 2005/144,236 (Ying) entitled “Identifying a device to a network” discloses a method comprising: a) receiving one of a Short Message Service, Enhanced Message Service, Multimedia Message Service, and SyncML message; b) extracting a device identifier from the message; and c) applying the device identifier to determine a device status. The device comprises information about the device's capabilities to receive, process, and display information and location information about the location of the mobile device. For example, device information may comprise information about the device's graphic display capabilities, communication bandwidth, and processor speed while the location information may be useful when delivering services to the device. Location information may be ‘literal’, e.g. a geographic address or location, or ‘logical’, e.g. “In a Meeting”, “In Transit”, and so on. The wireless network comprises subscriber information, device status, permissions and media delivery preferences. The media delivery preferences include information about the manner in which information should be communicated to the subscriber. Examples include frame rate, color schemes, visual quality, and visual layout. US Patent Application No. 2005/144,247 (Christensen et al.), entitled “Method and system for voice on demand private message chat”, discloses a system and method for establishing a private message chat between electronic devices. The method includes steps of providing an indication as to the availability of a user for receiving a private message chat; receiving an audio input message from at least one first client; and transmitting the audio input message to at least one second client over a communications network, wherein the at least one second client can receive, temporarily store and play back the audio input message. The first client may receive a reply audio input message from the at least one second client or, receive a reply text input message from the at least one second client, and subsequently may further communicate back to the second client device via one of audio or text messaging, according to that user's discretion. The transmitting of any audio input message may be accomplished via VoIP or SIP. US Patent Application No. 2005/159,135 (Kim) entitled “System and method for making a multimedia message service compatible with non-supported terminals” discloses a system and method for making a multimedia message service compatible with a non-supported multimedia message terminal. The system comprises a first system for converting a format of a multimedia message and transmitting a uniform resource locator and an access code of the converted multimedia message in response to a receiving terminal being detected as the non-supported multimedia message terminal. The system further comprises a second system for receiving the converted multimedia message, and transmitting the uniform resource locator and the access code to the non-supported multimedia terminal. The non-supported multimedia terminal receives the converted multimedia message. US Patent Application No. 2005/235,038 (Donatella et al.) entitled “Method of and apparatus for server-side management of buddy lists” discloses a method of contact lists management in a presence enabled application supported by a communication system and having a client side on a user equipment and a server side within a presence enabled network accessible by the users through said communication system, the application being of a type in which uses of the application form time-variable virtual communities of users that temporarily interact for the purposes of the application. The method includes: users' registration with the server-side of the application, to provide candidates for the virtual communities; creation, from the candidates, of a list of the members of each virtual community in a buddy list management unit in the presence enabled network; notification of the buddy list by the list management unit to client units in the user equipment of members of the community; and displaying the notified list on the user equipment of each member receiving it. US Patent Application No. 2005/243,978 (Son et al.) entitled “System and method of interworking messages between mobile communication terminals” discloses a system for inter-working messages of a mobile communications terminal employing a method of receiving by a first messaging service server a multimedia message sent by a first user client of a first messaging service, processing the multimedia message at the first messaging service server and at a second messaging service server, and providing by the second messaging service server the processed multimedia message to a second user client of a second messaging service. The message includes a parameter that indicates the originating messaging service type or the recipient messaging service type as a field or an indicator in the header portion or body portion of the message. US Patent Application No. 2006/53,227 (Ye et al.) entitled “Multi-media messaging” discloses methods, systems, and machine-readable mediums for creating multimedia messaging service (MMS) messages. In one embodiment, the method comprises receiving a message in a first format, adapting the message to a MMS message, and sending the MMS message to a user device. US Patent Application No. 2006/146,997 (Qian et al.) entitles “Communications system and method for providing customized messages based on presence and preference information” discloses communication systems which when a caller requests a communication session, e.g., voice, text or multimedia, with a callee, but due to the unavailability of the callee, the communication session is unable to be established, a message is generated and transmitted to the caller based only on the callee's presence information. Current systems have the disadvantage that they do not allow a callee to provide different presence information to different callers. This disadvantage is overcome by the application in that a communication manager which transmits a response to a caller has access to preference information which includes policies for different priority levels of callers. Thereby the response can be customized to said caller. In particular, the preference information of the called subscriber determines the type and amount of the called subscriber's presence information that is disclosed to the caller in the customized message. SUMMARY OF THE INVENTION In accordance with certain aspects of the present invention, there is provided a system for message communication via a communication media between one or more originating communication devices assigned to a sender and one or more destination communication devices assigned to a receiver, the system comprising an access block configured to receive, directly or indirectly, from at least one originating communication device a message having initial characteristics comprising message format and message layout, and to transmit the message to at least one destination communication device; a media block operatively coupled to said access block and configured to adapt, before transmitting, at least one of said initial characteristics of the message in accordance with at least one criterion selected from a group comprising: i) criterion related to message communication capabilities of the destination communication device with regard to message communication capabilities of the originating communication device; ii) criterion related to message displaying capabilities of the destination communication device with regard to message communication capabilities of the originating communication device; iii) criterion related to the communication media. The system may be further configured to support at least two destination communication devices assigned to the receiver and further comprise a database operatively coupled to the media block and configured to store historical information and/or derivatives thereof related to the message communication by the sender and/or the receiver, and a destination block operatively coupled to said media block and said database and configured to process at least part of said historical information with the help of one or more algorithms, and to estimate, in accordance with certain criterion, preferred destination communication device among the destination communication devices assigned to the receiver. The certain criterion may be related, for example, to predicted availability of certain destination device among the destination communication devices assigned to the receiver; to predicted reply time from certain destination device among the destination communication devices assigned to the receiver, one or more combinations thereof, etc. The certain algorithm may be, for example, predictive, learning, adaptive algorithms, combined, etc. In accordance with further aspects of the present invention, the processing further includes processing data related to receiver's preferences, sender's preferences; indications of actual availability of the destination communication devices assigned to the receiver, etc. In accordance with further aspects of the present invention, the system may be further configured to receive a template-based message, said template characterized by at least unique identifier and an initial layout, wherein the system further configured to recognize the unique identifier of the template, and the media block is further configured to adapt, before transmitting, the initial layout of the message in accordance with the recognized unique identifier and displaying capabilities of the destination communication device. In accordance with other aspects of the present invention, there is provided a block configured to obtain a template-based message to be communicated between one or more originating communication devices assigned to a sender and one or more destination communication devices assigned to a receiver, said template characterized by at least unique identifier and an initial layout, wherein said block is further configured to obtain information related to said unique template's identifier, and to adapt the initial layout of the message in accordance with said unique identifier and displaying capabilities of the destination communication device. In accordance with other aspects of the present invention, there is provided a block configured to obtain a message to be communicated between one or more originating communication devices assigned to a sender and one or more destination communication devices assigned to a receiver, wherein said block is further configured to obtain historical information and/or derivatives thereof related to the message communication by the sender and/or the receiver, to process at least part of said information with the help of one or more algorithms, and to estimate, in accordance with certain criterion, preferred destination communication device among the destination communication devices assigned to the receiver. In accordance with other aspects of the present invention, there is provided a method of message communication via a messaging system between one or more originating communication devices assigned to a sender and one or more destination communication devices assigned to a receiver, the method comprising: a) before delivery to the receiver, obtaining by a messaging system a message having initial characteristics comprising message format and message layout; b) adapting at least one of said initial characteristics of the message in accordance with at least one criterion selected from a group comprising: i) criterion related to message communication capabilities of the destination communication device with regard to message communication capabilities of the originating communication device; ii) criterion related to message displaying capabilities of the destination communication device with regard to message communication capabilities of the originating communication device; iii) criterion related to communication media between originating and destination device; c) facilitating delivery of the adapted message to the receiver. The method may further comprise obtaining historical information and/or derivatives thereof related to the message communication by the sender and/or the receiver, processing at least part of said historical information with the help of one or more algorithms; and estimating, in accordance with certain criterion, preferred destination communication device among the destination communication devices assigned to the receiver. In accordance with other aspects of the present invention, there is provided a method of message communication via a messaging system between one or more originating communication devices assigned to a sender and one or more destination communication devices assigned to a receiver, the method comprising: a) before delivery to receiver, obtaining by the messaging system a template-based message having initial characteristics comprising message format and message layout; said template characterized by at least unique identifier and an initial layout, b) obtaining information related to said unique template's identifier, and c) adapting the initial layout of the message in accordance with the said unique identifier and displaying capabilities of the destination communication device. Said adapting may be provided, for example, by the messaging system and/or by the originating device. The method may further comprise storing the message with initial characteristics related to message format and message layout in the messaging system; receiving from the destination device the adapted message received by the receiver and to be forwarded to a forwarding address; replacing the adapted message with the corresponding message stored in the messaging system; and facilitating delivery of the message with initial characteristics to the forwarding address. Said replacing may be provided per the receiver's request. In accordance with other aspects of the present invention, there is provided a service center for message communication between one or more originating communication devices assigned to a sender and one or more destination communication devices assigned to a receiver, the service center facilitating: a) before delivery to receiver, obtaining a message having initial characteristics comprising message format and message layout; b) adapting at least one of said initial characteristics of the message in accordance with at least one criterion selected from a group comprising: i) criterion related to message communication capabilities of the destination communication device with regard to message communication capabilities of the originating communication device; ii) criterion related to message displaying capabilities of the destination communication device with regard to message communication capabilities of the originating communication device; iii) criterion related to communication media between originating and destination device; c) facilitating delivery of the adapted message to the receiver. The service center may further facilitate obtaining historical information and/or derivatives thereof related to the message communication by the sender and/or the receiver; processing at least part of said historical information with the help of one or more algorithms; and estimating, in accordance with certain criterion, preferred destination communication device among the destination communication devices assigned to the receiver. In accordance with other aspects of the present invention, there is provided a service center for message communication via a messaging system between one or more originating communication devices assigned to a sender and one or more destination communication devices assigned to a receiver, the service center facilitating: a) before delivery to receiver, obtaining a template-based message having initial characteristics comprising message format and message layout; said template characterized by at least unique identifier and an initial layout, b) obtaining information related to said unique template's identifier; and c) adapting the initial layout of the message in accordance with the said unique identifier and displaying capabilities of the destination communication device. In accordance with other aspects of the present invention there is provided a client for a communication device configured to facilitate via a messaging system a message communication of a originating communication device assigned to a sender and one or more destination devices assigned to a receiver, said client being installed at originating device configured to facilitate composing a message having initial characteristics comprising message format and message layout and adapting at least one of said initial characteristics of the message in accordance with at least one criterion selected from a group comprising: i) criterion related to message communication capabilities of the destination communication device with regard to message communication capabilities of the originating communication device; ii) criterion related to message displaying capabilities of the destination communication device with regard to message communication capabilities of the originating communication device; iii) criterion related to communication media between originating and destination device; The client may be configured to obtain historical information and/or derivatives thereof related to the message communication by the sender and/or the receiver, to process at least part of said information with the help of one or more algorithms, and to estimate, in accordance with certain criterion, preferred destination communication device among the destination communication devices assigned to the receiver. In accordance with other aspects of the present invention, there is provided a client for a communication device configured to facilitate via a messaging system a message communication of a originating communication device assigned to a sender and a destination devices assigned to a receiver, said client being installed at originating device configured to facilitate composing a message using a template characterized by at least unique identifier and an initial layout, wherein said client is further configured to adapt the initial layout of the message in accordance with said unique identifier and displaying capabilities of the destination communication device. Among advantages of certain aspects of the present invention is capability of ubiquitous messaging between different types of communication devices via different communication protocols, adapting the sending/receiving message in accordance with capabilities of the destination communication device and the communication media and preserving user's messaging experience over a spectrum of communication devices. BRIEF DESCRIPTION OF THE DRAWINGS In order to understand the invention and to see how it may be carried out in practice, certain embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: FIG. 1 illustrates a generalized diagram of exemplary network architecture supporting message communication in accordance with certain embodiments of the present invention; FIG. 2 illustrates a generalized block diagram of a functional architecture of a messaging system in accordance with certain embodiments of the present invention; FIG. 3 illustrates a generalized block diagram of a functional architecture of a traffic management server in accordance with certain embodiments of the present invention; FIG. 4 illustrates a generalized block diagram of a functional architecture of a destination block in accordance with certain embodiments of the present invention; FIG. 5 illustrates a generalized block diagram of a functional architecture of a media block in accordance with certain embodiments of the present invention; FIG. 6 illustrates a generalized flow chart of operating the messaging system in accordance with certain embodiments of the present invention; FIG. 7 illustrates a generalized flow diagram of messaging between PC and Web clients in accordance with certain embodiments of the present invention; FIG. 8 illustrates a generalized flow diagram of messaging between mobile WAP and TV clients in accordance with certain embodiments of the present invention; FIG. 9 illustrates a generalized flow diagram of messaging between two communication devices in accordance with certain embodiments of the present invention; FIG. 10 illustrates a generalized flow diagram of template-based messaging in accordance with certain embodiments of the present invention; FIG. 11 illustrates an exemplary layout of a message displayed on cellphone screen in accordance with certain embodiments of the present invention; and FIG. 12 illustrates an exemplary layout of a message displayed on a PC screen in accordance with certain embodiments of the present invention. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present invention. In the drawings and description, identical reference numerals indicate those components that are common to different embodiments or configurations. Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing”, “computing”, “calculating”, “determining”, or the like, refer to the action and/or processes of a computer or computing system, or processor or similar electronic computing device, that manipulate and/or transform data represented as physical, such as electronic, quantities within the computing system's registers and/or memories into other data, similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices. Embodiments of the present invention may use terms such as, processor, computer, apparatus, system, sub-system, module, unit, device (in single or plural form) for performing the operations herein. This may be specially constructed for the desired purposes, or it may comprise a general purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, Disk-on-Key, smart cards (e.g. SIM, chip cards, etc.), magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), electrically programmable read-only memories (EPROMs), electrically erasable and programmable read only memories (EEPROMs), magnetic or optical cards, or any other type of media suitable for storing electronic instructions capable of being conveyed via a computer system bus. The processes/devices presented herein are not inherently related to any particular electronic component or other apparatus, unless specifically stated otherwise. Various general purpose components may be used in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the desired method. The desired structure for a variety of these systems will appear from the description below. In addition, embodiments of the present invention are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the inventions as described herein. The term “communication device” used in this patent specification should be expansively construed to include any kind of CPE (customer premises equipment) device with messaging communication capabilities, including those adapted for coupling with voice, data, video and/or multimedia terminals. The “communication devices” include fixed (e.g. DECT) and cellular phones, personal and other computers, pagers, radio telephones, dedicated data units (e.g. PDA), TV set-up boxes, digital media centers, etc. The communication device may communicate, directly or indirectly, with another communication device or with other devices (e.g. servers, public switches, service platforms, etc.) via all possible networks such as, e.g. fixed line networks, cellular networks, broadband networks, data communication networks, Internet network, cable networks, etc. using any standard or proprietary protocols supporting message communication. The term “message” used in this patent specification should be expansively construed to include any kind of communication objects capable to be exchanged between communication devices. Said communication objects are characterized by content, format and layout. The message formats include formats fitting e-mail, Short Message Service, instant messaging, EMS, MMS, SyncML, or/and other electronic messaging services, communication media and protocols thereof. The message content may include a text and/or one or more media items to be transmitted to the other party, wherein the media items may include text files, image files, moving picture files, sound files, hyperlinks, electronic signatures, etc. in any available formats. The message may be sent as one entity, as multiple entities to be re-assembled when received, one or more media items may be replaced by corresponding links, etc. The media items contained in the message, when received, may be displayed as independent objects (e.g. attachments) in accordance with a predefined layout, in a predetermined order (e.g. in a synchronized multimedia message) or otherwise. Some messages may also comprise metadata describing, for example, a structure and/or semantics of the contained media items. The metadata may carry rules and instructions (e.g. how the message or parts thereof shall be delivered, played, forwarded, stored, etc.), a counter and any other information which may aid in protecting or initiating commercial or non commercial interactions with the message. The metadata may also include tags associated with the message (e.g. for future filing and/or searching of messages and content elements thereof, etc.), “threads” providing association with other messages, etc. The metadata may include information related to digital rights pertaining to the message or parts thereof and/or any other predestinated rule. The term “message template” used in this patent specification should be expansively construed to include any kind of predefined user interface related to content and/or layout of transmitted and/or received message. Typically the template comprises a pre-existing text, and/or spaces to be filled and/or media items and/or menu elements and/or buttons and/or checkboxes to be filled/selected. The term “criterion” used in this patent specification should be expansively construed to include any compound criterion, including, for example, several criteria and/or their combination. The references cited in the background teach many principles of integrated messaging services that are applicable to the present invention. Therefore the full contents of these publications are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background. Bearing this in mind, attention is drawn to FIG. 1 illustrating, by way of non-limiting example, a generalized diagram of exemplary network architecture supporting message communication in accordance with certain embodiments of the present invention. Each of communication devices 11 (e.g. IP or regular cellular phone, DECT telephone, personal computer, PDA, TV, etc.) is connected via appropriate protocol supporting at least one message service to at least one of the networks selected from the group comprising Internet 12 or other data network, one or more networks 13 operated by a cellular operator, and one or more networks 14 operated by a landline operator. Some of these networks are connected with one or more other networks directly or via one or more networks 15 operated by a service aggregator and supporting at least one inter-network message service. The networks and/or combinations thereof comprise necessary service platforms (e.g. e-mail server, WAP server, SMSC, etc.) facilitating messaging communication known in the prior art, variants and evolution thereof. In accordance with certain embodiments of the present invention the message communication between a message originating communication device (referring hereinafter as originating device) and a message destination communication device (referred hereinafter as destination device) is provided via a system for message communication (referred hereinafter as “messaging system”) 16 . The messaging system is connected, directly or via service aggregator, with one or more networks connected to the originating device and one or more networks connected to the destination device. The originating and destination devices may have different communication and displaying capabilities and may use different communication protocols. Note that the invention is not bound by the specific network architecture described with reference to FIG. 1 . Those versed in the art will readily appreciate that the invention is, likewise, applicable to any network architecture facilitating messaging between communication devices. The messaging system(s) may constitute a part of cellular operator network(s) 13 and/or landline operator network(s) 14 and/or service aggregator network(s) 15 . The functionality of the message platform described in the present invention may be implemented in one or more stand-alone servers or, fully or partly, integrated with one or more other service and/or application platforms existing in one or more networks. The integration may be provided in a different manner and implemented in software and/or firmware and/or hardware. Referring now to FIG. 2 , there is illustrated a generalized block diagram of a functional architecture of a messaging system in accordance with certain embodiments of the present invention. As illustrated in FIG. 2 , in accordance with certain embodiments of the present invention, one or more originating communication devices are operatively coupled with one or more destination communication devices via the messaging system 16 , wherein at least one communication device is assigned to a user registered in the messaging system (subscriber). The messaging system 16 may support communication devices with different capabilities as well as communicate with 3 rd party applications 29 . The messaging system is configured to support a variety of message formats, including, but not limiting, text (including rich text), video format (e.g. MPEG family, WMV family, 3GPP, etc.), audio format (e.g. AMR family, MPEG audio layers, AAC, MIDI, etc.), image format (e.g. JPEG, GIF, BMP etc.), and others. The messaging system is configured to facilitate delivery of the message and/or notification thereof to the destination device. The messaging system is also configured to support, at least, the following modes of user's access: Using an existing communication interface and/or standard client of a communication devices (email, SMS, MMS, IM, etc.); Using a dedicated client pre-installed on the communication device; Using a dedicated client remotely delivered to the communication device using some web-like browser (Web, WAP, etc). The dedicated clients may be fully or partly standard and/or proprietary, including clients provided by 3 rd parties. In certain embodiments of the invention some functionality of the messaging system may be delegated to a client as will be further detailed with reference to FIGS. 7-9 . In certain communication devices functionality (or part thereof) of the client may be implemented also in hardware and/or firmware. Accordingly, the messaging system 16 is configured to support different clients as, for example, mobile clients, PC clients, web clients, TV clients, WAP clients, etc., wherein each of the clients is matched to the capabilities of the appropriate communication device. Some of the clients may also complement the device capabilities; for example, the TV client may be based on the middleware of the TV STB and rely on the ‘Lean back’ TV approach. The TV client may comprise highly developed messages scanning and reading options as well as chat or SMS messaging. The messaging system 16 may be also configured to recognize metadata (if any) contained in the message and to operate in accordance with system instructions related to metadata and/or instructions contains in metadata. In certain embodiments of the present invention the destination device may recognize a presence of metadata (e.g. related to digital rights) and send request to the messaging system. The messaging system may be, accordingly, configured to receive said request and to provide the destination device with instructions related to handling the message and/or parts thereof (e.g. block forward, play, decrease counter(s), etc.). The messaging system 16 comprises an access block 21 operatively coupled with several interconnected (e.g. via one or more buses 215 ) functional blocks: a destination block 22 , a media block 23 , a CRM block 24 (optionally) and a control block 25 (optionally). Said functional blocks are operatively coupled (e.g. via one or more buses 216 ) with a database 26 , a storage 27 and an administrative block 28 (optionally). The functional blocks may comprise data repository, logic and processing capabilities related to the function of the block. The access block 21 includes a users' gateway 211 and 3 rd party applications' gateway 214 supporting communication with communication devices and 3 rd party application(s) via corresponding network(s) (e.g. public switched and private fixed line networks, cellular networks, broadband networks, data communication networks, Internet, cable networks, etc.) via available communication standard, system and/or protocol (e.g. XMPP, HTTP, WAP, SMS, MMS, SMTP, etc.) and variants of evolution thereof. It should be noted that unless specifically stated otherwise, the communication with communication device includes communication via device's interface(s), standard client(s) and/or dedicated client(s) installed at the communication devices. The users' gateway 211 is connected with a traffic management server 213 via a cashing layer block 212 also constituting a part of the access block. A user can register and thus to become a subscriber as well as subscribe to and/or purchase one or more services or combinations thereof via the users' gateway. Upon registration the system assigns to the subscriber a unique identification number (e.g. number of his/her cellular phone), wherein the subscriber may have more than one assigned communication devices. The functionality of the destination block 22 and the media block 23 as well as the traffic management server 213 will be further detailed with reference to FIGS. 3-5 . In accordance with certain embodiments of the present invention, the messaging system 16 is configured to assign a personal account to the subscriber. The personal account comprises information related to the subscriber (including assigned communication devices) and settings related to the purchased/subscribed service(s). A service is characterized by a certain set of functions, limits, capabilities, quality of service and other service-related characteristics. The CRM block 24 is configured to manage and control creation and maintenance of the personal accounts. The CRM block further comprises a session manager (not shown). A term “session” used in this patent specification should be expansively construed to include any logical 3-way relationship between two communication devices and the messaging system, wherein at least one communication device is assigned to a subscriber. It should be noted that, similar to e-mail and/or SMS sessions, the sending part and receiving parts of the session may be separated in time. A session is started by a user and terminated by said user or by the messaging system. The CRM block is configured to register session(s)-related information, to match it with corresponding personal accounts and to prepare data for further billing purposes. The data and/or derivatives thereof obtained by the CRM block may be stored in the database 26 . The control block 25 comprises a privacy/spam manager 251 and digital rights manager 252 . The privacy, spam and the digital rights may be controlled and/or managed on a system level, subscriber level, group level and/or combination thereof. By way of non-limiting example, the subscriber may fully or partly deny the privacy rights to the benefits of another subscriber or subscribers' group; the spam may be controlled per subscriber/subscribers' group settings and/or per overall system settings; the digital rights for media items comprised in the messages may be managed per subscriber and/or per element (e.g. as combination of system and personal account settings, etc.), etc. The database 26 stores data related to the subscribers, services, transactions, usage and other information related to the system operation. The database is coupled to the media storage device 27 . The media storage device is configured to store media items contained in the originated messages and/or media items converted, if necessary, in accordance with certain embodiments of the present invention. Appropriate media items may be downloaded to the destination devices via relevant protocols, including but not limited to HTTP, SMTP, MMS, etc. Certain media items, e.g. items with too large volume for successful downloading, may be transmitted to the destination device with the help of streaming protocols, e.g. RTSP, RTP, etc. In certain embodiments of the invention the subscribers may have assigned storage space with configurable (e.g. per subscriber category, service, etc.) capacity. In certain embodiments of the invention the storage device is capable of on-line storing of originated message (including format, layout and content) for further message restoring if/when necessary. In certain embodiments of the present invention the system is configured to store in the storage device 27 one or more media items contained in the message, while to store at least part of metadata related to the message (e.g. tags, threads, etc.) in the database 26 . Among advantages of such splitting is reduction of duplicating media items to be stored. The administration management block 29 is configured to support service administrating (e.g. monitoring, reporting, system's tuning, manual user management, manual content management, system configuration, etc.). Those skilled in the art will readily appreciate that the invention is not bound by the configuration of FIG. 2 also as detailed in following FIGS. 3-5 ; equivalent and/or modified functionality may be consolidated or divided in another manner. In different embodiments of the invention, connection between the blocks and within the blocks may be implemented directly or remotely. The connection may be provided via Wire-line, Wireless, cable, Internet, Intranet, or other networks, using any communication standard, system and/or protocol and variants or evolution thereof. Those skilled in the art will also readily appreciate that the information related to subscribers, services, and/or usage and/or other information related to the system operation may be stored and managed within more than one database, some of these databases may be external to the system 16 and may be managed by 3 rd parties. Referring to FIG. 3 , there is illustrated a generalized block diagram of a functional architecture of the traffic management server 213 . In accordance with certain embodiments of the present invention, the traffic management server 213 is configured to manage the message delivery within the messaging system 16 . The traffic management server is configured to serve as an intersection of the system flows and to provide queues mechanism to manage (e.g. based on J2EE technologies) the flows of the internal traffic (between functional and other blocks and parts thereof) according to pre-defined functional queues, for example, a login queue 31 , a registration queue 32 , a transcoding queue 33 , a media messaging queue 34 , a presence queue 35 , etc. For example, input traffic to the CRM block 24 is managed via the login queue and the registration queue, while presence related traffic from CRM block is managed via the presence queue also supporting input traffic to the destination block. The message coming to the message block 23 is passed via the messaging queue to a message manager 231 and then via the transcoding queue to the transcoder 232 . Referring now to FIG. 4 , there is illustrated a generalized block diagram of a functional architecture of the destination block 22 . In accordance with certain embodiments of the present invention, the destination block comprises a presence manager 221 operatively coupled with a contacts manager 222 and the database 26 , wherein subscriber related information contained in the database comprises corresponding contact lists and history of communication by the originating and/or destination subscribers, including characteristics of previous deliveries (destination device, time of originating and delivery, reply time, number of attempts, etc.). The contacts manager 222 is configured to manage a list of the subscriber's contacts (including groups). This list includes one or more communication devices assigned to said contact persons, capabilities of said devices, sender's and/or receivers' preferences, if any, related to destination device, message layout and/or format, etc. This information or parts thereof may be stored in the database 26 . In certain embodiments of the invention said information or parts thereof and/or derivatives thereof may be stored in one or more external databases, and the contact manager may have capabilities to access such information. The presence manager 222 comprises an availability module 42 operatively coupled with a responsiveness module 41 . The availability module is capable of providing availability indication for one or more communication devices assigned to one or more subscribers comprised in the list managed by the contacts manager 222 . The availability indication may be provided in accordance with one or more methods known in the art, combinations, variants and evolutions thereof. In certain embodiments of the invention the destination device may be determined among devices assigned to the receiver in accordance with indication of actual availability of certain device and/or sender/receiver/system preferences. The responsiveness module comprises a processor with learning, predictive, adaptive and/or other algorithm capable of processing information related to appropriate communication history as stored in the database 26 and calculating a preferred destination device in accordance with a certain criterion. Said information may comprise data on using certain communication device (among assigned to the subscriber) under different circumstances, dependency of reply time of certain receiving device (among assigned to the receiver) under different circumstances, availability of different devices (among assigned to the receiver) under different circumstances, number of system's delivery attempts required under different circumstances or otherwise reflect communication habits and experience of the sender and/or the receiver and/or the pair thereof. In certain embodiments of the invention the criterion may be related to expected reply time (e.g. minimal reply time, average reply time, etc.) of different pairs of senders and receivers and/or pairs among assigned originating and destination devices; related to predicted availability (e.g. maximal availability, average availability, etc. of certain destination device among devices assigned to the receiver), etc. The calculations may further include sender's and/or receiver's preferences (e.g. related to the communication devices, message format and layout, etc.); settings comprised in the message (e.g. in metadata) and/or system and related to delivery instructions, digital rights management, etc.; actual availability indications provided by availability module and other parameters. The processing at least part of said information stored in the database and determining, in accordance with certain criterion, preferred destination communication device among the destination communication devices assigned to the receiver may further include analysis of communication habits/experience and/or preferences of a certain group of subscribers comprising the sender and/or receiver, and/or entire subscriber's database, and may, optionally, include data mining. In certain embodiments of the invention the results of calculations of preferred destination device and/or derivatives thereof may be saved in the database for later use. In accordance with certain embodiments of the present invention and, as detailed further with reference to FIGS. 6-10 , the messaging system is configured to obtain delivery instructions in accordance with received message and destination device, match the message format and layout to the destination device, and facilitate the delivery. In certain embodiments of the invention if, for some reason, the message is undeliverable to the preferred destination device, the messaging system is capable to define the destination device with next priority and to match the message accordingly. It should be noted that if the message is intended to be sent to several receivers, the process of determining the destination device and corresponding matching shall be provided in the similar manner for each receiver, unless other instructed. Referring to FIG. 5 , there is illustrated a generalized block diagram of a functional architecture of the media block 23 . In accordance with certain embodiments of the present invention, the media block 23 comprises a transcoder 232 operatively coupled with a message manager 231 further optionally comprising a template module 51 operatively coupled with the database 26 . The media block is configured to select the format and message layout fitting to the destination device and to convert the message accordingly before facilitating its delivery to the destination device. As will be further detailed with reference to FIGS. 6-10 , the converting includes transcoding the message format and/or adapting the message layout. The required transcoding functionalities may be implemented based on different models of transcoders available in the markets, variants and evolutions thereof (e.g. “Bulk Messaging System” (BMS) product Vimatix, briefly described in http://www.vimatix.com/bms.htm). The message manager is configured to provide layout adaptation and/ore repackaging as further detailed with reference to FIGS. 6-10 . The transcoding decision is based upon communication capabilities between originating and destination device, including supporting protocols, available bandwidth, etc. Referring to FIG. 6 , there is illustrated a generalized flow chart of operating the messaging system. In accordance with certain embodiments of the present invention, the messaging system 16 is connected with the networks 13 , 14 and/or 15 illustrated in FIG. 1 in a manner that the message communication originated by the subscriber and/or designated to the subscriber shall pass through the messaging system. In the illustrated example Subscriber A composes a message at one of communication devices assigned to said subscriber and sends the message to Subscriber B and Non-subscriber C. As the message is originated by subscriber, it will be re-addressed to the messaging system 16 . The messaging system receives the message and analyses 61 originating and destination addresses comprised in the message. If found that the destination device is assigned to a subscriber (e.g. per domain name assigned to the subscribers, IP address or other device attribute stored in the database, etc.), the system decides 62 on the destination device, and takes 63 a delivery decision accordingly. As was detailed with reference to FIG. 4 , the decision may be provided basing on actual data (e.g. actual availability, preferences, etc.), on predicted or other wise analyzed data (e.g. predicted availability, predicted preferences, receiver's availability pattern, etc.) or on combination thereof. The delivery decision comprises delivery instructions with regard to destination device(s) and/or content and/or format and/or layout of the message to be delivered. The delivery instructions or parts thereof may be received with the message (e.g. contained in the metadata), extracted and provided accordingly, and/or may be predefined in the system (e.g. in a form of a lookup table providing matching between originating device and/or destination device and format and/or layout of the message to be converted for delivery). The non-limiting examples of delivery decisions will be further illustrated with reference to FIGS. 7-10 . In accordance with the delivery decision the system provides transcoding of the message format 64 and/or adapting layout 65 and appropriate repackaging 66 if necessary (for example, if limitations by communication media and/or destination device, and/or DRM-related instructions or other reasons require deleting or replacing some of media items comprised in the message). The converted message and/or notification thereof are delivered 67 to the destination device, and the transaction is registered 68 in the system. The original and/or converted messages may be stored in the system. The described process may be provided in a similar manner for several destination devices if the message from Subscriber A shall be delivered to several destination devices assigned to the same or different receivers. Those versed in the art will readily appreciate that the illustrated operational flowchart is, likewise, applicable to message communication originated by a non-subscriber and designated to the subscriber. The illustrated operational flowchart is also applicable to a message replying and/or message forwarding from destination device. In accordance with certain embodiments of the present invention the system may be further configured to forward the original message stored in the system and not the converted message received by the forwarding device. The decision what of these two messages to select may be provided by user and/or by system in accordance with certain rules (e.g. “use an original message for forwarding mode”, “use a converted message for edit and forward mode”, etc.). Referring to FIG. 7 , there is illustrated, by way of non-limiting example, a generalized flow diagram of messaging between two subscribers wherein the originating device 71 is a desktop PC communicating with a destination PC 74 configured as a browser-based client. The subscriber A composes a message at originating device 71 and sends 711 it to the subscriber B. The assumption of the current scenario is that the subscriber A does not select the destination device and addresses the message to the subscriber B in accordance with the subscriber's unique name registered in the system (e.g. in format <cellular telephone number of subscriber B>@<domain name assigned to the messaging system/service>). The message is passed to the messaging system 16 and received via SMTP gateway 72 constituting a functional part of the user's gateway 211 in the access block 21 . The SMTP gateway parses the message and sends 712 the message to the traffic server, the traffic server passes 713 the message to the message manager constituting a functional part of the media block. In parallel the user's gateway identifies the originating device and informs the destination block (not shown). The message manager sends 714 the message media items to be stored in the storage 27 and sends 715 metadata related to said media items and/or said message to be stored in the DB 26 . The message manager sends 716 an origination/destination request to the traffic server which passes 717 the request to the destination block 22 . The destination block returns 718 the answer to the message manager. The destination may be defined in a manner detailed with reference to FIG. 4 . The traffic manager passes 719 the answer (“PC client”/“web client” in the current example) to the message manager, and the message manager obtains the delivery instructions, including message format and layout, matching to the destination device. In the current example the delivery instructions are the following: deliver the message to HTTP server without changing the message format/layout, and notify the destination device. Accordingly, the message manager passes 720 the message to the traffic server and the traffic server passes 721 the message to the HTTP gateway 73 constituting a functional part of the user's gateway. Subscriber B receives 722 a notification about the message and may download its content. Those skilled in the art will readily appreciate that in certain embodiments of the invention the SMTP, HTTP and other gateways and combinations thereof illustrated in the current and following examples may be implemented as physical part(s) of the messaging system, separate unit(s) located in the networks of cellular and/or landline operators and/or service integrator(s), or may be fully or partly integrated with one or more devices comprised in said networks. Referring to FIG. 8 , there is illustrated a generalized flow diagram of messaging between two subscribers wherein the originating device 81 comprises WAP client and the destination device 84 comprises TV client. Similar to the scenario described with reference to FIG. 7 , the subscriber A composes a message at originating device 81 and sends 811 it to the subscriber B. The assumption of the current scenario is that the subscriber A does not select the destination device and addresses the message to the subscriber B in accordance with the subscriber's unique name registered in the system. The message is passed to the messaging system 16 and received via HTTP (WAP) gateway 82 constituting a functional part of the user's gateway 211 in the access block 21 . The HTTP gateway identifies the originating device, parses the message and sends 812 it to the traffic server, the traffic server passes 813 the message to the message manager constituting a functional part of the media block. The message manager sends 814 the message media items to be stored in the storage 27 and sends 815 the related metadata or part thereof to be stored in the DB 26 . The message manager sends 816 an origination/destination request to the traffic server which passes 817 the request to the destination block 22 . The destination block returns 818 the answer to the message manager. The traffic manager passes 819 the answer (“WAP client/“TV client” in the current example) to the message manager, and the message manager obtains the delivery instructions, including message format and layout, matching the destination device/client. In the current example the delivery instructions are the following: match the message format to delivery via SMTP server and message layout to displaying via TV client and notify the destination device about the message. Accordingly, the message manager passes 820 the message to the traffic server and the traffic server passes 821 the message to the media block 23 . The media block provides a conversion of message format/layout to those matching the received delivery instructions and sends 823 the converted message to be stored in the storage 27 and informs 822 the traffic server. (If necessary for certain implementations of transcoding process, the transcoder may be further configured to obtain information about originating device from the user's gateway). Accordingly, the traffic server informs the message manager (not shown), and the message manager obtains a copy of converted message from the storage and sends it to the traffic server (not shown). The traffic server passes 824 the message to the SMTP gateway 83 sending notification 825 to the Subscriber B. The Subscriber B will receive the notification via local SMTP client embedded in the TV client and download the message. Alternatively, the media server may send to the traffic server and, accordingly, to SMTP server only information related to storage location of the converted message and retrieve said converted message and facilitate its sending per request received from the subscriber B. Referring to FIG. 9 , there is illustrated a generalized flow diagram of messaging between two subscribers wherein the originating device 91 is a PC supporting synchronized multimedia message and the destination device 94 is a PC supporting plain messages only. The subscriber A composes 911 a synchronized multimedia message at originating device 91 to be sent to subscriber B. The client in the originating device comprises some functionality delegated by the messaging system. By way of non-limiting example, the originating device is configured to be able to determine the destination device (e.g. in accordance with subscribers' preferences and/or subscriber B availability). In certain embodiments of the invention the client at the originating device may be configured to obtain availability information from the messaging system and/or other platform(s). The client may be also configured to request the messaging system for information with regard to Subscriber B preferences and/or results of preferred destination device calculations, and the messaging system may be configured to provide such information to the client. After the client obtains information with regard to the destination device, it takes 912 delivery decision and provides the appropriate transcoding 913 matching (fully or partly) the message to capabilities of destination device 94 and communication media. The converted message is uploaded 914 to the messaging system 16 and received via user's gateway 211 . The gateway parses the message and sends it to the traffic server, the traffic server passes 915 the message to the message manager. The message manager sends 916 the message media items to be stored in the storage 27 and sends 917 the related metadata to be stored in the DB 26 . The media block also sends 918 an origination/destination request to the traffic server which passes 919 the request to the destination block 22 . The destination block returns 920 the answer to the message manager. The traffic manager passes 921 the answer to the message manager and the message manager obtains the delivery instructions. In the current example the delivery instructions are the following: deliver the message without changing the message format/layout, and notify the destination device. (In certain cases if the client provides only partial matching of message, the system may complement the converting process.) Accordingly, the message manager passes 922 the message to the traffic server and the traffic server passes 721 the message to the users' gateway. The gateway sends 922 the message notification to Subscriber B. In accordance with further aspects of the present invention, the messaging system may facilitate composing messages using pre-defined templates. In accordance with certain embodiments of the present invention the messaging system supports different types of templates, including, but not limiting, the illustrated in Table 1. Each type of template and/or each template is provided with unique identifier capable to be recognized by the messaging system and/or client and stored in the message metadata. TABLE 1 Template's type Content Structure Direction General Pre-defined text with capability of composing 1-way multimedia message comprising one or more media items (e.g., images, audio clips, video clips). Optionally part of media items and/or placeholders thereof may be pre-defined. Greeting - Pre-defined graphics with capability of 1-way like inserting text and/or media items. Interactive Pre-defined text with capability to insert one or 2-way message more media items to be selected by receiver for (initial sending in reply. Part of media items and/or message and placeholders thereof and/or buttons and/or reply) checkboxes may be pre-defined. Email Pre-defined text with capability of editing and 1-way attaching media items Text Pre-defined text with capability of editing 1-way The templates may be stored in the communication device and/or the messaging system, and may be personalized in accordance with subscriber's preferences and/or the communication device. Some of the templates may include one or more predefined rules and/or wizards guiding the subscriber through composing template-based messages, prompting input and dynamically updating the output. For example, an interactive template (e.g. conversation template, voting template, decision template, etc.) may facilitate the message-composing subscriber to select two or more media items to be suggested to the receiving subscriber as options for selection, ranking, voting or other similar action and add a text and/or media file for instruction. The message receiving subscriber does not need to compose a message for reply, he/she may just provide the expected action (e.g. select certain media item) and, optionally, add text and/or media item. For example, the message-originating subscriber may place images of different products and add audio file with a question what to buy. The receiving subscriber upon receiving such message may select appropriate “Yes”/“No” button/checkbox (or, for example, delete non-relevant images) and reply. The invention, in some of its aspects, is aimed to provide a novel solution facilitating ubiquitous templates supporting different types of originating and destination devices and seamlessly matching the template-based messages to capabilities of the originating and/or destination devices and subscriber's preferences. Bearing this in mind, attention is drawn to FIG. 10 , illustrating a flowchart of template-based message communication in the messaging system described with reference to FIGS. 1-9 . In accordance with certain embodiments of the present invention the system and/or client are configured to provide 111 the subscriber with a template. The template may be personalized in accordance with subscriber's preferences. The template may comprise (and/or or enable to use) emotions, visual messages and other non contextual data. The messaging system is configured to recognize 112 template-based messages and the template unique identifier comprised in the message metadata, and to analyze 113 the content structure of the template. The messaging system obtains 114 a delivery decision in a manner similar to detailed with reference to FIGS. 6-9 wherein delivery instructions include instructions related to template adaptation to displaying capabilities of destination device. In accordance with delivery instructions, the system provides format transcoding 115 and template adapting 116 and facilitates the message delivery 117 . The template adapting includes converting the template type and/or template layout. The layout of certain template depends on capabilities of destination device as, by way of non-limiting example, is illustrated in Table 2. In accordance with certain embodiments of the present invention a template serves as an “envelope” for the message during the communication. The system may match only envelope (template) or the envelope (template) and the message itself. Accordingly, for template-based messaging the delivery instructions with regard to layout of the message are based on predefined layout of message matching to template unique identifier and capabilities of destination device. The layout may be further predefined in accordance with information to be obtained with regard to certain filled field, format of selected media items, etc. Among advantages of certain aspects of the present invention is reduction in need of content analysis and ability to provide layout-related delivery instructions based on pre-defined rules and parameters (e.g. in a form of a look-up table). In certain embodiments of the invention the type of template in combination with subscriber (or system) preferences may have impact on decision on destination device and/or format transcoding. For example, the “interactive reply” messages may be required to be always delivered to the device originated the “interactive initial” message and/or via protocol matching to said message type. TABLE 2 Templates' type Layout for PC Layout for Web Layout for cell-phone General Basic frame Basic frame graphics Basic frame graphics graphics Sender's avatar Sender's name Sender's avatar Text Text Text List of clickable For images: list of List of clickable media thumbnails clickable media, media thumbnails Media display area, reduced for device Media display area reduced for web For audio/video: list Controls for playing Controls for playing of clickable icons all media all media into reduced media continuously continuously Reply controls Save media controls Save media controls Forward controls Reply controls Reply controls Forward controls Forward controls Greeting Basic frame Basic frame graphics Basic frame graphics like graphics Sender's avatar Sender's name Sender's avatar Predefined animated Text Predefined animated graphics with text on Predefined reduced graphics with text Reply controls animated image Reply controls Forward controls Reply controls Forward controls Forward controls Interactive Basic frame Basic frame graphics Basic frame graphics initial graphics Sender's avatar Sender's name Sender's avatar Text Text Text List of images, List of images, List of images reduced for web reduced for device Controls to select Controls to select Controls to select one one or more of the one or more of the of the images images images Reply controls Reply controls Reply controls Interactive Basic frame Basic frame graphics Basic frame graphics reply graphics Sender's avatar Sender's name Sender's avatar Text Text Text List of images, Selected image, List of images reduced for web reduced for device Indication for Indication for Reply controls selected images selected images Reply controls Reply controls Email Basic frame Basic frame graphics Basic frame graphics graphics Sender's details Sender's details Sender's details Text, truncated Text, truncated Text, truncated Links to attachments Reply controls Links to attachments Reply controls Forward controls Reply controls Forward controls Forward controls Text Basic frame Basic frame graphics Basic frame graphics graphics Sender's avatar Sender's name Sender's avatar Text Text Text Reply controls Reply controls Reply controls Forward controls Forward controls Forward controls If the template-based message is designated to a non-subscriber, the templates module 51 extracts the initial template (per template ID) from the storage 27 , restores information of initial message layout and provides it for further matching. Referring to FIGS. 11 and 12 , there are illustrated exemplary layouts of messages displayed on cell phone and PC screens. In accordance with further aspects of the present invention, the client to be downloaded to communication device shall support one or more of the following features: composing a template-based message (e.g. using drag-and-drop controls); visual editing of media items (e.g., cropping images and songs) as part of composing; managing contacts and groups, including contact icons; enabling sending a message by drag-and-drop on contact icons; managing contact privileges and blocking; managing message assigned labels; synchronizing messages between client and messaging system; setting user preferences; automatically providing indication of user's availability; enabling a user to provide manual indications of availability; enabling message sharing between devices assigned for one subscriber and/or within a group of subscribers. It should be noted that the invention is not bound by the specific one-to-one scenarios described with reference to FIGS. 6-10 . Those versed in the art will readily appreciate that the invention is, likewise, applicable to one-to-many and many-to-many message communication, including communication in a group. It is to be understood that the invention is not limited in its application to the details set forth in the description contained herein or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Hence, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the concept upon which this disclosure is based may readily be utilized as a basis for designing other structures, methods, and systems for carrying out the several purposes of the present invention. It will also be understood that the system according to the invention may be a suitably programmed computer. Likewise, the invention contemplates a computer program being readable by a computer for executing the method of the invention. The invention further contemplates a machine-readable memory tangibly embodying a program of instructions executable by the machine for executing the method of the invention. Those skilled in the art will readily appreciate that various modifications and changes can be applied to the embodiments of the invention as hereinbefore described without departing from its scope, defined in and by the appended claims.

A method of cross-platform messaging including receiving, by a messaging system, at least one initial message having a message format, an initial message layout and data indicative of at least one user associated with the at least one initial message, and before delivery to a destination communication device associated with the at least one user, converting, by the messaging system, an initial message into an adapted message, and facilitating, by the messaging system, delivery of the adapted message to the destination communication device. The adapted message is characterized by, at least, an adapted message layout, and the adapted message layout differs from the initial message layout in a characteristic associated with respective message layout such as number of media objects, a graphical image of a media object, a size of a placeholder related to a media object, and a location of a media object within a respective message layout.