A novel process for producing a dry preform for a composite material takes advantage of the fact that a reinforcing filament assembly, when consisting of a fiber reinforcement layer a, formed by stringing a first set of parallel strands of fiber reinforcement over a part or all of the plane within any desired shape along the straight axis 2, and a fiber reinforcement layer b, formed by stringing a second set of parallel strands of fiber reinforcement over the plane at an angle θ with respect to the straight axis 2, such that 0°<θ<180°, the part of the reinforcing filament assembly that consists solely of the fiber reinforcement b can be deformed as desired. According to this process, strands c of fiber reinforcement are strung using a fiber reinforcement string jig as shown in FIGS. 8(A) and 8(B). The layers of the strung strands of fiber reinforcement are brought together by a simple means such as stitching. The integrated layer is then shaped into the reinforcing filament assemblies 3, 4, which are combined to form a dry preform 1 for making a composite material having any desired alignment of fiber reinforcement.

1. Field of the Invention
The present invention relates to a method and an apparatus for producing dry preforms for composite materials that exhibit an improved ability to be shaped into a curved shape required in various structures, including those used in aeronautic and space applications, architectural structures, automobiles, ships and other applications in which mechanical strength is of significant importance.
Hereinafter, the term "dry preform" is used to mean a fiber-made structure that has not been impregnated with a resin so that it can be formed into a desired shape by various forming processes including resin transfer molding (RTM), resin film infusion (RFI) and vacuum assist resin transfer molding (VaRTM).
2. Description of the Related Art
Lightweightness and high strength are general requirements for structures used in aircrafts and spacecrafts, architectural structures, automobiles, ships and other applications in which significant mechanical strength is required.
Traditionally, structural materials of airplanes, in particular those used to form curved structures and structures with continuously varying thicknesses and widths, have been formed of metal materials to provide a mechanical strength required for the particular structure. A large number of parts of significant weight must be used in these structures to provide a necessary strength by metal materials, adding to the weight of the airplane. Not only does this impose a significant limit on the design of airplanes, but it also leads to a considerable increase in the fuel consumption during actual flights of an airplane. For these reasons, developing lightweight materials has been a key factor in designing and manufacturing airplanes as well as in minimizing the operational costs of airplanes.
Many of recent studies conducted on structural materials of airplanes are directed to the development of fiber-reinforced composite materials with a high specific strength. Such materials are generally produced by impregnating a proper fiber reinforcement, such as glass fiber, aramide fiber, and carbon fiber, with an epoxy resin or other polymer matrices. Many of these materials have actually been put to use. Composite materials are considered superior to metal materials because of their high specific strength and high specific rigidity. Their anisotropic property, a unique characteristic of fiber reinforced material, also permits a high degree of freedom in designing different structures. Furthermore, composite materials are suitable for making a large structural unit as a single piece and can thus permit a significant reduction in the number of parts and costs.
To manufacture these composite materials, a technique is known in which a fiber-reinforced material is obtained by placing a plurality of pipes along the direction of the thickness of the material in a pattern corresponding to a desired shape, stringing strands of fiber reinforcement from one pipe to another in a zigzag fashion, and replacing the pipes with fibers that extend along the direction of the thickness to hold the strands of fiber reinforcement together (See, for example, Japanese Patent Laid-Open Publication No. Sho 59-47464). This technique, however, is not efficient since the strands of reinforcement fiber in a zigzag fashion need to be strung one at a time, which takes a considerable amount of time. Replacing the pipes with strands of fiber reinforcement that extend across the thickness further adds to the time and costs required by the process.
Also, a technique is known for producing a fiber-reinforced curved material with a complex cross-sectional shape (See, for example, descriptions of U.S. Pat. No. 5,914,002 and accompanying drawings). In this technique, strands of fiber reinforcements are arranged along straight lines and no strands are aligned to the desired curve. The fiber-reinforced material produced in this manner does not have sufficient mechanical strength.
When it is desired to form a fiber reinforced body that has a complex cross-sectional shape, such as a ring or any other curved shape, part or all of which is formed by a curve, the hand lay-up process for instance is employed. In this process, a material called prepreg, which is a fiber reinforcement pre-impregnated with a resin, is cut into small pieces of sheets, which are overlaid on top of one another to form a body of desired shape (See, for example, Japanese Patent Laid-Open Publication No. Hei 07-081566). A drawback with this technique is that most of the process needs to be carried out manually: the process is too complicated to be automated. This technique involves too many steps and requires significant amounts of time. Also, materials are wasted in large quantity in this process. Thus, the overall productivity of the process remains low. In this process, reinforcing fibers are provided in the form of ring-shaped or curved short fragments. This not only results in an insufficient mechanical strength of the structural material obtained by the process, as compared to structural materials reinforced by continuous strands of fiber reinforcement, but it also leads to a significantly increased cost.
In another technique for producing a fiber-reinforced material, strands of fiber reinforcement are strung to form a desired fiber arrangement with predetermined width and thickness, and the resulting fiber arrangement is unified, for example, by stitching to form a desired fiber-reinforced material (See, for example, description of U.S. Pat. No. 5,809,805 and accompanying drawings). Essentially, this technique is designed to produce intermediate preform substrates, which are subsequently formed into the final shape. Thus, it is difficult to directly obtain desired shaped products using this technique alone since the intermediate substrates require additional processing, such as cutting and overlaying, before the desired final shape is achieved. This makes the process rather complicated and costly.
A technique, known as the automated tape lamination (ATL) or the fiber placement process, that also makes use of a prepreg material is in practical use in the production of large components that have curved surfaces, such as those used as skin materials of aircrafts and rockets (See, for example, description of U.S. Pat. No. 6,096,164 and accompanying drawings). One disadvantage of this technique is that it cannot be used to make shaped bodies with an I-, L-, T-, hat-shaped or other complex cross-sections.
Processes that utilize fiber-reinforced fabrics are also known. In these techniques, fabrics are formed into a disk, a helix or other desired shapes (See, for example, Japanese Patent Laid-Open Publication Nos. Sho 57-133242, Hei 10-217263, Hei 09-207236, 2001-073241, Hei 07-133548, and 2002-3280). Each of these techniques, however, requires an extra step to form fibers into a fabric and thus is not cost-efficient. Also, these techniques involve many processes such as cutting and overlaying fabrics and require a significant amount of effort in precisely controlling the number of fibers in different areas of a fabric. As a result, each of these techniques tends to be costly.
Fiber-reinforced fabrics that take advantage of strands of fiber reinforcement with a complex cross-sectional shape, such as I-, H-, or T-shaped cross-section, are also known (See, for example, Japanese Patent Laid-Open Publication No. Sho 57-133241). Being a fabric woven on a weaving machine, this material permits only a limited number of arrangements of strands of fiber reinforcement: it is difficult to arrange fibers in a desired area and in a desired orientation. In addition, strands of fiber reinforcement aligned in the fabric material are crimped, leading to the insufficient strength of the material.
Techniques are also known in which fiber structure of a fabric is altered to make a curved structure (See, for example, Japanese Patent Laid-Open Publication Nos. Sho 63-120153 and Hei 02-191742). Fibers are also crimped in the fabric material used in these techniques and, as a result, the strength of the material is reduced. The techniques also involve many steps. Thus, these techniques are not suitable for mass production and can only achieve limited shapes of the products.
A process is also known that makes use of a braided material, which consists of interlaced strands of fiber reinforcement, to make a composite material (See, for example, Japanese Patent Laid-Open Publication No. Hei 10-290851). Although a typical braided material is deformable since it consists of fibers that are directed in two intersecting directions and are interlaced with each other, the deformability of the material is lost when fibers aligned in other directions are included to restrict the movement of the interlaced fiber reinforcements. Furthermore, the additional fibers may increase the unfavorably oriented strands of fiber reinforcement. Accordingly, not only does the process permit a limited degree of freedom in designing shaped products, but the weight and the size of the products are also increased in the process. Fibers are crimped in any of fabrics, braids and knits, reducing the strength of the products and making the process just as costly as the process using fabric. In addition, the strength required for a particular design of the structural material may sometimes not be obtained. Each of these problems has contributed to the delay in application of composite materials to commercial aircrafts (See, for example, Japanese Patent Laid-Open Publication No. 2000-328392).

Method for producing dry preform for composite material


A “data plant” accepts power-generation-capable raw materials and outputs processed data. The processed data can be delivered to consumers more efficiently than other forms of power transfer, including power transfer through electricity, steam, physical motion, and the like. Consequently, data plants can be located where power-generation-capable raw materials can be obtained inexpensively, for free, or where power-generation-capable raw materials are waste products for which the operator of the data plants can be compensated for processing. Self-powered data plants need not even be continuously fed with power-generation-capable raw materials and, if such data plants receive and output data via wireless communications, the self-powered data plants can require no physical connection or attachment at all. For example, a single piece of silicon comprising a silicon solar cell that generates electrical power and silicon circuitry that consumes it to perform data processing can be a silicon self-powered data plant.

The modern electrical grid, through which modern society receives and accesses electrical power, has become so ubiquitous that its context often becomes lost. And that context is, simply, that the modern electrical grid is nothing more than a mechanism by which to transfer power from places where power can be generated to places where power can be conveniently consumed and utilized. But the mere ubiquity of the modern electrical grid does not necessarily mean that it is the most efficient mechanism for transferring power.
Three hundred years ago, early settlers in the Western region of modern-day New York State sought to harness at least some of the power of Niagara Falls. Early attempts to do so were based on the mechanical transmission of power. For example, in the late 1750's, some of the power of Niagara Falls was harnessed to turn waterwheels, which were connected to a sequence of belts, which turned equipment in a local sawmill. Thus, the sequence of belts transferred power, in the form of rotational motion, from the location at which such power was generated, namely by the water turning a waterwheel, to another location where such power could be utilized, namely the sawmill. Needless to say, the transfer of power through a sequence of belts, in the form of rotational motion, comprises inherent limitations in how far such power can be transferred.
To improve upon this power delivery, electrical generators were installed at Niagara Falls in the early 1880's. These electrical generators transferred power in the form of direct current electricity. As will be recognized by those skilled in the art, direct current electricity, much like the sequence of belts, was not able to transfer power for long distances. What was ultimately selected to transfer power from Niagara Falls, where the movement of the water inherently comprises power generation capability, to places where that power could be conveniently utilized, such as the nearby town of Buffalo, N.Y., was alternating current electricity. As is well known to electrical power history buffs, in the mid-1890's, Westinghouse, using Nikola Tesla's invention, installed alternating current electrical generators at Niagara Falls and transmitted power using alternating current electricity. The modern electrical power grid is based on this very same three-phase alternating current that was utilized to deliver power from Niagara Falls to, for example, Buffalo N.Y. Thus, contextually, the modern electrical power grid is nothing more than the most efficient method of delivering power across distances in the 1880's.
As electrical power delivery became ubiquitous, a greater quantity of devices were made available that could convert such electrical power into useful results. For example, an electrical heater can be plugged into the electric power grid and can utilize electrical power received from the grid to generate a useful result, namely heat on a cold day. Were heat the only useful byproduct that could be generated, more efficient power delivery mechanisms could be utilized. For example, many cities and universities in cold climates have a centralized steam power plant that utilizes power-producing raw materials, such as coal or natural gas, and then delivers the power derived from those raw materials in the form of heat, transported via steam in steam pipes running through steam tunnels. Consequently, in such cities and universities, rather than plugging in a heater into the electrical power grid, residents can simply increase the amount of steam flowing through a steam radiator. In both instances, power was transmitted from a power generation facility to a consumer of power that utilized that power to warm their living space. In the first example, the power was generated at an electrical power plant and then transmitted in the form of electrical power, through the electrical power grid, to a user that utilized a device, namely an electrical heater, to generate a useful result, namely heat. In the second example, the power was generated at a steam power plant and then transmitted in the form of heat power, or steam power, through the network of steam pipes in steam tunnels, to a user that utilized the device, namely a steam powered heater, to generate a useful result, namely heat.
Of course, the modern electrical power grid can provide power for many other types of electrical devices, beyond simply electrical heaters, that can generate other types of useful results. For example, electrically powered entertainment devices provide audio/visual entertainment, electrically powered lamps provide light, electrically powered shavers provide hair trimming, and so on. In each case, the power obtained from power-generation-capable raw materials was transmitted, via the electrical power grid, and utilized to generate a useful result.
Increasingly, one useful result generated by electrically-powered devices is the processing of digital data by electrically-powered computing devices. Personal computing devices are electrically powered because, at the time that personal computing devices were initially developed, and still to this day, alternating current electricity represents the most ubiquitous form of power distribution. The circuitry inside a personal computing device, and, indeed, in enterprise computing devices as well, such as server computing devices, natively operates on direct current electricity. As will be recognized by those skilled in the art, power supplies convert alternating current electricity that is provided by the electrical power grid into the direct current electricity that can be consumed by the circuitry inside of a computing device that actually performs the digital data processing.
Because digital data communications over short distances were substantially faster than those over long distances, the processing of digital data was typically performed at the location where the digital data was created, and ultimately consumed by the user of a computing device. Thus, for example, traditionally, the processing of digital data performed by individual users utilizing personal computing devices was performed by those personal computing devices themselves, which were co-located with the user. Similarly, as another example, traditionally, the processing of digital data performed by enterprise users utilizing enterprise computing devices, such as server computing devices, was performed by those server computing devices themselves which were located in one or more of the facilities that also housed the enterprise.
As computer network communications have increased in efficiency and bandwidth, it has become more practical to perform digital data processing at a location remote from the location where such data is initially generated, and where the processed data will be consumed. For example, a user can upload a digital photograph to a server and then cause the server to process the digital photograph, changing its colors and applying other visual edits to it. In such an example, of the digital processing that is being performed is being performed by a device that is remote from the user. Indeed, in such an example, if the user was utilizing a battery-operated computing device to interact with the server such as, for example, a laptop or smartphone, the user could be in a location that was not receiving any electrical power at all. Instead, electrical power can have been delivered to the server, which is remote from the user, and the server can have utilized electrical power to process the data provided by the user and then return the processed data to the user. In such an example, the user was able to perform processing on digital data without receiving any electrical power and instead, receiving, only the result of the work performed by electrical power, namely the processed data that was performed by the server computing device that has consumed electrical power that was delivered to the location where the server was located.
As will be recognized by those skilled in the art, such remote data processing is increasingly performed by collections of computing devices that are commonly referred to as a "data center". Efficient network communications enable individual users, and enterprises, to transmit data to such data centers, where the data can be stored, processed, and otherwise operated upon by the computing devices in the data center. Individual users and enterprises can then retrieve processed data from the data centers when needed. As will also be recognized by those skilled in the art, modern data centers consume a large amount of electrical power such that the cost of the electrical power consumed by the data center becomes a major, if not the primary, component in determining a data center's fiscal viability.

Data plant—a raw material powered data generator


A vehicle wheel assembly includes a tire, a rim, an air valve and a relief valve. The relief valve can be installed in the rim, in the tire, or incorporated into the housing of the air valve to communicate directly with the interior of the tire; or as an adapter attachable to the outer end of the air valve. The relief valve includes an aperture normally covered by pre-stressed flexible belt which seals the aperture, but upon the presence of excessive pressure in the tire is deforming to vent the excessive pressure to the atmosphere. A second described variation relief valve includes a weakened portion of its housing which is automatically ruptured upon the presence of excessive pressure; this variation provides a one-time venting adapter.

The present invention relates to vehicle wheel assemblies, and particularly to such assemblies which are provided with protection against excessive pressure in the vehicle tire.
Vehicle tires are designed to be pressurized at a predetermined air pressure according to the type of vehicle. Thus, the optimum pressure of the vehicle tire may range from about 26 PSI for passenger vehicles, up to about 125 PSI for heavy trucks. Air pressure pumps provided in service stations for adding pressurized air to a vehicle tire are therefore generally capable of pressurizing the tire well over 125 PSI.
Such air pressure pumps frequently include pressure meters which indicate the pressure of the vehicle tire being inflated, but generally include presettable pressure limiters which enable the user to preset the maximum pressures to be applied to the tire. However, if such a pressure limiter should malfunction, a very dangerous situation can be created where a vehicle tire, designed for e.g., 26 PSI, may be filled to a pressure of over 100 PSI. This may result in the bursting of the tire which can cause very serious injury to the person filling the tire particularly since the person's head is generally close to the tire being filled. In fact, there have been a number of cases of tire bursting resulting in serious injury, or even death, to the person filling the tire.

Vehicle wheel assemblies including protection against excessive tire pressure


The present invention provides a method for making a lithographic printing plate according to the silver salt diffusion transfer process comprising the steps of image-wise exposing an imaging element comprising on a support a photosensitive layer comprising a silver halide emulsion and an image receiving layer containing physical development nuclei and developing said imaging element in the presence of developing agent(s) and silver halide solvent(s) using an alkaline processing liquid characterized in that said development is carried out in the presence of a regulator according to one of the formulas as specified in the claims. The present invention further provides an imaging element and alkaline processing liquid for use in said method.

The principles of the silver complex diffusion transfer reversal process, hereinafter called DTR-process, have been described e.g. in U.S. Pat. No. 2,352,014 and in the book "Photographic Silver Halide Diffusion Processes" by Andre Rott and Edith Weyde--The Focal Press--London and New York, (1972).
In the DTR-process non-developed silver halide of an information-wise exposed photographic silver halide emulsion layer material is transformed with a so-called silver halide solvent into soluble silver complex compounds which are allowed to diffuse into an image-receiving element and are reduced therein with a developing agent, generally in the presence of physical development nuclei, to form a silver image having reversed image density values ("DTR-image") with respect to the black silver image obtained in the exposed areas of the photographic material.
A DTR-image bearing material can be used as a planographic printing plate wherein the DTR-silver image areas form the water-repellant ink-receptive areas on a water-receptive ink-repellant background. For example, typical lithographic printing plates are disclosed in e.g. EP-A-423399 and EP-A-410500.
The DTR-image can be formed in the image-receiving layer of a sheet or web material which is a separate element with respect to the photographic silver halide emulsion material (a so-called two-sheet DTR element) or in the image-receiving layer of a so-called single-support-element, also called mono-sheet element, which contains at least one photographic silver halide emulsion layer integral with an image-receiving layer in waterpermeable relationship therewith. It is the latter mono-sheet version which is preferred for the preparation of offset printing plates by the DTR method.
As for other printing plates it is required that the printing plates obtained according to the DTR-process have a high printing endurance, good ink acceptance in the printing areas and no ink acceptance in the non-printing areas (no staining). It is furthermore desirable that the number of copies that have to be disposed of because of ink acceptance in the non-printing areas (so called toning) during start-up of the printing process is limited. To obtain a printing plate of high printing endurance the wear of the printing areas on the printing plate should be as low as possible.
In addition to the above requirements the image on the printing plate should be of high contrast to ease the visual inspection of the printing plate. A lithographic printing plate obtained according to the DTR-process using a mono-sheet DTR-material having on a support a photosensitive layer comprising silver halide and an image receiving surface layer contains a reflective silver image in the image-receiving surface layer on a background of black less reflective silver in the photosensitive layer resulting from therein developed silver halide. As a consequence the contrast between the silver image and background silver may be poor so that visual inspection is more difficult.

Method for making a lithographic printing plate according to the silver salt diffusion transfer process


What is provided herein is a process for making homopolymers of polyvinylpyrrolidone polymer in the form of fine powders at a polymer solids level of at least about 17%, preferably 30% or more, and in a yield of at least about 95%, which comprises precharging a reactor with a predetermined amount of a solvent selected from a C.sub.3 -C.sub.20 alkane, preferably heptane, or a C.sub.3 -C.sub.20 cycloalkane, preferably cyclohexane, and a free radical polymerization initiator, and feeding vinylpyrrolidone monomer into the precharged reactor at a selected rate, preferably about 0.1 to 1.8 g vinylpyrrolidone/min/1000 g of solvent, and most preferably, about 1 g/min/1000 g of cyclohexane and 0.5 g/min/1000 g of heptane, which rates preclude build-up of monomer during the polymerization, and for a feed period which provides the desired level of polymer solids in the reaction product, preferably at least about 200 minutes. The polymer product may be isolated from the reaction mixture by filtration and drying, or by direct drying.

1. Field of the Invention
This invention relates to polymerization of vinylpyrrolidone to form polyvinylpyrrolidone polymers, and more particularly, to a precipitation polymerization process for preparing homopolymers of polyvinylpyrrolidone in high yield in the form of fine powders at a high polymer solids level.
2. Description of the Prior Art
Polyvinylpyrrolidone (PVP) can be made by solution, suspension or emulsion polymerization of vinylpyrrolidone monomer in the presence of water or organic solvents. Lorenz and Williams U.S. Pat. No. 4,190,718, for example, disclosed a process for making high molecular weight PVP in heptane by reverse suspension polymerization using suitable suspending agents. Belgium patent 668,368 also described a process for synthesizing copolymers of vinyl lactams in aliphatic hydrocarbon solvents by precipitation polymerization. However, these and other references have failed to provide a commercial process for making homopolymers of polyvinylpyrrolidone in high yield in the form of fine powders at a high polymer solids level.
Accordingly, it is the object of this invention to provide a new and improved process for making homopolymers of polyvinylpyrrolidone in high yield in the form of fine powders at a high polymer solids level.
A particular object herein is to provide homopolymers of polyvinylpyrrolidone in a yield of at least about 95%, as fine powders, preferably at a polymer solids level of at least about 17%, and, most preferably 30% or more.
These and other objects and features of the invention will be made apparent from the following description of the invention.


There is provided a clock distribution network for synchronizing global clock signals within a 3D chip stack having two or more strata. The clock distribution circuit includes, on each of the two or more strata, phase detectors, a logic circuit, and a phase de-skewing element. Each phase detector has a respective output for providing phase information relating to a phase difference between two of the global clocks signals on respective different ones of the two or more strata. The logic circuit is connected to the respective outputs of the phase detectors for determining a phase adjustment plan for a given one of the two or more strata upon which the logic circuit is located responsive to the phase information. The phase de-skewing element is for adjusting a clock skew of a same stratum located one of the two of the global clock signals responsive to the phase adjustment plan.

1. Technical Field
The present invention relates generally to integrated circuits and, in particular, to distributed phase detection for clock synchronization in multi-layer 3D stacks.
2. Description of the Related Art
A three-dimensional (3D) stacked chip includes two or more electronic integrated circuit chips (referred to as strata or stratum) stacked one on top of the other. The strata are connected to each other with inter-strata interconnects that could use C4 bump or other technology, and the strata could include through-Silicon vias (TSVs) to connect from the active electronics on one side of the stratum to the opposite side of the stratum. The active electronics can be on the "front" or "back" side of the stratum.
However, the synchronization of a global clock for the stacked chip poses a number of problems. These problems relate to a set of constraints that should be imposed on the synchronization. The set of constraints include, but are not limited to, the following: strata must be testable at the target clock frequency before stacking; inter-stratum and within stratum skews must be small over the entire clock mesh; low power and area overheads; applicable to both grid and non-grid clock networks; and capable of tracking layer-to-layer clock skew due to process, voltage, and temperature variations using a feedback loop.

Distributed phase detection for clock synchronization in multi-layer 3D stacks

INTERNATIONAL BUSINESS MACHINES CORPORATION


A getter pump module includes a number of getter disks provided with axial holes, and a heating element which extends through the holes to support and heat the getter disks. The getter disks are preferably solid, porous, sintered getter disks that are provided with a titanium hub that engages the heating element. A thermally isolating shield is provided to shield the getter disks from heat sources and heat sinks within the chamber, and to aid in the rapid regeneration of the getter disks. In certain embodiments of the present invention the heat shields are fixed, and in other embodiments the heat shield is movable. In one embodiment, a focus shield is provided to reflect thermal energy to the getter material from an external heater element and provide high pumping speeds. An embodiment of the present invention also provides for a rotating getter element to enhance getter material utilization.

This invention relates generally to ultra-high vacuum systems, and, more particularly, to in situ getter pumps used in semiconductor manufacturing systems.
There are a number of processes which require ultra-high vacuum levels of, for example, 10.sup.-7 to 10.sup.-12 Torr. For example, high vacuum physics machines such as cyclotrons and linear accelerators often require a vacuum of the order of 10.sup.-8 -10.sup.-12 Torr. Also, in the semiconductor manufacturing industry, ultra-high vacuums of approximately 10.sup.-7 -10.sup.-9 Torr are often required in semiconductor processing equipment.
Several pumps are often used in series or parallel to achieve ultra-high vacuum levels within a chamber. A mechanical (e.g. oil) pump is often used to reduce the pressure within a chamber to approximately 30-50 millitorr. These are often referred to as "high pressure" pumps since they only pump relatively high pressure gasses. Then, a high- or ultra-high vacuum pump, such as a molecular pump, cryopump, turbo pump, or the like, is used to reduce the pressure to approximately 10.sup.7 -10.sup.-9 Torr. These are often referred to as "low pressure" pumps since they pump low pressure gasses. The pump-down time for a particular chamber can range from minutes to hours to days depending upon such factors as the size of the chamber, the capacity of the pumps, the conductance from the chamber to the pumps, and the desired final pressure.
In certain ultra-high vacuum applications, getter pumps have been used in conjunction with the aforementioned mechanical, molecular, and cryopumps. A getter pump includes getter materials comprising metals or metal alloys which have an affinity for certain non-noble gases. For example, depending upon the composition and temperature of the getter material, getter pumps have been designed which preferentially pump certain non-noble gases such as water vapor and hydrogen.
For example, getter pumps provided by SAES Getters, S.p.A. of Milan, Italy, typically include getter material encased in a stainless steel container. Getter pumps can operate from ambient temperatures to about 450.degree. C., depending upon on the species of gas to be pumped, the getter composition, etc. A preferred getter material for prior art SAES getter pumps is St 707 getter material (which is an alloy of Zr-V-Fe) and which is produced by SAES Getters, S.p.A. of Milan, Italy. Another such material is St 101.TM. getter alloy, also available from SAES Getters, S.p.A., which is an alloy of Zr-Al. Some of these prior art getter pumps can be considered in situ pumps in that they are disposed within the high vacuum physics machines.
Some present getter pump designs employ getter devices comprising metal ribbons coated with a powdered getter material such as the St 707 and St 101.TM. getter alloys just described. The coated ribbons are pleated in a concertina fashion to increase the ratio of exposed surface area to the volume occupied by the coated ribbon, and to increase adsorption of desired gasses. Such pumps are manufactured by SAES Getters, S.p.A., and sold under the trade name SORB-AC.RTM.. In addition, recent designs have employed disk-shaped substrates coated with getter material powders. Designs using coated substrates have a drawback in that the total amount of getter material available for sorption is limited to the nominal surface area of the getter device substrate.
It is has been suggested that getter pumps be provided for semiconductor processing equipment. For example, in an article entitled "Non-Evaporable Getter Pumps for Semiconductor Processing Equipment" by Briesacher, et al., and published in Ultra Clean Technology 1(1):49-57 (1990), it is suggested that any application which uses getters to purify processed gases for semiconductor processing can also utilize non-evaporable getter pumps for in situ purification and for the selective pumping of impurities.
The aforementioned Briesacher reference discloses that there are two possible operating scenarios for the use of getter pumps in a sputtering system, which is a type of semiconductor processing equipment. The first is the addition of the getter pump to the system to operate in parallel with conventional pumps (e.g. mechanical and cryopumps) of the system. In this scenario, the operation of the system is not modified in any way, and the getter pump merely serves as an auxiliary pump to lower the partial gas pressure of certain components of the residual gas in the chamber. The second scenario requires filling the chamber to a pressure in the range of 3.times.10.sup.-3 to 6.times.10.sup.-3 Torr, stopping the argon flow into the chamber, and sealing the chamber. The getter pump is then said to act as an "in situ" purifier for the argon. However, as discussed below, the pump is not truly "in situ" in that the active material is not within the volume of the processing chamber.
In a typical sputtering system, a noble gas (usually argon) is pumped into a chamber and a plasma is created. The plasma accelerates positively charged argon ions towards a negatively charged target, thereby causing material to become dislodged and to settle on the surface of the wafer. Getter pumps are well adapted for use with sputtering systems, since the only desired processing gas is a noble gas which is not pumped by the getter pump. Therefore, the getter pump can remove impurity gases from a sputtering chamber without affecting the flow of the noble gas required for the sputtering process.
The Briesacher reference was primarily an academic analysis of the practicality of using non-evaporable getter pumps in semiconductor processing equipment. Therefore, very little practical application of the theory is disclosed. Furthermore, while the Briesacher article uses the term "in situ" to describe a scenario for the use of a getter pump, it is clear from the description that the getter pump is external to the chamber and is considered "in situ" only in the sense that when the chamber is sealed and when no argon is flowing into the chamber, the volume within the getter pump can be considered to be connected to the chamber volume. According to the analysis presented by Briesacher, a valve must be placed between the getter containment vessel and the main chamber to protect the getter from atmospheric exposure that would deteriorate the getter and require additional regenerations. Such protection is imperative with the strip-type getters discussed in the Briesacher reference. Thus, the getter described by Briesacher is not truly "in situ" in that the getter pump surfaces are within a volume that is connected to the chamber volume through a restrictive throat, which greatly limits the conductance between the chamber and the pump. By "conductance" it is meant herein the ease with which a fluid (gas in this instance) flows from one volume (e.g. the processing chamber) to another volume (e.g. the pump chamber). Conductance is limited by the aperture size between the two chambers, which is typically the cross-sectional area of the throat of the cryopump.


A system for supply of power source currents, the system includes: a power source input terminal configured to be supplied with a power source current; a plurality of power source output terminals, coupled to the power source input terminal in parallel, configured to output a power source current; a protecting circuit configured to protect a supply of a excessive power source current to the power source input terminal; a plurality of data signal terminals each corresponding to one of the plurality of power source output terminals; and a connector coupled to at least one pair of one of the plurality of power source output terminals and one of the plurality of data signal terminals.

An apparatus coupled via an interface according to a standard related to supply of power source currents is supplied with a power source current. As being connected via the interface according to the standard possibly without an embedded battery, an AC power source or the like, the apparatus may be downsized or be trimmed weight. A personal computer (PC) or something may be provided with a plurality of interfaces according to the standard related to supply of power source currents. A system for supplying the PC with a power source current via the interface may be installed on the PC.
A related art is disclosed in Japanese Laid-open Patent Publication No. 2009-75902 and International Publication Pamphlet No. WO 2005/022369.

System for supply of power source current, connector and method of supplying power source current


A reduced-size VCO/PLL module including a circuit board having a plurality of components positioned, mounted and interconnected thereon in a manner allowing the same to fit in a 10.5 mm×14 mm×2.9 mm package. In one embodiment, an inner lid encloses the VCO portion of the module. In all embodiments, an outer lid is adapted to cover all of the components on the circuit board of the module. The inner and outer lids include tabs adapted to be fitted within respective apertures defined in the board. In a preferred embodiment, the VCO portion occupies one side of the module while an integrated circuit chip and a loop filter occupy an opposite side of the module.

A standard-size VCO/PLL module available today measures about 20.3 mm×14.7 mm×3.4 mm. The size of today's standard VCO/PLL modules, and underlying printed circuit boards, however, has proven to be too large for some of the next generation of electronic products such as, for example, the next generation infrastructure wireless base stations.
There thus remains a need for a VCO/PLL module, and underlying printed circuit board, which meets the needs and reduced size requirements of the next generation wireless infrastructure base stations. This invention meets these needs.


A caching system for a 3D modeling system. Intermediate channel results, created during the generation of a representation of an object, are cached. The caching increases the speed of system. In particular, the representation of the object is generated in multiple channels, each channel representing some portion of that representation. Intermediate channel results are generated in each channel by elements in that object's list of modifiers. Depending on for how long these intermediate channel results are valid, the intermediate channel results may or may not be cached. For example, if it is determined that one set of intermediate channel results will be valid for a predetermined period of time, while the next intermediate channel results in that channel will not be valid for a predetermined period of time, then the intermediate channel results are cached.

A. Field of the Invention
The invention relates generally to field of three dimensional modeling and animation. In particular, the invention relates to an improved three dimensional modeling and animation system having an object oriented architecture.
B. Related Art
Caching systems in computers allow a computer to store data that is likely to be reused in the near future. This generally improves the performance of a computer system. In 3D modeling systems, various caching schemes have been used. For example in some previous systems, images are cached as part of the normal data caching architecture of the computer system. For example, a portion of an image may be stored in a frame buffer or in a level 1 or level 2 cache. In other 3D modeling systems, basic caching techniques are used, such as keeping a portion of an image stored for redisplay when the user scrolls the image around the screen.
One problem with present caching systems is that they are not as high performance as is desired by users. Without optimized caching performance, a three dimensional modeling system can have severely limited performance. Therefore it is desirable to have an improved caching system for use in a three dimensional modeling system. In particular it is desirable to have an improved caching system for the display of the three dimensional model on the screen for the user.

Caching in a three dimensional modeling and animation system


The present invention provides structures and methods that utilize fuel reformation to assist in thermal management of a channel-less SOFC at the device cell and/or stack assembly level. At the device level, passive and/or active control of unreformed fuel, or a mixture of reformed and unreformed fuel, is used to inject fuel in a distributed manner along the anode chamber of the channel-less SOFC. The injected fuel can be controlled in its composition, pressure, velocities, and/or flow rates. Additionally, present invention provides thermal management across a plurality of fuel cells in a stack assembly by actively controlling fuel composition, pressure, velocities, and/or flow rates provided to fuel inlets of the fuel cells.

1. Field of the Invention
The present invention relates to structures for thermal management of planar solid oxide fuel cell systems, more particularly, those that enable internal reforming for thermal management at the device or cell level.
2. Description of the Related Art
The SOFC is widely considered the most desirable fuel cell for generating electricity from hydrocarbon fuels because it is highly efficient, and can at least partially internally reform hydrocarbon fuels. Solid Oxide Fuel Cells (SOFC) are reaching commercialization with several hundreds of residential stationary power units (about 1 kW) being tested in Europe and larger units (250 kW or above) being evaluated by various utility companies world wide. SOFC also are emerging as a possible power option for hybrid electrical vehicles and in auxiliary power units. Due to their high energy conversion efficiency (up to 40-60%), low toxic emissions, and flexibility in fuel choice (natural gas, diesel, gasoline, liquid petroleum, alcohol, coal gas, etc.), SOFC are being developed for the whole range of possible applications: stationary, transportation (or mobile), military, and portable.
Solid oxide fuel cells (SOFC) include a solid electrolyte medium separating the electrodes, typically a ceramic material such as yttria-stabilized zirconia (YSZ). The anode is usually a porous metal composite, such as Ni-cermet, and the cathode typically lanthanum-strontium manganese oxide (LSM). In SOFCs, hydrogen (or raw fuel) is converted to water at the anode while oxygen is converted into oxygen ions that migrate through the electrolyte ceramic to the anode. As the main current carriers are oxygen ions, which diffuse slowly at room temperature, operating temperatures ranging from about 800° C. to 1000° C. are typically used. These high temperatures require exotic and costly materials such as lanthanum chromite to be used for current collectors (interconnects).
FIG. 12 shows a conventional fuel cell assembly, which includes four basic elements: an anode, a cathode, an electrolyte, and an interconnect. The oxidant, usually air, is fed through a plurality of channels defined by the cathode and grooves in the interconnect to provide needed oxygen for the dominant reaction of hydrogen oxidation. In addition, the oxidant serves as a coolant when the fuel cell is hydrogen fed, and provides heat needed when the fuel cell assembly is methane fed (i.e. cells including endothermic internal methane reforming). In a manner complementary to the structure for providing oxidant to a cell, fuel is fed through a plurality of channels on the anode side of the cell, which are defined by the grooves formed in the interconnect and the anode. With such a structure, oxygen ions are conducted by the electrolyte and electrons are conducted by the interconnect during the process of hydrogen oxidation.
The electricity providing chemical reaction occurring at elevated temperatures in the SOFC is hydrogen oxidation (H2+0.5O2→H2O), which is exothermic (ΔH=−241.8 kJ/mol−H2) in nature, and thus heats the reaction sites. Left unchecked, the cumulative temperature within a cell/stack can quickly exceed maximum material design temperatures. In addition, the mass flow rates and partial pressures of the reactants as well as gas-phase temperatures vary along the direction of fuel flow causing temperature gradients. Large temperature gradients result in thermal stresses in the fuel cell, which can cause damage to the fuel cell's components. As such, temperatures must be managed to within a target range. Conventional methods of managing temperature include use of variable oxidant and fuel flow rates, heat exchangers within stack structures, and internal reforming.
Some level of heat transfer from the reaction sites to the fuel and oxidant gases occurs during normal operation of a SOFC. The amount of thermal energy in the gas is from a combination of gas-phase reactions as well as exchange (heat transfer) with solid-phase parts of the cell (anode, cathode, electrolyte, bipolar plates, etc.). With only the oxidation reaction predominant, and neglecting solid-gas heat transfer, the primary method of managing heat is through the heat capacity of the gas according to the general heat exchange relationship:Q=q/CpρΔT  (1)where Q=volumetric flow rate (m3/s), q=amount of heat transferred (kJ/s), Cp=specific heat of gas (kJ/kg−K), ρ=density of gas (kg/m3), and ΔT=temperature differential between gas inlet and gas outlet (° K). From equation (1), it can be seen that the volumetric flow rate of the gas is inversely proportional to the change in temperature. Thus, a greater flow rate leads to a lower change in gas temperature. In this way, stack temperature can be controlled.
In some cases, however, it would not be practical or cost effective to use fuel and/or air flow rates alone to control temperature. Thus, alternative methods of heat exchange and/or recovery are needed. However the alternative methods of heat exchange and/or recovery add cost, size and complexity to SOFC design.
Another approach currently being considered involves introducing a portion of unreformed fuel such as methane into the fuel cell channels with some amount of water to perform steam methane reforming, which is highly endothermic. This method can reduce the system complexity (no need for external reformers) as well as manage temperature within and throughout the stack. Mathematical modeling of distributed feed profiles has been described in the literature. For instance, Ayman M., Al-Qattan, Donald J. Chmielewski, "Distributed Feed Design for SOFC's with Internal Reforming", Journal of The Electrochemical Society, 151 (11) A1891-A1898 (2004), describes using mathematical modeling and simulation to analyze chemical and thermal gradients, predict thermal-chemical performance, and propose distributed feed concentrations. While the Ayman et al. publication describes the concept of distributed feed to manage thermal-chemical gradients, it does not evolve the distributed feed designs/results into potential physical embodiments. Furthermore, it does not define SOFC stack level thermal management concepts as described herein with respect to the present invention. (A stack is constructed of a plurality, usually more than three, stacked SOFC devices.)
Another conventional method for thermal management of a fuel cell described in PCT Application No. WO 03098728 to Foger et al. involves processing a fuel supply stream of hydrogen, steam, at least one carbon oxide, and optionally methane, using a methanator to produce a fuel cell supply stream comprising a controlled concentration of methane, and reforming within the fuel cell methane present in the fuel cell supply stream. The methanator adjusts in response to fluctuations in the temperature of the fuel cell such that the concentration of methane in the fuel cell supply stream is controlled in order to achieve a desired level of reforming of methane within the fuel cell. While the Foger et al. method and design provides temperature control of the planar SOFC stack via internal reforming, thermal management is of the complete stack without regard to individual devices, cells, or active area. Furthermore, temperature gradients in the cell/device can still exist along the fuel/oxidant flow direction and or along the direction of voltage build in the stack.
Thus, there remains a need in the art for more efficient, flexible and less complex structures and ways for managing fuel cell stack temperatures at the fuel cell or the fuel cell device level.

SOFC thermal management via direct injection


A capacitor for a semiconductor structure is formed having a substrate, a stack of a buffer layer and a layer of ferroelectric material, and a top electrode. The capacitor can also have a layer of polysilicon between the substrate and the buffer layer. A method for forming the same, through establishing a substrate, a buffer layer and a layer of ferroelectric material, defining and annealing the buffer layer and layer of ferroelectric material, and establishing a top electrode, is also disclosed.

The present invention is directed to a ferroelectric capacitor having a silicon/dielectric/metal structure.
Presently, silicon dioxide is used as the dielectric in the storage capacitor of dynamic random access memory (DRAM) cells. However, as densities increase to the 64 M-bit range and beyond, charge storage using a SiO.sub.2 capacitor requires a large amount of space (area) due to the low dielectric constant of SiO.sub.2, which is approximately 3.9. The large area required by these capacitors results in the capacitor being too large to be of practical use in the industry. As a result, the industry has been in search of a material to replace silicon dioxide as the dielectric in a capacitor. With a larger dielectric constant, assuming the separation between capacitor plates remains the same, the same capacitance is obtained using a smaller area.
One material that has been considered for possible use as the dielectric in a capacitor is a ferroelectric material, such as a compound comprising lead zirconate titanate ("PZT"). Ferroelectric materials are of interest because materials such as PZT have a high dielectric constant. In U.S. Pat. No. 4,853,893 to Eaton, Jr. and Parris, owned by Ramtron Corporation of Colorado Springs, Colo., there is a discussion of using PZT as a dielectric material for a DRAM memory cell capacitor. That citation calls for substituting PZT for SiO.sub.2. Col. 9, line 57 et seq. see also, U.S. Pat. No. 4,536,785 to Gibbons.
However, when a ferroelectric material is established on a silicon substrate, interdiffusion occurs between the ferroelectric material and the silicon substrate. As a result, a low dielectric constant layer is formed in series with the ferroelectric material causing the resulting structure (a stack) to appear as two capacitors in series, one with a low dielectric constant and one with a high dielectric constant (the ferroelectric material). This causes the effective dielectric constant of the entire stack to decrease two orders of magnitude. The two order decrease occurs because the existence of the low dielectric constant layer dominates the total capacitance of the entire stack. Accordingly, the result is a capacitor with an average capacitance rather than one with a very high capacitance as would be obtained when using a ferroelectric material without a low dielectric constant layer in series with it.
The use of a high dielectric constant stack comprising a buffer layer, a layer of ferroelectric material and a second buffer layer as the gate dielectric in a field effect transistor is the subject of an invention and companion patent application entitled Structure and Fabrication of High Transconductance MOS Field Effect Transistor Using A Buffer Layer/Ferroelectric/Buffer Layer Stack as the Gate Dielectric by the same inventors as this application, George Argos, Jr. and T. S. Kalkur (attorney docket no. RAM 342) and which is incorporated herein by reference.
The object of the present invention is to provide a capacitor and method of fabrication therefor which does not suffer from the serious drawbacks we have described.

Structure of high dielectric constant metal/dielectric/semiconductor capacitor for use as the storage capacitor in memory devices


A system and a method to avoid packet traffic congestion in a shared-memory switch core, while dramatically reducing the amount of shared memory in the switch core and the associated egress buffers, is disclosed. According to the invention, the virtual output queuing (VOQ) of all ingress adapters of a packet switch fabric are collapsed into its central switch core to allow an efficient flow control. The transmission of packets from an ingress buffer to the switch core is subject to a mechanism of request/acknowledgment. Therefore, a packet is transmitted from a virtual output queue to the shared-memory switch core only if the switch core can actually forward it to the corresponding egress buffer. A token based mechanism allows the switch core to determine the egress buffer's level of occupation. Therefore, since the switch core knows the states of the input and output adapters, it is able to optimize packet switching and to avoid packet congestion. Furthermore, since a packet is admitted in the switch core only if it can be transmitted to the corresponding egress buffer, the shared memory is reduced.

The explosive demand for bandwidth over all sorts of communications networks has driven the development of very high-speed switch fabric devices. Those devices have allowed the practical implementation of network nodes capable of handling aggregate data traffic in a large range of values i.e., with throughputs from a few gigabit (109) to multi-terabit (1012) per second. To carry out switching at network nodes, today's preferred solution is to employ, irrespective of the higher communications protocols actually in use to link the end-users, fixed-size packet (or cell) switching devices. These devices, which are said to be protocol agnostic, are considered to be simpler and more easily tunable for performances than other solutions especially, those handling variable-length packets. Thus, N×N switch fabrics, which can be viewed as black boxes with N inputs and N outputs, have been made capable of moving short fixed-size packets (typically 64-byte packets) from any incoming link to any outgoing link. Hence, communications protocol packets and frames need to be segmented in fixed-size packets while being routed at a network node. Although short fixed-size packet switches are thus often preferred, the segmentation and subsequent necessary reassembly (SAR) they assume have a cost. Switch fabrics that handle variable-size packets are thus also available. They are designed so that they do not require or limit the amount of SAR needed to route higher protocol frames.
Whichever type of packet switch is considered they have however in common the need of an efficient flow control mechanism which must attempt to prevent all forms of congestion. To this end, all modern packet switches use a scheme referred to as 'virtual output queuing' or VOQ. As sketched in FIG. 1, all ingress port adapters or IA's (100) to a switch core (110) are temporarily storing incoming packets (105) in a 'first come first served' or FCFS order, generally in the form of linked list of packets (120) however, sorted on a per destination basis and more generally on a per flow basis (125). Depending on the type of application considered, flows can have to be differentiated not only by their destinations but also according to priorities or 'class of service' (CoS) and possibly according to other traffic characteristics such as of being a multicast (MC) flow of packets that must be replicated to be forwarded to multiple destinations as opposed to unicast (UC) flows. Hence, flows are differentiated with flow-ID's which include destinations and possibly many more parameters especially, a CoS.
Organizing input queuing as a VOQ has the great advantage of preventing any form of 'head of line' or HoL blocking. HoL blocking is potentially encountered each time incoming traffic, on one input port, has a packet destined for a busy output port, and which cannot be admitted in the switch core, because flow control mechanism has determined it is better to do so e.g., to prevent an output queue (OQ) such as (130) from over filling. Hence, other packets waiting in line are also blocked since, even though they would be destined for an idle output port, they just cannot enter the switch core. To prevent this from ever occurring, IA's input queuing is organized as a VOQ (115). Incoming traffic on each input port i.e., in each IA, is sorted per port destination (125) and in general per class of service or flow-ID, so that if an output port is experiencing congestion, traffic for other ports, if any, can be selected instead thus, has not to wait in line.
This important scheme of switch fabrics which authorizes input queuing without its drawback i.e., HoL blocking, was first introduced by Y. Tamir and G. Frazier, "High performance multi-queue buffers for VLSI communication switches," in Proc. 15th Annu. Symp. Comput. Arch., June 1988, pp. 343-354. It is universally used in all kinds of switch fabrics that rely on input-queuing and is described, or simply assumed, in numerous publications dealing with this subject. As an example, a description of the use of VOQ and of its advantages can be found in "The iSLIP Scheduling Algorithm for Input-Queued Switches" by Nick McKeown, IEEE/ACM TRANSACTIONS ON NETWORKING, VOL. 7, NO. 2, April 1999.
The implementation of a packet switching function brings a difficult challenge which is the overall control of all the flows of data entering and leaving it. Whichever method is adopted for flow control, this always assumes that packets can be temporarily held at various stages of the switching function so as to handle flows on a priority basis thus supporting QoS (Quality of Service) and preventing switch to get congested. VOQ scheme fits well with this, allowing packets to be preferably held in input queues i.e., in IA's (100), before entering the switch core (110) while not introducing any blocking of higher priority flows.
As an example of this, FIG. 1 shows a shared-memory switch core (112) equipped with port OQ's (135) whose filling is monitored so as incoming packets can be held in VOQ's to prevent output congestion to occur. To prevent OQ's from ever overflowing, packets are no longer admitted when an output congestion is detected. Congestion occurs because too much traffic, destined for one output port or a set of output ports, is entering the switch core. As an elementary example of this one may consider two input ports each receiving 75% of their full traffic destined for a same given output port. This latter can only drain 100% of the corresponding traffic (ports IN and OUT typically, have identical speed) thus, the traffic in excess (50%) must be stored in the shared-memory and starts to build-up. If congestion lasts, and if nothing is done, the shared-memory fills up and the related OQ (130) soon overflows. Therefore, all OQ's are watched so as, if they tend to fill up, a feedback mechanism (140) prevents packets for a congested switch core output from leaving the corresponding VOQ's of IA's. This is easily achieved since VOQ's, in each ingress IA, are organized per destination as discussed above. Obviously, this is done on a priority basis i.e., lower priority packets are held first (although, for a sake of clarity, this is not shown in FIG. 1, VOQ's are organized per priority too) according to a series of thresholds (145) associated to the set of OQ's (135).
This scheme works well as long as the time to feed the information back to the source of traffic i.e., the VOQ's of IA's (100), is short when expressed in packet-times. However, packet-time reduces dramatically in the most recent implementation of switch fabrics where the demand for performance is such that aggregate throughput must be expressed in tera (1012) bits per second. As an example, packet-time can be as low as 8 ns (nanoseconds i.e.: 10−9 sec.) for 64-byte packets received on OC-768 or 40 Gbps (109 bps) switch port having a 1.6 speedup factor thus, actually operating at 64 Gbps. As a consequence, round trip time (RTT) of the flow control information is far from being negligible as this used to be the case with lower speed ports. As an example of a worst case traffic scenario, all input ports of a 64-port switch may have to forward packets to the same output port eventually creating a hot spot. It will take RTT time to detect and block the incoming traffic in all VOQ's involved. If RTT is e.g.: 16 packet-times then, 64×16=1024 packets may have to accumulate for the same output in the switch core. A RTT of 16 packet-times corresponds to the case where, for practical considerations and mainly because of packaging constraints, distribution of power, reliability and maintainability of a large system, port adapters cannot be located in the same shelf and have to interface with the switch core ports through cables. Then, if cables (150) are 10 meter long, because light is traveling at 5 nanoseconds per meter, it takes 100 nanoseconds or about 12 8-ns packet-times to go twice through the cables. Then, adding the internal processing time of the electronic boards, including the multi-Gbps serializer/deserializer (SERDES), this may easily add up to the 16 packet-times used in the above example.
Hence, when the performance of a large switching equipment approaches or crosses the 1 Tbps level, typically with 40 Gbps (OC-768) ports, RTT expressed in packet-time is becoming too high to continue to use a standard or back-pressure flow control mechanism such as the ones briefly discussed in FIG. 1. Because this type of flow control assumes that all IA's, independently, keep forwarding traffic to the switch core, and relies on the feedback (140) of flow control information to stop sending if a congestion is detected clearly, the reaction time becomes too high. When a congestion is detected, by the time it is reported to the sources, the situation may have dramatically worsen up to a point where it is no longer containable forcing to discard packets especially, if for an extended period of time, the traffic is biased to a single or a few output ports (hot spot).

System and method for collapsing VOQ's of a packet switch fabric

International Business Machines Corporation


In a fuel cell stack, coolant supply passages are provided on both sides in the width direction of a coolant flow field. At an inlet of the coolant flow field, a substantially triangular inlet buffer is provided. A recess protruding inward of the substantially triangular shape is provided adjacent to a vertex of the inlet buffer protruding in a horizontal direction.

1. Field of the Invention
The present invention relates to a fuel cell stack formed by stacking a plurality of fuel cells together. Each of the fuel cells is formed by stacking a membrane electrode assembly and separators together. The membrane electrode assembly includes a pair of electrodes and an electrolyte membrane interposed between the electrodes.
2. Description of the Related Art
For example, a solid polymer electrolyte fuel cell employs a solid polymer electrolyte membrane. The electrolyte membrane is a polymer ion exchange membrane. In the fuel cell, the electrolyte membrane is interposed between an anode and a cathode to form a membrane electrode assembly (MEA). The membrane electrode assembly and a pair of separators sandwiching the membrane electrode assembly make up a power generation cell (unit cell) for generating electricity. In use, typically, several tens to several hundreds of the power generation cells are stacked together to form a fuel cell stack, e.g., mounted in a vehicle.
In the fuel cell, a fuel gas flow field is formed in a surface of one separator facing the anode for supplying a fuel gas to the anode, and an oxygen-containing gas flow field is formed in a surface of the other separator facing the cathode for supplying an oxygen-containing gas to the cathode. Further, for every power generation cell or for every a predetermined number of power generation cells, one coolant flow field is formed between the adjacent separators, for supplying a coolant within electrode areas along surfaces of the separators.
Further, mostly, the fuel cell of this type adopts so called internal manifold structure. Specifically, a fuel gas supply passage and a fuel gas discharge passage, an oxygen-containing gas supply passage and an oxygen-containing gas discharge passage, and a coolant supply passage and a coolant discharge passage are formed in the fuel cell for allowing the fuel gas, the oxygen-containing gas, and the coolant to flow through the power generation cells in the stacking direction.
For example, a fuel cell stack disclosed in International Publication No. WO 2010/082589 includes power generation units each formed by stacking an electrolyte electrode assembly and metal separators. The electrolyte electrode assembly includes a pair of electrodes and an electrolyte interposed between the electrodes. Each of the metal separators has rectangular surfaces. The metal separator has a wavy gas flow field on its surface facing the electrode for supplying the fuel gas or the oxygen-containing gas as a reactant gas along the electrode. The power generation units are stacked together such that a coolant flow field, which corresponds to the back surface shape of the wavy gas flow field, is formed between the adjacent power generation units.
Further, a reactant gas supply passage and a reactant gas discharge passage as passages of the reactant gas extend respectively through two opposite sides of the metal separators in the stacking direction for allowing the reactant gas to flow through the reactant gas supply passage and the reactant gas discharge passage. A pair of coolant supply passages and a pair of coolant discharge passages as passages of the coolant extend through the other two opposite sides of the metal separators in the stacking direction, at least adjacent to the reactant gas supply passage or the reactant gas discharge passage, for allowing the coolant to flow through the coolant supply passages and the coolant discharge passages. The pair of coolant supply passages are arranged on the respective sides, while the pair of coolant discharge passages are also arranged on the respective sides.
Since the pair of coolant supply passages are provided separately on the two opposite sides and the pair of coolant discharge passages are also provided separately on the two opposite sides, it is possible to supply the coolant uniformly and reliably to the entire coolant flow field.


An active control system for rolling behaviors of high-speed trains includes a sensor, a controller and an output device. The output device includes a power unit, an output unit and a casing. The power unit and the output unit are arranged inside the casing. The active control system applies active control torque to the shaking, rolling and nodding of the train body so as to control the train.

High-speed trains have high running speed and complex dynamic behaviors. During the operation process, the trains may suffer from dynamic effects caused by track irregularities, air pressure differences generated when trains pass each other and other external factors such as wind, rain and snow. The dynamic behavior of the high-speed train generally involves a complex combination of translation (floating, yawing and stretching), swinging motion (nodding, shaking and rolling) of vehicle body and coupled vibration and motion thereof instead of merely a single motion mode. Therefore, it is of great theoretical and practical significance to develop a system suitable for the complex dynamic behavior control of high-speed trains.
Currently, the vibration and other unfavorable dynamic behaviors of high-speed trains are commonly controlled by using a suspension system. However, the existing suspension systems can work only in the vertical and lateral directions, and their output directions are also limited to the vertical and lateral directions, so that the suspension system cannot fully control the dynamic behavior of the high-speed trains, failing to sufficiently suppress the unfavorable dynamic responses.
During the actual operation process, the dynamic responses of trains will bring rotational motions, such as shaking, rolling and nodding. Moreover, these rotational motions cannot be effectively controlled by the linear force provided by the existing suspension systems. Therefore, the control effect of the existing suspension system on the trains is still limited, and the unfavorable dynamic responses of the trains cannot be fully suppressed.
In view of the increased speed of high-speed trains and requirements for riding comfort, the problems raised by the dynamic behaviors of trains, especially those involving rotational motion, generated from the complex effects during high-speed operation, will become more prominent. Therefore, it is of great theoretical and practical significance to develop a control system, which can directly output the control torque, to overcome the defects in the existing suspension technology, alleviating the unstable motion behaviors of the vehicle body when exposed to dynamic disturbance and the damages to the vehicle body and improving the dynamic stability, riding comfort and service life of the train.

Active control system for rolling behaviors of high-speed trains


The present disclosure involves computer-implemented methods, software, and systems for managing a transition between business process models. A computer-implemented method includes in parallel with a first business process model, instantiating, using at least one hardware processor, a second business process model, instantiating a temporary exit process step of a set of temporary exit process steps associated with the first business process model and a temporary entry process step of a set of temporary entry process steps associated with the second business process model, coupling an exit transition rule of a set of exit transition rules associated with the first business process model to the first business process model, and activating the exit transition rule after activating the second business process model.

Business processes defined by business process models in modern enterprise resource planning (ERP) systems typically define several process steps. Many business processes have evolved from single-enterprise business processes into inter-connected and networked business processes involving numerous, geographically-distributed business entities. The execution of a complete business process model may take an extended period of time, include different manual activities, and involve more than one business entity. A business organization wishing to transition from an executing first business process model to a second business process model may face a situation where various process steps of the first business process model may have already executed and it would be impractical or impossible for the organization to immediately transition to the second business process model or to stop the first business process model.


In an optical current transformer in which the Faraday rotation of light in a waveguide (2) enclosing the current is measured, the waveguide (2) is designed as an integrated-optics single-mode waveguide embedded in a substrate (1).. Further elements of the measuring device, such as polarizers (13), mirrors (11) and Y couplers (12, 14), may likewise advantageously be integrated into the substrate (1).. The integration leads to a sensor element (SE) which can be produced in a simple manner and is to a large extent insensitive to environmental influences such as temperature fluctuations and vibrations.

1. Field of the Invention
The present invention relates to the field of current measurement technology. It concerns an optical current transformer which makes use of the Faraday effect for the purpose of measuring a current, comprising
(a) a sensor element having an optical entrance for coupling in light and at least one optical exit for coupling out the light; PA1 (b) within the sensor element, an annular waveguide which encloses the current to be measured and is optically connected to the optical entrance and the at least one optical exit; and PA1 (c) means for measuring the magneto-optical rotation of the plane of polarization of the light in the waveguide. PA1 (d) the sensor element comprises a flat substrate with a continuous opening, situated at the center, for the current to be measured; PA1 (e) the waveguide is designed as an integrated-optics single-mode waveguide embedded in the substrate; and PA1 (f) the waveguide encloses the opening in at least one winding. PA1 (a) the substrate consists of a glass; and PA1 (b) the waveguide has been generated by exchange of ions in the glass.
Such a current transformer is known, for example, from DE-A1-3,116,149.
2. Discussion of Background
Optical current transformers which make use of the Faraday effect in a suitable material, especially a glass fiber, for the purpose of measuring the current, are known from a multiplicity of publications. By way of representative examples, reference is made in this connection to the following publications:
"Magnetooptical current transformer. 1: Principles", A. Papp et al., Appl. Optics 19 (1980), pp. 3729-3734; PA0 "Magnetooptical current transformer. 2: Components", H. Aulich et al., Appl. Optics 19 (1980), pp. 3735-3740; PA0 "Magnetooptical current transformer. 3: Measurement", H. Harms et al., Appl. Optics 19 (1980), pp. 3741-3745; and PA0 "Magneto-optical fiber sensors for electrical industry: analysis of performances", S. Donati et al., IEE Proc. 135 (1988), pp. 372-382.
In this connection, there are in the prior art various current transformer concepts which differ principally in the nature of the design of the sensor element or sensor head. In many cases, the sensor element consists of a glass fiber wound up in the manner of a coil (see the abovementioned publications). In other cases, the sensor is designed as a compact glass block which encloses the current path and in the interior diverts the light by means of mirror-coated corners around the current path (in this connection, see: "A new generation of current sensing", MOCT Technical Documentation Summary, Westinghouse ABB Power T+D Company, Electric Metering Systems, Raleigh, April 1989).
Various methods are employed for the evaluation of the measurement signal: one of these is the one-polarizer method, in which a single polarizer is disposed at the exit of the sensor for the analysis of the polarization (in this connection, see FIG. 1 of DE-A1-3,116,149). On the other hand, use is however also made of the polarimetric detection method, in which the polarization components in two mutually orthogonal directions are determined in a polarimetric detection unit (in this connection, see FIG. 3 of the above cited article by S. Donati et al.).
The earlier current sensors have the disadvantage either that they react sensitively (as in the case of wound glass fibers) to external disturbances of the waveguide, such as for example vibrations, change of temperature, mechanical pressure on the fiber, bending of the fiber, or that they are onerous and costly in production (as in the case of the mirror-coated glass block).


The present invention is a method for inspecting height, scanning the surface of a subject item having zones of different reflectance with incident light of a prescribed intensity, causing the reflected light from the surface to be imaged with means for detecting light spot positions, and detecting the height of said surface from the light spot position which was imaged, said method comprising: a step of scanning, in a second zone with low reflectance surrounding a first zone with high reflectance with a first intensity of incident light, which is low to the degree that said means for detecting light spot positions is not saturated even with said high reflectance; and a step of scanning, if it is detected that the quantity of light of the imaged light of said reflected light exceeds a prescribed threshold value, with an appropriate second intensity of incident light found from said intensity of incident light and said detected quantity of light at the time of the preceding scan.

1. Field of the Invention
The present invention relates to a method for inspecting height and a height inspection apparatus to carry out that method, especially a method and a height inspection device to carry out that method to inspect efficiently and with good precision the height of bumps formed on the surface of a semiconductor chip.
2. Description of the Related Art
A plurality of bump terminals, as input/output terminals, is arranged in a matrix on the surface of a semiconductor chip and the semiconductor chip is placed face down and bonded to a substrate. Such a semiconductor chip is called a flip chip and is used in multi-chip modules, etc.
These bump terminals are spherical terminals formed on electrodes formed on the surface of a semiconductor substrate; they include metal bumps formed with a plating method and solder bumps formed with a solder dip method.
A chip on which a plurality of bump terminals is formed is bonded face down on a substrate. In that case, each bump terminal must connect properly with the corresponding electrode on the substrate. Consequently, it is necessary that the form and height of the bumps be uniform. A height less than other bumps causes the connection with the electrode on the substrate to be no good. When the height is greater and the bump form large, the risk is of a short circuit with adjacent bumps in the bonding step.
Therefore, generally the height of bumps on the surface is inspected before a flip chip is bonded. General methods for inspecting height include the triangulation method wherein light is irradiated, the reflected light thereof is imaged on a split photodiode and PSD (Position Sensitive Detector), and the height detected. Consequently, the surface is scanned with laser beams and the height of each bump, according to the position of the reflected light, is inspected.
However, in the case of scanning spherical bumps with laser beams, the reflected light thereof causes a very irregular reflection in the vicinity of the bump and has a very high reflectance at the apex of the bump, while the reflectance on the surface outside the bump zone is comparatively constant. Because the reflectance of the surface varies greatly in this way, the intensity of the reflected light varies greatly when the intensity of the radiated light is constant. This is the reason why the quantity of reflected light deviates from the dynamic range of the PSD and photodiode; and the problem is that the height cannot be correctly measured.
Also, the method of measuring height directly from the position of the reflected light imaged on the position sensitive detector (PSD) with the triangulation method discussed above is effective for measuring the height of multiple bumps on a semiconductor chip surface. However, the direction of the reflected light is not constant according to the reflection position of the incident light on the bumps due to the curved shape of the bumps. As a result, errors occur in the height detected with the position sensitive element. Also, the focal displacement of the optical system also results in errors in the height detected. Moreover, the direction of those errors differs according to whether this was an anterior focal point or a posterior focal point. Furthermore, the position of the apex of the bump detected is displaced due to the displacement of the optical axis of the optical system to receive the reflected light; the detected height includes some error.
Furthermore, another problem is that an acousto-optic deflector is used for high speed scanning with laser beams of an LSI (large scale integration) chip having multiple bumps. The frequency variation signal supplied to the acousto-optic deflector is produced with a voltage oscillation circuit, for example. However, the problems include the problem of the astigmatism of this acousto-optic deflector, the problem of a dynamic variation of the astigmatism according to the distorted output characteristics of the voltage controlled oscillator, and the problem of the tolerance of the optical system. Because of these problems, it is very difficult to effect scanning of the measured object at a uniform speed and with zero astigmatism.
These problems are all problems brought about in the case of detecting the height of multiple bumps on a LSI chip. The resolution of all these problems is necessary for accurate height inspection.

Method for inspecting height, and a height inspection apparatus to carry out the method


A semiconductor memory device includes first and second column selection signal lines, first bit lines being and second bit lines. The first bit lines are associated with the first column selection signal line. The second bit lines are associated with the second column lines. At least one of the first bit lines is positioned between two of the second bit lines.

This invention relates to a semiconductor memory device and a method for designing the same.
A recent semiconductor memory device such as a DRAM (Dynamic Random Access Memory) device has a reduced size so that its bit lines are arranged very close to each other in the semiconductor memory device. The very close arrangement of bit lines might cause interference between the bit lines.
JP_A 2001-167572 discloses a technique to reduce interference between signal lines close to each other by twisting the signal lines together, the contents of the JP_A 2001-167572 being incorporated herein by reference. However, twisting of bit lines causes a semiconductor memory device to be larger in size. Therefore, there is a need for another technique to reduce interference between bit lines close to each other.

Semiconductor memory device and method for designing the same


A method for intercommunication between a mobile terminal and a WiMAX base station comprises: connecting the mobile terminal with a WiMAX wireless data card via an interface (S102); obtaining configuration information of the WiMAX wireless data card, and fulfilling the logic connection between the mobile terminal and the WiMAX wireless data card according to the configuration information (S104); and using the WiMAX wireless data card to fulfill the intercommunication with the WiMAX base station (S106). A system and a mobile terminal are used to implement the method.

WiMAX is a wideband wireless metropolitan area network (WMAN) technology based on the 802.16 series standards of Institute for Electrical and Electronic Engineers (IEEE).
At present, the dual mode mobile phone of global system for mobile communications (GSM)/wireless fidelity (WiFi) based on IEEE 802.1b standard can realize seamless handover between the GSM network and wireless local area network (WLAN), and support unlicensed mobile access (UMA) technology. Users can make up the defect that the indoor signal of mobile terminal such as mobile phone is weak. When network of the mobile phone is busy or the signal is bad, the mobile phone user can perform voice communication through the WiFi network. In practical application, the handover between the two networks is realized through the voice over IP (VoIP) technology, and the expense using this technology is comparatively low and the technology can provide convenience for the mobile phone and wide frequency wireless phone. In addition, the use of the VoIP technology can also realize the functions of browsing web page, sending and receiving e-mail, short messages and multimedia messages and so on. As long as the mobile phone is moved to the areas covered by the wireless wideband, the user can make a free call worldwide by a network phone mode.
In the present network, there are some areas still not covered by the GSM/WiFi networks, or some with bad signals of the GSM/WiFi networks. Aiming at the above-mentioned situations, the mobile phone terminal can realize the communication through the WiMAX network. Therefore, how to realize the intercommunication between the GSM/WiFi dual mode mobile phone and the WiMAX base station is a problem needed to be solved at present.

Method and system for intercommunication between mobile terminal and WiMAX base station, and mobile terminal


The present invention provides a combined rock puller and land leveler implement for alternatively pulling rocks from the ground or leveling the ground, and for pulling rocks from the ground and leveling the ground in one pass of the implement. The combined rock puller and land leveler comprises a frame having three individually articulated sections, a hitch attached to the front section, a rock pulling hook mounted on the front section behind the hitch, a land leveling blade mounted on the second section and ground wheels on a third section, and hydraulic cylinders for repositioning the frame sections into a plurality of positions.

When removing large rocks and tree stumps from fields, particularly from farm fields, an individual usually employs a rock pulling implement. The rock pulling implement is positioned to engage the rock and is drawn out of the ground as the rock pulling implement is moved in a forwardly direction.
After removing the rock a hole is usually left in the surface of the ground which needs to be filled and leveled. To fill and level this hole the individual presently has to exchange the rock pulling implement for a land leveling implement. The land leveling implement is then positioned to engage the ground surface and is drawn across the ground and the hole thereby filling the hole and leveling the ground.
This technique is time consuming since equipment needs to be moved to and from the site, connected to the towing vehicle, and positioned for use. The need for two pieces of specialized equipment adds the additional problem of also making this technique expensive
A combined rock puller and land leveler implement is needed which alternatively pulls rocks from the ground or levels the ground, and which can both pull rocks from the ground and level the ground in one pass of the implement.


A system and method of creating a decorative panel enables the creation of a decorative panel through a unique arrangement of illuminating blocks. The blocks are arranged to form a decorative panel. The blocks have an internal channel that contains light emitting diodes and a central conductive member. The diodes can be adjusted and removed to achieve a desired pattern or message without removing any of the blocks. The diodes and central conductive member are easily accessible from one side of the blocks by sliding them in and out for interchanging diodes or maintenance of the wires. The decorative effect on the panel may be constantly regenerated by interchanging diodes from within individual blocks, without having to move the block. This is possible because the diodes are disposed internally in the blocks. Thus, the illuminating effect from within each block is manipulated to create a desired decorative effect.

The present invention describes a system and method of creating a decorative panel. The decorative panel is comprised of a plurality of illuminating blocks that are arranged to form an illuminating pattern or message. The blocks have an internal channel that contains light emitting diodes and wires. The illumination from the light emitting diodes is adjustable so as to form the pattern or message without having to remove a block from the decorative panel. The diodes and wires are easily accessible from the edge of the panel by accessing an end frame and sliding the series of frames in and to interchange diodes or maintenance the wires.
The inventor was familiar with the tile, glass/acrylic panel, and brick industry. The inventor knew that panels and blocks used to construct walls and floors were becoming increasingly popular to allow passage of light transmission. The inventor observed that there had been developments to light the tiles to show off their colors. One type of lighting noticed by the inventor included glass bulbs. However, the inventor quickly recognized that bulbs do not have a long life and removing such bulbs was expensive and time consuming. The inventor saw that another way to provide lighting for these tiles was to use fiber optics that are powered by a halogen light sources. However, fiber optic lighting systems are expensive to install and require a lot of energy to light the tiles.
Most importantly though, the inventor recognized that glass block construction units, formed into wall panels were never self-illuminated, but instead allowed light to pass through the glass block unit from a source exterior to the glass block unit. Natural daylighting, or an electrical source of light entered through one side of the glass block unit and exited through the other remaining side. Sometimes, to provide interesting special effects, neon lights, or other electric lighting devices were installed independently behind a wall of glass block. These prior art uses of electric lighting required their own form of support, so that in essence, the glass block wall and the electric lighting were abutted adjacent to each other, often in a crowded installation, whereby it was difficult to service the electric lighting adjacent to the glass block wall.
Also, the type of electric light chosen to illuminate the glass block wall, had its own inherent shape, for example, neon lights are usually provided in long narrow tubes of light, or fluorescent tubes in a somewhat larger format, but also long narrow tubes, and so these shapes of lighting fixtures were visible through the glass block wall, creating hot spots thus betraying their hybrid nature, as separate from the glass block and therefore not coordinating aesthetically with the rectilinear, cellular nature of a glass block wall.
The inventor performed some research to discover possible light sources. The inventor learned that LEDs provide a wide range of advantages over conventional light bulbs. First, they are long-lasting. LED devices last about 10 times as long as compact fluorescent bulbs, and as much as 133 times longer than typical incandescent bulbs. Because these devices last for years, maintenance and replacement costs are greatly reduced. Also, LEDs are durable, and hold up well to jarring and bumping. Since LEDs do not have a fragile filament, they are not damaged under circumstances in which an incandescent bulb would be broken. Additionally, LEDs run cool, which reduces heat build-up.
Consequently, the inventor decided that light emitting diodes (LED's) could be used as a light source for lighting glass or acrylic tiles and blocks. Through trial and error, the inventor learned that LEDs required a modification of the basic tile design to receive the LED's. LEDS could be installed underneath the tiles or to form a wall barrier, so once the tiles are in place and are grouted the LED tile assembly becomes permanent. Since the LED's have a life of a several years, the tiles would then have to be removed and the LED's replaced. The inventor recognized that replacement and reinstallation is a very time consuming and costly process that does not make using this type of installation of LED's a very viable option in lighting the glass and acrylic tiles and blocks especially since glass and acrylic are also expensive.
The inventor knew that the blocks could be bored out to form a central cavity. He decided to drill a channel through multiple blocks to support the LEDs and associated wires. After trial and error, the inventor saw that the light diffused through the blocks, as he had expected. However, the diodes and wiring were jumbled up and had no structure. The inventor then decided to provide a separate tubular casing for the diodes and wires. This not only facilitated access to the diodes, but provided additional structural integrity to the channel within the block.
Unfortunately, once the blocks were built to form an illuminated panel, accessing the diodes and wires was still problematic. The inventor decided to create a side door that pivoted to allow access to the channels in each block. The inventor also increased the width of the connectors between the frames that held the diodes and the grout/silicone between the blocks to restrict diffusion of the light.
A benefit of the present invention is that a decorative panel with interchangeable lighting is contained inside each block that forms a panel.
Another benefit is that decorative lighting patterns, messages, and other ornamental and advertising functions are generated by selective lighting of the blocks.
Another benefit is the facilitated access to the lighting from the side of the blocks.
Another benefit is that undesirable light transfusion between blocks is restricted by making the first and second end of the frame solid, creating a snug fit between the frame and the channel, and using grout and silicon between the blocks.
Another benefit is that an inexpensive, easy to manufacture decorative panel is created using a plurality of blocks with internal illumination
Color patterned walls and signs have been used for advertising and sending messages, yet none with the present characteristics of the present invention. See: U.S. Pat. No. 5,955,156; U.S. Pat. No. 6,929,382; and U.S. 2006/0197474.
For the foregoing reasons, there is a need for a system and method of creating a decorative panel that will allow highrise buildings to display illuminated designs that can be changed without the need of contacting cranes or having workers hang from the outside of the buildings to change or work on the designs.

System and method of creating a decorative panel