A packed mass transfer tower for establishing intimate gas/liquid contact and efficient mass transfer that is less susceptible to gas or liquid channeling, gas surging and uneven distribution of gas or liquid across the cross-sectional area of the tower. The packed tower includes a packing arrangement including a lower bed of mobile packing elements, and an adjacent upper bed of fixed packing elements. The packed bed of fixed packing elements acts as a gas distributor, as well as causing good gas/liquid contact, to provide an even flow of gas across essentially the entire cross-sectional area of the packed bed of mobile packing elements.

It is well known that packed towers or columns are often useful for efficient gas/liquid contact to provide interactions, reactions and other mass transfer operations between gas and liquid. However, in some such operations the fluid passing through the packed bed contains suspended solid particles that tend to accumulate on the packing, eventually resulting in a reduction in gas/liquid volumetric flow rates and, in extreme cases, plugging of the tower.
Such plugging problems occur, for example, when a packed tower is used with liquids or gases that contain particulate material, or when particulates are formed within the tower as a result of a chemical interaction, reaction or the like, that precipitates solids as a result of mass transfer between the liquid and the gas. For example, in flue gas scrubbing that utilizes a liquid stream that includes an aqueous solution or suspension of limestone, or the like, to remove sulfur dioxide contained in a gas stream, a calcium sulfate precipitate is formed in the tower, and the resulting aqueous slurry causes plugging problems. Another example is a gas/liquid interphase oxidation process for removal of hydrogen sulfide from a gas stream that uses an oxidizing solution to effect oxidation of hydrogen sulfide to form elemental sulfur particles. Such particles may cause plugging of packed towers, requiring periodic shutdown of the process for a difficult and time consuming cleaning of the tower.
Some prior processes have used packed towers for contact of hydrogen sulfide (H.sub.2 S)-containing gases with an aqueous iron-chelate solution or a so-called "Stretford"-type alkaline vanadium ion-containing wash solution that converts H.sub.2 S to elemental sulfur (S.degree.). The elemental sulfur formed is entrained in the liquid mixture, and subsequently removed from the liquid, e.g., by settling or filtration. In this type of H.sub.2 S removal process, some of the sulfur settles on the packing material, thereby lowering gas and liquid flow rates and, ultimately, the sulfur plugs the tower. Mobile packing beds have been used in packed towers for sulfur removal from H.sub.2 S-containing gas streams but suffer from uneven gas distribution and channeling problems, particularly in larger cross-sectional area towers, resulting in decreased efficiency.
It is well known that two of the most important characteristics necessary for effective and efficient gas/liquid mass transfer in packed towers are 1) the tower must contain adequate passages for both the liquid and the gas streams without excessive liquid holdup or pressure drop; and 2) the tower must provide good contact between liquid and gas. The requirement of good contact between liquid and gas is the most difficult to meet, especially in large towers. Ideally, the liquid, once distributed over the top of the packing, flows in thin films over all the packing surface completely down the tower. Actually, the films tend to grow thicker in some places and thinner in others, so that the liquid collects into small rivulets and flows along localized paths through the packing. Especially at low liquid rates, and in the larger towers, some of the packing surface may be dry or covered with a stagnant film of liquid. This effect is known as "channeling" and is the main reason for poor performance in large packed towers. Similarly, a countercurrently flowing gas stream, especially in larger towers, sometimes tends to follow localized paths instead of being distributed across the entire cross-section of the tower, with a consequent increase in velocity through these localized paths, and this effect is known as "surging".
The use of mobile packing beds tends to decrease or eliminate packing material fouling, adds to the "channeling" and "surging" problems inherent in packed towers of relatively large cross-sectional area due to the tendency of the relatively light mobile packing material to collect along the sides and other localized areas of the tower, further decreasing the desired cross-sectional uniformity of gas and liquid flow. This reduces the overall efficiency in relatively large mobile bed gas/liquid contact devices. This problem has been recognized for many years but, to date, no adequate solution to the channeling and surging problems has been achieved. Others have provided vertical partitions in the columns between grids, to provide a plurality of partitioned packing beds between adjacent grids, thereby decreasing the cross-sectional area of each separate packing bed. This partitioning has aided the gas and liquid flow uniformity, but not completely satisfactorily, and has created other problems, such as the attendant difficulty in loading and unloading packing material and making sure that loading is done uniformly within each separate compartment.
The present invention solves this gas/liquid flow problem within mobile bed packed towers, by including at least one bed of mobile packing elements supported on a fluid-pervious grid disposed vertically below at least one bed of fixed packing elements supported on another fluid-pervious grid.

Multi-bed mass transfer column with mobile packing


The present invention provides cell lines capable of indefinite growth which are produced by transforming leukocytes isolated from peripheral blood of fish with a oncogene, a method of establishing the cell line, a method of recovering immunologically active substances from the culture of the cell lines. It has been difficult to maintain continuous cultures of fish leukocytes. The present invention provides cell lines capable of indefinite growth and a method of producing immunologically active substances, e.g., immunologically acitive substances, using these cell lines.

Fish disease and injuries pose serious problems in the cultivation of various species of fish. Fish disease can spread to aquaculture, which is the husbandry of aquatic animals and plants, and cause to kill all the fish in aquaculture, which results in devastating damage to aquaculture. Contamination of infectious agents in aquaculture make it impossible to culture fish in the same facilities again. These problems have been a major problem of stable supply of fish. In addition, to prevent and treat fish disease, a large amount of antibiotics has been used for culturing fish, and the use of a large amount of antibiotics may cause problems in human health. To prevent or solve these problems, the present inventors have contemplated a method for enhancing a self defense system of fish by externally administering immunologically active substances to fish. These substances are originally secreted out from the leukocytes of fish so that it is necessary to isolate such cells from fish to establish a cell line. The cell line should be capable of indefinite growth and of producing immunologically active substances.
There have been various methods of obtaining cell lines capable of indefinite growth. These methods use hybridomas that tumor cells fused with lympocytes obtained from human (Kohler, G. et al., 1975, Nature 256: 495), transformants that are produced by transforming cells with tumor causing herpesvirus or EBV (Epstein, M. A., & Achong, B. G., 1979, The Epstein-Barr Virus Springer-Verglag, Berlin), T lympocytes transformed with HTLV-1 (Sugamura, K., et al., 1984, J. Immunol. Methods, 34: 221) and pre-B cells transformed with Ab-MLV (Reth, M. G., et al., 1985, 317:353). Cells derived from B lymphocytes are useful for producing hybridomas while T lymphocytes and leukocytes are not suitable for producing hybridomas. In fact, there has been no report on hybridomas produced from these cells so far. Serious drawbacks of hybridomas produced by cell fusion are their instability and undesirable changes in their properties during culture and subculture. Transformation is useful for producing transformants from leukocytes using various viruses. The transformants, however, also have properties of viruses so that the properties of the transformants are totally different from those of the original cells.

Cell lines produced by transforming leukocytes of fish with oncogenes and physiologically active substances produced by the cell lines


Techniques and modes of operation for using network interfaces in a single or multi-CPU environment are disclosed. The techniques provide a virtual “vertical perimeter” framework suitable for processing data through multiple network interfaces assigned to a single CPU. In this framework, techniques for installing and servicing a plurality of network interfaces with a single CPU utilizing virtual vertical perimeters and sub-queues is disclosed. A computer system including at least one CPU and more network interfaces than CPU's is disclosed. At least two of the interfaces are assigned to an associated CPU. The computer system includes an operating system with plurality of sub-queues and an associated sub-queue controller. The sub-queues are associated with at least two network interfaces assigned to the CPU. The sub-queue controller is configured for coordinating the generation and operation of the sub-queues thereby to facilitating message traffic through the at least two network interfaces.

Computer systems typically utilize a layered approach for implementing functionalities relating to communications frameworks where a protocol layer is a program module for processing different portions of data traveling from a network to an application or when the application decides to send data out to remote peer over the network. The layered approach requires examination of data by each protocol layer to determine if any work needs to be performed by that layer before sending the data to the next protocol layer.
In some conventional implementations "horizontal perimeters" are provided to provide per module or per protocol stack layer processing. This leads to the same packets being processed on more than one Central Processing Unit (CPU) in a multi-CPU environment. In addition, conventional techniques typically provide only a single application in multi-CPU environments. This means that applications and packets can be processed by different CPU's at various times. In addition, data related to the applications (application data) is shared between the CPU's.
In any case, conventionally, in a multi-CPU environment (e.g., multi-processor server) data (message packets) can be stored and processed by different CPU's at various layers in the process. Typically, for better efficiency, the application data is stored in caches associated with the CPU that is currently processing the message packets. But if the processing CPU changes at any time, a cache miss can occur. This means that, among other things, message packets may need be transferred from the cache of one CPU to the cache of another CPU. This means that any one of the CPU's can be interrupted when data (e.g., a packet) is received into the shared operating system via a network interface. The CPU that is interrupted needs to access data. However, data may be in cached in another CPU (i.e., not the interrupted CPU). This results in the need for cache miss handling. Moreover, if the cache was modified in between, this operation becomes very expensive. This problem is exacerbated in environments where there is a significant data load on the system (i.e., the system is very busy).
One approach to combating this problem was to introduce vertical perimeter architectures. Such vertical perimeters vertically integrate message processing in a manner that specifically binds a designated network interface card to a specific CPU for all message traffic through the designated network interface card. This is accomplished using an S-queue (serialization queue) that enables the vertical processing of a message by the same CPU at all steps required to process a message of the designated network interface card. Moreover, such architectures are capable of controlling the interrupt mode used to pass messages between the network interface card and the kernel of the operating system. Thus, when the S-queue becomes too full or when the rate at which data is been received by the NIC becomes higher than some threshold the interrupt mode is of the network interface is halted until the is more room in the associated S-queue. The nature of some vertical perimeter architectures is explained in greater detail in, for example, U.S. patent application Ser. No. 10/767,021, entitled "VERTICLE PERIMETER FRAMEWORK FOR PROVIDING APPLICATION SERVICES", filed on Jan. 28, 2004, which has been incorporated by reference.
Such conventional vertical perimeter frameworks are suitable for many purposes, but when the number of network interfaces exceeds the number of CPU's certain system inefficiencies slow reduce the capacity of the overall systems. For example, if the data from two NIC's are being input into the same S-queue the system cannot readily distinguish which NIC provided the data. Any efforts to distinguish which NIC provided a given piece of data would require a further investment of kernel processing time thereby further slowing down the operation of the system. Thus, if one NIC (e.g., NIC A) is pouring in a large amount of data and another NIC (e.g., NIC B) is pouring in a relatively small amount of data the slower NIC (NIC B) suffers. This is due to the serial nature of the S-queue. Data comes out in the order it was placed in the S-queue. This results in significant kernel time being devoted to the processing of messages for NIC A and less time for NIC B. Thus, a connection using NIC B can have a very long delay before a connection can be completed due to large number of messages for NIC A that must be processed first. Moreover, NIC B is doubly penalized because every time a new piece of data comes in for NIC A the kernel is interrupted further slowing processing. Also, if an extraordinarily large amount of data arrives from NIC A, the S-queue can be completely filled require NIC B data to remain on the NIC until such time as there is room in the S-queue. Also, because two (or more) NIC are now feed data to the S-queue the system loses its ability to regulate the data flow from the NIC. Therefore, improvements can be made.

Computer architecture and process for implementing a virtual vertical perimeter framework for an overloaded CPU having multiple network interfaces


Techniques and circuitry provide fast, accurate, proper, and reliable transfer of configuration data from an on-chip nonvolatile memory to the programmable logic core of a programmable logic integrated circuit. A first technique includes not allowing the programmable logic to be configured until the data held in the on-chip nonvolatile memory can be read correctly and reliably. A second technique includes verifying the configuration data is transferred from the nonvolatile memory to the programmable logic core correctly and without error during the transfer process. These two techniques may be combined or used individually during the configuration of an integrated circuit.

The present invention relates to the field of integrated circuits and in particular, to an integrated circuit having a programmable logic array portion with volatile configuration memory and a nonvolatile memory array portion.
Integrated circuits are important building blocks of the modern age. Technology continues to evolve and integrated circuits continue to provide improved functionality. As integrated circuits improve, so do the electronics systems that are built using integrated circuits. There are many types of integrated circuits such as memories, microprocessors, application specific integrated circuits (ASICs), and programmable logic. Programmable logic integrated circuits such as PALS, PLDs, FPGAs, LCAs, and others are becoming more complex and continually evolving to provide more user-programmable features on a single integrated circuit.
Modern programmable logic integrated circuits incorporate programmable logic including logic gates, product terms, or look-up tables. Some programmable logic integrated circuits also include embedded user-programmable memory or RAM. However, this RAM is volatile, which means once power is removed from the integrated circuit, the contents of the RAM are lost.
Despite the success of programmable logic, there is a continuing desire to provide greater functionality in a programmable logic integrated circuit, but at the same time, provide greater performance. There is a need to provide programmable logic (configurable using volatile memory such as SRAM) with on-chip nonvolatile memory. This nonvolatile memory may be used as storage for configuration data, used to program the SRAMs upon power up of the integrated circuit.
When the integrated circuit is powered up, the voltages to the internal circuits may not be at their full operating levels. It is important that during power up of the integrated circuit, the configuration data is transferred to the programmable logic as quickly, accurately, and reliably as possible.
Therefore, there is a need to provide techniques and circuitry for ensuring the fast, accurate, proper, and reliable transfer of configuration data from an on-chip nonvolatile memory to the programmable logic core of a programmable logic integrated circuit.

Techniques for configuring programmable logic using on-chip nonvolatile memory


A decoration part includes a base member having a front-side surface and an outer peripheral end portion, a skin covering the front-side surface of the base member, and a holding member mounted to the front-side surface of the base member and arranged on a rear-surface side of the skin. The skin has a stitch line formed with a thread, and a part of the stitch line is arranged in the outer peripheral end portion. The holding member holds the thread with which the skin and the holding member are sewed and has a linear shape extending along the stitch line. The holding member has a mount portion mounted to a holding member mount portion of the base member and a stitch portion that is sewed with the thread. The holding member has the stitch portion closer to an outer peripheral end of the base member than the mount portion.

A decoration part includes a skin, a base member and a holding member (a sewing plate), for example. A stitch line is formed on a surface of the skin and the holding member is made of a synthetic resin and arranged between the skin and the base member. The skin and the holding member are sewed together with a stitching thread (a sewing thread) forming the stitch line and the holding member is fixed to the base member (a core member). Accordingly, the skin and the holding member are sewed together with the stitching thread more firmly and surely compared to a configuration in which only the skin is sewed with the stitching thread.


The present invention is concerned with a process for the catalytic hydrogenation of organic compounds on a catalyst of amorphous metal alloys and in a solvent, with the hydrogenation being carried out under near-critical or supercritical conditions of the solvent. The amorphous metal alloys can be produced by the shock cooling of alloy melts having eutectic solidification points. By hydrogenation at hydrogen partial pressures between 5 and 400 bar there is obtained outstanding space-time yields with high long-term stability of the catalytic activity.

1. Field
The present invention is concerned with a process for the catalytic hydrogenation of organic compounds on a catalyst of amorphous metal alloys under near-critical or supercritical conditions of the solvent.
2. Description
Amorphous metal alloys are also known in the art as metallic glasses. They can be produced, for example, by the shock cooling of the molten alloy on a cooled, rotating copper wheel. Depending on the nature of the surface of the copper wheel and on the precise process conditions there are obtained thin metal ribbons (in the case of a smooth copper surface) or flake-like particles, so-called flakes, (in the case of a rough copper surface). The thickness of the metal ribbons or of the flakes lies in the range between 5 and 50 .mu.m, preferably between 10 and 30 .mu.m, especially about 20 .mu.m. If the ribbons or flakes were to be made thicker, heat cannot dissipate at a rapid enough rate. Increasing the thickness increases the formation of a crystalline alloy structure.
Metallic glasses obtained in the above process are non-porous. Their surface is therefore formed exclusively by their external geometric surface. This surface area is only about 0.5 m.sup.2 /g in the case of the preferred metal ribbons or flakes of 20 .mu.m thickness. In contrast, activated nickel powder catalysts have specific metal surface areas of more than 100 m.sup.2 /g and finely dispersed palladium catalysts carried on active charcoal have specific metal surface areas of more than 40 m.sup.2 /g.
Although the catalytic properties of metallic glasses have been investigated intensively, because of their small metal surface area, they have never before been used as catalysts for industrial processes. An overview on the state of the art for catalysis on metallic glasses is found in the article "Glassy Metals in Catalysis" by A. Baiker in "Topics in Applied Physics" Vol. 72., pages 121-162, Ed. H. Beck and H.-J. Guntherodt, published by Springer 1994.
Metallic glasses can catalyze a large number of hydrogenation reactions, for example the hydrogenation of nitrogen, ethene or butadiene (see European Patent No. 0 173 088 B1) at temperature in the range of 90.degree. C. to 450.degree. C. and gas pressures of below 10 bar.
Catalytic activity depends on the respective alloy composition of the metallic glass. For example, Pd.sub.81 Si.sub.19 glasses have been found to be especially suitable for the selective hydrogenation of alkynes to alkenes [A. Molnar et al.; J. Catal. 101: 67-72 (1986)]. However, these hydrogenations were carried out at room temperature and at atmospheric hydrogen pressure.
In spite of the fundamental suitability of metallic glasses for catalytic hydrogenations, the small metal surface, low thermal stability and the formation of stable oxide layers on the surface of the metallic glasses during their production were seen to be serious obstacles for their use in industrial hydrogenation processes [D. Gasser and A. Baiker, Applied Catalysis, 48: 279-294 (1989)]. Moreover, it was suspected that the action of hydrogen would cause the metallic glasses to become friable, which would finally lead to their pulverization.
Thus, an object of the present invention is to provide an industrial process for the catalytic hydrogenation of organic compounds on metallic glasses, which overcomes the obstacles known from the state of the art for the use of metallic glasses in industrial hydrogenation processes, permits hydrogenations with high space-time yields and good long-term stability of the catalytic activity, and solves the problems associated with the reactant spending too much time on the catalyst.

Catalytic hydrogenation using amorphous metal alloy and a solvent under near-critical or super-critical conditions


A method to facilitate detoxification and treat substance addiction by administration of ketamine and a benzodiazepine. A preferred dosage range of ketamine is about 0.01 mg/kg of body weight to about 1 mg/kg. Pharmaceutical compositions comprising this dosage range of ketamine in a gum or candy are also provided. In a specific example, a dedicated smoker was able to reduce her craving from three packs of cigarettes a day.

Ketamine ((2-(2-chlorophenyl)-2-(methylamino)-cyclohexanone) is a general anesthetic used by anesthesiologists, veterinarians, and researchers. Nasal administration of ketamine, in one instance with midazolam, to achieve sedation for an ophthalmic procedure, and prior to elective surgery in healthy children has been reported (Louon et al., 1993, Br. J. Ophthalmol. 77: 529-530; Weksler et al., 1993, Can. J. Anaesthesia 40: 119-121). Usually, ketamine is administered intramuscularly (i.m.) or intravenously (i.v.) for induction of anesthesia.
Ketamine has also been known to have analgesic properties (Domino et al., 1965, Clin. Pharmacol. Ther. 6: 279); analgesia can be achieved with subanesthetic doses of ketamine (Bovill, 1971, Br. J. Anaesth. 43: 496; Sadove et al., 1971, Anesth. Analg. 50: 452-457). The drug is administered by various routes, including i.v., i.m., caudal, intrathecal, and subcutaneous (s.c.). Subcutaneous administration of ketamine has been used to treat pain following surgery and associated with terminal cancer (see, e.g., Oshima et al., 1990, Can. J. Anaesth. 37: 385-386). Ketamine hydrochloride administered via a subcutaneous cannula was reported to successfully treat phantom limb pain (Stannard and Porter, 1993, Pain 54: 227-230).
Detoxification and treatment of addictive diseases generally involves a complex and poorly understood interplay between the psychological and physiological components. Seven withdrawal symptoms can accompany detoxification from substances such as alcohol, narcotics, depressants, and stimulants. While marked by significantly less severe physical symptoms, the withdrawal symptoms associated with detoxification from smoking may include nervousness, shakiness, difficulty concentrating, impatience, and ill tempered behavior. Furthermore, detoxification is only an acute component of the treatment of addictive disease. Long term treatment, to be successful, must provide strong physical and psychological reinforcements to avoid the addition.
Thus, an area of grave concern for medicine is detoxification and withdrawal from dependence on addictive substances, including narcotics, cocaine, alcohol, and tobacco (both nicotine and smoking itself). In particular, medicine provides no satisfactory relief for withdrawal from smoking or from nicotine addiction. While the general perception holds that addiction to tobacco is the least profound of these addictions, from a public health perspective, it may be the most important. Furthermore, the current supports for treatment of smoking or nicotine addiction, such as the nicotine transdermal patch or nicotine gum, treat the addiction with an addictive substance delivered by tobacco use. Such treatment is logically impossible: it reinforces the very behavior to be eliminated. No adequate substitute, capable of reinforcing the absence of tobacco ingestion, is presently available.
Thus, there is still a critical need in the art for an agent that can assist in detoxification and withdrawal from addiction to substances, particularly smoking.
The citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

Administration of ketamine for detoxification and to treat substance addiction, and compositions therefor


An image forming apparatus of the invention permits a toner cartridge equipped with a non-volatile memory storing various information items to be mounted in a mounting portion of an apparatus main body through a toner-cartridge mounting panel capable of being opened and closed without suspending an image forming operation. In a case where an opened/closed status of the toner-cartridge mounting panel is detected, the apparatus retrieves cartridge-specific information from the non-volatile memory of the toner cartridge. The other data than the cartridge-specific information is read out only from a non-volatile memory of a toner cartridge, the cartridge-specific information of which differs from cartridge-specific information stored in a memory of the apparatus main body.

1. Field of the Invention
The present invention relates to: an image forming apparatus such as copiers and printers; a method of acquiring toner-cartridge information from a toner cartridge removably mounted in such an image forming apparatus and equipped with a non-volatile memory; and a toner cartridge. Particularly, features of the invention reside in that the image forming apparatus permits the replacement of the toner cartridge without suspending an image forming operation of the image forming apparatus and in that confirmation of the mounted state of the toner cartridge, retrieval of information stored in the non-volatile memory of the mounted toner cartridge and such are accomplished easily.
2. Description of Related Art
The image forming apparatuses conventionally used, such as copiers and printers, include one in which a variety of cartridges containing various consumables, such as the toner cartridge containing therein a toner, are removably mounted in an apparatus main body.
In a case where the toner cartridge containing therein the toner is replaced, such an image forming apparatus requires a proper toner cartridge corresponding to an apparatus model or the like to be mounted therein in order to ensure proper image formation.
More recently, the following image forming apparatus has been proposed which employs a toner cartridge equipped with the non-volatile memory storing therein various information items including: cartridge-specific information such as an ID code; a color of the contained toner; toner quantity; use conditions; and the like. When this toner cartridge is mounted in the image forming apparatus, the image forming apparatus retrieves the information stored in the non-volatile memory so as to determine whether the mounted toner cartridge is proper or not (see Japanese Unexamined Patent Publications No.2002-169429 and No.2004-3309945).
The above image forming apparatus encounters the following problem when the toner cartridge is replaced. It is a common practice to temporarily suspend even an ongoing image forming operation before a front panel, a toner-cartridge mounting panel or the like is opened to replace the toner cartridge. The replacement of the toner cartridge involves the temporary suspension of the image forming operation, thus disabling a continuous image forming operation. Hence, image forming efficiency is lowered.
In order to form a full color image, the above image forming apparatuses is also adapted to permit a plurality of toner cartridges containing toners of different colors to be mounted in the apparatus main body.
In the image forming apparatus wherein the plural toner cartridges containing the toners of different colors are mounted, the apparatus main body is generally connected with the respective toner cartridges for discrete communication with the respective non-volatile memories thereof. Through such communications, the various information items stored in the respective non-volatile memories of the toner cartridges may be retrieved, or overwritten with new information.
However, problems of complicated wirings and control are encountered by the constitution wherein the apparatus main body is in discrete connection with the respective non-volatile memories of the toner cartridges for performing the discrete communication with the respective non-volatile memories of the toner cartridges.
An alternative constitution is also contemplated wherein the apparatus main body and the respective non-volatile memories of the toner cartridges are interconnected by means of one wire bus so that all the toner cartridges are sequentially accessed for data retrieval.
In this case, however, substantial time is taken to retrieve the data by sequentially accessing all the toner cartridges. More recently, the non-volatile memory of the toner cartridge, in particular, has been increased in capacity and hence, an enormous quantity of time is taken to retrieve the information stored in all the non-volatile memories of the toner cartridges.

Image forming apparatus, method of acquiring toner-cartridge information and toner cartridge

Konica Minolta Business Technologies, Inc.


A network device determines the presence of the pre-specified string in a message based on a sequence matching rule. A sequence represents non-contiguous portions of the message. A combination of content addressable memory, programmable processing units, and the programmable control unit may determine the presence of the pre-specified string in the message by comparing the non-contiguous portions of the message. Such an approach may reduce the computational resources required for searching the pre-specified string in the message.

A computer network generally refers to a group of interconnected wired and/or wireless devices such as, for example, laptops, mobile phones, servers, fax machines, and printers. The computer network may support transfer of data, in the form of messages, between the network devices. A network device may determine the presence of one or more pre-specified strings in a message. Such a determination may be preformed, for example, by a security application, a billing application, or other similar applications. A network device may determine the presence of a pre-specified string such as a virus signature in a message based on, for example, a matching rule.
The network devices that determine the presence of pre-specified strings in a message may use, for example, a longest common sequence matching rule. The matching rules such as the longest common sequence matching rule may compare a start byte in the pre-specified string with each byte in the message until a match is found. After a match for the first byte is found the subsequent bytes of the pre-specified string and the message are byte-wise compared to determine a longest common sequence match. However, byte-by-byte comparison techniques may be computationally intensive.

Determining the presence of a pre-specified string in a message


The present invention is related to quick release holders that grip the beading of a conveyor belt. Due to a holder's unique structure, without the use of tools, the holder can manually be opened to release the beading and the conveyor belt. Conversely, without the use of tools, the holder can also be manually closed to secure the beading.

1. Field of the Invention
Among other things, the present invention is related to a holder mounted to a conveyor frame. The holder includes a mounting bracket and a pivoting bracket. A plurality of holders are mounted to the conveyor frame to grip tautly the beading of the conveyor belt as the belt circulates about the conveyor. Due to a holder's unique structure, without the use of tools, the holder can manually be opened to release the beading and the conveyor belt, or manually closed to grip the beading.
2. Description of the Previous Art
1) U.S. Pat. No. 5,955,466-Almes, et. al., owned by Applicant, discloses a belt conveyor with a belt reinforcing member. FIG. 1 discloses a beading and a beading holder. However, the '466 patent is silent regarding a spring loaded pivoting beading holder.
2) U.S. Pat. No. 5,360,102-Schoning, owned by Applicant, enables a belt conveyor with rotary guides for marginal portions of the belt. FIG. 3 discloses a beading and a beading holder. However, like Almes, the '102 patent is silent regarding a spring loaded pivoting beading holder.
3) U.S. Pat. No. 1,254,941-Snow discloses a corner for conveyors. The Snow Patent does not teach a beading or a beading holder.
4) U.S. Pat. No. 3,217,861-Daniluk, et al. describes an endless belt conveyor. The Daniluk Patent teaches the use of grommets 52 and rollers 54. The '861 patent does not disclose a beading or a beading holder.
5) U.S. Pat. No. 3,901,379-Bruhm teaches an angular guidance for conveyor belt systems. Columns 2 and 3 teach, "As shown in FIG. 4 the shoulder 10 is provided with oblique side faces 17 against which the cylindrical running surfaces of rollers 12 and 14 come to rest, which rollers are uniformly spaced over the entire length of the edge rail 4. The rollers 12 on the external sides of the belt are equipped with axes 13 while the rollers 14 mounted on the inner side are provided with axes 15 . . . The roller pairs 12 and 14 are housed in portion 7a of the curve guidance frame 7, which portion encompasses shoulder 10." The '379 patent does not teach or disclose a spring loaded pivoting beading holder.
6) U.S. Pat. No. 4,024,949-Kleysteuber, et al. discloses a traverse bendable endless belt conveyor. FIG. 3 and Column 4 reveal, "Brackets 24, 25 support the rollers 15, 16 that hold the respective beads 12, 13. The drive motors 17 along the upper run are positioned within the bracket and framework 20, as shown. Suitable support casters 26, 27, or other support feet, such as skids, are provided along the bottom cross member 23 for support of the structure on the floor F of a mining passage, for example." The '949 patent does not teach or disclose a spring loaded pivoting beading holder.
7) U.S. Pat. No. 4,846,338-Widmer enables a curved conveyor element. Column 2 teaches, "Rollers 19, during their rotation on pin 18, are supported on their jacket surfaces by a guide face 23 of guide rails 13 and 14. In this embodiment of the invention, dog members 22 are fastened to conveyor belt 1 by rivets 24 and 25 and a tongue 26, conveyor belt 1 being pulled by dog members 22. The dog members are disposed below the upper reach 1a of conveyor belt 1 so that goods being transported may project beyond the outer curvature of the conveyor belt when traveling through the curves." The '338 patent does not teach or disclose a spring loaded pivoting beading holder.
8) U.S. Pat. No. 5,038,925-Chrysler enables a conveyor for transporting articles along a curved path. FIG. 3 and Column 4 teach, "The outer frame 116 includes an upper pair of guide rails 136, 138 arranged adjacent the upper portion of the endless belt 132 and a lower pair of guide rails 140, 142 arranged adjacent the lower portion of the endless belt. The first pair of guide rails 136, 138 are horizontally and vertically offset from each other and extend continuously along the length of the outer edge of the upper portion of the endless belt 132. Similarly, the lower pair of guide rails 140, 142 are horizontally and vertically offset from each other and extend continuously along the length of the outer edge of the lower portion of the endless belt 132. As a result of the spaced apart relationship between guide rails 136 and 138 and guide rails 140 and 142, there is formed an upper path 144 and a lower path 146, respectively, for receiving a plurality of guide assemblies 148." The '925 patent does not teach or disclose a spring loaded pivoting beading holder.
9) U.S. Pat. No. 5,332,082-Sommerfield describes a conveyor turn drive. Column 3 reads, "A guide rail 31 wall forming part of the outer rail structure is slotted to receive the upper course 30a (refer to FIG. 4) of the belt, which rides on a bed structure indicated at 32 forming part of on the frame of the machine. A series of guide rollers 33 is secured to the belt along a line parallel to the outer edge for engagement with the guide rail 31 above and below the slot engaged by the belt. The lower (return) course of the belt is engaged in a similar slot in the portion of the guide rail 31 opposite the path of the lower course." The '082 patent does not teach or disclose a spring loaded pivoting beading holder.
10) U.S. Pat. No. 5,332,083-Axmann enables a curved belt conveyor. Column 4 reads:                Any unavoidable longitudinal and transverse forces that occur as belt 11 circulates are accommodated by the smooth-out rollers 40 that rest against the side of elevation 32 facing the center of curvature. Any irregularities in the advance of the belt are compensated for by the resilient force of the rollers mounted on the pivoting levers 42. It has been demonstrated that wear on elevation 32 and belt 11 deriving from the pressure of smooth-out rollers 40 can be maintained very slight.        FIG. 3 illustrates only how the elevation 32 on upper strand 14 is engaged. The mechanisms and actions in the vicinity of the lower strand are identical.        In this embodiment pairs comprising one smooth-out roller 40 and one hold-down roller 41 rest against the elevation 32 at the edge of belt 11, the hold-down rollers against the top of the elevation and the smooth-out rollers against its inner side. Since the same situation occurs at the lower strand, the two strands will always rest precisely against belt-backing rollers 18.        Each smooth-out roller 40 rotates freely at an acute angle and each hold-down roller 41 perpendicular to belt 11 on the same lever 42. The lever pivots at pivot 43 on a countervailing bearing 44 that can be raised or lowered in a bracket 45 secured to outside wall 16. The bracket is an upside-down L with its upright secured to outside wall 16 and the its arm projecting toward the center 13 of curvature at a level above the belt. The countervailing bearing 44 for the lever 42 that hold-down roller 41 and smooth-out roller 40 rotate on is a threaded bolt that extends through the arm and is adjusted in height by nuts 46 and 46′ that screw tight against the arm.        The hold-down roller 41 in each pair of rollers is maintained in position by raising or lowering countervailing bearing 44 and hence the pivot 43 that the lever 42 accommodating rollers 40 and 41 pivots from. The oblique smooth-out roller 40, however, is as aforesaid forced against the side of elevation 32 facing the center of curvature by tension spring 47. One end of tension spring 47 is attached to roller-accommodating lever 42 and the other end to another countervailing bearing in the form of a bolt 48 secured to outside wall 16. Bolt 48 is threaded and screws into a matching threaded bore of the bracket 45 of outside wall 16. The bolt is maintained in adjustment to the bracket and wall by a nut 49.
Axmann's spring 47 is attached to his roller-accommodating lever 42. Among other things, unlike Applicants' invention, the '083 patent does not disclose a spring-loaded bolt that connects a pivoting bracket to a mounting bracket and forces the pivoting bracket to contact the mounting bracket.
11) U.S. Pat. No. 5,394,977-Cline enables an apparatus for use in replacing conveyor belts. Column 3 discloses:                In FIG. 1, there is illustrated a power turn 2 comprising an endless conveyor belt 4 having an arcuate outer edge portion 6 and an arcuate inner edge portion 8. The endless conveyor belt 4 is mounted around conical rolls 10, only one shown, mounted on a frame 12. A portion of the frame 12 includes an arcuate support 14, in FIG. 2. A plurality of bearing standoffs 16 are mounted at circumferentially spaced apart locations on the arcuate support 14 using headed threaded bolts 18 threaded into threaded openings (not shown) in the arcuate support 14. Each bearing standoff 16 has a central body portion 20, an upper portion 22 which projects upwardly from the central body portion 20 and is inclined relative thereto and a lower portion 24 which projects downwardly from the central body portion 20 and is inclined relative thereto. Each of the upper and lower portions has an opening 26 and a slot 28 formed therein, FIG. 3, for purposes described below.        An angle bracket 40, FIG. 4, is mounted on each of the upper and lower portions 22 and 24. The angle bracket 40 has a first portion 42 and a second portion 44 having a 90 degree relationship. A roller bearing 46 having a cylindrical surface 48 is mounted on each second portion 44 using a headed threaded bolt 50 threaded into a threaded opening 52 in the second portion 44. The first portion 42 has a threaded opening 54 and a slot 56 having an off-set arcuate opening 58 formed therein.        The first portion 42 is pivotally mounted on each of the upper and lower portions 22 and 24 using a headed threaded bolt 60 passing through the opening 26 and threaded into the threaded opening 54. A roller bearing 62 having a cylindrical surface 64 is mounted on the first portion 42 using a headed threaded bolt 66 passing through the slot 28 and the arcuate opening 58, and the roller bearing 62 is secured where desired by the threaded nut 68.
Cline teaches the use of bolts 60 to mount bracket 40, roller bearing 62, roller bearing 46 to standoff 16. Cline's mount bracket 40 is not pivotable. The '977 patent does not teach or disclose a spring loaded pivoting beading holder.
12) U.S. Pat. No. 5,682,975-Wells defines a curved belt conveyor. Columns 3 and 4 read:                On the occurrence of a need to change the belt of the conveyor, the nut 48 may be slackened, and the slide plate 32 lifted relative to the wall 14, the lug 46 moved upwardly on the bolt 44, causing the trackway parts 22a, 24a to separate from the trackway parts 22b, 24b. Shown generally in dotted lines in FIG. 2. Such separation allows the roller assemblies 18 to pass between the said trackway parts, allowing the conveyor belt to be drawn on both upper and lower reaches from the frame in the direction C inwardly of the corner unit. Necessary repair or maintenance which may typically be replacement of one of the roller assemblies, or replacement of the bearing strip 26, of effective repair to the belt itself, may then be carried out relatively easily, prior to the remounting of the conveyor belt on the frusto-conical rollers 10, and return of the trackway parts of their FIG. 2 positions. Finally, the end most roller 10 may be moved outwardly to tension the belt, prior to recommencement of use of the conveyor system.
The '975 patent does not teach or disclose a spring loaded pivoting beading holder.
13) U.S. Pat. No. 6,564,931 B1-Edelmann enables a belt conveyor. Columns 5 and 6 read, "The guide rollers 12 are fastened on angled retaining arms 13 of a retaining structure 14 such that they act on the toothed-belt component 9 and/or on the bead 11 by way of inclined running surfaces. 15 designates bores of the retaining structure 14 which serve for external fastening on the belt table. The counterpressure device 10 is positioned and secured by a connection to the retaining arm 13, this connection being indicated by the dashed drill line designated 16." The '931 patent does not teach or disclose a spring loaded pivoting beading holder.

Quick release holder for a beading of a conveyor belt and method of using quick release holder


The invention provides a high-strength hybrid component comprising a relatively soft first part -made of a composite material consisting of an organic matrix reinforced with fibres, a relatively hard second part made of metal, metal alloy or ceramic, and a transition layer made of a composite material consisting of a matrix of a material which is weldable to the hard part and fibres which are extensions of the fibres of the soft part. The transition layer matrix and the hard part may be formed by deposition of molten material on to the fibre preform of the soft part, using flame, electric arc or plasma, and the resin matrix of the soft part is impregnated into the preform and polymerized afterwards.. Alternatively, the hard part may be machined to shape and welded to the transition layer before completing the soft part.

1. Field of the invention
The invention relates to hybrid components which comprise at least one first part made of composite material consisting of a fibre-reinforced organic resin matrix, and at least one second part added to it and made of metal, metal alloy or ceramic material. Examples of such components may include, inter alia, a link with an added head, a turbomachine blade with an added leading edge, and a casing with added bosses.
The invention also relates to a method of manufacturing such components.
2. Summary of the prior art
Components made of composite material comprising a mass of reinforcement fibres, for example of carbon or silicon carbide (SiC), embedded in a matrix of polymerization-hardened organic resin are often used in industry, particularly in the aeronautics industry, on account of their high strength/mass ratio compared with similar components made entirely of metal. In the components with the best performance, the reinforcing fibres are made into preforms before their impregnation with resin. A preform is an assembly of sheets of fabric which are woven from the fibres intended to form the reinforcement, the sheets of fabric being cut out and assembled together to form at least partly the shape of the component to be made, and thus take up at least part of its volume. The preform may also be made as a monofabric, i.e. a fabric constituted by several sheets of fibres woven together, such a fabric exhibiting a particularly high resistance to decohesion between the sheets of fibres. However, such components made of composite material pose difficulties resulting from the general properties of the organic resin constituting the matrix, namely low hardness and low resistance to temperature, such difficulties not occurring with metal or ceramic components.
A first problem is, therefore, to make components of composite material having a fibre-reinforced organic matrix, in which the parts which are stressed and able to assume a great variety of shapes will be made of metal, metal alloy or ceramic capable of taking the stress and formed to the required shape.
The difficulty lies in the method of bonding between the organic composite part and the metal part, when the area of contact between these two parts is subjected to concentrations of stresses:
of mechanical origin when the metal part protrudes from the composite part and is subjected to stresses tending to pull it out; PA1 of mechanical origin, again, as a consequence of different moduli of elasticity or Young's moduli; PA1 of thermal origin, as a consequence of very different thermal expansion coefficients. PA1 a) making a fibre preform to the shape of the soft part of the component together with the transition layer; PA1 b) forming the transition layer by plasma projection of a molten material onto a portion of the preform, said material being weldable with the material of the hard part; PA1 c) forming the hard part of the component, particularly in rough form, on the transition layer; PA1 d) inserting the assembly constituted by the preform, the transition layer and the hard part into a mould; and PA1 e) injecting resin into the mould so as to impregnate the preform to form the soft part, polymerizing said resin, and removing the resulting assembly from the mould. PA1 f) building up the material of the hard part using flame, electric arc or plasma projection; or PA1 g) machining the second part, and welding it to the transition layer. PA1 elimination of the risk of deformation of the component as a result of a wall of the mould pushing against the hard part, which is still not precisely shaped at this stage of the process; and, PA1 saving on resin, as the elastomer prevents the very liquid resin from moulding around the hard part. PA1 a) the metal or ceramic part is not a simple coating but a prominent part of variable shape, and is welded to the matrix of the transition layer which is interpenetrated by the fibres of the first part; PA1 b) this metal or ceramic part is obtained by building it up with material, or by welding a formed part, prior to the resin impregnation of the fibre preform. PA1 a very strong bond of the welded type between the two portions; and, PA1 perfect soundness of the material of the portion made of organic composite material.
These phenomena are worsened when the metal part is rigid, and thus thick, or when at least one dimension of the area of contact is substantial, which makes it necessary to reinforce the bond by additional mechanical means such as screwing, rivetting, seaming, etc.
A second problem is therefore to effect a very strong bond between the parts of the component made of an organic matrix composite and the parts made of metal, metal alloy or ceramic.
The low resistance of organic resin to abrasion and to impact from foreign bodies poses problems particularly in the case of aircraft propellers. These same problems also arise with the blades of turbine engines for aircraft, especially the fan blades which are situated well to the front of the engines. Indeed, as such blades rotate at speeds of up to 3000 rpm, and may have a height (from root to tip) of up to 1200 mm with a thickness below 30 mm, they are particularly exposed to abrasion by sand entering the engine, or to impact from heavy foreign bodies such as birds.
To overcome these problems, the leading edge of the blade may be covered by a metal coating, but there is then the bonding problem referred to previously. German Patent 4411670 describes a blade in which the bonding of its leading edge to the remainder of the blade is reinforced by screws and seams.
This solution requires additional manufacturing operations, and the strength it achieves remains limited since an excessive number of seams will weaken the blade by the multiplication of the holes made through it. The leading edge is therefore thin and flexible, which does not allow it to withstand properly impacts from heavy objects such as birds.
The low resistance of organic matrix composite materials to localized compressions, for example of punching type, originates from the fact that reinforcement fibres have no effect under this type of stress, whereas they are very effective with respect to tensile stresses. This problem arises in the provision of fixing points for rivets or bolts in components made of composite material, for example, air intake casings, covers or cones for aircraft engines. The problem is only partly solved by using rivets or bolts with wide heads and nuts, as such width remains limited, and substantial concentrations of stresses subsist at the fixing points, requiring a reduced tightening force and an increase of the number of fixing points.
U.S. Pat. No. 4,006,999 discloses a turbomachine blade made of a composite fibre-resin material and including a metal leading edge widely covering the convex and concave flanks of the blade. The composite part of the blade is itself composed of two parts holding grids in the vicinity of the mean plane of the blade. These grids protrude forward and are embedded in the metal constituting the leading edge, so as to strengthen the bond between the leading edge and the remainder of the composite blade. However, the effectiveness of such a solution remains limited, as this bond is effected essentially at the centre of the leading edge, the bonding of the flanks of the leading edge with the remainder of the composite blade being achieved only by adherence. Furthermore, the method of making and assembling the leading edge with the remainder of the blade is not clearly apparent.
The low temperature resistance of organic resins restricts the utilization of components made of composite materials incorporating such resins. A process is known for the thermal protection of metal parts in which plasma projection is used to produce a heat insulating ceramic shield on the surface of the parts. However, the application of this process to parts made of composite material having an organic matrix gives rise to two difficulties:
Firstly, it is not applicable to parts of substantial dimensions because of the great difference between ambient temperature and the temperature at which molten ceramic sets, and of the vitreous type of fracture of the ceramic.
Indeed, on cooling, the ceramic, because it has a greater thermal expansion coefficient, will contract more rapidly with a high risk of cracking, a high compression of the composite material part, and a substantial concentration of stresses tending to bring about detachment of the ceramic layer.
Secondly, the heat released by the plasma projection of molten ceramic onto the part made of composite material will cause considerable degradation of the resin, reducing the strength of the part. The released heat will also bring about the destruction by pyrolysis of the resin in the vicinity of the surface of the part, which reduces the strength of the bond between the ceramic layer and the composite part of the component.
A process is known for the protection of components made of a composite material consisting of reinforcement fibres and organic resin, involving plasma projection of a layer of molten metal or metal alloy onto the component. This process suffers from the drawbacks described above, and although the danger of cracking may be reduced by using a malleable material, the process is restricted to the formation of thin protective coatings on components which are not greatly stressed.

Hybrid component with high strength/mass ratio and method of manufacturing said component

Societe Nationale d'Etude et de Construction de Moteurs D'Aviation "Snecma"


Systems and methods for the detection of motions of a pointed object upon a writing surface such as a touchpad is disclosed. The motions will be detected and converted in a multiplexing analog-to-digital converter to digital codes representing the location of the pointed object and the pressure of the pointed object upon the touchpad. The location and the pressure will be translated into a pen detect signal indicating the presence of the pointed object upon the touchpad. The pen detect signal will be translated into a stroke signal to interpret a single tap, a double tap, and a tap and drag of the pointed object on the touchpad. The digital codes will be averaged to minimize noise and formed into an absolute coordinates digital code. The absolute coordinate digital code, the pressure digital code, and the pen detect signal will be converted to a touchpad-computer interface protocol. Further, multiple sets absolute coordinates will translated into a relative motion code. The absolute coordinates will be interpreted by an autocursor controller to determine if the pointed object has transited between a workzone and an edgezone of the touchpad to generate an autocursor code. The relative motion code, the stroke signal, and the autocursor code will converted to an industry standard computer input mouse protocol. An autopower control circuit and a battery gauge circuit will determine and control the battery condition.

1. Field Of The Invention
The present invention relates to computer system input devices such as a digitizers referred to as touchpads and more particularly to the systems and methods necessary to acquire signals from such input devices and to convert the acquired signals to digital codes that are transmitted to the computer system.
2. Description of Related Art
Touchpads are small digitizer based devices that are pen input devices to allow a person to write or draw upon the surface of the touchpad and have the signals and codes from a controller to be interpreted by a computer system. The touch pad digitizers may be of three types, capacitive, resistive and electromagnetic.
Referring to FIG. 1, the surface 12 of the touchpad becomes a "writing surface" for capturing the position of an pointed object 10 such as a finger, pen or stylus upon the touchpad. The touchpad signals are analog signals that will be captured by a touchpad interface circuit 28 and translated to digital codes that will be transferred to a computer system 32 on an interface 30. The interface 30 may be an industry standard serial interface, an industry standard parallel interface, or a custom interface requiring special adapter circuitry within the computer system 32 to accept the digital codes from the touchpad interface 28.
An example of a resistive touchpad is shown in FIG. 1. The resistive touchpad is made up of multiple layers of resistive films and protective layers. The protective hard coating 12 is the surface onto which the pointed object 10 is pressed upon during the writing and drawing. A first layer of resistive film 14 is attached to the protective hard coating 12 on the surface opposite the writing surface. This first layer of resistive film forms the Y-plane of the touchpad. Attached to the surface of the Y-plane resistive film 14 opposite the surface attached to the hard protective coating 12 is a second resistive film 16. This second resistive film 16 forms the X-plane of the touchpad. Finally attached to the side of the X-plane resistive film 16 is a supporting back layer 18. This back layer provides protection and mechanical support for the for the X-plane and Y-plane resistive films 14 and 16.
The touchpad interface 28 is connected through the touchpad interface lines 20, 22, 24, and 26. Each line will provide a stimulus such as a current or voltage to the periphery of the X-plane resistive film 16 and the Y-plane resistive film 14. As shown in FIG. 2, as the pointed object 10 is pressed 40 on the touchpad surface 12, the Y-plane resistive film 12 will deform and touch the X-plane resistive film 14. The X-plane resistive film can not deform because it is supported by the supporting back layer 18. This causes the Y-plane resistive film 14 and the X-plane resistive film 16 to come into contact with each other. This will cause a response in the form a change in voltage or current depending upon whether the stimulus from the touchpad interface 28 of FIG. 1 is a constant voltage or a constant current. If the stimulus from the touchpad interface 28 of FIG. 1 is a constant voltage the currents through the touchpad interface lines 20, 22, 24, and 26 will be modified according to the position of the pointed object 10 on the touchpad surface 12. However, if the stimulus from the touchpad interface 28 of FIG. 1 is a constant current the voltages between the touchpad interface lines 20, 22, 24, and 26 will be modified according the position of the pointed object 10 on the touchpad surface 12.
Referring back to FIG. 1, the touchpad interface 28 will have a set of analog to digital converters that will sense the change in the analog responses from the touchpad interface lines 20, 22, 24, and 26 and convert them to digital codes indicating the absolute position of the pointed object 10 upon the touchpad surface 12. The digital codes may be transmitted directly to the computer system across the interface 30 and translated to absolute coordinates within the computer system or the touchpad interface 28 may determine the absolute coordinates and transmit them directly to the computer system 32. For the computer system 32 to use the absolute coordinates generated by the touchpad interface 28 to control the movement of the cursor 36 upon the display screen 34, these absolute coordinates must be modified to codes that define the relative motion of the cursor 36. The relative motion will be the speed and direction of the cursor 36 as it is moved across the display screen 34. The modification from absolute coordinates to relative motion information must be done with in an internal mouse emulation program resident within the computer system 32.
A mouse is a point and click device that can be attached to a computer system to control the movement of a cursor on a display screen of the computer system. As described in "A Hardware and Software Resolution For A Pointing Device" AN569, in the Embedded Control Handbook, Microchip Technology Inc., 1994, "a standard motion translator for mice is the use of two slotted wheels, one each for horizontal and vertical direction. Also, there are two optical receivers per slotted wheel. As the slotted wheel turns, infrared beams of light are alternately transmitted and blocked, thereby sending a series of ones and zeros to optical transistor receivers. The two optical receivers are offset from each other such that the resulting signals are 90.degree. degrees out of phase. The phase difference results in two distinctly separate signals. The (mouse) controller interprets what direction the mouse is moving along either axis by the order is receives those two signals." The mouse controller counts the number of pulses per unit time and since the spacing of the slots and bars is uniform and equal in number, the relative velocity along each axis is calculated.
The direction and relative velocity are coded to set of mouse motion digital codes. These codes may be of several formats. Two representative mouse motion digital codes are shown in Table 1. The first is for the Microsoft Mouse from Microsoft Corp. and the second is for the PS/2 Mouse from International Business Machines (IBM).
TABLE 1 ______________________________________ Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 ______________________________________ Microsoft Mouse Format 1 not used 1 L R V7 V6 H7 H6 2 not used 0 H4 H3 H2 HI HO 3 not used 0 V4 V3 V2 VI VO IBM PS/2 MOUSE FORMAT 1 Y OVR X OVR Y SIGN X SIGN RES RES SB PB FLOW FLOW 2 DELTA X MOTION 3 DELTA Y MOTION ______________________________________
For the Microsoft Mouse, Bit 5 of Byte 1 indicates if the left button of the mouse is depressed. Bit 4 of Byte 1 indicates if the right button of the mouse is depressed. Bits 3 and 2 of Byte 1 and bits 0 through 5 of the Byte 3 indicate the relative motion of the mouse in the vertical direction. Bits 1 and 0 of the Byte 1 and bits 0 through 5 of Byte 2 indicate the relative motion of the mouse in the horizontal direction. These codes form signed binary numbers. If the vertical signed binary number V0:V7 is positive the mouse is moving downward and if the vertical signed binary number V0:V7 is negative the mouse is moving upward. If the signed binary number H0:H7 is positive the mouse is moving toward the right and if the signed binary number H0:H7 is negative, the mouse if moving toward the left. The magnitudes of the horizontal H0:H7 and the vertical V0:V7 signed binary numbers indicate the relative velocity of the mouse movement.
For the IBM PS/2 mouse, Bit 0 of the first Byte indicates the Primary (in the Microsoft Mouse Left Mouse Button) Mouse button has been pressed. Bit 1 of the first Byte indicates the Secondary (in the Microsoft Mouse Right Mouse Button) Mouse button has been pressed. Bits 2 and 3 of the first Byte are reserved and not used. Bit 4 of the first Byte is an X direction sign bit, where if it is a 1, the X data (or horizontal) is negative and Bit 5 of the first Byte is a Y direction sign bit, where if it is a 1 the Y data (vertical) is negative. Bit 6 and Bit 7 of the first Byte are overflow bits for the X and Y data respectively, indicating that the mouse is traveling faster than the circuitry can reliably calculate its velocity. Byte 2 indicates the total movement (Delta X)of the mouse in the X direction since the last report of movement. Byte 3 indicates the total movement (Delta Y)of the mouse in the Y direction since the last report of movement.
If the touchpad is to emulate the mouse movements, when the cursor 36 is to moved across the display screen 34 for a relatively long distance, the pointed object 10 must be repeated lifted and placed back on the touchpad surface 12 repeatedly giving a "rowing" motion to get the cursor 36 to move the long distance. In traditional mouse operations, if the cursor 36 is to drag an object being displayed upon the display screen 34 a button on the mouse is depressed while the mouse is moved. The button can be held depressed while the mouse is moved in the rowing motion to drag the object across the display screen 34. This is difficult to accomplish on the touchpad. If the pointed object 10 is lifted from the touchpad, the touchpad interface 28 will not be able to communicate the "rowing" motion to indicate that the cursor 36 is to travel a long distance. Also, the touchpad interface 28 will not be able to communicate that there is an intention for the cursor 36 to drag the object on the display screen 34. Additional buttons must be added to the touchpad or special areas within the surface of the touchpad surface 12 in order for the touchpad interface 28 to communicate the desire for the cursor 36 to be moved long distances across the display screen 34 or that the cursor 36 is to drag objects upon the display screen 34.
Touchpads such as described in FIG. I have applications to mobile, portable, or lap top computing systems which are self contained and are powered by a battery power source. The amount of energy remaining in the a battery and the amount of energy consumed by the components of the computer system such as the touchpad and the touchpad interface are factors that must be continuously monitored and regulated to maximize the operation time of these mobile computer systems.
A class of mobile or portable computer systems are known as personal digital assistants. The personal digital assistant uses a touchpad as the primary human input interface. Handwriting must be interpreted to text and drawings to create commands and data to operate the personal digital assistant.
To interpret the hand writing accurately information regarding the pressure of the pen or stylus upon the touchpad and whether the pen is in contact with the touchpad to determine an end of a stroke for the formation of a character. Handwriting interpreting algorithms as currently applied, have only a series of recent history of the absolute coordinates of the location of the pointed object 10 of FIG. 1 upon the touchpad. From these coordinates the handwriting must be interpreted to commands and characters. If the pressure and stroke information is available handwriting interpretation could be more accurate.
U.S. Pat. No. 4,812,828 (Nishi, et al.) discloses a video display processor that is connected to a mouse or a light pen. The processor will place the pulse signals form a mouse to X and Y counters to create codes that represent the amount of movement of the mouse when in the mouse mode. The processor will clock the X and Y counters to create codes that represent the absolute coordinates of a light pen on a display screen, when in the light pen mode. And the processor will clock the X and Y counters until a collision signal, which is generated by associated circuitry, when the animation patterns of the video image are overlapped.
U.S. Pat. No. 5,260,697 (Barrett, et al.) discloses a digitizing tablet overlaying a display screen. The system allows for the simulation of computer input devices such as a mouse and keyboard by a pen upon the digitizing touch tablet. The simulations are accomplished through programs within an interface processor.
U.S. Pat. No. 5,327,161 (Logan, et al.) describes a method to emulate mouse input devices using a program resident within a computer system. A touchpad input device has a controller that generates a digital code that contains the absolute position of a pen or finger on the mouse pad. This requires a special interface that is unique to the touchpad circuitry. Additionally, this patent describes a method for the continuation of cursor movement when a pointed object is touching the touchpad and has been moved on the touchpad to a special border area. The pointed object must be stopped within the border for the continuous motion to be engaged. The direction of the scrolling may be made as a modification of the original direction and velocity of the pen prior to the transiting and stopping within the border area of the touchpad. This modification will be made as a change in the velocity of the movement of the cursor along an axis parallel to the edge of the touchpad adjacent to the border area where the pointed object is resting.
U.S. Pat. No. 5,376,946 (Mikan) describes a circuit using an EPROM to convert signals from a touch screen adhered to a computer display screen to digital codes of the industry standard computer input mouse protocols.
U.S. Pat. No. 5,420,943 (Mak) describes a universal input device for a computer which can be used as a point and click device to read bar codes, a bar code scanner, a mouse, a handwriting input device, or a text scanner. The device has a pen with a CCD array and pad with bar codes and a grids for accomplishing the mouse and bar code scanning functions.
U.S. Pat. No. 5,543,590 (Gillespie, et al.) describes a capacitive sensor system that can detect the location of a finger or stylus on a sensor matrix. The location is determined and translated as electrical signals for use in other circuitry such as a computer system to control a cursor upon a display screen. Further this patent discusses an "edge motion" detection feature that will allow a finger or stylus within a "outer zone" of the sensor matrix to move the cursor to move across a display screen for long distances and avoid the "rowing" motion.
U.S. Pat. No. 5,543,591 (Gillespie, et al.) discloses methods for recognizing tapping, pushing, hopping and zigzagging gestures upon a conductive sensor pad that can be interpreted into cursor control motions such as clicking, double clicking, and click and drag use with computer mouse devices. Further this patent also describes the "edge motion" feature as described in U.S. Pat. No. 5,543,590 (Gillespie, et al.).
U.S. Pat. No. 5,488,204 (Mead) shows a proximity sensor system that has a capacitive touchpad. The capacitance of the touchpad changes with the proximity of an object to the touchpad. As the capacitance changes a voltage changes which is converted to electrical signals representing the X and Y coordinates of the object on the touchpad. A conductive paint brush stylus is used to produce paint-like strokes on a display screen associated with the touchpad. The system also incorporates features that allow the stylus to emulate the actions of a computer mouse including an "edge motion" where a cursor can be moved over long distances without rowing or stroking the stylus.
U.S. Pat. No. 5,266,750 (Yatsuzuka) discloses a tablet input device and circuitry for providing stimulating voltages to the tablet input device and for sensing the response voltages from the tablet input device when the tablet input device is being pressed. The circuitry provides an OFF state wherein power to the tablet is minimized during a waiting period.
U.S. Pat. No. 5,568,409 (Neoh) assigned to the same assignee as the present invention, discloses a circuit for the implementation of the detection of a pointed object upon a touchpad and technique for the removal of power form the circuitry when the pointed object has not been detected upon the touchpad.
U.S. Pat. No. 5,287,121 (Louis, et al.) discloses a graphics input device where a stylus is used on a mechanism resembling a joy stick to provide horizontal graphics signals to a graphics processor and a feature within the mechanism to sense pressure upon the stylus to generate vertical graphics information.
U.S. Pat. No. 5,508,719 (Gervais) discusses a pressure activated pointing device for mobile or portable computing systems, where the output signals are proportional to the pressure on the pointing device.
The use of multiplexers within an analog-to-digital converter circuit is well known in the art. U.S. Pat. No. 5,446,371 (Eccleston, et al.), U.S. Pat. No. 5,150,120 (Yunus), U.S. Pat. No. 5,187,481 (Hiller), U.S. Pat. No. 4,656,585 (Stephenson), U.S. Pat. No. 4,616,325 (Heckenbach, et al.), and U.S. Pat. No. 4,196,358 (Conover, et al.) describe various applications of analog and digital multiplexing circuits for use within analog-to-digital converters.


A method is provided for producing an n-type or p-type epitaxial layer using a doped substrate material. The method includes growing a substrate (12), preferably from a material to which an epitaxial layer can be lattice-matched. The substrate (12) is doped with a predetermined concentration of dopant (14). Preferably, the dopant (14) possesses the ability to rapidly diffuse through a material. An epitaxial layer (16) is grown upon the doped substrate (12). The epitaxial layer (16) and the doped substrate are annealed, thereby causing the dopant (14) to diffuse from the substrate (14) into the epitaxial layer (16).

Many useful devices can be formed from thin epitaxial layers of semiconducting material grown on a substrate. For example, infrared detectors can be made from epitaxial layers of mercury cadmium telluride (HgCdTe) formed on a cadmium telluride (CdTe) or cadmium zinc telluride (CdZnTe) substrate. The electrical properties of an epitaxial layer depend in part upon whether the layer is formed as n-type material or p-type material. Because different types of devices require different electrical properties, the ability to create n-type or p-type materials in a controlled manner is very important.
N-type and p-type material may be formed by doping an epitaxial layer during either the growth of the layer or after growth. For example, dopants or impurities may be introduced into an epitaxial layer as the layer is grown by techniques such as liquid-phase-epitaxy (LPE), molecular beam epitaxy (MBE), vapor phase epitaxy (VPE), which include hot-wall epitaxy (HWE), chemical vapor deposition (CVD), metal-organic CVD (MOCVD), metal-organic vapor phase epitaxy (MOVPE), and organo-metallic vapor phase epitaxy (OMVPE). After the growth of the epitaxial layer, dopants may be introduced into the layer by techniques such as ion implantation and diffusion, or by the use of a diffusion source. The dopants for the epitaxial layer can be chosen to create either n-type or p-type layers, or distinct regions of n-type or p-type material within a layer.
In prior methods, an epitaxial layer was doped using either relatively slow diffusing dopants or intrinsic defects native to the epitaxial layer, such as vacancies created by post-growth annealing processes. Although it was recognized that rapidly diffusing dopants or impurities could be used to extrinsically dope the epitaxial layer, rapidly diffusing impurities were avoided for the following reasons. Because rapidly diffusing impurities tended to migrate to the substrate, the surface of the epitaxial layer, or the interface between the epitaxial layer and the substrate, these impurities would not uniformly disperse throughout the layer. Furthermore, an electrical p-n junction could be created between epitaxial layers by doping one layer with an n-type dopant and doping another layer with a p-type dopant. If a rapidly diffusing n-type or p-type dopant was used, however, such dopant would migrate between the layers. In other words, it was difficult to localize and uniformly distribute a rapidly diffusing impurity in a specific layer.
Accordingly, a need has arisen for a method for the controlled doping of epitaxial layers and related materials to create uniform n-type and p-type material.

Method for doping epitaxial layers using doped substrate material


Pieces of meat are cooked and then separated from a bouillon and cooled to at least a refrigeration temperature. A thickening agent is mixed with a sauce, which may include the bouillon as an ingredient, at a temperature of from 60.degree. C. to 80.degree. C., and the mixture is cooled and allowed to stand to gel the thickening agent to obtain a gelled sauce which is mixed with the meat pieces and formed into a block which then is frozen. The frozen block is packed in a tray package together with at least one vegetable. The thickening agent is a gelling agent which breaks down at a temperature at which the frozen block is heated for consumption so that upon heating for consumption, the meat and sauce mixture spreads out.

The present invention relates to a frozen meal, more particularly to a process for preparing a frozen meal containing meat pieces and one or more vegetables.
In the preparation of frozen meals for the food service industry such as aircraft meals containing meat with, for instance, potatoes and vegetables, pieces of meat are mixed with a cooked sauce, pressed in a standard former into a block, and then frozen and packed with the potatoes and vegetables in alu-trays. The product is normally heated in a convection oven for serving in a tray.


A flash sterilization container (10) comprises a pan (12) forming the bottom of the container holding a tray (14), with a cover (16) forming the top of the container, and a filter element (20). The filter (20) covers an opening in the cover (16) so that the inside of the container (10) formed when the cover is removably sealed to the pan (12) can communicate with the atmosphere surrounding the sealed container allowing steam to enter and exit the container passing through the filter (20). Items to be sterilized are placed on the tray (14) and the cover (16) is attached and sealed to the pan (12). The sealed container in then placed in an autoclave or other source of pressurized steam. The filter (20) allows the steam to enter the interior of the container and sterilize any items contained therein. After sterilization, the container (10) is removed from the autoclave and any remaining steam escapes from the interior of the container through the filter (20). The filter is composed of a material which will allow the pressurized steam to pass through but which is relatively impervious to dust and microorganisms thereby maintaining the sterility of the interior of the container and it's contents. Examples of suitable filter materials are: paper; TEFLON.RTM.; hydrophobic material, such as GORE-TEX.RTM.; porous stainless steel and polysulfone. The filter (20) can be held in place with a filter retainer manufactured as a permanent part of the cover (16) or incorporated into a filter cartridge which is removably attached to the cover.

1. Field of the Invention
The invention relates, in general, to a method for sterilizing medical instruments with steam and, in particular, to a sterilization container useful for flash sterilization which includes a filter that permits maximum steam penetration and prevents microorganisms and dust from entering.
2. Description of Related Art
Steam sterilization is a common method used for the sterilization of items, especially medical instruments by processing the items in an autoclave and exposing them to high pressure steam. This method requires the wrapping of individual items, heating the items with steam and then waiting for a drying/cooling period. Often during surgical procedures commonly used instruments need to be quickly sterilized after use or inadvertent contamination. Under such circumstances the standard autoclave method would take too long. An alternative sterilization method, which can be used under these circumstances, is known as flash sterilization. In flash sterilization metal instruments are not wrapped and are heated directly by the steam allowing sterilization in a reduced period of time. One drawback to the use of flash sterilization is the lack of a drying period. When the items are still moist and hot from sterilization, microorganisms and dust can contaminate the items when they are transported from the autoclave/sterilizer.
One common design for containers for flash sterilization is described in U.S. Pat. Nos. 5,097,865 and 4,748,003. Such containers use valves which require greater than atmospheric pressures to open the valves and allow the high pressure steam to enter the container but are closed under normal pressure conditions. This approach has a number of disadvantages. Such containers must be opened to allow the steam to escape, thus breaking the sterile field. Even if kept sealed, these containers cannot maintain the sterile field for longer than 24 hours. Also, the high temperature, high pressure valves needed for this method are very complex and very expensive.
The present invention facilitates the use of flash sterilization while retaining the advantage of standard autoclave sterilization by maintaining the sterility of the items in the sterilization container. Instead of a costly, complicated valve system the present invention uses a passive filter system which is capable of allowing steam to enter and exit the container and still keeping microorganisms and dust out, maintaining the sterile field in the container for long term storage.


A lens hood for a camera lens has a mounting barrel and a holding ring. The mounting barrel is hollow, is movably mounted around the camera lens and has an internal surface, a front end, a rear end, a sliding recess and at least one detent. The sliding recess if formed in the internal surface of the mounting barrel and has two ends. The at least one detent is formed adjacent to, communicating with and deeper than the sliding recess; two detents may be formed respectively at the ends of the sliding recess. The holding ring is resilient, is mounted securely around the cameras lens, is mounted in and presses the sliding recess and is selectively mounted in the at least one detent to allow the holding ring to relax and prolong usage lifetime.

1. Field of the Invention
The present invention relates to a lens hood, and more particularly to a lens hood for a camera lens.
2. Description of Related Art
With reference to FIG. 6, a conventional lens hood (50) is movably mounted around a camera lens (40) to shade a lens from external light sources and to avoid the external light source adversely affecting a final image by glare and lens flare. The conventional lens hood (50) has a mounting barrel (51) and a holding ring (52). The mounting barrel (51) is mounted around the camera lens (40) and has an internal surface (511). The holding ring (52) is mounted securely on an external surface of the camera lens (40) and is pressed against the internal surface (511) of the mounting barrel (51) to hold the mounting barrel (51) on the camera lens (40) using friction.
However, the internal surface of the mounting barrel (51) has a constant diameter, so the holding ring (52) is pressed by the internal surface (511) of the mounting barrel (51) against the external surface of the camera lens (40), and the holding ring (52) may wear down after prolonged use and cannot hold the mounting barrel (51) on the camera lens (40) securely. Therefore, lifetime of the conventional lens hood (50) is dictated by the holding ring (52). In addition, if the holding ring (52) is made to be replaceable, this will increase cost of production.
The lens hood for a camera lens in accordance with the present invention mitigates or obviates the aforementioned problems.


A modular raceway outlet station for use with a trunking duct which has a divider wall and a top access opening, includes an offset power box having a projection extending lateral from a top wall of the box having a top portion and an abutment portion which depends from the furthest extent of the top portion and is adapted to be substantially aligned with an edge of the top access opening, wherein the abutment portion does not project into the top access opening; and an opening formed in the abutment portion of the projection which communicates with an aperture formed in a side wall of the box adjacent the duct. The outlet station further includes, an extension which is adapted to extend over the top access opening having an abutment surface which aligns flush against the abutment portion of the projection; a routing notch formed in the abutment surface corresponding in longitudinal extent to the opening formed in the abutment portion of the projection; and a guide wall depending from the extension, interiorly adjacent the routing notch, having a longitudinal extent greater than the routing notch, and adapted to be substantially vertically aligned with the divider wall. Wherein, the power conductors may be routed out of and over the duct, and into the offset power box before installation of the extension and the power conductors remain completely isolated from the communication conductors after the extension is installed.

Multi-channel wiring raceway systems have become common practice for installation of power and communication conductors within the same duct. These raceway systems are usually used in an office, commercial, or industrial setting where design, layout, production, seating arrangements, and equipment requirements are constantly changed or upgraded. Flexibility and adaptability in these constantly evolving environments makes the surface mount raceway system the preferred method over conductors installed within the walls of a building. However, when a change or modification is required, the power and/or communication outlets usually must be moved, rearranged or supplemented.
Previous wiring plans and raceway systems, by design, inhibit changes or modifications. In an office environment, each desk, cubicle or seating location requires not only power outlets but also communication outlets, and usually more than one of each. Computers, telephones, facsimile machines, modems, transcriber machines, printers, fans and typewriters are examples of some of the office equipment which requires a plurality of each type of outlet. To accommodate the connectivity needs of the many machines, often many power and communication outlets are positioned at each location. Thus, the ability within the raceway system design to place power and communication outlets where most needed, when required, is of utmost importance.
Previous designs have unsuccessfully addressed the problems and complications with a variety of proposed solutions, none of which increase the ease or speed of installation. Positioning the power outlet along a central axis of the raceway occupies a considerable amount of space in the communication channel, effectively reducing the total capacity thereof. Other designs which position the power outlet box offset from the raceway commonly use a base plate which forms the bottom of the power outlet box and extends laterally across the raceway, covering all of the channels thereof. A major disadvantage of this design includes the inability to safely, functionally connect the power outlet such that it may be sealed and operational while the other channels of the raceway remain easily accessible for routing of cables. Consequently, all other cables which are to be installed have to be fished through, underneath the base plate covering the raceway, or cut and spliced at the junction, rather than being simply laid in the proper channel. This problem is often enhanced when two different installers are required for the power and communication connections.
Other disadvantages include increased time and difficulty of installation, cumbersome to maneuver cables and equipment around the base plate, no electrical power available until the electrical installer and communications installer have completed their jobs, and power conductors not isolated from communication conductors until installation is completed.
Therefore, in the design of raceway systems, more economical, easier to install outlet stations are desired, and improvement in the art of raceway modular power and communication outlets is needed.


According to an aspect, there is provided a method of operating a first radio access node in a communication network, the method comprising determining whether a first base key that is used to determine a first encryption key for encrypting communications between a communication device and the first radio access node can be used by a second radio access node for determining a second encryption key for encrypting communications between the communication device and the second radio access node; and if the first base key can be used by the second radio access node, sending the first base key to the second radio access node during handover of the communication device from the first radio access node to the second radio access node.

In Long Term Evolution (LTE) communication networks, the communications between the user equipment (UE) and an eNB are encrypted and partially integrity protected. The integrity and encryption keys are derived from a common root key called the KeNB which is shared between the UE and the eNB. The KeNB is unique to the UE-PCell pair, where PCell is the primary cell that the UE uses as a 'master' cell when communicating with an eNB. Since the UE only uses one PCell for communicating with an eNB, the KeNB is also unique for the UE-eNB pair. That is, the same KeNB is never used to protect the traffic between the UE and two different eNBs. The rationale behind this design is to prevent an attacker that has gained access to or knowledge of a KeNB that is used between a UE and a first eNB to have any use for that KeNB when attempting to break encryption or integrity on traffic between the UE and a different eNB.
To ensure that the KeNB is unique per UE-eNB pair, KeNB is changed during handover between two eNBs. For simplicity, KeNB is actually changed on all intra-LTE handovers (e.g. handover between cells), even when the source eNB and target eNB is the same node.
The uniqueness of the UE-KeNB pair during handover is achieved by the fact that the UE and source eNB derive a new KeNB (denoted KeNB*) from the current KeNB, the Physical Cell Identifier (PCI) of the target primary cell (PCell) and the target physical cell downlink frequency (e.g. the Evolved Absolute Radio Frequency Channel Number for the downlink, EARFCN-DL). This is specified in clause 7.2.8 of 3GPP TS 33.401 "3GPP System Architecture Evolution (SAE); Security architecture", version 12.14.0 (2015-03).
More specifically, the input to the key derivation function (KDF) to derive KeNB* is:                FC=0x13        P0=PCI (target PCI)        L0=length of PCI (i.e. 0x00 0x02)        P1=EARFCN-DL (target physical cell downlink frequency)        L1 length of EARFCN-DL (i.e. 0x00 0x02)
A handover between two eNBs without core network involvement, a so-called X2 handover, is described below with reference to FIG. 1. Handovers can be performed after the UE has completed all necessary procedures to activate Radio Resource Control (RRC) and Non-Access Stratum (NAS) security. The X2 handover is initiated by the source eNB 2 calculating a KeNB* key from the currently active KeNB, shared between the source eNB 2 and the UE 3, and sending it together with the UE security capabilities to the target eNB 4 in a handover request message 5. The target eNB 4 replies with the required configuration information 5 for the UE connection. This information includes the chosen algorithms that the target eNB 4 and the UE 3 shall use. The source eNB 2 then forwards the reply to the UE 3 (signal 6), and the UE 3 confirms the handover with a completion message 7 to the target eNB 4. In the last step, the target eNB 4 retrieves a new key called the Next Hop key (NH) from a Mobility Management Entity (MME). The NH is derived from a key KASME (a base key that is shared by the UE and MME) and the NH is used as a basis for the calculation of KeNB* in the next handover event.
In some scenarios the source eNB doesn't have a "fresh" NH key when performing a handover, and instead the eNB can create a new KeNB* from the current KeNB. This is called a vertical key derivation. An NH key is referred to as being "fresh" when it has not previously been used.
The KeNB* key itself is not sent from the eNB to the UE, and instead an information element (IE) indicating whether the KeNB* is derived vertically (i.e. a fresh NH exists) or horizontally (no new NH exists in the eNB) is sent to the UE. This is information element is called NCC (Next-hop Chaining Counter) and is included in the RRC reconfiguration message. The NCC is a value between 0-7. If the NCC is stepped, then the UE knows that a vertical key derivation shall be performed, and when the NCC is the same as the NCC associated with the currently active KeNB, the UE will instead perform a horizontal key derivation.
A trend in today's networks is for the operator to add more frequencies and reduce the size of cells to increase the capacity of mobile broadband. This leads to an increase in UE reconfigurations and mobility actions.
The ability to quickly move or resume a UE session between cells becomes increasingly more important in order to fit the traffic patterns associated with short data bursts. However, since the encryption and integrity keys are derived from a base key (KeNB) that is tied to the primary cell (via the use of the EARFCN-DL of the primary cell and the PCI in the derivation of the key KeNB), each time the UE moves from that PCell or reconnects in another PCell a key renegotiation must be performed before traffic can resume. This causes a problem since re-negotiation of the KeNB consumes considerable processor cycles and memory, and in particular results in the encryption and integrity keys having to be derived from the new KeNB. When the encryption key is updated, some already encrypted packets must be buffered, decrypted using the old encryption key and then re-encrypted using the new encryption key. An analogous problem is that already integrity protected packets similarly need to be re-protected using the new integrity protection key. This adds delay that reduces the end-user experience. Moreover, it complicates the implementation of the eNB, leading to increased risk for implementation errors and increased cost for code maintenance.
The problem above is described in the context of the way security is handled in LTE, although the problem may also be evident in other types of communication networks. It will be appreciated that the need to optimise security processing is common to many different types of network.
Therefore there is a need for improvements in the way in which security is handled when a handover occurs between two eNBs.

Nodes for use in a communication network and methods of operating the same