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Although a variety of designs exist for roof vents, historically, “ridge type” roof vents have not been widely used for tile roofs. This is rather easy to understand, since although such a design would reduce the number of roof penetrations necessary to achieve adequate ventilation, the cumbersome and weighty nature of roof tiles has not been generally conducive to incorporation of a ridge type vent system in the roof design. And, although a few designs have been proposed or actually used, in so far as is known to us, prior art ridge vent designs have not adequately addressed the problem of preventing ingress of wind blown water, as might occur during a thunderstorm or hurricane, for example. Thus, it would be desirable to provide a new ridge vent design that is resistant to entry of wind blown water, especially if such a design were provided in a structurally strong, low profile, artistically pleasing ridge top roof vent system suitable for tile roofs or the like. | {
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1. Field of the Invention
The present invention relates to the field of toilet drain valves, and more particularly to a flapper drain valve adjusting structure.
2. Description of Related Art
At present, a flapper is generally used for opening a drain valve installed in a water tank of a toilet, and the flapper has two swinging link rods installed on a side of the flapper and rotatably connected to a fixed rotating shaft, a chain connected to the top of the flapper, a hemispherical body downwardly protruded from the middle of the bottom of the flapper, and a rubber pad embedded around the hemispherical body. The flapper is generally dropped at the top of a water outlet of the drain valve, and the rubber pad abuts the periphery of the water outlet of the drain valve. When a user pulls a chain upwardly, the flapper swings upwardly by using the fixed rotating shaft as the center of the swing, so as to open a water outlet and allows the water in the water tank to flow out from the water outlet, and the hemispherical body has an air chamber formed therein for determining the falling speed after the chain is released, so as to achieve the effect of controlling the drainage quantity of water.
During the process of using a toilet, it is inevitable to have the issues of damaging the flapper and requiring a change of the flapper, but different models of flappers produced by different manufacturers vary, and flappers come with different sizes that cause the issues of incompatibility and inconvenient installation. With reference to FIG. 1 for a conventional flapper 100 developed by related manufacturers, the flapper body 1 is coupled to a first installation position 311 and a second installation position 312 of two swinging link rods 2, so that there are four methods available for the connection between the swinging link rod 2 and the flapper body 1. Specifically, a sideway movement adjusting plate 4 is installed between the first installation position 311 and the second installation position 312 for preventing the swinging link rod 2 from sliding freely as well as sliding the swinging link rod 2 between the first installation position 311 and the second installation position 312 for changing the installation position 31. In addition, a claw buckle is formed at the other end of each of the two swinging link rod 2 and provided for rotably fixing onto the fixed rotating shaft. From the description above, although the flapper structure can provide a wide applicability for the flapper, yet the requirements for the precision and structure are more stricter for the installation of the adjusting plate in actual manufacturing processes, thus causing the issues of failing to prevent the swinging link rod 2 from sliding freely and failing to adjust the installation position 31.
In view of the drawbacks of the prior art, the inventor of the present invention based on years of experience in the related industry to conduct extensive researches and experiments, and finally developed a flapper drain valve adjusting structure in accordance with the present invention to overcome the aforementioned drawbacks of the conventional flapper of a drain valve of a toilet. | {
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In recent years, the production amount of semiconductor devices has shown a steady increase, and a reduction in production cost thereof has become an important task. For bonding of semiconductor chips to a lead frame, there is a method of using, as an adhesive, an inorganic material such as gold-silicon eutectic material or the like. This method is expensive and may incur breakage of semiconductor chips caused by thermal stress; therefore, a method of using a die-attaching paste (a paste-like adhesive) obtained by dispersing a filler in an organic material or the like, has become a main stream.
Meanwhile, with respect to the reliability of semiconductor devices, solder cracking resistance is particularly important. A die-attaching paste capable of giving a semiconductor device having satisfactory solder cracking resistance needs to have a low modulus of elasticity for relaxation of the difference in linear expansion coefficient between semiconductor chips and lead frame.
In recent years, the requirement for solder cracking resistance has become strict; as solder has become lead-free, the reflow soldering conditions have been switched from 240° C. to 260° C.; in order to meet this temperature increase of 20° C., a lower elastic modulus has become necessary. For a lower elastic modulus, die-attaching pastes using a low-stress substance (e.g. a rubber) have heretofore been known; however, they are unable to satisfy the recent requirement for solder cracking resistance and an improved die-attaching paste is needed. | {
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The present disclosure relates to energy-absorbing apparatus, and in particular, to devices for dissipating energy associated with external impact forces. More particularly, the present disclosure relates to an energy-dissipation system included in a juvenile product such as a child-restraint system.
When exposed to an external impact force, a juvenile vehicle seat at rest on a seat in a car or truck will accelerate as it moves to a new location in the passenger compartment of a car or truck. A child seated in such a moving juvenile vehicle seat will also accelerate as the juvenile vehicle seat moves in the passenger compartment.
A g-load is a measurement of an object's acceleration measured in gs. The g is a non-SI unit equal to the nominal acceleration due to gravity on earth at sea level. A short-term acceleration experienced by a child seated in a juvenile vehicle seat (or any other juvenile seat) that moves suddenly is called a shock and is measured in gs. | {
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This invention relates to devices for producing reinforced-concrete pipes, mostly large-diameter ones (4 to 8 m) made use of in constructing sectional pipelines of diverse applications.
Pipe producing plants made according to the present invention can find application as the component of a casting yard on the object being erected immediately at the sites of constructing sectional pipelines of water-accumulating hydroelectric power stations, as well as land reclamation, water-management and some other structures, the amount of which is growing incessantly.
It is common and widespread practice to use the centrifuging method of making reinforced-concrete pipes, wherein concrete mix filled by the feeder into the interior of a rotating mould, is placed uniformly along the inner perimeter of the cylinder-shaped mould due to a centrifugal force thus developed, then gets compacted to assume a preset shape of pipe. However, the centrifuging method of pipe production is actually practicable for pipes not in excess of 1 m in diameter.
Practical experience in producing reinforced-concrete pipes having 4 to 8 m in diameter is now far from being extensive. Thus, one prior-art plant for producing 8 m diameter pipes is known to comprise the following self-contained devices: a stationary form (or mould) with a concrete mix placer device, a station at which reinforcement (rod or wire) is wound onto the moulded pipe, and a station at which a protective coating is applied to the pipe surface.
A disadvantage of the above-mentioned solution (which is an advanced one as a whole) resides in that the production flow-sheet includes such operations as removal of a semi-finished pipe from one of the devices of the production line, its transferring to other devices and accurate setting of said pipe thereon, which adds to the labour consumption of the pipe production process and involves the use of a complicated specialized equipment and highly skilled personnel to attend said equipment.
Furthermore, descending of a heavy-weight workpiece onto a technological production element results in dynamic loads which accelerate wear of the production equipment and impose some additional requirements thereupon. Moreover, the process of filling the mould (having a perimeter of about 25 m) with concrete mix is a very complicated one, while especially sophisticated is the smoothing of the pipe end face to attain a degree of flatness required for a reliable butt-joining of the pipes. | {
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Various forms of lighting fixtures and decorative displays are known. For example, lamps, wall sconces and pendant mounted ceiling lights, lighted signs, and various other devices have been provided. Continued improvement in the field and new product alternatives are sought. | {
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The present invention relates generally to the technology of induction heating and more particularly to the use of induction heating for case-hardening of machine components such as gears.
Machine components such as gears, splined shafts and sprockets are frequently subjected to high torque loads, frictional wear and impact loading. The gears in a power transmission, for example, will encounter each of these forces during normal operation. In the typical gear production facility, the machining of gear teeth is followed by heat treatment to harden them. Heat-treating gears can involve many different types of operations, all of which have the common purpose or singular objective of producing a microstructure with certain optimum properties. The hardening process, however, often distorts the gear teeth resulting in reduced and variable quality.
In order to avoid these problems associated with conventional heat-treating and to improve the ability of the machine component (gear) to withstand the aforementioned loads and wear forces, the base metal is given a hardened outer case by selective hardening. In this manner, it is only the outer surface which is altered and the base metal retains its desirable properties such as strength and ductility.
One technique for the selective hardening of this outer case on such machine components as gears is to induction-harden the gear teeth individually. Another hardening technique which is also selective is a process referred to as selective carburizing. Single-tooth induction hardening is performed with a shaped intensifier that oscillates back and forth in the gear tooth space. This is usually done with the gear submerged in the quench. The process is relatively slow because only one gear tooth is processed at a time. Selective carburizing is most widely used and the process involves covering the surfaces to be protected against carburizing with a material that prevents the passage of active carbon during the furnace operation. The most widely used method to stop carbon activity is copper plating. A gear is copper plated on all surfaces except the teeth, then carburized. The part is then copper stripped, finish machined, re-copper plated all over, furnace-hardened, and quenched.
The difficulties and expense of the carburizing process have prompted companies to consider alternative techniques such as induction heating for selective case hardening, but to do so on a larger scale as opposed to the single-tooth method. U.S. Pat. No. 4,675,488, which issued Jun. 23, 1987, to Mucha et al., discloses a variation on the single-tooth process described above, wherein the process involves inductively heating and then quench-hardening a few teeth at a time while the rest of the teeth are cooled for the purpose of preventing drawback of previously hardened teeth (column 1, lines 55-65). While all of the teeth are ultimately induction-hardened, the inductors are extremely complex and expensive. The Mucha et al. patent also mentions the attempt by others for several years to devise a means for induction hardening the outer peripheral surfaces of gears by using an encircling inductor so that the gears can be treated by the inductor and then quench-hardened immediately thereafter in order to create the desired case hardening on the outer surface of the gear. The solution suggested by the Mucha et al. patent is to provide two induction heating coils with the workpiece located concentric in the first induction heating coil. The first coil is energized with tile first alternating frequency current for a fixed period of time. Once deenergized, the workpiece experiences a time delay period and thereafter the first induction heating coil is reenergized with a second alternating frequency for another fixed period of time, though substantially less than the first period of time with the first alternating frequency. At the end of this second period of time, the workpiece is immediately transferred into the second induction heating coil in a concentric manner and experiences a second time delay. Following this step, the second induction heating coil is energized with a radio frequency current for a third time period and immediately quenching the outer surfaces by quenching liquid sprayed against the surfaces while the workpiece is in the second induction heating coil.
Several years ago, a dual-frequency arrangement for induction heating was described wherein a low-frequency current would be used for preheating the gear teeth and then a high-frequency (radio frequency) current could be used for final heating prior to quench hardening. This dual-frequency arrangement is employed to some extent by the Mucha et al. patent which is described above. This dual-frequency concept was also described by the present inventors in their article entitled "Induction Gear Hardening by the Dual Frequency Method" which appeared in Heat Treating magazine, Volume 19, No. 6, published in June, 1987. As they explain in their article, the principle of dual-frequency heating employs both high- and low-frequency heat sources. The gear is first heated with a relatively low-frequency source (3-10 kHz), providing the energy required to preheat the mass of the gear teeth. This step is followed immediately by heating with a high-frequency source which will range from 100-300 kHz depending on the gear size and diametral pitch. The high-frequency source will rapidly final heat the entire tooth contour surface to a hardening temperature. The gear is then quenched to a desired hardness and tempered.
Dual-frequency heating is the fastest known way of heating a gear. Heating times range from 0.14 to 2.0 seconds. This compares, for example, with 4-30 minutes required for a laser to scan a gear, tooth by tooth. In dual-frequency heating, the spinning workpiece is preheated while riding on a spindle centering fixture. Then a quick "pulse" achieves optimum final heat. Next the piece indexes into a water-based quench, for a total process time of approximately 15 to 30 seconds. Dual frequency is unique among gear-hardening methods in that it allows competing specifications to coexist. That is, for a given case depth requirement and distortion limitation, with conventional hardening methods one requirement tends to consume the other. Because dual-frequency hardening puts only the necessary amount of heat into the part (1/2 to 1/10 of the energy used in conventional induction), case depth requirements and gear geometry specifications can both be met, precisely.
With any induction heating process whether dual- or single-frequency, and regardless of the type of part and its material, the part characteristics dictate the optimum design of both the induction heating coil or coils and the most appropriate machine settings. Only with the properly designed coil and the appropriate machine setting is it possible to achieve the contour and case hardening specifications deemed to be the most appropriate from the standpoint of wear and load resistance while still retaining overall part strength, material ductility and part specifications. A gear which is too brittle will fail prematurely, often by a tooth cracking or breaking of the gear blank body.
Other patents which are known to exist that relate generally to induction hardening include the following:
______________________________________ U.S. Pat. No. Patentee Dated Issued ______________________________________ 4,749,834 Mucha et al. Jun. 7, 1988 4,757,170 Mucha et al. Jul. 12, 1988 4,785,147 Mucha et al. Nov. 15, 1988 4,855,551 Mucha et al. Aug. 8, 1989 4,855,556 Mucha et al. Aug. 8, 1989 ______________________________________
U.S. Pat. No. 4,749,834 discloses a method of hardening the radially, outwardly facing surfaces of a generally circular, toothed workpiece adapted to rotate about a central axis generally concentric with the outwardly facing surfaces whereby the extremities of the surfaces define an outer circle by the tips of the teeth of the workpiece. This workpiece is typically a gear and as illustrated in the various drawings is a gear of uniform tooth configuration.
U.S. Pat. No. 4,757,170 discloses a method and apparatus for progressively hardening an elongated workpiece having an outer generally cylindrical surface concentric with the central axis including the concept of providing closely spaced first and second induction heating coils each having workpiece receiving openings generally concentric with the axis of the workpiece. While this is a scanning type of system noting the rack and pinion drive of FIG. 1, it is also to be noted that the illustrated workpiece is a gear having uniform teeth.
U.S. Pat. No. 4,785,147 discloses an apparatus for hardening the outwardly facing teeth surfaces of a gear and is a continuation of a prior application which is now U.S. Pat. No. 4,749,834 and as such the disclosure and relevance is believed to be the same.
U.S. Pat. No. 4,855,551 discloses a method and apparatus for hardening the outwardly facing teeth surfaces of a gear. This patent is a continuation of a prior case which is now U.S. Pat. No. 4,785,147 and thus would have a description comparable to that prior listed patent.
U.S. Pat. No. 4,855,556 discloses a method and apparatus for progressively hardening an elongated workpiece having an outer generally cylindrical surface concentric with the central axis. This patent is a continuation of prior patent U.S. Pat. No. 4,757,170 and thus the disclosure would correspond with the disclosure of that earlier case.
It is believed that each of these foregoing five references do not relate in any way to induction hardening of gear teeth with a non-uniform geometry, namely one where the mass of each tooth varies from the heel to toe. Consequently, these five references are believed to have very limited, if any, relevancy to the present invention.
Traditionally, a fixed coil design has been used for a wide range of different parts and machine settings were made on a "best guess" basis by the induction machine operator. By fixing the coil, one variable is eliminated and the operator attempts to zero in on an acceptable final part by trial and error procedures. The more experienced the operator, hopefully the greater the number and variety of parts he will have experienced and to the extent that he is able to draw on that experience, he may be able to come close to an acceptable part, but only after repeated attempts.
Since this entire approach is not scientific, the best one can hope for is to reach an acceptable part but not an optimum part. This problem is magnified when applying induction heating to irregularly shaped objects such as gears. Heretofore, there has been no attempt to try and derive a set of formulae to precisely determine the most optimal coil specifications and induction machine settings for a given part and which is repeatable, part after part, regardless of the size, shape, material or other characteristics. Instead, gross parameters are selected for the coil based on general part size and then machine settings manipulated until the combination of variables comes close to something that can be accepted.
In order to avoid the uncertainty in coil specifications and machine settings and to enable induction hardening in a precise and optimum manner regardless of the type of machine component part or part geometry and features, the present inventors conceived the invention which is disclosed and claimed in U.S. Pat. No. 4,845,328 which patent is expressly incorporated herein by reference for the entirety of its disclosure. U.S. Pat. No. 4,845,328 discloses a machine structure and a method of induction hardening using a series of formulae for establishing coil specifications and machine settings which formulae are based on the component part size and features. This process of scientifically calculating the specifications for a unique coil and the machine variables (settings) based on individual part characteristics enables predictable and uniform results for the induction hardening of the part in an orderly and repeatable fashion.
Previously, any calculating which may have been done was rudimentary at best, based only on surface area and depth of penetration. The series of formulae of U.S. Pat. No. 4,845,328 allow the coil and machine variables to be set scientifically rather than by guesswork and the needless trial and error attempts are eliminated while at the same time improving part quality from merely an acceptable or tolerable level to an optimum level.
More specifically the U.S. Pat. No. 4,845,328 patent focuses on formulae and solutions for the induction hardening of parallel axis gearing. With constant tooth sizes for a given application, the formulae produce solutions for complete heating parameters. Other types or shapes of gears such as cross-axis, intersecting-axis and nonintersecting-axis (hypoid) gears do not have constant tooth sizes and therefore, do not follow the formulae.
In the prior patent of the present inventors the mathematical algorithm uses gear parameters such as diametral pitch. The process also relies on the size uniformity of each tooth from heel to toe. The positioning of the workpiece within the induction coils and the uniformity of the heating pattern across and through the workpiece from the inside diameter to the outside diameter reflects the fact of tooth size uniformity. While the induction hardening of parallel axis gearing has been quite successful with this prior invention and the method and machine of the U.S. Pat. No. 4,845,328, cross-axis, intersecting-axis and nonintersecting-axis gearing were discovered to create a unique situation due to the changing (increasing) mass of the gear teeth from toe to heel. As one example, hypoid gears which are found in any rear or four wheel drive car or truck possess a non-uniform heel to toe tooth geometry. In addition to the spiral type curvature to the individual teeth, there is more mass to each tooth moving outwardly from the toe to the heel. The present inventors addressed the unique situation of hypoid gears (and related cross-axis, intersecting-axis and nonintersecting-axis gearing) in U.S. Pat. No. 5,124,517, issued Jun. 23, 1992 to Storm, et al.
It has also been discovered that certain production considerations as well as certain hypoid gear geometries might warrant a different induction coil design and a slightly different positioning of the coil relative to the gear. For example, when there is a smaller than normal face (or cone) angle to the gear, a conical induction coil centered over tile workpiece may be more suitable than a generally cylindrical induction coil set at an inclined angle. For larger gears and for large quantity production runs it might be preferred to have a coil with a fixed angle of incline as contrasted to a variable mechanical attachment for the coil which fixes the induction coil at a desired angle of incline relative to the tooth surface of the workpiece. Regardless of the specific coil design or geometry or positioning relative to the workpiece, the objective of the present invention is to configure the coil so that the magnetic coupling, and thus heat, is higher at the heel of the gear where the metal mass is greater than at the toe of the gear where the metal mass is smaller. | {
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This invention relates to photographic objectives and more particularly to objectives of standard or quasi-standard field angle.
Triplet objectives of the Tessar type, though widely having used in photographic devices tend to exhibit large longitudinal deviation from an ideal image field in the sagittal plane. At the same time, their astigmatism is quite large.
Various proposals for improving the aberrations of the Tessar type objectives have been made. One of these proposals, disclosed in U.S. Pat. No. 3,011,401 makes use of an additional lens element of bi-convex form positioned at the rear of the objective. With this Tessar type of objective system it is quite difficult to achieve a good compromise between the requirements of increasing the back focal length and of minimizing the various aberrations. Another proposed system is disclosed in Japanese Patent Application Laid-Open No.Sho 51-143326 where the additional lens element is in the form of a positive meniscus lens. | {
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This invention relates to sliding seal and cylinder liner compositions for adiabatic engines. Specifically, this invention relates to a stable ceramic composition having a surface with a low coefficient of friction and a high wear resistance at high operating temperatures and a method for producing this composition.
This invention arose under United States Government Contract No. DEN3-352 and the United States Government has a nonexclusive, nontransferable, irrevocable paid-up license to practice or have practiced for or on behalf of the United States this invention throughout the world.
There has been great interest in developing an uncooled, ceramic diesel engine since ten to thirty percent of the work output of an internal combustion engine is expended on the cooling system. Nearly adiabatic operation and recovery of exhaust heat in a turbocompounding system may increase the thermal efficiency of such an engine to 48%. Additional benefits may include multi-fuel capability, reduced noise, reduced white smoke emissions, lower compression ratio, and reduced maintenance. Further, such an engine may be lighter and easier to produce because of the elimination of the need for a cooling jacket. In comparison to the overall effort on ceramic diesel engine development, little work has been done in the important area of developing a sliding seal/cylinder liner system capable of performing adequately under harsh conditions.
This invention relates to providing promising ceramic materials for piston rings and cylinder walls in the abiabatic diesel engine. There has been some progress in development of ceramic pistons (or piston caps) and cylinder liners for adiabatic engines but most designs involve a piston cap in a crosshead engine using conventional chromium-plated cast iron rings and low-temperature lubrication, which offers a very low coefficient of friction (about 0.05) and low wear rates. However, in a radiatorless engine, the temperature of the metal is likely to become unacceptably hot. Also, this type of design is bulky, involving extra piston weight and high inertial forces to the connecting rod as well as on the joint between the piston and the ceramic piston cap.
On the other hand, a simpler design in which the entire cylinder is cermic-lined requires that the piston rings slide against the ceramic liner, which will be quite hot. There is an urgent need to find materials from which sliding seal rings can be manufactured which will exhibit low friction and low ring/liner wear while sliding against a ceramic cylinder liner at high velocity and high temperature.
The piston crown temperature must be raised to over 880.degree. C. in order to achieve significant energy savings in the adiabatic diesel. Thus the prime requirement of the cylinder liner/seal ring system is resistance to thermal shock and retention of strength to temperatures much higher than that which the top ring in a conventional diesel may experience. The liner/ring combination must exhibit acceptable wear rates not only at high temperatures, but also at high velocities of as much as 5-10 meters per second, and under conditions of exposure to combustion products and excess oxygen. Low friction is essential. The liner materials of interest have been silicon carbide, silicon nitride, and partially-stabilized zirconia. The silicon carbide, although it has been used for solid lifters and precombustion chambers in the heavy-duty diesel program, has a high thermal conductivity, which reduces its usefulness for piston crown and cylinder liner applications.
Silicon nitride has been the material of choice in most recent work, because of its low thermal conductivity, relatively high strength at temperatures to about 1100.degree. C., resistance to thermal shock, and relative ease of manufacturing complex shapes. However, in the push for higher temperatures still, the limits of silicon nitride are already being approached. Interest exists in using zirconia because it is strong even at 1500.degree. C. and has better insulating properties than silicon nitride.
Although there is little experimental data on friction and wear of ceramics under conditions that would be experienced by the sliding piston seal in an advanced diesel engine, the information that is available is fairly consistent in that the carbides are identified as outstanding sliding seal materials. In work done by Finkin, Calabrese, and Peterson, as noted in ASLE Preprint #72LC-7C-2 (1972), oscillatory pin-on-plate sliding experiments were performed with various ceramic/cermet couples in air at 316.degree.-982.degree. C. A nickel molybdenum (Ni-Mo) bonded titanium (TiC) carbide cermet, sliding on dense magnesia-stabilized zirconia, was identified as the most promising material couple. A poor second was the nickel-molybdenum (Ni-Mo) bonded titanium (TiC) sliding on itself. Zirconia sliding on itself suffered catastrophic wear. | {
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U.S. patent application Ser. No. 12/431,035, filed Apr. 28, 2009, is hereby incorporated herein by reference and discloses methods for monitoring the operability of a GPS receiver in order to determine, or verify, the validity of global positioning satellite signals being received by the receiver.
U.S. Pat. No. 7,305,928, issued Dec. 11, 2007, is hereby incorporated herein by reference and discloses vessel positioning systems that maneuver a marine vessel in such a way that the vessel maintains its global position and heading in accordance with a desired position and heading selected by the operator of the marine vessel.
U.S. Pat. No. 7,267,068, issued Sep. 11, 2007, is hereby incorporated herein by reference and discloses systems wherein a marine vessel is maneuvered by independently rotating first and second marine propulsion devices about their respective steering axes in response to commands received from a manually operable control device, such as a joystick. The marine propulsion devices are aligned with their thrust vectors intersecting a point on a centerline of the marine vessel and, when no rotational movement is commanded, at the center of gravity of the marine vessel.
U.S. Pat. No. 6,485,341, issued Nov. 26, 2002, is hereby incorporated herein by reference and discloses methods for controlling the average speed of a vehicle over a time period or distance length and includes selecting a desired average speed, measuring an actual speed, and maintaining a cumulative error determined as a function of the difference between the average speed and actual speed at the time over which the actual speed measurement was taken.
U.S. Pat. No. 6,273,771, issued Aug. 14, 2001, is hereby incorporated herein by reference and discloses control systems for a marine vessel that incorporate a marine propulsion system that can be attached to a marine vessel and connected in signal communication with a serial communication bus and controller.
GPS receivers are commonly utilized to calculate and provide a current global position of a marine vessel. The global position is communicated to a control system, which automatically controls operation of a propulsion system of the vessel based upon the global position. This allows the control system to, for example, maintain a desired global position of the vessel or maintain a heading and/or speed of travel of the vessel.
Those having ordinary skill in the art of GPS receivers and control systems for the marine vessels understand that from a plurality of GPS signals received from GPS satellites, a microprocessor in the GPS receiver is able to calculate and provide to the control system: the longitude and latitude where the GPS receiver is located, the speed over ground (SOG) and the course over ground (COG) of the GPS receiver (and by association the SOG and COG of the marine vessel in which the GPS receiver is located), and the number of and location of the GPS satellites in terms of, for example, relative distance and azimuth from the GPS receiver. In some cases the GPS receiver is also able to calculate and provide to the control system the horizontal dilution of precision (HDOP) of the plurality of GPS signals. HDOP is a standard GPS accuracy metric that is largely based upon the geometric position of the satellites being used by the GPS receiver. | {
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The present invention relates to fuel distribution systems for gas turbine engines.
Fuel distribution systems for gas turbine engines are called upon to distribute fuel from a common distributor or manifold to a plurality of fuel injectors or nozzles positioned at various locations in the engine combustor. The fuel distribution must be effected over a wide range of engine operating conditions from light-off to maximum power, which represents a considerable variation in fuel flow rates.
Furthermore, the fuel must be distributed as uniformly as practical to the fuel injectors so that generally uniform combustion occurs in the combustor without obtaining undesirable temperature differentials therein. The required degree of uniformity of flow distribution depends on particular engine designs and conventional evaluation factors. For example, individual injector flow rates deviating up to about twenty percent from the average flow rate of the plurality of injectors are considered acceptably or generally uniform for practical utilization.
In a typical engine configuration, the fuel injectors are arrayed in a vertical plane circumferentially about the periphery of an annular combustor. Consequently, the injectors are positioned at relatively different heights and thus have correspondingly different fluid heads associated with their positions. The fuel distribution system design therefore must also take into account the maximum fluid head existing between the uppermost and lowermost positioned injectors if acceptably uniform fuel distribution to all injectors is to be achieved. This is because without compensation for the maximum fluid head, fuel will flow primarily only through the lowest injector at low fuel flow rates, since it has the lowest fluid head loss.
The maximum fluid head represents a pressure loss which is constant from light-off power to maximum power. This fluid head pressure loss is added to the pressure losses associated with the various elements of the fuel distribution system from the fuel pump to the injector for obtaining a total pressure loss which is proportional to fuel flow rate. Since the maximum fluid head pressure loss is a constant, its relative effect compared to the total pressure is more pronounced at light-off power (low fuel flow rate) and typically negligible at maximum power (high fuel flow rate).
For example, for a gas turbine engine of about 1000 shp and including fuel injectors located in a vertical plane around a 13-inch diameter circle, the maximum fluid head pressure is about 0.4 p.s.i. Total pressure losses at light-off power are typically on the order of 10 psi and at maximum power on the order of 100 psi to 1000 psi. Accordingly, the effect of the maximum fluid head is negligible at the maximum power condition (e.g. 0.4 psi/100 psi=0.004) and fuel distribution will be uniform.
Each injector fuel line should thus incorporate sufficient pressure loss to overcome this maximum fluid head differential to ensure that the lowermost injector does not receive substantially more fuel than the uppermost injector. This problem is most pronounced at low fuel rates since this maximum fluid head differential then becomes significant relative to the fuel flow driving pressure developed by the fuel pump. Thus, it is necessary to design the fuel distribution system such that the pressure losses in the injector fuel line are sufficiently relatively high at low fuel flow rates to accommodate this differential fluid head consideration, and yet are not so great at high fuel flow rates as to require unduly high fuel pressurization to overcome the higher pressure losses. It is also important that the pressure loss in the plural injector fuel lines be substantially uniform with respect to each other over the entire engine operating range to avoid unacceptable fuel flow rate maldistribution and as low as possible for maximum fuel distribution efficiency.
Heretofore, these design considerations have been met through the utilization of rather complicated and relatively expensive flow dividing and fuel metering valves to achieve acceptably uniform fuel distribution throughout the engine operating range. Since one of these valves is incorporated in each injector fuel line and a typical gas turbine engine will utilize a plurality of fuel injectors, e.g., twelve or more, these valves represent a significant expense item particularly in the case of small gas turbine engines, i.e., less than 3000 horsepower. These valves, which may be of the mechanical or fluidic type, typically operate automatically in response to fuel pressure to impose the requisite variable impedances to fuel flow, i.e., pressure losses, in the injector fuel lines calculated to achieve acceptably uniform fuel distribution throughout the engine operating range.
Furthermore, the reliability of the flow dividing and fuel metering operations of these valves may be affected by any contaminants in the fuel. Thus, these valves typically require periodic servicing and in some instances replacement.
It is accordingly an object of the present invention to provide an improved fuel distribution system for a gas turbine engine.
Another object is to provide a fuel distribution system of the above character which avoid the need for a flow dividing and metering valve in each of the injector fuel lines.
Another object of the present invention is to provide a fuel distribution system of the above character wherein acceptably uniform fuel distribution is achieved over the entire range of engine operating conditions while reducing the energy or pressure loss in the individual injector fuel lines.
Another object is to provide a fuel distribution system of the above character wherein pressure loss in the injector fuel lines is generally equalized with respect to each other over the range of engine operating conditions from light-off to maximum power.
Another object is to provide a fuel distribution system of the above character which is relatively immune to being plugged by contaminants in the fuel.
Another object is to provide a fuel distribution system of the above character which is inexpensive to implement, efficient in operating and reliable over a long service life. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field
This disclosure is concerned generally with prosthetic devices and specifically with an artificial skeletal ligament.
2. Prior Art
A ligament is a tough band of tissue serving to connect the articular extremities of bones or to support an organ in place. Since skeletal ligaments flexibly stabilize joints, they must withstand considerable amounts of force. Frequently, the skeletal ligaments are subjected to enough force to be torn or otherwise damaged, thereby resulting in instability of the joint. This results in pain and possible damage to other tissues. Although some torn ligaments can be repaired by simply sewing the torn ends together, such repair is not always possible in cases of severe damage or disease. Further, surgical repair is not always predictable and requires a healing period of minimal stress before the ligament can be functionally useful.
The above circumstances have led to the development of a variety of artificial ligaments. Examples of such ligaments can be seen in U.S. Pat. No. 3,988,783 (Collateral Ligament) and U.S. Pat. No. 3,953,896 (Cruciate Ligament), both issued to Treace. Other examples of related prostheses include U.S. Pat. No. 3,973,277 (Bone Implant) to Semple et al, U.S. Pat. No. 3,805,300 (Tendon Prosthesis) to Tascon-Alonso et al, U.S. Pat. No. 3,613,120 (Tendon) to McFarland, U.S. Pat. No. 3,545,008 (Tendon) to Bader, and U.S. Pat. No. 3,842,441 (Tendon Implant) to Kaiser.
Although prosthetic ligaments have a variety of outward appearances, they commonly consist of a flexible longitudinal material having two end portions. The end portions are used to firmly attach the ligament to two adjoining bones such as, for example, the lower femur and the upper tibia. In use, the flexible central portion of the prosthetic ligament is subjected to repeated flexing, stress, and, in some cases, abrasion against bone edges. This can result in deterioration and possible rupture of the prosthesis. Although it has been disclosed that damage due to bone abrasion can be minimized or eliminated by passing the ligament through a flared stainless steel bushing-like device cemented into a bone opening (e.g. U.S. Pat. No. 3,953,896), such devices tend to serve as ligament guides rather than as means for assisting in ligament attachment. Further, the stainless steel bushings that have been disclosed are very hard and do not provide an energy sink for the stresses of a flexing ligament. Without some sort of an energy sink at the points where a flexing ligament contacts a solid body, the possibility of damage due to built up stresses within the flexing ligament is thought to be increased.
We have made a prosthetic ligament which offers advantages over existing ligaments by uniquely combining a means for enhancing ligament attachment within a bone with means for providing an energy sink to minimize the possibility of damage from repeated flexing and abrasion. Details of our findings are disclosed herein. | {
"pile_set_name": "USPTO Backgrounds"
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A method is known in which surround-channel sounds are caused to reach a sound receiving point by having them reflected by wall surfaces utilizing a phenomenon that a sound that is output from a speaker array in which plural speaker units arranged regularly exhibits beam-like directivity. For example, Patent document 1 discloses a technique of causing left and right surround-channel sounds emitted from a speaker array installed right in front of a sound receiving point to reach the sound receiving point by having reflected by wall surfaces. With this technique, virtual speakers are formed in directions of wall surfaces that are located on the left and right of a sound receiving point. | {
"pile_set_name": "USPTO Backgrounds"
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The use of amplification techniques in a procedure for detection of a target molecules that include target nucleic acid sequences is well known in the art. Typically, this procedure includes enzymatic amplification of target nucleic acid sequences and detection of the target molecules by gel electrophoresis followed by Southern blot procedures.
A number of solid phase capture assays have also been developed to simplify the procedures for detection of target molecules including nucleic acid sequences. In these procedures two ligands are typically incorporated within amplified target nucleic acid sequences. A first ligand is used to capture, on a solid matrix, the target molecules that include the amplified target nucleic acid sequences and a second ligand is used to detect the target molecules by the binding of a signal producing reagent to this second ligand.
Solid phase affinity capture assays, however, require an extended reaction time to capture a high proportion of target molecules in a reaction mixture (Sauvaigo et al., Nucleic Acid Research, 1990, Vol. 18, pp. 3175-3182). Furthermore, when capture is mediated by amplification primers incorporating a solid phase affinity ligand, the sensitivity of the assay may be adversely effected by competition between free primers and primers incorporated in the target nucleic acid sequences.
The use of chromatography as a separation and concentration procedure is well known in the art. It has been reported that whereas DNA molecules are chromatographically mobile on moistened paper they fail to migrate when solutions are applied to dry paper (Bendich et al., Arch. Biochem. Biophys., 1961, 94, 417-423). | {
"pile_set_name": "USPTO Backgrounds"
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The present invention relates generally to digital computer systems, and more specifically to memory management of computer systems which utilize garbage collection.
Modern symbolic computing systems usually use a memory management technique called garbage collection. This technique involves allocating memory for objects from available free memory as they are requested, and returning memory to the pool of available memory when the objects can no longer be accessed.
The garbage collector is a process which runs independently of the applications which allocate memory and create garbage. A copying garbage collector is a process which, generally, scans through all of the currently accessible memory objects, and copies those which are accessible to a special location to be saved. Once this is done, all memory objects not so copied are garbage and can be reclaimed.
A copying garbage collector begins its collection operation by dividing the virtual memory space of the computer system into three logical spaces; oldspace, scavenge space, and newspace. Oldspace contains all of the objects which are to be collected. Scavenge space contains all of the pointers to oldspace objects, other than pointers within oldspace. Newspace contains objects which can be guaranteed not to point to objects in oldspace.
The garbage collector executes a processing sequence, often called a scavenger, which proceeds through scavenge space from one end to the other. When pointers to objects in oldspace are encountered, the objects pointed to are copied from oldspace to scavenge space, at a position ahead of the scavenger. When an object is copied from oldspace to scavenge space a forwarding pointer is stored in the vacated position in oldspace so that if another pointer to the same object is processed, the scavenger can simply change the other pointer to the new object location. When the scavenger reaches the end of scavenge space, all oldspace objects which are accessible have been copied out of oldspace. At this point, all of oldspace may be reclaimed.
The garbage collectors on many present computer systems are known as stop and collect garbage collectors. This type of process, as the name implies, causes normal operation of the system to cease while the garbage collection process is run. This greatly simplifies the collection process because objects are not being modified and created while the garbage collector is operating. However, such a system has the drawback that no useful processing can be done while the garbage collector is in operation. For large virtual address spaces, the time spent garbage collecting can be quite long. For example, systems having 10 to 60 megabytes can typically spend more than an hour for the garbage collection process.
Numerous incremental garbage collection systems have been implemented. These are primarily found on systems having hardware dedicated to symbolic processing. In general, the garbage collectors operate in a time-sharing arrangement with the normal system processes. This type of garbage collection is more difficult to implement, because care must be taken to insure that there is no unwanted interaction between the garbage collector and the normal system processes.
Since the length of time spent garbage collecting is proportional to the size of the address space being collected, some current garbage collection systems utilize the concept of generations of memory objects to collect less than the entire virtual memory space. This concept is based on the observation that a high proportion of newly created objects become garbage quickly, while old objects tend to stay. This can be envisioned simply by realizing that memory objects representing compiled system routines, such as compilers and window managers, rarely become garbage, while dynamic data structures of the currently operating program tend to become garbage relatively frequently. The idea behind generational garbage collection is to collect the young objects more frequently, thereby making more efficient use of the collector to make memory available.
A description of features desirable in a garbage collection system can be found in A Real-Time Garbage Collector Based on the Lifetimes of Objects, Lieberman and Hewitt, Communications of the ACM, volume 26, number 6, pp. 419-429, 1983. This paper describes one possible system using generations of objects to improve efficiency of garbage collection.
It is an object of the present invention to provide a garbage collection system which can simply and efficiently garbage collect a large virtual address space.
Therefore, according to the present invention, the virtual address space of a computer system is conceptually divided into a number of different generations. Most objects are classified by generations depending on their age within the system. Objects in older generations are not allowed to contain pointers directly to objects in younger generations. Instead, pointers are routed through indirection cells which are located in separate parts of the address space. Use of such indirection cells greatly simplifies the task of keeping track of pointers into oldspace and pointers between generations. When garbage collection is run on a given generation, all of the pointers into the space to be collected are contained in a relatively small number of indirection cells. It is necessary to scavenge only the spaces containing these indirection cells in order to accomplish the garbage collection process.
The novel features which characterize the present invention are defined by the appended claims. The foregoing and other objects and advantages of the present invention will hereafter appear, and for purposes of illustration, but not of limitation, a preferred embodiment is shown in the accompanying drawings. | {
"pile_set_name": "USPTO Backgrounds"
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In connection with known thermostat valves, holding arms, on whose hook-shaped ends the cross arm is suspended, are attached to the cover-like housing member and project away from it. During operation, these holding arms are subjected to great stresses, so that the cover-like member is made of metal or a high-quality plastic material which can withstand these stresses. It is also known (DE 44 16 240 C1) to provide support elements on the main housing, to which the cover-like housing member is attached, and on which the cross arm is suspended during the assembly of the two housing members, so that the holding arms of the cover-like housing member are relieved. In most cases the main housing is an engine block or the housing of a water pump. Therefore, the manufacturer of the thermostat valve with the cover-like housing member is not the manufacturer of the main housing to which the cover-like housing member is attached. Thus, in many cases it is disadvantageous if the main housing must have a defined shape in order to take on the support function of the cross arm of the cover-like housing member. | {
"pile_set_name": "USPTO Backgrounds"
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Commercially available independent flow and pressure control systems for dispensing agrochemicals onto fields exist and are well documented in the prior art. These systems utilize a plurality of solenoid actuated valves that pulse according to a on/off ratio which determines the flow from the group of nozzles at any given pressure. Therefore, the pressure of the system can be controlled for such parameters as droplet size, system flow capacity, stream dynamics, injection penetration, etc., while the flow of the system is independently controlled for such parameters as application rate (gallons/acre). These systems are commercially available for agricultural liquid applications of pest control sprays and crop nutrient systems. All nozzles within these existing commercial systems pulse together at the same rate.
Such systems for dispensing agrochemicals as described above are described, for instance, in U.S. Pat. No. 5,967,066 and in U.S. Pat. No. 7,502,665, which are incorporated herein by reference. The systems described in the above patents include a liquid reservoir for containing an agrochemical placed in communication with a plurality of valves positioned on a boom. In the '665 patent, a networked delivery system is described that includes a communication network to establish operative communication between individual device nodes and a central operator interface. In the '665 patent, for instance, a plurality of vibration sensors can be located adjacent to respective nozzles or valves that indicate to the operator whether the valves are operating properly.
The systems described in the '066 patent and in the '665 patent represent great advances in the art. Although the systems described in the above patents, however, suggest controlling the application rate of the agrochemical based on individual solenoid valves, various improvements in the art are still needed.
In particular, a need currently exists for an improved system and method for controlling individual valves or groups of valves for varying application rates. A need also particularly exists for such a control system that is capable of being retrofitted onto existing systems. | {
"pile_set_name": "USPTO Backgrounds"
} |
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1. Field of the Invention
The invention is related to the field of call processing systems, and in particular, to a system that provides personalized and customized services for call center customers waiting in a queue.
2. Description of the Prior Art
Customers calling call centers typically wait in queues depending on the availability of service agents and/or voice response units. A call is in a queue when the call is waiting and not being processed due to predetermined logic or call center resource unavailability. During this waiting period, call centers play music or pre-recorded messages to prevent the customer from abandoning the call and to take advantage of the waiting period. Some examples of these pre-recorded messages are messages informing the customer their position in the queue and advertising messages. Advertisers who play their messages to queued callers target a general audience of call center customers.
There are two drawbacks with only having the ability to target a general audience of call center customers. First, the advertising is less effective than targeting specific call center customers. Advertising dollars are wasted on queued callers who may not fit the demographic targeted by the marketing campaign. Ineffective advertisement not only wastes advertising dollars but also wastes time for the disinterested caller. In cases where a campaign for new products targets specific call center customers, a service agent identifies if the caller fits within the targeted demographic and then reads a sales pitch or product information from a script. However, this requires a large commitment of the service agents"" time to sell products which prevents them from handling what the call was originally made for. Therefore, less customers are served, and call response time increases.
The second drawback is a decreased level of customer satisfaction with messaging for general audiences. Typically, the caller is already displeased with being placed in a queue. Hearing a message that the caller has no interest in can only serve to further annoy the caller. Also, the impression given to the customer is that the customer is only one of many that the call center is trying to serve.
The invention solves the above problem by providing service information to a call in a queue for a call center based on caller data. The provision of service information such as advertising messages, audio entertainment, and interactive applications based on caller data creates a personalized and customized service for the customer. Initially, the invention receives caller data for the call in the queue for the call center. Caller data is data related to the caller such as caller number, called number, and caller provided information. The invention then identifies the service information based on the caller data and provides the service information to the call in the queue.
Two advantages of the invention are providing the ability to target specific call center customers and providing a new platform of service information for the call in the queue. The first advantage of providing the ability to target specific call center customers is a cost effective advertising solution. Advertising to specific target audiences who are more likely to buy the product or service offered yields a greater return on the advertising dollar. Marketing campaigns can then be enhanced to pinpoint certain customers for new products and services. A customer who previously ordered a breadmaker can hear about the new improved breadmaker model. Other customers not interested in breadmaking will not be burdened with hearing about the new improved breadmaker model. The invention also eliminates the time and cost burdens of having agents identify potential targets for advertising campaigns. Instead, the invention automatically identifies the appropriate advertising message to provide to the call center customer, which frees up service agents from selling new products. Therefore, service agents have more time to serve more customers further reducing call response times.
The second advantage of providing new platforms to the caller waiting in the queue is improved call center customer satisfaction. New advertising messages targeted directly to the customer give the impression that the customer is the only customer that the call center is serving. Also, the new service information such as personalized advertising, caller requested audio entertainment, and interactive caller games keeps the caller entertained and engaged, which reduces the rate of call abandonment. | {
"pile_set_name": "USPTO Backgrounds"
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The present invention relates generally to indoor air-quality systems and more particularly to the operation of indoor air-quality systems with ultraviolet light sources.
Some known indoor air-quality systems include ultraviolet photocatalytic oxidation devices which remove gases such as volatile organic compounds from the air in heating ventilation and air-conditioning systems. These devices include ultraviolet light sources that direct ultraviolet light onto a photocatalyst on a substrate. The ultraviolet light sources must be replaced periodically, thus increasing the cost of maintaining the device. The more that the ultraviolet light sources are on, the more frequently they will have to be replaced.
In some installations, the ultraviolet light sources must be downstream of the air-conditioning evaporator coil. When the evaporator coil is activated, the air downstream is cold. Ultraviolet light sources are less effective when cold, so additional ultraviolet light sources are sometimes required when they are installed downstream of the evaporator coil. | {
"pile_set_name": "USPTO Backgrounds"
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The invention resides in a fuel injection system for an internal combustion engine with an injection pump providing for an initial fuel injection phase and a main fuel injection phase.
Such a fuel injection system is known for example from DE 37 22 265 A1. For the injection of fuel, a piston moving downwardly within an injection pump sucks in fuel by way of a fuel supply line. After closing of a control valve in the fuel injection pump, and with the communication through the line leading from the injection pump through the fuel injector interrupted by the closed fuel injection nozzle needle, the upwardly moving piston generates a high pressure in this line which is also designated high pressure space. As a result of the high pressure generated in this line, the injector's nozzle needle opens and fuel is injected into the combustion chamber of the internal combustion engine.
In addition to the control valve already referred to, the injection pump includes another control valve. One of the control valves is closed during the whole injection period, whereas the other control valve is opened for the termination of the fuel injection procedure.
The injection system described in this patent, however, has the disadvantage that the flow cross-section of the other control valve must be sufficiently large such that the injection procedure can be safely interrupted or, respectively, the initial injection can be terminated at maximum engine speed. However, such a large flow cross-section of the other valve results at a low engine speeds in a disadvantageous excessive pressure release from the high pressure space whereby cavities are formed which, in the end, lead to an unstable main fuel injection process.
Another fuel injection system for internal combustion engines is described in DE 36 01 710 A1. In this case, the flow cross-section of the electromagnetic valve is adjustable in at least two stages and the fuel injection volume is divided into an initial injection volume and a main injection volume. In order to achieve the initial injection, the valve is shortly closed and subsequently opened. It is then again closed for the main injection procedure and subsequently opened to terminate the main fuel injection phase.
With such an injection system, it is disadvantageous that the high pressure space is highly depressurized when the valve is opened at low engine speeds, because of the large flow cross-section of the valve whereby, as described above, cavities are formed which result in an unstable main injection process. Furthermore, during a non-ballistic operation of the magnetic valve, the initial injection volume generated by the pump operated at a relatively high speed is excessively large. Valve hammering occurring in the process, that is seating of the valve member on the valve seat at high speed, result in different injection volumes.
For the general state of the art of fuel injection systems, reference is further made to DE 31 47 467 C1 and to WO 89/00242 A1.
It is the object of the present invention to provide a fuel injection system for an internal combustion engine wherein excessive pressure release from the high pressure space at low engine speeds is avoided and a sufficiently small initial injection volume is provided at high engine speeds. | {
"pile_set_name": "USPTO Backgrounds"
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The traditional process of purchasing commercial color printing can be time consuming and error-prone. This has led businesses to rely on ad agencies and graphic designers to design and buy their printed materials. Unfortunately, the expense of ad agencies and design firms has made it cost-prohibitive for businesses, especially self-employed individuals and small businesses, to purchase professional quality printed materials.
The widespread growth of PC's and desktop publishing software has made it possible for anyone to design printed materials on their PC and furnish the digital layout file to a printer. However, these users do not always have an easy way to get professional-quality printing for their files. In addition, excess production capacity (idle presses) is a chronic problem in the capital-intensive printing industry. To solve this problem, printing services have made print orders available to printing companies through a bidding system that uses request for quotations.
This bidding system is time intensive because it requires a printing company to spend time estimating more jobs than it receives. For example, a printing company may enter bids on ten jobs, but only win the bid on five jobs. Thus, the printing company wasted time entering bids on jobs it did not receive. Further, this method of obtaining work is risky because the company is forced to bid on more work than it can do; thus, when a company underestimates the number of bids it will win, it may be left with more work than it can handle, or vice versa.
The bidding process used in the printing industry is also used by many other industries where production companies compete for work. In addition, other industries have production capacity issues, where it is difficult to control the flow of work from day to day.
There is a need for a system and method of matching job orders in a specific industry, such as the printing industry, with companies having excess production capacity in that industry. Further, there is a need to make the job orders instantly available to the companies in a standard format and at a fixed price, without requiring the production companies to incur the expense of generating price quotes in an attempt to capture orders. | {
"pile_set_name": "USPTO Backgrounds"
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Light emitting devices such as light emitting diodes (LEDs) based on group III-V nitride semiconductors such as gallium nitride (GaN) have been put into practice.
Since wide GaN substrate cannot be produced, the LEDs have been produced on a heteroepitaxial substrate such as sapphire. The use of sapphire substrate is problematic due to lattice mismatch and thermal expansion mismatch between GaN and the sapphire substrate. One consequence of thermal expansion mismatch is bowing of the GaN/sapphire substrate structure, which leads to cracking and difficulty in fabricating devices with small feature sizes. A solution for this is to form a plurality of grooves on the surface of the sapphire substrate by lithography or etching before growing the GaN layer. However, the process of lithography and etching is complex, high in cost, and will pollute the sapphire substrate.
What is needed, therefore, is to provide a method for solving the problem discussed above. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention concerns wire electrodes used in machining metal parts by spark erosion.
2. Description of the Prior Art
In this type of machining, as described in document FR-A-2 418 699 for example, a wire electrode is driven in longitudinal translation and a portion of said wire is guided and stretched along a straight line segment displaced laterally along a path in the vicinity of a metal part to be machined. An electrical generator produces a potential difference between the part to be machined and the metal wire forming the electrode. Machining occurs in the machining area between the wire electrode and the metal part and progressively erodes the part and the wire.
Improvements to the quality of spark erosion electrode wire have been sought for a long time, combining good mechanical resistance to traction, good electrical conductivity of the wire and more regular production of the eroding sparks in the machining area between the electrode wire and the part to be machined.
For example, document U.S. Pat. No. 4,287,404 describes a method and device for making a spark erosion electrode wire having a wire core surrounded by a layer with a low boiling point, such as zinc, cadmium, tin, lead, antimony and bismuth. The outer metal layer is deposited by a step of cold electrolytic deposition from a bath of metal salt in aqueous solution, followed by a drawing step. A method of this kind has the drawback of producing electrode wire in which the outer layer vaporizes too quickly and provides insufficient protection of the core during spark erosion.
It has been found advantageous to heat the wire after electrolytic deposition of the surface layer of metal with a low boiling point, to form a diffused alloy, as taught in document EP-A-0 185 492. However, a process of this kind cannot be used to produce an electrode wire with a surface layer of diffused alloy in which the thickness and the structure are perfectly controlled.
Document U.S. Pat. No. 4,169,426 describes another method of producing a spark erosion electrode wire having a wire core surrounded by a metal layer, in which a conductive wire is passed continuously through a bath of molten metal and then quickly cooled to prevent intermetallic compounds forming at the interface between the wire core and the outer metal layer. The wire is then heat treated for several minutes at 320.degree. C. before it is drawn to the required final diameter. A method of this kind also has the disadvantage that the thickness and the structure of the coating are not totally controlled.
Document CH-A-655 265 proposes preheating the conductive wire by the Joule effect by passing an appropriate electric current through it before it enters a bath of molten metal.
Document EP-A-0 811 701 teaches a similar method of producing spark erosion wire by passing the wire through a bath of molten metal, in which the wire is heated by the Joule effect while passing through the bath of molten metal. This method is no better than the previous ones in terms of controlling the thickness and structure of the coating.
During fabrication of a spark erosion electrode wire by any of the methods mentioned above, it is particularly difficult to adjust the quantity of deposited metal forming the coating, and above all the proportion of diffused metal, and consequently the nature of the alloy phases obtained. For example, in the method of document EP-A-0 185 492, thermal diffusion of the metals is very sensitive to the temperature of the wire and the heating time, and so obtaining a particular structure of the distribution of the metal concentrations in the coating requires very accurate control of the wire heating conditions during the diffusion step, which is difficult to achieve in an industrial process. What is more, it is not possible to obtain a wire structure having a surface layer of pure zinc covering an intermediate diffused brass layer in one simple operation.
The problem is that the coating of the spark erosion electrode wire must be sufficiently thick to constitute the wear layer when the wire is used for spark erosion machining and must have satisfactory properties suited to the machining conditions that will apply. A diffused brass layer having a .beta. phase crystalline structure, favoring a higher speed of spark erosion, is desirable, in particular. However, obtaining the .beta. phase layer is highly dependent on the temperature conditions during the diffusion step, and it is difficult to achieve consistent industrial production that is perfectly controlled.
Document FR-A-2 502 647 concerns a method of brass-plating metal parts such as a long wire for use in tire armatures. A thin (0.28 .mu.) copper layer is deposited on an iron core, after which a zinc layer is applied electrolytically and the wire is heated to assure complete diffusion of the copper and the zinc, forming an .alpha. brass layer encouraging adhesion between the wire and the rubber of the tire. The coating obtained on the wire is too thin to be usable for spark erosion and the .alpha. brass is not suitable for spark erosion. The method employed would not be able to produce wire with a coating of sufficient thickness for spark erosion.
The problem addressed by the present invention is that of designing simple and inexpensive means for significantly enhancing the possibilities and the flexibility of manufacture of spark erosion electrode wires including at least one diffused alloy or metal layer around an electrically conductive wire core. To adapt the structure of the electrode wire to varying requirements it is necessary to be able to vary at will the concentration of metals in the various layers forming the coating and the thickness of the layers.
In an improvement on the invention, the aim is simultaneously to improve the adhesion of the metal or alloy layer to the core, to enable subsequent drawing of the wire without significant deterioration of the outer metal layer.
Another object of the invention is to provide a means of forming a metal or alloy layer of the above kind at will whose surface portion contains a high proportion of a metal with a low boiling point, such as zinc, cadmium, tin, lead, antimony or bismuth. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to portable circular saws.
2. Description of the Prior Art
In general, portable circular saws include a housing enclosing an electric motor therein, a handle carried by the housing, a circular saw blade operatively connected to the electric motor, a blade case fixed to the housing and adapted to enclose substantially the upper half of the saw blade, a base plate for supporting the housing thereon, and a safety cover pivotally mounted on the housing and adapted to cover substantially the lower half of the saw blade projecting from the base plate. In one common construction for such circular saws, the housing is mounted on the front and rear ends of the base plate for pivotal movement in both the longitudinal and transverse directions of the base plate. Thus, the amount of projection of the circular saw blade below the base plate may be adjusted and further, the tilt angle of the circular saw blade relative to the base plate may be adjusted. In some designs, the drive shaft of the motor is arranged in parallel to the circular saw blade, and the handle is located at the rear portion of the whole saw.
In any of the above described conventional circular saws, when it is desired to temporarily rest the saw on a work site or the like in practice, it must be supported on a side edge of the base plate and the safety cover covering the lower half of the circular saw blade projecting from the base plate. While the circular saw is in its rest position, the base plate is transversely tilted, or the saw body is transversely tilted.
In many cases, however, the portable circular saw is operated to cut a workpiece with the base plate held upright with respect to the horizontal plane. If the operation is completed by a single cut, no problem will be caused in the operating performance of the circular saw which is set in the transversely tilted rest position as mentioned above. However, when several continuous cutting operations are performed, a series of actions have to be repeated, which includes gripping the handle, raising up the saw body from the tilted rest position to the upright position to cut a workpiece and, after cutting the workpiece, replacing the saw body to the transversely tilted position. In particular, the action of raising up the saw body from the transversely tilted rest position to the upright position has to be repeated at every cutting operation, thus reducing the efficiency in use.
Further, when the safety cover pivotally covering the circular saw blade is rested on a work site as described above, the safety cover may be unexpectedly pivoted to expose the cutting edge of the circular saw blade, thereby resulting in a serious accident. | {
"pile_set_name": "USPTO Backgrounds"
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To prevent fires, and the resulting loss of life and property, the use of flame detectors or flame detection systems is not only voluntarily adopted in many situations, but is also required by the appropriate authority for implementing the National Fire Protection Association's (NFPA) codes, standards, and regulations. Facilities faced with a constant threat of fire, such as petrochemical facilities and refineries, semiconductor fabrication plants, paint facilities, co-generation plants, aircraft hangers, silane gas storage facilities, gas turbines and power plants, gas compressor stations, munitions plants, airbag manufacturing plants, and so on are examples of environments that typically require constant monitoring and response to fires and potential fire hazard situations.
To convey the significance of the fire detection system and process proposed by this patent application, an exemplary environment, in which electrostatic coating or spraying operations are performed, is explained in some detail. However, it should be understood that the present invention may be practiced in any environment faced with a threat of fire.
Electrostatic coating or spraying is a popular technique for large scale application of paint, as for example, in a production painting line for automobiles and large appliances. Electrostatic coating or spraying involves the movement of very small droplets of electrically charged "liquid" paint or particles of electrically charged "Powder" paint from an electrically charged (40 to 120,000 volts) nozzle to the surface of a part to be coated.
While facilitating efficiency, environmental benefits, and many production advantages, electrostatic coating of parts in a production paint line, presents an environment fraught with fire hazards and safety concerns. For example, sparks are common from improperly grounded workpieces or faulty spray guns. In instances where the coating material is a paint having a volatile solvent, the danger of a fire from sparking, or arcing, is, in fact, quite serious. Fires are also a possibility if electrical arcs occur between charged objects and a grounded conductor in the vicinity of flammable vapors.
Flame detectors have routinely been located at strategic positions in spray booths, to monitor any fires that may occur and to shut down the electrostatics, paint flow to the gun, and conveyors in order to cut off the contributing factors leading to the fire.
Three primary contributing factors to a fire are: (1) fuel, such as atomized paint spray, solvents, and paint residues; (2) heat such as derived from electrostatic corona discharges, sparking, and arcing from ungrounded workpieces, and so on; and (3) oxygen. If the fuel is heated above its ignition temperature (or "flash point") in the presence of oxygen, then a fire will occur.
An electrical spark can cause the temperature of a fuel to exceed its ignition temperature. For example, in a matter of seconds, a liquid spray gun fire can result from an ungrounded workpiece producing sparks, as the spray gun normally operates at very high voltages (in the 40,000 to 120,000 volt range). An electrical spark can cause the paint (fuel) to exceed its ignition temperature. The resulting spray gun fire can quickly produce radiant thermal energy sufficient to raise the temperature of the nearby paint residue on the booth walls or floor, causing the fire to quickly spread throughout the paint booth.
A fire may self-extinguish if one of the three above mentioned factors is eliminated. Thus, if the fuel supply of the fire is cut off, the fire typically stops. If a fire fails to self-extinguish, flame detectors are expected to activate suppression agents to extinguish the fire and thereby prevent major damage.
Flame detectors, which are an integral part of industrial operations such as the one described above, must meet standards set by the NFPA, which standards are becoming increasingly stringent. Thus, increased sensitivity, faster reaction times, and fewer false alarms are not only desirable, but are now a requirement.
Previous flame detectors have had many drawbacks. The drawbacks of these previous devices have led to false alarms which unnecessarily stop production or activate fire suppression systems when no fire is present. These prior flame detectors have also failed to detect fires upon occasion, resulting in damage to the facilities in which they have been deployed and/or financial repercussions due to work stoppage or damaged inventory and equipment caused by improper release of the fire suppressant.
One drawback of the most common types of flame detectors is that they can only sense radiant energy in one or more of either the ultraviolet, visible, near band infrared (IR), or carbon dioxide (CO.sub.2) 4.3 micron band spectra. Such flame detectors tend to be unreliable and can fail to distinguish false alarms, including those caused by non-fire radiant energy sources (such as industrial ovens), or controlled fire sources that are not dangerous (such as a lighter). Disrupting an automated process in response to a false alarm can, as noted, have tremendous financial setbacks.
Another drawback of previous fire detectors is their lack of reliability, which can be viewed as largely stemming from their approach to fire detection. The most advanced fire detectors available tend to involve simple microprocessor controls and processing software of roughly the same complexity as those used for controlling microwave ovens. The sensitivity levels of these previous devices are usually calibrated only once, during manufacture. However, the sensitivity levels often change as time passes, causing such conventional flame detectors to fail to detect real fires or to false alarm.
Many of the conventional flame detectors also are limited by their utilization of pyroelectric sensors, which detect only the change in radiant heat emitted from a fire. Such pyroelectric sensors depend upon temperature changes caused by radiant energy fluctuations, and are susceptible to premature aging and degraded sensitivity and stability with the passage of time. In addition, such pyroelectric sensors do not take into account natural temperature variations resulting from environmental temperature changes that occur, typically during the day, as a result of seasonal changes or prevailing climatic conditions.
Other types of conventional flame detectors identify fires by relying primarily on the ability to detect a unique narrow band spectral emissions radiated from hot CO.sub.2 (carbon dioxide) fumes produced by the fire. Hot CO.sub.2 gas from a fire emits a narrow band of radiant energy at a wavelength of approximately 4.3 microns. However, cold CO.sub.2 (a common fire suppression agent) absorbs energy at 4.3 microns, and can therefore absorb a hot CO.sub.2 spike emission generated by a fire. In such situations, conventional CO.sub.2 -based flame detectors can miss detecting a fire.
Another type of conventional IR flame detector monitors radiant energy in two infrared frequency bands, typically the 4.3 micron frequency band and the 3.8 micron frequency band, while others use as many as three infrared frequency bands. The dual IR frequency band flame detector commonly utilizes an analog signal subtraction technique for subtracting a reference sensor reading at approximately 3.8 microns from the sensed reading of CO.sub.2 at approximately 4.3 microns. The triple IR frequency band flame detector uses an analogous technique, with an additional reference band at approximately 5 microns. These types of multi-band flame detectors can false alarm when cold CO.sub.2 obscures the fire source from the flame detector, thereby misleading the detector into believing that a strong CO.sub.2 emission spike from a fire is detected, when, in fact, a negative absorption spike (caused by e.g., a CO.sub.2 suppression agent discharge or leak) has been detected.
Conventional flame detectors using ultraviolet ("UV") sensors also exist, but these too have drawbacks. Flame detectors with UV sensors may be sensitive to electrostatic spray gun flashes and corona discharges from waterborne coatings, which can cause false alarms and needlessly shut down production in paint spray booths. Also, because arc welding produces copious amounts of intense ultraviolet energy which can be reflected or transmitted over long distances, UV flame detectors can generate false alarms from such UV energy sources, even when the non-fire UV energy is located at a far distance from the spray booth. Moreover, after deployment, conventional UV detectors eventually can become highly de-sensitized as a result of absorbing smoke from a fire and/or solvent mist, causing the UV detector to become blinded. As a result, UV detectors can provide a false sense of security that they are operating at their optimum performance levels, when, in fact, the facility may be vulnerable to a costly fire.
As an additional disadvantage, UV flame detectors generally require a relatively clean viewing window lens for the UV sensor, and can therefore become blinded or degraded by the presence of paint or oil contaminants on the viewing window lens. Moreover, the sensing techniques utilized with conventional UV detectors usually do not take into account the effects of such types of degradation.
Besides problems with flame detection, many or all conventional flame detectors also have limitations or drawbacks relating to their housing and/or mounting that can affect their performance or longevity, in addition to being relatively expensive to manufacture. For example, most optical flame detectors have been built with metal housing made from costly aluminum, stainless steel, or similar materials. Such housings can be heavy, difficult to mount and may riot be suitable for certain corrosive environments such as "wet-benches" used in semiconductor fabrication facilities for manufacturing silicon chips and the like.
Further, most or all optical flare detector housings require a window lens (necessary for high optical transmission in the spectral bands used, and typically made of glass, quartz, sapphire, etc.), but it is usually quite difficult to obtain a tight seal of the window lens to metal housings, particularly in chemical manufacturing, or integrated circuit manufacturing or other applications having extremely rigorous environmental requirements. If the flame detector is not: tightly sealed, then corrosive chemicals can leak into the electronic circuitry and degrade or destroy the unit.
In flame detectors that detect UV energy, the protective window lens must be constructed from highly expensive quartz, sapphire, or other similar material that does not block UV energy. Moreover, the quartz or sapphire window lenses are typically placed in a metal detector housing, and are collectors of dust and contaminants due to the electrostatic effect of the high voltage field (around 300 to 400 volts) used in the UV detectors. To ensure that the UV detector's sensor(s) can "see through" the window lens, complex and costly "through the lens" tests are necessary. To conduct built-in "through the lens" window lens tests, a UV source tube is generally required to generate a UV test signal. Such UV source tubes require a high voltage for gas discharge sources and/or a large current for incandescent sources. Also, UV source tubes are subject to high failure rates. In sum, these self tests are expensive, require extra power and space, and are prone to breakdowns.
There is a need for a sensitive, reliable, fully enclosed, inexpensive, light-weight, intelligent, and effective method and system for detecting sparks, flames, or fire with little or no interruptions caused by false alarms. | {
"pile_set_name": "USPTO Backgrounds"
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Polybutadiene has a so-called microstructure in which a binding segment formed by polymerization at the 1,4-positions (1,4-structure) and a binding segment formed by polymerization at the 1,2-positions (1,2-structure) are copresent in the molecular chain. The 1,4-structure is further classified into a cis-structure and a trans-structure. On the other hand, the 1,2-structure takes a structure containing a vinyl group as a side chain.
Hitherto, a production process of a vinyl-cis-polybutadiene rubber composition has been carried out in an aromatic hydrocarbon-based solvent such as benzene, toluene, and xylene. When such a solvent is used, since the viscosity of a polymerization solution is high, there were problems in stirring, heat transfer, delivery, and so on, and excessive energy was required for recovering the solvent.
As the foregoing production process, there is known a process in which 1,3-butadiene is subjected to cis-1,4-polymerization in the foregoing inert organic solvent by using a catalyst obtainable from water, a soluble cobalt compound and an organoaluminum chloride represented by the general formula, AlRnX3−n, (wherein R represents an alkyl group having from 1 to 6 carbon atoms, a phenyl group, or a cycloalkyl group; X represents a halogen atom; and n represents a numeral of from 1.5 to 2) to produce BR, and 1,3-butadiene is then subjected to syndiotactic 1,2-polymerization (hereinafter abbreviated as “1,2-polymerization”) in the presence of a catalyst obtainable from a soluble cobalt compound, an organoaluminum compound represented by the general formula, AlR3 (wherein R represents an alkyl group having from 1 to 6 carbon atoms, a phenyl group or a cycloalkyl group) and carbon disulfide by adding or not adding 1,3-butadiene and/or the foregoing solvent to this polymerization system (see, for example, JP-B-49-17666 (Patent Document 1) and JP-B-49-17667 (Patent Document 2)).
Furthermore, for example, JP-B-62-171 (Patent Document 3), JP-B-63-36324 (Patent Document 4), JP-B-2-37927 (Patent Document 5), JP-B-2-38081 (Patent Document 6) and JP-B-3-63566 (Patent Document 7) describe a process in which the production is carried out by subjecting 1,3-butadiene to cis-1,4-polymerization in the presence or absence of carbon disulfide, or after the production, 1,3-butadiene and carbon disulfide are separated and recovered, thereby circulating 1,3-butadiene not substantially containing carbon disulfide or the foregoing inert organic solvent. In addition, JP-B-4-48815 (Patent Document 8) describes a rubber composition having excellent tensile stress and flex crack growth resistance, in which a compounded material thereof has a small die swell ratio and a vulcanizate thereof is suitable as a sidewall of tire.
Furthermore, JP-A-2000-44633 (Patent Document 9) describes a process in which the production is carried out in an inert organic solvent containing, as the major component, a C4 fraction such as n-butane, cis-2-butene, trans-2-butene, and butene-1. It is described that in this process, 1,2-polybutadiene contained in the rubber composition is a short fiber crystal, and the distribution of the major axis length of the short fiber crystal is such that 98% or more of the fiber length is less than 0.6 μm and 70% or more thereof is less than 0.2 μm. Also, it is described that in the resulting rubber composition, the moldability, tensile stress, tensile strength and flex crack growth resistance of a cis-1,4-polybutadiene rubber (hereinafter abbreviated as “BR”) are improved.
However, it is desired that not only the moldability is further enhanced, but also various characteristics are improved depending upon the utility. Furthermore, the foregoing vinyl-cis-polybutadiene rubber involved such a defect that it is inferior to usual high cis-polybutadiene with respect to exothermic characteristics and rebound resilience.
Furthermore, in general, it is known that a proportion of the tire rolling resistance occupying in the running resistance which largely affects the fuel consumption of an automobile is large and that the affect due to an energy loss of sidewall rubber is relatively large. For that reason, rubbers having a low dissipation factor such as natural rubbers, isoprene rubbers, butadiene rubbers, and mixtures thereof have hitherto been used in the sidewall part. However, it is required that the rolling resistance of tire is further improved.
As a method for reducing the dissipation factor of the sidewall rubber, the use of carbon black having low reinforcing properties or a reduction of the compounding amount of carbon black may be thought. However, there is encountered such a problem that the die swell at the time of extrusion processing becomes large, and therefore, it is difficult to make the thickness of the sidewall member thin or to realize an enhancement of uniformity of tire. For that reason, there is demanded a method for realizing low fuel consumption while keeping a small die swell with respect to an extrudate thereof.
Furthermore, in general, with respect to the performance of automobile tire, there are required excellent wet skid properties as a braking characteristic and excellent rolling resistance (tan δ) or abrasion resistance as a fuel consumption characteristic. However, it is known that these characteristics are in an antinomy relation with each other. In recent years, though there has been made a proposal to compound silica having excellent wet skid properties, thereby highly balancing the foregoing characteristics, such is not satisfactory yet. It is known that though the silica compounding is excellent in the wet skid properties and fuel consumption properties, the abrasion resistance and processability are lowered. While the abrasion resistance is improved by the use of high cis-BR, there is some possibility that the wet skid properties are lowered, and therefore, improvements were demanded.
Furthermore, in general, tires are required to have excellent drivability and durability and so on. In particular, from the standpoint of safety, the tires are required to have excellent wet skid resistance on a wet road surface. Moreover, on the basis of social requirements for realizing conservation of natural resources in recent years, tires having a low rolling resistance, namely tires with a low energy loss, are being researched and developed. While the energy loss of tire as consumed by free rotation varies depending upon the tire structure, etc., about a half of the whole energy is consumed in the tread part. Accordingly, if the energy loss of the tread rubber is reduced, a tire with a low energy loss at the time of rolling is obtained.
Then, it is attempted to modify the tread rubber such that the energy loss is low. However, such modification of the rubber tends to lower the wet skid properties. Since an improvement of the rolling resistance and an improvement of the wet skid properties generally contradict to each other, various designs for the improvements in the tire structure are attempted in order to make them compatible with each other. As one of the designs, there is enumerated a method for forming a tread into two layers consisting of a cap tread and a base tread. That is, this method is to form the tread into two layers of a cap tread with excellent wet skid properties and a base tread with a low energy loss, thereby not only enhancing the wet skid properties of tire as a whole but also lowering the energy loss.
The rubber for cap tread is required to have a high elastic modulus and molding stability derived from the abrasion resistance and high-speed running properties in addition to the wet skid properties. As a method for obtaining a rubber with a high elastic modulus, various methods have hitherto been attempted. The method for compounding a large amount of carbon black is not preferable because unification of rubbers is poor in the processing step, an electrical power load increases at the time of kneading or extrusion, and ML of the compounded material becomes large, whereby difficulty is accompanied at the time of extrusion molding. The method for compounding a large amount of sulfur involves such defects that sulfur causes blooming and that the crack growth becomes fast due to an increase of the degree of crosslinking. With respect to the addition of a thermosetting resin, since the thermosetting resin is low in compatibility with usually used natural rubbers or diene-based rubbers, when a large amount of the thermosetting resin is compounded, satisfactory dispersion is hardly obtained. Furthermore, since this mixed compound is hard even in an unvulcanized state, the load may become large in kneading or extrusion, or the molding processability of tire may be deteriorated. In a method for merely blending and compounding single fibers, since binding between short fibers and the rubber is insufficient, creep may become large, or fatigue life may be lowered.
As the rubber for base tread, a rubber with low exothermic characteristics is required. Examples of rubbers with low exothermic characteristics include natural rubbers, isoprene rubbers, and cis-1,4-polybutadiene rubbers, and compounded materials of such a rubber with carbon black are used. In order to reveal low exothermic characteristics by other materials than rubbers, it may be thought to use carbon black having a large particle size and low reinforcing properties or to lower the compounding amount of carbon black. However, these methods involve such problems that the elastic modulus or fatigue resistance of rubber is lowered and that the die swell becomes large. Furthermore, there is a method for revealing low exothermic characteristics by compounding short fibers of nylon or vinylon, thereby making the rubber have a high elastic modulus. However, since these short fibers are insufficient in adhesion to rubbers, there is encountered a problem that the fatigue life is short.
On the other hand, when a cap/base system is employed in passenger automobile tires, at the time of co-extrusion of a cap tread and a base tread, there is caused a problem that an extrudate is warped because of a difference in die swell between the both members. If the die swell of the base tread rubber is made small, this problem is liable to be solved. If a large amount of carbon black with high reinforcing properties is compounded, though the die swell become small, the heat generation becomes large. Thus, a method which is satisfied with the die swell and low heat generation at the same time is desired.
Furthermore, in general, in radial tires, a steel cord is used in view of high-speed durability and high-speed drivability. In the case of using a steel cord, a very large strain is liable to be gathered in a rubber in the vicinity of the steel cord at the time of running of tire. Accordingly, the rubber for steel cord is required to have a high elastic modulus and excellent adhesiveness to metals. Even in radial tires or bias tires using an organic fiber cord, rubbers having a high elastic modulus are preferable as the rubber for cord from the viewpoint of durability.
As a method for obtaining a rubber with a high elastic modulus, various methods have hitherto been attempted. The method for compounding a large amount of carbon black is not preferable because unification of rubbers is poor in the processing step, an electrical power load increases at the time of kneading or extrusion, and ML of the compounded material becomes large, whereby difficulty is accompanied at the time of extrusion molding. The method for compounding a large amount of sulfur involves such defects that sulfur causes blooming and that the crack growth becomes fast due to an increase of the degree of crosslinking. With respect to the addition of a thermosetting resin, since the thermosetting resin is low in compatibility with natural rubbers or diene-based rubbers as usually used as a cord coating rubber, dispersion failure likely occurs, and crack resistance is deteriorated. Furthermore, conventionally known tire cord coating rubber compositions are small in green strength. Thus, materials having a large green strength are required in view of molding processability.
Furthermore, in general, as rubber members to be disposed in the surroundings of tire bead, high-hardness rubbers are used. Examples thereof include a rubber composition having an increased compounding amount of carbon black and a rubber composition having a novolak type phenol resin compounded therein (see JP-B-57-30856) and a rubber composition having short fibers and an olefin-based resin compounded therein (see JP-A-7-315014).
With respect to a method for obtaining a high-hardness rubber composition, it is general to increase carbon black or to compound a fiber, a resin, etc. However, in all of these methods, there may be the case where the heat generation at the time of repeated deformation becomes large, whereby the durability and fatigue resistance are lowered. Thus, improvements are required.
Patent Document 1: JP-B-49-17666
Patent Document 2: JP-B-49-17667
Patent Document 3: JP-B-62-171
Patent Document 4: JP-B-63-36324
Patent Document 5: JP-B-2-37927
Patent Document 6: JP-B-2-38081
Patent Document 7: JP-B-3-63566
Patent Document 8: JP-B-4-48815
Patent Document 9: JP-A-2000-44633 | {
"pile_set_name": "USPTO Backgrounds"
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The invention relates to a device for connecting components made of fusible plastic, particularly pipes of a fuel line, or for connecting a fuel line with a fuel tank of a vehicle.
European patent application no. EP 919,761 discloses a device of this type which comprises a sleeve body for connecting two pipe ends. In the inside surface of the substantially hollow cylindrical sleeve body a heating element is arranged, which is configured as a heating coil made of resistance wire and to which a current or electric energy can be applied. The wire ends of the heating element configured as a heating coil extend to the exterior into sockets. With corresponding contacts of connecting lines, the electrical connection with a welding device can be established to supply the heating element with current and thereby to heat the plastic so that an electric weld is produced.
Such electric welding sleeves have been used very successfully to connect pipes in supply networks, e.g., water pipes or gas pipes. However, the personnel must be experienced in handling the welding device and producing the electric weld, and the welding operation has to be carefully prepared and executed. Also, the production of such welding sleeves, particularly with respect to the contacting of the wire ends in said sockets is quite complex. To prepare and execute the electric welding operation, various actions must be performed manually, which involves a considerable amount of time and assembly.
Especially in automotive fuel tank systems with a plastic fuel tank and a plastic fuel line that is to be connected therewith, the current joining techniques consist of using hose connecting clamps or butt-welding of the connecting points with heat reflectors. The drawback is that there is no adequate diffusion barrier and complex assembly is required during production, especially since a variety of different components are required. Also, any repair or replacement of individual components requires a substantial amount of time.
In addition, there is the problem of positioning add-on devices, e.g., fuel pump, hose holder, sensors, etc. in and on the tank. The currently used butt-welding process with heat reflectors is difficult, especially in the interior of the tank and/or on surfaces that are not flat. It should moreover be noted that for diffusion reasons, all additional openings on the fuel tank should be avoided, so that the positioning of additional devices in areas of the tank that are remote and/or difficult to access requires a significant amount of time and is often not possible without an auxiliary opening.
When add-on devices or other parts are butt-welded with heat reflectors in the interior of the tank, a heat reflector is brought to the welding position through the existing tank opening, i.e., the opening for the tank fitting, by means of a complex telescope mechanism in order to melt the tank wall at that point. Since the additional device cannot be carried along directly for lack of space, the heat reflector must first be withdrawn and the additional device must then be brought to the desired position. Since a properly welded joint requires a predefined welding temperature and contact pressure, process control is very difficult and costly. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to ultrasonic vibration welders.
2. Description of the Related Art
Various ultrasonic vibration welders for welding stacked ultrasonic-weldable parts, such as metal parts or plastic parts, by applying ultrasonic vibration and welding pressure are in practical use. Japanese Patent No. 2756433 discloses one of such ultrasonic vibration welders. FIG. 10 shows a relevant part of the ultrasonic vibration welder.
Referring to FIG. 10, an ultrasonic vibration welder 100 includes a generator 101 that generates an electrical frequency, an oscillator 102 that converts the electrical frequency generated by the generator 101 into mechanical vibration, a horn 103 that amplifies the vibration, the horn 103 being fixed to the oscillator 102 at one end and thinned at the other end, a vibration transmission rod 104 joined to the thinned end of the horn 103 in such a manner that it extends perpendicularly to the axis of the horn 103, a mass 104A serving as a resonator for applying pressure, and a pressure applicator 105 connected to the mass 104A. The horn 103 and the vibration transmission rod 104 are joined together by welding or brazing. The ultrasonic vibration welder 100 further includes a chip 106 attached to an end of the vibration transmission rod 104, an anvil 107 arranged at a position facing the chip 106, and an anvil base 108 that supports the anvil 107. Parts to be welded together are denoted by W and W.
In the ultrasonic vibration welder 100, the horn 103 causes the vibration transmission rod 104 to perform flexural vibration, while the pressure applicator 105 applies welding pressure to the vibration transmission rod 104, thereby causing friction between the parts W and W. The friction generates frictional heat, which diffuses or melt-bonds the parts W and W at portions subjected to friction. Thus, the parts W and W are welded together.
The vibration transmission rod 104 of the ultrasonic vibration welder 100 has a circular cross section. This means that the vibration transmission rod 104 resonates at a single frequency when flexural vibration is applied to the central axis thereof in any direction. There is no guarantee that the vibration transmission rod 104 always vibrates in the axial direction of the horn 103, which is an ideal vibration direction, during welding. Depending on the state of the load applied to a connecting portion between the vibration transmission rod 104 and the horn 103, the vibration transmission rod 104 can vibrate in a direction oblique to the axis of the horn 103, which is not an ideal vibration direction. However, the ultrasonic vibration welder 100 has no structure for solving this problem. Accordingly, there is a problem in that the connecting portion between the vibration transmission rod 104 and the horn 103 connected to the oscillator 102 has a tendency to get damaged.
Ultrasonic vibration generated by the oscillator 102 and the horn 103 is transmitted to the chip 106 through the vibration transmission rod 104. At the same time, welding pressure is applied to the parts W and W through the pressure applicator 105, the vibration transmission rod 104, and the chip 106. This structure has the problems described below.
The chip 106, which is brought into contact with the parts W and W during welding, is attached to an end of the vibration transmission rod 104. The problems lie in the structure in which the separately formed chip 106 and vibration transmission rod 104 are connected together. Examples of methods for attaching the chip 106 to an end of the vibration transmission rod 104 include a screw-in method as shown in FIG. 10 and a taper shank method (not shown).
In the case of an ultrasonic vibration welder that employs a screw-in method, a copper washer (not shown) is disposed between surfaces to be joined by a screw. However, the copper washer is degraded by heat and ultrasonic vibration transmission stress, and therefore the ultrasonic vibration welder cannot endure long-term use (after it is used about 5000 to 10000 times). In addition, if chips are screwed into ends of vibration transmission rods with a predetermined fastening force, the orientation of chip patterns with respect to the vibration direction varies. Accordingly, an ultrasonic vibration welder that employs a screw-in method cannot be used to weld parts that require the chip pattern and the ultrasonic vibration direction to be properly set.
In the case of an ultrasonic vibration welder that employs a taper shank method, it is possible to make chip patterns be oriented in the same direction with respect to the vibration direction. However, because chips are press-fitted to vibration transmission rods, the chips tend to drop or the fitting therebetween tends to become loose if the welding pressure during vibration is low. Thus, when tuning vibration, parts to be welded need to be disposed between the chip and the anvil while sufficient welding pressure with which normal vibration can be obtained is applied thereto. Further, in the case of welding products that require application of ultrasonic vibration under low pressure, such as small parts or thin parts, it is impossible to apply normal ultrasonic vibration because the welding pressure cannot be reduced during welding. Accordingly, it is impossible to weld such products. In addition, the vibration transmission rod is not durable. Because both the ultrasonic vibration and the welding pressure are transmitted to the chip through the vibration transmission rod, when welding is performed under high pressure, a shank portion of the vibration transmission rod is deformed and expanded.
In the known ultrasonic vibration welder 100, the mass 104A is formed integrally with the vibration transmission rod 104 at the end opposite the end to which the chip 106 is attached. Thus, when the vibration transmission rod 104 needs to be replaced for the reasons described above, the mass 104A also needs to be replaced. This is not cost effective. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention generally relates to separators for electrochemical cells and batteries and more particularly to electrodes which have separators incorporated therein.
2. Prior Art
Certain types of batteries require substantial circulation or irrigation of the electrolyte and in such instances the electrodes must be exposed to the electrolyte while still maintaining their relative positions within the battery. Electrodes have therefore been proposed which have separator particles imbedded in their surfaces but protruding therefrom a sufficient distance to maintain the separation of the electrode from another electrode of opposite polarity. The embedment procedure usually involves having to etch beads of electrically insulative material to cause them to have sufficient mechanical hold to the material lining the cavities in the electrode surface, which cavities have been provided during the embedment. It has been found that such embedment must be to the depth of at least 50% of the bead diameter in order to securely lock the beads in place. In order to assure such deep embedment, the electrode surface must be selected so that it is sufficiently malleable to permit considerable cold flow of material up around the bead without having to apply sufficient embedding force to crush the bead. A second conventional procedure for integrating separator pieces with the surfaces of an electrode involves punching out the separator pieces from a sheet and in the same operation causing them to adhere to the surface of the electrode plate. The equipment needed for such an operation is relatively complicated and sophisticated. Moreover, there are severe limitations on the materials which can be used for separators under such circumstances.
It would be desirable to be able to provide an improved method of integrating separator particles with an electrode surface so as to more rapidly and easily provide the electrode with an integral separator and without previously encountered limitations on the nature of the separator particles and on the nature of the electrode surface. Such method should preferably be inexpensive, utilize conventional materials and provide a durable product. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention generally relates implantable medical systems and, in particular, to systems, devices and methods for detecting incipient edema.
2. Description of the Prior Art
Pulmonary edema is often associated with heart failure.
In a healthy patient, the small alveoli in the lungs are filled with air. Close to the alveoli is a thin interstitial space, filled with interstitial fluid, which is different from blood. For example, the interstitial fluid contain no red blood cells. The interstitial space is also in close connection with capillaries filled with blood. Oxygen in the alveoli is diffusing into the interstitial space and then into the blood in the capillaries.
Development of pulmonary edema occurs gradually. For example, pulmonary edema may be a consequence of a heart failure. When the heart acquires a heart failure, the left arterial pressure and thereby the pressure in the capillaries will increase during a first phase. In this phase, no edema is present. In a second phase, the interstitial space between the alveoli and the capillaries is filled with more fluid, i.e., a swelling of the interstitial space occurs. The volume of the interstitial space increases with about two deciliters. In the following third, exacerbated phase, when the left arterial pressure has increased above 20, 25 mmHg, fluid enters the alveoli. Fluid in the alveoli diminishes the degree of oxygenation of the blood which weakens the heart and causes peripheral vasodilatation. The peripheral vasodilatation increases venous return from the peripheral circulation, which further increases the damming of blood in the alveoli, and thus, further diminishes the degree of oxygenation of the blood. This course of events may eventually lead to death of the patient. Pulmonary edema may develop so rapidly that death can occur within 20 minutes to an hour. Consequently, early detection of incipient edema is critical.
Pulmonary edema may be detected by using transthoracic impedance and through impedance measured between two implanted electrodes, covering one of the lungs. Edema has also been detected by listening to lung sounds.
Further, in U.S. Pat. No. 6,332,091, detection of pulmonary edema using infrared light is described. In a non-invasive method, a lung is exposed to infrared light and the reflected radiation scattered by the lung as a spectral response to the presence of water in the lung is measured. The reflected radiation is compared with calibrated values to evaluate an occurrence of pulmonary edema. The non-invasive method disclosed in U.S. Pat. No. 6,332,091 requires the use of external equipment, consequently pulmonary edema may only be detected in a patient at locations where such equipment is present.
In U.S. Pat. No. 7,010,337, a sensor for measuring transmission or reflection of light by the blood is described. The sensor is placed adjacent the aorta of a patient to evaluate the oxygen saturation of the blood passing in the aorta. Detection of edema is not discussed in U.S. Pat. No. 7,010,337.
In U.S. Pat. No. 6,409,675, a implantable monitor with one or more sensors configured for extravascular placement is described. The extravascular sensors include sensors for vascular plethysmography, heart and lung sounds, thoracic impedance, and EKG. For example, optical sensors adapted to determine arterial blood oxygen and arteriolar volume, and sound sensors adapted to detect pulmonary edema are disclosed. As alternate embodiments, detection of pulmonary edema utilizing thoracic impedance, ultrasound or analysis of Cheyne-Stokes respiration are disclosed.
Consequently, there remains a need within the art for an implantable medical system and a method using such system that are capable of detecting the occurrence of edema at an early stage, i.e. incipient edema. | {
"pile_set_name": "USPTO Backgrounds"
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The development in the 1990s of a high-brightness blue-light-emitting LED made possible the introduction of commercial high-efficiency, white-light-emitting LEDs that are usable in general lighting applications. The realization of white light from these monochromatic blue LEDs is achieved by employing phosphors which convert at least a portion of the shorter-wavelength blue light into longer green, yellow and red wavelengths. One phosphor system of considerable interest for such phosphor-conversion LEDs (pc-LEDs) is based on the family of cerium-activated garnets represented by the general formula A3B5O12:Ce, wherein A is Y, Sc, La, Gd, Lu, or Tb and B is Sc, Al or Ga. These garnet-based phosphors have a cubic lattice structure and absorb wavelengths in the range from 420 nm to 490 nm which means that they are excitable by radiation from a blue light source such as a blue LED. Other garnet phosphors such as (Y, La, Gd)Na2Mg2V3O12:Eu, Bi and Ca3Sc2Si3O12:Mg,Ce are also of interest for pc-LEDs because of their red-light emissions which may be used to improve the color rendering index (CRI) of white-emitting pc-LEDs.
Of the garnet phosphors, cerium-activated yttrium aluminum garnet, Y3Al5O12:Ce, (YAG:Ce), has seen widespread use in commercial white-emitting pc-LEDs. The YAG:Ce phosphor has been shown to be a very efficient converter for blue wavelengths generating a broad intense yellow emission band centered at about 575 nm. This intense yellow emission and the remaining unconverted blue light emitted by the LED combine to form a white light emission.
One drawback to using the YAG:Ce phosphor by itself in a pc-LED is that the white emission from the pc-LED has a high color temperature and relatively low color rendering index (CRI). One way to produce a warmer white light and increase CRI is to add a red-emitting phosphor. However, phosphor mixtures tend to have reduced efficacy because the phosphors interfere with one another due to energy transfer via overlapping emission and absorption as well as non-radiative processes. Another way to adjust the emission of the pc-LED is to change the elemental composition of the phosphor to increase output in the desired wavelength range. Unfortunately, this can also affect the efficiency of the phosphor, resulting in a lower efficacy LED.
Phosphor-conversion LEDs can also be used to produce single-color LEDs by fully converting blue or UV light emitted by an LED into another color such as green or red. This is desirable in some cases because the pc-LED efficacy is greater than that of the comparable monochromatic direct semiconductor LED. However, the range of colors that can be produced by full conversion is similarly limited by the ability to manipulate the composition of available phosphors.
Thus it would be an advantage for both white and single-color pc-LEDs to be able to adjust the emission colors of available garnet-based phosphors without having to change their composition. | {
"pile_set_name": "USPTO Backgrounds"
} |
The present invention relates, in general, to a test fixture for high speed and power TAB (Automated Bonding) type semiconductor circuits or devices.
TAB circuits or devices are formed by attaching a semiconductor circuit die to a supporting film having a plurality of conductor leads etched thereon. The film contains sprocket holes similar to those found on a reel of 35 mm film. The circuit dies or devices are centrally located on the film, and are mechanically and electrically secured to the etched conductor leads which fan out to bonding pads along the outside edges of the film.
The testing of semiconductor circuits in TAB type form presents a combination of formidable engineering problems. Each of the circuits tested must be subjected to a wide range of temperatures to insure that they will operate properly over their full specified range. In addition, electrical connections and controlled impedance paths to each of the circuits must be provided so that all of their functions can be properly tested.
The present invention seeks to provide a test fixture which meets these criteria. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The invention relates to a method of fabricating a thin-film semiconductor device and an apparatus for fabricating the same, and more particularly to a method of forming a thin silicon film used for a crystalline silicon thin-film transistor, and an interface between semiconductor and an insulating film, used for a field effect transistor, and further to an apparatus of fabricating such a thin silicon film and such an interface.
2. Description of the Related Art
Japanese Patent Publication No. 7-118443 has suggested a method including the step of radiating laser beam having a short wavelength, to an amorphous silicon thin film formed on an amorphous substrate, to thereby fabricate a thin film transistor. The method makes it possible to crystallize amorphous silicon without wholly heating the substrate, and hence, makes it possible to fabricate a semiconductor device or a semiconductor integrated circuit on a substrate having a wide area such as a substrate to be used for a liquid crystal display, or a cheap substrate such as glass.
Japanese Unexamined Patent Publication No. 9-320961 has suggested a method of fabricating a thin-film transistor. In this method, the steps of forming an amorphous silicon thin film to which laser beam is to be radiated, radiating laser beam to the amorphous silicon thin film, carrying out hydrogenation in plasma, and forming a gate insulating film are carried out in this sequence or other sequences without exposure to atmosphere.
The Publication also discloses an apparatus of fabricating a semiconductor thin film, including a first chamber in which a substrate is loaded in vacuum, a second chamber in which silicon is formed, a third chamber in which laser beam is radiated, a fourth chamber in which an insulating film is formed, a fifth chamber in which annealing is carried out in hydrogen atmosphere, a sixth chamber in which a substrate is unloaded, and a seventh chamber through which a substrate is transferred to other chambers.
A glass substrate is transferred into the apparatus from the first chamber. The glass substrate can be transferred to any one of the chambers through the seventh chamber and a vacuum valve. The first to seventh chambers are equipped with a gas exhaust system independently of one another, and hence, can exhaust reactive gas, inert gas and other gases introduced from gas introducers in the steps of forming a silicon film, forming an insulating film, and annealing.
When a substrate is transferred out of any one of the chambers, the chamber is sufficiently exhausted. When the chamber has almost the same pressure as that of the seventh chamber, a vacuum valve is released, and then, a substrate is taken out of the chamber by means of a robot. Then, the vacuum valve is closed.
The substrate is introduced into a next chamber having almost the same vacuum degree as that of the seventh chamber after releasing a vacuum valve, transferring the substrate into the third chamber, and closing the vacuum valve. After closing the vacuum valve, a process gas is introduced into the chamber, and a pressure and a temperature in the chamber are adjusted to a predetermined pressure and temperature. Then, laser beam is radiated to the substrate.
The substrate is transferred among the first to sixth chambers in such a manner as mentioned above. A plurality of substrates can be transferred among the chambers through the use of a plurality of robots, in which case, the chambers are sufficiently exhausted. A vacuum valve may be released and closed, and the substrate may be transferred after the chambers are caused to have almost the same pressure in inert gas, nitrogen gas or hydrogen gas atmosphere.
The substrate is transferred between the first chamber and atmosphere and further between the sixth chamber and atmosphere, after nitrogen or inert gas is leaked with the vacuum valve being closed, and a valve is released to thereby allow the first and sixth chambers to be in fluid communication with atmosphere.
Thus, all the steps are carried out without exposure to atmosphere. The reason is as follows. Since a surface of silicon formed by laser crystallization is quite active, contaminants are likely to be adhered to the surface, if the silicon is exposed to atmosphere. This results in degradation in performances of resultant TFT. As an alternative, there is dispersion among performances of TFT. In order to avoid such degradation or dispersion, all the steps are carried out without exposure to atmosphere.
The inventor conducted the experiment in which excimer laser crystallization and formation of a silicon dioxide film were carried out in the same apparatus in two cases in one of which a substrate was exposed to atmosphere and in the other of which a substrate was not exposed to atmosphere. Herein, xe2x80x9cthe same apparatusxe2x80x9d includes a case in which a substrate is transferred to another apparatus without exposure to atmosphere. In the case in which a substrate was not exposed to atmosphere, a fabrication yield was much enhanced because dusts and particles were prevented from adhering to a product. However, it was also found out that such enhancement in a fabrication yield can be obtained by enhancing cleanness in a clean room. A fabrication yield was enhanced best in an film-forming apparatus including a washing device therein.
Comparing a trap level density in a silicon film to an interface level density (or density of electric charge in a fixed oxide film), the trap level density is obviously greater than the interface level density. That is, there is a problem of insufficiency in performances of a silicon film (or a trap level density) in order to have sufficient cleanness in a product having a silicon film and a gate insulating film both formed without exposure to atmosphere in the same apparatus.
The inventor analyzed the above-mentioned problem, and resultingly, found out the following problems in connection with steps of fabricating a silicon film and a gate insulating film and an apparatus of fabricating the same.
The first problem is as follows. For instance, in a cluster tool type apparatus suggested in Japanese Unexamined Patent Publication No. 7-99321, a plurality of chambers is arranged having its own purpose. Hence, it is quite difficult to keep a chamber located at a core, away from contaminants. There occurs cross-contamination in transfer of a substrate between chambers, even though the cross-contamination is slight.
The second problem is as follows. For instance, an in-line type apparatus suggested in Japanese Unexamined Patent Publication No. 5-182923 is accompanied with a problem that it is unavoidable generation of minute dust, in particular, metal particles due to a great frictional area between parts in vacuum.
The third problem is as follows. Silicon crystallized by laser beam would have a quite active surface. For instance, if silicon is coated with active species having energy, for instance, radical species such as hydrogen radical, oxygen radical, hydrogen ion, oxygen ion, ion species or ozone, after the silicon has been crystallized by laser beam, but before a gate insulating film is formed, contaminants adhered to a wall of a chamber and metal constituting a wall of a chamber are excited, resulting in that atmosphere in which a substrate is put is contaminated.
The fourth problem is that since laser radiation in oxidation atmosphere reflects dispersion in laser intensity in a step of introducing oxygen into silicon, there would be dispersion in a concentration of oxygen in a silicon film. This results in non-uniformity in characteristics of resultant silicon films.
The fifth problem is as follows. When a plurality of steps are to be successively carried out without exposure to atmosphere, for instance, steps of crystallizing a silicon film by means of laser beam and thereafter forming a gate insulating film, though it is possible to reduce contaminants adhered to the silicon film by not exposing the silicon film to atmosphere, the above-mentioned problems still interfere with fabrication of a semiconductor device. A conventional method of fabricating a semiconductor device such as LSI includes a step of carrying out thermal oxidation at about 1000 degrees centigrade to form an interface in a crystalline silicon film. This means that it is necessary to control contaminants even in a vacuum apparatus.
There has been suggested remote plasma chemical vapor deposition (CVD) to reduce damage caused by plasma and form a qualified gate insulating film. For instance, Japanese Unexamined Patent Publication No. 5-21393 has suggested a plasma CVD apparatus including a first chamber in which plasma is generated and a second chamber in which a substrate is processed. The first chamber is separate from the second chamber. It is considered that the suggested apparatus would accomplish a low density of electric charge of a fixed oxide film in the range of 1xc3x971011 to 1xc3x971012cmxe2x88x922, and a low interface level density smaller than 6xc3x971010cmxe2x88x922 eVxe2x88x922. However, this advantage of accomplishing such low densities is restricted to performances of a silicon film.
The sixth problem is as follows. A chamber in which a substrate is processed is frequently caused to have a high vacuum degree or a low pressure in order to prevent contaminants from adhering to a surface of a substrate. In particular, in plasma CVD where a film is to be formed at a pressure smaller than atmospheric pressure, a chamber is exhausted almost to an ultimate vacuum degree except while a film is being formed. For the same reason, a chamber through which a substrate is transferred to another chambers, in a batch-type apparatus, is exhausted almost to and kept at an ultimate vacuum degree.
In an excimer laser radiation apparatus, excimer laser beam is often radiated in vacuum atmosphere. However, silicon particles separated from a silicon film during laser radiation are adhered to a window through which laser beam is introduced into the apparatus, resulting in reduction in a laser transmission rate with the lapse of time.
In order to solve this problem, Japanese Unexamined Patent Publication No. 9-139356 has suggested a laser annealing apparatus in which excimer laser beam is focused on a window to which silicon is adhered, to thereby thermally decompose silicon. However, in this apparatus, since a laser beam which is usually focused on a surface of a substrate is focused on a surface of the window having a different optical length, it would be absolutely necessary to rearrange optical systems. When there are employed optical systems having a small focal length, in particular, when mask projection method is carried out, it is necessary to accurately position optical systems, resulting in reduction in an operation efficiency of the apparatus.
Japanese Unexamined Patent Publication No. 3-292719 has suggested a method of forming a silicon semiconductor layer, including the steps of forming a silicon semiconductor layer on an insulating substrate at a temperature equal to or lower than 600 degrees centigrade, and radiating energy beam to the silicon semiconductor layer to thereby turn the silicon semiconductor layer into polysilicon.
Japanese Unexamined Patent Publication No. 9-36376 has suggested a method of fabricating a thin-film semiconductor device, including the steps of forming a thin semiconductor film on an insulating substrate, the thin semiconductor film containing hydrogen at 10% or greater as well as inert impurities, annealing the insulating substrate at 350 degrees centigrade or higher to thereby remove hydrogen such that the thin semiconductor film contains hydrogen at 10% or smaller, and radiating laser beam to the thin semiconductor film to thereby activate the impurities.
Japanese Unexamined Patent Publication No. 5-326397 has suggested a method of fabricating a semiconductor device, including the steps of forming an amorphous semiconductor film on a semiconductor substrate at such a temperature that the amorphous semiconductor film has a planar surface at a pressure smaller than an atmospheric pressure, annealing the semiconductor substrate in inert gas atmosphere at a temperature higher than a temperature at which the amorphous semiconductor film is formed, to thereby turn the amorphous semiconductor film into a polysilicon film having irregularities at a surface thereof, the polysilicon film acting as a first electrode of a capacitor, forming a dielectric film on the first electrode, and forming a second electrode on the dielectric film.
Japanese Unexamined Patent Publication No. 5-182919 has suggested a method of fabricating a thin polysilicon film, including the steps of forming an amorphous silicon film on a glass substrate by LPCVD, putting the substrate in an oxygen atmosphere to thereby oxidize a surface of the amorphous silicon film, and annealing the amorphous silicon film in inert gas atmosphere at 600 degrees centigrade or smaller to thereby turn the amorphous silicon film into polysilicon.
Japanese Unexamined Patent Publication No. 11-17185 has suggested a method of fabricating a liquid crystal display device, including the steps of forming a semiconductor film almost all over a substrate to define an insulating gate type transistor, heating and recrystallizing the semiconductor film, forming a gate insulating film of the insulating gate type transistor on the thus recrysallized semiconductor film, and forming a gate electrode of the insulating gate type transistor almost all over the gate insulating film. All of the steps are carried out in an apparatus which is kept vacuous.
Japanese Unexamined Patent Publication No. 10-149984 has suggested a method of forming polysilicon, including the steps of radiating laser beam to an amorphous silicon film formed on a substrate, in a hermetically sealed chamber, and annealing the amorphous silicon film to thereby turn the film into polysilicon. The chamber is designed to have a vacuum degree of 0.1 Torr or higher, and have atmosphere of at least one of hydrogen, nitrogen and inert gas.
Japanese Unexamined Patent Publication No. 10-116989 has suggested a method of fabricating a thin-film transistor, including the steps of forming a semiconductor film on a substrate without exposure to atmosphere, crystallizing the semiconductor film in non-oxidizing atmosphere without exposure of the substrate to atmosphere, forming a first gate insulating film on the semiconductor film without exposure of the substrate to atmosphere, annealing the first gate insulating film and the semiconductor film, patterning the first gate insulating film and the semiconductor film, hydrogenating the substrate, and forming a second gate insulating film on the first gate insulating film.
Japanese Unexamined Patent Publication No. 9-17729 has suggested a method of fabricating a semiconductor device, including the steps of forming a first insulating film, a thin amorphous semiconductor film, and a second insulating film on an upper surface of an insulating substrate without exposure to atmosphere, and radiating laser beam through a lower surface of the insulating substrate to thereby turn the thin amorphous semiconductor film into crystal.
Japanese Unexamined Patent Publication No. 9-7911 has suggested an apparatus for fabricating a semiconductor device, including (a) a laser annealing unit having a chamber in which a substrate is kept hermetically sealed, and in which laser beam is radiated to the substrate, (b) a film-forming unit having a chamber in which a substrate is kept hermetically sealed, and in which a thin film is formed on the substrate, and (c) a transfer unit which transfers the substrate between the chambers with the substrate being kept hermetically sealed.
In view of the above-mentioned problems, it is an object of the present invention to provide a method and an apparatus both of which is capable of fabricating a thin silicon film having a low trap level density, by radiating laser beam thereto.
It is also an object of the present invention to provide a method and an apparatus both of which are capable of providing an interface between semiconductor and an insulating film which interface has a small interface level density, that is, a field effect transistor having improved characteristics.
Another object of the present invention is to provide a method and an apparatus both of which are capable of forming the above-mentioned thin silicon film at a temperature in the range of room temperature to 600 degrees centigrade for the purpose of allowing to use a cheap glass substrate.
In one aspect of the present invention, there is provided a method of fabricating a thin-film semiconductor device, comprising the steps of (a) melting and recrystallizing at least a surface of a thin semiconductor film formed on a substrate, in a pressure lower than an atmospheric pressure or in inert gas atmosphere, (b) keeping the substrate in atmosphere including oxygen gas, and (c) forming an insulating film on the thin semiconductor film with the substrate being kept in a pressure lower than an atmospheric pressure or inert gas atmosphere.
It is preferable that the atmosphere predominantly includes oxygen gas or the atmosphere includes only oxygen gas.
It is know that if silicon is left in atmosphere, there would be formed a natural oxidation film on an active surface of silicon. Since organic substances and/or metal particles floating in the air are absorbed into the natural oxidation film, the natural oxidation film formed in atmosphere is not suitable for formation of a clean interface, which is an object of the present invention.
In a conventional method of fabricating a bipolar transistor, in order to form silicon crystal by epitaxial growth, the following steps are carried out: removing a natural oxidation film through the use of hydrofluoric acid, forming a chemical oxide film through the use of heated solution of ammonia/H2O2/H2O or HCl/H2O2/H2O, annealing at 1000 degrees centigrade or greater in an epitaxial growth furnace through the use of hydrogen gas, to thereby remove the chemical oxide film and resultingly form a clean surface of silicon, and growing a film.
However, when a step which is to be carried out at a temperature in the range of room temperature to 600 degrees centigrade has to be carried out, the high-temperature step in the above-mentioned conventional method can not be selected.
In addition, since a surface of a thin silicon film having been crystallized by laser beams has experienced a temperature of 1000 degrees centigrade or higher at which silicon would be molten, even in an order of nanoseconds, the surface is in quite active condition. Hence, even in a vacuous chamber, contaminants would be readily adhered to the surface, if atmosphere in the chamber is suitably controlled.
In contrast, in accordance with the present invention, highly purified oxygen gas is introduced into a chamber just after silicon has been crystallized by laser beams, to thereby form a natural oxidation film having a low concentration of contaminants. By forming such a natural oxidation film on a surface of silicon, it would be possible to prevent contaminants from being adhered to a surface of silicon in various chambers such as a chamber in which laser beam is radiated, a chamber through which a substrate is transferred to another chamber, or a chamber in which a film is formed.
If active gases such as radicals or ions are used for formation of a natural oxidation film, it would be possible to effectively form a natural oxidation film and establish hydrogen passivation. However, the use of those active gases might cause absorption of contaminants adhered to a wall of a chamber into a natural oxidation film, and thus, it is not preferable to use such active gases.
The inventor conducted the experience in which silicon dioxide films were formed on a silicon wafer through the use of oxygen gases A, B and C having different purities, and then, leakage current was measured for each one of oxygen gases A, B and C.
There were obtained current densities X1, X2 and X3, when an electric field of 5 MV/cm was applied to the samples in which the gases A, B and C were used, respectively. The relation among X1, X2 and X3 is X1 greater than X2 greater than X3.
Since carbon existing in a silicon dioxide film would cause current leakage, it is necessary to reduce a concentration of carbon. In addition, since metals such as Na, K or Li exist as movable ions in an oxide film, they would cause a threshold value to shift. Accordingly, gas having a high purity, such as O2, N2O, silane or disilane is necessary to be prepared for formation of a thin silicon film, oxidation of a surface of silicon or deposition of a silicon dioxide film.
Oxygen gas is fractionated from air through low temperature processing. In fractionation, hydrocarbon such as methane is all residual in oxygen gas because a boiling point of methane is higher than a boiling point of oxygen. Specifically, a boiling point of oxygen is xe2x88x92183 degrees centigrade, a boiling point of methane is xe2x88x92162 degrees centigrade, and a boiling point of nitrogen is xe2x88x92196 degrees centigrade. As a result, hydrocarbon in the air is condensed and residual in oxygen gas.
The following method is carried out in order to remove such hydrocarbon. First, porous catalyst such as Pt or Pd is heated. Then, hydrocarbon is made to react with oxygen to thereby form CO2 and H2O. Those CO2 and H2O are absorbed into an absorber. As a result, it is possible to reduce a concentration of hydrocarbon in oxygen to 0.1 ppm or smaller, and concentrations of CO2 and CO to 0.1 ppm or smaller. Hence, an apparatus for refining oxygen may be arranged upstream of a gas supplier which supplies gases to a process apparatus.
It is known that argon and nitrogen are residual in a step of fractionation. However, highly purified argon or highly purified nitrogen in an order of ppm does not cause any problems in the present invention. For instance, even if hydrogen, nitrogen or inert gas such as argon each having a purity of 99.9999% or higher is mixed with oxygen gas, such mixture gas does not cause nay problems.
As a result of the experiments the inventor conducted, the following was found out.
It is preferable that the atmosphere includes oxygen gas having purity of 99.999% or greater.
It is preferable that the atmosphere further includes hydrogen gas. having purity of 99.999% or greater.
It is preferable that the atmosphere further includes nitrogen gas having purity of 99.999% or greater.
It is preferable that the atmosphere further includes inert gas having purity of 99.999% or greater.
It is preferable that a process gas used for forming the insulating film has purity of 99.999% or greater.
It is preferable that a process gas used in the method includes hydrocarbon (CnHm) species having a total concentration of 1 ppm or smaller.
It is preferable that recrystallization in the step (a) is carried out through laser radiation.
There is further provided a method of fabricating a thin-film semiconductor device, including the steps, in sequence, of (a) introducing a substrate into a vacuous chamber, (b) introducing non-reactive gas into the chamber, (c) radiating laser beam to the substrate in the chamber, (d) introducing oxygen gas into the chamber, (e) exhausting the non-reactive gas and the oxygen gas until a pressure in the chamber is reduced down to a predetermined pressure, and (f) taking the substrate out of the chamber.
It is preferable that the non-reactive gas is selected from the group consisting of nitrogen gas, inert gas and hydrogen gas alone or in combination.
It is preferable that the method further includes the step (g) of radiating laser beam to a window through which laser beam is radiated into the chamber such that laser beam is not radiated to a completed region of the substrate, the step (g) being to be carried out between the steps (d) and (e).
It is preferable that the non-reactive gas is kept introduced into the chamber to cause the non-reactive gas to have a constant pressure.
It is preferable that the method further includes the step of heating the substrate.
There is still further provided a method of fabricating a thin-film semiconductor device, including the steps, in sequence, of (a) introducing a substrate into a vacuous chamber, (b) introducing non-reactive gas into the chamber, (c) radiating laser beam to the substrate in the chamber, (d) stopping introduction of the non-reactive gas into the chamber, (e) introducing oxygen gas into the chamber, (f) transferring the substrate from the chamber into a second chamber having the same internal pressure as that of the chamber.
It is preferable that the method further includes the steps of (g) radiating laser beam to a window through which laser beam is radiated into the chamber such that laser beam is not radiated to a completed region of the substrate, after the substrate has been transferred into the second chamber, and (h) exhausting the non-reactive gas and the oxygen gas until a pressure in the chamber is reduced down to a predetermined pressure.
In another aspect of the present invention, there is provided an apparatus for fabricating a thin-film semiconductor device, including (a) a first chamber which is capable of keeping the first chamber in various pressure atmospheres, (b) an energy beam radiator which radiates energy beam to at least a surface of a semiconductor thin film formed on a substrate, (c) a carrier which carries the substrate between the first chamber and a second chamber which is capable of accomplishing the same pressure atmosphere as that of the first chamber, (d) a first gas-introducer which introduces nitrogen gas or inert gas into the first chamber, (e) a gas pressure regulator which keeps the first and second chambers in a predetermined pressure atmosphere, (f) a second gas-introducer which introduces oxygen gas into the first chamber, and (g) a controller which controls operation of the energy beam radiator, the carrier, the first gas-introducer, the gas pressure regulator, and the second gas-introducer.
It is preferable that the controller controls operation of the energy beam radiator, the carrier, the first gas-introducer, the gas pressure regulator, and the second gas-introducer such that the following steps are carried out in this sequence: (a) adjusting pressures in the first and second chambers so that the pressures are almost equal to each other, (b) introducing the substrate into the first chamber from the second chamber, (c) introducing the nitrogen gas or inert gas into the first chamber, (d) radiating laser beam to the semiconductor thin film, and (e) introducing oxygen gas into the first chamber.
It is preferable that the apparatus further includes a heater for heating the substrate.
It is preferable that the controller controls the laser beam radiator such that laser beam is radiated to the first chamber without radiating laser beam to a completed region of the substrate, after the oxygen gas has been introduced into the first chamber.
In order to successively carry out a step in which laser is radiated at a pressure almost equal to atmospheric pressure, a step of carrying out CVD at a vacuum degree of a couple of Torrs, and a step of transferring a substrate between those steps without exposure of the substrate to atmosphere, it is preferable to reduce a difference in a pressure between chambers between which the substrate is transferred.
After laser beam has been radiated in nitrogen or inert gas atmosphere, but before nitrogen or inert gas is compulsively exhausted, oxygen gas is introduced into a chamber in which a laser beam is radiated, to thereby oxidize an active surface of silicon. At this time, silicon adhered to a window through which laser beam is introduced into the chamber is also oxidized, because silicon has an active surface. With oxygen being introduced into the chamber, the laser beam is introduced into the chamber such that the laser beam is not radiated to effective areas.
In particular, when ultra-violet ray is used as a laser beam, oxygen gas is decomposed by the ultra-violet ray, and at the same time, silicon having been adhered to the window and having not been oxidized by oxygen gas is heated. The thus decomposed, active oxygen reacts with the thus heated silicon to thereby form silicon dioxide, ensuring that reduction in a transmission rate of the laser beam is prevented.
The above-mentioned steps are carried out either in a condition in which the gas is sealed in the chamber or in a condition in which the gas is allowed to flow with the pressure being kept constant.
Then, the substrate is transferred from the chamber in which a laser beam is radiated to the substrate to a second chamber through which the substrate is transferred to another chamber. When the substrate is transferred in a vacuum condition, nitrogen or inert gas is stopped to be supplied into the chamber concurrently with stopping of introduction of oxygen gas and stopping of radiation of the laser beam, to thereby much exhaust the gas.
After it has been confirmed that the chambers are in almost the same pressure atmosphere, a gate valve separating the chambers is made open, and the substrate is transferred from the previous chamber to the second chamber.
When the substrate is transferred in oxygen atmosphere, the second chamber is caused to have a predetermined pressure in advance by inert gas, nitrogen gas or oxygen gas all having a high purity, alone or in combination. Then, the chamber in which the laser beam is radiated is caused to be in oxygen atmosphere, and the chamber is caused to have the same pressure as that of the second chamber. Thereafter, the gate valve separating the chambers from each other is made open, and the substrate is transferred to the second chamber.
Thus, it would be possible to prevent contaminants such as metal or carbon from adhering to a surface of a silicon film formed on a substrate, and prevent reduction in a transmission rate of laser beam through a laser-introducing window. | {
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In addition to NAND-type flash memory, NOR-type flash memory, and the like, AG-AND-type flash memory, in which an assist gate is arranged adjacent to a floating gate, has been widely used as memory of portable equipment such as a digital camera.
FIG. 5 shows a conceptual configuration of AG-AND-type flash memory (hereinafter simply called AG-AND flash memory). A single block is formed from a plurality of pages (two pages), each of which is a unit for reading and writing data (each page is formed from a plurality of sectors), and a single cluster is formed from a plurality of blocks (four blocks). Reading and writing of data can be executed on a per-page basis, and deletion of data can be executed on a per-block basis. The AG-AND flash memory has a plurality of banks (e.g., four banks). The banks can be subjected to parallel processing access, and access can be made simultaneously to the banks.
Each of the pages is formatted into a data area and a control area. The control area stores address information, a physical-logical address correspondence table, generation information, and management information about presence/absence of an invalid flag, all of which pertain to all blocks belonging to a certain cluster in the control area. The reason for this is that, in AND-type flash memory, the physical-logical address correspondence table includes a maximum of several percentages of unavailable areas. An invalid flag in the unavailable area must be set to make a logical address such that a physical address of that area is not used. For instance, the physical-logical address correspondence table is a table where, when a physical address 0002h is unavailable, the next physical address 0003h is taken as a logical address 0002h.
As shown in FIG. 6, when all blocks belonging to a certain cluster exist across a plurality of banks (bank 0, bank 1, bank 2, and bank 3), management information 100 about the cluster is stored in a specific location (a control area) of a specific page (the first page) of a leading bank (bank 0). When data are read from a certain cluster, access is first made to bank 0, to thus read management information and acquire address information about all the blocks belonging to the cluster. In accordance with the thus-acquired address information, reading is performed simultaneously in relation to all the banks, whereby data are acquired.
Upon start-up of portable equipment such as a digital camera or the like, management information about all clusters must be read and acquired. However, according to a conventional reading scheme, reading management information about all clusters entails consumption of much time, thereby contributing to an increase in the time required to initialize a system.
Conventionally, as shown in FIG. 6, the management information about a cluster is stored in a specific page of a leading bank (bank 0), and in a single operation only one page from a certain bank can be read. For this reason, management information about cluster 0 is read through first reading operation; management information about cluster 1 is read through second reading operation; and management information about cluster 2 is read through third reading operation. Thus, reading operations must be performed in equal number to the clusters, thereby raising a problem of an increase in processing time as the number of clusters increases.
The present invention provides a device capable of quickly reading data such as management information about clusters. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to magneto-optic films, methods of preparing same and devices incorporating such films.
2. Description of the Prior Art
Magneto-optic films and/or various devices utilizing same have been described in the following patents, the teaching of which is incorporated herein by reference thereto: U.S. Pat. Nos. 4,500,173 and 4,500,177, directed to spatial light modulators. U.S. Pat. Nos. 4,625,167 and 4,755,752, directed to crack detection devices; U.S. Pat. No. 4,728,178, directed to switches, modulators; U.S. Pat. No. 4,604,577, directed to magnetic field sensors; and, U.S. Pat. Nos. 3,838,450; 3,989,352 and 4,608,742, directed to memory and recording/modulator devices. Magneto-optic films have also been used in optical isolators, see e.g., Fujitsu Science & Tech. Journal, Vo. 26, No. 26. Such films may also find utility in rotation sensors for brakes.
One of the drawbacks of monocrystalline ferrimagnetic oxide films has been the low coercivity (less than 1 Oe) of such films. See, e.g., Hansen et al. "Media for Erasable Magneto-optic Recording" IEEff Trans. Mag., Volume 25, pp. 4390-4404. . As an alternative to the low coercivity monocrystalline ferrimagnetic films the art has produced ferrimagnetic polycrystalline films. Such magneto-opt films have been prepared utilizing sputtering, vapor deposition or spray pyrolysis. However, such polycrystalline films have coercivity values of 200-2,000 Oe. These values are too high for the applications which the films of the present invention find utility, because of the high switch fields required.
The herein invention resides in the discovery that monocrystalline ferrimagnetic oxide films having good square shaped hysteresis loops of predetermined coercivity can be produced by imparting to such films defects of controlled size, number, and distribution. The present invention enables replicable production of monocrystalline ferrimagnetic oxide films which operate at low switch fields, The present invention now allows retention of the desirable properties of monocrystalline ferrimagnetic oxide films while modifying the low coercivity levels characteristic to such materials and providing a readily switchable film having a good square shaped hysteresis loop. | {
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} |
There are many types of devices comprising two or more subcompartments that are separated from each other by septa like, for example, monofilament screens, membranes, gels, filters, and fritted discs. Generally, these devices are assembled from a plurality of essentially parallel frames or spacers, separated from each other by the septa. Some of these devices comprise a repetitive assembly of functional units requiring only two compartments, such as a repetitive assembly of input and output subcompartments in a filter press.
The invention is of particular relevance to electrophoretic devices where three or more subcompartments are aligned, and wherein transport of solutes potentially occurs across all the compartments. For instance, in U.S. Pat. No. 4,362,612 issued to Bier, the adjoining compartments are functionally designed to electrophoretically adjust to different pH values, thereby separating dissolved proteins according to their isoelectric points. Similar multiple subcompartments devices are described in U.S. Pat. No. 4,971,670 issued to Faupel et al., U.S. Pat. No. 5,173,164 issued to Egen et al., U.S. Pat. No. 4,963,236 issued to Rodkey et al., and U.S. Pat. No. 5,087,338 issued to Perry et al.
All of the above patents disclose devices comprising a series of parallel spacers that are separated from each other by septa, which results in an essentially parallel array of subcompartments. Apart from the cited patents, numerous other such devices have been disclosed in patents and other publications. In all such devices, electrodes are provided at the ends of the assembly of subcompartments for the application of an electrical field.
Each subcompartment of these devices usually includes an input port and an output port for circulation of process fluid. The septa have a primary function of streamlining the flow of liquid without unduly hindering the intercompartmental transport of solutes due to electrical or diffusional forces. The septa in these devices may also have other functions, depending on the intended use of the apparatus. In some instruments, like the above-identified Bier and Egen et al. devices, the septa are simply monofilament screens of fine porosity, and the relatively open nature of the septa are used to minimize interaction with the electric process. In the Faupel et al. device, on the other hand, the septa constitute buffered membranes of polyacrylamide gels impregnated on fiber-glass filters. The intended purpose of the buffered septa is to control the transport of proteins across the membranes, limiting this transport to only proteins of certain polarity. In yet other devices (Perry et al., for instance) membranes of controlled porosity are used to separate solutes according to particle size. In the present application, the generic term septum is utilized to describe all of the above possibilities, as these are all compatible with the invention at hand. In addition to such inter-compartment septa, most instruments require physical containment of electrolytes used around the electrodes, for which the term membrane will be used.
The production, assembly and use of such devices is complicated and made difficult by the multitude of component spacers and septa, all of which have to be assembled in a parallel sequence and sealed against fluid leaks. | {
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The throughput of many conventional orthogonal frequency division multiplexed (OFDM) systems has been limited by the communication capacity of the individual channels. To achieve higher throughput, multiple antennas may be used to communicate additional data without an increase in frequency bandwidth. One problem with employing multiple antenna devices is that at least some of their communications should be compatible with legacy communication devices that use single antennas. | {
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Heat-softenable toners are widely used in imaging methods such as electrostatography, wherein electrically charged toner is deposited imagewise on a dielectric or photoconductive element bearing an electrostatic latent image. Most often in such methods, the toner is then transferred to a surface of another substrate, such as, e.g., a receiver sheet comprising paper or a transparent film, where it is then fixed in place to yield the final desired toner image.
When heat-softenable toners, comprising, e.g., thermoplastic polymeric binders, are employed, the usual method of fixing the toner in place involves applying heat to the toner once it is on the receiver sheet surface to soften it and then allowing or causing the toner to cool.
One such well-known fusing method comprises passing the toner-bearing receiver sheet through the nip formed by a pair of opposing rolls, at least one of which (usually referred to as a fuser roll) is heated and contacts the toner-bearing surface of the receiver sheet in order to heat and soften the toner. The other roll (usually referred to as a pressure roll) serves to press the receiver sheet into contact with the fuser roll. In some other fusing methods, the configuration is varied and the "fuser roll" or "pressure roll" takes the form of a flat plate or belt. The description herein, while generally directed to a generally cylindrical fuser roll in combination with a generally cylindrical pressure roll, is not limited to fusing systems having members with those configurations. For that reason, the term "fuser member" is generally used herein in place of "fuser roll" and the term "pressure member" in place of "pressure roll".
The fuser member usually comprises a rigid core covered with a resilient material, which will be referred to herein as a "base cushion layer." The resilient base cushion layer and the amount of pressure exerted by the pressure member serve to establish the area of contact of the fuser member with the toner-bearing surface of the receiver sheet as it passes through the nip of the fuser member and pressure members. The size of this area of contact helps to establish the length of time that any given portion of the toner image will be in contact with and heated by the fuser member. The degree of hardness (often referred to as "storage modulus") and stability thereof, of the base cushion layer are important factors in establishing and maintaining the desired area of contact.
In some previous fusing systems, it has been advantageous to vary the pressure exerted by the pressure member against the receiver sheet and fuser member. This variation in pressure can be provided, for example in a fusing system having a pressure roll and a fuser roll, by slightly modifying the shape of the pressure roll. The variance of pressure, in the form of a gradient of pressure that changes along the direction through the nip that is parallel to the axes of the rolls, can be established, for example, by continuously varying the overall diameter of the pressure roll along the direction of its axis such that the diameter is smallest at the midpoint of the axis and largest at the ends of the axis, in order to give the pressure roll a sort of "bow tie" or "hourglass" shape. This will cause the pair of rolls to exert more pressure on the receiver sheet in the nip in the areas near the ends of the rolls than in the area about the midpoint of the rolls. This gradient of pressure helps to prevent wrinkles and cockle in the receiver sheet as it passes through the nip. Over time, however, the fuser roll begins to permanently deform to conform to the shape of the pressure roll and the gradient of pressure is reduced or lost, along with its attendant benefits. It has been found that permanent deformation (alternatively referred to as "creep") of the base cushion layer of the fuser member is the greatest contributor to this problem.
One type of material that has been widely employed in the past to form a resilient base cushion layer for fuser rolls is condensation-crosslinked poly(dimethylsiloxane) elastomer. "Poly(dimethyl-siloxane)" will sometimes be alternatively referred to herein as "PDMS". The prior art has also taught or suggested that various fillers comprising inorganic particulate materials can be included in such PDMS base cushion layers to improve their mechanical strength and/or thermal conductivity. Higher thermal conductivity is advantageous when the fuser roll is heated by an internal heater, so that the heat can be efficiently and quickly transmitted toward the outer surface of the fuser roll and toward the toner on the receiver sheet it is intended to contact and fuse. Higher thermal conductivity is not so important when the roll is intended to be heated by an external heat source. Disclosure of such filled condensation-cured PDMS elastomers for fuser rolls can be found, for example, in U.S. Pat. Nos, 4,373,239; 4,430,406; and 4,518,655.
Optimal metal-filled elastomer fuser members have long been sought. At one time, it was predicted that:
"The metal of the metal-containing filler dispersed in the elastomer may be easily selected by one skilled in the art without undue experimentation by testing the metal-containing filler, such as a metal, metal alloy, metal oxide, metal salt or other metal compound, in an elastomer. The general classes of metals which are applicable to the present invention include those metals of Groups 1b, 2a, 2b, 3a, 3b, 4a, 4b, 5a, 5b, 6b, 7b, 8 and the rare earth elements of the Periodic Table." (U.S. Pat. No. 4,264,181 to Lentz et al, column 10, lines 42-53; also U.S. Pat. No. 4,272,179 to Seanor, column 10, lines 45-54.) PA1 R.sup.2 is alkyl having from 1 to 6 carbons; PA1 x/y is from about 99:1 to 70:30; and PA1 n is an integer such that said chains have a number average molecular weight of from 1.times.10.sup.3 to 1.times.10.sup.6 ; PA1 said chains being crosslinked by condensed polyfunctional silane moieties.
This prediction of easy selection of the metal for a metal-containing filler has proven false in the face of latter efforts in the art.
A metal-containing filler which provides good results in one elastomer may provide very poor results in another elastomer, even if the elastomers are very similar. In U.S. Pat. No. 4,264,181 to Lentz et al, good results were obtained when lead oxide was used as a filler in various fluoroelastomers (Viton E430, Viton E60C, Viton GH; Examples X, XI, XII). In U.S. Pat. No. 5,017,432 to Eddy et al, on the other hand, the use of lead oxide in similar fluoroelastomers (for example, Viton GF) is taught against on the basis that it would produce an unacceptable fuser member. In these fluoroelastomers, cupric oxide is preferred. Similarly, U.S. Patent No. 4,515,884 to Field et al, discloses a fuser member which utilizes metal oxide filled polydimethylsiloxane. The metal oxides are iron oxide and tabular alumina. Calcined alumina is described as being unsuitable per se. (Column 9, line 50-Column 10, line 47.)
An additional difficulty that has faced those attempting to produce metal-filled elastomer fuser members has recently been identified. In the past, it was thought that various materials' suitability for use in fuser roll base cushion layers in terms of their stability during use--i.e., their ability to resist degradation (as evidenced by weight loss), creep, and changes in hardness, during use in fuser rolls--could be determined by subjecting samples of the materials to conditions of continuous high temperature and continuous high stress (i.e., pressure), and then measuring the resultant changes in weight, shape (e.g., length), and hardness (e.g., storage modulus). However, J. J. Fitzgerald et al, "The Effect of Cyclic Stress on the Physical Properties of a poly(Dimethylsiloxane) Elastomer", Polymer Engineering and Science, Vol. 32, No. 18, (Sep. 1992), pp. 1350-1357; indicates that such testing does not accurately portray the stability the materials will exhibit during actual use in fuser roll base cushion layers and that dynamic testing, with cycles of loading and unloading is necessary. The publication cites other reports showing the same kind of results in studies of other elastomers. Accordingly, a device called a Mechanical Energy Resolver (sometimes alternatively referred to herein as an "MER") has been developed, which can be used to test samples of materials of interest for use in fuser roll base cushion layers. The device applies heat continuously to maintain the samples at a constant elevated temperature. The device also applies stress to the samples in the form of a compressive force, but does so in a manner such that the amount of compressive force applied varies cyclicly (i.e., sinusoidally). The results of such testing consistently correlate with, and therefore reliably predict, the degree of stability a material will exhibit in the base cushion layer of a fuser roll during actual use.
The realization of the need for dynamic testing has promised more accurate evaluation of filled elastomers, however, preparation of metal containing elastomers remains problematic. U.S. Pat. Nos. 4,515,884 to Field et al, and 5,017,432 to Eddy et al, cite large numbers of critical features or important aspects of their metal containing elastomers: choice of material (Field, column 9, lines 50-65 and column 10, lines 24-25), interaction of filler surface and elastomer (Field, column 9, lines 32-65), particle size (Field, column 10, lines 1-8 and lines 25-30; Eddy, column 9, line 65-column 10, line 3), concentration of metal-filler (Field, column 10, lines 9-23 and lines 31-47), capability of interacting with functional groups of release agent (Eddy, column 9, lines 26-30), reactivity of the metal filler with the elastomer (Eddy, column 9, lines 33-43), and acid-base characteristics of the metal filler (Eddy, column 9, lines 43-56). The lists of critical features and important aspects in Field and Eddy do not fully correlate. It is unknown whether this difference represents real differences in material characteristics or only differences in techniques and analysis.
One specific example of a condensation-crosslinked PDMS elastomer, which contains about 32-37 volume percent aluminum oxide filler and about 2-6 volume percent iron oxide filler, and which has been widely used and taught to be useful in fuser rolls, is sold under the trade name, EC4952, by the Emerson Cummings Co., U.S.A. However, it has been found that fuser rolls containing EC4952 cushion layers exhibit serious stability problems over time of use, i.e., significant degradation, creep, and changes in hardness, that greatly reduce their useful life. The present inventors have also found that MER test results correlate with and thus accurately predict the instability exhibited during actual use. Nevertheless, materials such as EC4952 initially provide very suitable resilience, hardness, and thermal conductivity for fuser roll cushion layers.
Some filled condensation-crosslinked PDMS elastomers are disclosed in U.S. Pat. No. 5,269,740 (copper oxide filler), U.S. Pat. No. 5,292,606 (zinc oxide filler), U.S. Pat. No. 5,292,562 (chromium oxide filler), U.S. Pat. No. 5,480,724 (tin oxide filler), U.S. Pat. No. 5,336,539 (nickel oxide filler). These materials all show much less change in hardness and creep than EC4952 or the PDMS elastomer with aluminum oxide filler. U.S. Pat. No. 5,292,606 and U.S. Pat. No. 5,480,724 disclose that tin oxide filler and zinc oxide filler can provide very good results in PDMS.
PDMS elastomers have a particular shortcoming in use. In order to improve release of toner from the fuser roller during fusing, polydimethylsiloxane fluid, referred to as fusing oil, is commonly applied to the fusing roller during use. This can improve release characteristics, but has been found to cause swelling of filled PDMS elastomer base cushions. Unfortunately, the amount of polydimethylsiloxane fluid absorbed by the base cushion inside and outside the paper path tends to differ, resulting in differential swelling and fusing problems. Alternative fusing oils can be used to reduce swelling; however, those fusing oils are much more expensive.
U.S. Pat. No. 4,970,098 to Ayala-Esquillin et al teaches a condensation cross-linked diphenylsiloxane-dimethylsiloxane elastomer having 40 to 55 weight percent zinc oxide, 5 to 10 weight percent graphite, and 1 to 5 weight percent ceric dioxide.
It would therefore be very desirable to be able to provide a fuser member with a base cushion layer comprising a condensation-crosslinked elastomer containing appropriate fillers, wherein the cushion layer material will exhibit, under conditions of elevated temperature and cyclic stress, good resistance to degradative weight loss, creep, changes in hardness, and swelling. The present invention meets this need. | {
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1. Field of the Invention
The present invention relates to a process for manufacturing elastomeric components of a tyre for vehicle wheels.
2. Description of the Related Art
Manufacturing of tyres for vehicle wheels involves formation of a carcass structure essentially made up of one or more carcass plies of a substantially toroidal shape and having their axially opposite side edges in engagement with respective annular reinforcing elements usually referred to as “bead cores”.
Provided on the carcass structure at a radially external position, is a belt structure comprising one or more belt strips in the form of a closed ring and essentially made up of textile or metallic cords suitably oriented with respect to each other and the cords belonging to adjacent carcass plies.
At a radially external position of the belt structure, a tread band is provided which usually consists of a band of elastomeric material of suitable thickness.
Finally, on the opposite sides of the tyre there is a pair of sidewalls, each of them covering a side portion of the tyre included between a so-called shoulder region disposed close to the corresponding side edge of the tread band, and a so-called bead located at the respective bead core.
To the aims of the present invention it should be pointed out that by the term “elastomeric material” it is intended a composition comprising at least one elastomeric polymer and at least one reinforcing filler. Preferably this composition further comprises additives such as a cross-linking and/or plasticizing agent, for example. Due to the presence of the cross-linking agent, this material can be cross-linked through heating so as to form the final article of manufacture.
Traditional production methods essentially provide for the above listed tyre components to be first made separated from each other, to be then assembled during a tyre building step.
However, there is a general tendency in the present technologies to resort to production methodologies enabling production and storage of semi-finished products to be minimised or possibly eliminated.
For the purpose, manufacturing processes have been proposed that aim at obtaining given tyre components such as tread band, sidewalls or others, by laying onto a toroidal support carrying the tyre being worked, a continuous elongated element of elastomeric material of a reduced section as compared with that of the component to be obtained, which elongated element is such arranged as to form, around the rotation axis of the tyre, a plurality of consecutive coils disposed in side by side and/or overlapped relationship so as to define the component itself in its final configuration.
WO 01/36185 A1 in the name of the same Applicant, discloses a method of manufacturing components of elastomeric material in a tyre for vehicle wheels comprising the steps of: feeding a continuous elongated element from a delivery member disposed close to a toroidal support for application of said elongated element onto the toroidal support itself; giving the toroidal support a rotatory motion around its geometrical rotation axis, so that the elongated element is circumferentially distributed on the toroidal support; carrying out controlled relative displacements for transverse distribution between the toroidal support and the delivery member to form a tyre component with said elongated element which is defined by a plurality of coils laid down in side by side or mutual overlapped relationship according to a preestablished deposition pattern depending on a predetermined cross-section outline to be given to said component. In particular said document teaches that if the peripheral speed of the toroidal support at the point of application of an elongated element is such controlled that a conveniently higher value than the feeding speed of the elongated element itself by the delivery member is maintained, adhesion of the applied elongated element is greatly improved and important advantages in terms of operating flexibility are achieved. In particular, the possibility of conveniently modifying the cross-section sizes of the elongated element is obtained so as to adapt the latter to the thickness of the component to be made, at the different points of the cross-section outline of the component itself.
Document EP 1 279 486 A2 discloses a method of manufacturing a shaped rubber element through extrusion of a strip by an extrusion process comprising a screw extruder, a gear pump and an extruder head having an extrusion nozzle, said units being connected in series with each other. Said method comprises the steps of: feeding a rubber strip onto a rotating support, along a passage extending from said screw extruder to said extrusion nozzle of the extruder head, wherein said passage is substantially a straight passage; and directly or indirectly applying the rubber strip to an outer peripheral surface of the support.
Document EP 1 201 414 A2 discloses a method of manufacturing a tyre comprising: assembling the non-vulcanized rubber components to form a green tyre, vulcanizing the green tyre and wrapping a non-vulcanized rubber strip in such a manner that windings on the whole have a shape of a predetermined cross-section for at least one non-vulcanized rubber component so as to form at least one of the non-vulcanized rubber components.
Document EP 1 211 057 A2 discloses a method of manufacturing a tyre in which, during formation of a green tyre, at least one constituent element, the sidewalls for example, is formed through expansion in a radially external direction of a central portion of a substantially cylindrical carcass band, a non-vulcanized rubber strip being then wound up, junction of the rubber strip taking place on an outer peripheral surface of the expanded carcass band. | {
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The present invention relates to products for men suffering from incontinence and more particularly to an absorbent penis shield that is securable over the head of a user""s penis to absorb urine that may be emitted during an incontinence episode; the absorbent penis shield including an absorbent member and a moisture proof section; the absorbent member including an absorbent penis head receiving cup positioned in the center thereof between opposed two top and bottom absorbent sections and between opposed left and right absorbent sections; the moisture proof section having the entire absorbent member bonded to a penis facing side thereof and having left and right fastener portions on the penis facing side on either side of the bottom absorbent section and a center fastener section on an exterior facing side adjacent to the top absorbent section; the left and right fastener portions each being wrappable around a respective side of a penis to be secured within the absorbent penis shield and into connection with the center fastener section in a manner to form a constriction around a base section of a penis to hold a head portion of a user""s penis within the absorbent penis head receiving cup.
Incontinent men often feel uncomfortable wearing a diaper or other incontinence appliance that surrounds the lower portion of the wearer""s torso. It would be desirable for these individuals to have an incontinence product for absorbing urine emitted during an incontinence episode that could be secured over the head of the user""s penis to absorb urine and which would take the place of a large diaper sized appliance.
It is thus an object of the invention to provide an absorbent penis shield that includes an absorbent member and a moisture proof section; the absorbent member including an absorbent penis head receiving cup positioned in the center thereof between opposed two top and bottom absorbent sections and between opposed left and right absorbent sections; the moisture proof section having the entire absorbent member bonded to a penis facing side thereof and having left and right fastener portions on the penis facing side on either side of the bottom absorbent section and a center fastener section on an exterior facing side adjacent to the top absorbent section; the left and right fastener portions each being wrappable around a respective side of a penis to be secured within the absorbent penis shield and into connection with the center fastener section in a manner to form a constriction around a base section of a penis to hold a head portion of a user""s penis within the absorbent penis head receiving cup.
Accordingly, an absorbent penis shield is provided. The absorbent penis shield includes an absorbent member and a moisture proof section; the absorbent member including an absorbent penis head receiving cup positioned in the center thereof between opposed two top and bottom absorbent sections and between opposed left and right absorbent sections; the moisture proof section having the entire absorbent member bonded to a penis facing side thereof and having left and right fastener portions on the penis facing side on either side of the bottom absorbent section and a center fastener section on an exterior facing side adjacent to the top absorbent section; the left and right fastener portions each being wrappable around a respective side of a penis to be secured within the absorbent penis shield and into connection with the center fastener section in a manner to form a constriction around a base section of a penis to hold a head portion of a user""s penis within the absorbent penis head receiving cup. | {
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1. Field of the Invention
The present invention relates to a wireless communication terminal used in a wireless communication system that supports broadcast/multicast services.
Priority is claimed on Japanese Patent Application No. 2005-159600, filed May 31, 2005, the content of which is incorporated herein by reference.
2. Description of the Related Art
In wireless communication in which wireless communication terminals move freely within an area in which the wireless communication is provided, a technique called “handoff” is used to maintain the communication when a wireless communication terminal goes out of an area covered by one wireless base station and moves to an area of an adjacent different wireless base station or another sector. One method for achieving such a handoff is a method in which a signal for measurement is sent by respective wireless base stations with certain radio field intensity for measurement of the radio field intensity and a wireless communication terminal receives the signals and switches to another wireless base station. This method is an important technique for maintaining a communication channel since the status of reception of the wireless channel is maintained in a certain condition. For example, details of handoffs in accordance with the IS95 scheme are described in many documents, such as Japanese Unexamined Patent Application, First Publication No. 2003-189346.
On the other hand, from the viewpoint of effective utilization of wireless channels, a new service for wireless communication called Broadcast Multicast Service (BCMCS) has been proposed. This service is one type of broadcast service in which a plurality of wireless communication apparatuses simultaneously share a single communication channel called a “broadcast channel” for receiving information by the plurality of wireless communication apparatuses from the one channel providing a service of a broadcast type (i.e., a broadcast service). The service enables each wireless base station to broadcast common information to wireless communication terminals within their respective areas. Furthermore, since a respective channel is not required to be established by each wireless communication terminal, it becomes possible to distribute a large volume of data, such as news or movies, thereby improving utilization of the wireless channel. Furthermore, since it is possible to control each base station, unlike in a general wide-area broadcast service, distribution of information that is more closely related to the local area is made possible.
The procedure for information distribution of BCMCS will be described briefly. A wireless base station sends notification information relating to services that the wireless base station can offer to all wireless communication terminals within its wireless area. A wireless communication terminal receives the information and starts to receive a service it desires to receive by registering identification information that specifies the service with the wireless base station. The wireless base station receives the registering information from the wireless communication terminal and starts to provide the service if the service desired by the wireless communication terminal is not being provided at present (the information content is not being provided). The BCMCS stops provision of information content when no user is using the service from the viewpoint of effective utilization of wireless resources, and frees the communication channel used for the BCMCS so that the channel can be used as a general channel.
However, this method has the shortcoming that when a wireless communication apparatus using the BCMCS moves within the communication area of the wireless base station and hands off to another wireless area (for example, a cell or a sector). With the conventional wireless communication technologies, it is possible to maintain the wireless communication channel. However, the wireless base station to which a wireless communication terminal is currently connected and is providing the service does not notify whether or not the broadcast service is currently being provided. The statuses of services provided by a handoff destination base station, such what types of service is being provided, are unknown. As a result, the service provided through the BCMCS cannot be maintained. | {
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Golf has become increasingly popular as the standard of living has greatly improved over the years. More and more people play golf as hobby or even as competitive sport. In order to improve player performance, rigorous analysis of swing and hit data obtained from practice sessions is utilized to adjust the player's postures and strength, as well as the weight of the golf club.
Referring to FIG. 1, an intelligent golf club head 1 of a conventional golf club includes a main body 10 formed with an installation hole 100, and an intelligent counterweight unit 11 received in the installation hole 100. The intelligent counterweight unit 11 includes a coupling unit 111 positioned in the installation hole 100, an intelligent unit 112 disposed inside the coupling unit 111, and a cover 113 connecting to the intelligent unit 112 and closing the installation hole 100. The intelligent counterweight unit 11 can serve as a counterweight by its own weight, and the intelligent unit 112 can monitor and output numerous data generated during the swing and hit actions of the head unit 1, thus enabling the players to adjust their swing and hit actions based on the data output after being analyzed.
Further referring to FIG. 2, since the intelligent counterweight unit 11 is received in the main body 10, the impact on the main body 10 when the golf club head 1 hits a golf ball will be transmitted to the intelligent counterweight unit 11. The impact has a great influence on the intelligent unit 112, particularly in the case where the cover 113 is in direct contact with the intelligent unit 112, wherein the larger the contact area between the cover 113 and the intelligent unit 112 is, the greater the impact on the intelligent unit 112 is. Therefore, if the excessive impact generated during the golf club head 1 hitting the golf ball cannot be effectively dispersed, the intelligent unit 112 will be relatively susceptible to damage, thereby affecting the service life of the intelligent counterweight unit 11. | {
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This invention pertains to a carton for carrying a plurality of similar articles and, more particularly, relates to a carton for packaging a plurality of bottles containing a light sensitive product. Cartons for carrying bottles and the like are well-known in the prior art, such as, for example, as shown in patent U.S. Pat. No. 3,670,950. Also, a number of cartons have been developed for carrying light sensitive liquids, such as beer. Examples of such cartons are shown in patents U.S. Pat. No. 3,688,972; and U.S. Pat. No. 3,692,232. Such prior art cartons suffer from several serious deficiencies to which the present invention is addressed.
One deficiency of the prior art cartons is that they almost invariably contain openings, or finger grip accesses, through one of the major walls of the carton which enable light to enter to some extent. When light sensitive materials are packaged in the bottles contained by the carton, such light entry can seriously damage, or shorten the shelf life of, the packaged materials. Another serious disdvantage of the prior art cartons is that, almost invariably, the finger grip access openings are provided in the top wall of the carton, subjecting the sides of the openings to direct sheer forces when the carton is carried. These sheer forces dictate the use of a heavy weight board to ensure that the carton does not tear away from the customer's hand. In an effort to solve this problem some prior art cartons have included a double thickness of paperboard in the vicinity of the finger grips. However, each layer has been permitted to function independently of the other layer giving rise to the possibility that one layer alone could be subjected to the entire weight of the carbon and its contents. These deficiencies of the prior art have resulted in cartons of a significantly heavier weight paperboard than made possible by the present invention.
Another disadvantage of prior art cartons, which are to some extent meant to be closed to light, is that opening them usually involves either tearing away large sections of the carton or completely mutilating the carton so that it essentially ceases to function as a closable container once opened. As will be seen, one feature of the present invention includes provisions for easily opening the carton and reclosing same after part of the contents are removed. | {
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In the field of semiconductor device design, it is known that mechanical stresses within the device substrate can affect device performance. Stress engineering has come to play an important role in improving the performance of semiconductor devices. In the case of field-effect transistors (FETs), stress is applied to the channel region of the FET to cause increased mobility of electrons or holes, which in turn gives a substantial improvement in device speed. In a typical CMOS integrated circuit device, both n-type and p-type FETs (NFETs and PFETs respectively) are used. The stress components for the NFET and PFET in a given device must be engineered and applied differently, in accordance with the type of device and whether the direction is longitudinal (on the same axis as the channel current) or transverse to the channel current. It is known that the best stress design provides tensile stress in both longitudinal and transverse directions in the channel region under the gate of the NFET, but longitudinal compressive stress and transverse tensile stress in the channel region under the gate of the PFET.
FIGS. 1A and 1B schematically illustrate a typical device with the desired stress arrangement. FIG. 1A is a cross-section view of NFET and PFET gate structures 10, 20 formed on substrate 1 with an isolation region 15 (generally shallow-trench isolation or STI) between them. The NFET and PFET gate materials 11, 21 have channel regions 13, 23 beneath them. FIG. 1B is a plan view of the channel regions with the desired stresses, where arrows T and C represent tensile stress and compressive stress respectively.
U.S. Pat. No. 6,825,529 to Chidambarrao et al., assigned to one of the assignees of the present invention, describes the use of nitride spacers (12 and 22 in FIG. 1A) with different values of intrinsic stress to obtain the desired longitudinal stresses in the channel regions. According to Chidambarrao et al., it is also known that a nitride layer with high intrinsic stress, deposited over the completed NFET or PFET device, will induce corresponding stress in the channel.
The nitride films used in these techniques are deposited by plasma-enhanced CVD (PECVD). Whether a film has intrinsic tensile stress or compressive stress depends on the details of the deposition process. A number of PECVD processes and tools have been used in attempts to maximize intrinsic compressive stress in nitride films used in the PFET devices. At present the greatest compressive stress achievable in PECVD nitride appears to be about −2.6 GPa. There is a need for a process which can provide significantly greater intrinsic compressive stress in the deposited nitride film. | {
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Since thermotropic liquid-crystalline polymer uses expensive aromatic monomers as raw material to result in high price of the polymer, cut-down of manufacturing cost thereof becomes an important problem. As one of cut-down manners of manufacturing cost, attainment of high yield of the polymer is considered.
As for technique of attaining high yield of the polymer, there is such manner that, after termination of polymerization reaction, temperature of a reaction pot is raised at discharging the polymer to lower molten viscosity of the polymer. However, the polymer is thermally degraded to lead to discoloration and generation of blackish brown polymer and, when thermal degradation is heavy, gas of low boiling components derived from raw material (such as phenol (PhOH), benzoic acid (BA), 4-hydroxybenzoic acid (HBA) or phenol ester compound thereof (HBA-Ph)) or black speck (substance like carbide, abbreviated to BS) generates to give an adverse effect on product quality. Further, there is such problem that, when gas of low boiling components fills in a reaction pot, discharge becomes unstable to lower collection rate from the reaction pot.
Among low boiling point components, in particular components relating to phenol (PhOH, HBA-Ph) are caused by phenol generating by thermal degradation of 4 -hydroxybenzoic acid (HBA) residue that is generally used for thermotropic liquid-crystalline polymer. Especially, when acylation-deacylation is conducted in one pot to perform manufacture, degradation (decarboxylation reaction) from HBA to phenol occurs in no small way from the early stage of polymerization. Accordingly, in a liquid-crystalline polymer in which HBA is the main component, a technique is expected for inhibiting decarboxylation reaction of HBA component during polymerization.
In order to inhibit decarboxylation reaction, a method is proposed (see JP-A-2-153922), in which aromatic diol is acylated followed by reaction with HBA to give oligomer, which is subjected to polycondensation with aromatic dicarboxylic acid. However, it can not be applied to a skeleton in which hydroxycarboxylic acid occupies most part. Further, it cannot be said that inhibition of conversion of HBA into phenol is sufficient. Use of an excess acylating agent to a hydroxyl group or an amino group tends to inhibit decarboxylation reaction. However, by this manner, discoloration of polymer or thickening due to side reaction becomes significant. The present applicant proposed previously a method in which generation of low boiling point gas is inhibited by maintaining a charge amount of a raw monomer, an amount of an acylating agent and an amount of a catalyst in a specified relationship to obtain a high quality polymer without discoloration due to thermal degradation and the like at high yield (see JP-A-2002-363281). However, since the metal salt catalyst used for accelerating acylation, basically, also has an effect of accelerating decarboxylation reaction, the inhibition effect had a limit. | {
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1. Field of the Invention
The field of this invention relates to glass filled polyamide-imide phthalamide copolymers containing about 1 to about 10 percent phthalic anhydride prepared in an organic solvent, and to molding powders and molded articles prepared therefrom. More particularly, the field of this invention relates to glass filled polyamide-imide isophthalamides comprising about 1 to about 10 percent phthalic anhydride.
2. Background
Amide-imide polymers are a relatively new class of organic compounds known for their solubility in nitrogen-containing organic solvents when in the largely polyamide form. The major application of the amide-imide polymers has been as wire enamels. This is illustrated in U.S. Pat. Nos. 3,661,832 (1972); 3,494,890 (1970); and 3,347,828 (1967).
Compositions prepared from isophthalic acid and diamines and aliphatic diamines have found application in coatings and films. The prior art on this is summarized in U.S. Pat. No. 3,444,183 (1969).
Reinforced polyhexamethylene isophthalamides have been used to produce articles as disclosed in U.S. Pat. No. 4,118,364 (1978). However, the physical properties of these reinforced polyhexamethylene isophthalimides are insufficient for use in engineering plastics since their tensile strength and the continuous service temperature do not meet those required for engineering plastics.
U.S. Pat. No. 4,313,868, discloses copolymers and molding compositions prepared from acylhalide derivatives of dicarboxylic acids, acylhalides of tricarboxylic aromatic anhydrides and aromatic diamines. That reference also discloses glass-filled copolymers. These products, useful as engineering plastics, have a tendency to have flow problems. These problems are overcome when about 1 to about 10 percent phthalic anhydride is added to the polymer.
U.S. Pat. No. 4,136,085 discloses that the addition of phthalic anhydride to compositions based on the acylhalide derivative of trimellitic anhydride and diamines did not improve the flow properties of the polymer. Applicant has discovered that when phthalic anhydride is added to his polymer, the flow is greatly improved.
The general object of this invention is to provide amide-imide and polyamide copolymers comprising about 1 to about 10 percent phthalic anhydride moieties. A more specific object of this invention is to provide amide-imide and polyamide copolymers comprising about 1 to about 10 percent phthalic anhydride reinforced with glass fibers, glass beads and mixtures thereof. A more specific object of this invention is to provide a process for incorporating 1 to about 10 percent phthalic anhydride into polyamide-imide polyamide copolymers. Another object is to provide amide-imide and amide polymers prepared from aromatic diamines and mixtures of an acylhalide derivative of an aromatic tricarboxylic anhydride and an acylhalide derivative of an aromatic dicarboxylic acid and about 1 to about 10 percent phthalic anhydride wherein said polymer contains from about 30 to about 60 weight percent glass fibers, glass beads, or mixtures of these. Other objects appear hereinafter.
I have now found that improved amide-imide amide copolymers can be obtained by reacting acylhalide derivatives of benzene tricarboxylic anhydride and acylhalide derivatives of aromatic dicarboxylic acids with aromatic diamines and about 1 to about 20 percent phthalic anhydride. I have also discovered that these polymers comprising about 1 to about 10 percent phthalic anhydride can be filled with from about 30 to about 60 weight percent with glass fibers, glass beads, or a mixture thereof. Suitably, the aforementioned molding compositions may contain from about 30 to about 50 weight percent of glass fibers, glass beads, or a mixture thereof. Our studies have shown that if the teachings of U.S. Pat. No. 4,313,868 are followed specifically in Example 2, great care must be taken in processing this trimellitic anhydride capped resin, as heat treatment of the polymer at about 450.degree. to about 470.degree. F. for periods greater than two hours will yield material having a zero melt flow at 650.degree. F., 1/8 inch die and 5,000 psi. Pellitization and injection molding of the polymer will yield greater cavity pressure and injection molding cycle times are less than 40 seconds. Injection molding of the polyamide-imide amide polymer with about 1 to about 10 percent by weight phthalic anhydride in place of the 2 percent trimellitic acid used in Example 2 of U.S. Pat. No. 4,313,868 shows a substantial improvement in the melt flow values and stability of the polymer. Compositions comprising up to 60 percent by weight glass fiber show an improvement in cavity pressure and injection molding cycle when the polymer comprises about 1 to about 10 percent phthalic anhydride compared to polymers not having any phthalic anhydride moieties.
Our studies have shown that fully aromatic amide-imide polymers are very expensive and need special injection molding equipment capable of withstanding injection molding temperatures in the range of 600.degree. to 700.degree. F. at the molding pressure in excess of 20,000 pounds per square inch. Our novel amide-imide amide copolymer comprising about 1 to about 10 percent phthalic anhydride and glass filled copolymers are much more economical than conventional polyamide-imide copolymers disclosed in U.S. Pat. Nos. 4,016,140 (1977) and 3,573,260 (1971) and yet retain the same thermal and mechanical properties of the copolymers disclosed in the aforementioned patents. This is a significant advance in the art and is wholly unexpected.
The use of polyamide-imide polymers are engineering plastics has been limited only by their relatively high cost. Thus, when the inherent cost can be brought down, the commercial application of these polymers will be greatly expanded. The copolymers of this invention have large cost advantages over the prior art compositions and thus promise to expand the commercial applications of these polymers.
The copolymers of this invention are prepared by reacting a mixture of an acyl halide derivative of an aromatic tricarboxylic acid anhydride and acyl halide derivatives of aromatic dicarboxylic acids with aromatic diamines.
The novel injection moldable copolymers of this invention comprise recurring polyamide A units of ##STR1## which are capable of undergoing imidization and polyamide B units of ##STR2## wherein the molar ratio of A units to B units is about 80 to 20 to 20 to 80, preferably 1 to 1 and wherein R is a divalent aromatic hydrocarbon radical of from about 6 to about 20 carbon atoms or two divalent hydrocarbons joined directly or by stable linkages selected from the group consisting of --O--, methylene, --CO--, --SO.sub.2 --, and wherein X is a divalent aromatic radical and .fwdarw.denotes isomerization and wherein the copolymer comprises about 1 to about 10 percent by weight of phthalic anhydride moieties.
In the injection molded form, the polyamide A units have converted to the polyamide-imide A' units and the copolymer is comprised of recurring polyamide-imide A' units of ##STR3## and polyamide B units of ##STR4## wherein the molar ratio of A' to B units is about 80 to 20 to 20 to 80, preferably 1 to 1, and wherein R and X are defined as above and wherein the copolymer comprises about 1 to about 10 percent by weight of phthalic anhydride moieties.
The copolymers of this invention are prepared from acyl halide derivatives of dicarboxylic acid such as isophthalic acid or terephthalic acid and an anhydride-containing substance and aromatic diamines. Useful acyl halide derivatives of dicarboxylic acid include ##STR5## and related compounds. Suitably, the anhydride-containing substance is an acyl halide derivative of the acid anhydride having a single benzene or lower acyl-substituted benzene ring. The preferred anhydride is four acid chloride of trimellitic anhydride (4 TMAC).
Useful aromatic diamines include para- and meta-phenylenediamine, oxybis (aniline), thiobis (aniline), sulfonylbis (aniline), diaminobenzophenone, methylenebis (aniline), benzidine, 1,5-diaminonaphthalene, oxybis (2-methylaniline), thiobis (2-methylaniline), and the like. Examples of other useful aromatic primary diamines are set out in U.S. Pat. No. 3,494,890 (1970) and U.S. Pat. No. 4,016,140 (1977) both incorporated herein by reference. The preferred diamine is meta-phenylene-diamine.
I have found that the polyamide-imide amide copolymers are improved by the addition of reinforcing material; particularly the mechanical properties of the copolymers are improved if these copolymers contain from 30 to 60 percent by weight glass fibers, glass beads or a mixture thereof. In the preferred range the copolymers contain 30 to 40 percent by weight of the glass reinforcing material, glass fibers, glass beads, or a mixture thereof. Suitable reinforcing materials can be glass fibers, glass beads, glass spheres, glass fabric. The glass fibers are made of alkali-free boron-silicate glass (E-glass) or alkali-containing C-glass. The thickness of the fibers is preferably on average between 3 .mu.m and 30 .mu.m. It is possible to use both long fibers with an average length of from 5 to 50 mm and also short fibers with an average filament length of from 0.05 to 5 mm. In principle, any standard commercial-grade fibers, especially glass fibers, may be used. Glass beads ranging from 5 .mu.m to 50 .mu.m in diameter may also be used as reinforcing material.
The reinforced polyamide-imide amide copolymers may be prepared in various ways. For example, so-called rovings, endless glass fiber strands, are coated with the polyamide melt and subsequently granulated. The cut fibers or the glass beads may also be mixed with granulated polyamide and the resulting mixture melted in a conventional extruder, or alternatively the fibers may be directly introduced into the polyamide melt through a suitable inlet in the extruder.
Injection molding of the novel glass-filled polymer is accomplished by injecting the copolymer into a mold maintained at a temperature of about 300.degree. to 450.degree. F. In this process a 25 to 28 second cycle is used with a barrel temperature of about 600.degree. to 650.degree. F. The injection molding conditions are given in Table I.
TABLE I ______________________________________ Mold Temperature 350.degree. F. to 450.degree. F. Injection Pressure 15,000 to 19,000 psi and held for 1 to 3 seconds Back Pressure 100 to 220 psi Cycle Time 25 to 28 seconds Extruder: Nozzle Temperature 600.degree. F. to 630.degree. F. Barrels: Front heated to 600.degree. F. to 630.degree. F. Screw: 20 to 25 revolutions/minute ______________________________________
The mechanical properties of the polymers prepared in the Examples are given in Tables 2, 3, and 4 and show that these polymers have excellent mechanical and thermal properties.
Cavity pressure measurements are used as quality control checks of polyamide-imide resin viscosity. Pressure buildup during the filling of an injection molded part is measured at a point in the cavity (ejector pin). This is accomplished by placing a pressure transducer behind the ejector pin and recording the pressure with a chart recorder or other readout device. Cavity pressure normally rises as the mold is being filled and peaks as the molten resin is packed into the cavity. As the resin solidifies, cavity pressure decreases.
We have found that resins that have low cavity pressure process poorly and that spiral flow measurements were not sensitive enough to discriminate between resins in the viscosity range of interest. Low cavity pressures indicate a large pressure drop between injection and cavity pressures. This indicates higher resin viscosities. In the same manner, high cavity pressures indicate less pressure change between injection and cavity pressures, suggesting lower resin viscosities.
Amide-imide polymer and copolymer viscosities had been measured by spiral flow determinations previous to the implementation of the cavity pressure procedure, see U.S. Pat. No. 4,224,214. Cavity pressure was selected over spiral because of its greater sensitivity. The cavity pressure test has been implemented as an amide-imide homopolymer and copolymer quality control procedure. Like spiral flow, cavity pressure is a test that can be done conveniently in a molder's shop.
Resins were dried in a vacuum (2 mm Hg) oven at 300.degree. F. for at least 16 hours before testing. Moisture in amide-imide homopolymer copolymers has a very significant effect on its flow properties, therefore special care was taken to be sure the samples were properly dried. This drying procedure was used before making flow rate and cavity pressure measurements.
The flow rate procedure was patterned after the standard method described in ASTM D1238. I used a 335.degree. C. (635.degree. F.) barrel temperature with a 30 minute preheat time. This is about the largest set of weights that can be used safely with the standard extrusion plastometer apparatus. I used a standard 0.0825 in. diameter, and a 0.315 in. long orifice.
Special care was taken to be sure that each flow rate measurement was started when an equivalent volume of resin was in the barrel. Previous rheology work indicated that there is a very large "barrel height" effect on amide-imide homopolymers and copolymers. Each flow rate measurement was initiated while the top of the piston collar was between the two scribe marks on the piston. This precaution is also required by ASTM in method D1238.
In a preferred embodiment, 1 mole meta-phenylene-diamine is dissolved in a nitrogen-containing solvent such as dimethylacetamide or N-methylpyrolidone and about 1 to about 10 percent by weight phthalic anhydride is added. A mixture of the 4-acid chloride of trimellitic anhydride and the acid chloride form of isophthalic acid in a molar ratio of 1 to 1 is added to the diamine solution over two hours at about 25.degree.-35.degree. C. The isophthalic anhydride and the 4-acid chloride of trimellitic anhydride may be either dry blended or molten. The viscous solution is then heated at about 50.degree. C. for one hour and the polymer is recovered by precipitation into water. The product is washed thoroughly and dried to a solids content in excess of 96%. The polymer is then dry blended with glass fiber, pelletized and injection molded under molding conditions as set forth in Table I. The mechanical properties of the copolymer are given in Tables 2, 3, and 4. | {
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The present invention relates to a data processor having a memory controller capable of controlling an external memory synchronously with a clock, specifically to a technique effective in use for a microcontroller provided with an interface controller for a DDR-SDRAM (double data rate SDRAM) memory.
The synchronous memory that behaves synchronously with a clock, represented by an SDRAM (Synchronous Dynamic Random Access Memory), is widely used for a frame buffer for graphics and a main memory in a CPU (Central Processing Unit) and so forth. For example, the SDRAM has plural memory banks, and each memory bank has an address decoder, memory array, sense amplifier array, and so forth, and each is made independently controllable. The plural memory banks are configured to behave in pipeline, which makes a high-speed access possible. Especially, the synchronous memory with a DDR configuration performs data input/output with the outside synchronously with both the rise edge and fall edge of a clock, which further increases the access speed compared to the synchronous memory with an SDR (single data rate) configuration. The patent document 1 discloses a multi-bank SDRAM. The patent document 2 discloses a system controller incorporating graphic ports and an SDRAM controller. The synchronous memory is connected to such a system controller that performs the access control thereto.
[Paten Document 1]
Japanese Unexamined Patent Publication No. Hei 10(1998)-189889
[Paten Document 2]
Japanese Unexamined Patent Publication No. 2000-132503 (FIG. 6) | {
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1. Field of the Invention
The present invention relates to a gun barrel cleaning tool and more particularly pertains to allowing a user to clean and lubricate an area between a vent rib and a barrel on a gun with a gun barrel cleaning tool.
2. Description of the Prior Art
The use of gun cleaning tools is known in the prior art. More specifically, gun cleaning tools heretofore devised and utilized for the purpose of cleaning guns are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
By way of example, U.S. Pat. No. 4,291,477 to Carlton discloses a gun barrel cleaning device. U.S. Pat. No. 4,716,673 to Williams et al. discloses a gun barrel cleaner and container therefore. U.S. Pat. No. 4,930,240 to Bice discloses a gun barrel cleaning device. U.S. Pat. No. 5,075,998 to Selleck discloses a gun cleaning rod with swivel handle. U.S. Pat. No. 5,171,925 to Mekler discloses a gun barrel cleaning tool.
While these devices fulfill their respective, particular objective and requirements, the aforementioned patents do not describe a gun barrel cleaning tool that allows a user to readily clean an area between a vent rib and barrel on a rifle, handgun, or other like ballistic weapon.
In this respect, the gun barrel cleaning tool according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of allowing a user to clean and lubricate an area between a vent rib and a barrel on a gun.
Therefore, it can be appreciated that there exists a continuing need for new and improved gun barrel cleaning tool which can be used for allowing a user to clean and lubricate an area between a vent rib and a barrel on a gun. In this regard, the present invention substantially fulfills this need. | {
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Data compression techniques are used to encode data using fewer bits than the original data set. Lossless compression enables the encoded data to be completely reconstructed from the compressed data. This complete reconstruction is distinguished from the approximate reconstruction that occurs with lossy compression.
The same numbers are used throughout the disclosure and the figures to reference like components and features. Numbers in the 100 series refer to features originally found in FIG. 1; numbers in the 200 series refer to features originally found in FIG. 2; and so on. | {
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The invention relates to devices and methods for warming chilled blood delivered from a disposable storage bag in a pressure infusion device to near normal body temperature before infusion into a patient; the invention relates more particularly to improvements in such blood warming devices to prevent overheating of blood in the blood warming jacket in the event that movement of blood in the blood warming jacket is slowed or stopped.
It is well known that when massive transfusions of blood are required, the blood, which is normally chilled in disposable plastic storage bags at temperatures of about 4.degree. Centigrade must first be warmed to near normal body temperature in order to avoid hypothermia and other complications. A variety of prior blood warming devices have been proposed for receiving chilled blood from pressure infusion devices, heating the blood as it is forced through a tube from the pressure infusion device, before the heated blood is infused by means of a catheter or needle into a patient. Some of the prior blood warming devices consist of simply passing a coiled tube through which the chilled blood passes through a heated water bath before the blood is forced into the infusion catheter. Other prior devices include a blood warming jacket that is inserted into a blood warming device. The blood is forced into an inlet of the blood warming jacket and through a thin channel in the disposable blood warming jacket. An outlet of the blood warming jacket is connected to a tube to conduct the warmed blood into the infusion catheter.
It is generally accepted that blood should not be heated above 42.degree. Centigrade before being infused into a patient's body. All prior known prior blood warming devices utilize water or electrical heating elements to effectuate thermal transfer of heat to the blood.
However, both water and the metal of electrical heating elements have high thermal mass, i.e., high thermal heat capacity. Such high thermal mass may cause "temperature overshoot" of the blood being warmed when the movement of such blood through the heating jacket or coiled tube is halted (for example by temporary loss of pressure in the pressure infusion device) because a large amount of heat contained in the water or electrical heating element continues to be transferred into the stationary blood.
The prior blood warming devices have been unable to achieve the high infusion rates that are necessary in certain instances when massive transfusions are required, heat the chilled blood to the necessary minimum temperature during such massive transfusions, and still avoid the risk of overheating a portion of the blood in the event of a temporary slowing or halting of the flow of blood through the blood warming device.
It is known that in certain emergency circumstances, massive blood transfusion rates of up to 1000 milliliters per minute may be required. It would be desirable that a blood warming device be able to precisely heat chilled blood to 40.degree. C. for infusion rates as low as 200 milliliters per minute to infusion rates as high as about 1000 milliliters per minute, without any danger of any blood cells being heated above 42.degree. Centigrade, even in the event of a malfunction that halts flow of blood in the blood warming device.
A decrease in a patient's body temperature to a level below about 35.degree. Centigrade may seriously jeopardize the patient's chance of survival. One risk is that of increasing the likelihood of ventricular fibrillation.
Another risk is that of imparing the ability of the patient's body to withstand blood loss. The various risks of hypothermia are described in detail in "A Review of Blood Warmers for Massive Transfusion", W. J. Russell, "Anesthesia and Intensive Care", Volume II, No. 2, May 1974, page 109, and in "Blood Warmers", Health Devices, Volume 13, No. 9, July 1984, both of which are incorporated herein by reference. U.S. Pat. No. 3,614,385 discloses a blood warming device using a liquid heating medium. U.S. Pat. Nos. 2,063,902, 3,315,681, 3,475,590, and 3,590,215 disclose blood warming devices that use dry heating plates or elements to conduct heat directly to the blood. Various prior patents, such as U.S. Pat. No. 4,426,923, disclose use of heated air to warm substances such as food.
The above July, 1984 "Health Devices" article states, "As the technology stands now, there is much room for improved warming capacity." As indicated above, there are occassions when massive transfusion rates much greater than 160 milliliters per minute rate (presently accepted as a maximum "massive" infusion rate) are required in order to save the life of a patient.
No known prior blood warming device is capable of safely raising the temperature of chilled blood up to at least 40.degree. Centigrade at flow rates as high as one liter per minute, which in some cases would be desirable. As several of the above articles indicate, there is a considerable risk in infusing blood into a patient if any of the blood cells have been heated to above approximately 42.degree. Centigrade. Hemolysis of the red blood vessels may occur, leading to poor oxygen transport in the blood, kidney failure, and increased potassium levels that can cause cardiac irregularity.
Thus, despite the advances in blood warming devices over the last decade to prevent hypothermia and other complications during massive transfusions, there is still a clearly unmet need for a greatly improved, inexpensive, easily maintained, easily operated, safe blood warming device capable of heating massive transfusions of chilled blood without appreciable risk of overheating any of the transfused blood. | {
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Successful gene therapy depends on the efficient delivery to and expression of genetic information within the cells of a living organism. Most delivery mechanisms used so far involve viral vectors. Viruses have developed diverse and highly sophisticated mechanisms to achieve this goal including crossing of the cellular membrane, escape from lysosomal degradation, delivery of their genome to the nucleus and, consequently, have been used in many gene delivery applications.
Non-viral vectors, which are based on receptor-mediated mechanisms (Perales et al., Eur. J. Biochem. 226:255-266, 1994; Wagner et al., Advanced Drug Delivery Reviews 14:113-135, 1994) or on lipid-mediated transfection (Eelgner et al., Proc. Natl. Acad. Sci. U.S.A. 84:7413-7417 1987; Behr et al., Proc. Natl. Acad. Sci. U.S.A. 86:6982-6986, 1989; Gao et al., Biochem. Biophys. Res. Communic. 179:280-285, 1991; Behr, Bioconjugate Chemistry 5:382-389, 1994; Fahrhood et al., Annals New York Academy of Sciences, 716:23-35, 1994; Ledley, Human Gene Therapy 6:1129-1144, 1995) promise to have advantages with respect to large--scale production, reduced risks related to viral vectors, targeting of transfectable cells, lower immunogenicity and the capacity to deliver larger fragments of DNA.
The development of non-viral vectors for the delivery of nucleic acids into cells necessitates molecules that can associate with nucleic acids to allow these large, hydrophilic polyanions to cross the cell membrane, which is a hydrophobic, negatively charged barrier of a phospholipid bilayer, help them to escape from lysosomal degradation and facilitate their entry into the nucleus. Expression of the gene of interest also depends on the accessibility of the delivered nucleic acid to the cellular transcription machinery, most likely necessitating dissociation of the complexes.
Although having been described as early as 1965 (Bangham et al., J. Mol. Biol. 13:238-252, 1965), liposomes, which can encapsulate molecules of interest for delivery to -he cell, did not reach the marketplace as injectable therapeutics in humans until the 1990s (Gregoriadis, Trends in Biotechnol. 13:527-537, 1995). This delay is attributable to difficulties in obtaining reproducible formulations with acceptable stabilities. A major breakthrough was the development of "sterically stabilized (stealth) liposomes" which contained a certain percentage of polyethyleneglycol (PEG)-modified phospholipids (PEG-PLs) (Gregoriadis, Trends in Biotechnol. 13:527-537, 1995; Lasic, Angew. Chem. Int. Ed. Engl. 33:1685-1698, 1994). These PEG-PL containing liposomes proved to be more successful in evading detection and elimination by the reticulo-endothelial system, which resulted in greatly enhanced circulation half-lives. While (PEG)-modified liposomes have been most widely used, other hydrophilic polymers such as poly(vinyl pyrrolidone) which augment the stability of liposomes when grafted on their surface have been described (Torchilin, V. P. et al., Biochim. Biophys. Acta 1195:181-184, 1994).
Progress in lipid-mediated nucleic acid transfer into cells was advanced with the introduction of cationic lipids as vehicles for the transfer of nucleic acids into cells (Felgner et al., Proc. Natl. Acad. Sci. 84:7413-7417, 1987; Behr et al., Proc. Natl. Acad. Sci. 86:6982-6986, 1989; Gao et al., Biochem. Biophys. Res. Communic. 179:280-285, 1991; Behr, Bioconjugate Chemistry 5:382-389, 1994; Fahrhood et al., Annals New York Academy of Sciences 716:23-35, 1994; Ledley, Human Gene Therapy 6:1129-1144, 1995). Because cationic lipids are positively charged, they are able to complex with negatively charged nucleic acids. Unlike liposomes, these complexes do not require an encapsulation step and are prepared by simple mixing of components. The complexes essentially comprise of lipid-coated nucleic acid, in which the positively charged coat of the complex neutralizes the negative charges of the nucleic acid and, also, can efficiently bind to the negatively charged cell surface, facilitating entry of nucleic acid into the cell (Farhood et al., Annals N.Y. Acad. Sci. 716:23-35, 1994).
The advantages of using cationic lipids to mediate transfection of nucleic acids include the simplicity of preparation of the complexes, the ability of the lipid component to complex most of the nucleic acid, a wide range of cell types amenable to transfection, a high efficiency of transfer, lack of immunogenicity of the complexes and availability of the cationic lipids through chemical synthesis (Farhood et al., Annals N.Y. Acad. Sci. 716:23-35, 1994).
Cationic lipid-mediated delivery of nucleic acid to a wide variety of cell types has been demonstrated in vitro and in vivo. For example, nucleic acid encoding the cystic fibrosis transmembrane conductance regulator (CFTR) complexed with cationic lipids has been delivered to mouse lungs by intratracheal installation (Yoshimura et al., Nucleic Acids Res. 20:3233-3240, 1992) or by aerosol delivery (Stribling et al., Proc. Natl. Acad. Sci. 89:11277-1281, 1992). The delivery of CFTR using cationic lipids to a mouse model of cystic fibrosis (CF) produced correction of the ion channel defect (Hyde et al., Nature 362:250-255, 1993). Human clinical studies with cationic lipid-mediated delivery of the CFTR gene to CF patients demonstrated expression of the gene in nasal epithelium and no adverse clinical effects (Caplen et al., Nature Medicine 1:39-46, 1995).
Systemic gene expression of a reporter gene following a single intravenous injection of a cationic lipid-DNA complex has been shown in mice (Zhu et al., Science 261: 209-211, 1993). Moreover, safety studies in rodents and non-human primates of systemically administered cationic lipid-nucleic acid complexes have shown no significant toxicity associated with administering such complexes (Parker et al., Human Gene Therapy 6:575-590, 1995).
Cationic lipid-mediated transfection of mRNA in tissue culture was demonstrated to lead to translation of the transcript (Malone et al., Proc. Natl. Acad. Sci. 86:6077-6081, 1989). Delivery of antisense oligonucleotides to human endothelial cells using cationic lipids provided increased cellular uptake of the oligonucleotides and increased activity thereof in the cells (Bennett et al., Mol. Pharm. 41:1023-1033, 1992). The use of cationic lipids complexed to retroviral particles has allowed viral infection of cells which lacked the appropriate virus receptor (Innes et al., J. Virol. 64:957-962, 1990) or enhanced retroviral transduction using complexes known as virosomes (Hodgson et al., Nature Biotechnol. 14:339-342, 1996).
Immunotherapy for cancer using cationic lipid-nucleic acid complexes containing major histocompatibility (MHC) genes directly injected into mice tumors elicited immune responses that resulted in tumor regression (Plautz et al., Proc. Natl. Acad. Sci. 90:4645-4649, 1993).
Human clinical studies are currently underway using cationic lipid-mediated delivery of DNA sequences encoding immunotherapeutic molecules in human melanoma, colorectal and renal cancer patients (Nabel et al., Proc. Natl. Acad. Sci. 90:11307-11311, 1993; Crystal, Science 270:404-410, 1995).
The cationic lipid formulations to date have often incorporated the phospholipid dioleoylphosphatidylethanolamine (DOPE). This phospholipid is thought to disrupt the endosomal membrane by destabilizing its bilayer structure, allowing the lipid-nucleic acid complex to escape endosomal degradation and to enter into the cytoplasm (Farhood et al., Biochem. Biophys. Acta 1235:289-295, 1995).
However, a significant obstacle in the widespread use of cationic lipid complexes for nucleic acid delivery to cells is the tendency of the complexes to form large aggregates in solution. | {
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The present invention relates to an electrical circuit for automatically controlling an input current to a current translating device having an output current functionally related to the input current.
Current translating devices, such as current mirrors, current transducers, opto-couplers, and the like, produce an output current that is functionally related to an input current. The functional relationship between the input and output currents of these devices can be defined as a current-transfer ratio wherein a given amount of input current produces a proportional amount of output current. Knowing the current-transfer ratio for a particular type of current translating device permits the design of control circuits that establish the input current level and correspondingly the output current level for the device. However, the current-transfer ratios of similar types of devices can vary over a wide range due to variation in the electrical characteristics of the individual elements making up the device. Additionally, the current-transfer ratio of a given device can vary over time due to changes in temperature, degradation of the device, and so forth. Further, it is desirable in some applications to controllably change the current-transfer ratio of a device to produce a variable current output.
An opto-coupler is an example of a current translating device that exhibits the above described characteristics. An opto-coupler is generally composed of a light source, such as a light-emitting diode (LED), and an opto-receiver, such as a phototransistor. The current input to the LED produces a radiating light output from the LED that is coupled to the phototransistor. A current output is produced by the phototransistor in response to the light intensity from the LED which is controlled by its current input. As previously stated, the individual components of a current-translating device, in this case an optocoupler, have a wide range of electrical characteristics which results in a wide range of current-transfer ratios. It is for this reason that an adjustable control circuit is required for establishing the input current level to the opto-coupler based on its current-transfer ratio. In addition, the current-transfer ratio of the opto-coupler can change if foreign material collects on the LED or the phototransistor and diffuses the light.
A circuit is needed for use with a current translating device having a wide range of current transfer ratios that automatically controls the input current to the device so that the proper, functionally related output current is produced. | {
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Laterally double-diffused-metal-oxide semiconductor (LDMOS) transistors have the characteristics of high break-down voltage, and compatibility with the complimentary MOS process; and have been widely used in power integrated circuits (ICs). Conventional MOS devices include source and drain that are symmetrical with respect to a gate structure, while, in a LDMOS transistor, the distance between the drain and the gate structure is greater than the distance between the source and the gate structure. Specifically, there is a relatively long lightly-doped region between the drain and the gate structure of the LDMOS transistor. Such a path is referred to as a drift region. When a high voltage is applied to the drain of the LDMOS device, the drift region is used to sustain a relatively high potential to obtain a relatively high breakdown voltage (BV).
The drive current (Ion) and the breakdown voltage are the two important parameters to evaluate the electrical properties of the LDMOS devices. The drive current refers to the current flowing from the drain to the source of the LDMOS device when the LDMOS device is in operation. The breakdown voltage refers to the maximum transient threshold voltage of a targeted terminal of the LDMOS device before the LDMOS device is broken down. A relatively large drive current and a relatively large breakdown voltage enable the LDMOS device to have a desired switching characteristic and a relatively strong drive ability.
However, it is desirable to improve the electrical properties of conventional LDMOS devices. The disclosed methods and semiconductor structures are directed to solve one or more problems set forth above and other problems in the art. | {
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This invention relates to laser systems and in particular to multi-wavelength laser systems.
Use of lasers for medical purposes is well established. Lasers are used extensively for cosmetic purposes such as hair removal, vein treatment, skin rejuvenation, treatment of telangeatesia and treatment of port wine stain. Each of these treatments is preferably performed with a laser producing laser pulses at a wavelength chosen to be most effective for the particular treatment. For example, a Nd:YAG laser operating at 1064 nm may be used for hair removal and certain types of vein treatment. A Nd:YAG laser operating at 1320 nm may be used for skin rejuvenation and micro skin surgery. Treatment of port wine stains is usually performed using a dye laser operating at a wavelength of 577 nm. Lasers used for treatment of small surface veins do not work very well for treatment of larger deeper veins. As a consequence a medical facility offering a variety of laser-based cosmetic services in the past has been required to acquire and maintain several separate laser systems. This is expensive.
Some wavelengths are very preferentially absorbed in a particular type of tissue such as when the tissue contains a particular chromophore that has a peak or reletively high absorption at the particular wavelength. Use of a laser beam matched to a peak or relatively high absorption in tissue to treat the tissue is referred to as xe2x80x9cselective thermolysisxe2x80x9d. Some wavelengths are absorbed relatively uniformly in tissue and when these wavelengths are used to treat the tissue it is referred to as xe2x80x9cnon-selective thermolysisxe2x80x9d.
What is needed is a single laser that can produce simultaneously laser light at a variety of wavelengths needed in medical facilities specializing is cosmetic care.
The present invention provides a single laser system that operates at any one or any combination of at least five wavelengths each of which are important to medical facilities offering laser cosmetic services. It includes appropriate laser optics and a crystal rod configured to produce a first pulsed laser beam, and appropriate laser optics and a second crystal rod configured to produce a second pulsed laser beam. Both rods are pumped simultaneously preferably from the same pump source. Beams from each of these lasers are frequency doubled using frequency-doubling crystals to produce third and fourth laser beams. The frequencies of the first and second beams are also combined in a sum frequency generating crystal to produce a fifth laser beam. In a preferred embodiment the first and second laser beams are produced using YAP:Nd crystals with wavelengths of 1079 nm and 1341 nm. The third and fourth laser beams at 539.5 nm and 670.5 nm are produced using KTP frequency doubling crystals and the fifth laser beam at about 598 nm is produced using a KTA sum frequency crystal. Thus, five different beams are produced with this laser system. All or any combination of these five beams are preferably combined by coupling them into a single optical fiber so that the beam can be easily transmitted to the place of treatment. | {
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Systems employing data storage elements include, for example, video cameras and image displays. Such systems employ an addressing structure that provides data to or retrieves data from the storage elements. One system of this type to which one embodiment of the present invention is particularly directed is a general purpose flat panel display, whose storage or display elements store light pattern data. A flat panel display comprises multiple display elements distributed throughout the viewing area of a display surface. A flat panel display system is desirable because it does not necessarily require a cathode-ray tube to develop a display image. A cathode-ray tube is undesirable because of its size, fragility, and need for high voltage drive circuitry.
One type of flat panel display system employs an addressing structure that accomplishes direct multiplexing of multiple liquid crystal cells or display elements arranged in an array. Each of the liquid crystal cells is positioned between a pair of electrical conductors that selectively apply select and deselect voltage signals across the liquid crystal cell to change its optical properties and thereby change the brightness of the image it develops. A display system of this type is characterized as "passive" because no "active" electronic device cooperates with the liquid crystal cell to modify its electro-optical properties. Such a display system suffers from the disadvantage of being capable of implementation with only a limited number of addressable lines (i.e., up to about 250) of video information or data for developing a display image.
One expedient for increasing the number of addressable lines of data in a liquid crystal display system entails the use of an addressing structure in which a separate electronic device cooperates with each liquid crystal cell to increase the effective nonlinearity of its electro-optic response to the select and deselect voltage signals. Some of what are referred to as "two-terminal" device addressing techniques can be characterized in this way. Although increasing the effective nonlinearity of a display element may allow greater multiplexing capabilities in a bilevel display, there remain many difficulties with this technique in respect to achieving gray scale performance.
The objective in designing liquid crystal matrix display systems having full gray scale capability is to provide an addressing structure that does not rely on obtaining the nonlinearity function from the liquid crystal material. An addressing structure that uses a matrix of electrically "active" elements accomplishes this objective by employing at each picture element an electronic switch that is separate from the liquid crystal material. The active matrix uses two- or three-terminal solid state devices in association with each liquid crystal cell to develop the needed nonlinearity and display element isolation. Addressing structures constructed of two-terminal devices can employ diodes of various types, and addressing structures constructed of three-terminal devices can employ thin film transistors (TFT) of various types manufactured from different semiconductor materials.
One problem with two- and three-terminal active matrices is that the very large number of active devices makes it very difficult to fabricate the matrix in large quantities with high production yields. Another problem, which is characteristic of TFT devices, is the difficulty of constructing thin film transistors with sufficiently high "off resistances." A relatively low "off resistance" provides a display element that may not hold the charge developed across it for the requisite time. A relatively low "off resistance" also decreases the "off resistance" to "on resistance" ratio, which preferably exceeds 10.sup.6 to promote proper operation of the TFT matrix. TFT matrices sometimes employ a separate storage capacitor with each display element to offset the effect of an insufficiently high "off resistance." The use of separate storage capacitors increases, however, the complexity of the TFT matrix incorporating them and the likelihood of decreased production yields. One other possible problem with a TFT active matrix is that the size of a TFT can be relatively large compared to that of the display element because "on" current requirements tend to increase the dimensions of a TFT device. This may affect the light efficiency of the device.
An active matrix formed of TFT devices is capable of developing black-and-white and colored images. To develop colored images, the active matrix employs a color filter containing multiple groups of spots in different colors spatially aligned with the display elements. A group of display elements aligned with spots of different colors would, therefore, define a single image pixel.
Flat panel display systems can also be implemented with display elements employing an ionizable gas or plasma that glows to produce on a display surface luminous regions whose color is characteristic of the type of gas used. The luminous regions are selectively activated to form a display image.
Another type of flat panel display system employs a plasma to generate electrons that are accelerated to strike a phosphor and produce a luminescent spot. Such a flat panel display provides increased efficiency in brightness but is difficult to produce with large display areas and requires complex drive circuits. Such flat panel displays can be constructed with multiple electron-excited phosphors having different spectral characteristics to provide multi-colored images.
Problems with gas-plasma flat panel displays are purportedly alleviated through the use of gas-discharge displays of the plasma-sac type. In such displays, a plasma-sac produced on the cathode side of an apertured insulator moves from one aperture to another to effect a raster-type scan. The plasma-sac-type gas-discharge displays are also complex to fabricate and are susceptible to low production yields. | {
"pile_set_name": "USPTO Backgrounds"
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Straight-chain olefins each having one double bond in the molecule thereof are useful as basic chemical raw materials in the petrochemical industry, and the uses thereof differ depending on the positions of the double bonds in the molecules thereof. Internal olefins having a double bond internally are used as reaction raw materials of reactions such as hydrogenation and alkylation. Meanwhile, terminal olefins having a double bond terminally are used for reactions such as dehydrogenation, hydroformylation and oligomerization. Terminal olefins of C4 to C8 used with ethylene as comonomers among terminal olefins when linear low density polyethylene (LLDPE) is produced (for example, 1-butene, 1-hexene, and 1-octane) is economically important, in particular. Additionally, 1-butene is used also for producing butadiene, 1-polybutene, and buteneoxide.
Straight-chain olefins having a double bond terminally (for example, 1-butene) can be produced, for example, by isomerizing straight-chain olefins having a double bond internally and corresponding thereto (for example, 2-butene) by catalysts.
For example, catalytic reactions in which straight-chain olefins having an internal double bond are isomerized to straight-chain olefins having a terminal double bond are disclosed in Patent Literature 1 to 5. | {
"pile_set_name": "USPTO Backgrounds"
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Zirconium Phosphate (ZrP) is used during sorbent dialysis to absorb ammonium ions generated by the reaction of urease breaking down urea in dialyzed blood. The ZrP layer is oftentimes provided as a specific layer in a sorbent cartridge used during dialysis. However, urease is generally not expended before ZrP is exhausted during dialysis. As such, if a patient has a large amount of urea in the blood, which generates a large amount of ammonia from urease, the ZrP layer may not be able to adsorb all the ammonia generated by the urea. In that case, a sorbent cartridge's capacity to adsorb ammonia has been reached resulting in so-called “ammonia breakthrough.” Ammonia may then enter the dialysate fluid, which is returned to the patient. Because ammonia is toxic, dialysis must be halted and the cartridge replaced.
In order to avoid ammonia breakthrough during therapy, oftentimes more zirconium phosphate is provided than is normally necessary, thereby ensuring that almost all patients can receive therapy without ammonia breakthrough. This provides enough zirconium phosphate for the majority of patients, but increases costs and waste by using more of the zirconium phosphate than is necessary.
Known dialysate fluid circulation systems and apparatuses have systems in place to halt dialysis in the event of ammonia breakthrough. In other systems, additional zirconium phosphate may be added in order to continue dialysis. An alternative to stopping dialysis involves bypassing a module containing urease, and thereby stopping the process of creating ammonia. However, although other toxins can continue to be removed from the patient, urea is no longer removed from the dialysate. In order to minimize the frequency of ammonia breakthrough, some sorbent cartridges use more zirconium phosphate than is necessary for most patients. This allows dialysis to continue as normal for larger or more uremic patients. However, providing more zirconium phosphate than is necessary for most patients results in increased costs and waste along with larger and more cumbersome cartridges. Customizing sorbent cartridges for larger or more uremic patients likewise increases costs. Alternatively, expensive sorbent materials have been used to remove ammonia from spent dialysate. However, the systems do not provide for recharging some or all of the components of a sorbent cartridge that would allow reuse of specific components to enable lower long-term costs for operating such systems.
As such, there is a need for removing urea without halting dialysis or risking harm to a patient in the event of ammonia breakthrough. There is also a need for improving the effectiveness and efficiency of a sorbent cartridge by reducing the amount of expensive, rate-limiting sorbent materials used during dialysis. There is a need for avoiding ammonia breakthrough during therapy without providing more zirconium phosphate than is required while ensuring that almost all patients can receive therapy without ammonia breakthrough. There is a need for avoiding increased costs and waste by avoiding using more of the zirconium phosphate than is necessary for safe dialysis. There is a further need for a sorbent cartridge and related systems and methods having a reserve module containing a sorbent material capable of removing ammonia from dialysate so that dialysis can continue in the event of ammonia breakthrough. There is a need for a sorbent cartridge providing for the use of a reserve sorbent module to allow normal operation with a smaller amount of sorbent material, while at the same time ensuring that ammonia breakthrough does not occur. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to a Raman amplifier that amplifies a wavelength division multiplexed (WDM) signal by utilizing a Raman effect, a WDM optical communication system, and a method for controlling Raman amplification, and in particular, relates to technology for controlling pumping light in order to realize the Raman amplification coping with variations in system operating conditions.
2. Description of the Related Art
A WDM optical communication method that multiplexes optical signals having different wavelengths to transmit them in a single optical fiber is an effective means for realizing a more economical optical communication system of larger capacity as well as a flexible optical network. Particularly, as technology with regard to optical amplifiers has been developed in recent years, the WDM optical communication method becomes in practical use rapidly as backbone technology supporting the Internet service.
The WDM optical communication system enables long-distance transmission mainly by repeating signal light while amplifying it in a repeater stage using optical amplification repeating technology. As an optical amplifying means in such a WDM optical communication system, there are used a rare-earth element doped optical fiber amplifier, a Raman amplifier, and so on.
With regard to the Raman amplifier mentioned above, two amplification types are known: that is, a distributed parameter type and a concentrated type. The distributed parameter type is an amplification type in that pumping light is introduced into a transmission path (for example, a silica-based optical fiber and the like) of an optical communication system, to Raman amplify in a distributing manner signal light being propagated through the transmission path, so that a part of loss that occurs when the signal light passes through the transmission path can be compensated. On the other hand, the concentrated type is an amplification type in that the pumping light is introduced in a concentrated manner into an optical fiber having a small effective cross-sectional area, for example, and high non-linearity for Raman amplification.
The Raman amplification of both of the distributed parameter type and the concentrated type described above shows amplification characteristics having a gain peak at a frequency lower than the frequency of the pumping light by a Raman shift amount (for example, 13.2 THz in the case of silica-based medium). Therefore, it is possible to amplify signal light of an arbitrary wavelength by preparing a pumping light source of an appropriate pumping light wavelength in consideration of the shift frequency of the Raman gain, and it is also possible to Raman amplify WDM signal light having wider bandwidth arbitrarily by combining a plurality of pumping light of different wavelengths. Further, by changing a distribution ratio of pumping light power of each of the wavelengths, a profile of the Raman gain corresponding to each pumping light wavelength may also be changed so that wavelength dependence of the Raman amplified WDM signal light can be adjusted arbitrarily.
By the way, in the optical network system of next generation, for example, it is anticipated that operating conditions of the system such as a wavelength band of the WDM signal light and the number of signal light, a signal light level input to an optical transmission path, a type of the optical transmission path and the like may be changed dynamically. However, in the previously proposed technology regarding the Raman amplification, there is a problem in that it is difficult to flexibly cope with the dynamic change of the system operating conditions described above.
More specifically, for example, if the operating conditions are changed such that so-called S-band (a wavelength band of 1480 nm-1520 nm) is added to WDM signal light using C-band (a wavelength band of 1525 nm-1565 nm) and L-band (a wavelength band of 1570 nm-1620 nm), since most of the conventional Raman amplifiers have been designed individually corresponding to each band, it is possible to cope with a change of operating wavelength in one band by controlling the power, wavelength and the like of the pumping light, but it is difficult to cope with such a dynamic change across a plurality of bands using a single type of Raman amplifier.
Further, when the signal light of S-band is added as described above in order to achieve the wider bandwidth of WDM signal light, there is a possibility that a wavelength of pumping light used before the change of the operating conditions may coincide with or considerably approximate to a wavelength of the added S-band signal light, resulting in a problem in degradation of transmission quality of the WDM signal light.
Still further, it is anticipated that the dynamic change of the operating conditions described above is practically carried out in stepwise along with the lapse of required time. In such a case, it is important to cope with the change of the operating conditions without affecting the service in operation. Therefore, it is necessary to establish controlling technology for optimizing a gain and gain wavelength characteristics of the Raman amplification in response to the change with time of the operating conditions. | {
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1. Field of the Invention
The present invention relates to transistors and particularly to transistors utilizing field plates.
2. Description of the Related Art
High electron mobility transistors (HEMTs) are a common type of solid state transistor that are regularly fabricated from semiconductor materials such as Silicon (Si) or Gallium Arsenide (GaAs). One disadvantage of Si is that it has low electron mobility (600-1450 cm2/V-s), which produces a high source resistance. This resistance can degrade the Si based HEMT's high performance gain. [CRC Press, The Electrical Engineering Handbook, Second Edition, Dorf, p. 994, (1997)]
GaAs based HEMTs have become the standard for signal amplification in civil and military radar, handset cellular, and satellite communications. GaAs has a higher electron mobility (approximately 6000 cm2/V-s) and a lower source resistance than Si, which allows GaAs based devices to function at higher frequencies. However, GaAs has a relatively small bandgap (1.42 eV at room temperature) and relatively small breakdown voltage, which prevents GaAs based HEMTs from providing high power at high frequencies.
Improvements in the manufacturing of wide bandgap semiconductor materials such as AlGaN/GaN, has focused interest on the development of AlGaN/GaN HEMTs for high frequency, high temperature and high power applications. AlGaN/GaN has large bandgaps, as well as high peak and saturation electron velocity values [B. Belmont, K. Kim and M. Shur, J. Appl. Phys. 74, 1818 (1993)]. AlGaN/GaN HEMTs can also have two dimensional electron gas (2DEG) sheet densities in excess of 1013/cm2 and relatively high electron mobility (up to 2019 cm2/Vs) [R. Gaska, J. W. Yang, A. Osinsky, Q. Chen, M. A. Khan, A. O. Orlov, G. L. Snider and M. S. Shur, Appl. Phys. Lett., 72, 707 (1998)]. These characteristics allow AlGaN/GaN HEMTs to provide very high voltage and high power operation at RF, microwave and millimeter wave frequencies.
AlGaN/GaN HEMTs have been grown on sapphire substrates and have shown a power density of 4.6 W/mm and a total power of 7.6 W [Y. F. Wu et al., IEICE Trans. Electron., E-82-C, 1895 (1999)]. More recently, AlGaN/GaN HEMTs grown on SiC have shown a power density of 9.8 W/mm at 8 GHz [Y. F. Wu, D. Kapolnek, J. P. Ibbetson, P. Parikh, B. P. Keller and U. K. Mishra, IEEE Trans. Electron. Dev., 48, 586 (2001)] and a total output power of 22.9 at 9 GHz [M. Micovic, A Kurdoghlian, P. Janke, P. Hashimoto, D. W. S. Wong, J. S. Moon, L. McCray and C. Nguyen, IEEE Trans. Electron. Dev., 48, 591 (2001)].
U.S. Pat. No. 5,192,987 to Khan et al. discloses GaN/AlGaN based HEMTs grown on a buffer and a substrate. Other AlGaN/GaN HEMTs and field effect transistors (FETs) have been described by Gaska et al., “High-Temperature Performance of AlGaN/GaN HFET's on SiC Substrates,” IEEE Electron Device Letters, Vol. 18, No 10, October 1997, Page 492; and Ping et al., “DC and Microwave Performance of High Current AlGaN Heterostructure Field Effect Transistors Grown on P-type SiC Substrates,” IEEE Electron Devices Letters, Vol. 19, No. 2, February 1998, Page 54. Some of these devices have shown a gain-bandwidth product (fT) as high as 67 gigahertz [K. Chu et al. WOCSEMMAD, Monterey, Calif. (February 1998)] and high power densities up to 2.84 W/mm at 10 GHz [G. Sullivan et al., “High Power 10-GHz Operation of AlGaN HFET's in Insulating SiC,” IEEE Electron Device Letters, Vol. 19, No. 6, Page 198 (June 1998); and Wu et al., IEEE Electron Device Letters, Volume 19, No. 2, Page 50 (February 1998)].
Electron trapping and the resulting difference between DC and RF characteristics have been a limiting factor in the performance of GaN based transistors, such as AlGaN/GaN HEMTs. Silicon Nitride (SiN) passivation has been successfully employed to alleviate this trapping problem, which has resulted in high performance devices with power densities over 10 W/mm at 10 Ghz. U.S. Pat. No. 6,586,781 discloses methods and structures for reducing the trapping effect in GaN-based transistors. However, due to the high electric fields existing in these structures, charge trapping can still be an issue. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The invention relates to an electrical connector and, more particularly, to interaction between an electrical contact terminal and a housing of the connector.
2. Brief Description of Prior Developments
U.S. Pat. No. 7,229,324 discloses an electrical connector with a housing having V-shaped preload ridges provided with support extensions. U.S. Pat. No. 6,997,750 discloses a contact with a ferrite tube. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to a recording apparatus such as a printer, a copying machine, a word processor, a personal computer, a facsimile and the like. More particularly, it relates to a recording apparatus in which a recording sheet is pinched between and conveyed by a pinch roller and a convey roller and, after recording, the recording sheet is pinched between and discharged by a discharge roller and spur wheels.
2. Related Background Art
An example of conventional techniques with reference will be explained to FIG. 13, a pinch roller 5 is always urged against a recording sheet 3 or a convey roller 4. Further, a discharge roller 11 is selected to have a convey amount slightly greater than that of the convey roller 4 so that tension is applied to the recording sheet 3 to eliminate looseness of the recording sheet and permit the recording under a good condition. After the recording sheet 3 leaves the pinch roller 5, the recording sheet is discharged mainly by a conveying force of the discharge roller 11.
However, the above-mentioned conventional technique has the following disadvantages.
(1) When a trail end of the recording sheet 3 leaves the pinch roller 5, as shown in FIG. 4, the recording sheet is subjected to a force F directed toward a downstream direction and a downward direction, so that, since a convey distance of the recording sheet 3 is increased and conveying accuracy is worsened, recording accuracy at a rear end portion of the recording sheet 3 is worsened.
(2) After the trail end of the recording sheet 3 leaves the pinch roller 5, since the recording sheet is conveyed mainly by the discharge roller 11 and spur wheels 12 which are rotated faster than the convey roller 4, a convey distance of the recording sheet 3 per one line space is increased to worsen the conveying accuracy, thereby worsening the recording accuracy at the rear end portion of the recording sheet 3.
To eliminate the above-mentioned conventional drawbacks, the present invention provides a (first) recording apparatus comprising a recording portion for effecting the recording on a recording sheet, a convey means for conveying the recording sheet to the recording portion by pinching the recording sheet between a pinch roller and a convey roller, and a discharge means for discharging the recording sheet by pinching the recording sheet between a spur wheel and a discharge roller. It further comprises an urging means for urging the pinch roller against the recording sheet, an urging force controlling means for controlling an urging force of the urging means, and a detecting means for detecting the fact that a trail end of the recording sheet is conveyed up to a predetermined position disposed upstream of a position where the trail end of the recording sheet leaves the pinch roller, wherein the urging force controlling means reduces the urging force of the urging means on the basis of a detection result from the detecting means.
The present invention further provides a recording apparatus comprising a (second) recording portion for effecting the recording on a recording sheet, a convey means for conveying the recording sheet to the recording portion by pinching the recording sheet between a pinch roller and a convey roller, and a discharge means for discharging the recording sheet by pinching the recording sheet between a spur wheel and discharge roller. It further comprises an urging means for urging the pinch roller against the recording sheet, an urging force controlling means for controlling an urging force of the urging means, and a detecting means for detecting the fact that a trail end of the recording sheet is conveyed up to a predetermined position disposed upstream of a position where the trail end of the recording sheet leaves the pinch roller, wherein the urging force controlling means releases the urging force of the urging means on the basis of a detection result from the detecting means.
The present invention also provides a (third) recording apparatus comprising a recording portion for effecting the recording on a recording sheet, a convey means for conveying the recording sheet to the recording portion by pinching the recording sheet between a pinch roller and a convey roller, and a discharge means for discharging the recording sheet by pinching the recording sheet between a spur wheel and a discharge roller. It further comprises a rotation controlling means for controlling rotations of the convey roller and the discharge roller, and a detecting means for detecting the fact that a trail end of the recording sheet is conveyed up to a predetermined position disposed upstream of a position where the trail end of the recording sheet leaves the pinch roller, wherein the rotation controlling means reduces convey amounts of the convey roller and the discharge roller corresponding to one line space.
The present invention further provides a (fourth) recording apparatus comprising a recording portion for effecting the recording on a recording sheet, a convey means for conveying the recording sheet to the recording portion by pinching the recording sheet between a pinch roller and a convey roller, and a discharge means for discharging the recording sheet by pinching the recording sheet between a spur wheel and a discharge roller. It further comprises a rotation controlling means for controlling rotation of the discharge roller, and a detecting means for detecting the fact that a trail end of the recording sheet is conveyed up to a predetermined position disposed upstream of a position where the trail end of the recording sheet leaves the pinch roller, wherein the rotation controlling means reduces a convey amount of the discharge roller corresponding to one line space.
The first or second recording apparatus may further include a rotation controlling means for controlling rotation of the convey roller and the discharge roller so that the rotation controlling means reduces convey amounts of the convey roller and the discharge roller corresponding to one line space. Alternatively, the first or second recording apparatus may further include a rotation controlling means for controlling rotation of the discharge roller so that the rotation controlling means reduces convey amount of the discharge roller corresponding to one line space.
In the third recording apparatus, the rotation controlling means may set the convey amount of the discharge roller to become the same as a convey amount of the convey roller before detected by the detecting means. In the fourth recording apparatus, the rotation controlling means may set the convey amount of the discharge roller to become the same as a convey amount of the convey roller before detected by the detecting means.
When the first or second recording apparatus includes the rotation controlling means for controlling rotation of the convey roller and the discharge roller, the rotation controlling means may set the convey amount of the discharge roller to become the same as a convey amount of the convey roller before detected by the detecting means. When the first or second recording apparatus includes the rotation controlling means for controlling rotation of the discharge roller, the rotation controlling means may set the convey amount of the discharge roller to become the same as a convey amount of the convey roller before detected by the detecting means.
In any of the first to fourth recording apparatuses, the detection means may comprise a sensor disposed in the vicinity of the convey roller, and a rotation amount measuring means for measuring a rotation amount of the convey roller. In any of the first to fourth recording apparatuses, the recording portion may be of ink jet recording type in which the recording is effected by discharging ink in response to a signal.
In any of the first to fourth recording apparatuses, the recording portion may be of ink jet recording type in which the recording is effected by discharging ink by growth of a bubble formed by heating the ink to exceed the film-boiling temperature generated by energizing an electrical/thermal converter in response to a signal. | {
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In a product, speaker drivers are typically combined with enclosures. For example a wide range of electronic devices, such as desktop computer, laptop computer, tablet, and smartphone, have built-in speaker drivers. A driver may as well be mounted onto its own dedicated cabinet box, creating a standalone speaker product. Examples for this are the typical Hi-Fi or stereo loudspeakers which are part of a home Hi-Fi system or professional sound reinforcement systems typically used in concert venues. Other examples of drivers which are mounted onto enclosures are headphones, car stereo systems, and TV screens.
Buzzing sounds caused by the enclosure, the driver itself or a combination of the two is a common issue that arises when the driver is operating at considerable levels. In this disclosure, a “buzz” is considered to be an acoustic disturbance that is produced in large part due to a resonating mechanical component. The resonance is excited by an audio signal. When the resonance frequency of a mechanical component matches with an audio frequency component in the audio signal, the mechanical component experiences its largest amplitude of vibration. If the amplitude is large enough to cause one vibrating mechanical component to touch another component, a buzzing sound is produced. Additionally, even without a component actually touching other components, a component can emit a buzz which is simply caused by high-energy excitation that produces sound.
In a simplified model, music can be viewed as a sequence of harmonic partial tones. A harmonic partial tone of an audio signal is a frequency component of the audio signal that is an integer multiple of the fundamental frequency. For example, if the fundamental frequency is f, the harmonic partial tones have frequencies 2f, 3f, 4f . . . etc. The partial tones change over time with respect to their count, level and frequency. The majority of the energy of a musical signal is stored in its partial tones. This also holds for speech and animal sounds. Concentrating the energy of a communication signal (such as speech, music or animal sounds) into a few partial tones rather than spreading it over a large number of partial tones or a wider frequency spectrum is an energy efficient method of delivering a message across a noisy environment. In this disclosure, the terms “harmonic partial tone” and “partial tone” are used interchangeably.
In the case where music, speech or the like is being played back over a driver which is mounted on an enclosure whose structural resonances match with partial tones and the sound playback level is beyond a certain threshold, buzz is created. A buzz can however be masked by other components of the audio signal in which case they are not audible to a human being and therefore of little concern. On the other hand, if not masked, buzzes are very annoying.
A traditional way of mitigating the buzz problem is to apply changes to the physical structure of the enclosure. There are limits imposed by unit cost, weight, and product design however, often rendering a complete physical modifications-based elimination of buzzes unfeasible. If buzzes cannot be eliminated by the physical design, an audio signal processing approach referred to as equalization is commonly used, to reduce the levels of the frequency ranges that cause buzz. | {
"pile_set_name": "USPTO Backgrounds"
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Nuclear factor κB (“NF-κB”) is a family of inducible transcription factors controlling expression of genes that play important roles in airway inflammation and other inflammatory conditions and diseases, atherosclerosis, blood pressure, and immune response.
Under normal conditions, the NF-κB complex is inactivated in the cytoplasm by binding inhibitors of NF-κB. These inhibitors of NF-κB are referred to as “IκB”. Upon cellular stimulation, for example, with angiotensin II, oxidized low-density lipoproteins, cytokines, or viral pathogens, IκB is phosphorylated and degraded, liberating NF-κB, which enters the nucleus and activates the expression of target genes.
IκB Kinase (“IKK”) is a multisubunit complex that transduces upstream activating signals into the rate-limiting phosphorylation of IκB. More particularly, IKK is composed of 10-12 proteins whose composition is largely unknown. These proteins include catalytic kinases, such as IKKα and IKKβ; regulatory proteins, such as NF-κB essential modulator, which is sometimes referred to as “NEMO”, and IKKγ; and scaffolding proteins, such as IKAP.
Several studies have demonstrated that IKK is required for NF-κB activation. For example, one such study demonstrated that specific peptide inhibitors of IKK block inflammation in mice challenged with lipopolysaccharide (“LPS”).
In view of the above, a need remains for methods and products which can modulate NF-κB activation and, thus, which can be used in the treatment, prevention, or management of inflammatory conditions and diseases and of other conditions, diseases, and processes in which activated NF-κB plays a direct or indirect role. The present invention is directed, in part, to addressing this need. | {
"pile_set_name": "USPTO Backgrounds"
} |
The field of the present invention is portable chairs, particularly foldable or collapsible portable chairs.
Although portable chairs have long been known, a constant concern has been to construct portable chairs that are comfortable and durable, yet are capable of being easily compacted into minimal space and then readily reassembled. Various attempts towards this end are the following:
U.S. Pat. No. 2,564,915 to Nelson PA0 U.S. Pat. No. 3,695,702 to Ingellis PA0 U.S. Pat. No. 4,514,009 to Vanderminden et al.
As is true with other known collapsible or portable chairs, these devices may function adequately well, but they are each deficient in one or more respects. First, most portable chairs are only minimally compactable. Typically a "portable" chair continues to be unwieldy and to provide storage problems even in its folded or compacted position. Those chairs that thoroughly collapse usually provide a plethora of separate pieces which are easily misplaced and create an undesired challenge for reassembly. Second, many folding chairs are uncomfortable and are limited by little or no adjustability.
To some extent the collapsibility of portable chairs has been constrained by the types of hinges available. As a practical matter, in order to repeatedly fold a chair, flexible hinges must be employed that accept pivoting in more than one plane of movement; however, such hinges must be capable of being locked into position once the chair is fully assembled. Examples of previous attempts, to create locking hinges are U.S. Pat. No. 1,036,222 to Griffenberg and U.S. Pat. No. 4,160,607 to Reichon. Although these devices may function well in their particular applications, they do not solve the problems found in creating a fully collapsible folding chair. The hinge required in a fully collapsing portable chair needs to be quite flexible in the open position and strong enough to withstand the stresses of repeated distortions, yet resistant to all movement when in the locked position.
It is therefore an object of the present invention to provide a flexible locking hinge which can withstand the stresses inherent in fully collapsing a portable chair, yet provide a secure, unified structure when locked.
It is another object of the present invention to provide a portable chair that readily and thoroughly collapses into a compact easily transportable and storable single unit that is quickly and easily reassembled.
It is a further object of the present invention to provide a portable chair that is comfortable and allows for a full range of adjustability, from upright sitting to fully reclining positions. | {
"pile_set_name": "USPTO Backgrounds"
} |
The growth of the Internet has helped create a network of networks that link together billions of devices worldwide. Conventionally, the fastest and most reliable networks are built with custom application-specific integrated circuits (ASICs) and purpose-built hardware. As a result, large enterprise networks often resemble complex, monolithic systems. In such types of custom systems, adding features ad hoc and making changes to these systems while ensuring that the network does not experience any interruptions is very challenging.
Due to recent network focused advancements in commodity computing hardware, services that were previously only capable of being delivered by proprietary, application-specific hardware can now be provided using software running on commodity hardware by utilizing standard information technology (IT) virtualization techniques that run on high-volume server, switch, and storage hardware to virtualize network functions. By leveraging standard IT virtualization technology to consolidate different types of network equipment onto commercial “off-the-shelf” high volume servers, switches, and storage, network functions such as network address translation (NAT), firewalling, intrusion detection, domain name service (DNS), load balancing, and caching (just to name a few) can be decoupled from propriety hardware and can instead be run in software. This virtualization of network functions on commodity hardware is sometimes referred to as Network Functions Virtualization (NFV).
In an effort to develop a fully virtualized infrastructure, leading service providers have come together and created the European Telecommunications Standards Institute (ETSI) Industry Specification Group (ISG) for Network Functions Virtualization (NFV). This group has helped create the architecture and associated requirements for virtualizing various functions within telecommunications networks. Benefits of Network Functions Virtualization include reduced capital expenditure (i.e., by reducing the need to purchase purpose-built hardware), operating expenditure (i.e., by reducing space, power, and cooling requirements), reduced time-to-market (i.e., accelerated deployment), improved flexibility to address constantly changing demands, etc.
It is within this context that the embodiments described herein arise. | {
"pile_set_name": "USPTO Backgrounds"
} |
The structure of the intervertebral disc disposed between the cervical bones in the human spine comprises a peripheral fibrous shroud (the annulus) which circumscribes a spheroid of flexibly deformable material (the nucleus). The nucleus comprises a hydrophilic, elastomeric cartilaginous substance that cushions and supports the separation between the bones while also permitting articulation of the two vertebral bones relative to one another to the extent such articulation is allowed by the other soft tissue and bony structures surrounding the disc. The additional bony structures that define pathways of motion in various modes include the posterior joints (the facets) and the lateral intervertebral joints (the unco-vertebral joints). Soft tissue components, such as ligaments and tendons, constrain the overall segmental motion as well.
Traumatic, genetic, and long term wearing phenomena contribute to the degeneration of the nucleus in the human spine. This degeneration of this critical disc material, from the hydrated, elastomeric material that supports the separation and flexibility of the vertebral bones, to a flattened and inflexible state, has profound effects on the mobility (instability and limited ranges of appropriate motion) of the segment, and can cause significant pain to the individual suffering from the condition. Although the specific causes of pain in patients suffering from degenerative disc disease of the cervical spine have not been definitively established, it has been recognized that pain may be the result of neurological implications (nerve fibers being compressed) and/or the subsequent degeneration of the surrounding tissues (the arthritic degeneration of the facet joints) as a result of their being overloaded.
Traditionally, the treatment of choice for physicians caring for patients who suffer from significant degeneration of the cervical intervertebral disc is to remove some, or all, of the damaged disc. In instances in which a sufficient portion of the intervertebral disc material is removed, or in which much of the necessary spacing between the vertebrae has been lost (significant subsidence), restoration of the intervertebral separation is required.
Unfortunately, until the advent of spine arthroplasty devices, the only methods known to surgeons to maintain the necessary disc height necessitated the immobilization of the segment. Immobilization is generally achieved by attaching metal plates to the anterior or posterior elements of the cervical spine, and the insertion of some osteoconductive material (autograft, allograft, or other porous material) between the adjacent vertebrae of the segment. This immobilization and insertion of osteoconductive material has been utilized in pursuit of a fusion of the bones, which is a procedure carried out on tens of thousands of pain suffering patients per year.
This sacrifice of mobility at the immobilized, or fused, segment, however, is not without consequences. It was traditionally held that the patient's surrounding joint segments would accommodate any additional articulation demanded of them during normal motion by virtue of the fused segment's immobility. While this is true over the short-term (provided only one, or at most two, segments have been fused), the effects of this increased range of articulation demanded of these adjacent segments has recently become a concern. Specifically, an increase in the frequency of returning patients who suffer from degeneration at adjacent levels has been reported.
Whether this increase in adjacent level deterioration is truly associated with rigid fusion, or if it is simply a matter of the individual patient's predisposition to degeneration is unknown. Either way, however, it is clear that a progressive fusion of a long sequence of vertebrae is undesirable from the perspective of the patient's quality of life as well as from the perspective of pushing a patient to undergo multiple operative procedures.
While spine arthroplasty has been developing in theory over the past several decades, and has even seen a number of early attempts in the lumbar spine show promising results, it is only recently that arthoplasty of the spine has become a truly realizable promise. The field of spine arthroplasty has several classes of devices. The most popular among these are: (a) the nucleus replacements, which are characterized by a flexible container filled with an elastomeric material that can mimic the healthy nucleus; and (b) the total disc replacements, which are designed with rigid endplates which house a mechanical articulating structure that attempts to mimic and promote the healthy segmental motion.
Among these solutions, the total disc replacements have begun to be regarded as the most probable long-term treatments for patients having moderate to severe lumbar disc degeneration. In the cervical spine, it is likely that these mechanical solutions will also become the treatment of choice.
It is an object of the invention to provide instrumentation and methods that enable surgeons to more accurately, easily, and efficiently implant fusion or non-fusion cervical disc replacement devices. Other objects of the invention not explicitly stated will be set forth and will be more clearly understood in conjunction with the descriptions of the preferred embodiments disclosed hereafter. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The invention relates to methods for transmission of signalling data in cellular telecommunication networks. Especially, the invention is related to such a method as specified in the preamble of the independent method claim. 2. Description of Related Art
The current concept of a signalling radio bearer in the UMTS system (universal mobile telecommunication system) defines that there is only one radio bearer for signalling traffic between the cellular network and a mobile communication means. Both the RRC (radio resource control) and higher protocol layers use the same radio bearer, i.e. the same RLC (radio link control) entity. In some implementations it is possible to have two RLC entities for signalling traffic, one entity for unacknowledged mode transfer and one entity for acknowledged mode transfer. However, there is currently no means to treat these entities separately for example for setup, reconfiguration or release. The signalling radio bearer, sometimes called the signalling link, is set up during the RRC connection establishment procedure. In some implementations, it is even possible that the radio bearer service is actually provided by the PDCP layer. In this case the PDCP will run in transparent mode for signalling traffic.
Higher layer messages, such as MM (mobility management) or CM (connection management) layer messages are carried between a mobile communication means and the network in a RRC DIRECT TRANSFER message payload. The protocol stack is illustrated in FIG. 1. FIG. 1 shows an example of a partial protocol stack of a circuit switched core network (CN) domain, which protocol stack comprises connection management (CM) and mobility management (MM) protocol layers, and an example of a protocol stack of a packet switched core network domain, which protocol stack comprises session management (SM) and packet switched domain mobility management (PMM) protocol layers. Both of these protocol stacks communicate with the RRC (radio resource control) layer, which handles the transmission of the higher layer protocol messages in a RRC DIRECT TRANSFER MESSAGE payload. The radio link control protocol can be set up to provide unacknowledged or acknowledged data transmission service. Each RLC instance is configured by RRC to operate in one of three modes: transparent mode (Tr), unacknowledged mode (UM) and acknowledged mode (AM). The transparent and unacknowledged mode are used by some of the RRC signalling procedures. Majority of RRC signalling procedures including the Direct Transfer procedure utilize acknowledged mode transfer. The service that the RLC layer provides to upper layers is called radio bearer (RB). A radio bearer with the corresponding Iu bearer comprises a radio access bearer (RAB).
The problems with the prior art solution used at the time of writing this patent application are mainly related to priority control of signalling traffic. A problem can arise for example in a case, when a very long higher layer message is passed to RLC layer which buffers the message, and when a time critical RRC message also needs to be sent. In this situation, the RLC layer transmits the buffered messages first before transmitting more recent messages, which results in a delay of the time critical RRC message. Currently there are no mechanisms allowing priorization of more recent messages over those messages waiting in RLC transmission buffer. It is also possible that higher layer signalling such as MM and CM will need some prioritization means between the various higher layer protocols.
At the time of writing this patent application, a requirement has recently been identified which may finally require that several signalling radio bearers can be set up so that different QoS (quality of service) parameters can be used for different types of signalling. One solution for this requirement has been proposed. According to this solution, MM and higher layer signalling is carried over the air interface like any user traffic, in a separate radio bearer. This solution creates some problems related to integrity control functionxe2x80x94which is defined as a RRC layer functionxe2x80x94and to the existing procedures in Iu interface.
FIG. 2 illustrates protocol stack configuration for signalling transfer according to a recently proposed solution. According to this solution, signalling traffic of MM and other higher layer protocols are transmitted directly using PDCP services. In this solution, only function that would be required from PDCP layer is the integrity protection. According to the solution, either one user plane radio bearer is used for all higher layer signalling protocols or a separate user plane radio bearer is allocated for each higher layer protocol stack. In the example of FIG. 2 each CN domain employs a different radio access bearer (RAB) for signalling between UE and each CN domain. According to this solution, priority control between MM and RRC messages can be handled in RLC/MAC using normal radio bearer/logical channel priority control mechanisms.
This proposal has some disadvantages. For example, the proposed solution increases the complexity of the MM and PMM protocol implementations, since primitive interfaces are needed not only for the RRC protocol, but for the PDCP protocol as well. The proposed solution would also be an addition to current PDCP functions and change radically the basic function of PDCP as a packet service dependent sublayer. This would add complexity to the implementations of the PDCP protocol. Further, since PDCP is only intended for transmission of user plane traffic, in the proposed solution UE-CN signalling would be treated like user plane traffic, which implies that some modifications will most probably be needed also to the current Iu interface specifications. Further, in the proposed solution integrity protection needs to be implemented in two places: in PDCP layer for MM and higher layer signalling and in RRC layer for RRC signalling. As a consequence, the complexity of PDCP protocol increases and an additional header field is needed in PDCP data payload data units (PDU), since the integrity function requires a counter value to be transmitted with each piece of integrity protected data for use by the integrity protection algorithm.
An object of the invention is to realize a signalling method, which alleviates the aforementioned problems of prior art. A further object of the invention is to provide a method for transmission of control signalling, which allows determining of quality of service levels for different signalling traffic streams.
A still further object of the invention is to provide the aforementioned objects of the invention, without adding complexity in the protocol layers above the RRC protocol layer.
The objects are reached by setting up at least two signalling radio bearers for transmission of signalling traffic, and specifying rules for routing of higher layer signalling to the signalling radio bearers.
The method according to the invention is characterized by that, which is specified in the characterizing part of the independent method claim. The network element according to the invention is characterized by that, which is specified in the characterizing part of the independent claim directed to a network element. The mobile communication means according to the invention is characterized by that, which is specified in the characterizing part of the independent claim directed to a mobile communication means. The dependent claims describe further advantageous embodiments of the invention.
According to the invention, at least two signalling radio bearers are set up for transmission of signalling traffic and the cellular network configures how the signalling of higher layer protocols is mapped to said signalling radio bearers. Multiple radio bearers can be allocated for transferring signalling traffic, but all higher layer signalling is in any case taken through the RRC protocol.
In the inventive method, MM and higher layer messages are sent using RRC DIRECT TRANSFER messages, but separate RLC entities can be set up for RRC DIRECT TRANSFER messages. In various embodiments of the invention, separate radio bearers can be set up for individual CN domains and/or upper layer protocols and/or for a group of RRC messages.
Routing of messages to signalling bearers can advantageously be performed on the basis of CN domain identity information contained in every RRC DIRECT TRANSFER data unit. In embodiments, in which separate radio bearers are set up for different upper layer protocols or different groups of upper layer protocols, the routing of RRC DIRECT TRANSFER data units is advantageously performed on the basis of examination of the contents of data units and interpreting, with which protocol each data unit is associated.
The inventive method provides integrity protection of MM and higher layer messages as a consequence of the transmission of the messages in RRC DIRECT TRANSFER messages. The inventive method allows controlling of priority between MM and higher layer messages and RRC messages in the radio interface by adjusting the QoS parameters of bearers used to transfer the messages. | {
"pile_set_name": "USPTO Backgrounds"
} |
Raman scattering generally refers to the inelastic scattering of photons. When light scatters from an atom or molecule, a fraction of the photons induces a transition to or from an excited state of the atom or molecule, which produces scattered photons having a different frequency from the frequency of incident photons. The frequencies of the Raman scattered photons are characteristic of the atoms or molecules from which the photons scatter, which permits spectral analysis to identify chemical analytes. However, the fraction of photons scattered by Raman scattering is generally small, e.g., about 1 per 107 elastically scattered photons, and methods for enhancing the signal associated with Raman scattering have been developed. In particular, Surface Enhanced Raman Scattering (SERS) enhances the Raman scattering through interactions of scattered photons with rough metal surfaces or nanoparticles. Such enhancement is believed to result from resonances in localized surface plasmons interacting with photons and analytes. Methods and systems for further enhancing the Raman scattering signal and/or improving chemical analysis based on Raman scattering are sought.
Use of the same reference symbols in different figures indicates similar or identical items. | {
"pile_set_name": "USPTO Backgrounds"
} |
With the increasing popularity of the Internet, there continues to be significant growth in services offered online: web banking allows customers to manage funds in their bank and brokerage accounts from a personal computer; various Internet payment systems, such as Yandex.money, Webmoney or PayPal, allow consumers to conveniently pay for goods and services from merchants from auction sites, etc. In addition, users run an ever increasing array of application software and save their important work product both locally on their personal computers, and on remote servers. Therefore, it is not surprising that there is also an ever increasing number of malicious applications intended to steal, extort and spy on important data.
In order to combat malicious programs, we have antivirus applications, which have existed for quite a long time, such as Kaspersky Internet Security, as well as products from Microsoft Corporation, Symantec, McAfee, Trend Micro, F-Secure, and many others. These security applications use a wide variety of detection and treatment technologies, including signature and heuristic checks, virtual machines and emulators, etc. These technologies provide efficient detection and removal of various malicious applications and the consequences of their operation.
However, it should be noted that the development of malicious applications is always evolving, and the creators of malicious applications use cutting-edge methods to avoid or counter antivirus applications. One such technique involves methods for spreading malicious applications which can actively infect files (i.e., viruses) or can be spread on the network and by email (i.e., worms). Additionally, the spread of malicious applications can exploit various vulnerabilities in operating system software and user applications, as well as social networks, targeting in particular lay persons without much expertise in computer security. Many malicious applications can be quite difficult to detect and remove, even for experts.
Malicious applications can be installed whose sole function is to provide remote control of the infected computer (i.e., backdoor), conceal certain objects or activities in the operating system (i.e., rootkits), or avoid performing actions that are obviously malicious (for example, fake antivirus applications), all of which makes detection more difficult. Code obfuscation also substantially complicates the detection of malicious applications, many of which consist of not just one executable file but may be composed of multiple related components, each of them executing its own part of the malicious functionality.
For example, U.S. Pat. No. 7,540,030 proposes a system for removal of malicious applications from a computer. For this purpose, a special CHECK scenario is used on the infected computer, which performs a search for malicious applications and for consequences of their operation. In case if the CHECK scenario finds a malicious application, a FIX scenario is run thereafter, which cures the user's computer.
Removal of a malicious application does not guarantee that it will be removed from the computer forever. There are a number of composite malicious applications, which can restore a deleted component using the other components. For instance, U.S. Pat. No. 7,533,131 proposes a method for removal of malicious applications that try to restore copies of themselves. Various solutions, described in U.S. Pubs. No. 2007/143843 and 2006/0130141, are used to determine the effectiveness of the performed treatment by verifying the fact of removal of malicious applications. In addition, even if all components of malicious applications were removed, it is often impossible to completely reverse all consequences of the malicious applications' operation, i.e. created and/or modified files, or created and/or modified registry keys.
Another problem relates to problems that may be caused as side-effects of the removal processes themselves. For example, the treatment of a computer system may require removal of an operating system file that is infected but still necessary for the operating system to work properly; in this case, removal of such a file will not allow the operating system to work correctly or even to load in the first place. Therefore, a solution is needed that can effectively treat infected computer systems while avoiding the problems outlined above. | {
"pile_set_name": "USPTO Backgrounds"
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Users and developers of networked applications and systems desire reliable, faster and easier to use methods of communicating information between source and destination computer applications and operating environments. Traditional messaging techniques require each application to know the specific serialized format of a message, or require communication between the operating environments of the sender and receiver to provide information or meta-data so that the receiver can interpret the message. Computer users and applications developers are desirous of new methods and computer apparatus for communicating messages which decrease the amount of configuration and runtime overhead involved.
Most distributed computing applications today use synchronous communication technologies, such as remote procedure calls. Such synchronous communications require a sender of a request to wait for a response from the receiver of the request before it can proceed and perform other tasks. The time that the sender must wait depends on the time it takes for the receiver to process the request and return a response. Synchronous communication mechanisms also require the sender and the receiver to be operating simultaneously.
In contrast, using asynchronous communications, senders make requests to receivers and can move on to perform other tasks immediately. If a response is expected back from the receiver, it is up to the original sender to decide when it will actually look for and process the response. Most importantly, there is no guarantee that receivers will process requests within any particular period of time. In fact, with asynchronous communications, there are no requirements that receivers be running nor even the communications infrastructure be available in order for a sender to initiate a request.
Message queuing systems implement asynchronous communications by enabling applications to send messages to and receive messages from other applications. These applications may be running on the same machine or on separate machines connected by a network. When an application receives a request message, it processes the request by reading the contents of the message formatted in a known pattern and acting accordingly. If required, the receiving application can send a response message back to the original requester.
Many applications are now using message queuing networks for the enhanced communication delivery reliability between networked computer systems provided by sending messages asynchronously across a message queuing enterprise network. However, these messages are simply received as type-less buffers of raw data that are passed between applications. In some instances, these messages have additional signaling information attached that describe how the message should be sent by the underlying sub-system. However, the messages do not provide any semantic information that enables the message recipient to interpret the meaning of the message contents. To communicate, the source and destination applications rely either on private message content encoding schemes or prior arrangements between the applications to only send messages of a certain type. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to a liquid supply apparatus for supplying a liquid such as ink, and a liquid ejection apparatus for ejecting a liquid such as ink.
2. Description of the Related Art
Liquid ejection apparatuses include, for example, an inkjet printing apparatus that ejects ink as liquid from a print head as a liquid ejection head to print an image. In such a printing apparatus, the ink is supplied to the print head from an ink tank (liquid storage section) installed independently of the print head, and when the amount of ink remaining in the ink tank has become zero, the ink tank is replaced with a new one.
U.S. Pat. No. 5,179,389 discloses the structure of using a pressure sensor in contact with ink to detect pressure applied to the ink in such an ink tank for detection of the amount of ink remaining in the ink tank. | {
"pile_set_name": "USPTO Backgrounds"
} |
This invention relates generally to gas-fired condensing furnaces. More specifically, the present invention relates to a corrosion resistant condensing heat exchanger for use in the corrosive environment of a gas-fired condensing furnace and to the method of manufacture thereof.
Due to the cost and shortage of natural gs, attempts have been made to design and construct more efficient gas-fired hot air furnaces. One method for maximizing the heat energy transferred from a heating fluid, i.e. combustion gas, to air to be heated, i.e. the air in the enclosure or space to be heated, is to transer as much latent heat as possible from the water vapor in the heating fluid to the air to be heated. Thus, increases in furnace heating efficiency have been accomplished by cooling the heating fluid, while still within the furnace, to below the dew point to recover some of the latent heat of vaporization as usable energy. This is generally accomplished by adding a condensing heat exchanger to the primary heat exchanger, and passing air to be heated initially over the condensing heat exchanger, and then over the primary heat exchanger. Depending on the type of condensing furnace, efficiencies can be in the low-to-mid 90% range.
Some furnace heat exchangers have been constructed from two engineering metal sheets such that a fluid flow path is created when the two sheets are stamped and assembled. This type of heat exchanger is known as a clamshell heat exchanger. The corrosive environment of a condensing heat exchanger, which may have a variety of acids, including H.sub.2 SO.sub.4 or HCL, necessitates different material requirements that those typical of the primary heat exchanger. Concentrations of as little as 10 ppm (parts per million) of H.sub.2 SO.sub.4 or HCL may severely corrode bare steel and pit aluminum and copper. Accordingly, a condensing heat exchanger must be constructed of material having good heat transfer, adequate strength, minimum material thickness, resistance to chemical attack, and low manufacturing costs. Due to the material requirements for the corrosive environment of a condensing heat exchanger, these heat exchangers are generally manufactured from 300 Series stainless steel which is more costly than carbon steels or other engineering metals previously associated with furnace heat exchanger construction. Organic coatings on carbon steels, which are applied from a liquid or powder state, perform very poorly when used in condensing heat exchangers. Such coatings inherently contain voids thereby causing localized corrosion of the steel substrate. Sheet coatings of polymeric material laminated on solid sheets of metals are free of voids and withstand the fabricating process, but after furnace operation blisters are formed on the laminating surface. The blisters are formed by the coalescence of water molecules that permeate through the polymer film and become trapped at the film-steel substrate interface. These blisters could impede the passage of flue gas and increase the pressure drop across the heat exchanger, thus causing the furnace to operate improperly. | {
"pile_set_name": "USPTO Backgrounds"
} |
When using absorbent articles such as sanitary napkins, panty-liners, and incontinence guards for light incontinence, the absorbent article should be designed in such a way that the article is comfortable to wear and provides the best possible protection for items of clothing. When a user moves about, the briefs and the absorbent article change position, which can cause the absorbent article to slip into an incorrect position and/or crumple together, if the article is not correctly configured.
A great many techniques are known for solving the problem of getting the absorbent article to remain in position when the user moves. By way of example, reference may be made to U.S. Pat. No. 5,772,648, in which so-called wings are used together with an adhesive sheet bearing against the briefs. The aim is to secure the absorbent article on the briefs in order, in this way, to ensure that the absorbent article remains in position relative to the briefs. Each wing includes a tab of bendable material which is secured to a separate sheet.
The separate sheet is secured on the backsheet of the absorbent article via securing members along a longitudinal, centrally located securing line which extends the entire length of the separate sheet. The wings can be folded in between the backsheet and those parts of the separate sheet which are not secured to the backsheet. Upon use, the wings can be removed from the folded-up position and thereafter folded around the briefs in order thereby to lock the absorbent article to the briefs. The separate sheet has an adhesive sheet on that side of the separate sheet which, during use, faces towards the briefs, and, during use, the adhesive sheet adheres to the briefs and additionally locks the absorbent article to the briefs.
A problem with the absorbent article according to U.S. Pat. No. 5,772,648 is that the whole of the separate sheet is fixed along the backsheet of the absorbent article, which means that the space formed between the separate sheet and the backsheet includes shallow longitudinal pockets in which the wings can be tucked. To make room, the wings have to be folded in two several times to make room in the pockets. This gives rise to an undesired thickness on the backside of the article on both sides of the longitudinal securing lines of the separate sheet. In those cases where the absorbent article is used with the wings in the folded-up position, the absorbent article can be felt to be uncomfortable on account of the thickness. In addition, the thickened side portions can cause the thinner part of the absorbent article placed between the thickened side portions to collapse, on account of the differences in thickness, when the absorbent article is exposed to pressure from outside, i.e., during use. If the wings were to be made small enough to have room in the pockets without being folded, they would not be large enough to be able to be folded around the briefs in a satisfactory manner.
Another problem when the whole of the separate sheet is secured is the fact that the separate sheet can be considered to constitute a part of the backsheet since the separate sheet directly transfers movements to the backsheet via the longitudinal securing members. When the wings are folded around the briefs during use, and when the adhesive sheet bears against the briefs, the separate sheet and also the absorbent article are held in place against the briefs, which means that movements from the briefs are transmitted directly to the absorbent article. The movements of the briefs often differ from the movement of the lower abdomen when the user moves, for which reason a direct transfer from briefs to absorbent article can give rise to the absorbent article moving with the briefs out of position from the intended position against the user's lower abdomen. If the briefs move out of position, this reduces the ability of the article to absorb the body fluids it is intended to absorb, for which reason the protective effect the absorbent article is intended to provide is not obtained to a satisfactory extent.
There is therefore a need for an absorbent article which has an improved capacity to keep the absorbent article in position relative to the user and which at the same time is comfortable, reliable and easy to use. | {
"pile_set_name": "USPTO Backgrounds"
} |
Ophthalmic formulations often comprise compounds that provide desirable properties to the formulation. When these formulations are instilled in the eye, the properties of such compounds can help prevent ophthalmic problems such as bioadhesion and the formation of friction-induced tissue damage, as well as encourage the natural healing and restoration of previously damaged tissues.
Formulations are typically developed with a target viscosity to ensure that they are comfortable for the user and do not cause undesirable side effects such as blurring. A suitable formulation viscosity can help ensure that an ophthalmic formulation used in dry eye disorders will relieve dry eye-associated symptoms and/or treat the underlying disorder. In drug delivery applications the viscosity of ophthalmic formulations may be chosen to ensure that a pharmaceutical agent carried in the formulation remains in the eye for a desired length of time. Given its criticality, the viscosity of ophthalmic formulations should remain as stable as possible over time.
The viscosity of formulations can be affected by storage conditions (e.g., environmental temperature, time of storage, ambient light, etc.). Also, ophthalmic formulations must be sterilized before use, and the sterilization process, particularly heat sterilization, can dramatically affect the viscosity of such formulations.
Ophthalmic formulations have been previously described that utilize galactomannan-borate systems. U.S. Pat. No. 6,403,609 to Asgharian, entitled “Ophthalmic compositions containing galactomannan polymers and borate,” describes such systems and is herein incorporated by reference in its entirety. The cross-linking of galactomannan and borate is responsible for the gel-forming behavior of the described formulations. Magnesium has been utilized in guar formulations to assist in the hydration of guar. See Vega-Cantu et al., “Effect of Magnesium and Iron on the Hydration and Hydrolysis of Guar Gum” Biomacromolecules, Vol. 7:441-445, 2006. | {
"pile_set_name": "USPTO Backgrounds"
} |
This invention relates generally to balanced moving armature magnetic transducers, and particularly to means for protecting the moving armature from damage affecting the operating characteristics of a transducer caused by mechanical shock.
In contemporary balanced moving armature magnetic transducers, the element or elements comprising the armature usually function as its own restoring spring, providing mechanical stability and approximate magnetic balance of the armature in its quiescent state. Usually a portion of the armature is surrounded by an electrical signal coil, and functions to convey magnetic signal flux through the coil. Consequently the armature is required to have high magnetic permeability and low coercive force, in addition to providing a restoring spring function.
When materials for armatures are heat treated to develop their magnetic properties, they generally have limited mechanical yield strength. This limits the strength of the armature in its restoring spring function. The resistance to mechanical shock of a magnetic transducer having an armature of such materials is undesirably limited. In particular, a shock from an external source may easily and irreversibly alter the position of the armature by plastic damage, thus destroying its magnetic balance.
The foregoing problem is encountered by the hearing aid or hearing instrument art, in which the sound output generating devices (called receivers) are commonly fabricated using balanced moving armature magnetic transducer technology. In fact, susceptibility to mechanical shock is presently considered the second most likely cause of failure in the field, and failure of the receiver causes failure of the entire hearing aid.
Past efforts have attempted to increase the shock resistance of these transducers by the use of snubbing structures that limit the extent of movement or excursion of the vibratory part of the armature when subjected to shock. For example, U.S. Pat. No. 4,272,654 to Carlson discloses plural discrete ridges or continuous ridges formed of coil encapsulant as snubbing means for the inner arm of a folded armature of the general type disclosed in U.S. Pat. No. 3,515,818 to one of the present applicants. U.S. Pat. Nos. 5,647,013 to Salvage et al and 5,757,947 to Van Halteren et al disclose snubbing means for an armature of the general type disclosed in U.S. Pat. No. 3,617,653 to Tibbetts et al. U.S. Pat. No. 5,647,013 discloses several forms of snubbing means including formations pressed in and away from the plane of the armature body, or blobs of adhesive or other settable material applied to the armature, or a spacer having a restricted opening situated between the coil and the permanent magnet structure, or means for altering the shape of the coil tunnel. U.S. Pat. No. 5,757,947 discloses snubbing means forming a part of the drive pin structure connecting the transducer with a diaphragm, or alternatively a U-shaped element disposed on the side of the magnet elements facing away from the coil. These various snubbing means are provided at designated locations of the armature, but in all cases the direction of snubbing is parallel with the drive pin, i.e., directed to limit the excursion of the armature in the direction of the permanent magnetic flux. In general, this direction is normal to a major plane of the armature.
Analysis of mechanical shocks has found the effects to be complex and dependent on the vector direction of the shock. Instrinsically, a shock of external origin may have any arbitrary direction, as exemplified by a hearing aid inadvertently dropped to the floor. The present applicants have found that the full effect of a given shock upon the subsequent operating properties, and also the subsequent resistance to other shocks, is considerably dependent on the direction of the original shock as well as its magnitude. They have further found that snubbing of the armature in the direction of the drive pin, which may be provided intrinsically by the magnets or pole pieces or by means such as those described in the above-mentioned patents, only partially protects the armature from damage. This is particularly the case for folded armatures of the general type described in U.S. Pat. No. 3,515,818.
It has been discovered that when a basic folded armature transducer of the general type disclosed in U.S. Pat. No. 3,515,818 is shocked in the edgewise direction, i.e. the direction normal to that of the flux field and normal to the direction of extent of its vibratory portion, with or without parallel protective snubbing as described above, significant plastic damage to the armature readily occurred, although in this particular case there appeared to be little shift in the magnetic balance of the transducer. However, the damage to the armature significantly compromised the resistance of the transducer to a shift of magnetic balance under a subsequent shock in a different vector direction. This led to the conclusion that the armature should be snubbed in this edgewise direction of shock, hereinafter referred to as edgewise snubbing.
Analysis was then given to a determination of the degree of edgewise snubbing that would be sufficient to protect the armature not only for edgewise shocks in the direction normal to the magnetic flux and to the direction of extent of the vibratory portion of the armature but also for shocks in other possible vector directions. Analysis determined that for a shock of given magnitude in the edgewise direction, a corresponding edgewise snubbing clearance (the space between the relevant edges of the armature and the snubbing means) could be determined such that the armature would survive elastically. However, it was further found that such degree of edgewise snubbing was not sufficient to protect the armature, and to avoid shift of magnetic balance, under shocks of the same magnitude but in other equally possible vector directions. In fact, it was determined that the edgewise snubbing clearance was required to be reduced by a large factor, for example on the order of three, to provide sufficient practical protection.
Based on the foregoing observations, the features of the present invention include the provision of specific snubber means having a surface or surfaces oriented to limit the edgewise excursions of the armature, i.e. normal to the direction of the permanent magnetic flux and to the direction of extent of the vibratory portion of the armature.
Various means may be provided for this edgewise snubbing, including means limiting the excursions of the armature in the direction normal to both the direction of the magnetic flux and the direction of extent of the vibratory portion of the armature.
The edgewise snubbing means of the invention may take any of several forms including filler pieces or a member having opposed surfaces between which the armature is extended, in either case to provide a desired edgewise snubbing clearance. | {
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1. Field of the Invention
The present invention relates to quick-release device, and more particularly to a quick-release device of a bicycle brake cable, which is mounted relative to a brake lever.
2. Description of Related Art
A brake device of a bicycle must be designed under two factors including brake effect and quickly releasing the tension of the brake cable when changing the wheel. A conventional brake device of a bicycle includes an L-shaped guider mounted to a free end of a brake arm and two brake pads for clamping the wheel rim to achieve the effect of brake. However, the two brake pads are very closed to the wheel rim and the tire has a diameter greater than a width of the wheel rim. Consequently, the tension of the brake cable must be greatly released to enlarge the width between the two brake pads before changing the wheel. As a result, the tension of the brake cable must be adjusted again after changing the wheel. It will take a lot of time when changing the wheel.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional brake device of a bicycle. | {
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A device for erecting walls and/or ceilings especially for exhibition purposes as at fairs and to be used as exhibition pavilions, free-standing structures, single- or multi- story lobby booths and the like, comprises a support-shaped section, a beam for wall and/or ceiling segments being detachably affixed to approximately cross-sectionally T-shaped webs of the support shape-section and a clamp detachably affixed to the inside of the beam which is hollow. The clamp in the assembly position is associated with the undercut channels defined by the webs of the support shaped-section and tightened by a rotationally driven tightening system against two adjacent webs of the support shaped-section while the clamp is simultaneously affixed inside the beam by the tightening system.
In such devices, short, support shaped-sections as a rule are the central or the corner erection components and determine the angles subtended between the walls or ceilings.
The walls or ceilings are held by beams in the form of hollow shaped-sections engaging the support shaped-section by clamping locks. As a rule the various wall and/or ceiling erections, for instance fair booths, which are to be set up in simple manner, will be regular quadrangular, hexagonal or octagonal constructions.
The German Offenlegungsschrift 37 03 907 discloses a device of the initially cited kind and its object already is a further development of a similar device disclosed in the German patent 29 31 026.
The known clamping-lock design of German patent 29 31 026 does incur a drawback in that two to three revolutions of the tightening system, which is a screw, are required to actuate such a clamping lock. As a result assembly and disassembly times of the wall and ceiling constructions are significantly lengthened. In the case of inexpert (i.e., excessive) actuation of the clamping lock, there is the further danger that the walls of the beam, which as a rule is made of aluminum, shall be unduly stressed by expanded rear ends of the lateral retaining elements, and externally visible pressure spots arise at the support walls.
The German patent 29 31 026 incurs further drawbacks in that on account of the loose central retaining element, accurate positioning of the hollow shaped-section (beam) is substantially hampered, in that the two lateral retaining elements will close on one side so that there take place shifts of the clamping lock and the hollow shaped-section it holds, and in that it is impossible to accurately center the clamping lock inside the hollow shaped-section because this clamping lock is merely held in place by the screw head of the tightening system. Because the two lateral retaining elements of the known clamping lock do not rest automatically, disassembly of the hollow shaped-section from the support shaped-section is made more difficult.
While some of the above shortcomings could be averted by the known clamping lock of the German Offenlegungsschrift 37 03 907, on the other hand the cost involved to do so was prohibitive because of a special design of the clamping lock. Illustratively this known tightening system designed as a cam comprises a metal core clad in an injection-molded plastic. An actuation groove is present in the plastic coating and externally covers each lateral retaining element. The metal core of the known tightening system consists of two integral cylindrical elements however eccentrically offset from each other, one of which constitutes the actuation head in the form of a hexagonal socket and projects from the plastic cladding, the other forming an inner support for the plastic cladding used to hold the tightening system inside the central retaining element and to actuate the lateral retaining elements. Furthermore, the second cylindrical element comprises integral, bilaterally supporting collars extending on both sides of the actuation groove.
The drawback in the German Offenlegungsschrift 37 03 907 that hampers practical application is that on one hand the plastic cladding of the tightening system cannot indefinitely withstand the high forces generated when handling said device and therefore the clamping lock will be unfit for service after short operation because of the wear of the tightening system. The tightening system cannot be made entirely of metal because it is too complex in shape. Again the metal core of the known plastic-clad tightening system can be manufactured only at high cost because of its complex shape.
It should be noted that the term "shaped-section" is used for convenience, and includes all sorts of cross-sections, such as U-sections, T-bars, and the like. | {
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The present application claims priority under 35 U.S.C. xc2xa7119 to Japanese Application No. 2000-117991 filed on Apr. 19, 2000, which is hereby incorporated by reference in its entirely for all purposes.
1. Field of the Invention
The present invention relates to a semiconductor device and method of manufacture, and particularly, the present invention relates to a semiconductor device having memory cells and peripheral circuits which control the memory cells, and to a method of manufacturing such a semiconductor device.
2. Description of the Related Art
Semiconductor devices have been rapidly developing in which memory cells and peripheral circuits controlling the memory cells are formed in the same semiconductor substrate. Particularly, significant developments have been made in the area of systematic semiconductor devices which include a function of a semiconductor memory circuit, such as a dynamic random access memory (DRAM) and a function of a logic circuit.
Metal oxide semiconductor (MOS) transistors of such logic circuit have been employed to improve the driving ability of an electric current. Silicide layers are formed on gate electrodes, source regions and drain regions of the MOS transistors using a Self-Aligned Silicide (Salicide) method. Thereby, a resistance of the gate electrode and the source and drain regions is reduced and the logic circuit is capable of a high speed operation is.
Also, MOS transistors of the memory cells, particularly of the DRAM, must be capable of required to realize a high speed operation in order to transfer large amounts of data, such as image data. To realize such a high speed operation, it has been proposed to form silicide layers on the gate electrodes, source regions and drain regions of MOS transistors in the memory cells.
However, in the MOS transistor of the memory cells of the DRAM, concentrations of impurities in the source regions and the drain regions are set to low levels to restrain a short channel effect, to slacken a concentration of an electrical field in the drain region and to maintain a retention time. Therefore, junctions between the source regions or the drain regions and the semiconductor substrate are formed in the vicinity of a surface of the semiconductor substrate.
Consequently, if the silicide layers are formed on the gate electrodes, source regions and the drain regions of the MOS transistors in the memory cells of the DRAM, a high speed operation could be realized, but leak current from the source and drain regions to the semiconductor substrate would increase.
The silicide layers of the MOS transistors of the memory cells are simultaneously formed in the same step of forming the silicide layers of the MOS transistors of the peripheral circuits. Here, a method of forming an insulating layer, such as a nitride layer on the MOS transistors of the memory cells can be considered so as to avoid formation of the silicide layer on the MOS transistors of the memory cells. So, as it is impossible to form the silicide layers on the gate electrodes of the MOS transistors of the memory cells, an access time of the memory cells may be increased. Therefore, it is difficult to realize a high speed operation of the DRAM.
An object of the present invention is to provide a semiconductor device including peripheral circuits and memory cells which are capable of realizing a high speed operation while securing a predetermined data-retention-time.
To achieve the object, in a semiconductor device having memory cells and peripheral circuits which control the memory cells, wherein the memory cells and the peripheral circuits are formed on a semiconductor substrate, source regions, drain regions and gate electrodes of MOS transistors in the peripheral circuits are comprised of a refractory metallic silicide layer. Gate electrodes of MOS transistors in the memory cells are comprised of the refractory metallic silicide and source and drain regions of the MOS transistors in the memory cells are not comprised of the refractory metallic silicide layer.
According to the present invention, a semiconductor device can be realized which includes peripheral circuits and memory cells which are capable of a high speed operation while securing a predetermined data-retention-time. | {
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The present invention concerns a transfer case or differential with a bevel-pinion shaft which is supported in a drive housing by two spaced and axially pretensioned angular-contact ball bearings and which drives via a bevel pinion and ring gear a differential unit mounted in the drive housing, axle shafts being supported in the differential unit which are operationally connected with each other via output and differential gears.
Such differential gear boxes permit the drive wheels of each axle shaft to roll in slip-free fashion at a different speed of rotation in travelling over a curved path. A bevel-pinion shaft or a drive shaft with a bevel gear drives a ring gear rotationally joined with the differential unit in the interior of which are mounted output and differential gears. While driving straight ahead, these differential gears in the differential unit are at rest so that both axle shafts turn at the same speed of rotation as the ring gear. Upon driving in a curved path, a difference occurs in the speed of rotation of the two axle shafts. In this case, the differential gears rotate and result in the fact that the increase in the speed of rotation of the one axle shaft compared to the speed of rotation of the ring gear is precisely as large as the decrease in the speed of rotation of the other axle shaft compared to the ring gear.
Such a generic differential gear box is described, for example, in the handbook xe2x80x9cRoller Bearingsxe2x80x94Computation and Designxe2x80x9d by W. Hampp, Springer-Verlag Berlin/Heidelberg/New York in Figure 88. The bevel pinion shaft is supported in this case via two spaced conical-roller bearings pretensioned in the axial direction. The pretensioning occurs as a result of the conical-roller bearings being moved toward each other in the axial direction via a threaded connection.
Disadvantageous here is that fact that due to the pretensioning of the conical-roller bearings, sliding friction develops between the end walls of the conical rollers and the edge surface of the bearing rings, which leads to wear of the conical rollers and edge surfaces. This wear, in turn, is responsible for loss in pretensioning of the bearing, as a result of which there occurs an increase in tooth play between the bevel pinion and the ring gear, with its negative consequences.
In connection with this, a differential gear box is known from U.S. Pat. No. 3,792,625, whose bevel-pinion shaft is supported by two spaced apart angular contact ball bearings. Such a bearing arrangement however does not meet the requirements for high performance drives and was therefore not useable from a technical standpoint. For one, the carrier teeth and also the rigidity are too small. Therefore it results in an uneven carrier stopping that lowers the service life of the drive and generates noise when the teeth of the bevel-pinion shaft and the ring gear mesh.
The present invention is therefore directed to developing an improved bearing arrangement for the bevel-pinion shaft of a differential.
According to the present invention, this problem is solved through the fact that the angular contact ball bearings are designed as unilaterally loadable double-row tandem angular-contact ball bearings, which each include a one piece inner bearing race and a one piece over bearing race and which face each other in an O-arrangement.
The advantages of the solution of the present invention compared to the classical solution with conical-roller bearings are the following:
Due to the substantially reduced frictional moment based on the lack of sliding friction in the bearing arrangement of the present invention, there necessarily also result reduced bearing temperatures and accordingly also a reduced oil-sump temperature. Thus, overall, better efficiency and a lower power loss of the bearing arrangement are attained. Upon installation of the bearing arrangement of the present invention in a motor vehicle, reduced fuel consumption is now possible as a result of the lower power loss. The approximately 40xc2x0 C. lower temperatures of the oil sump also make it possible that a lighter housing material, for example, a magnesium alloy can be employed for the differential housing which, in turn, makes itself felt in a saving of weight.
A further advantage is a reduced wear of the bearing, which amounts to only about {fraction (1/10)} of the wear for the classical solution. This reduced wear accounts for the avoidance of axial shifting of the bevel-pinion shaft along with the known negative increase in tooth play between the bevel pinion on the bevel-pinion shaft and the ring gear connected with the differential unit.
Further advantageous refinements of the solution of the present invention include that the races of a bearing exhibit respectively the same or a different diameter and the same or a different pressure angle.
According to a further feature, the bearing balls of both races of a bearing are guided in cages and have the same or a different diameter.
Preferably, the first double-row tandem angular-contact ball bearing positioned next to the bevel pinion on the bevel-pinion shaft is larger than the accompanying second bearing. This appropriate refinement is undertaken because the greatest loads both in the radial as well as in the axial direction need to be accommodated in the immediate vicinity of the bevel pinion.
Finally, it is preferred that the inner ring of the second double-row tandem angular-contact ball bearing is supported in the axial direction against a deformable sleeve. After adjustment for the desired pretensioning, this sleeve provides for the fact that the adjustment screw is likewise put under pretensioning through the action of a counter force. Spontaneous loosening of this threaded screw is therefore not possible.
The present invention is described in more detail on the basis of the following preferred embodiment. | {
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1. Field of the Invention
The invention is related to the field of magnetic disk drive systems and, in particular, to a seed layer for a heat spreader in a magnetic recording head. More particularly, a heat spreader layer grown on the seed layer has a well-oriented crystalline structure to improve the thermal conductivity of the heat spreader layer and to improve heat dissipating characteristics in the magnetic recording head.
2. Statement of the Problem
Many computer systems use magnetic disk drives for mass storage of information. Magnetic disk drives typically include one or more magnetic recording heads (sometimes referred to as sliders) that include read elements and write elements. A suspension arm holds the recording head above a magnetic disk. When the magnetic disk rotates, an air flow generated by the rotation of the magnetic disk causes the air bearing surface (ABS) side of the recording head to fly at a particular height above the magnetic disk. The height depends on the shape of the ABS. As the recording head rides on the air bearing, an actuator moves an arm that is connected to the suspension arm to position the read element and the write element over selected tracks of the magnetic disk.
To read data from the magnetic disk, transitions on a track of the magnetic disk create magnetic fields. As the read element passes over the transitions, the magnetic fields of the transitions modulate the resistance of the read element. The change in resistance of the read element is detected by passing a sense current through the read element and then measuring the change in voltage across the read element. The resulting signal is used to recover the data encoded on the track of the magnetic disk.
In one scheme used to write data to the magnetic disk, the write element passes a magnetic flux through a first write pole and into the magnetic disk. The magnetic flux flows through a soft underlayer in the magnetic disk and returns to the write element through a second write pole. The magnetic flux creates a transition in the magnetic disk that is stored as a bit.
A typical magnetic recording head is fabricated on a substrate using the following layers. An undercoat, such as Al2O3, is first formed on the substrate. Typical substrates are made from an Alumina-Titanium Carbide composite (AlTiC) material. The layers for the read element are then formed on the undercoat, where the layers of the read element typically include a first shield layer, a first gap layer, the read element (e.g., a magnetoresistive (MR) read element), a second gap layer, and a second shield layer. The layers for the write element are then formed. The layers for the write element typically include a first write pole, a coil, a second write pole, and gap material or insulating material between the write poles. The layers of the write element are then covered with an overcoat, such as Al2O3. A structure such as this for a magnetic recording head is illustrated in FIG. 1.
In normal operation of a magnetic disk drive system, heat can affect the magnetic recording head. For instance, because the magnetic recording head is fabricated from different materials having different coefficients of thermal expansion, the pole tips of the write element may protrude toward or recess away from the magnetic disk, which can negatively affect the operation of the write element. To alleviate the effects of heat, magnetic recording heads may be fabricated with a heat spreader. The heat spreader (or heat spreader layer) may be formed in the undercoat between the substrate and the first shield using a metallic material having a high thermal conductivity. Some typical materials used for a heat spreader layer are Tungsten (W) or a NiFe alloy. The heat spreader helps to dissipate heat in the magnetic recording head.
One problem with using Tungsten (W) for a heat spreader is that it corrodes when it is exposed at the ABS of the magnetic recording head. Thus, a heat spreader formed from Tungsten (W) has to be patterned, which requires extra lithography, hard mask, and etching steps. Also, the areas where the heat spreader is removed needs to be filled with an insulating material which adds time and expense to the fabrication process.
Another material suggested to be used as a possible heat spreader is Aluminum Nitride (AlN). Aluminum Nitride as a material has high thermal conductivity much like W, but does not corrode as easily. Unfortunately, when Aluminum Nitride is grown on an AlTiC substrate or an amorphous Al2O3 undercoat, the thermal conductivity is reduced which makes Aluminum Nitride less effective as a heat spreader. As a result, Aluminum Nitride has not been effectively used in magnetic recording heads as a material for a heat spreader. | {
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The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A cloud-based service of a customer is typically deployed in a cloud computing environment using the following workflow. First, a tenant model is generated based on user inputs provided by the customer. Subsequently, based on the tenant model, cloud resources such as computing, networking, and storage resources are located in the cloud computing environment and are committed/allocated to the service according to the customer's requests. Thereafter, the service is activated (i.e., started or executed) using the allocated resources.
In this process, if the service deployment fails due to unavailability of one of the resources, all other committed resources have to be rolled back (unallocated and released). Thereafter, the whole deployment process has to be reinitiated to reattempt all resource allocations in the intended sequence. This adversely affects deployment performance and customer experience. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to a system and a method for dynamically adjusting the position of wheels of an automotive vehicle. More particularly, the present invention relates to a system and a method for dynamically adjusting the toe angle of wheels of an automotive vehicle in response to the driving conditions of the wheels and the vehicle speed.
2. Description of the Art
When an automotive vehicle is turning either by travel along a curved road or during cornering, driving safety would be enhanced if the rear wheels could be moved in or out of phase with the direction of the steering front wheels. It is known, for example, that when a vehicle turns while at low speed, the diameter of the path taken by the rear wheels is minimized if the rear wheels are adjusted to a directional orientation opposite those taken by the steering front wheels. Additionally, at high speed, better traction is achieved during turns if the rear wheels are adjusted to assume the same directional orientation as the front wheels.
The directional orientation of the wheels of automotive vehicles, other than by steering, is conventionally determined by the toe angle. The toe angle is normally controlled by the running speed of the automotive vehicle and the preset toe-in. Other operating conditions of the vehicle conventionally have no effect on the toe angle of the wheels. Thus, the wheels of an automotive vehicle do not assume optimum positions for various driving conditions, such as turning or driving the surface of the road is wet or is iced over.
The present invention provides a system for adjusting the position of automotive vehicle wheels and a method for controlling the position of the automotive vehicle wheels that can ensure safe driving by adjusting the front and rear wheel positions in dynamic response to the running speed and operating conditions of the automotive vehicle. Additional advantages of the invention are set forth in part in the description which follows, and in part will be obvious from the description, or may learned by practice of the invention. | {
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Conventionally, there have been known many developer supply apparatuses capable of supplying a developer (dry developer or dry toner) to a predetermined object (a photoconductor drum or the like) to which the developer is to be supplied (hereinafter such an object will be referred to as a “target object”) in an image forming apparatus, and many developer electric-field transport apparatuses which are provided in the developer supply apparatuses (see, for example, Japanese Patent Publication (kokoku) No. H5-31146 and Japanese Patent Application Laid-Open (kokai) Nos. 2002-91159, 2003-98826, 2004-333845, and 2005-275127).
Such a developer electric-field transport apparatus is configured to transport a developer in a predetermined developer transport direction by use of a traveling wave electric field. Typically, in the developer electric-field transport apparatus, a large number of elongated electrodes are arrayed on an insulative base material. These electrodes are arranged along the developer transport direction. The developer is stored in a predetermined casing.
In the developer electric-field transport apparatus having the above-described structure, polyphase AC voltages are sequentially applied to the electrodes, whereby a traveling wave electric field is formed. By the action of the traveling wave electric field, the developer in a charged state is transported in the developer transport direction. | {
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1. Technical Field
The present invention relates in general to a system and method of providing smart graphical components. In particular, the present invention provides components that automatically determine the appearance and behavior characteristics.
2. Description of the Related Art
Today's computing environment is dominated by graphical user interfaces (GUIs). GUIs contain various graphical components, or widgets, that perform an array of different functions. For example, an icon is a common graphical component that usually consists of an image and some descriptive text. When an icon is activated (clicked, invoked, selected, etc.) it will typically launch an application or another graphical component that provides information or exposes some set of functionality to the user.
The facilities that are needed to create GUIs are provided by the operating system. Such facilities usually include a method to draw to the screen, process events (e.g., mouse clicks, keyboard press events, etc.), and a base set of widgets. Modern operating systems provide these functions to application developers who use them to create graphical applications, such as Lotus Notes. Furthermore, the operating system itself often uses these facilities to provide a desktop environment to the user. The Microsoft Windows™ and UNIX™ operating systems have included graphical facilities and a desktop environment since the 1980s.
Often times it is desireable to be able to place graphical components of the same type (e.g., icons) into different containers that appear on the display, such as toolbars, folders, and the like. Furthermore, it may be desirable for the component to vary it's appearance and behavior based upon the type of container in which it is located. For example, a toolbar is typically a small container usually nested inside of a larger container, such as a frame or a desktop. The size of the container, such as a toolbar, imposes size constraints on the graphical components that are included in the container. For example, when an icon is displayed inside of a desktop it may display both an image and descriptive text. However, if the same icon is placed in a different container, such as a toolbar, the developer may not wish to display the descriptive text in order to conserve space. Other behavior may also be different, such as whether a border is drawn around the graphical component when the user positions the mouse pointer over the object.
A challenge with graphical component placement is that such placement is often configurable by the user and, therefore, not known by the developer beforehand. Traditional systems address this challenge by providing similar, but different, graphical components that are added to the different containers. Likewise, behavior of the components in traditional systems is handled by the creation of similar, yet different, components.
For example, in traditional systems a toolbar-icon is created for placement in a toolbar while a desktop-icon is created for placement in a desktop. Developers using traditional systems and methods are challenged by the difficulty of moving graphical components from one type of container to another because of the different behavior and appearance attributes corresponding to the containers. What is needed, therefore, is a system and method that provides “smart” graphical components that detect their parent container type at runtime and adjust their behavior and appearance accordingly. What is further needed is a way to provide “smart” graphical components programmatically with code included with the component or through the use of a configuration file that is read and processed by the graphical component. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to an information processing apparatus for transmitting print data, a storage medium, and a control method.
2. Description of the Related Art
As a method of selecting an image forming apparatus when printing is performed, there is a method of performing a device search on a network using a multicast packet of the Service Location Protocol (SLP) or the multicast Domain Name System (mDNS), and selecting an image forming apparatus as a print destination from a device list of found devices.
On the other hand, as a method of selecting a device, there is also a method of selecting a device using near field communication (NFC). NFC is an international standard for passing a device over another device to perform near field communication. Devices having NFC functions are merely brought close to and held over each other to exchange various types of data.
Japanese Patent Application Laid-Open No. 2013-037687 discusses a method of employing an apparatus termed a printing pad to achieve printing using NFC, thereby enabling printing even if a printer and a mobile device are not organized on the same subnet network.
Japanese Patent Application Laid-Open No. 2013-037687, however, does not take into account the control in the case where it is possible to both select a printer using NFC and select a printer based on a device search on a network.
It is more convenient for a user if it is possible to select an image forming apparatus both using near field communication and based on a device search on a network. If, however, there are two methods of selecting an image forming apparatus, the user may be confused in determining the methods which should be used to select an image forming apparatus. | {
"pile_set_name": "USPTO Backgrounds"
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High velocity spraying processes based on combustion of oxygen-fuel mixtures (HVOF) or air-fuel mixtures (HVAF) allow coatings to be sprayed from variety of materials. HVOF and HVAF processes may generally produce sonic and supersonic gas jets including combustion products of the oxygen-fuel or air-fuel mixtures. High quality coatings can be sprayed at a high level of efficiency when the temperature of the combustion products is high enough to soften or melt the particles being sprayed and the velocity of the stream of combustion products is high enough to provide the required density and other coating properties. Different materials require different optimum temperatures of the sprayed particles in order to provide an efficient formation of high quality coatings. Higher melting point materials, such as cobalt and/or nickel based alloys, carbides and composite materials, may often require relatively high temperatures in order to soften the particles to a level sufficient to efficiently form high quality coatings.
Some of the parameters affecting the available range of temperatures and velocities available from the combustion products are combustion pressure, types of fuel and oxidizer and ratio of fuel/oxidizer flow rates. Commonly used fuels may include gaseous and liquid hydrocarbon fuels like propane, propylene, MAPP gas, kerosene. Hydrogen may also be used as a fuel. Liquid fuels may provide some advantages over gaseous fuels. The use of liquid fuels may be less expensive than gaseous fuels and may be more easily fed into combustion apparatus at high pressure by using pumps or pressurized tanks. Some of gaseous fuels, for example, propane, are supplied in tanks at relatively low pressure. A tank of a gaseous fuel at low pressure may require pre-heating in order to provide a spraying gun with high pressure gaseous fuel. The pre-heating isn't attractive from safety standpoint.
Combustion devices and other parts of combustion apparatus may require cooling because of high temperatures of combustion. Cooling, however, may result in heat losses from the combustion apparatus to the cooling media. This heat loss may be a factor that can affect the efficiency of the process, for example by influencing the temperature and velocity of a combustion jet. Heat losses may depend, at least in part, on the intensity of the cooling and the surface areas of the combustion apparatus that are being cooled by a cooling media.
According to some designs, compressed air or oxygen is fed through air passages surrounding the combustion chamber and the barrel/nozzle assembly in order to cool these parts. The compressed air is then fed from the passages into the combustion chamber and is used as an air supply for the combustion process. This “regenerative” heat exchange may be economical and may reduce heat losses from the combustion. Oxygen has a relatively low cooling efficiency, however, and cooling using only oxygen may not be sufficient to prevent an HVOF system, which may generally operate at a higher temperature than an HVAF system, from overheating.
Oxygen/fuel mixtures may achieve high combustion temperatures, in some cases reaching temperatures of 3000 degrees C. or higher. To protect the apparatus from damage due to these extreme temperatures, water is commonly used as a cooling media for oxygen/fuel mixtures. In addition to the use of water cooling systems, combustion chambers for burning oxygen/fuel mixtures, as well as other components that will be exposed to high temperatures, are often manufactured from copper or copper alloys. Very efficient cooling may be achieved using water as a cooling medium in combination with copper or copper alloy components. Unfortunately, such efficient cooling may result in relatively large heat losses, especially in combustion systems having large internal surface areas and/or numerous turns in the path of combustion products. | {
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Computer-supported co-operative work (CSCW) is a field of study that addresses how collaborative activities and their coordination can be supported by means of computer systems. The embodiments of CSCW provide for people working in groups using the enabling technologies of computer networking, associated hardware, software, services, and techniques that are often referred to as groupware, computer-assisted collaboration or media-assisted collaboration.
A collaboration session typically involves multiple participants who access the session via any of a plurality of well-know communication medium such as, for example, terrestrial telephony (e.g. Public Switched Telephony Network (PSTN)), mobile (a.k.a. cellular) telephony (e.g. Global System for Mobile Communications (GSM)), broadband connection (e.g. Internet Protocol (IP)), and other radio-based connections (e.g. Wi-Fi (a.k.a. IEEE 802.11)). Some collaboration systems support the use of different communication media by each of the participants.
Each participant uses a computing-platform based device (i.e. access appliance) such as, for example, a personal computer, a personal digital assistant (PDA), a mobile phone, an Internet browser running on any of the these devices, and other similar communication devices. Many currently available collaboration systems either support a limited selection devices or require that a collaboration system client application (e.g. Internet browser plug-ins) be loaded and executed on the device in order to participate in a session. Due to various security, performance and convenience considerations, many participants would prefer to be able to use a platform of their choice without the need to load a collaboration system specific client application.
The collaboration session is hosted by a computing-platform based system often referred to as a collaboration server. The collaboration server can be either a monolithic system or a distributed system including components shared with other systems. The capabilities of the collaboration server determines what types of media can be included in the collaboration session. Media types can, for example, include audio, video and data. Data media can include files, web pages, bit-streams and other similar data representations in a variety of well know encoding formats. The capabilities supported in the collaboration session can be further determined by parameters managed by an administrator of the collaboration system.
Each collaboration session typically has a designated organizer who arranges for the session to be established and who may specify parameters for the session.
Typically, each participant in the collaboration session is authenticated before joining the session. When a participant joins, or leaves, the session the event is made known to other participants. The arrival and departure of a participant is announced using an identity assigned to the participant. Authentication and the identities of participants are typically managed by an administrator of the collaboration server, the organizer of the collaboration session, or a combination of the two. In some collaboration contexts it is desirable that the participant be able to control the identity use to identify him/her and to announce his/her arrival and departure (e.g. when the participant wishes to remain anonymous or wishes to monitor the collaboration session without the other participants being aware of his/her participation). This capability is not provided by currently available collaboration systems.
Typically collaboration systems are designed to permit each participant to join a collaboration session using any one platform via any one communications medium. With a growing diversity of platforms available and with the every growing pervasiveness of a multitude of communication media, participants want to be able to switch platforms and/or communication media while continuing to participate in a collaboration session. The ability to switch platforms and/or communication media would enable a degree of flexibility and mobility not afforded to participants by currently available collaboration systems.
Available collaboration systems that demonstration some of the shortcomings described above include WebEX™ (www.webex.com), GoToMeeting® (www.gotomeeting.com), and MicroSoft Office SharePoint Serve.
What is needed is a system and method for collaboration that permits participants to control their identity in a collaboration session, permits participants to change the access appliance used to access a collaboration session during the course of the session. | {
"pile_set_name": "USPTO Backgrounds"
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The present invention relates to a new and distinct cultivar of Solidago plant, botanically known as Solidago hybrida, and hereinafter referred to by the name ‘KLESH06001’.
The new Solidago is a product of a planned breeding program conducted by the Inventor in Stuttgart, Germany. The objective of the program is to create and develop new fast-growing Solidago cultivars with freely branching habit, flowering habit and attractive inflorescence coloration.
The new Solidago originated from a cross-pollination made by the Inventor in October, 2001 of a proprietary selection of Solidago hybrida identified as code number J 6, not patented, as the female, or seed, parent with a proprietary selection of Solidago hybrida identified as code number J 10, not patented, as the male, or pollen, parent. The new Solidago was discovered and selected by the Inventor as a single flowering plant within the progeny of the stated cross-pollination in a controlled environment in Stuttgart, Germany in August, 2002.
Asexual reproduction of the new Solidago by terminal cuttings in a controlled environment in Stuttgart, Germany since March, 2003, has shown that the unique features of this new Solidago are stable and reproduced true to type in successive generations. | {
"pile_set_name": "USPTO Backgrounds"
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Generally, this type of binding processing apparatus is known as an apparatus that performs binding processing on a bunch of sheets supported on a paper mount (sheet support section) as a post-processing apparatus in an image formation system, or the like. As a binding processing mechanism, known are a mechanism (staple binding mechanism) for binding a bunch of sheets with a staple, and a mechanism (press binding mechanism) for applying narrow pressure to a bunch of sheets with pressurizing surfaces having concavo-convex surfaces to perform press binding.
The press binding mechanism for performing binding processing on a bunch of sheets without using a metal needle is commonly used for a method of enabling bound sheets to be easily separated and divided and not affecting the environment in discarding documents. On the other hand, such a problem is also known that the sheet peels off when a bunch thickness of a bunch of sheets to perform binding processing is thick, page turning is performed vigorously or the like.
For example, Patent Document 1 discloses a press binding mechanism, and proposes the mechanism for increasing or decreasing a press binding region (press-binding area) corresponding to a bunch of sheets to perform binding processing. The Document discloses the mechanism that is a pressurizing mechanism in the shape of gears which rotate in a mutually meshing state in which by adjusting the rotation amount, strong binding is obtained when a band-shaped binding portion is long, and weak binding is obtained when the portion is short.
Further, in Patent Document 2, it is configured to enable strong binding or weak binding to be selected by changing the angle direction of a press binding pressurizing region. Then, in applying narrow pressure to sheets with a pair of pressurizing surfaces to perform press binding, the sheets are deformed in the shape of gathers. Binding easy to peel (weak binding) or binding hard to peel (strong binding) is selected by changing a mesh width (short-side direction) and mesh length (long-side direction) in the arrangement direction with respect to the sheet turning direction. | {
"pile_set_name": "USPTO Backgrounds"
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A phase-change thermal device is a device that is filled (i.e., charged) with a working fluid that changes to a vapor in response to thermal energy. Example phase-change thermal devices include, but are not limited to, a thermal switch or diode device, a vapor chamber, a heat pipe, and a thermal ground plane. In these devices, a chamber is filled with the working fluid. However, in miniature phase-change thermal device (e.g., devices charged with a working fluid volume of less than or equal to 1 ml), it may be very difficult to control the amount of working fluid injected into the device. In many cases, the volume of working fluid should be precisely controlled so that the phase-change thermal device may operate as desired.
Further, in the case of a thermal switch device, the vacuum level within the thermal switch device is controlled so that the thermal switch devices switches from relatively low thermal conductivity to relatively high thermal conductivity at a desired temperature. The thermal switch device is sensitive to the amount of non-condensable gas left within the chamber. Thus, the presence of non-condensable gas within the thermal device may lead to a non-controllable switching temperature of the thermal switch device.
Accordingly, a need exists for alternative systems and methods for degassing and charging phase-change thermal devices. | {
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Users may play or browse media in a media player and/or a media player user interface. Users may also be linked with other users in various social networking systems who may also play or browse media in a media player. Users may have an interest in learning about the media consumption habits of other users to which they are linked via social networking systems, or from whom they receive content in blogging networks, microblogging networks, and the like. | {
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1. Field of the Invention
The present invention relates to an image-forming-device management system which includes a local network in which an agent device is connected with one or more image-forming devices, such as copiers or printers, as well as a management device carrying out remote management of the image-forming devices using Internet connection of the local network. The present invention further relates to an image-forming-device management method, an image-forming-device management program and a storage medium thereof.
2. Description of the Related Art
A conventional image-forming-device management system carries out maintenance management of one or more image-forming devices at the user locations by operation of a remote management device, located at a remote place, through a communication line such as a telephone line.
In performing the remote management using the connection by telephone, the communication cost increases. In order to reduce the communication cost, it is possible to perform remote management using the Internet connection that is made to the remote management device by the user on the local network side.
On the other hand, in local networks, such as corporate networks, there is the possibility that any third person has illegal access, through an external network, such as the Internet, to internal data and programs within the local networks. To avoid this, the firewall is provided in many local networks so that alteration, destruction, etc. may not be performed to the data and programs in the local networks.
If the conventional image-forming-device management system is applied to such a local network, it is difficult to carry out remote management of the image-forming devices in the local network from the remote management device through the Internet, by the presence of the firewall in the local network.
When connecting the remote management device with the image-forming device in the local network having the firewall provided therein using the Internet connection of the local network, direct transmission of a processing request from the management device to the image forming device is impossible in many cases by the presence of the firewall.
The firewall permits the transmission of a request from the user's local network to the Internet and the transmission of its response from the Internet to the local network. However, the firewall does not permit the transmission of a request from the Internet to the user's local network because of the function of the firewall to avoid illegal accessing.
A conceivable method to eliminate the above problem is to change the setting of the firewall such that only a request from the management device to the image-forming device may be passed through the firewall.
However, such change of the firewall setting raises the possibility of making the security level of the firewall lower and increasing the network administrator's burden.
Another conceivable method to eliminate the above problem is to utilize VPN (virtual private network) device that allows only a request from the management device to pass through the firewall to the image-forming device. However, it is necessary to increase the device cost greatly for the use of VPN device in the image-forming-device management system.
Therefore, because of the presence of the firewall, it is difficult for the conventional image-forming-device management system to carry out remote management of the image-forming device in the local network from the management device connected through external networks, such as the Internet, without increasing the device cost greatly. | {
"pile_set_name": "USPTO Backgrounds"
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Memory devices are widely used to store information in various electronic devices such as computers, wireless communication devices, cameras, digital displays, and the like. Information is stored by programming different states of a memory device. For example, binary devices have two states, often denoted by a logic “1” or a logic “0.” In other systems, more than two states may be stored. To access the stored information, the electronic device may read, or sense, the stored state in the memory device. To store information, the electronic device may write, or program, the state in the memory device.
Various types of memory devices exist, including random access memory (RAM), read only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, and others. Memory devices may be volatile or non-volatile. Non-volatile memory, e.g., flash memory, can store data for extended periods of time even in the absence of an external power source. Volatile memory devices, e.g., DRAM, may lose their stored state over time unless they are periodically refreshed by an external power source. A binary memory device may, for example, include a charged or discharged capacitor. A charged capacitor may, however, become discharged over time through leakage currents, resulting in the loss of the stored information. Certain features of volatile memory may offer performance advantages, such as faster read or write speeds, while features of non-volatile memory, such as the ability to store data without periodic refreshing, may be advantageous.
FeRAM may use similar device architectures as volatile memory but may have non-volatile properties due to the use of memory cells that include a ferroelectric capacitor as a storage device. FeRAM devices may thus have improved performance compared to other non-volatile and volatile memory devices. However, typical approaches to accessing (e.g., reading, writing, etc.) FeRAM memory cells often utilize complicated circuitry and complicated sequences of internal control signals, which results in disadvantages in terms of circuit design and compactness, and power consumption. | {
"pile_set_name": "USPTO Backgrounds"
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The compound 2-(2-fluoro-4-biphenylyl)propionic acid--known as flurbiprofen--is a well known drug which possesses desirable anti-inflammatory, analgesic and anti-pyretic properties. Flurbiprofen and methods for its preparation are disclosed in U.S. Pat. Nos. 3,755,427 and 3,959,364 both assigned to the Boots Company, Ltd. The former discloses a method for its preparation by reacting an ester of the appropriate substituted 4-biphenylyl acetic acid with diethyl carbonate to give a malonic ester, methylating the sodium derivative of this ester, hydrolyzing the ester, and then decarboxylating the resulting acid. The latter patent discloses a process for the preparation of aryl propionic acids--including flurbiprofen--which comprises reaction of a Grignard compound, obtained from an aryl bromide and magnesium with a lithium, sodium, magnesium or calcium salt of 2-bromopropionic acid, followed by acidification. Japanese Kokai No. SHO 53-116,352 (Oct. 11, 1978) also discloses a method for the preparation of flurbiprofen by decarboxylation and hydrolysis of 2-carboalkoxy-2-(2-fluoro-4-biphenylyl)propionitrile.
Because of the beneficial properties of flurbiprofen, novel methods for its preparation are welcomed by the art. Such is provided by the present invention. | {
"pile_set_name": "USPTO Backgrounds"
} |
A method for operating a mobile wireless network is described in German Published Patent Application No. 199 44 334 in which data is assembled into at least one unit, particularly a packet data unit, by a first convergence protocol layer before transmission to a second convergence protocol layer, particularly on the same protocol level, with the data being supplied to the first convergence protocol layer by a user in a network layer. | {
"pile_set_name": "USPTO Backgrounds"
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Curved liquid crystal displays with the features of ultra-thin, light weight, flexible, high degree of freedom of design has broad market prospects in wearable, mobile communications, television, commercials and military applications. However, during the bending or folding of the curved liquid crystal display panel, due to the inconsistent compression of photo spacers, PS in different areas of the display area caused by the stress, the stress of the photo spacers in the middle area on the liquid crystals in the middle area is larger, thereby causing the liquid crystals in the middle area to diffuse to the edge regions on both sides, resulting in uneven distribution of the liquid crystal in the liquid crystal layer, so that the length of the liquid crystal layer in the edge region is larger than the length of the liquid crystal layer in the intermediate region. The difference in the length of the liquid crystal layer results in optical path difference, affecting the quality of the display. | {
"pile_set_name": "USPTO Backgrounds"
} |
Semiconductor memory devices are used extensively to store data. Memory devices can be characterized according to two general types: volatile and non-volatile. Volatile memory devices such as static random access memory (SRAM) and dynamic random access memory (DRAM) lose data that is stored therein when power is not continuously supplied thereto.
Non-volatile memory devices, such as flash erasable programmable read only memory (Flash EPROM) device, retain stored data even in the absence of power supplied thereto. Unfortunately, non-volatile memory devices typically operate more slowly than volatile memory devices. Accordingly, it would be desirable to provide a universal type memory device that includes the advantages of both volatile and non-volatile memory devices, i.e., fast operation on par with volatile memories, while having the ability to retain stored data when power is discontinued to the memory device. It would further be desirable to provide such a universal type memory device having a size that is not prohibitively larger than comparable volatile or non-volatile devices. | {
"pile_set_name": "USPTO Backgrounds"
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Various circuit topologies have been developed to control the flow of power and/or achieve efficient energy utilization in associated equipment. These technologies can generally be categorized as power electronics. The importance of power electronics in electrical equipment stems from its broad range of applications, including residential, industrial, commercial and communications devices to name a few.
Power electronics generally utilize one or more power converters to, for example, control and shape an input electrical signal into another electrical signal having different electrical characteristics, such as magnitude, frequency and/or the number of phases. With the continued advances in fabrication technologies, an increasing number of applications are making use of power converters, including power supplies as well as other power electronic converters or conditioners.
In some power converter applications, it is necessary to limit the maximum duty cycle of a signal generated by an associated pulse width modulator. For example, the pulse width modulator output signal is limited to a certain maximum duty cycle to avoid damage or failure of the power converter under various conditions, including transient and steady state conditions. The duty cycle controls the “on time” of the power converter. The possibility for damage of the power converter is due at least in part to the transformer's inability to demagnetize at large duty cycle ratios. That is, if the duty cycle becomes too large, the magnetic core can saturate and thereby cause permanent damage to the power converter circuitry. Similar concerns exist for other inductive applications. Accordingly, it becomes increasingly important to set a maximum duty cycle accurately. Thus, it becomes significant to limit the current in the inductor to avoid saturation. The flux in the inductor windings is proportion to the applied DC voltage and time, which electrical characteristics can be limited by a corresponding volt-second clamp.
Various approaches exist to limit a maximum duty cycle, typically including circuitry operative to clamp the output signal of the pulse width modulator. Operation of clamping circuitry can vary according to several factors, including, for example, accuracy and temperature stability of the clamp circuitry and associated reference voltages. The cumulative effect of such variations can amount to a sizeable tolerance in the maximum duty cycle setting.
One conventional approach for limiting maximum duty cycle is to average and compare the output signal of a pulse width modulation to a reference value. The reference value is proportional to the peak value of the comparator's output voltage. A closed loop circuit continually adjusts the duty cycle so the difference between the reference value and the average comparator output is substantially mitigated, which provides a maximum duty cycle output. Other approaches exist, but generally are unable to achieve a desired level of accuracy for either a maximum duty cycle clamp or volt-second clamp. | {
"pile_set_name": "USPTO Backgrounds"
} |
The present invention relates to a semiconductor device in which stress is applied to a channel region, and a method of manufacturing the semiconductor device.
Many reports on techniques for improving driving capability without depending on a scaling law have recently been given. The known techniques enhance driving capability by applying stress to a silicon region (for example a silicon substrate) in which a channel region is formed, and thereby increasing mobility of electrons and holes. As these techniques, a method has been put to practical use in which method a drain-source part is dug down by silicon etching, and a silicon compound having a different lattice constant from that of silicon (Si) is grown by an epitaxial growth method, whereby stress is applied to a channel (see Japanese Patent Laid-Open No. 2000-315789, for example).
In addition, various attempts have been made, including stress liner techniques that distort a channel by forming a covering of a silicon nitride film having stress after formation of the transistor, techniques that distort a channel by using a film having stress as a part of burying materials for STI (Shallow Trench Isolation), and the like.
The mechanism will be described with reference to a schematic diagram. FIGS. 10A and 10B show the three-dimensional directions of stresses most effective when applied to the respective transistors of a pMOSFET shown in FIG. 10A and an nMOSFET shown in FIG. 10B to distort a channel. Effective stress common to the NMOS and the PMOS is applied in a direction of stretching an active region in an x-direction.
A section in a gate width direction (a direction orthogonal to a source-to-drain region direction) of a two-dimensional type (planar) MOS transistor in related art will be described with reference to a schematic configuration sectional view of FIG. 11. It is known that as shown in FIG. 11, an insulating film (high density plasma (HDP) or the like) when buried in a trench 115 formed in a semiconductor substrate 111 to form an element isolation regions 113 of an STI structure has compressive stress. The stress applied to a channel region 114 of the transistor acts in a direction of degrading mobility (the direction of arrows).
On the other hand, as transistor generations have succeed, many researches have been conducted into transistors having a three-dimensional structure in place of the two-dimensional type (planar) transistor in related art. A typical transistor is referred to as a fin gate transistor, in which a gate electrode is disposed on a silicon substrate with a gate dielectric interposed between the gate electrode and the silicon substrate, the gate dielectric covering a channel region part of a fin part formed so as to be projected in the shape of a fin (see Japanese Patent Laid-Open No. 2006-12924, for example). In addition, a tri gate transistor using, as a channel, not only an upper side surface of a semiconductor substrate in which a trench is formed but also a side wall part of an upper side of the trench has been reported (see Japanese Patent Laid-Open No. 2002-198532, for example).
FIG. 12 is a three-dimensional schematic diagram of an ordinary MOS transistor. FIG. 13 is a vertical sectional view including a line A-A′ of FIG. 12. When silicide layers 131 and 132 for lowering resistance are formed on the surfaces of source-drain regions 127 and 128 in a transistor 101 having a structure in which a channel region 114 and the source-drain regions 127 and 128 project from the surface of a semiconductor substrate 111, as shown in FIGS. 12 and 13, a leak occurs as a result of the silicide layers 131 and 132 being close to or in contact with the PN junction of the source-drain regions 127 and 128 formed by ion implantation and projected from the surface of the semiconductor substrate 111. | {
"pile_set_name": "USPTO Backgrounds"
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In recent years, a vehicle such as an electric vehicle and a hybrid vehicle equipped with a motor for driving the vehicle and a battery for driving the motor has been actively developed as an environmentally-friendly vehicle.
Japanese Patent Laying-Open No. 07-194015 (Patent Document 1) discloses a charge control device for charging a battery mounted in an electric vehicle. The charge control device receives an input of the detected value of each of an abnormality detection sensor and a current sensor. When determining that the battery normally operates, the charge control device feeds back the value of the current sensor so as to adjust a power control unit to supply an optimum charging current to the battery for performing charging. In the event of detection of the state where the battery should not be charged, such as a state where an abnormality occurs in the battery or the battery is fully charged, the electric power output from the power control unit is adjusted such that the detected value of the current sensor is approximately equal to 0. Accordingly, the electric power supplied to the fan and the like operating when an abnormality occurs in the battery is directly supplied from the charge control device, but not discharged from or supplied to the battery having an abnormality or fully charged. Patent Document 1: Japanese Patent Laying-Open No. 07-194015 | {
"pile_set_name": "USPTO Backgrounds"
} |
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