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In the related art, controlling a robot with robot vision has required a process of calibrating a robot coordinate system and a coordinate system of a capturing unit. During calibration, the position of a reference point in a space where a robot is installed is specified in each of the robot coordinate system and the coordinate system of the capturing unit, and a matrix for transforming the position of the reference point represented in one coordinate system into the position of the reference point represented in the other coordinate system is obtained. According to the technology disclosed in JP-A-8-210816, calibration is performed by teaching reference points in the robot coordinate system by moving an arm to touch three reference points and then by capturing markers that indicate the reference points with the capturing unit that is moved by the arm to a predetermined position and by detecting the reference points in the coordinate system of the capturing unit.
According to the technology disclosed in JP-A-8-210816, teaching the positions of the reference points is required by an operation of the arm by an operator to touch the three reference points. However, it is not easy to accurately operate the arm while visually specifying whether the arm touches the reference points or not. That is, the technology disclosed in JP-A-8-210816 has a problem in that it is not easy to accurately teach the positions of the reference points. Another problem arises in that a necessary time required for calibration is prolonged when calibration is performed with accurate teaching of the positions of the plurality of reference points. As the number of calibration target robots increases, this problem becomes worse. | {
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The present invention relates to a silica insulation film with a reduced dielectric constant and a method of forming the same, as well as relates to a silica inter-layer insulator with a reduced dielectric constant between multi-level interconnections in a semiconductor device and a method of forming the same, in addition relates to a semiconductor device with a multi-level interconnection structure having a silica inter-layer insulator with a reduced dielectric constant and a method of fabricating the same.
With an increase in density of integration of ultra large scale integrated circuit, the feature size of integrated semiconductor devices has been reduced to submicron order and also multi-level interconnection techniques become more important. In order to electrically isolate the different level interconnections, an inter-layer insulator is provided between the different level interconnections. The inter-layer insulator is required to possess a high stability at high temperature and a high electrical insulation property, in addition a good gap filling property. In prior art, a silica film or a silicon dioxide film, a silicon nitride film and a phospho-silicate glass film were, for example, used as inter-layer insulators between different level interconnections. Those inter-layer insulators were usually formed by various chemical vapor deposition methods.
In recent years, requirement for a further shrinkage of the feature size of integrated semiconductor devices has been on the increase in accordance with design rules of advanced large scale integrated circuits. The further shrinkage of the feature size of integrated semiconductor devices has raised a serious problem with delay in signal transmission on interconnections due to a parasitic capacitance between the interconnections rather than signal delay of individual devices integrated. The improvement in high speed performance of the large scale integrated circuit would be limited by the problem with delay in signal transmission on interconnections due to a parasitic capacitance between the interconnections even if a considerable shrinkage of the feature size of integrated semiconductor devices could be realized.
In order to realize a further improvement in high speed performance of the large scale integrated circuit, it is important to reduce the parasitic capacitance between the interconnections as many as possible. Since the parasitic capacitance between the interconnections depends upon a dielectric constant of the inter-layer insulator. Namely, in order to reduce the parasitic capacitance between the interconnections, it is required to reduce the dielectric constant of the inter-layer insulator. The silica film is advantageous in matching with LSI processes but is was difficult to largely reduce the dielectric constant from ∈ r=3.9.
In 1994 Dry Process Symposium pp. 133., it is disclosed to have proposed introduction of fluorine into a silica film to attempt to reduce the dielectric constant. In order to reduce the dielectric constant to about 3.5, it is required to add fluorine into the silica film at several tends percents, whereby the silica film exhibits a hygroscopic property and also a hydrolysis of fluorine is caused. As a result, fluorine is unstable in the silica film. For this reason, it was difficult to reduce the dielectric constant of the fluoro-containing silica film to less than about 3.5.
It is disclosed to have proposed the use of spin coating method to deposit a spin-on-glass film. This spin-on-glass film has a problem with residual solvent or a residual moisture.
In Japanese laid-open patent publication No. 8-227888, it is disclosed to have proposed to add an alkyl group into the silica film by a chemical vapor deposition method. The alkyl group is, however, unstable at high temperature.
In the above circumstances, it had been required to develop a novel silica film free from the above problems and a method of forming the same. | {
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Osteoporosis, a severe aging disease of the skeleton, gains ever growing importance due to the continuously increasing life expectancy. The annual cost to the health care system due to osteoporosis is estimated to amount up to several billions worldwide, in Germany one estimate is about 1 billion. Clinical and measurement efforts for an early diagnosis and efficient control of therapy are accordingly high.
Two procedures have shown to be particularly suitable for bone mineral measurements:
Photon absorptiometry (DXA, Dual Energy X-ray Absorptiometry) and quantitative computed tomography (QCT). For each modality there are more than 1000 installations of various manufacturers in use worldwide.
A particular problem and serious controversies have evolved from the fact that results which have been obtained on different units do not agree or can hardly be compared, respectively. In particular, for the DXA scanners, each manufacturer uses different phantoms both for calibration and for quality control. Due to the fact that different materials and different geometries are employed, calibrations are different Differences result for measurements of the same object or patient on different apparati. The phantoms available mostly offer homogeneous bone without separation of spongious and cortical portions. Due to their anthropomorphic shape, it is not possible to determine if the presented area values and the directly resulting area density values are correct.
In QCT, the manufacturers do not offer anthropomorphic phantoms. There are only some smaller specialized companies which offer such phantoms. These are not useful for direct comparison to DXA; also, they do not offer defined cortical structures. Since so far only solutions specific to one manufacturer and one scanner type have been offered, controversies resulted, but no accepted solution to the problem of cross-calibration of different devices. In addition, it has to be stated that the phantoms offered by small specialized companies are very expensive, partly not very practical and they do not offer all the desired test procedures.
It appears desirable to have only one phantom to simulate bone mineral measurements of the lumbar spine with both absorptiometry and QCT. It will help to reduce cost to have only one phantom instead of two different ones in those institutions who use both modalities. More important, however, is the intent to avoid a diversity of different phantom geometries and materials. This would be counterproductive in any standardization effort, and it might reinforce confusion or irritations in the user community.
For DXA, both a.p. and lateral measurement capabilities have to be provided. For QCT, separate measurement of spongious and cortical bone is required. The phantom should allow testing of reproductibility and accuracy of machines, both in clinical installations and at manufacturers' sites, in determining the following quantities:
projected area of vertebrae in cm.sup.2 for DXA, PA1 bone mineral content (BMC) in g for DXA, PA1 trabecular and cortical bone mineral density in g/cm.sup.3 for QCT, PA1 cortical thickness in mm for QCT, PA1 positioning in QCT. PA1 for all of the above measurements, the true values have to be known and defined in an objective manner; PA1 the phantom has to be designed in a way such that results of phantom measurements model the situation of patient measurements appropriately.
Bone mineral area density (BMD) in g/cm.sup.2, which is the quantity most often quoted in DXA, results directly from the above. Tests of linearity have to be provided also and require that the phantom offers either multiple sections or multiple inserts. The respective sections of inserts should cover the range of density values typically encountered in patients.
To perform appropriately, two general demands on the phantom must be met:
The first demand is absolutely necessary for the phantom to be used as a standard. The second demand is a logical one if the phantom is to give relevant results; in a particular, this means that cross-calibration factors obtained on the phantom have to be transferable to patient measurements. | {
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1. Field of the Invention
Embodiments of the invention relate to the field of semiconductor, and more specifically, to semiconductor materials.
2. Description of Related Art
The next generation die interlayer dielectric (ILD) materials are porous and have poor mechanical strength. To reduce the stresses on the ILD due to coefficient of thermal expansion (CTE) mismatches between materials in the package, low CTE materials are needed. In addition, due to the need for materials to flow over greater distances through narrower gaps, there is a need to eliminate, or minimize the concentration of, the filler, which is typically used to reduce the CTE.
Existing techniques to reduce the CTE and at the same time reduce or eliminate the concentration of the filler has a number of disadvantages. One technique increases the cross-link density and/or increases the filler loading of the dielectric material. This technique leads to high modulus and high viscosity, resulting in cohesive and adhesive failure modes. | {
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In the past a large amount of work has been devoted to the manufacture of sulphur-containing fertilizers. The growing worldwide demand for sulphur-containing fertilizers stems from the discovery that low crop yields in certain cases may be related to deficiencies in sulphur in the soil. An example of a species with high sulphur requirements is Canola. Canola is an important cash crop in Alberta, Canada, and has high sulphur requirements at any growth stage. A shortage of sulphur can cause serious reductions in crop yield and quality.
Manufacturing processes for sulphur-containing fertilizers of the ammonium phosphate type often involve the use or incorporation of sulphates, see e.g. U.S. Pat. No. 4,377,406, or U.S. Pat. No. 4,762,546. A disadvantage of sulphates is that they are very mobile in the soil and easily leach out of the root zone, effectively making the sulphate nutrient unavailable to the plants.
Elemental sulphur is not leached out of the soil, as sulphates are. Instead, micron sized elemental sulphur particles are oxidized to sulphate sulphur, which is the form utilized by the plants, by soil bacteria during the cropping season. Elemental sulphur is, thus, considered a slow release form of plant nutrient sulphur that is less prone to leaching out of the crops root zone. It is, therefore, advantageous to have a large proportion of the sulphur in fertilizers present as elemental sulphur. Furthermore, elemental sulphur offers some additional benefits in agriculture, including acting as a fungicide against certain micro organisms, acting as a pesticide against certain soil and plant pests, assisting the decomposition of plant residues and improving phosphorus and nitrogen nutrient utilization and reducing the pH of alkaline and calcareous soils.
Thus, it is advantageous to incorporate sulphur in sulphur-containing fertilizers as elemental sulphur present as small particles.
Processes for the manufacture of sulphur-containing fertilizers, wherein elemental sulphur is used, are known in the art. Most of the methods involve the incorporation of molten sulphur into the fertilizer.
In U.S. Pat. No. 5,653,782, a process for the manufacture of sulphur-containing fertilizers has been described, wherein a substrate containing fertilizer particles is heated to a temperature above the melting point of sulphur and admixed with sulphur. According to U.S. Pat. No. 5,653,782, the sulphur is melted by the heat provided by the preheated fertilizer particles, thereby producing a homogeneous coating on the fertilizer particles.
U.S. Pat. No. 3,333,939, describes the coating of ammonium phosphate granules with molten sulphur. The granules are coated in a separate coating unit into which the sulphur is fed, by contacting the granules with molten sulphur or with a solution of ammonium polysulphide. Subsequently, the coated granules are dried.
Alternatively, U.S. Pat. No. 3,333,939 teaches a process for preparing sulphur-containing fertilizer particles in which the sulphur is interspersed throughout the particles. In this process ammonia and phosphoric acid are allowed to react to form ammonium phosphate. The ammonium phosphate formed is fed into a granulator in which it is mixed with urea and dry sulphur. The granules obtained are dried in a dryer.
The disadvantage of the first process of U.S. Pat. No. 3,333,939 is that the coating prevents a uniform distribution of ammonium sulphate and sulphur into the soil. The second process has the disadvantage that it requires solid sulphur handling. The handling and grinding of solid elemental sulphur is highly hazardous due to the generation of sulphur dust and risks of sulphur dust fires and explosions. As mentioned in a review by H. P. Rothbaum et al (New Zealand Journal of Science, 1980, vol. 23, 377), explosion hazards are always due to sulphur dust which is inflammable. Therefore, a complex process design is necessary to ensure the safety of the process.
U.S. Pat. No. 5,571,303 discloses a process for the manufacture of fertilizers in which first ammonia, water and phosphoric acid are reacted to form ammonium phosphate. Subsequently, the ammonium phosphate/water mixture is mixed with molten sulphur. The mixture thus obtained is kept at temperatures of 120-150° C. until granulation. A disadvantage of this process is safety, that is elevated sulphur concentrations in process dusts may lead to potentially explosive dust-air mixtures.
EP 1560801 A1 discloses a process for the manufacture of sulphur-containing ammonium phosphate fertilizers comprising combining elemental sulphur, in the liquid form, with ammonia, phosphoric acid and water.
Several prior art documents, e.g. GB 1312314, US 2002/0139158, WO 97/16396, WO 02/090295, U.S. Pat. No. 5,423,897 and U.S. Pat. No. 3,926,841 have disclosed the use of coating agents, incorporating surfactants, in the reduction of dust formation and caking during use and handling of NPK-type fertilizers.
WO 2008/024007 discloses a sulphur fertilizer, either in the form of globular granules or pellets that constitutes solidified mixtures of liquid sulphur and bentonite, and favourable additional components and fertilizing microelements, that is characterised by its content of 60 to 95% of sulphur, 4 to 20% bentonite and 1 to 8% lignosulphonate. The lignosulphonate is incorporated into the sulphur fertilizer molecules in order to allow the formation of granules or pellets which disperse easily in contact with soil moisture into sulphur molecules of much smaller size than known fertilizers of this type.
GB 2292140 also discloses sulphur/bentonite fertilizer compositions in which 1 to 30 wt. % of a binding material, such as a lignosulphonate, may be added in order to form suitable granules for application of sulphur to the land.
US 2004/0009878 describes particles containing a nitrogen-containing fertilizer composition, preferably based on urea, in which a binder component, such as a lignosulphonate, is present such that contact of the particles with water causes particle dispersion into more than 100 pieces.
WO 90/03350 discloses a sulphur-based chemical soil-corrective in the form of pellets for agricultural use, said product comprising fly sulphur powder, at least 3 wt. % of an inert product selected from the group consisting of clay, bentonite, kaolin and mixtures thereof, and at least 0.5 wt. % of a wetting agent, said components being mixed with one another and subjected to wet extrusion and subsequent drying to obtain said pellets. The wetting agent may be a lignin sulfonate. However, as WO 90/03350 relates to the handling of sulphur powder which is subjected to extrusion (rather than granulation as used according to the present invention) the teachings therein are not relevant for the process according to the invention.
Regardless of the improvements disclosed in the art, problems with the manufacture of phosphate-based fertilizers containing elemental sulphur, continue to be in existence. In particular, dust and explosion hazards involving elemental sulphur dust continue to be of great concern. Therefore, there remains a need for fertilizers and manufacturing processes for such fertilizers which would diminish or even prevent the safety problems experienced in the art. | {
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The present invention relates in general to metal plating processes and, more particularly, to a process for generating a patterned metal layer on an insulating substrate in the fabrication of semiconductor integrated circuits.
In the production of semiconductors, it is often necessary to form patterned metal layers on the semiconductor or insulator surface to provide conductive areas that transfer electrical current. Typically, such patterned layers are produced in one of two ways. One way is to use the desired pattern to form a mask and then to deposit the metal onto the dielectric or insulator in the desired pattern through the mask.
In the alternative, the metal is deposited as a continuous, un-patterned layer over the dielectric surface. The deposition of the continuous metal layer may be done in any one of a number of ways, including vacuum deposition, sputtering, and electrolytic or electroless plating, to name a few. The continuous metal layer is later selectively etched using a process such as photolithography, to generate a desired metal pattern. Photolithography is a process in which a light source illuminates a circuit pattern and projects the image through a lens assembly onto a semiconductor wafer or substrate. Ultimately, the circuit pattern is etched into the wafer.
All processes have advantages and disadvantages and some are better suited than others for a particular purpose. The need for circuits offering higher performance, which often means higher speeds, has resulted in a need for conductive elements with high conductivity so as to minimize losses. As a result, copper, with its high conductivity, has become a desirable metal to be used in integrated circuit applications replacing the traditional aluminum conductors.
Copper and copper alloys exhibit superior electromigration properties and have a lower resistivity than aluminum. Thus, copper and its alloys are useful in very large scale integration (VLSI) interconnect metallizations (i.e., more than 100,000 devices per chip). In addition, copper has improved electrical properties when compared to tungsten, making copper a desirable metal for use as a conductive plug as well as conductive wiring. There are also disadvantages, however, attendant upon the use of copper For example, copper readily diffuses through silicon dioxide, the typical dielectric interlayer material used in the manufacture of semiconductor devices, and adversely affects the devices.
From the manufacturing point of view, patterned copper or copper alloys are difficult to produce. For one, copper etching is problematic. Wet chemical etchants etch isotropically and generally permit insufficient dimensional control for sub-micron devices. Dry etching is typically used, but some metal layers, such as copper and gold, are difficult to plasma etch or reactive ion etch at reasonable production temperatures. During the chemical etching, the metal layer to be patterned is inevitably subjected to what is called xe2x80x9cside etchingxe2x80x9d by an amount dependent upon the length of chemical etching, resulting in the patterned metal layer becoming smaller than the pattern of the mask layer by the amount of side etching. The amount of side etching depends upon the temperature, the flow rate, and other conditions of the etchant used; therefore, it is very difficult to predict the amount of side etching. The subtractive etching process is not currently used to form patterned layers of copper because of the difficulties associated with chemical and plasma etch processes.
When copper is used as the metal for conductors in a patterned metal layer, the typical process involves depositing a conformal barrier layer on the dielectric substrate, usually a tantalum layer, using chemical vapor deposition. The barrier layer prevents copper diffusion into the dielectric. Over the barrier layer there is next deposited a thin layer of copper metal to provide a seed layer having high conductivity. The coated substrate is placed next in a standard electrolytic bath and connected to a voltage source while a source of copper is also in the bath connected to the same voltage source. Uniform electrolytic deposition over the seed layer is accomplished by passing a current through the system.
This technique produces a uniform layer of copper over the seed layer with good adhesion to the barrier layer The photolithography and etching processes, with their related problems discussed above, are used to generate the desired conductive pattern. The deficiencies of the conventional processes show that a need still exists for a process for direct deposition of preferred metals patterned onto dielectric substrates without having to produce a continuous layer that is subsequently etched to form a desired pattern.
To meet this and other needs, and in view of its purposes, the present invention provides a metal layer plating process that yields a patterned metal layer on an upper surface of a dielectric layer without masking or etching steps. More specifically, the present invention provides a process for controlling the electrolytic deposition of a first metal, such as aluminum, nickel, cobalt, silver, gold, palladium, platinum, rhodium, or copper; alloys of copper, of aluminum, of cobalt, of silver, of gold, of palladium, of platinum, of rhodium; and combinations of these metals and alloys, on a barrier layer comprising a refractory metal. The process comprises forming a first patterned conductive layer on a support, forming a dielectric layer over the support and conductive pattern, and forming a continuous barrier layer over the dielectric layer. The first patterned conductive layer may be an inductor, in the process of the present invention, or it may be a non-inductive conductive line pattern, such as a serpentine pattern. The process further comprises applying a current to the barrier layer while the barrier layer is immersed in an electrolytic bath.
Still more specifically, the process for forming a patterned metal layer on an upper surface of a dielectric layer comprises, according to the present invention, the following steps:
(a) forming a first conductive pattern on a substrate;
(b) forming a dielectric layer over the first conductive pattern and the substrate;
(c) forming a conformal barrier layer comprising a refractory metal on the upper surface of the dielectric layer; and
(d) electroplating directly on the barrier layer a metal selected from the group consisting of aluminum, nickel, cobalt, silver, gold, palladium, platinum, rhodium, or copper; alloys of copper, of aluminum, of cobalt, of silver, of gold, of palladium, of platinum, of rhodium; and combinations of those metals and alloys, by flowing a current through the barrier layer while immersing the barrier layer in an electroplating bath, the deposited metal forming a patterned layer during the deposition.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the invention. | {
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It is known that a polymer having an alkenyl group at a molecular chain terminus undergoes crosslinking either by itself or in the presence of a curing agent such as a hydrosilyl-containing compound to give a heat-resistant, durable cured product. The main chain structure of such a polymer, so far known, includes polyether series polymers such as polyethylene oxide, polypropylene oxide, polytetramethylene oxide, etc.; hydrocarbon series polymers such as polybutadiene, polyisoprene, polychloroprene, polyisobutylene, etc., inclusive of hydrogenation products thereof; polyester series polymers such as polyethylene terephthalate, polybutylene terephthalate, polycaprolactone, etc.; and polysiloxane series polymers such as polydimethylsiloxane, among others, and these polymers have been used in various applications selectively according to the characteristics of the respective main chain structures.
Vinyl polymers have several characteristics not shared by the above various polymers, such as high weather-resistance, heat resistance, oil resistance and transparency, among others, and the use of the polymers having side-chain alkenyl groups has been advocated in the field of weather-resistant coatings (e.g. Japanese Kokai Publication Hei-3-277645; Japanese Kokai Publication Hei-7-0399).
However, alkenyl-terminated vinyl polymers cannot be easily produced and, therefore, have not been much employed on the industrial scene as yet.
Japanese Kokai Publication Hei-1-247403 discloses a process for producing an acrylic polymer having an alkenyl group at both termini which comprises using either an alkenyl group-containing dithiocarbamate or diallyl disulfide as the chain transfer agent.
Further, Japanese Kokai Publication Hei-6-211922 discloses a process for producing an alkenyl group-terminated acrylic polymer which comprises preparing a hydroxyl group-terminated acrylic polymer using a hydroxyl group-containing polysulfide or an alcoholic compound as the chain transfer agent in the first place and taking advantage of the reactivity of the hydroxyl group so introduced.
Meanwhile, curable compositions adapted to give rubber-like elastic products on curing have been used broadly in the field of adhesive, sealing and shock-absorbing materials. These compositions can be roughly classified by the mode of curing into the so-called moisture-curable compositions which are stable in a sealed environment but cure in the atmosphere by absorbing its moisture even at room temperature to give rubber-like elastic products and those compositions which are adapted to crosslink through hydrosilylation or the like reaction on exposure to heat.
However, by the above prior art technology, it is difficult to introduce an alkenyl group into the polymer terminus with good reproducibility. Moreover, since the standard radical polymerization reaction is utilized in these processes, there is the problem that the molecular weight distribution (the ratio of weight average molecular weight to number average molecular weight) of the product polymer is as broad as 2 or more and, therefore, the viscosity of the polymer is high. In utilizing the polymer as a sealant or an adhesive, for instance, such a high viscosity makes it difficult to handle the polymer and, moreover, a filler for reinforcement cannot be formulated in a sufficient amount.
It has also been found difficult to introduce a (meth)acryloyl group, which has radical polymerization activity, into a vinyl polymer which is synthesized by radical polymerization. Particularly, few compounds with a (meth) acryloyl group introduced into the oligomer terminus have so far been successfully synthesized.
In many of photocurable compositions so far available, a low molecular compound having a (meth)acryloyl group is employed. In such cases, the odor caused by vaporization of the unreacted low-boiling compound during and after curing has been a serious problem. To avoid this trouble, an oligomer having a (meth)acryloyl group is employed. However, chiefly from synthetic points of view, such oligomers are limited to epoxy-acrylate, urethane-acrylate, polyester-acrylate and the like systems. Moreover, oligomers having large molecular masses are not available. As a result, such compositions tend to give comparatively hard cured products and do not give cured products having good rubber-like elasticity.
In view of the above state of the art, the present invention has for its object to provide a vinyl polymer having a reactive functional group at a molecular chain terminus at a high rate and a curable composition comprising the polymer. | {
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Conventional vertical axis wind turbines (VAWTs) are wind turbines that comprise multiple rotor blades that can rotate, when impinged upon by wind, about a vertical axial rotor shaft. One configuration that VAWTs can take is the conventional “egg-beater” Darrieus-type VAWT described in U.S. Pat. No. 1,835,018. VAWTs have several advantages over horizontal axis wind turbines. For example, VAWTs do not need to be pointed into the wind. Thus, they do not require complex yaw control mechanisms. Further, generators and gearboxes can be located close to the ground. This allows, for example, easy access to these components for maintenance and eliminates the need for a large support tower to hold these components off the ground.
However, VAWTs have susceptibilities of their own to overcome. VAWTs are typically supported by a set of guy-wires that hold the turbine in its vertical orientation and stabilize the VAWT against, for example, large gusts of wind and vibrations that occur as the rotor blades rotate. The guy-wires typically extend directly from the top of the vertical axial rotor shaft to the ground and exert compressive forces on the central tower supporting the turbine assembly. These forces are borne by the lower bearing assembly, which is already carrying the weight of the VAWT. This additional load can reduce the lifetime of the lower bearing assembly.
In addition, VAWTs are susceptible to dynamic stall. FIG. 1 shows a schematic transverse section of a VAWT with a rotor blade 110 located at various possible azimuthal angles 111-118 (θ=0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° respectively) about a vertical rotational axis 120. Eight blades are shown to illustrate eight respective azimuthal angles. In many embodiments, the transverse section at a given instant in time would reveal any two blades on opposing respective sides of the vertical axis 120, as will be described below. As the rotor blade 110 rotates clockwise about the vertical axis 120, the rotor blade 110 experiences varying angles of attack α relative to incident wind. The angle of attack α is the angle between the oncoming wind and the chord of the rotor blade. The oncoming wind vector is the vector sum of the incident wind velocity vector and the velocity of a rotating rotor blade. At low angles of attack, air flows smoothly over the surfaces of the rotor blade 110 and the blade experiences lift, which is useful for urging continued rotation of the blade 110 about the vertical axis 120. This lift increases with increasing angle of attack up to an angle at which flow separation begins at the rotor blade. When the flow of air begins to separate from a blade surface, lift no longer increases; in fact, lift may drop suddenly while large eddy currents are generated in the blade's wake. Thus, there is a critical angle of attack at which blade experiences maximum lift. As the angle of attack α continues to increase, the flow of air in the blade's wake becomes increasingly turbulent. At attack angles beyond the critical angle, the lift and pitching moments experienced by the blade 110 decrease sharply and are accompanied by a large increase in drag, as the rotor blade stalls. The ability of a VAWT to generate power is reduced whenever one or more rotor blades experience stall conditions, and rapid changes in the pitching moment can be destructive to the VAWT. Thus, it is desirable that stall conditions be avoided, or at least minimized.
VAWT stall conditions experienced by rotor blades are dynamic in that the blades can transition in and out of regions where stall conditions are experienced as the VAWT rotates about its vertical rotational axis 120. The regions where rotor blades experience stall conditions as it rotates about the vertical rotational axis 120 are referred to as “dynamic stall regions.” Rotor blade 110 experiences dynamic stall regions 130, 140. The rotor blade 110 does not have to transition in and out of the dynamic stall regions 130, 140 at any specific azimuthal angles suggested by FIG. 1. Rather, FIG. 1 is meant to show that VAWT rotor blades experience stall conditions at the highest angles of attack, or, when the rotor blade 110 is at azimuthal angles in respective regions about θ=90 degrees and θ=270 degrees (FIG. 1). In this specification, the terms “stall” and “dynamic stall” are used interchangeably. In a conventional Darrieus VAWT design, dynamic stall can start near the top of a vertical axial rotor shaft (vertical support column) where the tip speed ratio (i.e., the ratio of the rotational speed of the rotor blades to the wind speed) is lowest. Thus, the upper portion of Darrieus VAWTs can operate in dynamic stall conditions for a large portion of time during each revolution.
One way of reducing dynamic stall is to reduce the angular width of the dynamic stall regions. To such end, the effects of various active flow control techniques on boundary layer separation have been studied. “Active flow control” refers to the injection or removal of air to the flow of air over an airfoil surface. For example, the application of periodic excitation (alternating blowing and suction) as an active control of separation technique on NACA 0015 airfoils has been studied. D. Greenblatt et al., “Dynamic Stall Control by Periodic Excitation, Part 1: NACA0015 Parametric Study” Journal of Aircraft, Vol. 38, pp. 430-439, 2001. In addition, flight tests have been performed to assess the effectiveness of using electromagnetic actuators for active flow control in tiltrotor aircraft. A. McVeigh et al., “Model and Full Scale flight Tests of Active Flow Control on a Tilt Rotor Aircraft,” (presented at the American Helicopter Society 60th Annual Forum, Baltimore, Md., Jun. 7-10, 2004). However, these active flow control approaches involve the use of actuators that can be complex, heavy, and hard to maintain because of multiple moving parts and that require the consumption of power to operate. Thus, these approaches can be costly, in terms of both initial manufacturing and on-going maintenance expenses. | {
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To meet the huge demand for data centric applications, Third Generation Partnership Project (3GPP) systems and systems that employ one or more aspects of the specifications of the Fourth Generation (4G) standard for wireless communications will be extended to a Fifth Generation (5G) standard for wireless communications. Unique challenges exist to provide levels of service associated with forthcoming 5G and other next generation network standards. | {
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1. Field of the Invention
The present invention relates to a substrate carrying apparatus, a substrate carrying method, and a coating and developing apparatus equipped with the substrate carrying apparatus, for carrying substrates having subjected to a process in which a liquid remains on a periphery of the rear face of each substrate, such as a dipping exposure process.
2. Background Art
Conventionally, in a photo-resist process, which is one of the processes for manufacturing semiconductors, semiconductor wafers (hereinafter referred to as wafers) are coated with a resist on their surfaces; and the resist is exposed to light through a predetermined pattern, and thereafter a developing liquid is supplied to the wafers to develop and form a resist pattern. This process is performed using a system in which an exposure machine is connected to a processing block of a coating and developing apparatus generally including a coating unit and a developing unit.
Transferring wafers from the processing block to the exposure machine or from the exposure machine to the processing block is performed via an interface residing between the processing block and the exposure machine. In the interface, for example, two substrate carrying apparatuses are provided.
In recent years, an exposure technique, referred to as a dipping exposure process, has been studied for the purpose of enhancing resolution of exposure due to the need for micromachining and thin-film forming of device patterns. What is meant by a “dipping exposure process” is an exposure process in which a liquid layer, such as a layer of ultra-pure water, is first formed for transmitting light through the layer onto a surface of a wafer, and the wafer surface is then irradiated with light generated from a light source through the liquid layer, whereby a predetermined circuit pattern can be transferred to a resist on the wafer surface. More specifically, if, for example, ArF is used as a light source for performing the exposure process, the wavelength of light generated from the light source is 193 nm in the air, but becomes substantially 134 nm in water. Thus, in this technique, a high resolution exposure process can be performed by utilizing such a phenomenon that the wavelength of light becomes short in water.
An exposure apparatus adapted to perform such a dipping exposure process is briefly explained with reference to FIG. 12. An exposure means 1 facing a wafer W with a gap is arranged above the wafer W held in a horizontal position by a holding means (not shown). A lens 1a is provided in a central distal end of the exposure means 1, and a supply port 1b for supplying a solution, for example, pure water, for forming a liquid layer on the surface of the wafer W and a suction port 1c for suctioning and recovering the pure water supplied to the wafer W are arranged around the outer periphery of the lens 1a. In this case, by supplying pure water to the surface of the wafer W from the supply port 1b while recovering pure water from the suction port 1c, a liquid film or layer (pure water film) can be formed between the lens 1a and the surface of the wafer W. Thereafter, light is emitted from a light source (not shown), passes through the lens 1a, and is then transmitted through the liquid film onto the wafer W, whereby a predetermined pattern can be transferred to a resist.
Subsequently, in the state where the liquid film is formed between the lens 1a and the wafer W, the exposure means 1 is moved sliding on the wafer W so that the exposure means 1 can be located at a position corresponding to a next transfer region (shot region). Thereafter, by repeating the irradiating operation with light, the circuit pattern can be transferred successively to the surface of the wafer W.
In a wafer just after being subjected to such a dipping exposure process, a liquid, for example, pure water, used for the exposure process travels, as shown in FIG. 3, from the surface through the peripheral end face to a portion on the rear face, thus forming a liquid drop 11. The extent in which the liquid drop 11 is attached to the rear face of the wafer W is ranging from the peripheral end of the wafer W to a 2 mm inside position. In FIG. 13, reference numeral 12 denotes a resist film formed on the wafer W.
FIG. 14 shows a situation at a front end portion of a carrying arm which has been studied to carry the wafer W just after being subjected to the aforementioned dipping exposure process. In the drawing, reference numeral 13 designates an arm body and reference numeral 14 denotes a nail portion provided at a front end portion of the arm body 13. To the nail portion 14, a restricting portion 15 for controlling the position of the periphery of the wafer W is provided. A raised restricting face 15a disposed inside the restricting portion 15 is configured to face the peripheral end face of the wafer W, which is placed on the arm body 13, and adapted to control the position of the periphery of the wafer W. At the lower end of the restricting face 15a, a supporting face 16 for supporting the wafer W is provided in succession, for example, in a generally horizontal direction. On the further inside of the supporting face 16 provided in the nail portion 14, a downwardly inwardly inclined face 17 is provided.
The arm body 13 is operated such that it can scoop up the wafer W placed on, for example, a stage (not shown) provided in an exposure apparatus so as to place the wafer W on the supporting face 16 (FIGS. 14(a), 14(b)). In FIG. 14(b), the length from the peripheral end of the wafer W contacting with the supporting face 16 to the front end of the supporting face 16 is, for example, about 1 mm. When the wafer W is placed on the supporting face 16 in such a manner, the liquid forming the liquid drop 11 at the lower periphery of the wafer W is forced to move to the corner between the supporting face 16 and the restricting face 15a. Thereafter, when the wafer W is separated from the arm body 13 as shown in FIG. 14(c), the liquid 18 forced to move to the corner tends to remain attached to the corner due to the surface tension. Thus, by repeating such an operation, the liquid 18 remaining at the corner is gradually accumulated.
However, if the remaining liquid 18 is accumulated in such a manner, either by impact occurring when the arm body 13 receives a next wafer from the exposure apparatus, or by vibration of the arm body 13 carrying a next wafer after having received it, the liquid 18 may tend to scatter into the air and be attached again to the next wafer W. If water drops are attached to the surface of the wafer W, the temperature of each site to which the water drop is attached or of another site in which a water mark is produced becomes different from that of other sites upon a subsequent heating process, resulting in deterioration of the uniformity in the resist pattern face. Although it may be possible to wash the wafer W prior to heating, it is quite difficult to remove micro-water drops. Therefore, it is necessary to avoid the attachment of water drops to the wafer W during the carrying operation.
Furthermore, there may be a risk that the wafer W sticks to the arm body 13 due to the surface tension of the liquid 18, resulting in jumping of the wafer W from the arm body 13 upon transferring the wafer W toward the processing block, thereby causing a carrying error.
In addition, once the carrying operation of the wafer W in the developing apparatus is stopped, the liquid 18 accumulated at the corner may tend to be dried and produce particles 10 as shown in FIG. 15(a). These particles 10 may be produced by absorption of constituents in the air into the liquid 18 or by elution of components constituting the arm body 13 into the liquid 18 which is pure water. However, the principle of occurrence of such particles is now under investigation. Thereafter, when the carrying operation of the wafer W is restarted by the arm body 13, either by impact occurring when the arm body 13 receives a next wafer W from the exposure apparatus, or by vibration of the arm body 13 carrying a next wafer after having received it, the particles 10 may also tend to scatter into the air as shown in FIG. 15(b) and be transferred to the next wafer W. It should be noted that though a substrate holding means provided in a coating and developing apparatus is described in Patent Document 1, a countermeasure for addressing the aforementioned problem which may occur upon the introduction of the dipping exposure process is not covered therein.
Cited Patent Document:
Patent Document 1: TOKUKAIHEI No. 11-243133 | {
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Sputtering is a physical vapor deposition (PVD) process in which high-energy ions impact and erode a solid target and deposit the target material on the surface of a substrate such as a semiconductor substrate, a specific example being a silicon wafer. In semiconductor fabrication, the sputtering process is usually accomplished within a semiconductor fabrication chamber also known as a PVD process chamber or a sputtering chamber.
A sputtering chamber is used to sputter deposit material onto a substrate to manufacture electronic circuits, such as for example, integrated circuit chips and displays. Typically, the sputtering chamber comprises an enclosure wall that encloses a process zone into which a process gas is introduced, a gas energizer to energize the process gas, and an exhaust port to exhaust and control the pressure of the process gas in the chamber. The chamber is used to sputter deposit a material from a sputtering target onto the substrate, such as a metal, for example, aluminum, copper, tungsten or tantalum; or a metal compound such as tantalum nitride, tungsten nitride or titanium nitride. In the sputtering processes, the sputtering target is bombarded by energetic ions, such as a plasma, causing material to be knocked off the target and deposited as a film on the substrate.
A typical semiconductor fabrication chamber has a target assembly including disc-shaped target of solid metal or other material supported by a backing plate that holds the target. To promote uniform deposition, the PVD chamber may have an annular concentric metallic ring, which is often called a shield, circumferentially surrounding the disc-shaped target. The gap between the inner surface of the shield and the circumferential surface of the target is typically referred to as the darkspace gap.
FIGS. 1 and 2 illustrate prior art arrangements of a target assemblies used within a PVD chamber. FIG. 1 is a schematic, cross-sectional illustration of a prior art a semiconductor fabrication chamber 100 comprising a chamber body 102 and a substrate 104 supported by a substrate support 106 within the chamber body 102. A target assembly 111 includes a target 112 supported by a backing plate 114. The target includes a front face or sputterable area 120 of disposed in a spaced relationship with respect to the substrate support 106. A shield 108 comprising a generally annular shaped metal ring extends circumferentially around the target. The shield 108 is held in place in the chamber by a shield support 110. The front face 120 of the target 112 is substantially flat.
FIG. 2 shows another configuration of a prior art target assembly 211 including a backing plate 214 and a target 212 joined to the backing plate. The target 212 is in the form of a frustum, and is generally convex in shape having two inwardly beveled edges 213 such that the outer peripheral portion of the target has a thickness less than the central region of the target.
In recent development of semiconductor industry, especially in high dielectric constant and metal gate applications, there is a stringent requirement of good uniformity for thin films on the order of 1 to 5 Angstroms, which poses a challenge to the traditional physical vapor deposition (PVD). In magnetron sputtering with longer spacing from target surface to the wafer, the film at wafer central region tends to be much thicker than the other locations on the wafer, which prevents film thickness uniformity from being achieved. There is a desire to provide thin film sputtering systems that are capable of providing better uniformity in film thickness across the entire radius of substrates. | {
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The present invention relates to a foamed resin adhesive and its use for glueing wood based panels such as plywood.
With respect to glueing wood based panels and boards, quality and environmental requirements have clearly increased recently. The main purpose has been the reduction of the inevitable emissions in the working environment due to the application of the adhesive, for instance with the conventional spraying technique. On the other hand, there is a need to decrease the amount of the adhesive used for economic and ecologic reasons. Further, if the production of such wood based panels is fluctuating the premature setting of the adhesive can occasionally cause problems.
In comparison to traditional alternative spreading methods, uniform and adequate glueing results are obtained with present methods using less foamed phenolic resin adhesives. The foaming of the phenolic resins helps to reduce the contamination of the surroundings of the production lines. The foam also binds possible emissions and odours better than common methods. The foaming of the resin to increase its volume reduces the need of water and thus failures of the glue line due to excessive moisture are avoided during hot pressing. Foamed phenolic resin adhesive can be spread extremely evenly on the surface to be glued that may even be rough and irregular. The adhesive penetrates less into the materials being glued and it sets more slowly. In most common methods using foamed phenolic resin as an adhesive the foaming and the simultaneous stabilizing of the foam is accomplished with dried and powdered animal blood from slaughterhouses. The blood protein in combination with a surface active agent foams the adhesive quickly and stabilizes the foamed adhesive to a useful form for a time period required.
The U.S. Pat. No. 3,905,921 describes a rapidly foaming and setting phenolic resin adhesive especially for glueing plywood panels. A basic 30-45% resin solution containing as a resin a condensation product of a phenol and an aldehyde, especially of a phenol and formaldehyde is mixed with 5-30% dried powdered animal blood, water. and a suitable amount of glyoxal or other aldehyde to control the viscosity of the adhesive. This blood was collected from the floors of slaughterhouses, then dried, and powdered. However, such an animal blood from slaughterhouses can be a potential source of causative agents of sicknesses that can be transmitted from this blood to humans. Accordingly, the use of such an animal blood can be questionnable for health and ecologic reasons. Moreover, the quality of this blood varies causing uncontrolled changes in the properties of the adhesive.
The U.S. Pat. No. 4,403,013 relates to a foamable thermosetting adhesive for the production of plywood. This adhesive comprises a phenolic resin such as a phenol-formaldehyde resin mixed with a fatty acid amide or tertiary amine oxide as a surface active agent necessary for foaming. The foam is stabilized with clay, for instance attabulgit, which is mainly a crystalline hydrated magnesium aluminium silicate. The adhesive comprises further a thickener, such as flour from wheat, rye, potato, or natural rubber etc. A basic compound such as sodium carbonate is also added to the adhesive to adjust its pH above 9. The components of the adhesive are brought together and mixed, then air, nitrogen or any other gas inert to the mixture is fed into it with vigorous agitation to foam the adhesive.
A convenient extrusion equipment for foaming the adhesive and spreading it on wooden boards is disclosed in the U.S. Pat. No. 4,470,789. In this equipment a liquid adhesive mixture is fed via a pump through a separate line to a foaming unit for mixing a gas, typically air, to it. The obtained foam is fed through a spreading head onto the surfaces being glued.
The foamed adhesive could also be applied on wood based boards according to the process described in the U.S. Pat. No. 4,115,178, further comprising the steps of mechanical prepressing and the actual hot pressing.
The U.S. Pat. No. 4,258,088 discloses a process for producing plywood panels. In this intermittent process a foamed plywood adhesive is applied uniformly on moving surfaces being glued.
The object of the present invention is to provide a foamable resin adhesive for glueing wood based boards such as plywood panels without any animal products to foam and stabilize the adhesive. Another object of the invension is to provide a foamable adhesive that can be foamed easily and quickly, the stability, density, viscosity and other properties of the foamed adhesive being suitable for glueing especially of wood based panels and boards such as plywood, chipboard, hardboard, oriented strand board, and wafer board.
The characteristic features of the foamable resin adhesive and its use to glue wooden boards according to the present invention are presented in the appended claims.
The resin adhesive of the present invention comprises a thermosetting resin such as phenol-formaldehyde, resorcinol-formaldehyde, urea-formaldehyde, or melamine-formaldehyde resin, or mixtures or combinations thereof, an organic filling material or materials, a cationic acrylamide copolymer, a surface active agent, water, and a base. The components are mixed together in a conventional manner, for instance according to the U.S. Pat. No. 4,403,013. The proportion of the resin that is preferably added as an aqueous phenol-formaldehyde resin solution is in the range of 40-80%, preferably 50-75%. The dry matter content of this phenol-formaldehyde resin is between 35 and 65%, preferably between 40 and 50%, and the molar ratio of formaldehyde to phenol varies between 1.8 and 2.8. The resin was produced by using inorganic alkaline catalysts with hydroxyl correlation of 3-10%. Preferable inorganic alkaline catalysts include alkaline and alkaline earth metal hydroxides, oxides and salts of weak acids. The filling material such as wheat, rye or potato flour, starch, natural rubber, wood flour, cellulose derivatives or alginates is added in an amount of 2-10%, preferably 5-8%. The proportion of the cationic acrylamide copolymer is between 1 and 10%, preferably 2 to 5%, this copolymer being typically added as a 10-50% aqueous solution with a cationic ratio of 20-100%, preferably 30-80%, a molecular weight of 10,000-300,000, preferably more than 50,000, and with a pH-value between 2 and 4. Further, it is preferable to add to the adhesive an anionic or neutral surface active agent such as sodium alkyl sulfate. sulfonized alcohol ethoxylate, alfa-olefin sulfonate, or alkyl benzene sulfonate. The cationic acrylamide copolymer can be produced from monomers comprising acrylamide or monomers in a copolymeric cationic form such as a quaternary alkyl-N-alkylamine of acrylamide, a secondary or tertiary alkyl-N-alkylamine of acrylamide or a primary acrylamine, an ester of an acrylic acid, the alcohol moiety of which being a quaternary N-alkylamine alkoxide, or a secondary or tertiary N-alkylamine alkoxide or a primary aminealkoxide. The most preferable surface active agent is sodium (2-ethylhexyl)sulfate to be added in the proportion of 0.05-1%, preferably 0.1-0.5%. Moreover, a base like sodium hydroxide, sodium carbonate or any other basic compound with which the pH of the mixture can be adjusted above 9, and 5-50% water can be added to this adhesive mixture. The foaming of the mixture is preferably accomplished using high shear, for instance with known foaming devices, by introducing into this mixture a gas inert to it, such as nitrogen or air, preferably air. | {
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What is meant by “tape” 1, depicted in FIG. 1, is a segment of composite material comprising fibres, or of woven material, of elongate shape extending in a longitudinal direction dLong with a thin cross section Sec that is symmetric with respect to the longitudinal direction dLong, the thickness of the cross section Sec typically being negligible by comparison with the width and length of the tape 1.
In this particular instance, the tape 1 extends in the longitudinal direction dLong and has a plane of symmetry Psym in the said longitudinal direction dLong. It comprises a composite material of which the matrix comprises a resin in which fibres extend.
A document of the prior art, EP0891248, proposes an extendable element that can be configured into a coiled first state in which the element is coiled substantially parallel to a first axis, and into an extended second state in which the element extends substantially parallel to a second axis. The extendable element is made up of a substrate and of at least one fibrous layer of which the fibres are crossed. Each of the fibres is oriented at an angle of between 0 degrees and 90 degrees with respect to the first axis such that when the element is extended in a direction substantially parallel to the second axis, said crossed fibres cause contraction in a direction oriented at a certain angle to the second axis, so as to place the element in the second state.
Let it be noted that all the angular offsets mentioned in the remainder of this application are oriented in the clockwise or negative trigonometric direction.
Moreover, it is also known practice to create tapes 1 by superposing layers comprising a first fibrous material, according to the principle depicted in FIGS. 2a and 2b.
More specifically, FIG. 2a relates to a tape comprising a stack Emp or superposition of four fibrous layers. The direction of orientation of the fibres of one of the layers Cn form an angular offset α with respect to the longitudinal direction dLong, the angular offset α being between 0° and 90°. The fibres of the other layer Cn+1 make an angular offset (π−α) with the longitudinal direction dLong. In other words, the entirety of one layer comprises at least one first group of fibres of which the direction makes a first angular offset α with the longitudinal direction dLong and the entirety of the next layer comprises the first group of fibres of which the direction forms an angular offset (π−α) with respect to the longitudinal direction dLong.
FIG. 2b is a depiction of the stack Emp of FIG. 2a; it is made up of four fibrous layers Cn of which the direction of the fibres forms an angular offset with respect to the longitudinal direction dLong, the value of the angular offset alternating between (+α) and (π−α) between the layer Cn and the next layer Cn+1.
This type of antisymmetric tape avoids coupling between bending and torsion but on the other hand is sensitive to temperature variations, as FIGS. 3a and 3b demonstrate.
FIG. 3a schematically depicts a tape 1 comprising two layers of fibrous composite materials of which the fibres of the first layer C1 are oriented in a first direction d1 and the fibres of the second layer C2 are oriented in a second direction d2. Under the effect of an increase in temperature in particular, the layers of composite material C1, C2 each expand in a direction transverse to the direction of the fibres, since the fibres have a very low expansion coefficient, of the order of a few 10−6K−1, such that twisting of the tape 1 is observed.
FIG. 3b clearly shows the torsion that arises when the tape 1 is subjected to variations in temperature. Specifically, the tape 1 (on the left) which extends in the longitudinal direction dLong has a cross section Sec of which the value of the radius of curvature rs in a transverse direction dTransv perpendicular to the longitudinal direction dLong is substantially constant over the entire cross section Sec; in other words, the tape 1 has a shape that is uniformly substantially concave. Following an increase in temperature, a greater turning-up of two of the diagonally opposite vertices of the tape 1 may be observed, notably in the right-hand figure.
It will therefore be readily appreciated that a tape 1 that twists in the event of variations in temperature will not be able to be wound and/or unwound cylindrically.
FIGS. 4a-4d depict a process for the deployment of a conventional tape as it passes from a fully wound state in FIG. 4a to a fully unwound state in FIG. 4d, the unwinding process being said to be chaotic. FIGS. 4b and 4c illustrate intermediate states exhibiting several wound zones and/or several unwound zones. The unwinding process is jerky and uneven.
Contrary to the chaotic unwinding process, a process for the unwinding of a tape 1 between a wound first state and an unwound second state is qualified as “smooth” when all of the intermediate states between the first and the second state comprise a single continuous portion of wound tape of which the value of the radius of curvature is higher than a threshold value and a single continuous portion of unwound tape of which the value of the radius of curvature is less than the threshold value and is continuous over the unwound portion. In other words, the unwinding process occurs uniformly with no zone in which the tape 1 is kinked. During the unwinding process, the length of the continuous wound portion of tape decreases over time and that of the continuous unwound portion increases over time. | {
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Parking meters can be used as a revenue stream as well as for the management and flow of vehicles and traffic in a municipality. However, in order to increase that revenue stream, the parking meters must be managed efficiently. Various parking meters have been developed for improving the efficiencies of parking meters. This has resulted in parking meters storing information relating to the operation of the parking meter, such as fees collected, errors, coin jams, etc. This parking meter information is then collected and analyzed to improve the revenue stream. This may include adding additional parking meters to high use areas, increase the cost of parking in high use areas, etc.
Parking meters may be classified broadly as multi-space parking meters, or single space parking meters. Multi-space parking meters are larger units in which a parking ticket can be purchased and then must be displayed on the vehicle, or the user may enter a parking space number corresponding to a parking spot for which parking is being purchased and pays for their parking. Multi-space meters are typically used to provide parking metering to a group of parking spaces, a portion of or all of a street block, or to a portion of or all of a parking lot. The multi-space units are generally large in size and typically are powered either by a connection to the power grid, or by a battery in combination with a solar panel. This allows the multi-space meters to power peripheral devices, such as cellular radios for communicating parking meter information to a monitoring location.
In single space parking meters, which are a common aspect of the fixed infrastructure in many cities and municipalities, the parking meters may not normally have radios, but they do capture and generate quantities of data which would be beneficial for managers attempting to manage the parking meters or increase the revenue stream generated from the parking meters. Unfortunately, capturing this data from the street is manually labor intensive. To do so a data collector such as a collections officer is typically given a hand-held device such as a portable data terminal (PDT) and sent out to each parking meter which is probed in turn and the data is captured. Each parking meter may take between 10 seconds and 30 seconds to complete the data capture cycle. The probing is typically carried out either via infrared communication between the parking meter and the hand-held device at an approximate distance of 6 inches, or via a physical blade probe that is inserted into the coin slot of the parking meter. Once the parking meter information is downloaded onto the hand-held device, it is returned from the field, and the parking meter data is uploaded to a computer system and the manager can then view and report on the parking meter data. It may be necessary to repeat this data collection cycle each week or so in order for the parking meter system to be effectively managed. Some managers may have the parking meter data collected concurrent with the physical coin collection; however, this can make the coin collections much more time consuming and tedious for the collections officer. In some instances, the collections officer collecting the coins and the data concurrently will either forget to collect the data, or forget to collect the coins. Where a collections officer is sent to collect the parking meter data separately from a collections officer collecting the coins, the collected information may not be as useful. From an auditing/reconciliation standpoint the data is not as useful, as it is more difficult to analyze or reconcile the collected parking meter data in relation to the coins collected when the data and coins are not collected coincidently.
Some single space parking meters may wirelessly communicate parking meter information to a monitoring location using cellular radios. A drawback of using cellular radios in a single space parking meter is the power consumption. Available power in a single space parking meter is considerably less than in a larger multi-space parking meter, which may be connected to the power grid. Also, data communications over a cellular network can become expensive where there are large numbers of parking meters involved, as each parking meter will need a cellular radio and a corresponding account activated under a telecommunication services provider. Also, most commercial data plans are scaled up in price relative to the amount of data that is transmitted and can become expensive when relatively large amounts of data are to be communicated. Additionally, the minimum data plans offered by telecommunication service providers may be excessive relative to the data transmission requirements for some sites.
Other single space parking meters communicate parking meter information wirelessly to a proximal wireless fixed access point, such as a wireless router, located up to several hundred feet away, or one or two city street blocks away. These single space parking meters may use various communication technologies. In addition to cellular radio technology there are also a variety of alternative, low power, low cost wireless radio frequency (RF) based technologies that can be deployed and used in the parking meter and remote access point equipment that can achieve the required transmission distances. Unlike the cellular radios, many of these wireless RF technologies, such as Wi-Fi (802.11), Zigbee radios that adhere to IEEE 802.15.4 wireless standards, as well as many other proprietary license free radio systems, do not require individual radio registration and licensing nor require payment of “airtime” fees. The wireless fixed access point communicates wirelessly with the single space parking meters, and may communicate with a monitoring location and/or the Internet either via cellular radio/modem, or via hard wire connection such as a cable modem. However, some wireless communications, or line of sight technologies, between the single space parking meters and the fixed access point may suffer from less than ideal reliability or power consumption, especially when transmitting over longer distances such as those required for communicating with a fixed access point, as obstacles such as large vehicles and surrounding infrastructure may sometimes block or impede communications paths.
There is therefore a need for an improved data collection system for electronic parking meters, which addresses or mitigates one or more of the defects described above. | {
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Dimension reduction is the major consideration for designing an optical imaging lens in recent years. When reducing the length of the optical imaging lens, however, achieving good optical characteristics becomes a challenging problem.
U.S. Pat. No. 7,502,181, U.S. Pat. No. 7,826,151 and U.S. Pat. No. 8,422,145 all disclosed an optical imaging lens constructed with an optical imaging lens having five lens elements. In these patents, the aperture stop is positioned before the first lens element, and the transition of refracting power of the first two lens elements is positive-negative. However, such configurations still fail to satisfy users needs for a better imaging quality and thinner and slimmer design, because the HFOV (half of field of view) in these patents is merely 32˜33 degrees and the lengths of the optical imaging lenses thereof fall into the range of 6.5˜8.0 mm.
Therefore, there is needed to develop optical imaging lens with a shorter length, while also having good optical characters. | {
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1. Field of the Invention
The present invention relates to a method of recording information on a recording medium and erasing the recorded information.
2. Description of Related Art
There is known an information recording and reproducing apparatus capable of recording information on an optical disc, such as a DVD-R/RW and the like, and capable of reproducing and erasing the recorded information. So far, additional recording was performed by a method, such as a UDF (Universal Disk Format) and a multi-session, as for an additionaly-recordable-type recording medium capable of recording information only once, like a DVD-R. In the method, when the recorded information is erased, newest file management information is wholly utilized by additionally recording changed file management information in a new area while a last file management information area is left as it is (see Japanese Patent Application Laid-open under No. 2002-324383).
Namely, a data area is left as it is without any change, and data of the file is not erased from the disc until the data area is overwritten by other files. It takes a long time to completely erase all the contents of the file in the data area, which is not efficient. Therefore, such the method is adopted.
However, in the above-mentioned method of additionally recording the data, the old recorded data remains on the disc, and the information in the last file management information area can be also read. Therefore, even after an erasing command is executed, the recording data which is apparently erased can be actually readout from the information recording medium by reading the information in the old file management information area before the erasure. In addition, even if such file management information before the erasure is deleted, the recording data itself remains on the disc. Therefore, it is possible to restore the recorded data by tracing the portion thereof. Like this, in the conventional erasing method, it is impossible to erase the recorded data in a manner completely unreadable. Thus, there occurs probability that the recorded data which was apparently erased, such as important data including personal information and the like, is restored and watched by the above-mentioned method.
As a method of completely erasing the data which is recorded on the recording medium capable of recording the information only once, there are known a method of destroying the recording medium itself, and a method of making it impossible to read out all the file management information are a by physically overwriting it. However, in those methods, the data other than the data to be erased cannot be read out, either. Further, when the method of overwriting all the file management information area is utilized, it problematically takes a long time for the process. | {
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The present invention relates generally to data processing systems and more particularly to a priority determining system for a common bus.
A central processor is typically coupled by a common bus to a plurality of peripheral devices each of which requires access to the central processor on some priority basis. Priority determination is required for the case where two or more peripheral devices attempt to obtain control of the common bus at once. A number of prior art priority determination systems exist. One such system is described in an article entitled, "Unified Bus Maximizes Minicomputer Flexibility," by D. Chertkow et al., ELECTRONICS, Dec 21, 1970, pages 47-52. Generally the major advantage of a common or unified electrical bus is in the ability to utilize more advanced memories and peripheral equipment as the hardware becomes available. This is possible because all the devices used with a common bus send and receive address, data, and control information, by the same set of signals.
In U.S. Pat. No. 3,766,530, entitled "Communications Between Central Unit And Peripheral Units," by R. Atsushi Ito, there is disclosed a priority determining system wherein an interrogation signal is initially sent to all the peripheral devices. In response to the interrogation signal, those peripheral devices requesting service are placed in a waiting queue and are then serviced in sequence. After the servicing is completed for all devices in the queue, the following interrogation signal causes another waiting queue to be established.
It would be highly advantageous to have a priority determining system that allows the highest priority devices to have access to the common bus without the time delay encountered by having to first allow access to all the peripheral devices that make up one queue.
The present invention utilizes the advantages of the common bus without the need for establishing a waiting queue.
In U.S. Pat. No. 3,629,854, entitled, "Modular Multiprocessor System with Recirculating Priority," by E. A. Hauch et al., there is disclosed another type of priority system which operates with a common bus. The system operates by allowing each processor to scan all peripheral devices when the processor receives a priority bit. The priority bit is circulated in a closed loop, which links each of the processors. Only the processor having possession of the circulating bit is allowed access to the common bus. | {
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This disclosure relates to a system and method for controlling the speed of an electric motor, and more particularly to a system and method for controlling the speed of a voice coil motor that moves the head of a disk drive.
In the event of a disk drive power failure, it is typical to use reserve power to retract the read/write head to prevent it from striking and damaging the platter surface. This function is known as “emergency retract” and can be performed as “blind retract” or “velocity-controlled retract.” Velocity-controlled retract is preferable, because controlling the speed at which the voice coil motor (VCM) retracts the head prevents or at least minimizes damage to the head as a result of hitting the ramp stop too hard (if it is retracted too quickly). At the same time, the available power for performing the retract operation is limited, so a trade-off between velocity regulation and power consumption has to be made.
One known method for controlling the speed of the VCM uses pulse width modulation (PWM), applying power to the VCM in pulses to conserve power. The speed of the motor is controlled by the width or duration of the pulses. The speed may be determined by detecting the back-electromotive force (back-EMF, or BEMF) generated when current passes through the motor. Comparison of the actual speed, as represented by the actual BEMF, to a target speed, as represented by a target BEMF, can be used to control the pulse width. The BEMF profile may be divided into regions using an analog-to-digital converter (ADC), and decoded to the pulse width of the subsequent PWM drive.
In order to improve VCM speed control, it is desirable to increase the number of regions into which the BEMF profile is divided to provide finer adjustment of the pulse width. However, using a higher-resolution ADC during an emergency retract consumes more power at a time when power is at a premium. In addition, it may be desirable to make the pulse width programmable to accommodate different models of disk drive, or even differences among drives of the same model. | {
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} |
1. Field of the Invention
This invention relates generally to optical telecommunication systems and, more particularly, to receivers employed in such systems.
2. Description of the Related Art
Polarization diverse optical circuits use a polarization beam splitter (PBS) to split an incoming optical signal into two orthogonal and spatially separated polarization states. These output polarization states are often the transverse electric (TE) and transverse magnetic (TM) polarization states of a planar optical waveguide circuit.
A PBS in planar lightwave circuits (PLCs) may be formed from a birefringent interferometric structure, such as the birefringent Mach-Zehnder PBS described in U.S. Pat. Nos. 7,035,491 and 7,356,206, both of which are incorporated herein by reference in their entirety. As depicted in FIG. 1, the basic configuration of an interferometric PBS includes an input coupler 114 having an input and two outputs and an output coupler 120 having two inputs and two outputs, and a pair of birefringent interferometric arms 116, 118 between the input and output couplers. The first arm 116 may couple the first output port of the input coupler 114 to the first input port of the output coupler 120, and the second arm 118 may couple the second output port of the input coupler 114 to the second input port of the output coupler 120. As depicted, the first arm 116 has a length L1 which differs from a length L2 of a second arm 118. The arms 116, 118 are “birefringent” with respect to each other such that the differential phase accumulation of two orthogonal polarization states propagating in the arms 116, 118 is correspondingly different. The differential phase accumulation, is typically the difference in phase between light having TE and TM polarizations propagating over length L1 in arm 116 and over length L2 in arm 118.
In operation, an optical signal may be provided as an input 112A to the input coupler 114. The coupler 114 splits the optical signal into a first optical signal which propagates on arm 116 and a second optical signal which propagates on arm 118, the first and second optical signals being of substantially the same optical power. In Mach-Zehnder interferometers, the amount of power exiting each of the first and second output ports of the output coupler 120, labeled “Output 1” and “Output 2” for example, may depend on the relative, or differential, phase between each of the two optical signals propagating in the arms 116, 118 at the corresponding input ports of the output coupler 120. In the special case that the differential phase is observed to be in multiples of 0°, for example 0°, 360°, etc., or mathematically 0°+N*360°, for any integer number N equal to or greater than 0, all the optical power will be directed out the first of the two output ports of the output coupler 120, and none out the second port. In the special case that the differential phase is observed to be in multiples of 180°, for example 180°, 540°, etc., or mathematically 180°+N*360°, for any integer number N equal to or greater than 0, all the optical power will be directed out the second port, and none out the first port.
The birefringent Mach-Zehnder PBS is typically designed such that for one polarization, the differential phase between first and second optical signals propagating through arm 116 and arm 118, respectively, is a multiple of 0°, while for the other orthogonal polarization the differential phase is a multiple of 180°. As a result, the optical signal associated with the first polarization will exit entirely at the first of the two output ports, Output 1 for example, of the output coupler 120, as an output signal 122A for example, while the optical signal associated with the other orthogonal polarization will exit entirely at the second of the two output ports, Output 2 for example, of the output coupler 120, as an output signal 122B for example.
Fabrication deviations and/or material ageing effects may impact the performance of the PBS over time, for example, resulting in the birefringent interferometric arms 116, 118 having differential phase lengths differing from the ideal lengths corresponding to relative phase multiples of 0° and 180°, as discussed above. With this degradation of the PBS performance, the two outputs of the output coupler 120 no longer include a single polarization state. Rather, a component of each polarization is present in the output signals 122A, 122B of the output coupler 120. Deviations away from the ideal design can be compensated by tuning one or both of the interferometric arms 116, 118, as discussed in commonly owned U.S. Pat. Nos. 7,035,491 and 7,356,206, both incorporated herein by reference in their entirety.
A thermo-optic effect is an often used tuning mechanism in optical devices. For instance, thermal energy in the form of heat may be applied to one of the interferometric arms 116, 118 to change the phase relationship of the propagating optical signals. This approach can be used to tune the phase of each of the optical signals propagating in the arms 116, 118 so that they are closer to the design criteria, e.g. multiples of 0° and 180° for the two polarizations, respectively, as described above. An electro-optic effect, for example where an electrical current or voltage changes the optical material index, may similarly be used for tuning Often, however, characteristics of the PBS may change over time, due to fabrication defects, device ageing or environmental conditions such as temperature or humidity for example, leading to performance degradation in the PBS.
What is needed is a PBS which can be tuned over a period of time commensurate with the use of the PBS to compensate for fabrication defects, device aging, or environmental operating conditions, which may lead to a corresponding performance degradation of the PBS. | {
"pile_set_name": "USPTO Backgrounds"
} |
(1) Field of the Invention
The present invention relates to a rotorcraft tail rotor. The term rotorcraft is used in this application to describe any type of rotary wing aircraft, such as in particular helicopters.
(2) Description of Related Art
In current usage, such a tail rotor is also called an “anti-torque” rotor since it makes it possible to exert a torque for opposing the rotary movement in yaw produced by a main rotor, which provides the rotorcraft with lift and propulsion.
Thus, the tail rotor of a rotorcraft generally has a substantially horizontal axis of rotation and it may either be integrated in the fuselage of the rotorcraft, or else it may be external thereto. When the rotor is integrated in the fuselage, it is then referred to by the terms ducted tail rotor or Fenestron®.
In addition, the tail rotor may comprise at least two blades arranged symmetrically about the axis of rotation of the rotor. Each blade is movable in pivoting about an axis referred to as the “pitch” axis in order to vary the angle of incidence of the blades relative to the surrounding air and thus vary the thrust of the rotor. Such variation can in particular be carried out when the pilot of the aircraft wishes to modify the yaw angle described by the aircraft, or more simply to increase the power of the main rotor, with a consequent need to increase the value of the yaw torque.
Furthermore, in order to vary the pitch angle, the pilot actuates pedals of a rudder bar making it possible to actuate the rod of a tail rotor servo-control that is hydraulically connected to a control plate. Such a control plate can be moved in translation in a direction parallel to the axis of rotation of the rotor. Moving the pedals, from one abutment to another, varies the pitch of the blades of the antitorque rotor, by means of each rod connecting said plate to each blade, through an angle that may for example lie in the range −8° and +23° about a flat position of 0°.
In flight, as soon as the thrust of the rotor is no longer zero, i.e. when the pitch angle is different from 0°, torque for returning the blades to a flat position is exerted on the blades and tends to return the pitch angle to 0°. When a rotor is in rotation, the centrifugal forces acting on each blade element cause any pitch variation to be opposed, and the blades to be returned to the plane of rotation. In order to calculate the resulting torque M being exerted on the blades, reference may be made to the known literature on the subject, and for example, consideration may be given to a mass element dm of the blade, situated at a distance r′ from the center of the rotor. Then, the centrifugal force element acting on that mass element has the value:dF=Ω2·r′·dm where Ω is the angular velocity of the rotor.
This force element can then be resolved into a component dFZ parallel to the pitch axis and a component dF1 perpendicular to the pitch axis. The component dF1 then has the value:dF1=dF·sin φ=Ω2·r′ sin φ·dm=Ω2·x·dm where x is the distance of the blade element under consideration from the pitch axis.
The component dF1 is then situated at a distance y from the plane for which the general pitch angle θ is zero, thus giving rise to a torque element dM tending to return the blade to a flat position, i.e. in a plane xOz.
However, if it is accepted that the center of gravity G of the section of the blade is situated on the pitch axis, the value of that torque element is given by the expression:dM=Ω2·x·y·dm and the resulting torque M is written:
M = Ω 2 · ∫ - C 1 C 2 x · y · ⅆ m with C1 and C2 corresponding respectively to the orthogonal projections onto an axis Ox of a leading edge of the blade section at the point G and of a trailing edge of blade section at the point G.
With hydraulic power assistance, and more particularly by means of the servo-control, the “return-to-flat” effect of the rotor can be countered so as to eliminate the reversibility of the command. However, in the event of failure of such hydraulic assistance, as may for example result from a leak in the hydraulic system or from a failure of a hydraulic pump, the force necessary to operate the pedals suddenly becomes very considerable.
For that reason, an additional hydraulic safety device, referred to as a yaw “force compensator” is installed, along with the servo-control, which makes it possible to offload the major portion of the aerodynamic force feedback generated by the tail rotor. Such a force compensator makes it possible to generate a force opposing the return-to-flat force being exerted on the blades. The force compensator thus comprises a hydraulic pressure accumulator that is independent from the main hydraulic assistance system and a control lever for multiplying the movement stroke of a piston of an actuator that is connected hydraulically to the pressure accumulator in order to create a “spring having a negative slope”.
However, such a force compensator also incorporates numerous hydraulic members that can also be subjected to damage. A leakage in the force compensator would then prevent production of the force necessary for opposing the return-to-flat force.
That could therefore result in blocking of the system for controlling pitch variation of the tail rotor. Specifically, in the event of simultaneous malfunctions of the hydraulic assistance and of the force compensator, the forces required to enable the pilot to modify the pitch of the blades of the tail rotor are then too great and they prevent the pilot from varying the pitch of the blades of the tail rotor by using the pedals.
Thus, a first object of the invention is to limit possible causes of control over the pitch angle of a tail rotor becoming blocked, and thus to improve rotorcraft safety.
In addition, with increasingly powerful aircraft engines, it has become necessary to increase the surface area of the blades of the tail rotor, e.g. by adding “tabs” to the trailing edge of each blade. This consists in adding elements to the trailing edge, which elements extend a few centimeters in the chord direction and occupy a longitudinal fraction of the span. This increase in the surface area of the blades thus generates a considerable increase in the static and dynamic force transmitted by the blades to a rotor head.
In order to reduce these forces, the root of each blade is fitted with two compensation weights emerging symmetrically substantially perpendicularly to a main inertia axis of each blade, or more simply to the longitudinal mid-plane defined by each blade. Those compensation weights serve to create a moment opposing the return-to-flat moment of the blades and thus to reduce the forces required to control the pitch angle. Each blade element is thus stabilized, regardless of the pitch angle of the rotor.
Such compensation weights are more generally referred to as “Chinese weights”. They thus co-operate with each blade to form a rigid single-piece unit, and in particular they are described by the Applicant in document FR 2 719 554. Indeed, that document describes the compensation weights as being stationary elements forming projections on both sides of a longitudinal mid-plane of the blade.
However, although such Chinese weights make it possible to limit static force, they do not make it possible to reduce the dynamic force transmitted by the blades to a rotor head. Such constraints may then lead to reducing the lifetime of the revolute joint between each blade and a hub body. Such a revolute joint is indeed formed by elements constituting the pitch hinge, formed by laminated bearings. Those bearings are constituted by a combination of metal and elastomer, and they are generally cylindrical or even conical in shape. Furthermore, they are the site of considerable mechanical stress during rotation of the tail rotor, and more particularly during stages of varying the pitch angle.
That thus results in maintenance intervals for the aircraft being shortened, in particular concerning replacement of the wear members that take up these forces. However, shortening maintenance intervals increases the cost of operating those aircraft, and commercially that is to be avoided.
In addition to Chinese weights that are stationary relative to the roots of the blades of a tail rotor, it is also known to fit a main rotor of a rotorcraft with oscillating pendulums or weights that are movable in pivoting relative to the blade roots. Such arrangements are described in particular in documents FR 2 530 216, FR 2 435 391, and FR 2 959 484 but they do not make it possible to guarantee good reduction of the static and dynamic force generated by the rotation of a tail rotor.
Indeed, the projection described in document FR 2 530 216 is formed by the casing of the shaft 6 and is thus hollow. Such a casing thus does not act as a Chinese weight in the same way as a solid projection. Furthermore, the direction of the revolute joint between the pendulum and the casing is perpendicular to the direction in which the casing emerges relative to the main inertia axis of the blade element. Such an arrangement is therefore not suitable for reducing the static and dynamic force generated by the rotation of a tail rotor.
Document FR 2 435 391 describes a main rotor of a rotorcraft provided with weights oscillating relative to a blade element. However, strictly speaking, there is no projection emerging perpendicularly to a main inertia axis of a blade element. The oscillating weights are thus directly positioned on either side of the blade element, without being spaced apart from a main inertia axis. Such an arrangement is therefore not suitable for reducing the static and dynamic forces generated by the rotation of a tail rotor in simple and optimum manner.
Document EP 0 058 117 describes a suspension for a main gearbox of a helicopter with oscillating weights connected to the fuselage by deformable portions, but it is not transposable to a rotorcraft tail rotor for the purpose of reducing the static and dynamic forces generated by the tail rotor rotating.
Furthermore, in another alternative for limiting stress in the laminated bearings, it is also possible to limit engine power, and thus aircraft speed, which is also prejudicial from a commercial point of view. However, such a solution is merely palliative and does not under any circumstances enable the problem to be resolved at its source.
A second object of the present invention is thus to provide a rotor that enables the above-mentioned limitations to be overcome, and in particular that significantly reduces the static and dynamic forces generated by the tail rotor rotating. Thus, the structural design of the tail rotor of the invention makes it possible to limit, or even to eliminate, the mechanical stress transmitted to the laminated bearings, to the pitch control rods, and to the entire drive linkage, and does so while using the engine(s) at maximum power.
In addition, as described in document EP 0 773 881, tail rotors are also known in which a gyroscopic mechanism makes it possible to vary thrust automatically. It is thus possible to stabilize the yaw torque of the helicopter in flight.
However, such a solution is mechanically complex to implement and thus generates considerable manufacturing and/or adaptation costs in comparison with current solutions involving Chinese weights, hydraulic assistance by servo-control, and/or a force compensator. | {
"pile_set_name": "USPTO Backgrounds"
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Telecommunications networks that provide wireless access (e.g. GSM, UMTS, WiMax, LTE) have developed tremendously over the past years. In such networks, voice and data services can be provided to terminals having a high mobility, i.e. the communication terminals are not bound to a particular location and are freely movable through the area covered by the network. A gateway node of the telecommunications network enables connection to a further network, for example a network based on IP such as the internet.
The availability of such a telecommunications network connected to the further network has resulted in demands for further services, including services that relate to so-called machine-to-machine (M2M) services. Machine type communication is currently being standardized in 3GPP TS 22.368. M2M applications typically involve hundreds, thousands or millions of communication modules which each act as a communication terminal to the telecommunication network. An example involves the electronic reading of e.g. ‘smart’ electricity meters at the homes of a large customer base over the telecommunications network from a server connected to the further network. A characteristic of some of the M2M applications is that the exchange of data with the server is infrequent, for example once every day or so for a smart electricity meter.
Other examples include sensors, meters, vending or coffee machines etc. that can be equipped with communication modules that allow reporting status information to a data processing centre over the telecommunications network. Such devices may also be monitored by the server. The data processing centre may e.g. store the data and/or provide a schedule for maintenance people to repair or refill a machine, meter, sensor etc.
Various information messages may need to be transmitted to the large amount of communication terminals. It may occur that information messages need to be transmitted to a considerable number of the communication terminals in a short time frame. Such information messages may result in a considerable message load for the telecommunications network. The message load may relate both to the signalling load incurred on the transmission links used for the exchange of the information messages and incurred in the involved nodes to transmit and receive the information messages and to the processing load incurred in the affected nodes to process the information contents of the information messages. Therefore, there is a need for a more efficient transmission of information messages for M2M communications. | {
"pile_set_name": "USPTO Backgrounds"
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This invention relates to a bird-deterring device and more particularly to such a device for preventing birds from nesting or roosting on an upwardly facing horizontal surface, such as a window sill, a window ledge, a roof or other projection of a building.
The prior art suggests a number of techniques for performing this general function. A patentability search on the disclosure hereof has revealed the following U.S. patents:
______________________________________ U.S. Pat. No. Issue Date Inventor ______________________________________ 2,142,371 January 3, 1939 Peles 2,485,148 October 18, 1949 Fralin 3,148,417 September 15, 1964 Bellas 3,416,266 December 17, 1968 Eron 3,436,882 April 8, 1969 Keefe 4,937,988 July 3, 1990 Gratton ______________________________________
The patents to Fralin and Bellas seem to be representative of the cited patents.
Fralin presents an antiroosting device comprising a rectangular rotatable wire frame formed of a strand of wire. The frame has a first straight side, and angled end portions and the wire ends are twisted together to form a second straight side parallel to the first side, with aligned journal loops at the angled portions. Journal brackets are provided for mounting on a building and carry aligned rods extending through the journal loops. The theory is that a bird intending to roost on the device will attempt to perch on one of the straight sides and the weight of the bird will cause the frame to rotate, distracting the bird and causing it to leave.
Bellas discloses a bird-proofing device applicable to ledges, sills and the like of buildings to protect same against birds. The Bellas device includes a plurality of taut, substantially parallel strands supported by suitable brackets and retained in a three-dimensional spacing pattern, to prevent birds such as pigeons, crows, sea gulls or the like from alighting on a ledge, sill or the like on which the device is mounted.
The prior art devices, including particularly Fralin and Bellas, are somewhat cumbersome to set up and may be quite inefficient in terms of providing coverage of a desired area, such as a projection which may be quite large.
Accordingly, it is an important object of the present invention to provide an improved bird-deterring device for preventing birds from nesting or roosting in undesirable places.
It is another object of the invention to provide such a bird-deterring device which is of simple construction and easy to set up.
It is a further object of the invention to provide such a bird-deterring device of increased efficiency in terms of providing effective coverage of a desired generally horizontal area of a building.
It is yet another object of the invention to provide such a bird-deterring device which will not harm birds in any way.
The manner in which a bird-deterring device according to the invention functions in attaining the foregoing objects and advantages will become apparent hereinafter. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to a display device and a method of controlling a display device.
2. Description of the Related Art
In recent years, ensuring reliability of a display element in a display device has become an extremely important challenge. Particularly, ensuring structural and mechanical reliability or reliability relating to display performance is still a crucial matter as has been in the past.
For example, Japanese Unexamined Patent Application Publication No. 2005-173193 discloses a technique in which a situation of an image is determined from data, such as image data, that can indicate a display state of a device and lighting of a horizontal scan line is controlled to prevent overcurrent, in order to prevent life degradation of an element due to temperature rise according to current flow amount.
Also, Japanese Unexamined Patent Application Publication No. 2007-240617 describes that a control of an optical characteristic such as refractive index is performed using a photodetector as a polarization detecting unit by quantitatively detecting a change amount of deformation due to minute stress applied to a display device as a change in polarization state of incident light. | {
"pile_set_name": "USPTO Backgrounds"
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1. The Field of the Invention
The present invention relates generally to medical devices and methods of use for treating an internal tissue structure. More particularly, the present invention relates to medical devices, systems, and methods for reducing the size of an internal tissue opening.
2. The Relevant Technology
Physical malformations or defects that are present at birth can be detrimental and even lethal when left uncorrected. A PFO is an example of a cardiac birth defect that can be problematic and even result in death when combined with other factors such as blood clots or other congenital heart defects. A PFO occurs when an opening between the upper two chambers of the heart fail to close after birth.
Some of the problems associated with a PFO can occur when a blood clot travels from the right to the left atria of the heart through the PFO, and lodges in an artery that feeds blood to the brain. A blood clot in the left atrium can be passed through the aorta and travel to the brain or other organs, and cause embolization, stroke, or a heart attack. A PFO can be treated by being closed by a surgical procedure. Additionally, other similar defects (e.g., septal or otherwise) where some tissue needs to be closed in order to function properly can include the general categories of atrial-septal defects (“ASDs”), ventricular-septal defects (“VSD's”) and patent ductus arteriosus (“PDA”), and the like.
FIGS. 1A-1C depict various views of a heart having a PFO. The heart 10 is shown in a cross-section view in FIG. 1A. In a normal heart 10, the right atrium 30 receives systemic venous blood from the superior vena cava 15 and the inferior vena cava 25, and then delivers the blood via the tricuspid valve 35 to the right ventricle 60. However, in the depicted heart 10 a septal defect, which is shown as a PFO 50, is present between right atrium 30 and left atrium 40.
The PFO 50 is depicted as an open flap on the septum between the heart's right atrium 30 and left atrium 40. In a normal heart 10, the left atrium 40 receives oxygenated blood from the lungs via pulmonary artery 75, and then delivers the blood to the left ventricle 80 via the mitral valve 45. In a heart 10 having a PFO 50 some systemic venous blood can also pass from the right atrium 30 through the PFO 50 and mixes with the oxygenated blood in left atrium 40, and then is routed to the body from left ventricle 80 via aorta 85.
During fetal development of the heart 10, the interventricular septum 70 divides the right ventricle 60 and left ventricle 80. In contrast, the atrium is only partially partitioned into right and left chambers during normal fetal development, which results in a foramen ovale fluidly connecting the right and left atrial chambers. As shown in FIG. 1B, when the septum primum 52 incompletely fuses with the septum secundum 54 of the atrial wall, the result can be a tunnel 58 depicted as a PFO 50.
FIG. 1C provides a view of the crescent-shaped, overhanging configuration of the septum secundum 54 from within the right atrium 30 in a heart 10 having a PFO 50. The septum secundum 54 is defined by its inferior aspect 55, corresponding with the solid line in FIG. 1C, and its superior aspect 53 represented by the phantom line, which is its attachment location to the septum primum 52. The septum secundum 54 and septum primum 52 blend together at the ends of the septum secundum 54. The anterior end 56a and posterior end 56p are referred to herein as “merger points” for the septum secundum 54 and septum primum 52. The length of the overhang of the septum secundum 54, which is the distance between superior aspect 53 and inferior aspect 55, increases towards the center portion of the septum secundum as shown.
The tunnel 58 between the right atrium 30 and left atrium 40 is defined by portions of the septum primum 52 and septum secundum 54 between the merger points 56a and 56p which have failed to fuse. The tunnel 58 is often at the apex of the septum secundum 54 as shown. When viewed within right atrium 30, the portion of the septum secundum 54 to the left of tunnel 58, which is referred to herein as the posterior portion 57p of the septum secundum, is longer than the portion of the septum secundum 54 to the right of tunnel 58, which is referred to herein as the anterior portion 57a of the septum secundum 54. In addition to being typically longer, the posterior portion 57p also typically has a more gradual taper than the anterior portion 57a as shown. The anterior pocket 59a is the area defined by the overhang of the anterior portion 57a of the septum secundum 54 and the septum primum 52, and it extends from the anterior merger point 56a toward the tunnel 58. Similarly, the posterior pocket 59p is the area defined by the overhang of the posterior portion 57p of septum secundum 54 and the septum primum 52, and it extends from the posterior merger point 56p toward the tunnel 58.
Conventional treatments for PFO, and other related conditions have generally involved invasive surgery, which also presents a risks to a patient. Although there are some less invasive treatments for PFO, such treatments have been less efficient at closing the PFO opening than techniques involving invasive surgery. | {
"pile_set_name": "USPTO Backgrounds"
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In general, a bill processing apparatus, which is one of the embodiments of the paper sheet processing apparatus, is incorporated into a service device such as a game medium rental machine installed in a game hall, a vending machine or a ticket-vending machine installed in a public space, or the like which identifies the validity of a bill inserted from a bill insertion slot by a user and provides various types of products and services in accordance with a value of the bill having been judged as valid.
For example, Patent Reference 1 discloses a bill processing apparatus comprising a conveyance mechanism to convey a bill inserted into a bill insertion slot and reading means for reading the bill, wherein the bill processing apparatus conveys the bill identified as legitimate as a result of an authenticity judgment of the bill read by the reading means toward a housing part, and returns the bill identified as counterfeit toward the bill insertion slot. Further, this Patent Reference 1 discloses that a pull-out prevention mechanism that prevents the bill from being drawn out toward the bill insertion slot is provided in order not to allow a bill drawing-out activity after reading information of the bill by the reading means. Into such a bill processing apparatus, bills in various kinds of conditions may be inserted from a bill insertion slot by a user. For example, even a legitimate bill, which is supposed to be accepted under a normal condition, may be inserted in an improper condition that a leading end portion of the bill is in a folded state or the like (hereinafter, the improper condition in which the bill has a folded portion or the like is referred to as “a damaged condition”). When a damaged bill is inserted, the bill may be hooked or stuck during the conveyance by the conveyance mechanism such that a conveyance failure may be caused. In particular, provided that a pull-out prevention mechanism is installed in the bill traveling route, a bill may be easily stuck on the portions, which is more likely to cause a conveyance failure.
[Patent Reference 1] Japanese Unexamined Patent Application Publication No. 2006-302235 | {
"pile_set_name": "USPTO Backgrounds"
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Field
Exemplary embodiments relate to a method for controlling a decoding process based on a path metric value, and, more particularly, to a method for terminating a decoding process of a control channel and reducing blind decoding overload based on a path metric value.
Discussion
A Long Term Evolution (LTE) system uses Physical Downlink Control Channel (PDCCH) as a format of downlink control channel. The downlink refers to a radio communication from a base station, such as an evolved NodeB (eNodeB), to a mobile device, such as a user equipment (UE) supporting a mobile communication, e.g., LTE standards technologies. The PDCCH includes Downlink Control Information (DCI), and various formats of DCIs transport control information for one or more UEs. In an LTE system, DCIs are encoded by tail biting convolutional code (TBCC).
A UE may use a Viterbi decoding algorithm to decode the received PDCCH by a blind decoding scheme. The blind decoding according to the Viterbi decoding algorithm typically includes more than one training operations followed by a maximum likelihood path finding and a trace back operation to determine information bits, which are the most likely bits transmitted from a transmitter. The determined information bits are checked by a Cyclic Redundancy Check (CRC) and the validity of the information bits are determined based on the CRC check result.
In the blind decoding of an LTE system, control channel element (CCE) number and the aggregation level corresponding to the encoded data are unknown. Thus, the blind decoder, such as the Viterbi decoder, determines various possible sets of PDCCH data (“possible candidates”) determined according to various aggregation levels and possible CCE numbers, etc. The possible sets of PDCCH data determined from the received data mapped in certain common search space and UE-specific search space are candidates for the blind decoding. The number of blinding decoding operations may vary according to the number of aggregation level and the number of carriers. In an LTE system, the number of blind decoding attempts is great and many blind decoding attempts yield useless results because incorrectly assumed parameters, such as an incorrect aggregation level, were applied. For these incorrect decoding attempts, the decoder wastes significant time and battery power. Accordingly, this blind decoding process is inefficient in terms of the decoding speed and power consumption.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to a surface acoustic wave device and a boundary acoustic wave device.
2. Description of the Related Art
In recent years, a wafer-level chip-size packaging (WLCSP) technology has been developed that reduces the size of a package of a surface acoustic wave device, such as a surface acoustic wave filter, and a boundary acoustic wave device, such as a boundary acoustic wave filter, to a component chip size.
For example, as shown in FIG. 13, a surface acoustic wave device includes a piezoelectric substrate 1 and a resin substrate 7 that faces the piezoelectric substrate 1. The piezoelectric substrate 1 includes a conductor pattern having an IDT (a comb-shaped electrode) 2, a reflector 3, and a pad 4 provided thereon. The resin substrate 7 includes an external electrode 8. The piezoelectric substrate 1 and the resin substrate 7 are bonded and sealed by light curable resins 6a and 6b. The pad 4 is electrically connected to the external electrode 8 (refer to, for example, Japanese Unexamined Patent Application Publication No. 2003-37471).
When such a structure in which a piezoelectric substrate is covered and sealed by a cover is applied to surface acoustic wave devices and boundary acoustic wave devices, capacitive coupling tends to increase. In particular, when the sizes of the devices are reduced by using a wafer-level chip-size packaging (WLCSP) structure, the capacitive coupling significantly increases. An increasing capacitive coupling deteriorates the isolation characteristics and VSWR. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to rotary machines and particularly to sealing of a medium flow path within the machine.
2. Description of the Prior Art
The design and construction of efficient rotary machines, and of gas turbine engines in particular, has historically required careful confinement of the working medium gases to the flow path of the machine to preserve aerodynamic performance and to protect the internal components of the machine from thermal degradation.
Typical construction details in a region radially inward of the working medium flow path of a gas turbine engine are shown in U.S. Pat. No. 3,515,112 to Pettengill entitled "Reduced Clearance Seal Construction." In a Pettengill type construction the radially inward ingestion of working medium gases into the internal regions of the machine is prevented by flowing air radially outward between the stator or stationary element and the rotor or rotating element of the machine. The air flowed outwardly is termed purge air and is supplied to the cavity at a pressure greater than the pressure of the local working medium gases in the flow path. The rate of flow of the purge air through the cavity is set by the minimized combination of pressure differential and flow area between the purge supply and the flow path. For example, if the minimized flow conditions in the Pettengill construction occur across the labyrinth seal, the rate of flow across the seal will establish the rate of flow through the cavity. Similarly, if the minimized conditions of pressure differential and area occur across the narrow passage between the relatively rotating components at the disk rim, the flow rate through the cavity will be restricted by the flow rate through the passage.
Within the cavity the purge air adjacent the rotating member is pumped radially outwardly in response to frictional forces between the air and the radially extending surfaces of the rotor. If the pumping rate exceeds the rate at which purge air is supplied through the labyrinth seal, a circulation zone is established within the cavity. The excess of pumped air over purge air is forced across the passage leading to the working medium flow path and radially inward along the stationary member. As the circulating air travels across the passage, a portion of the working medium gases is ingested and circulated with the cavity air. As this occurs, the temperature of the air within the cavity becomes elevated and the durability of the local components becomes adversely effected.
New concepts are continually sought within the rotary machinery art to minimize the performance losses inherently imposed upon the machine by flowing substantial amounts of purge air between the relatively rotating components to prevent ingestion of the working medium gases. | {
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1. Field of the Invention
Carpule syringe with equipment for detachably and positively holding the hub of a hypodermic needle.
2. Description of the Prior Art
Carpule syringes are a relatively new entry into the medical field. They have come to be widely used and accepted, particularly where syringes are to be loaded and used repetitively. Syringes of this nature facilitate repeated loading. They lend themselves well to rapid, simple and easy insertion of fresh doses of medicament and discharge of exhausted containers. A carpule syringe, also known as a cartridge syringe, is characterized by the absence, as in a standard syringe, of a fixed barrel in which a piston reciprocates. Instead, a carpule syringe includes a frame with a large side opening designed to transversely receive a pre-filled, i.e. loaded, cartridge, the ends of which are closed and hermetically sealed. After insertion in the frame, the cartridge is locked in place. The forward end of the cartridge is closed by a plug that includes a thin, easily penetratable, self-sealing membrane. The rear end of the cartridge is closed by a plug which is capable of slidable movement within the cartridge. The frame is provided with a reciprocatable shaft arranged to be engaged with the plug under the control of an operator so that when the shaft is pushed forwardly in the frame, it will push the plug forwardly and thereby apply pressure to the liquid medicament within the cartridge so as to dispense the same through a hypodermic needle. A special hypodermic needle is used which is located at the front of the frame. This needle has a hub between its ends which is screwed into the front of the frame. The needle includes a rearwardly extended pointed segment which pierces the thin membrane at the front of the cartridge when the cartridge is inserted in the frame so as to couple the needle to the liquid medicament. Such arrangement enables cartridge after cartridge to be inserted into the frame where it is immediately ready for use, to be used until exhausted and to be replaced with a fresh cartridge time after time, quickly and expeditiously.
Carpules, of course, like all other medical equipment, have their problems. A major problem is that the connection between the hub of the syringe and the front of the frame is a threaded one. The hub has a male thread and the frame has a female thread. One of these threads wears out after extended use, usually the thread on the frame. It seems a matter of fate that when the failure occurs it is at an inopportune time, namely, when the syringe is embedded in a patient's flesh. When this occurs, after injection, and the doctor or clinician tries to pull out the needle, all that he will succeed in doing is to pull the frame away, leaving the needle with the attached hub embedded in the patient's flesh. The needle now must be delicately removed from the patient, usually with considerable discomfort and anxiety to the patient. This happens with far too great frequency. It is the purpose of the present invention to avoid this particular difficulty.
One proposal has been made to solve the problem above mentioned. This is embodied in Lingley U.S. Pat. No. 2,806,473 in which a carpule type syringe uses a double-ended syringe needle the inner end of which is disposed to pierce the seal at the outer end of the cartridge and in which a clip on the frame presses a hub of the needle against the frame of the syringe. The problem is not the same as the problem with which applicant is concerned, inasmuch as applicant's problem is unique to a carpule type syringe in which the needle has a hub screwed into the frame of the syringe, so that the needle is used repeatedly and there is an erosion of the joint between the hub and the syringe frame, i.e. of the mechanical coupling between the hub and the frame. The same distinction is true of Macgregor U.S. Pat. No. 2,695,613. Kauffman U.S. Pat. No. 2,047,512 and Burnside U.S. Pat. No. 2,604,890 represent other approaches to the same problem which are not relevent because they are not designed to function with commercially available carpule syringes having a female threaded front end. Haines U.S. Pat. No. 1,591,761 discloses a hypodermic syringe which employs a clamp to lock in place a needle hub the frusto conical socket of which is seated on a frusto conical tip at the discharge end of the syringe barrel; however the syringe is not a carpule type syringe. | {
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This invention relates to well logging methods and apparatus and more particularly to nuclear well logging techniques to determine the presence of undesired water flow in cement voids or channels behind steel well casing in a cased well borehole.
Undesired fluid communication along the cased in portion of a well between producing zones has long been a problem in the petroleum industry. The communication of fresh or salt water from a nearby water sand into a petroleum production sand can contaminate the petroleum being produced by the well to an extent that production of petroleum from the well can become commercially unfeasible due to the "water cut". Similarly, in near surface water wells used for production of fresh water for city or town drinking supplies or the like, the contamination of the fresh water drinking supply by the migration of salt water from nearby sands can also contaminate the drinking water supply to the extent where it is unfit for human consumption without elaborate contaminant removal processing.
In both of these instances, it has been found through experience over the course of years that the contamination of fresh water drinking supplies or producing petroleum sands can occur many times due to the undesired communication of water from nearby sands down the annulus between the steel casing used to support the walls of the borehole and the borehole wall itself. Usually steel casing which is used for this purpose is cemented in place. If a good primary cement job is obtained on well completion, there is no problem with fluid communication between producing zones. However, in some areas of the world where very loosely consolidated, highly permeable sands are typical in production of petroleum, the sands may later collapse in the vicinity of the borehole even if a good primary cement job is obtained. This can allow the migration of water along the outside of the cement sheath from a nearby water sand into the producing zone. Also, the problem of undesired fluid communication occurs when the primary cement job itself deteriorates due to the flow of fluids in its vicinity. Similarly, an otherwise good primary cement job may contain longitudinal channels or void spaces along its length which permit undesired fluid communication between nearby water sands and the producing zone.
Another problem which can lead to undesired fluid communication along the borehole between producing oil zones and nearby water sands is that of the so called "microannulus" between the casing and the cement. This phenomenon occurs because when the cement is being forced from the bottom of the casing string up into the annulus between the casing and the formations, (or through casing perforations), the casing is usually submitted to a high hydrostatic pressure differential in order to force the cement into the annulus. The high pressure differential can cause casing expansion. When this pressure is subsequently relieved for producing from the well, the previously expanded casing may contract away from the cement sheath formed about it in the annulus between the casing and the formations. This contraction can leave a void space between the casing and the cement sheath which is sometimes referred to as a microannulus. In some instances, if enough casing expansion has taken place during the process of primary cementing (such as in a deep well where a high hydrostatic pressure is required) the casing may contract away from the cement sheath leaving a microannulus sufficiently wide for fluid to communicate from nearby water sands along the microannulus into the producing perforations and thereby produce an undesirable water cut.
There have been many attempts in the prior art to evaluate and locate the existance of cement channels. There have also been many attempts in the prior art to locate and confirm the existance of so called microannulus fluid communication problems. Perhaps primary among these attempts in the prior art has been that of the use of the acoustic cement bond log. In this type of logging operation, the amplitude of acoustic wave energy which is propogated along the casing from an acoustic transmitter to one or more acoustic receivers is examined. In principle, if the casing a firmly bonded to the cement and to the formations, the acoustic energy propogated along the casing should radiate outwardly from the casing into the cement and surrounding formations, thereby reducing the amplitude of the casing signal. However, if the casing is poorly bonded to the cement or if the cement is poorly bonded to the formations, a void space exists and the acoustic energy should remain in the casing and arrive at the acoustic energy receivers at a much higher amplitude than if a good cement bond existed between the casing, the cement and the formations.
Acoustic cement bond logging, however, cannot always reliably detect the existance of a microannulus which can in some instances permit undesirable fluid communication between water sands and nearby producing zones. If the microannulus is sufficiently small and fluid filled, the acoustic energy propagated along the casing may be coupled across it. Yet it has been found that even such a small microannulus can permit undesirble fluid communication between producing zones. Similarly, a poor quality cement job may go undetected by the use of the acoustic cement bond log if the cement sheath is permeated by a variety of channels or void spaces which are located unsymmetrically about its circumference. Such channels or void spaces can permit undesirable fluid flow while the main body of cement is bonded well to the casing and the formations thus propagating the acoustic energy satisfactorily from the casing outwardly through the cement and into the formations. Therefore, such means as acoustic cement bond well logging have been proven to be not entirely reliable for the detection of potential undesired fluid communication paths in a completed well.
Another approach to locating void spaces or channels in the cement sheath in the prior art has been to inject radioactive tracer substances such as Iodine 131 or the like through producing perforations into the producing formations and into any void spaces in the annulus surrounding the well casing. The theory in this type of operation is that if the tracer material can be forced backward along the flow path of the undesired fluid its radioactive properties may then be subsequently detected behind the casing by radiation detectors. This type of well logging operation has usually proven to be unsatisfactory however, particularly in loosely consolidated sand formations which is precisely where undesired fluid communication is most typically encountered.
In particularly permeable formations such as loosely consolidated sands, the producing formation itself can absorb most of the radioactive tracer material which is forced through the perforations. Very little, if any, of the tracer material can be forced back along the path of undesired fluid flow, particularly, if this involves forcing the flow of tracer against either formation fluid pressure or upward against the force of gravity. Therefore, such tracer logging techniques for detecting cement channels or voids behind the casing have usually proven ineffective in the prior art. | {
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1. Field of the Invention
This invention relates to a hanger for supporting sound absorbing panels and a horizontally moving sound absorbtion wall made possible by use of the hanger.
2. Description of the Prior Art
In recent years, industry has become increasingly aware of noise pollution, and, consequently, there has developed the need for effective sound absorption systems. In the past, such sound absorption systems have generally been sound absorption panels attached to a supporting structure such as a wall. In many applications, however, sound absorption is required in the middle of an already constructed room, in order to isolate a sound source, but there is an additional requirement that the sound absorption system be movable in order to enable the continuation of an established flow of goods or traffic that had developed prior to the recognition of the need to isolate the sound emitted from the sound source. In the past, the only two methods useful for accomplishing this goal were to construct a new wall and use conventional sound absorbing panels, or else use some type of drapery material, depending from the ceiling of the building. Construction of a new wall is expensive, and the use of the mere drape provides many disadvantages in lack of sound absorption qualities and in cost and lack of strength of the material when it is required to span large vertical distances.
Prior to this time, there has not been developed an efficient sound absorption system which has all of the advantages of prior sound absorption panels but which is readily relocatable to meet the industrial needs. The new and novel system provided by this invention is the first known system to fulfill all of the needs of the industry. | {
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Industrial and natural sources produce a wide variety of gas streams containing significant amounts or concentrations of H.sub.2 S. In some instances, the gas streams will also contain or be composed principally of steam, with H.sub.2 S and other non-condensible gaseous materials being present as contaminants. Geothermal steam, for example, comprises or is composed of steam with varying minor concentrations or amounts of non-condensible gases such as H.sub.2 S, CO.sub.2, CH.sub.4, NH.sub.3, H.sub.2, and N.sub.2.
While processing equipment which uses or disposes of such gases is commonly constructed of special materials which resist the corrosive character of H.sub.2 S, downstream usage or requirements may require the removal of the H.sub.2 S. For example, H.sub.2 S interferes with many chemical reactions and cannot be tolerated in a reactant gas. Again, even if tolerated in some operations, the H.sub.2 S-containing gas cannot be exhausted to the environment. For example, boiler exhaust gases containing significant quantities of H.sub.2 S must be treated before being sent to stack. In the case of geothermal steam usage, before the condensate derived from the spent steam can be processed for disposal, H.sub.2 S in the condensate must be eliminated.
A variety of procedures have been employed to treat or purify H.sub.2 S-contaminated gases. In some instances, if the stream comprises principally non-condensible materials, e.g., those mentioned, supra, with a significant concentration of H.sub.2 S, say 200 ppm by volume or more, the stream may be incinerated to produce SO.sub.2 from the H.sub.2 S. In such cases the SO.sub.2 may then be removed from the non-condensible stream by scrubbing, the remaining non-condensibles being vented or further processed. Where the non-condensible gases contain lesser quantities of H.sub.2 S, aqueous reactant systems which comprise regenerable reactants which react with the H.sub.2 S to produce solid free sulfur are preferable. Suitable reactants include polyvalent metal ions, such as iron, vanadium, copper, manganese, and nickel, and include polyvalent metal chelates. Preferred reactants are coordination complexes in which the polyvalent metals form chelates with specified organic acids.
Where the sour or H.sub.2 S-containing gas comprises or is composed principally of steam, steam condensation must be taken into account in any removal procedure. Thus, in one preferred system in use for exhaust geothermal steam, the exhaust steam is condensed in a combination condensation-H.sub.2 S removal zone, with removal of H.sub.2 S from the steam and/or condensate by an aqueous oxidizing iron chelate solution. Solubility of the H.sub.2 S in the condensate or combination condensate/chelate solution is determined largely by the type of condensation employed and, if direct contact of the steam with aqueous iron chelate solution is practiced, by pH of the aqueous oxidizing iron chelate solution. In general, the condensation of the steam is carried out under conditions such that the volume of H.sub.2 S dissolved is less than fifty percent by weight of the H.sub.2 S in the steam. The dissolved H.sub.2 S reacts with the Fe.sup.+++ chelate to form particulate sulfur, the H.sub.2 S remaining as a non-condensible gas being thermally incinerated to SO.sub.2. The SO.sub.2 is further treated with alkaline solution to convert the SO.sub.2 to easily disposable or further usable HSO.sub.3.sup.- and/or SO.sub.3.sup.-2 ions in solution. The process further features regeneration of the derivative Fe.sup.++ chelate in the condensate/chelate solution to Fe.sup.+++ chelate, and, importantly, utilizes sulfur from the condensate and other byproducts of the process to generate thiosulfate ion in solution, the latter being easily and safely disposed of without environmental contamination.
While the prior art schemes have many advantages, they still admit of improvement. For example, if the H.sub.2 S-containing gas contains a large proportion of H.sub.2 S, or if H.sub.2 S is partitioned increasingly, e.g., up to 95 percent or so by weight of the stream, to the incineration reactor, increased energy and chemical (alkaline solution) costs will be incurred. The invention, therefore, is directed to providing a more cost efficient approach to processing high H.sub.2 S content streams or to increasing the volume of the split of non-condensible contaminant H.sub.S from steam condensation processes. | {
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The group of organophosphorus cholinesterase inhibitors include certain esters of phosphoric acid derivatives, e.g., nitrostigmine (=diethyl-(4-nitrophenyl)-thiophosphate), better known under the names Parathion or E 605, but they also include tabun, as well as the phosphonic acid derivatives sarin, soman and VX.
Among other things cholinesterase-inhibiting phosphoric esters are used as insecticides in agriculture. Since they have a toxic effect on human beings too, the staff working in agriculture is subject to a basic hazard to life and limb; this is true all the more since these organic phosphoric esters can also be absorbed via the skin. As compared to insecticides, the compounds tabun, sarin, soman and VX which belong to the group of the so-called nerve warfare agents are distinguished by a particularly high toxicity. All of these compounds are more or less strong inhibitors of acetylcholinesterase, an enzyme which physiologically blocks the effect of the transmitter acetylcholine released at certain nerve endings. Most of the symptoms of poisoning caused by cholinesterase inhibitors are produced by an inundation with endogenic acetylcholine.
The basic drug therapy of such a poisoning consists in the administration of the parasympatholytic atropine, blocking the exceeding muscarinic acetylcholine effects (e.g., increase of secretion in the respiratory system, bronchospasm, inhibition of the central nervous respiratory drive). There is no suitable antagonist available to normalize the exceeding nicotinic acetylcholine actions (e.g., inhibition of the impulse transmission at the synapses of motorial nerves to the respiratory musculature and to other skeletal muscles up to a complete peripheral motor paralysis). The peripherally caused myoparesis can only be compensated by oximes, e.g., pralidoxime (PAM) or obidoxime (Toxogonin.RTM.) whose mechanism of action consists in a reactivation of the inhibited acetylcholinesterase.
However, this post-exposure therapy is not sufficient to ensure survival after poisoning with the double LD.sub.50 of soman (LD.sub.50 =dose which is lethal for 50% of the exposed subjects). The probability of survival after a soman poisoning increases only when a pretreatment with a carbamate, e.g., pyridostigmine or physostigmine, has taken place prior to the poison exposure, and when additionally the conventional antidote-therapy with atropine and an oxime is started immediately on occurrence of the first symptoms of the poisoning. The requirement with respect to the carbamate used in the pretreatment is that it should not have significant undesired effects at the highest possible, lasting protective action, in particular it must not impair reaction capacity.
Some of the organophosphorus cholinesterase inhibitors are distinguished by the fact that they split off alkyl residues after accumulation to the acetylcholinesterase, thus stabilizing the bond ("aging"). The aged esterase inhibitor complex cannot be reactivated by oximes. In case of poisonings caused by the nerve warfare agent soman, aging already occurs after 2 to 5 minutes. The therapy with atropine and oximes can considerably be improved by a preliminary treatment with indirect parasympathomimetics, e.g., carbamic acid esters, such as pyridostigmine and physostigmine.
Carbamic acid esters inhibit the acetylcholinesterase in a manner similar to that of phosphoric acids. However, the bond is of a shorter duration and completely reversible. The fact that the carbamates inhibit part of the acetylcholinesterase, if dosed suitably, and thus remove it from the reach of the phosphoric esters and phosphonates having a stronger and prolonged inhibition may well be a decisive factor for their protective action, provided that the pretreatment started in time.
Also, the treatment of poisoning caused by phosphoric insecticides requires prompt medical care in any case. Since medical care in case of harvesters cannot always be accomplished promptly, there is a need for drugs prophylactically counteracting an intoxication. The use of carbamic acid esters for this purpose has already been described (Leadbeater, L. Chem. in Brit. 24, 683, 1988). The same applies to the effectiveness of carbamic acid esters in the pretreatment of a soman poisoning in animal experiments (Fleischer, J. H., Harris, L. W. Biochem. Pharmacol. 14, 641, 1965; Berry, W. K., Davies, D. R. Biochem. Pharmacol. 19, 927, 1970). The effective dosage of drugs to be applied prophylactically should not impair reactivity and functional capacity. However, carbamic acid esters have a low therapeutic index. As compared to pyridostigmine, an increased protective action can be achieved by physostigmine, however, the side effects are more severe.
On principle, undesired parasympathomimetic effects of the carbamates can be repressed by combinations with a parasympatholytic (e.g., atropine, scopolamine).
DE-OS 41 15 558 describes a prophylactic antidote consisting of a combination of pyridostigmine or physostigmine and N-methyl-4-piperidyl-1-phenylcyclopentane carboxylate-hydrochloride or arpenal, sycotrol, carmiphene or benactyzine, and, as an additional compelling component, a tranquilizer, i.e., diazepam or clonazepam. The undesired effects of physostigmine or pyridostigmine can therefore not be suppressed by the mentioned parasympatholytics alone, for this reason tranquilizers are additionally administered, whose side effects are problematic too.
Accordingly, it is necessary to allow the prophylactic administration of carbamic acid esters or other indirect parasympathomimetics at a dosage causing a sufficient protection against organophosphorus cholinesterase inhibitors without undesired accompanying effects. | {
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The superior mechanical and strength-to-weight properties of carbon fibers has led to an important class of high performance fiber/matrix composites. These high performance composites are particularly useful for the production of aircraft and automobile body parts for which both strength and light weight are critical. Such composites enable manufacturers to produce relatively light weight structures without sacrificing strength. Consequently, much research has been directed to producing carbon fiber materials with ever increasing high performance properties and physical features that make them more valuable in commercial products and processes.
Various processes have been developed over the years for the production of high performance carbon fiber materials. One of the leading processes for producing high performance carbon fibers is the so-called PAN process wherein polyacrylonitrile (PAN) is used as a precursor fiber. The PAN process typically starts with a highly prestretched PAN fiber and consists of three steps. The first step is a stabilization treatment wherein the PAN fiber is heat treated in air at a temperature from about 200.degree. to 300.degree. C. for one or more hours. In the second step, the fiber is carbonized at a temperature above about 1100.degree. C. in a non-oxidizing atmosphere. The third step consists of a post heat treatment at temperatures up to about 2500.degree. C. to graphitize the fiber and give it its high performance properties. It is in this post heat treatment step that the chemical composition, the crystalline structure, and the mechanical properties, are strongly influenced.
Another method for producing high performance carbon fibers is referred to as the "ex-mesophase" method wherein pitch is spun into thread, then oxidized, carbonized, and graphitized. See for example French Patent No. 2,512,076.
High performance carbon fibers can also be prepared by a vapor-deposition method in which the fibers are produced by the thermal decomposition of a hydrocarbon on a substrate on which catalyst particles have been deposited. The catalyst particles are typically discrete particles of such metals as iron, cobalt, or nickel. One such vapor-deposition method teaches that carbon filaments are grown by exposing catalytic particles to a carburizing atmosphere. This is followed by exposing the filaments to an atmosphere whose carburizing potential is sufficiently high to deposit carbon from the vapor phase and thicken the filaments into a more longer and thicker fiber. See G. G. Tibbetts "Vapor-Grown Carbon Fibers", Carbon Fibers Filaments and Composites, edited by J L. Figueiredo et. al., NATO ASI Series E: Applied Sciences, pages 73-94, Vol 177, 1989.
While high performance carbon fibers have met with a degree of commercial success as reinforcing materials in fiber/matrix composites, they nevertheless suffer from, inter alia, delamination problems. Several attempts have been made to modify carbon fibers to improve their interlaminar properties. For example, U.S. Pat. No. 4,816,289 teaches a method of producing crimped fibers. While crimped fibers have improved interlaminar properties, they would nevertheless still suffer from an unacceptable degree of delamination.
Another process teaches the formation of graphite fibers onto which secondary silicon carbide whiskers can be grown. While such a structure would show a substantial improvement in interlaminar shear strength, they unfortunately suffer from a number of shortcomings. For example, the silicon carbide whiskers are formed as only single non-branched structures. That is, there is no branching of the whiskers themselves, nor are the whiskers in a spiral or helical form. The carbon filaments which are produced on the carbon fibers in the practice of the present invention are branched, spiral, helical, or a combination thereof. These branched, spiral, and helical filament forms enhance interlocking of the fibers in the matrix. Furthermore, in the production of silicon carbide whiskers, relatively high temperatures (i.e., >1000.degree. C.) are required. Still further, silicon carbide is intrinsically abrasive and thus leads to handling and processing problems. Other shortcomings include: (a) the thermal expansion coefficient of silicon carbide differs from that of carbon, and as a consequence, can initiate or propagate cracks in the resulting composite; (b) the densities of silicon carbide whiskers(ca. 3.22 g/cc) are considerably higher than those of carbon (2.25 g/cc); (c) at present, it is not possible to control silicon carbide whisker orientation and growth characteristics; and (d) the costs associated with producing secondary silicon carbide whiskers on carbon fibers is considerable. It is also believed that the bonding between the silicon carbide whiskers and the parent carbon fibers is non-chemical and thus would not be as strong as desired in certain applications.
Another process variation is taught in Sekiyu Gakkaishi, 28(5), 409-412, Egashira et. al, 1985, wherein carbon whiskers are grown on carbon fibers from the vapor phase catalyzed by iron sulfide. For example, the parent fibers are preoxidized with HNO.sub.3 at a temperature of about 120.degree. C. for one hour to facilitate supporting Fe on them. They are then impregnated with a 0.5 mol/L Fe(NO.sub.3).sub.3 solution, followed by reduction with hydrogen. A mixture of benzene, H.sub.2 S, and H.sub.2 are employed as the reactant gas. The whiskers, or filaments, produced are straight, non-branched filaments. That is, they cannot be characterized as being branched, spiral, or helical, as are the filaments of the present invention.
While the such methods of modifying carbon fibers do improve the interlaminar shear strength of the parent fibers to various degrees, there still exists a need in the art for high performance carbon fiber materials and structure with ever improved interlaminar properties and more economical ways of producing them.
There is also a substantial need in the art for high performance carbon filaments. That is, carbon filaments having high surface area and electrical conductivity. | {
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Depending on the required selected power class, mobile telephones emit transmission power levels of up to 2 W via the transmitting antenna. Particularly in the edge of the supply area of a radio cell or when transmission is interfered with by multipath propagation, the network system administration for the mobile telephone will often choose the highest power class in order to set up and maintain the connection.
If the antenna is in the form of a (shortened) monopole which is fitted externally on the telephone and if there is no interference in the environment in the immediate near field of the antenna, omnidirectional emission is achieved from the mobile telephone, that is to say emission in all directions. Since mobile telephones are normally used against the ear and against the head when setting up and maintaining communication connections, this equally results in undesirable radio-frequency irradiation of the head together with the organs located in it, for example the brain and the eyes. In this case, the assessment principle for the irradiation is the conversion of the radio-frequency energy from the electromagnetic field into body heat, which is indicated in the so-called specific absorption rate (SAR). Depending on the intensity of the irradiation, this leads to a local temperature increase in the head, associated with possible damage to the tissue (microwave effect). Furthermore, so-called non-thermal effects are also currently being discussed, whose possible effects on human health it has not, however, yet been finally possible to verify scientifically.
The majority of the previous methods for reducing the radiation load have been based on a specific configuration of the antenna and its surrounding area so as to jointly optimize the antenna structure and the mounting board with respect to reducing the radiation passing through the user. An integrated planar antenna element is normally used for this purpose, which is fitted on the rear earth side of the mounting board and thus, due to the screening effect of the board, preferably emits away from the head. If the antenna and the board are carefully designed and optimized jointly, together with the other parts of a mobile telephone such as the housing shell, the display and the keypad, it is possible to reduce the power emitted in the direction of the head. In this case, the main lobe direction remains permanently set.
The greatest problem with this method is often the immediate area surrounding the antenna: for example, the earthing configuration, which is normally too small and is thus poor for the frequency band, which is in the Gigahertz range, in the form of the mounting board in the mobile appliance results in major interaction between the antenna and the area surrounding the antenna or the mobile appliance. This interaction means that any change in the area surrounding the mobile appliance, which also includes the way in which the mobile appliance is fixed, in some circumstances may even lead to an increase in the radiation load, since the entire telephone then acts as an antenna and can contribute to emission in any direction, that is to say in particular it can even lead to increased emission in the direction of the user. The omnidirectional radiation characteristic of a mobile appliance normally changes considerably as soon as it is placed against the ear. The process of optimizing the antenna structure in conjunction with the configuration of the mobile appliance is thus carried out only for a single static case, in general with the mobile appliance being held in the ideal manner.
Patent Specification U.S. Pat. No. 6,484,015 B1 discloses an apparatus which envisages the use of a directional antenna with a main lobe direction parallel to the ground or two or more physically separate directional antennas with different main lobe directions parallel to the ground in a mobile radio. In the case of a directional antenna facing away from the user, the purpose of this antenna apparatus is to improve the efficiency as the ratio between the used power and the emitted power, and to reduce the radiation load for the user of the mobile station. The document relates to static directional antennas, whose directional characteristics are not variable.
The Patent Specification U.S. Pat. No. 6,489,465 B1 describes a method in which the user of a mobile telephone is requested to change his position if the antenna is poorly positioned. The mobile telephone antenna does not have a directional characteristic.
German Laid-Open Specification DE 101 23 107 A1 describes a mobile telephone which uses a directional antenna whose main lobe direction can be aligned in the direction of the fixed station by measuring the received power. The total radiation power can be reduced by the directional emission. However, in this method, interference influences can adversely affect the optimum antenna alignment as a result of the directional power measurement for location of the fixed station. | {
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(1) Field of the Invention
The present invention relates to a process for the production of ferritic stainless steel sheets or strips in which the production steps are simplified and products comparable or superior to products of conventional processes can be obtained.
(2) Description of the Prior Art
Cold-rolled products of ferritic stainless steels have heretofore been produced by box-annealing a hot rolled steel strip coil at 800.degree. to 850.degree. C. batchwise and repeating cold rolling and recrystallization annealing two times in many cases. Since a hot rolled steel strip has a heterogeneous micro-structure, if this strip is directly subjected to cold rolling, a desired formability cannot be obtained and therefore, batchwise diffusion annealing should be conducted for a long time prior to the cold rolling. However, in order to heat a long coil strip uniformly even to the interior portion of the coil and effect diffusion annealing, the coil should be kept in a furnace for more than 40 hours and thus the entire production time becomes very long, with the result that the manufacturing cost is inevitably increased.
As means for eliminating such disadvantage of long-time batchwise diffusion annealing of ferritic stainless steels, proposals have been made on the so-called continuous annealing process in which a coil is uncoiled and is continuously conveyed through a furnace, or sheets are conveyed one at a time through the furnace. In the following strips and sheets are therefor the equivalent of one another because in both cases a single layer of sheet-gauge steel is conveyed continuously through the furnace.
When a hot rolled strip of a ferritic stainless steel is subjected to continuous annealing instead of conventional batchwise annealing, the strip should necessarily be heated at a higher temperature than that adopted in the conventional process, and if this strip is heated at a high temperature, the ferritic steel is transformed into an austenite-ferrite mixed phase structure.
Japanese Patent Publication No. 30008/76 discloses a continuously annealing process in which a hot rolled strip of ferritic stainless steel is heated at a temperature of from 1330.degree. to 1350.degree. C. exceeding the austenite-ferrite mixed phase region for a short time of less than 3 minutes and the heated steel strip is air-cooled or rapidly cooled at an elevated cooling speed. Furthermore, Japanese Patent Publication No. 1878/72 discloses a continuous annealing process in which a hot rolled strip of ferritic stainless steel is heated at a temperature of from 930.degree. to 990.degree. C. where the austenite and ferrite phases co-exist, for a time shorter than 10 minutes and the heated strip is air-cooled or rapidly cooled at an elevated cooling rate. However, in these conventional continuously annealing processes the austenite phase formed at the annealing step is transformed to a martensite phase during the cooling step, and troubles are caused, for example, at the subsequent cold rolling step. They are rupture of a strip at the cold rolling step and intergranular corrosion at the annealing and pickling steps.
In the process disclosed in U.S. Pat. No 2,808,353, occurrence of such troubles is prevented because a hot rolled strip of ferritic stainless steel is heated at a high temperature of 927.degree. to 1149.degree. C. for from 1 to 10 minutes and is then annealed at 760.degree. to 899.degree. C. batchwise.
As the process using an additive element, a process comprising continuously annealing a hot rolled strip of a Ti-added ferritic stainless steel at 950.degree..+-.20.degree. C. for a time shorter than 10 minutes is disclosed in Japanese Patent Application Laid-open Specification No. 84019/73.
As described hereinafter, the present invention is directed to the production of Al-containing ferritic stainless steel sheets or strips. The use of Al as an additive element is discosed in, for example, British Pat. No. 1,162,562 and Japanese Patent Publication No. 44888/76. | {
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Patent document 1 (JP 2008-180596A, US 2008/0174450) discloses a PWM output type sensor circuit that outputs a PWM output signal, which has a pulse width associated with a value of a physical quantity, as information concerning the physical quantity.
Patent document 2 (JP H06-284100) discloses a technology implemented in a multiplex communication method, in which plural analog signals that should be transmitted are pulse-width modulated and then time-division multiplexed, the multiplexed pulse width-modulated signals are transmitted over a sole transmission line, the signals are received over the transmission line in order to detect synchronous information, and the plural pulse-width modulated signals are demultiplexed from the received signals on the basis of the detected synchronous information. According to the technology, while the timing of delivering the pulse-width modulated signal onto the transmission line is circulated among a greater number of timings than the number of analog signals that should be transmitted, the plural pulse-width modulated signals whose rising timings are controlled to be constant are delivered onto the transmission line at associated delivery timings, and a period during which no pulse-width modulated signal is delivered is detected as the synchronous information.
Patent document 3 (JP H07-7490) discloses a pulse multiplex transmission method. According to the pulse multiplex transmission method, in a transmitting unit, a first pulse width modulator sequentially multiplexes plural digital signals into a first pulse-width modulated signal stream, a second pulse width modulator sequentially multiplexes other plural digital signals into a second pulse-width modulated signal stream that has a reverse polarity of the polarity of the first pulse-width modulated signal stream, and a multiplexer multiplexes the first pulse-width modulated signal stream and second pulse-width modulated signal stream. In a receiving unit that receives a multiplexed pulsating signal produced by the transmitting unit, after an ac-coupled amplifier amplifies the multiplexed pulsating signal into a pulsating signal having a predetermined amplitude, a subtractor, a first pulse-width demodulator, and a second pulse-width demodulator sequentially separate the plural original digital signals from one another so as to reproduce the original digital signals.
Non-patent document 1 (“Surface Vehicle Information Report” from the Society of Automotive Engineers (SAE) International (J2716 Revised February 2008, SENT for Automotive Application)) discloses a single edge nibble transmission (SENT) communication technology for decreasing the number of communication pulses per unit time. Herein, since an output signal of a sensor is divided into plural pulsating outputs in units is of four bits, a pulse serving as a reference for correction is transmitted as a leading pulse, and a quantity to be corrected with the trailing pulse is supposed to be an estimate. When multiple data items are communicated, a message identification (ID) is assigned to each of the data items in order to treat the data items independently.
For communications among various kinds of sensors (for example, a pressure sensor, a temperature sensor, an optical sensor, and a slope sensor), which are mounted in a vehicle, and an on-board electronic control unit (ECU), signal lines are provided for the respective sensors.
However, in recent years, it is requested to decrease the number of signal lines by integrating plural sensors, and multiplex sensor output values (detection signals) of the plural sensors so as to communicate the sensor output values, and thus reduce a cost.
For example, when a pressure sensor output value detected by a pressure sensor is transmitted to the ECU, a change in a pressure is accompanied by a temperature change according to a gas state equation.
Therefore, it is requested to highly precisely implement various controls in a vehicle on the basis of an accurate pressure sensor output value. Specifically, the pressure sensor and a temperature sensor are integrated. When the pressure sensor is used to detect a pressure sensor output value, the temperature sensor is used to detect a temperature sensor output value at the same time. The pressure sensor output value and temperature sensor output value are multiplexed and communicated to the ECU, and the ECU corrects the pressure sensor output value on the basis of the temperature sensor output value.
In practice, a total of three wiring harnesses including a wiring harness that is an analog signal line over which analog signals of sensor output values are communicated, a wiring harness that is a positive power line, and a wiring harness that is a ground line are used to connect the sensors and ECU.
In the ECU, the analog signals of sensor output values are analog-to-digital converted. It is likely that the precision in digital signals produced through the analog-to-digital conversion may be degraded due to an adverse effect of noises convoluted to the ground line. Therefore, in the ECU, a digital filter is applied to the analog-to-digital converted signals in order to remove the noises.
However, when the number of data sampling times is increased in order to improve the noise removing performance of the digital filter in the ECU, the responsiveness of a sensor output value may be degraded.
After a sensor output value is converted into a digital signal, when the digital signal is transmitted to the ECU, the adverse effect of the noises can be avoided. However, high timer precision is needed in order to realize high-speed communication.
For example, when multiplex communication is performed by utilizing controller area network (CAN) communication, it is possible to correct timer precision. However, a circuit dedicated to the correction of the timer precision has to be included. The inclusion of the dedicated circuit increases costs.
The patent document 1 discloses a technology for convoluting information relevant to a value of a physical quantity to a PWM output signal by determining a crest value of the PWM output signal in relation to the value (temperature information) of the physical quantity other than a certain physical quantity (a battery current value).
According to the technology, a dedicated circuit has to be included in an ECU in order to detect the crest value of the PWM output signal. As a result, cost is increased due to the inclusion of the dedicated circuit.
For PWM communication between a sensor and an ECU, normally, an output comparison circuit is included in the sensor and an input capture circuit is included in the ECU. A timer clock is fed from different timer circuits to the output comparison circuit and input capture circuit respectively.
Therefore, even when the input capture circuit exhibits an excellent timer resolution, a variance occurs in the precision in a pulse width of a sensor output value due to a difference between the timer resolution of the input capture circuit and the timer resolution of the output comparison circuit. Restrictions are therefore imposed on an amount of data capable of being communicated. Therefore, the technology is not satisfactory for multiplex communication.
The timer resolution of the input capture circuit refers to a cycle of a timer clock of a timer circuit included in the input capture circuit. The timer resolution of the output comparison circuit refers to a cycle of a timer clock of a timer circuit included in the output comparison circuit.
A variance in the precision (timer precision) in the pulse width between the timer clocks produced by the respective timer circuits included in the input capture circuit and output comparison circuit respectively leads to a difference in the timer resolution between the input capture circuit and output comparison circuit. Therefore, the difference in the timer resolution refers to a timer-precision difference.
The technology in the patent document 2 addresses a problem that high-speed communication is hard to do because a communication time is extended by a time that is a sum of a time required to circulate the timing of delivering a pulse-width modulated signal onto a transmission line among a greater number of timings than the number of analog signals that should be transmitted, a time required to deliver plural pulse-width modulated signals, which have rising timings thereof controlled to be constant, onto the transmission line at the associated delivery timings, and a time required to send synchronous information.
The technology in the patent document 3 addresses a problem that a communication time is long and high-speed communication is hard to do. This is because since one pulse of a PWM signal is used to transmit or receive one bit of a digital signal, numerous pulses are needed to communicate all data items.
Another problem of the technology in the patent document 3 is that, since modulating or demodulating processing is performed using a pulse-width modulator or a pulse-width demodulator, an error is caused in the modulating or demodulating processing.
In addition, according to the technology in the patent document 3, since special circuits such as the pulse-width modulator and pulse-width demodulator and an ac-coupled amplifier have to be included, a cost is increased due to the inclusion of the special circuits.
The technology in the non-patent document 1 addresses a problem that, since numerous pulses are needed to communicate all data items, the communication time is long and high-speed communication is hard to do.
In addition, according to the technology in the non-patent document 1, since interrupt processing is performed for each pulse in an ECU, when high-speed communication is performed, the interrupt processing has to be performed frequently. Eventually, processing other than communication to be performed in an ECU is retarded. | {
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The present invention relates to the field of music. Specifically, this invention relates to musical games that allow players to play competitively to understand rhythms in music and enhance note reading.
This invention was made after 15 years of teaching students in a studio, with ages ranging from 3 to 18 years. Many students had difficulty understanding basic rhythms, and did not have a clear grasp of how lines and spaces worked. Most students could not remember types of notes or values and had difficulty relating notes to rhythms. When placed in theory classes, students found this boring and could not successfully relate music theory to actual playing.
I decided that with a game, the fundamentals of music would be more visual and fun thus enhancing learning. In the floor version of the game, notes would be large and colorful helping students to better relate to them. Rhythms would be interchangeable so students would be able to try simple rhythms and build those into more complex versions as their levels of understanding developed.
Tokens would be given at the end of each round, to help students or players compute note values thus enhancing the basis of rhythms. Notes and tokens would be color coded to help students remember note values easily.
Notes would be placed at different intervals on the board for each rhythm given to help students associate note names with pitch i.e. if a player jumps to C above middle C on the score and then to G below, this would help them to relate high movement with a high pitch and downward movement with a lower pitch, making it easier for students to equate the movement in the game with finger movement on an instrument like the piano or violin. Even a wind player like a trumpeter, could relate this game to playing on his instrument, since the amount of energy exerted to reach high pitches, could be equated with the amount of energy needed to jump to high notes on the board.
It is my expectation that this game will excite children, friends and family members to play and keep the art alive. | {
"pile_set_name": "USPTO Backgrounds"
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The invention relates to a memory cell protected against transient disturbances. | {
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Embodiments of the invention relate generally to diagnostic imaging and, more particularly, to a method and apparatus of multi-tasking on a medical diagnostic imaging system.
Diagnostic imaging systems may include computed tomography (CT) imaging systems, magnetic resonance imaging systems, x-ray systems, and PET systems, as examples. The invention described herein is described with respect to a CT system, however it is contemplated that the invention may be applicable to any imaging system.
Typically, in computed tomography (CT) imaging systems, an x-ray source emits a fan-shaped beam toward a subject or object, such as a patient or a piece of luggage. Hereinafter, the terms “subject” and “object” shall include anything capable of being imaged. The beam, after being attenuated by the subject, impinges upon an array of radiation detectors. The intensity of the attenuated beam radiation received at the detector array is typically dependent upon the attenuation of the x-ray beam by the subject. Each detector element of the detector array produces a separate electrical signal indicative of the attenuated beam received by each detector element. The electrical signals are transmitted to a data processing system for analysis which ultimately produces an image. The x-ray source and detector are mounted on a gantry, which rotates about the subject while the patient is axially conveyed through a center of the gantry.
Generally, the x-ray source and the detector array are rotated about the gantry within an imaging plane and around the subject. X-ray sources typically include x-ray tubes, which emit the x-ray beam at a focal point. X-ray detectors typically include a collimator for collimating x-ray beams received at the detector, a scintillator for converting x-rays to light energy adjacent the collimator, and photodiodes for receiving the light energy from the adjacent scintillator and producing electrical signals therefrom.
Typically, each scintillator of a scintillator array converts x-rays to light energy. Each scintillator discharges light energy to a photodiode adjacent thereto. Each photodiode detects the light energy and generates a corresponding electrical signal. The outputs of the photodiodes are then transmitted to the data processing system for image reconstruction. As such, imaging data is obtained of the subject while the subject is axially conveyed through the gantry.
The CT system is operated and data is acquired from the system using a console that is located in close proximity to the gantry. A user may use the console for accessing patient data or images, entering patient data, defining diagnostic procedures, and the like. The user may also use the console for running an imaging session and analyzing imaging data as well.
Currently, if a single user is using the medical diagnostic system, a second user must typically either interrupt the workflow of the first user to complete their task, or wait until the first user has completed their task, in either case delaying the completion of the diagnostic procedure. Thus, if the first user is using the system for, for instance, imaging data acquisition, the first user must be interrupted in order for the second user to access for instance information about the patient, or to enter information about a subsequently planned imaging procedure on the next patient. The interruptions can cause mistakes to be made in data imaging, data entry, and such, and cause system downtime and overall inefficient use of equipment.
Attempts have been made to solve this problem by displaying a separate floating window on a user interface of a console, and providing additional dedicated hardware such as a touchscreen, a mouse, or a trackball to allow interaction from a second user. Other attempts to solve the problem include locating a separate display in a second location and using a video cable to access information from the console. However, such systems can be expensive and can nevertheless result in distractions to a user of a console.
Therefore, it would be desirable to design an apparatus and method for more efficiently operating a diagnostic imaging system. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The invention is directed to method for producing a line of weakening by means of a laser such as is known from DE 196 36 429 C1 and to an airbag cover produced by this method.
2. Description of the Related Art
The invention is directed to method for producing a line of weakening by means of a laser such as is known from DE 196 36 429 C1 and to an airbag cover produced by this method.
The prior art discloses many airbag covers (hereinafter: cover) designed and produced in different ways. All of them have the object of safely preserving and protecting the airbag and, in case of activation of the airbag, releasing within milliseconds an opening through which the airbag can deploy and protect the passengers of the vehicle.
The trend in recent years has tended toward covers which are not visible to the passengers. Such covers are produced in that a line of weakening which defines the subsequent opening is generated in the cover (which generally comprises a rigid substrate layer, a foamed material layer and a trim layer or decorative layer) or in individual layers of the cover.
The difficulties involved in generating such lines of weakening with different techniques are discussed in EP 0 711 627 A2. It is mentioned that the scoring depth of the line of weakening must be carefully controlled in order to cause a reliable rupture of the outer cover layer (decorative layer) at exactly the right moment. On the one hand, the depth of the score should not be too shallow so that the resistance to be overcome in opening is not too great; on the other hand, sufficient material should remain so that the line of weakening is not outwardly visible. It is also mentioned that in cover layers having an irregular inner surface the scoring depth must be controlled in such a way that the remaining residual wall thickness is constant. By way of solving this problem, it is suggested in EP 0 711 627 A2 that a continuous groove be cut in by means of a laser beam, this laser beam being controlled to achieve a constant thickness of the material remaining below the groove and to achieve a constant groove depth.
In order to generate lines of weakening with different resistance to opening, the groove can be generated with different depths. At all of the depths mentioned by way of example, the substrate layer is completely penetrated and the foamed material layer is penetrated at least partially or is penetrated completely into the decorative layer. Since the groove is continuous in every case, excepting the above-mentioned alternative line of through-holes, which anyway does not meet the object of invisibility of the line of weakening, the residual wall thickness remaining below the groove can not be minimized to an unlimited extent for minimizing the opening resistance because otherwise the groove would be visible due to the residual material sinking into the groove. To the extent that the foamed material layer should be at least partially retained as a supporting layer for the decorative layer, no weakening of the decorative layer can take place. However, for more robust foils, it is necessary that these be weakened because otherwise the tearing force required would be too great. In order to weaken the foil, it is mandatory that the supporting foamed material layer in the area of the groove be completely removed, and the decorative layer will sink into the groove over the course of time even when the decorative layer is weakened only slightly.
The basic idea of retaining the foamed material layer as a supporting layer for the decorative foil in the area of the line of weakening leads to the idea of forming the line of weakening by means of blind holes or pocket holes.
DE 196 36 429 C1 describes the advantages of a line of weakening produced by removal of material to form pocket holes:
1. Whereas only the residual wall thickness in the cut joint (continuous groove) can be varied as a geometric quantity for influencing the opening resistance when the line of weakening is produced by incision (described, e.g., in EP 0 711 627 A2), the width of the bridging material or web remaining between the pocket holes can be varied effectively in the case of a succession of pocket holes (perforation line).
2. When material is removed in the form of a cut line, the residual material must be thick enough or strong enough that it does not sink into the cut joint and thus become visible. With the perforation line, this sinking in is prevented, even when the residual wall thickness is smaller, by the webs which remain between the pocket holes and which act as supports.
3. A tearing resistance which is constant along the entire perforation line can also be achieved when the pocket holes have different residual wall thicknesses that are repeated periodically.
The generation of pocket holes of different residual wall thickness is based on the idea that small residual wall thicknesses and narrow webs can lead to intense thermal loading, as a result of which, as with material fatigue due to aging, the residual material sinks into the pocket holes so that the line of weakening becomes visible. In order to prevent this, material removal is carried out while periodically changing to different depths in the decorative layer. At shallower depths, the widths of the webs remaining in the foamed material layer are appreciably greater and there is less thermal loading of the decorative layer. The risk of visibility is improved with only a slight increase in the tearing resistance.
However, as tests have shown in practice, the selected spacing of the pocket holes penetrating into the decorative layer must be very large so that a web of foamed material is actually maintained. The radiation energy needed for the removal of the substrate layer and decorative layer is so high that the foamed material layer burns copiously around the pocket hole. However, as a result of the large spacing between the pocket holes, particularly when using more robust materials for the decorative layer, the required opening force is excessive.
Both of the solutions presented above are compromises between the smallest possible residual wall thickness and a small web width so as to keep the opening resistance of the line of weakening low on the one hand and the residual wall thickness and web width sufficiently large on the other hand so that the line of weakening is not visible to the passengers.
DE 195 40 563 A1 shows an instrument panel for motor vehicles which is overlain by a foil and has an integrated airbag door. The foil (decorative layer) has a line of weakening formed by a row of perforation holes which completely penetrate the material. The inventive idea in this solution consists in reducing the visibility of the line of weakening by covering the line of weakening with a laser-treated track.
Again, with the aim of generating an invisible line of weakening, it is suggested in DE 196 36 428 A1 to generate a line of weakening which alternates with the actual predetermined breaking line and is similar to the surface structure of the detector layer. (In the solutions mentioned above, the line of weakening leads over the same line as the predetermined breaking line.)
The last two solutions mentioned above require higher expenditure with respect to apparatus and technique as well as longer cutting times. Invisibility is forfeited for the sake of a low opening resistance which can best be achieved by means of a through perforation. However, this is again produced by superimposing a second laser line which makes the line of weakening “disappear” or by a line which is hardly visible in the surface. | {
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The present invention relates to a resistance reel for exercisers, and wherein an extractive band is pulled out against an adjustable force of resistance and is rewound by a return, spring.
A resistance reel of this type is known, e.g. from French Patent No. 2 274 322, where a resistance reel with the above stated properties is disclosed. Friction disks in a resistance section have full annular faces which are forced towards each other by a spring arrangement comprising a number of helical compression springs which are provided between a friction disk that is non-rotatingly mounted on a shaft and a compression disk which is provided on the shaft and which may, by means of a control wheel cooperating with threads on the shaft, be moved to or from the compression springs to adjust the pressure between the friction disks and thus the braking effect and resistance to unwinding the extractive band. Such control means is bulky, and the frictional heat generated between friction disks during use of the resistance reel may propagate, via the shaft, to the surrounding casing and may heat the casing to a high temperature which is uncomfortable when the casing is touched. A clutch means between the resistance section and an unwinding section is achieved by a free wheel and is bulky. Furthermore, it is stated in such French reference that the shaft is mounted in a casing of the reel, and that the casing is secured to a firm support, e.g. to a rail on a wall where the level of the casing may be adjusted. The casing or a cover thereof thus has to be strong enough to absorb the tensioning force and the point of attachment of the casing on the firm support when the resistance reel is used. This means that the casing must have a sturdy design and the entire resistance reel will consequently be of a large volume. | {
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The use of endoscopes and similar medical instruments for diagnostic and therapeutic applications is well known in the art. Such devices are used for viewing virtually anywhere within the body. To eliminate the problems of cleaning and sterilizing these instruments between uses, it is known to cover these devices during use with sealed, protective sheaths, sleeves and covers of various sorts. Such sheaths are commonly elongated, tubular sleeves each having one open end for inserting the medical instruments and one closed, distal end. After use, the protective sheath is removed from the instrument and discarded. Thus, the cost of the protective sheath is an important factor in its utilization.
The protective sheath, however, must also meet several demanding requirements for safety and optimal effectiveness, and satisfying these standards has typically led to relatively high costs of production. First, because the endoscope often must be inserted far inside bodily cavities, the protective sheath must be relatively long in order to completely cover all of the endoscope that is inside the body. Of course, the sheath must also be made of a material that is non-toxic and substantially inert to bodily fluids.
Because the endoscope sometimes must be bent or snaked around bones, organs or other bodily obstructions to reach the desired internal location, it is desirable for the sheath to have some degree of flexibility. At the same time, for some applications, the sidewalls of the sheath should be relatively inelastic to avoid stretching or distortions while in use, which could lead to rupture of the sheath or to damage to the body. For similar reasons, for some applications, the internal diameter of the protective sheath should be larger than the diameter of the medical instrument, but should not be larger than required to accommodate the instrument.
Up to now, it has not been possible to prepare protective sheaths of adequate lengths, having very small internal diameters, and also having the desired balance between flexibility and inelasticity of the sidewalls. All of the protective sleeves currently in use are lacking in one or more of the following desirable characteristics: (1) optically transparent, thin-walled viewing "window"; (2) thin, flexible but relatively inelastic sidewalls; (3) smooth transitions and corners; (4) reliability--i.e. no leaks; and (5) easy and inexpensive to manufacture. Specifically, it is impossible to obtain lenses with side walls of almost any length and with sidewall thicknesses less than about 0.015 inches using conventional injection molding techniques, especially if optical transparency and high strength are important. Furthermore, injection molding requires a draft or taper along the sidewalls in order to eject the finished product from the mold. Vacuum-forming or thermoforming is another technique that can be used to produce clear packaging. However, this process generally results in relatively thick walls, generously-radiused corners, and, again, substantially tapered sidewalls.
In addition, because an endoscope is an optical instrument, the protective sheath must include at least one optically transparent viewing "window" at or proximate to the closed, distal end of the sheath and in alignment with the light source and window of the endoscope. The location of the optically transparent window of the sheath will depend, in part, on whether it is to be used with an end-viewing or side-viewing endoscope. In order to maintain optical transparency and minimize visual distortions, it is desirable that the viewing window of the sheath be substantially inelastic. At the same time, as with the sheath sidewalls, some degree of flexibility in the sheath window is desirable to facilitate maneuvering the sheath and endoscope through the body and, in many cases, helping to keep the window tight against the endoscope. Whereas glass lenses are optically transparent, they are even thicker than available plastic lenses, are rigid and non-deformable, and present a potential shattering hazard, especially when made thin.
In the prior art, as discussed below, it is typical to fashion the sheath window independently of the sheath and subsequently join the two elements using adhesives or thermal bonding. Obviously, this two-step process is relatively costly and time-consuming. This two-step manufacturing process also increases the risk of sheath failure along the bonded edge. All of the prior art endoscope covers also all have thick, rigid glass or molded plastic lenses and/or sidewalls that make these devices heavy, bulky and of limited utility. They cannot be used, for example, with most small endoscopes in small body cavities, especially because the adhesive joints also add to the thickness or diameter of the final unit. Thus, present technology can produce covers for endoscopes, but these covers substantially limit the performance of the instruments, especially those with very small diameters.
Typical of the prior art in this field are U.S. Pat. Nos. 4,646,722 (Silverstein et al.) and 4,907,395 (Opie et al.). The Silverstein et al. patent teaches the use of an endoscope sheath comprising a flexible tube surrounding the elongated core of an endoscope. The flexible tube has a transparent window near its distal end positioned in front of the viewing window of the endoscope. As seen in FIG. 2 of this patent, the sheath comprises a cylindrical support body 30 having a viewing window 32 mounted at one end and a roll of elastomeric material 48 secured to support body 30.
An alternative embodiment of the Silverstein et al. sheath for use with side-viewing endoscopes is shown in FIG. 10. In this embodiment, the sheath 110 comprises an end cap 112 of relatively rigid material mounted at the end of a flexible cylindrical tube of elastomeric material 114 formed into a roll 116. The end cap 112 includes a pair of transparent windows 118, 120. Although the Silverstein et al. patent does not describe how viewing window 32 is fastened to support body 3C, or how viewing windows 118, 120 are fastened to end cap 112, it is clear that these are separate and distinct components which are not formed continuously integral with the elastomeric tube. The later Opie et al. patent is essentially an improvement invention directed to a method of packaging and installing the endoscope sheaths of the Silverstein et al. patent.
U.S. Pat. Nos. 3,794,091 (Ersek et al.) and 3,809,072 (Ersek et al.) are directed to sterile sheaths for enclosing surgical illuminating lamp structures that have elongated light transmitting shafts. The sheaths in Ersek et al. are fabricated from films of flexible plastic material, such as vinyl tubing, polyethylene or polypropylene. The method of fabrications, however, is not disclosed. Ersek et al. prefer a wall thickness of between three and six mils for the required durability, rigidity and transparency. The tip end portion 20 of the sheath is described as a "generally rigid lens element") sealed to the sheath in a continuous sealing line 21 by thermal welding or adhesive bonding. Here again, it is clear that the tubular sheath portion 22 and lens element 20 are separate and distinct components which are not formed continuously integral with one another.
More importantly, the lens element here is rigid and thick.
U.S. Pat. No. 4,957,112 (Yokoi et al.) describes an ultrasonic diagnostic apparatus, the distal end portion of which includes a cover 24 made of a thin, hard, polyethylene sheet that has a window portion 34 along a sidewall. At col. 4, lines 55-58, Yokoi et al. describe window 34 as being "integrally formed" with the cover 24 for permitting the passage of an ultrasonic wave from the end of the instrument. Thus, window 34 need not be optically transparent; and, cover 24 covers only a relatively small distal portion of the diagnostic instrument.
U.S. Pat. No. 4,878,485 (Adair) describes a rigid, heat sterilizable sheath S that provides an outer casing for a video endoscope. The sheath includes a viewing window 32, a flat disc positioned at the distal end positioned in the optical path of the endoscope. Window 32 is described as a "rigid" cover made of glass, sapphire or polycarbonate. Once again, it is clear that cylindrical housing 30 and window 32 are separate components, and that the lens is thick and rigid.
U.S. Pat. No. 4,819,620 (Okutsu) describes an endoscope guide pipe which is rigid and formed from a transparent material such as glass or plastic. In one embodiment shown in FIG. 6, a pair of slots in the sidewall of the guide pipe is filled with a transparent material, such as glass, to define a window section 12f.
U.S. Pat. No. 4,470,407 (Hussein) describes a flexible, elongated tube with an elastomeric balloon sealingly mounted at the distal end of the tube for enclosing an endoscope. Inside the body, the balloon can be inflated to facilitate endoscope viewing. At col. 5, line 60-col. 6, line 22, Hussein describes a process for forming the balloon in which a polished aluminum mandrel is dipped into a latex formulation that is subsequently cured. FIGS. 4 and 5 show an alternative embodiment in which a tubular stem portion of the balloon 118 surrounds and extends substantially along the length of tube 114. In either case, the tube and the balloon are separate components.
U.S. Pat. No. 4,201,199 (Smith) describes a relatively thick, rigid glass or plastic tube 10 which fits over an endoscope. The distal end of the tube in the Smith patent is provided with an enlarged, sealed bulb 12 having a radius of at least 3-4 mm to reduce optical distortion caused by a too-small radius of curvature. Although the bulb 12 is formed continuously integral with tube 10, the rounded bulb is rigid, inflexible, thick-walled, and does not yield the same degree of distortion-free optical transparency as a substantially flat window.
U.S. Pat. No. 3,162,190 (Del Gizzo) describes a tube 19, made from molded latex or similar material, through which an optical instrument is inserted. Viewing is through an inflatable balloon element 24 mounted at the distal end of the tube. Finally, U.S. Pat. No. 3,698,791 (Walchle et al.) describes a very thin, transparent microscope drape which includes a separately formed, optically transparent, distortion-free lens for viewing.
Thus, the prior art patents describe endoscope sheaths that suffer from one or more of the following disadvantages: being comprised of separate sleeve and window elements that must be bonded together, having relatively thick and/or rigid sleeve sidewalls, having rounded or elastomeric windows that result in optical distortion, and having relatively thick and rigid and/or breakable windows. These and other problems with and limitation of the prior art are overcome with the protective sheath apparatus of this invention. In particular, the method of this invention produces a sheath having a thin-walled, close-fitting sleeve with a closed, distal end comprising a thin, substantially inelastic, optically transparent window formed continuously integral with the sidewalls of the sleeve, or with a portion of the length of the sleeve, and shaped to conform with the viewing window of an endoscope. | {
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This invention relates to chart recorders in general and more particularly to an improved chart lock system for an instrument operating under the control of a dedicated microcomputer.
In various types of instruments such as spectrophotometers, a chart is driven in synchronism with a scanning device such as a grating which scans through a range of wavelengths whilst analyzing a sample. Charts used with such chart recorders typically have marked thereon the associated wave number scales or other appropriate calibration. The response of the object under test is plotted as the ordinate value and the change of the scan position plotted on the abscissa. The abscissa markings thus must be synchronized with the drive of the scanning device. This becomes a particular problem where there is a change from the normal scan scaling, i.e., where operation is carried out on an expanded scale for example, or where a time drive is used to scan a particular wave number, for example, over a period of time. After changing modes, to go back to the normal scan, there is a need to accurately reposition the chart to the proper wave number. Without some type of a chart lock, this might require tedious adjustment by the operator and accuracy would then only be determined by his care and ability. The same problem exists when initially setting up the apparatus. Without a chart lock system, the accuracy from the beginning would be determined only by the operator's ability to position the chart.
Previously, instruments of this nature were driven by electromechanical means. The need for a chart lock was recognized and a solution to that problem is disclosed in U.S. Pat. No. 3,396,403 granted to M. A. Ford et al on Aug. 6, 1968. The device disclosed therein uses a mechanical arrangement wherein a spring loaded pin engages an opening in a drive wheel for the chart recorder to insure perfect alignment of a sprocket location, corresponding to a grid line, and the drive. Although this works well in the prior art systems, newer systems utilize microcomputers which have more recently become available. Although the prior art system could be used therein, such use does not fully take advantage of the microcomputer's capabilities.
Thus, it becomes evident that there is a need for a new and improved chart lock system which can be operated in conjunction with an instrument controlled by a dedicated microcomputer which will result in accurate chart positioning and which is easy to operate. | {
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The present invention relates generally to automatic turning machines and, more particularly, to multiple spindle automatic lathes. Still more particularly, the present invention relates to an arrangement for advancing rod stock pieces in such turning machines.
It has been proposed to feed a plurality of rod stock pieces to a work station of an automatic turning machine by advancing a movable slide member. The slide member has a hollow spindle which surrounds a respective rod stock piece, and a slip clutch mechanism which advances the surrounded rod stock piece only when the slide member is moved in direction towards the work station. The slide member is reciprocally moved by pressurizable air cylinders.
However, such prior-art constructions have the disadvantage that the feeding time is dependent upon many variables. For example, the time required to advance successive workpiece portions of the rod stock pieces depends upon the operating air pressure of the air cylinder units, the mass of the rod stock pieces themselves, and the frictional relationships between the moving parts. As additional workpiece portions of a single rod stock piece are cut away, the residual length of the respective rod stock piece becomes correspondingly reduced. This means that the mass and frictional characteristics of the residual rod stock piece are constantly decreasing, a fact which must be considered particularly during acceleration of the rod stock piece towards a work station.
For quick-working automatic turning machines, the clampable jaws which hold a respective rod stock piece must open and close within very short time intervals. The pressurized air cylinders of the prior art have proven to be highly unsatisfactory in advancing the rod stock pieces through such jaws in the required time intervals. In order to accommodate such quick-working machines, the air cylinders must be operative to accelerate the respective rod stock piece to extremely high values. This is further disadvantageous in that very high air pressure magnitudes are required which, in turn, causes the leading end of the respective rod stock piece to impact against an automatic stop of the turning machine with a relatively high impact force. In extreme cases, the leading end of the respective rod stock piece strikes the stop at such high energy that deformation of the leading end occurs. | {
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Industrial pumping takes many forms, all with the general requirement of transporting fluids or slurries through a process stream. Pumps are selected based on the application requirements including head pressure, metering accuracy, temperature, particle tolerance, fluid viscosity, cost, safety, service rate and a variety of other parameters. Pumps can generally be classified in two categories. Positive displacement pumps isolate discrete volumes of the working fluid and force them to move in a controlled direction. Kinetic pumps operate by adding kinetic energy to the system which creates a local increase in fluid velocity. Kinetic energy is converted to potential energy, i.e. pressure, at the pump output.
FIGS. 1-3 show a variety of different positive displacement pumps. In FIG. 1, a lobe pump is illustrated. This pump type is designed for low pressure, high volume applications where high particle loading may be an issue. The rotating lobes 2, 2′ of the pump head 1 are intentionally designed with loose tolerances to prevent physical contact and wear. The loose mechanical tolerance allows pressurized fluid to leak back to the low pressure side. This limits the pressure head the pump can reach generally to less than 20 bar. FIG. 2 illustrates a second type of rotary pump called an external gear pump. The pumping operation is similar to the lobe pump, but tolerances of the gear pump may be made arbitrarily close. As a result, gear pumps can obtain pressures heads of several hundred bar and pump fluids of viscosities from 0.05 to 100000 cP. Significant wear of the gears 3, 3′, especially at high pressure and temperature results in variable leakage back to the low pressure side. Both styles of rotary pumps can be isolated in sealed enclosures 4 and driven by magnetically coupled pump motors. This has the tremendous advantage of preventing external leaks of fluid without the use of dynamic seals. Magnetic coupling has lower torque limits than direct drive, however, so gear pumps are generally available only to less than 30 to 50 bar differential pressure. A final valuable characteristic to lobe and gear pumps is that they are considered both continuous and pulseless.
Reciprocating pumps, such as the one shown in FIG. 3, remain a primary industrial means of pumping fluids when high purity, high pressure [e.g. >100 bar to more than 1000 bar] and high precision [e.g. <1% flow variation] are needed. Reciprocating pumps come in several formats including mechanical and pneumatic piston pumps, and mechanical and hydraulic diaphragm pumps. Such pumps are characterized by having one or more heads 5 which transfer fluid between a low pressure input and a higher pressure output. Each pump head contains a means of physically adjusting the internal volume available to the pumped fluid. In operation, each pump head 5 uses a piston 8 driven by cam 9 that alternately aspirates fluid from the input 6 by increasing the available pump head volume, then dispenses the fluid to the output 7 by decreasing this volume. Most reciprocating pumps are designed to flow in only one direction. Flow direction is controlled by a series of check valves 6′, 7′ that isolate the pump head from the output pressure during aspiration and from the input pressure during dispensing. The output pressure is generally controlled, not by the pump, but rather by the downstream resistance-to-flow of the process flow stream serviced by the pump.
Reciprocating pumps are characterized by the number of pump heads they utilize. A pump with a single pump head is referred to as a simplex pump. Duplex, Triplex and Quad pumps refer to pumps with two, three and four heads respectively. Two or more pumps heads are required to provide pseudo-continuous flow since one pump head can be delivering while the other is aspirating. However, since the very nature of the movement involves stopping and restarting in opposing motions, reciprocating pumps can only emulate continuous rotary pumps approximately. In general, the greater number of pump heads for a given flow rate, the lower the pulsation of the output stream.
When fluid being pumped by a piston pump is relatively incompressible, these pumps are frequently referred to as metering pumps, since the volumetric flow of the fluid is presumed to match the mechanical volumetric displacement of the piston or diaphragm in the pump head. An excellent example of a metering application of a reciprocating pump is a low pressure syringe pump, in which a glass syringe draws in an aqueous solution and dispenses it very accurately to a downstream reservoir. Under this low pressure use [generally less than 2 bar] the volumetric compression of aqueous solutions is almost immeasurable and thus the presumption of accurate displacement is correct.
When reciprocating pumps are used with very compressible fluids such as permanent gasses, they are frequently called compressors or gas boosters. Gas boosters represent an ideal example of the influence of fluid compressibility on pump performance. In this case, the typical application is to increase the pressure of the gas between the input and output. A fundamental characteristic of gas boosters is the compression ratio. The compression ratio is simply the ratio of the maximum fluid volume a pump head can isolate between its check valves at the peak of its intake stroke to the minimum volume it can reduce to at the end of its delivery stroke. Hence, a compression ration of 7:1 indicates the total volume at intake is seven times greater than the residual fluid volume at the end of delivery.
FIG. 4 displays the compression or delivery stroke of a pump head in a gas booster. In this figure, the pump head 10 is comprised of cylinder 12, piston 14, and input and output check valves 16 and 18 respectively. During the delivery stroke, the cylinder internal volume has three distinct regions: compression volume 20, delivery volume 22 and residual volume 24. During compression, volume is systematically decreased and thermodynamic work is performed on the fluid and it tends to heat up. Higher temperature and lower volume cause an increase in the fluid pressure. The effect of the temperature increase is that the fluid reaches the delivery pressure earlier in the pump stroke than calculated by a simple isothermal volumetric displacement. If no heat were lost to the piston or cylinder walls the heating would be called adiabatic heating, which can be readily calculated from entropy tables for a given gas. Heat generated in the fluid is generally a source of inefficiency since it delivers the gas at a considerably lower density than desired. A cooling step is frequently required in the boosting process to remove the waste heat of compression so that downstream vessels can be filled more densely with the pressurized gas.
It is nearly impossible for a robust pump head design to leave no residual fluid at the end of the delivery stroke. Too close machining tolerances can cause a greater rate of wear and early failure of sealing surfaces. FIG. 4 shows the residual volume of gas remaining at the end of the piston stroke. In general, for gas pressure boosting applications it is very desirable to make this volume as small as possible and to make the compression ratio large. Hot residual gas in the pump head causes a further decrease in pumping efficiency, since it must first expand to below the input pressure before new fluid can enter the pump head during aspiration. Finally, compressive heating of the pump head itself will warm the entering gas to a lower density and reduce the amount of fluid entering with each aspiration.
An examination of the output flow of a gas booster reveals the ultimate difficulty in pumping compressible fluids. For each pump head, the aspirate stroke is expected only to fill the pump head volume and not deliver fluid to the output. The dispense stroke, on the other hand, is expected to deliver fluid to the output. In a piston based gas booster, as the piston moves forward to expel the fluid, temperature and pressure rise, but no fluid is released until the output pressure is reached. If the input pressure is 1 bar and the output pressure is 2 bar, almost half the piston stroke is used just to compress the fluid before delivery begins. As output pressure rises, a smaller and smaller volume of the delivery stroke is released to the output stream. By the time an output pressure of 7 bar is achieved in a booster with a 7:1 compression ratio almost the entire stroke is used for compression with little or no volume released to the output stream.
If aspiration and dispense strokes are of equal duration, fluid is delivered only 25% of the complete pump cycle in the 2 bar case. Even in a duplex booster pump, flow would only occur 50% of the time. By the time 7 bar output pressure was achieved, the pump would be delivering <1% of the time. As a result, most booster pump applications are pressure based and not flow based. These are not considered metering pumps at all since the work for compression makes it impossible to reliably calculate the volume of delivery per stroke.
Some applications require pumps that can meter fluids continuously and accurately at high pressure. For all fluids, including gasses, liquefied gasses, liquids and supercritical fluids, pressurization results in corresponding decrease in volume and increase in temperature to some degree. In general the compression effect is orders of magnitude different between permanent gasses such as Helium, liquefied gasses such as liquid carbon dioxide [LCO2] and true liquids such as water. At high enough output pressures, however, even water must be measurably compressed before being delivered to an output flow of a pump flow stream.
Water essentially behaves like a spring with a definable force constant that indicates how much volume change will occur per applied unit of pressure. This force constant is referred to as compressibility and is often reported in units of inverse bar [bar−1]. The generally accepted compressibility value for water at 20 C is 46×10−6 bar−1. Hence at 1 bar additional pressure, a volume of water would reduce 0.0046%; at 10 bar 0.046%; at 100 bar 0.46% and at 1000 bar 4.6%. In fact, water does not behave as a perfect spring and the compressibility value tends to become smaller at very high pressure so the 4.6% volume change is somewhat overstated, nevertheless it is clear that between 100 and 1000 bar a measurable portion of the dispensing pump stroke will be dedicated to compression of the water and thus cause an interruption to the continuous flow of a standard duplex pump. Water is considered one of the more incompressible liquids. Table 1 lists compressibility values for other representative organic solvents at 20° C. Generally these organic solvents range from two to three times more compressible than water.
TABLE 1Compressibility valuesfor various pure liquids at 20 C.CompressibilityLiquid(×10{circumflex over ( )}6 bar −1)Water46Tetrahydrofuran93Acetonitrile99Benzene94-95Chloroform 97-101Methylene97chlorideCarbon103-105tetrachlorideEthanol110-112Methanol121-123Acetone123-127n-Heptane140-145n-Hexane150-165Diethyl ether184-187
In practical terms then, for a reciprocating pump, compressibility is the fraction of the piston stroke required to increase the fluid pressure to delivery pressure. Compressibility compensation refers to reducing the period of deficit flow and/or adding extra flow to the flow path to compensate for this deficit. Also for the purpose of clarity, a compressible fluid shall be defined in terms of the fluids density variation in going through the metering pump and the corresponding need for compensation. It is common for high pressure metering pumps to have specified volumetric flow accuracy relative to the operational or maximum flow value. Without further calibration, pumps must rely on the assumption that mechanical displacement is equivalent to fluidic delivery. Hence a pump specified to 1% accuracy could not compress the aspirated fluid by more than 1% during the piston delivery stroke. Compressible fluids would be those that exceed this amount of compression [and corresponding change in density] during a delivery stroke. As a result, compressibility compensation is required to bring the pump to the operating specification.
Whether a fluid is compressible by this definition is tied to the delivery pressure of the fluid. A single fluid aspirated from an atmospheric reservoir, may be below this compressible fluid threshold at low delivery pressures but above it at high delivery pressures. For example, for a pump with a 1% accuracy specification, water [compressibility=46×10−6 bar−1] does not become compressible until it reaches approximately 225 bar, while hexane [compressibility=150×10−6 bar−1] becomes compressible at approximately 65 bar. When a fluid's compressibility exceeds the pump specification at some operational level, some action must be taken to adjust the pump's performance. This corrective action is generally referred to as compressibility compensation.
Values of the compressibility for a given liquid are dependent on both temperature and pressure. Generally as pressure increases the compressibility value goes down while at higher temperatures the value increases. Other factors such as dissolved gasses in the liquid can affect the compressibility value. Mixing two or more liquids can have unpredictable effects on the solutions compressibility. Table 2 shows the very nonlinear behavior of mixtures of water and methanol at 20 C.
TABLE 2Compressibility Valuesfor Water:Methanol MixturesWater-methanol,Compressibility(v-v)(×10{circumflex over ( )}6 bar −1)100-0 4680-204060-404650-505240-605620-808610-90117 0-100121
Many laboratory and industrial applications require continuous high pressure flow of fluids similar to those listed in Tables 1 and 2. One example is high pressure mixing of fluids, where periodic lapses of flow from one process stream will cause significant local concentration variability. Such variability can lead to improper dosage levels of active pharmaceutical ingredients or imbalance in the ratio of reactants in chemical flow reactors. At the laboratory scale, a prime example of the need for continuous high pressure flow is the case of high pressure metering pumps used in high performance liquid chromatography [HPLC]. Modern HPLC systems are commonly comprised of two separate pump modules to allow the high pressure, controlled mixing of two solvents at a time to create a well mixed mobile phase for chromatographic elution.
FIG. 5 shows the basic components for an HPLC pump of prior art. HPLC pump 30 is an example of an electric cam driven pump. In this case motor 32 rotates shaft 34 to rotate eccentric cams 36 and 38 to provide a reciprocating motion of pistons 40 and 42 contained in pump heads 44 and 46 respectively. As each piston aspirates, fluid is drawn from fluid reservoir 56 through input check valve 48 or 50 respectively. Output check valve 52 or 54 remains sealed during aspiration. During the delivery stroke, input check valve 48 or 50 is shut while output check valve 52 or 54 opens to deliver fluid to process stream 58. The cam drive shown in FIG. 5 is just one example of an HPLC pump. Others would include ball screw drives, pneumatic drives and hydraulic drives coupled to the pistons 40 and 44. Much of the remaining discussion focuses on pumping a fluid using compression compensation of laboratory-type HPLC type pumps that are similar in design to pump 30.
Requirements for pumps used in typical laboratory HPLC instruments are very demanding. Pumps must be able to deliver at very high pressures [up to 400 bar for traditional HPLC and as high as 1000 bar for recent ultrahigh performance LC systems]. A 2000 bar ultrahigh performance LC system is expected. HPLC pumps must also be able to handle fluids of ultra-high purity without contributing detectable contamination. In addition, for a given flow rate, the volumetric delivery of fluid is expected to remain constant within narrow limits [<1% variation] across the majority of the operational pressure range. Finally, the same pump is also expected to vary flow precisely over at least an order of magnitude of range in periods as short as one minute. This is the result of the need for a technique called gradient elution in which the two solvents controlled by separate pumps are systematically adjusted in relative composition from a weakly to a strongly eluting mixture while maintaining a constant combined flow rate.
An interesting effect of the mixing of two different solvents is that the viscosity of the combined mixture may vary widely over the course of the gradient run. As viscosity increases the resistance to flow of the chromatographic system causes a pressure rise. Thus even as one solvent is decreasing in its flow rate during the gradient elution, the pressure the pump experiences can be rising. FIG. 6 displays the viscosity behavior of various compositions of two binary mixtures: water:methanol 62 and CO2:methanol 64. Mole fraction of methanol is graphed on the x-axis and viscosity in millipascal-seconds is graphed on the y-axis 68. For typical HPLC applications, the water: methanol plot 62 clearly demonstrates extreme nonlinearity that can occur over the range of compositions. Each pump must be able to adjust to both varying output pressure and flow during gradient runs. Further, most long term applications require that the pumps must repeat this performance within a specification limit over their useful lifetime in order to provide truly valid data for the HPLC system.
In order to meet such demanding performance specifications, Modern HPLC pumps must address the issue of compressibility. Compounding the problem of compressibility is the fact that a majority of standard HPLC pumps have compression ratios less than 3:1. This means that there exists a minimum residual volume of 50% of the full stroke volume of each piston that never leaves the pump head's internal volume. This residual volume must be compressed and expanded on each stroke which adds a burden of at least 50% to the compressibility compensation effort. This sets a significantly lower limit for a given fluid on the maximum pressure at which it may be effectively pumped.
To counter the periodic flow lapses resulting from fluid compressibility, pump manufacturers have devised a number of techniques to suppress their negative effects. Pulse dampeners are routinely used in high pressure equipment to attenuate the pressure fluctuations associated with periodic discontinuities in flow. Pulse dampening attenuates pressure noise from the system, but does not always correct flow issues. Consider the case of pumping a moderately compressible liquid at high pressure. The piston is set to deliver at a fixed rate of displacement to achieve the desired flow. Since the compression part of the stroke delivers no flow without makeup or compensating flow, followed by the delivery portion which delivers at the correct flow rate, only negative flow pressure pulsations are seen at the pump output. No amount of pulse dampening will smooth the flow to the desired flow rate. It will always be less than required. A common technique to counter this issue is simply to increase the mechanical rate of the piston so that the average flow matches the expected flow. However, as seen earlier, the amount of compression needed per stroke varies with output pressure. As a result, very specific knowledge of the fluid characteristics would be needed to make this correction at all flows and pressures.
Simple correction to improve average flow also neglects yet another problem, local variations in the flow compositions. It is a frequent practice to place a single pulse dampener in binary pumps [a single pump module which contains two separate duplex pumps] at a location downstream of the mixing point of the two fluids. Thus each flow lapse of one pump due to compression results in a segment of flow that is dramatically enriched in the other fluid. This local enrichment, especially of high strength elution solvents can cause serious perturbations of the separation in HPLC. Further, since composition changes usually are accompanied by detectable changes in the refractive index of the fluid, significant noise can be experienced at any optical detectors in the flow system. This noise typically limits the ability of the system to detect very small quantities of material in the flow stream.
To limit the effect of compression, HPLC pump manufacturers have also attempted to shorten or eliminate the compression time. This has been done by accelerating the piston displacement during compression to minimize the period of flow lapse. Again, while a fixed acceleration period is useful over a limited range of pressures, in order to compensate over the entire pump range the acceleration period must be proportional to the output pressure. This feature has been accomplished in some modern HPLC pumps which can allow entry of CCF values up to 150×1−6 bar−1.
In the last several years, much focus has been placed on new ultrahigh performance chromatographic systems extending beyond the 400 bar pressure limit. This change has dramatically increased the awareness of compressibility as a major factor in pump performance. Traditional pumps have been redesigned to improve compression ratios. Special calibration algorithms have been adapted to determine empirically the compressibility of fluids over the entire range of pump operation to account for the actual nonlinearity of compression correction factors.
One area that has not been well addressed in the pursuit of higher pressures is the thermodynamic work that must be performed on the pumped fluids. As ultimate pressures reach 1000 or even 2000 bar, even well behaved fluids such as listed in Table 1 experience significant compression. Just as in the gas booster example above, significant compression, especially at the accelerated rate required for compression compensation, can result in significant heating of the fluid. Heating in turn leads to variability in fluid density and compressibility. Further, heat generated in the fluid during compression can communicate to pump head walls and warm incoming fluid further affecting density. Over the course of variable gradient flow, such factors are continuously varying and make it quite difficult to determine precise composition of the mixed components of the binary mobile phase.
Compressibility levels encountered in ultrahigh performance chromatographic systems are very similar to those encountered in supercritical fluid chromatography (SFC) over the last twenty years. SFC is a subset of traditional HPLC that uses liquefied CO2 as one of the components of the mobile phase. As a liquefied gas, CO2 must be delivered at high pressure to the pump head in order to remain in the liquid state. This is normally accomplished by connecting a tank containing both liquid and vapor CO2 in thermal equilibrium. A dip tube in communication with the CO2 liquid of the tank is plumbed directly to the pump head. Generally, chilling of the pump head and pre-chilling of the fluid are necessary to insure that CO2 remains in the liquid state during pump aspiration. Special grades of high purity CO2 are used in SFC to prevent dissolved components of less pure CO2 from affecting the optical clarity of the mobile phase. Mixtures of CO2 and common organic solvents also tend to have higher changes in refractive index than corresponding water: organic solvent mixtures so that small rapid variations in composition are more observable with optical detectors.
As mentioned, pumping of liquid CO2 takes special precautions to insure a continuous liquid supply into the pump head. The compressibility of liquid CO2 is also a major factor since it is typically as much as ten fold higher than most of the organic liquids mentioned in Table 1. Further, compression of CO2 between 60 bar [approximate tank pressure] and 400 bar [the maximum system pressure] can raise the fluid temperature more than 25 C. Such a temperature rise dramatically alters the density of the delivered fluid and introduces even more requirements for pump control.
The vast majority of commercial SFC pumps are modified HPLC pump designs. One manufacture uses the equation of state of CO2 to calculate fluid compressibility at various pumping pressures. A second manufacturer uses mass flow sensors to determine the average mass flow of the system and adjusts the pump speed to maintain a controlled average mass flow. Another reported technique is to use a specialized duplex pump where each piston is controlled by an independent motor. Pressure sensors allow the filling pump head to pre-compress the fluid to 90% of the output pressure as part of the filling sequence. Triplex pumps are reported that allegedly further reduce flow pulsation. Special algorithms have been created to surge pumps slightly beyond full compression to add a small excess of CO2 flow immediately adjacent to the CO2 deficient region and then allowed the segments to mix by longitudinal diffusion. For all the efforts to date, SFC analysis is still considered to be of lower sensitivity and poorer quantitation limits than standard HPLC. A significant reason for this is higher baseline noise directly related to the methods employed to fully compensate for compressibility.
In most reciprocating pumps an extra flow is added at the end of the compression stroke to compensate for the lack of flow during compression. Without this compensating flow, the pump will deliver inaccurate flow and compositions which become unintended functions of the delivery pressure. Thus, there is a period of no flow, followed by a period of excess flow. The two are intended to cancel each other out. While such compensation assures accurate flow and composition, it increases short term flow and pressure noise, which increases detector noise and degrades detection limits. The much higher compressibility of CO2 compared to normal liquids used in HPLC results in a much longer lapse and larger compensating flow, accounts for most of the degradation in detector noise previously observed in SFC.
Despite the poorer limits of detection, SFC enjoys high popularity in the areas of both preparative separation and analysis. SFC is the technique of choice in the rapidly growing area of chiral separation. This technique is also shown to be two to five times faster than traditional HPLC in separating both chiral and achiral mixtures. In fact, SFC competes favorably with the most advanced state-of-the-art implementations of ultrahigh performance chromatographic systems without the need for extreme pressures, special separation columns and vendor specific consumable hardware. As a result, a high interest remains for this technique if it can be brought closer to the low levels of quantitation available to HPLC.
The general steps of pumping with a piston pump involve aspiration of working fluid into the pump chamber, compressing the fluid to the pump output pressure and delivering the compressed fluid to the output flow stream. In the course of this process thermodynamic work is performed on the working fluid which results in temperature and density changes of the fluid. In addition, the amount of work and corresponding physical change done to the fluid is dependent on both total pressure rise required within the pump head and the physical characteristics of the fluid itself. This variability leads to the poorly metered pumping of fluids of unknown density and requires use of correction factors that are generally inadequate to provide pulse free flow from the pump head. As a result, both systematic and local variations in composition can easily arise in the mixed flow stream of binary and ternary pump systems.
While this discussion has focused a great deal on the needs of low-noise, precise, continuous high pressure pumping in chromatography, the need is truly general. Thus, there is a need for a solution for metering a compressible fluid without the variations that degrade overall quality of the process stream and frequently require addition of further components to correct this quality at the expense of speed, cost or energy efficiency in the process stream. | {
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A particulate tape is a ribbon or sheet of a particulate material in which the particles are held together, for example, by a polymer binder or matrix.
Particulate tapes are used in the manufacture of a variety of products. In the simplest case, the particulate tape itself can be the product. An example of this is magnetic recording tape which is used in tape form in video cassettes or cut into disks for use as media in computer floppy disks. This tape is made up of magnetic particles in a polymer matrix with a polymer film backing for strength.
Another use of particulate tapes is as an intermediate in the manufacture of more complex parts, particularly ones having a laminate structure. This can include structural components such as shells or panels made by tape lay up, or tubular structures made by tape winding. These structures can be used “as is,” however, it is usually desired to form a dense part having only the properties of the material that is contained in particulate form. In this case the laminated part will go through a process whereby the binder is removed, followed by a heat treatment to sinter the particles, thereby forming a solid, dense structure.
One of the more complex and demanding uses of particulate tapes is as the layers in the manufacture of multi-layer electronic devices and circuits. Multi-layer fabrication can be used to make single element electronic devices such as inductors, resistors, capacitors, transformers and transducers, for example. Multi-layer fabrication can also be used to make parts that include more than one device and more than one kind of device, along with conductor paths to connect these devices. The tapes used to form these parts must incorporate patterns of different particulate materials both in the plane of the tape and through the thickness of the tape to connect adjacent layers.
The current method of manufacture of these multi-layer electronic components begins with making a generally uniform, single component particulate tape. There are several possible methods for making these tapes including: waterfall casting, dip coating, and spraying, for example. However, the most common process is doctor blade tape casting, which is now described. An example doctor blade apparatus for casting a tape is shown in FIG. 1.
The first step in casting a particulate tape is forming a slip (or slurry) which is a suspension of the powder (particulate) material of which the tape is to be made. The slurry typically includes the particles, a solvent to make the slurry fluid, an organic dispersant that coats the particles so individual particles can slide over and past each other in the slip, and a binder to give the tape the mechanical properties necessary for handling after drying. The solvent dissolves the binder and has sufficient volume and sufficiently low viscosity to allow the slurry to flow. As the slurry dries, the binder coats the solid particles and bind them together.
To cast a tape, the slip is placed into a hopper having an open bottom end placed over a moving carrier. At the trailing edge of the bottom of the hopper, there is a small gap parallel to and just above the surface of the carrier. The height of this gap can be adjusted by moving a doctor blade, located at the top of the gap, up and down. As the carrier passes under the slip hopper, it draws a layer of the slip with it. The thickness of the layer of slip on the surface of the carrier is determined by the height of the doctor blade and the flow characteristics of the slip. The result is a thin, uniform layer of slip on the surface of the tape carrier.
Once the slip is cast onto the carrier, it is dried to form a tape that can be handled in the subsequent processing steps. As the layer of cast slip is conveyed on the carrier away from the hopper, the solvent evaporates. This evaporation can be controlled by passing the tape through an elongated, temperature and atmosphere-controlled drying chamber. During drying, the particles are typically pulled together to final density by capillary forces.
To create electronic devices from the cast tape, additional components need to be added to the cast tape. For example, for multi-layer capacitors, particles of a conductive material need to be printed onto the surface of a tape to form inner metal electrodes in the final sintered device.
If internal interconnections between layers are needed in the final device, vias must first be added. Vias are formed by mechanically punching holes in the tape and refilling the holes with a particulate paste. This paste contains a powder which, when sintered, will electrically or magnetically interconnect two layers.
After the vias have been punched and filled, patterns of conductors and other materials are printed on the surface of the tape. These additional features are printed onto the surface of the tape in the form of a thick film ink or paste. While there are a variety of printing processes that can be used, the most commonly used process is screen printing. In this process, a thin metal screen is pressed against the tape. The screen has a pattern of open and filled holes which correspond to the pattern of ink that is to be printed on the tape. The ink is placed on top of the screen, and a rubber squeegee is passed over the top of the screen, forcing the ink into the open holes in the screen. The ink sticks to the surface of the tape, and when the screen is pulled off, a pattern of ink is left on the surface of the tape. The ink should flow somewhat so as to fill in the gaps between adjacent holes, but should not flow so much as to destroy the edge definition of the pattern being printed.
Once these multi-component tapes have been formed they are stacked, laminated, and cut; the binder is removed; and the part is sintered. The stacking process involves careful alignment of the tapes to insure that the features printed on the tapes align in the vertical direction. Lamination is a process of pressing the tapes together at a slightly elevated temperature to weld them into a single body that will not delaminate during sintering. The elevated temperature plastically deforms the binder, which allows the particles to move and create a more intimate contact between the layers. In cases where the tape is too thin to be handled independently, it is left on a carrier until it is laminated to a stack, after which the carrier is peeled off. The stack is built up by laminating one layer at a time. The stack is then cut into individual parts, the polymer binder is removed—usually by heat treatment in a controlled atmosphere—and the parts are sintered.
Finally, after the part is sintered, external interconnections between layers can be added, if necessary. The conductor patterns to be interconnected are designed to intersect the cut edge of the part at a common point. All of the conductors that are exposed on the side of the part at that point can then be interconnected by applying a vertical strip of a conductive material, known as an edge connector, to the side of the part.
The simplest example of using an edge connector is the multi-layer capacitor shown in FIG. 2. In this device, it is desired to connect alternating layers of conductor 27 (separated by intervening layers 28) to the opposite poles of the capacitor. To do this the capacitor is designed as a multi-layer rectangular block 30 with even numbered conductor layers intersecting one end of the block and odd layers intersecting the opposite end (FIG. 2B). After the part is sintered, it is tumbled in an abrasive powder to polish the end of the block, assuring a good contact surface on conductor layers at each end. A conductive ink, frequently referred to as termination compound, is then applied to each end of the block 32. This ink is then dried and sintered in a second heat treatment to form the electrical interconnect between these alternating layers.
In view of the foregoing, a need has been recognized in connection with the provision of single and multiple component particulate tapes that can be produced with one or more of the following characteristics: improved uniformity of particle packing, relatively uniform thickness of multiple component tapes, reduced thickness of the complete tape as well as of individual component layers within a tape, improved lateral resolution of component patterns on and in the tape, and the forming of patterns of components that extend through the thickness of a multi-component tape. | {
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1. Field of the Invention
This invention pertains to an improved system and method of cleansing a filter bed. In particular, this invention relates to automatic backwash filtering systems. More in particular, this invention directs itself to an improved system for cleansing a filter bed utilizing two separate and distinct operations including a backwashing cycle and a purging cycle. Further, this invention pertains to an automatic backwashing filter system which permits substantial utilization of the same fluid flow elements in both a backwashing operation and a purging operation.
2. Prior Art
Automatic backwash filter systems are known in the art as exemplified in U.S. Pat. Nos. 3,239,061 and 4,133,766 assigned to the assignee corporation of this invention concept. However, such automatic backwash filters provide for a singular backwashing operation of the filter beds. It has been found in such prior art systems that there is a possibility that particulate solid contaminants or organisms have been found at the bottom of the filter media bed subsequent to the backwashing operation. In such prior art systems there is a possibility that the particulate material may pass through the filter underdrain and contaminate the filtrate.
Such prior art systems do not purge the filter bed subsequent to the backwashing operation cycle for removal of further contaminants from the filter bed. Thus, in such prior art filtering systems, the safety factor does not provide for a maximization of the filtering of the overall filtering system.
Additionally, where it would be necessary to insert a purge cycle into the prior art filtering systems, such would be complicated by additional hardware and pumping consideration mechanisms which would greatly increase the cost of such prior art systems. Further, the additional hardware and pumping elements would increase the volume considerations of such filtering systems. | {
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The present invention relates to a shoulder rest for use with a violin or a violin-like instrument. More specifically, the invention relates to the type of shoulder rests having a relatively rigid, elongated base and upright clamping elements secured one to each end of the base. The distance between the clamping elements is adjustable to match several sizes of the body of the instrument. The adjustment of the distance between the clamping elements of the shoulder rest is effected by utilizing a row of openings provided in a foot member of at least one clamping element. The row of openings extends along the base. The openings are equidistantly spaced from each other. One or two openings are engaged with a stem-like projection or projections protruding from the top surface of the base. Thus a positive locking of the foot member is achieved, in a number of locations along the base member. In known adjustment mechanisms of this type, the number of positively locked positions is equal to or smaller than the number of the openings in the foot member. The adjacent locked positions are spaced from each other a distance equal to the spacing between adjacent openings.
The above type of adjustability of the shoulder rests has become popular because of simplicity of the structure and adjustment, its security once adjusted, and a number of sizes of violins which can be accommodated by a single shoulder rest.
A typical example of adjustable shoulder rests of this type is described, for instance, in U.S. Pat. No. 5,419,226 (Kun) issued May 30, 1995. A number of openings is provided in a foot member of each of the clamping elements at each end of the base of the shoulder rest. Another, somewhat more complex and expensive, embodiment of this principle is shown in U.S. Pat. No. 3,631,754 (Kun), issued Jan. 4, 1972.
While the adjustability of the above prior art may often be sufficient, there are applications where the spacing between adjacent openings in the foot portion is optimal for manufacture but may be too large to accommodate relatively large differences in the size of violins. This is particularly notable in the area of shoulder rests for small, children's size violins ranging from size 1/16, to 1/4. In such applications, the spacing between adjacent adjustment positions presents too large a percentage of the overall desired clamping distance due to a small size of the violins with the result that, in one position, the clamping force may be too small and in the next position excessive. Also, the length of the foot portion required to provide four adjustment positions is too much for small size violins, where space saving is of the essence.
It is also known to provide a non-positively locked adjustment of the distance between the clamping elements of a violin shoulder rest by a slide-and-setscrew arrangement such as described in U.S. Pat. No. 5,275,078 (Wolf) issued Jan. 4, 1994, where a sleeve with a setscrew receives a sliding arm supporting one of the clamping elements. On adjustment of the distance, the setscrew is tightened to secure the clamping distance. Another arrangement of a non-locked adjustment is described in U.S. Pat. No. 4,333,378 (Hrdlicka), issued Jun. 8, 1982 utilizing a longitudinal slot in the foot member and two threaded stems, projecting from the base and through the slot. Thumbnuts threaded on the stems secure the foot member (and thus the associated clamping element) to the base.
The disadvantage of the non-positively locked arrangement is that it does not provide means which would indicate inadvertent loosening of the setscrew, thumbnuts or other similar fasteners. This may result in diminished tightness of the clamping force with the possibility of accidental release of the shoulder rest from a violin while playing the instrument. The structural complexity is another disadvantage of this type of adjustment mechanism.
It is an object of the present invention to provide an improvement of the first mentioned, positively locked stem-and-opening type of adjustment which would utilize a convenient spacing between the openings in the foot portion of a support of a clamping element while at the same time allowing adjustability in a number of positions which is larger than the number of the openings in the foot portion. | {
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A secure socket layer (SSL) session may be allocated private memory address space and associated with a SSL protocol stack that is independent from other SSL sessions. In a single-core system such as a single-core appliance maintaining a SSL session between a client and a server, the SSL session may be resumed if the SSL session is temporarily disrupted and/or inactive.
A certificate revocation list (CRL) may be used in any cryptographic system, such as a public key infrastructure (PKI) system, for storing information on digital certificates that have been revoked or are no longer valid. A request for connection may include a certificate that has to be validated against a CRL. If information on the certificate matches an entry in the CRL, the request may be refused as the certificate has been identified as revoked. | {
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Natural rubber latex (NRL) is the material of choice in many applications requiring soft, thin-walled elastic articles, such as medical examination and scientific gloves. NRL articles typically are made by dipping a mandrel, pre-coated with a coagulant, into an aqueous rubber emulsion. To produce NRL gloves which are adequately strong, but which do not have pinholes, the dipped NRL gloves must be about 0.18 to about 0.20 mm thick. Although gloves made from NRL possess an excellent combination of flexibility, high elongation at break, tensile strength and a low degree of creep, in recent years the use of NRL has been under attack because of increased instances of allergic reactions caused by proteins and vulcanization accelerator residues present in NRL.
The manufacture of medical exam and scientific gloves from polyurethane is known to those skilled in the art. For example, U.S. Pat. No. 4,463,156, issued to McGary, Jr., et al., discloses a soft, low modulus, non-crystalline segmented polyurethane with a 100% modulus less than about 250 psi, initial tensile set less than about 30% and tensile strength of about 3500 to 6500 psi. McGary, Jr. et al. teach balancing the percent hard segment and the degree of cross-linking within the ranges of 14 to 25% hard segment and 5,000 to 30,000 molecular weight per cross-link in a segmented polyurethane. The polyurethane of the 156 patent is said to produce a flexible glove for use by surgeons and others which is easily donned and comfortable on the hand.
A waterborne dispersion of a polyurethane polymer said to be useful as a film having improved mechanical properties is disclosed by Snow, et al. in U.S. Pat. No. 6,017,997. The film is said to have properties comparable to rubber including, a percentage elongation greater than 700%, a tensile strength greater than 3,500 psi, a 100% modulus below 450 psi, a 300% modulus below 700 psi, and a 500% modulus below 1,500 psi. This film can be prepared in the absence of a solvent, thus making it attractive for a variety of protection products for medical and industrial applications such as gloves, condoms, catheters, and the like. However, the films of Snow et al. are crosslinked by the urethane reaction; therefore, the residual NCO may cause allergic reactions on human skin.
Papalos et al., in U.S. Statutory Invention Registration No. H 1,712, disclose radiation-curable compositions containing monoalkyl or mono-aralkyl ether di-acrylates or di-methacrylates of particular ethoxylated and/or propoxylated polyols. These polyol derivatives substituted with hydrophobic ether functionalities are said to constitute UV-curable diluents that can be isolated in excellent yields with minimal losses during the manufacturing process. The UV-curable diluents of Papalos et al. are said to be useful in radiation-curable compositions.
U.S. Pat. No. 4,876,384 issued to Higbie et al., teaches reactive diluents for radiation curable compositions. The diluents are lower alkyl ether acrylates and methacrylates of particular alkoxylated and non-alkoxylated polyols. Examples are mono-methoxy trimethylolpropane diacrylate, mono-methoxy neopentyl glycol monoacrylate and mono-methoxy, ethoxylated neopentyl glycol monoacrylate having an average of about two moles of ethylene oxide.
No mention is made in either of these disclosures of making a coating, adhesive, sealant or elastomer from the reactive diluent by combining it with an isocyanate to form a polyurethane.
Polyurethane is typically made by reacting a polyol with an isocyanate. The majority of polyoxyalkylene polyether polyols are polymerized through base catalysis. For example, polyoxypropylene dials are prepared by the base-catalyzed oxypropylation of a difunctional initiator such as propylene glycol. During base-catalyzed oxypropylation, a competing rearrangement of propylene oxide to allyl alcohol continually introduces an unsaturated, monofunctional, oxyalkylatable species into the reactor. The oxyalkylation of this monofunctional species yields allyl-terminated polyoxypropylene monols. The rearrangement is discussed in BLOCK AND GRAFT POLYMERIZATION, Vol. 2, Ceresa, Ed., John Wiley & Sons, pp. 17-21. Unsaturation is measured in accordance with ASTM D-2849-69 “Testing Urethane Foam Polyol Raw Materials,” and expressed as milliequivalents of unsaturation per gram of polyol (meq/g). Due to this continual creation of allyl alcohol and its subsequent oxypropylation, the average functionality of the polyol mixture decreases and the molecular weight distribution broadens. Base-catalyzed polyoxyalkylene polyols contain considerable quantities of lower molecular weight, monofunctional species. In polyoxypropylene dials of 4,000 Dalton (Da) molecular weight, the content of monofunctional species may be between 30 and 40 mole percent. In such cases, the average functionality is lowered to 1.6 to 1.7 from the nominal, or theoretical functionality of 2.0. In addition, base-catalyzed polyols have a high polydispersity (Mw/Mn) due to the presence of the substantial, low molecular weight fractions.
Lowering unsaturation and the attendant high monol fraction in polyoxypropylene polyols has been touted as a means of providing polyurethane compositions with improved properties. Often, formulations must be chosen to balance conflicting properties. For example, increases in tensile strength are often accompanied by a decrease in elongation.
Therefore, a need exists in the art for a polyol that will provide prepolymers that can be used to make thin films having the desired properties of natural rubber latex (NRL) including low modulus, high elongation, high tensile strength and solvent resistance, without the drawbacks associated with NRL such as allergic reactions. Further, it would be desirable if the polyol could provide UV-curable polyurethane compositions having a low modulus, high elongation, high tensile strength and solvent resistance that are suitable for use in or as coatings, adhesives, sealants, elastomers and the like. | {
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I. The Characteristics of Sleep Apnea
First described in 1965, sleep apnea is a breathing disorder characterized by brief interruptions (10 seconds or more) of breathing during sleep. Sleep apnea is a common but serious, potentially life-threatening condition, affecting as many as 18 million Americans.
There are two types of sleep apnea: central and obstructive. Central sleep apnea, which is relatively rare, occurs when the brain fails to send the appropriate signal to the breathing muscles to initiate respirations, e.g., as a result of brain stem injury or damage. Mechanical ventilation is the only treatment available to ensure continued breathing.
Obstructive sleep apnea (OSA) is far more common. It is one of the several entities that make up the broader group of sleep disordered breathing (SDB). This group of disorders ranges from habitual snoring to OSA. Normally, the muscles of the upper part of the throat keep the airway open to permit air flow into the lungs. When the muscles of the upper airway relax and sag, the relaxed tissues may vibrate as air flows past the tissues during breathing, resulting in snoring. Snoring affects about half of men and 25 percent of women—most of whom are age 50 or older.
In more serious cases, the airway becomes blocked, making breathing labored and noisy, or even stopping it altogether. In a given night, the number of involuntary breathing pauses or “apneic events” can be quite frequent. These breathing pauses are almost always accompanied by snoring between apnea episodes, although not everyone who snores has OSA.
Lack of air intake into the lungs results in lower levels of oxygen and increased levels of carbon dioxide in the blood. The altered levels of oxygen and carbon dioxide alert the brain to resume breathing and cause arousal. The frequent interruptions of deep, restorative sleep often lead to early morning headaches, excessive daytime sleepiness, depression, irritability, and learning and memory difficulties.
The medical community has become aware of the increased incidence of heart attacks, hypertension and strokes in people with moderate or severe obstructive sleep apnea. It is estimated that up to 50 percent of sleep apnea patients have high blood pressure.
Upon an apneic event, the sleeping person is unable to continue normal respiratory function and the level of oxygen saturation in the blood is reduced. The brain will sense the condition and cause the sleeper to struggle and gasp for air. Breathing will then resume, often followed by continued apneic events. There are potentially damaging effects to the heart and blood vessels due to abrupt compensatory swings in blood pressure. Upon each event, the sleeping person will be partially aroused from sleep, resulting in a greatly reduced quality of sleep and associated daytime fatigue.
Although some apneic events are normal in all humans, the frequency of blockages will determine the seriousness of the disease and opportunity for health damage. When the incidence of blockage is frequent, corrective action should be taken.
II. Sleep and the Anatomy of the Upper Airway
As FIGS. 1A and 1B show, the upper airway consists of a conduit that begins at the nasal valve, situated in the tip of the nose, and extends to the larynx. Although all tissue along this conduit is dynamic and responsive to the respiratory cycle, only the pharyngeal conduit structures—the tissues in the region of the airway that starts behind the nasal cavity and ends in its connections to the supraglottic larynx—is totally collapsible. The pharyngeal structures and individual anatomic components within this region include the pharyngeal walls; the base of the tongue; the vallecula; the hyoid bone and its attachments; the soft palate with uvula, the palatine tonsils with associated pillar tissue; and the epiglottis.
The cross sectional area of the upper airway varies with the phases of the respiratory cycle. At the initiation of inspiration (Phase I), the airway begins to dilate and then to remain relatively constant through the remainder of inspiration (Phase II). At the onset of expiration (Phase III) the airway begins to enlarge, reaching maximum diameter and then diminishing in size so that at the end of expiration (Phase IV), it is at its narrowest, corresponding to the time when the upper airway dilator muscles are least active, and positive intraluminal pressure is lowest. The upper airway, therefore, has the greatest potential for collapse and closure at end-expiration. Schwab R J, Goldberg A N. Upper Airway Assessment: Radiographic and other Imaging Techniques. Otolaryngol Clin North Am 1998; 31:931-968.
Sleep is characterized by a reduction in upper airway dilator muscle activity. For the individual with obstructive sleep apnea (OSA) and perhaps the other disorders which comprise much of the group of entities called obstructive sleep-disordered breathing (SDB), it is believed that this change in muscle function causes pharyngeal narrowing and collapse. Two possible etiologies for this phenomenon in OSA patients have been theorized. One is that these individuals reduce the airway dilator muscle tone more than non-apneics during sleep (the neural theory). The other is that all individuals experience the same reduction in dilator activity in sleep, but that the apneic has a pharynx that is structurally less stable (the anatomic theory). Both theories may in fact be contributors to OSA, but current studies seem to support that OSA patients have an intrinsically structurally narrowed and more collapsible pharynx. Isono S. Remmers J, Tanaka A Sho Y, Sato J, Nishino T. Anatomy of Pharynx in Patients with Obstructive Sleep Apnea and in Normal Subjects. J Appl Physiol 1997: 82:1319-1326.
Although anatomic closure is often accentuated at specific sites, such as the velopharyngeal level [Isono, Ibid], studies of closing pressures [Isono, Ibid] supports dynamic fast MRI imaging that shows narrowing and collapse usually occurs along the entire length of the pharynx. Shellock F G, Schatz C J, Julien P, Silverman J M, Steinberg F, Foo T K F, Hopp M L, Westbrook P R. Occlusion and Narrowing of the Pharyngeal Airway in Obstructive Sleep Apnea: Evaluation by Ultrafast Spoiled GRASS MR Imaging. Am J of Roentgenology 1992:158:1019-1024.
III. Prior Treatment Modalities
To date, the only modality that addresses collapse along the entire upper airway is mechanical positive pressure breathing devices, such as continuous positive airway pressure (CPAP) machines. All other modalities, such as various surgical procedures and oral appliances, by their nature, address specific sectors of the airway (such as palate, tongue base and hyoid-vallecula levels), but leave portions of pharyngeal wall untreated. This may account for the considerably higher success rate of CPAP over surgery and appliances in controlling OSA. Although CPAP, which in essence acts as an airway splint for the respiratory cycle, is highly successful, it has some very significant shortcomings. It can be cumbersome to wear and travel with, difficult to accept on a social level, and not tolerated by many (for reasons such as claustrophobia, facial and nasal mask pressure sores, airway irritation). These factors have lead to a relatively poor long-term compliance rate. One study has shown that 65% of patients abandon their CPAP treatment in 6 months.
The need remains for simple, cost-effective devices, systems, and methods for reducing or preventing sleep disordered breathing events. | {
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1. Field of the Invention
The present invention relates to a display apparatus and a manufacturing method thereof. More particularly, the present invention relates to a display apparatus having substantially reduced power consumption and improved display quality, and a method of manufacturing the same.
2. Description of the Related Art
A display apparatus, such as a liquid crystal display (“LCD”) device or an organic electroluminescence (“EL”) display device, for example, typically includes a thin film transistor (“TFT”) array panel, which is used as a circuit panel for driving pixels of the display apparatus. The TFT array panel includes a scanning signal line or wire (e.g., a gate line or wire), which transmits scanning signals, and a data line or wire, which transmits data signals. The TFT array panel further includes TFTs connected to the gate wire and the data wire and pixel electrodes connected to the TFTs. Additionally, a gate insulating layer is disposed on the gate wire to insulate the gate wire, and a passivation layer is disposed on the TFTs and the data wire to insulate the TFTs and the data wire. Each of the TFTs includes a gate electrode, which is a portion of the gate wire, a semiconductor layer, which forms a channel of the TFT, a source electrode, which is a portion of the data wire, and a drain electrode, which is connected to the pixel electrode and transmits a data signal to the pixel electrode from the data wire via the TFT. The TFTs, generally speaking, are switching elements that transmit the data signals to the pixel electrodes from the data wire in response to the scanning signals received from the gate wire.
The TFT array panel typically further includes storage electrode lines, to which a common voltage signal is applied. However, operation of the display apparatus is adversely affected due to delay of the common voltage signal caused by electrical resistance of the storage electrode lines.
Thus, there is a need for a TFT array panel having storage electrode lines with reduced electrical resistance. | {
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1. Field of the Invention
This invention relates to the field of mechanical connectors, and in particular to connector assemblies for stage separation systems, such as satellite and missile systems.
2. Description of Related Art
Transport systems, such as rockets that transport satellites into space, vessels that transport submerged sections of ocean structures such as oil platforms, and the like, require a means for securely fastening different items together for transport, and reliably and easily unfastening the items for deployment. Multi-stage rockets also require a means for fastening the stages together, and reliably unfastening the stages as each stage is spent. In other situations, such as aircraft carrier based aircraft, the items are transported or stored in a disassembled state and require a means for rapidly fastening the items for deployment, and reliably and easily unfastening the items for subsequent storage or transport.
A variety of devices have been developed to secure two items together while also allowing the items to be separated quickly and reliably. In the aerospace industry, the common connection devices include bolts and bands that can be severed. Bolts are used to fasten the two items together, and an explosive charge is typically used to sever the bolts at the proper time, thereby unfastening the two items. Depending upon the application, ancillary devices such as springs may be used to urge the two items apart when the bolts are severed. To assure a reliable separation, the number of bolts used to fasten the two items is kept to a minimum; this results in load points at the bolts far in excess of the load imposed by a distributed fastening system.
Belt structures are commonly used to provide for a distributed load. A belt structure that is commonly employed to fasten items together is a xe2x80x9cV-bandxe2x80x9d, typified by U.S. Pat. No. 4,715,565, incorporated by reference herein. The V-band includes a tension belt for securing a plurality of retainers against camming surfaces on flange members on separable spacecraft component parts. A typical V-band embodiment consists of an upper ring attached to the payload, a lower ring attached to the launch vehicle, and a clampband that is circumferentially tensioned to the flanges of the upper and lower rings, as illustrated in FIG. 1. The upper ring 101 and lower ring 102 each have flanges that, when joined, form a xe2x80x9cVxe2x80x9d shaped projection 150A. The clampband consists of a belt 110 and a plurality of clamps 120. Each of the clamps 120 has a recess 150B corresponding to the shape of the projection 150A of the upper 101 and lower 102 rings. When the belt 110 is tensioned, the recesses 150B of the clamps 120 are compressed against the projections 150A, thereby securing the upper 101 and lower 102 rings together.
The belt 110 is conventionally tensioned by bolts (not shown) that are in line with the belt 110, and explosive bolt cutters are used to sever the bolts to release the tension. When the tension in the belt 110 is released, the clamps 120 are free to separate from the projection 150A, thereby decoupling the upper 101 and lower 102 rings. The conventional V band structure also includes means, such as springs, for urging the clamps 120 apart from the projection 150A, to provide for a reliable separation. Means are also provided to retain the belt 110 and clamps 120 after separation, to minimize the occurrence of xe2x80x9cspace junkxe2x80x9d.
For V-bands to work properly, the tension required in the tensioning belt 110 is relatively high (about 3800 pounds for a 38 inch diameter; 6800 pounds for a 66 inch diameter). This high tension requires radial stiffeners in the rings 101, 102. The sudden release of this stored energy generates high shock, and imposes additional requirements on the means used to retain the fast moving belt and clamps after separation. Because of the high tension requirements, the combined weight of the belt, clamps, and ancillary required devices is substantial (as much as 25 pounds for a 38 inch diameter V-band structure). The high tension requirements of V-bands often require specialized tools and instruments to tension the band. The high tension and high release shock effects also limits the reliable life of the components, thereby limiting the amount of testing that can be applied to the components that are actually flown.
Another structure that is commonly used to provide for an easily separable connection is an explosive frangible joint, as typified by U.S. Pat. Nos. 4,685,376 and 5,390,606. An explosive detonating cord is placed within a contained space that forms the frangible joint between the two items. Separation is achieved by detonating the cord within the contained space, forcing a rapid crack propagation through the frangible joint. Although the weight of an explosive frangible joint is less than that of an equivalent sized V-band, it is still substantial (as much as 17 pounds for a 38 inch diameter joint). The destructive nature of this separation system precludes testing of the joints that are actually flown.
Each of the aforementioned separation connectors also imparts a substantial shock to the connected items upon separation, and the explosive nature of the devices used for separation introduce a risk of personal injury, particularly during pre-launch assembly and testing. Because of the shock effects, such separation connectors are not commonly used on items that are routinely disassembled for storage or transport.
It is an object of this invention to provide a separation connector that is light weight. It is a further object of this invention to provide a separation connector that allows for repeated testing. It is a further object of this invention to provide a separation connector that allows for separation with minimal shock effects. It is a further object of this invention to provide a method for connecting components that is simple, secure, and reliable. It is a further object of this invention to provide a connector component that is stiff, strong, and easy to use.
These objects and others are achieved by a separation connector that comprises a plurality of leaves with leaf lips that are secured within a mating surface by a tensioned band in one embodiment, and a compression band in another embodiment. The leaves and mating surface are designed such that the tension or compression required on the band is significantly less than the tension required on a V-band. A shear structure is also provided that minimizes translation of the leaves with respect to mating surface. In a preferred embodiment, the tensioned band is detensioned by a thermal device that melts, decomposes, or severs the band, and the compressed band is decompressed by a contraction or removal of an expansion element. When the band is detensioned or decompressed, springs urge the leaves away from the mating surface, thereby allowing for the separation of the connected items. Preferably, the leaves are hinged, allowing for ease of coupling and decoupling to the mating surface. Multiple sections of leaf elements can be employed to form a perimeter structure corresponding to the structure of the mating surface. | {
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It is known that the aerodynamic configuration of an aircraft corresponds to a particular combination of positions of mobile members of an aircraft, such as the landing gear or aerodynamic surfaces arranged on the wings (flaps, ailerons, spoilers, . . . ), the aerodynamic characteristics of the aircraft depend upon. From document WO-2007/074173, means for monitoring landing flaps of a wing profile of an aircraft are known, and from document FR-2899405, means for automatically controlling spoilers are known.
Usually, when designing the aerodynamic configurations of an aircraft, for takeoff phase, the aim is to achieve maximum fineness, that is the maximum ratio of airlift to drag, in order to provide the aircraft with good lifting performance.
The drawback of such a design is that it is required to select a priori the parameter, in this case fineness, which is aimed to be optimised. Such selection does not make it possible to ensure optimum operation in all phases. In particular, optimising fineness can result in: a non-maximum airlift at the trim of the minimum takeoff speed VMU, because fineness is a compromise between airlift and drag; and a higher drag of the aircraft at zero trim, when the aircraft is in the rolling phase before turning and taking off. | {
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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.
Mains electricity is a type of electric power supply. A mains voltage signal is distributed and used to power various systems and devices that require power, e.g., lighting devices, portable appliances, and networked nodes including multimedia home networking nodes. A mains voltage signal is also commonly referred to as a line voltage or as a domestic mains signal.
A zero crossing detector, which detects zero crossing points of the mains voltage signal, is typically used to synchronize other voltage signals with the mains voltage signal. This synchronization of the mains voltage allows for synchronized communications among and/or between the circuits in a network. | {
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1. Field of the Invention
The present invention relates to an apparatus for automatically starting up a nuclear reactor and more particularly to an apparatus for automatically manipulating a nuclear reactor until the temperature and the pressure reach the predetermined levels after the reactor has reached a critical state.
2. Description of the Prior Art
There are three essential steps in the starting-up operation of a nuclear reactor: critical manipulation, heat-up and pressurization manipulation, and power-up manipulation. These steps are performed in the order mentioned. The critical manipulation is defined as a step of gradually withdrawing the control rods when the reactor is in the resting state, until the reactivity .rho. of the reactor becomes unity. The reactivity of 1 means that the reactor is at the critical condition where nuclear fission in the reactor proceeds continuously and that the neutron flux to cause the following nuclear fission is constant. Namely, the reactor is said to be critical, subcritical and supercritical, respectively, when the reactivity is equal to, less and more than unity. Whereas the nuclear fission attenuates in the subcritical condition (.rho.<1), the fission proceeds indefinitely in the supercritical condition (.rho.>1) and the reactor may run away unless any safety control is performed. The critical manipulation is, in other words, to cause the nuclear reaction in the reactor to proceed from the nuclear resting state (where even if neutron flux is generated the resultant nuclear fission attenuates) to a state where the reactivity .rho. is 1 or slightly larger than 1, i.e. around 1.01, by gradually withdrawing the control rods.
Whether the reactor has got critical or not, is judged by checking the reactor period. The reactor period, expressed by the reciprocal 1/(dn/dt) of the rate dn/dt of change in the neutron flux n in the reactor with time t, is defined as the mean time required for the power level of the reactor to change by the factor e = 2.71828. The dimension of the reactor period is time. Namely, the period is infinite for the reactivity of 1, i.e. critical state, a negative finite value for the subcritical value, and a positive finite value for the supercritical state. The state of the reactor being critical can be identified by the fact that the reactor period assumes a positive value and the time during which the neutron flux is at a certain value lasts longer than, for example, a predetermined period. In such a critical state, the reactor thermal power is less than about 1% of the rated power.
After the reactor has become critical, the control rods are further withdrawn, while the level of the reactor water is kept constant, to subject the reactor to heat-up and pressurization. During this heat-up and pressurization process, the reactor is separated from a turbine and the like so that the supply of water into the reactor and the derivation of the steam are not normally carried out. Exceptionally, however, the decrement of a reactor water level caused by a reactor water purifying system is compensated by a water supply system, and some fractional quantity of the steam is taken out after the later stage of the heat-up and pressurization process, for the warming-up of the turbine.
The present invention provides an apparatus for automatically performing the manipulation of a reactor for heat-up and pressurization after the completion of the critical manipulation. For this purpose, the following problems must be solved.
First, for the heat-up and pressurization, the operator manually withdraws the control rods by monitoring various controlled variables so that the burden imposed on him is severe and the time required for manipulation widely varies depending upon the skill of operator. Secondly, it is specifically necessary in this stage to keep constant the heat-up ratio of the temperature in the reactor so as not to expose the pressure vessel to thermal impact. Thirdly, the reactivity in the heat-up and pressurization process is derived by summing the positive reactivity effect due to the withdrawal of the control rods and the negative reactivity effect due to the temperature in the reactor, but since the temperature varies, it is necessary for keeping the heat-up ratio constant to control the withdrawal of the control rods so as to compensate for the variation. Fourthly, since the negative reactivity effect varies non-linearly with the temperature in the reactor, it is difficult to compensate for the reactivity effect. Fifthly, the response to the variation of the reactor temperature caused due to the withdrawal of the control rods, is slow. Sixthly, since the pressure in the boiling water reactor has an influence on the reactor temperature, the reactivity should be corrected with respect to pressure.
The reactor thermal power now after the completion of the heat-up and pressurization manipulation is about 10% of the rated power and thereafter the steam is conducted to the turbine to increase the speed thereof while the power-up manipulation is performed by controlling the control rods and the recirculation flow.
The term "reactor temperature" used in this specification refers to the temperature of the water serving as coolant and moderator in the reactor or of the wall of the pressure vessel. Although in the start-up operation of a reactor the heat-up ratio of the temperature of the reactor water must be actually kept constant, it is difficult to measure the temperature exactly. Instead, the temperature at the wall of the pressure vessel may be conveniently used as the measure of the heat-up ratio. Accordingly, in this specification, the reactor temperature thus defined is used to represent the temperature of each portion useful to monitor the heat-up ratio of the reactor. | {
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Patent Document 1 describes an automatic terminal insertion machine in which electric wires chucked by a terminal insertion head and lifted from a clamp rod are caught one by one and the terminals thereof are inserted into predetermined terminal accommodation chambers of connector housings placed being positioned on a mount.
Moreover, Patent Document 2 describes a terminal insertion device that inserts the terminal of a terminal with an electric wire into a terminal accommodation chamber of a connector housing in a manufacturing line of a wire harness or the like.
Moreover, a technology usable for automating the terminal insertion work or the like is disclosed, for example, in Patent Document 3 and Patent Document 4. That is, Patent Document 3 describes a method of measuring a position shift or the like by using a camera provided on the terminal insertion head. Moreover, Patent Document 4 describes a component position measurement method capable of accurately recognizing the position of the leading end of a component. | {
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In recent years, AC-type plasma display devices (AC-PDPs) have been rapidly widespread due to their large screen and slimness compared with conventional cathode-ray-tube televisions and others. However, due to the large screen, its high power consumption and cost becomes problematic.
The display panel of the AC-PDP has X electrodes and Y electrodes alternately arranged approximately in parallel to one another and also has address electrodes crossing in a direction perpendicular to these electrodes to form a two-dimensional matrix.
FIG. 32 is a conceptual drawing of the cell structure of the display panel. A front glass 10a and a rear glass 10f are separated by ribs, and discharge gas, such as Xe, is enclosed in a discharge space 10 therebetween. A Y electrode 9Y and an X electrode 9X are formed in the front glass 10a, and a dielectric layer 10b for insulating from the discharge space 10 is formed thereon. Further, an MgO (magnesium oxide) protective layer 10c is formed thereon.
On the other hand, an address electrode 9A is formed on the rear glass 10f, and a dielectric layer 10e for insulating from the discharge space 10 is formed thereon. Further, a phosphorous layer 10d is formed thereon.
Drive of the plasma display panel can be divided into a reset period of resetting charges accumulated in the cell, an address period of selecting a light-emission position of the panel, and a sustain period of emitting light from the panel and controlling brightness. In the address period, a voltage is applied between the address electrode 9A and the Y electrode 9Y for discharge so that wall charges are added to the cell, whereby, a cell for light emission in the next sustain period can be selected.
Next, the operation in the sustain period for light emission of the plasma display panel is described. When a voltage is applied to the Y electrode 9Y and the X electrode 9X, a voltage is applied to the discharge space 10. When the voltage becomes equal to or larger than a discharge voltage, light emission occurs. That is, in terms of an electric circuit, a switch 9c is turned ON and a discharged state occurs. When this discharge stops, light emission also stops. To repeat light emission, a voltage is required to be applied to the X and Y electrodes of the panel alternately.
FIG. 33 shows changes with time regarding voltages to be applied to the X and Y electrodes of the panel and currents flowing through the panel. The operation for light emission by applying a voltage to a Y side is described below. The same goes for the case where a voltage is applied to an X side for light emission. First, during a period a, an XY wiring capacitance of the panel corresponding to 9d of FIG. 32 is charged to increase a voltage to be applied to the cell. At this time, a charge current flows through the panel. When the voltage to be applied to the cell becomes higher than a firing voltage, the cell emits light, and a gas-discharge current with light emission flows during a period b. At this time, due to an inductance of the wiring, a resistance of a switch element, and other factors, the panel voltage is decreased by ΔV. Next, the panel voltage is decreased in a period c. At this time, a discharge current flows through the panel. This operation of applying a voltage alternately to the X and Y electrodes of the panel for light emission is repeated at a high speed of several ten to several hundred kHz.
FIGS. 34A and 34B show main driving circuits and their operations for achieving the above-described operation. First, a bi-directional switch element 402y is turned ON to charge the XY wiring capacitance of the panel via a coil 5y. This corresponds to the period a in FIG. 33, and a current flows through a path indicated by the charge current shown in FIG. 34A. After the voltage of a Y-side electrode 6y of the panel is increased to a predetermined voltage, when a switch element 1y (hereinafter referred to as a clamp element) is turned ON to clamp the panel voltage at a power-supply voltage Vs, the voltage applied to the cell becomes equal to or larger than the discharge voltage, thereby emitting light. This corresponds to the period b in FIG. 33, and a current flows through a path indicated by the gas-discharge current causing light emission in FIG. 34B. Next, the bi-directional switch element 402y is turned ON to discharge the XY wiring capacitance of the panel via the coil 5y. This corresponds to the period c in FIG. 33, and a current flows through a path indicated by the discharge current in FIG. 34A.
Charging and discharging of the XY wiring capacitance of the panel is performed via the coil because the panel voltage is increased and decreased by using a resonant operation of the XY wiring capacitance and the coil of the panel, thereby reducing a loss in the XY wiring capacitance of the panel at the time of charging and discharging.
In the above-described operation, due to the charge current, the gas-discharge current causing light emission, and the discharge current passing through the switch elements, a loss occurs in each switch element. Such a loss is a cause of increasing power consumption of the plasma display device. Moreover, since a driving circuit is required on both X and Y sides of the panel, the number of components is increased. Such an increase is a cause of increasing cost.
To solve the problems in achieving a low loss of the driving circuit and a reduction in the number of components, driving circuits shown in FIGS. 35 and 37 have been suggested.
FIG. 35 shows a driving circuit of a plasma display device disclosed in Japanese Patent Application Laid-Open Publication No. 2000-330514 (Patent document 1). The driving circuit has a feature in which as a switch element, an Insulated Gate Bipolar Transistor (IGBT) is used in place of a conventional power MOSFET. Unlike the power MOSFET, in the IGBT, conductivity modulation occurs in the element. Therefore, the resistance is small, thereby reducing a loss in the driving circuit.
Here, in FIG. 35, only one driving circuit of the panel is shown, and the other one is fixed to the ground, but the driving circuit side fixed to the ground is considered to be omitted. The reason is that the amplitude of the shown driving circuit is based on a power-supply voltage from the ground, and therefore the voltage applied between X and Y of the panel cannot be changed to be positive or negative. Thus, as the AC-PCP, light emission cannot be repeated. For this reason, the driving circuits suggested in Japanese Patent Application Laid-Open Publication No. 2000-330514 are considered to be as shown in FIG. 36.
However, unlike the power MOSFET, a general IGBT does not incorporate a diode. Therefore, as shown in FIG. 36, when a discharge current flows at one driving circuit, a diode has to be added in inverse-parallel in order to pass a current from an emitter to a collector of an IGBT of the other circuit. For this reason, there are problems of increasing a number of components, complexing circuitry and assembling process, and becoming high cost.
FIG. 37 shows a driving method published in “New Two Stage Recovery (TSR) Driving Method for Low Cost AC Plasma Display Panel”, IDW (International Display Workshops) '05. In this driving method, either one of an X side or a Y side of the panel is fixed to the ground, and positive and negative voltages are alternately applied to the other side, thereby sustaining light emission. This driving method is hereinafter referred to as a half-bridge driving method. By contrast, a method used in the circuitry in FIGS. 34A and 34B is referred to as a full-bridge driving method.
In the half-bridge driving method, unlike the full-bridge driving method, a driving circuit on one side can be omitted, therefore, significantly reducing the number of component is achieved. Furthermore, in FIGS. 34A and 34B, at the time of passing a gas-discharge current with light emission, a charge current, and a discharge current, a voltage drop occurs at switch elements at both of the X and Y sides in the full-bridge driving method. By contrast, advantageously, in the half-bridge driving method, a voltage drop occurs only at the switch element on one side. However, in the half-bridge driving method of FIG. 37, a power MOSFET is used as a switch element, and the present inventors have found through studies that there are problems as described below.
FIG. 38 shows panel driving waveforms in the half-bridge driving method disclosed in the above-described publication. In an AC-PDP, as described above, positive and negative voltages are alternately applied between X and Y of the panel, thereby repeating light emission. Therefore, in the half-bridge driving method in which one side of the panel is fixed to the ground, positive and negative voltages ±Vs are required to be applied to the other side of the panel to drive the panel. In the full-bridge driving method, voltages to be output from the driving circuit are from 0V to Vs, the breakdown voltage of the switch element in the half-bridge driving method is disadvantageously doubled compared with the full-bridge driving method.
Vs of the AC-PDP is on the order of 200V. In the full-bridge driving method, as a switch element, a power MOSFET with a breakdown voltage on the order of 300V is used. Therefore, the power MOSFET for use in the half-bridge driving method is required to have a breakdown voltage on the order of 600V.
Output characteristics of these power MOSFET are shown in FIG. 39. From these results, it can be found that a resistance of one 600V power MOSFET is larger than a resistance of two 300V power MOSFET in series with a full-bridge driving method. This is because the resistance of the power MOSFET is increased in proportion to 2.5-th power of the breakdown voltage.
For this reason, in the half-bridge driving method using the power MOSFET of FIG. 37, there has been a problem that a loss of the driving circuit is disadvantageously increased compared with the full-bridge driving method using the power MOSFET. | {
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In environments that experience prolonged freezing temperatures (below 32 degrees Fahrenheit), build up of ice can be problematic. For example, some containers may become filled with ice over time, which may require removal for a desired use of the container. In some instances, ice can removed using additives, like salt, which lowers the freezing point of water and causes ice to melt in some conditions. However, use of additives has some drawbacks. Additives usually take a considerable amount of time to melt ice and leave a sometimes undesirable waste product (e.g., the salt), which may cause damage by excessive buildup and/or by accelerating corrosion of some materials like metal.
Ice can also be melted by applying a heating device, such as a heated coil to the ice. For example, heated coils may be placed in a container that is filled with ice or the heated coils may be integrally formed with the container and activated to heat the container, and thus prevent build up of ice or to melt existing ice. Often, electricity is applied to the coils to create the heat, which may then melt ice that is in the container. Some coils may use transfer heat from hot water to the ice and operate as a radiator. However, use of a heating device also has drawbacks. Applying heat can take a considerable amount of time depending on the way the heat is applied. When heat is generated from electricity, use of heat may expose a user to electrical shock. Heating devices can be expensive, especially when they are dedicated to a single location, such as when they are integrated in a container since each container would then have a dedicated heating device. Finally, use of heating devices may be impractical in many situations, such as when a heating device cannot be easily installed in a specific space. | {
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Achieving goals of a user may be based on a number of applications and/or devices that operate independently from each other. However, these disparate applications and/or devices may all contribute to related goals of a user. Typically, a user is required to take information from these applications and/or devices in order to determine what goals a user would like to accomplish and how the user is achieving the user goals. As such, there is a need to improve how a user determines goals in which the user is interested and how to monitor and control the applications and/or devices in order to reach the goals. | {
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This invention relates to the field of door security systems. More specifically, this invention relates to an electric strike for securing a door to a door frame.
Electric strikes for securing hinged or swinging doors are well-known in the field of door security systems. The electric strikes are employed with doors having projectable dead bolts or latch bolts that engage the electric strike. The electric strike can be configured to secure the door alone, or in combination with other conventional security systems. The electric strike typically is mounted to the door frame and defines an opening in the jamb face of the door frame for receiving the latch bolt and/or dead bolt from the lock set mounted to the door. The electric strike further defines an opening in the frame face contiguous with the opening in the jamb face of the door frame. A pivotal keeper on the electric strike selectively closes the opening in the frame face. A bolt, projecting from the edge of the door, engages the electric strike through the opening in the jamb face. Actuation of the electric strike unlocks the keeper. The keeper is then pivotable to uncover or open the frame face opening to allow the bolt to swing therethrough, and thereby allow opening of the door. The keeper is pivoted by the door being pushed, whereby the bolt engages the keeper of the strike.
The lock assembly of a conventional electric strike is commonly operated by a solenoid. The solenoid is typically configured to be spring biased, wherein energization of the solenoid overcomes the biasing force of the spring to either lock or unlock the electric strike. In a first configuration, power must be continuously supplied to the solenoid in order to maintain the electric strike in a locked condition. This configuration requires a relatively high and continuous input of energy and therefore typically requires electrical wiring through the doorway from an electric line source.
Similarly, electric strikes configured to unlock upon energization can also require a continuous supply of energy in order to maintain the lock in an unlocked condition. Therefore, particularly in settings where the door is to remain unlocked for a substantial period of time, such as during a conventional work day, electrical energy must nevertheless be continuously provided to the electric strike. This second configuration also therefore requires interconnection to continuous line current through the door frame. | {
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1. Field of the Invention
The present invention relates to a flame retardant resin composition, a method for production thereof, and a molded article thereof, and particularly to a flame retardant resin composition comprising a cellulose resin, a method for production thereof, and a molded article thereof.
2. Description of the Related Art
Conventionally, petroleum resins such as a polyethylene resin, a polypropylene resin, vinyl chloride, polyamide, a polystyrene resin, and a PET (polyethylene terephthalate) resin, are widely used as a melt molding material including a material for injection molding and a material for extrusion.
Waste of daily necessaries and industrial products made from petroleum resins is recycled in part, but most of the waste is disposed by incineration, landfill and the like. Accordingly, cellulose resins attract attention as biomass resins to deal with global environmental problems such as global warming and running out of oil.
The cellulose resins are expected to be used for various purposes such as electrical and electronic equipment components, and materials for housing. When a resin composition comprising a cellulose resin is used for an exterior material of office automation equipment such as televisions and personal computers, the resin composition comprising a cellulose resin requires flame retardance, mechanical characteristics, and moldability.
Generally, in order for a resin as a polymer material to obtain flame retardance, a flame retardant is added to the polymer material. Representative examples of flame retardants include a halogen flame retardant, a phosphorous flame retardant, and an inorganic particle flame retardant. However, the halogen flame retardant has many problems on the environment such as the generation of halogen gas and black smoke at the time of combustion, and the generation of dioxin at the time of incineration. Furthermore, the phosphorous flame retardant has problems on the environment such as the generation of phosphine gas, and in addition, it has problems such as high prices and concerns about supplying mineral phosphate as a raw material.
On the other hand, magnesium hydroxide particles which are one of metal hydroxides representing inorganic particle flame retardants are harmless and have few problems on the environment. Furthermore, the magnesium hydroxide particles are inexpensive and can be derived from abundant raw material resources so that individual problems occurring in the halogen flame retardant or in the phosphorous flame retardant can be eliminated.
For a flame retardant comprising magnesium hydroxide particles, Japanese Patent Application Laid-Open No. 2007-119508 discloses the magnesium hydroxide particles which have a high flame retardance and a small amount of emission of carbon monoxide and smoke by including a transition metal compound at 100 to 1,000 ppm.
Japanese Patent Application Laid-Open No. 2000-086858 discloses a flame-retardant abrasion-resistant resin composition comprising a propylene-ethylene block copolymer, an ethylene-vinyl acetate copolymer, and a metal hydroxide represented by magnesium hydroxide, and further comprising a silane coupling agent having amino groups.
Japanese Patent Application Laid-Open No. 10-204298 discloses a flame retardant thermoplastic resin composition comprising a thermoplastic resin, a halogen flame retardant, a flame retardant agent, silicone, and magnesium hydroxide having particles with a particle diameter of 0.2 μm to 6 μm.
Japanese Patent Application Laid-Open No. 2006-232980 discloses a method for producing surface-coated flame retardant particles, comprising the steps of preparing a dispersion liquid of flame retardant particles with a particle diameter of 1 nm to 500 nm including magnesium hydrate in an aqueous solution in which metal salts of organic compounds and a dispersant are dissolved, and adding dropwise an acid aqueous solution into the dispersion liquid and depositing organic compounds on the surface of the flame retardant particles to form a coating layer. | {
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In a communication network, such as a cellular communication network, local parameter settings of one communication node oftentimes influence the selection of local parameters of neighboring communication nodes in the communication network. For instance, it is sometimes necessary for each base station in a cellular communication network to select a set of parameters that is uniquely distinguishable from those selected by its neighboring base stations (i.e., base stations that serve neighboring cells in the cellular communication network). Take downlink transmission for example, each base station needs to transmit a locally unique Reference Signal (RS) for User Equipments (UEs) to identify the base station and to synchronize to the downlink transmission from the base station. The set of available reference signals is limited, and each base station needs to select (or be assigned) a reference signal that is different from the reference signals of its neighboring base stations. As another example, each base station may select (or be assigned) one of several frequency bands for transmission. If the same frequency band is only reused by other base stations serving cells that are far away, inter-cell interference can be significantly reduced. This is the classical frequency planning commonly practiced in second generation networks such as Global System for Mobile Communications (GSM) networks. There are also occasions when each base station may need to set a value to a parameter, such as transmit power, in such a way that the setting is compatible with those of the neighboring base stations in order to achieve a certain notion of optimality of the entire cellular communication network. These are just some typical problems encountered in the design of a cellular communication network in which a local parameter setting influences and is influenced by the settings of the neighboring cells.
Some of these problems, such as RS and frequency reuse, are typically static in nature and can therefore be solved by advanced planning during the build out of the cellular communication network. Currently, the parameters are set by planning tools that have access to information such as base station locations and radio propagation characteristics. Once a solution that is optimal network-wise is found, it remains unchanged for a long time until the deployment changes. However, other problems, such as transmit power control, are more dynamic in nature and require more frequent updates as the channel conditions vary. Methods that allow base stations to dynamically adjust their choice of parameters are therefore quite desirable.
Recently, there have been new applications in which the setting of conventional long-term parameters, such as frequency and RS reuse, also needs to adapt to short term changes and there is no central controller to oversee the update of the parameters. For example, in device-to-device communication, the UE locations change over time. Moreover, arrival and departure of devices also alter the system topology, and thus neighboring relationships, dynamically at a very fast pace. If the same RS selection or frequency reuse setting is to be performed in such distributed network, a distributed mechanism must be employed.
As such, there is a need for systems and methods for distributed parameter coordination in a communication network, such as a cellular communication network. | {
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1. Technical Field
The present invention relates generally to a data compression and decompression and, more particularly, to systems and methods for providing content independent lossless data compression and decompression.
2. Description of the Related Art
Information may be represented in a variety of manners. Discrete information such as text and numbers are easily represented in digital data. This type of data representation is known as symbolic digital data. Symbolic digital data is thus an absolute representation of data such as a letter, figure, character, mark, machine code, or drawing,
Continuous information such as speech, music, audio, images and video, frequently exists in the natural world as analog information. As is well-known to those skilled in the art, recent advances in very large scale integration (VLSI) digital computer technology have enabled both discrete and analog information to be represented with digital data. Continuous information represented as digital data is often referred to as diffuse data. Diffuse digital data is thus a representation of data that is of low information density and is typically not easily recognizable to humans in its native form.
There are many advantages associated with digital data representation. For instance, digital data is more readily processed, stored, and transmitted due to its inherently high noise immunity. In addition, the inclusion of redundancy in digital data representation enables error detection and/or correction. Error detection and/or correction capabilities are dependent upon the amount and type of data redundancy, available error detection and correction processing, and extent of data corruption.
One outcome of digital data representation is the continuing need for increased capacity in data processing, storage, and transmittal. This is especially true for diffuse data where increases in fidelity and resolution create exponentially greater quantities of data. Data compression is widely used to reduce the amount of data required to process, transmit, or store a given quantity of information. In general, there are two types of data compression techniques that may be utilized either separately or jointly to encode/decode data: lossless and lossy data compression.
Lossy data compression techniques provide for an inexact representation of the original uncompressed data such that the decoded (or reconstructed) data differs from the original unencoded/uncompressed data. Lossy data compression is also known as irreversible or noisy compression. Entropy is defined as the quantity of information in a given set of data. Thus, one obvious advantage of lossy data compression is that the compression ratios can be larger than the entropy limit, all at the expense of information content. Many lossy data compression techniques seek to exploit various traits within the human senses to eliminate otherwise imperceptible data. For example, lossy data compression of visual imagery might seek to delete information content in excess of the display resolution or contrast ratio.
On the other hand, lossless data compression techniques provide an exact representation of the original uncompressed data. Simply stated, the decoded (or reconstructed) data is identical to the original unencoded/uncompressed data. Lossless data compression is also known as reversible or noiseless compression. Thus, lossless data compression has, as its current limit, a minimum representation defined by the entropy of a given data set.
There are various problems associated with the use of lossless compression techniques. One fundamental problem encountered with most lossless data compression techniques are their content sensitive behavior. This is often referred to as data dependency. Data dependency implies that the compression ratio achieved is highly contingent upon the content of the data being compressed. For example, database files often have large unused fields and high data redundancies, offering the opportunity to compress data at ratios of 5 to 1 or more. In contrast, concise software programs have little to no data redundancy and, typically, will not losslessly compress better than 2 to 1.
Another problem with lossless compression is that there are significant variations in the compression ratio obtained when using a single lossless data compression technique for data streams having different data content and data size. This process is known as natural variation.
A further problem is that negative compression may occur when certain data compression techniques act upon many types of highly compressed data. Highly compressed data appears random and many data compression techniques will substantially expand, not compress this type of data.
For a given application, there are many factors which govern the applicability of various data compression techniques. These factors include compression ratio, encoding and decoding processing requirements, encoding and decoding time delays, compatibility with existing standards, and implementation complexity and cost, along with the adaptability and robustness to variations in input data. A direct relationship exists in the current art between compression ratio and the amount and complexity of processing required. One of the limiting factors in most existing prior art lossless data compression techniques is the rate at which the encoding and decoding processes are performed. Hardware and software implementation tradeoffs are often dictated by encoder and decoder complexity along with cost.
Another problem associated with lossless compression methods is determining the optimal compression technique for a given set of input data and intended application. To combat this problem, there are many conventional content dependent techniques which may be utilized. For instance, filetype descriptors are typically appended to file names to describe the application programs that normally act upon the data contained within the file. In this manner data types, data structures, and formats within a given file may be ascertained. Fundamental problems with this content dependent technique are:
(1) the extremely large number of application programs, some of which do not possess published or documented file formats, data structures, or data type descriptors; PA1 (2) the ability for any data compression supplier or consortium to acquire, store, and access the vast amounts of data required to identify known file descriptors and associated data types, data structures, and formats; and PA1 (3) the rate at which new application programs are developed and the need to update file format data descriptions accordingly. PA1 (a) receiving as input a block of data from a stream of data, the data stream comprising one of at least one data block and a plurality of data blocks; PA1 (b) counting the size of the input data block; PA1 (c) encoding the input data block with a plurality of lossless encoders to provide a plurality of encoded data blocks; PA1 (d) counting the size of each of the encoded data blocks; PA1 (e) determining a lossless data compression ratio obtained for each of the encoders by taking the ratio of the size of the encoded data block output from the encoders to the size of the input data block; PA1 (f) comparing each of the determined compression ratios with an a priori user specified compression threshold; PA1 (g) selecting for output the input data block and appending a null data type compression descriptor to the input data block, if all of the encoder compression ratios fall below the a priori specified compression threshold; and PA1 (h) selecting for output the encoded data block having the highest compression ratio and appending a corresponding data type compression descriptor to the selected encoded data block, if at least one of the compression ratios exceed the a priori specified compression threshold.
An alternative technique that approaches the problem of selecting an appropriate lossless data compression technique is disclosed in U.S. Pat. No. 5,467,087 to Chu entitled "High Speed Lossless Data Compression System" ("Chu"). FIG. 1 illustrates an embodiment of this data compression and decompression technique. Data compression 1 comprises two phases, a data pre-compression phase 2 and a data compression phase 3. Data decompression 4 of a compressed input data stream is also comprised of two phases, a data type retrieval phase 5 and a data decompression phase 6. During the data compression process 1, the data pre-compressor 2 accepts an uncompressed data stream, identifies the data type of the input stream, and generates a data type identification signal. The data compressor 3 selects a data compression method from a preselected set of methods to compress the input data stream, with the intention of producing the best available compression ratio for that particular data type.
There are several problems associated with the Chu method. One such problem is the need to unambiguously identify various data types. While these might include such common data types as ASCII, binary, or unicode, there, in fact, exists a broad universe of data types that fall outside the three most common data types. Examples of these alternate data types include: signed and unsigned integers of various lengths, differing types and precision of floating point numbers, pointers, other forms of character text, and a multitude of user defined data types. Additionally, data types may be interspersed or partially compressed, making data type recognition difficult and/or impractical. Another problem is that given a known data type, or mix of data types within a specific set or subset of input data, it may be difficult and/or impractical to predict which data encoding technique yields the highest compression ratio.
Chu discloses an alternate embodiment wherein a data compression rate control signal is provided to adjust specific parameters of the selected encoding algorithm to adjust the compression time for compressing data. One problem with this technique is that the length of time to compress a given set of input data may be difficult or impractical to predict. Consequently, there is no guarantee that a given encoding algorithm or set of encoding algorithms will perform for all possible combinations of input data for a specific timing constraint. Another problem is that, by altering the parameters of the encoding process, it may be difficult and/or impractical to predict the resultant compression ratio.
Other conventional techniques have been implemented to address the aforementioned problems. For instance, U.S. Pat. No. 5,243,341 to Seroussi et al: describes a class of Lempel-Ziv lossless data compression algorithms that utilize a memory based dictionary of finite size to facilitate the compression and decompression of data. A second standby dictionary is included comprised of those encoded data entries that compress the greatest amount of input data. When the current dictionary fills up and is reset, the standby dictionary becomes the current dictionary, thereby maintaining a reasonable data compression ratio and freeing up memory for newly encoded data strings. Multiple dictionaries are employed within the same encoding technique to increase the lossless data compression ratio. This technique demonstrates the prior art of using multiple dictionaries within a single encoding process to aid in reducing the data dependency of a single encoding technique. One problem with this method is that it does not address the difficulties in dealing with a wide variety of data types.
U.S. Pat. No. 5,717,393 to Nakano, et al. teaches a plurality of code tables such as a high-usage code table and a low-usage code table in an entropy encoding unit. A block-sorted last character string from a block-sorting transforming unit is the move-to-front transforming unit is transformed into a move-to-front (MTF) code string. The entropy encoding unit switches the code tables at a discontinuous part of the MTF code string to perform entropy coding. This technique increases the compression rate without extending the block size. Nakano employs multiple code tables within a single entropy encoding unit to increase the lossless data compression ratio for a given block size, somewhat reducing the data dependency of the encoding algorithm. Again, the problem with this technique is that it does not address the difficulties in dealing with a wide variety of data types.
U.S. Pat. No. 5,809,176 to Yajima discloses a technique of dividing a native or uncompressed image data into a plurality of streams for subsequent encoding by a plurality of identically functioning arithmetic encoders. This method demonstrates the technique of employing multiple encoders to reduce the time of encoding for a single method of compression.
U.S. Pat. Nos. 5,583,500 and 5,471,206 to Allen, at al. disclose systems for parallel decompression of a data stream comprised of multiple code words. At least two code words are decoded simultaneously to enhance the decoding process. This technique demonstrates the prior art of utilizing multiple decoders to expedite the data decompression process.
U.S. Pat. No. 5,627,534 to Craft teaches a two-stage lossless compression process. A run length precompressed output is post processed by a Lempel-Ziv dictionary sliding window dictionary encoder that outputs a succession of fixed length data units. This yields a relatively high-speed compression technique that provides a good match between the capabilities and idiosyncrasies of the two encoding techniques. This technique demonstrates the prior art of employing sequential lossless encoders to increase the data compression ratio.
U.S. Pat. No. 5,799,110 to Israelsen, et al. discloses an adaptive threshold technique for achieving a constant bit rate on a hierarchical adaptive multistage vector quantization. A single compression technique is applied iteratively until the residual is reduced below a prespecified threshold. The threshold may be adapted to provide a constant bit rate output. If the nth stage is reached without the residual being less than the threshold, a smaller input vector is selected.
U.S. Pat. No. 5,819,215 to Dobson, et al. teaches a method of applying either lossy or lossless compression to achieve a desired subjective level of quality to the reconstructed signal. In certain embodiments this technique utilizes a combination of run-length and Huffman encoding to take advantage of other local and global statistics. The tradeoffs considered in the compression process are perceptible distortion errors versus a fixed bit rate output. | {
"pile_set_name": "USPTO Backgrounds"
} |
The potential of lactic acid as a commodity chemical, for example for use in the production of various industrial polymers, is known. This has been described, for example, in U.S. Pat. Nos.: 5,142,023; 5,247,058; 5,258,488; 5,357,035; 5,338,822; 5,446,123; 5,539,081; 5,525,706; 5,475,080; 5,359,026; 5,484,881; 5,585,191; 5,536,807; 5,247,059; 5,274,073; 5,510,526; and 5,594,095. (The complete disclosures of these seventeen patents, which are owned by the assignee of the present application, Cargill, Inc. of Minneapolis, Minn., are incorporated herein by reference.) There has been general interest in developing improved techniques for generation and isolation of lactic acid. Also, because of their potential commercial value, there is great interest in isolation of the other valuable related lactate products such as lactide, lactate esters and amides, and oligomers; see e.g. the same 17 patents.
In general, large amounts of lactic acid can be readily generated by the conduct of large-scale, industrial, bacterially-conducted fermentation processes, particularly using carbohydrates, such as dextrose, as the feed stock, along with suitable mineral and amino acid based nutrients. Typically, such productions occur at broth temperatures of at least 45.degree. C., usually around 48.degree. C.
Issues of concern with respect to lactic acid generation include, inter alia, appropriate control of pH within the fermentation system to ensure proper environment for bacterial action; separation and isolation of either or both of lactic acid and lactate salts from the fermentation process; and downstream isolation and production involving the isolated lactic acid or lactic acid derived product. | {
"pile_set_name": "USPTO Backgrounds"
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The present invention relates to a paper wrapper construction for use in conjunction with a smoking article, such as a cigarette. Specifically the paper wrapper of this invention can be used to effectively control the burn rate of the smoking article. The paper wrapper of the present invention comprises cellulosic material which is applied to regions of a base paper web.
It is beneficial to make cigarettes in commercial quantities which will have a reduced burn rate if not drawn on by the smoker but which look, feel, taste and burn like conventional cigarettes when being drawn on by the smoker at normal intervals. It is recognized by those skilled in the art that the wrapper configuration and construction strongly influences these characteristics.
Cigarette wrappers, i.e., papers, have known burn characteristics, including burn rates and static burn capabilities. There have been various attempts to modify the burn characteristics of such wrappers. These attempts have employed a variety of wrapper configurations and constructions.
For example, it is known that the burn characteristics can be modified by adding fillers, coatings, or additives to the papers. Weinert U.S. Pat. No. 4,489,650 refers to a self-extinguishing cigarette in which the interior surface of the wrapper is coated with clay. In Cohn U.S. Pat. No. 4,044,778, the cigarette wrapper referred to includes rings or areas coated with deposits from an alkali silicate solution which renders the wrapper non-burning in the coated areas.
In Adams et al. U.S. Pat. No. 4,889,145, the cigarette wrapper referred to includes an area containing a coating of a porosity reducing composition. The coating is comprised of a non-polymer with a polymer binder. Examples of the non-polymer were given as a fatty alcohol and a fatty acid salt.
Durocher U.S. Pat. No. 4,615,345 refers to another attempt to modify the burn characteristics of wrappers. In Durocher the wrapper is made of a cellulose fiber base which normally does not sustain burning when the wrapper is incorporated into a cigarette. This type of wrapper is treated in selected zones with an alkali metal burn promoter such as the potassium salt of citric acid. It is referred to therein that a cigarette made with a wrapper so treated will smolder without being drawn on by the smoker when in the treated zone but when the treated zone is consumed will extinguish itself unless the cigarette is drawn on by the smoker.
Baker et al. U.S. Pat. No. 4,077,414 also refers to a wrapper with modified burn characteristics. In Baker, a wrapper with inherently high porosity is modified by treating the paper with what was referred to as a "gel-forming" substance so as to produce bands of low porosity regions. The "gel-forming" substances disclosed in Baker were all soluble in water and thus were solutions, as opposed to slurries, when applied to the cigarette paper wrapper.
In addition to modifying wrapper burn characteristics by adding fillers, coatings or burn additives directly to the base paper web, burn characteristics have been shown to be able to be modified by applying to the base paper web a strip or patch of a paper having different characteristics than the base web to be modified. For example, it is shown in co-pending, commonly-assigned U.S. patent application Ser. No. 07/605,402, filed Oct. 30, 1990, that cigarette paper can be modified by applying strips of a different paper at periodically spaced positions across the width of the paper web, so that cigarettes produced from the paper web have periodically spaced circumferential bands on the inside of the paper for modifying the burning characteristics of the paper and the cigarette. One treated paper material suitable for forming the periodically spaced strips is described in Hampl U.S. Pat. No. 4,739,775. However, the wrappers discussed in Hampl were formed by the adhesion of the treated paper material to the base paper web by a process which would be difficult and costly to use for mass production.
As discussed above, various types of cigarette wrapper configurations have been proposed for modifying the burn characteristics of cigarettes. However, these wrappers have various problems and disadvantages. Although the wrappers of Weinert and Cohn produce cigarettes with modified burn characteristics, they do not look, feel, taste and burn like conventional cigarettes when being drawn on by the smoker. Although the wrappers of Durocher solve some of the problems exhibited by the Weinert and Cohn wrappers, Durocher did not disclose a process for making such cigarette wrappers in commercial quantities. In addition, although co-pending application Ser. No. 07/605,402 discloses commercially feasible methods that can produce wrappers with both modified burn characteristics and that look, feel, taste and burn like a conventional cigarette when being drawn on by the smoker, such methods are not the only solutions to the problems discussed. Additionally, the wrappers and coatings referred to in Baker et al. and Adams et al. are not the only types that can potentially modify the burn rate of a cigarette.
Johnson U.S. Pat. No. 4,861,427 refers to a fibrous web product with bacterial cellulose as a surface treatment. In Johnson the bacterial cellulose treatment referred to is applied to the entire web. The resulting coating web is used as printing materials which have gloss, smoothness, ink receptivity and surface strength.
Johnson does not refer to the application of the cellulose to papers in selected portions of the web, i.e., in bands or other patterns, nor does Johnson refer to burn control properties that such an application of bacterial cellulose will impart to the resulting paper. Johnson does not disclose the use of the coated web for cigarette paper.
It would be desirable to provide a paper wrapper for a smoking article that effectively controls the burn rate of the smoking article.
It would also be desirable to provide a paper wrapper for a smoking article that looks, feels, tastes and burns like a conventional cigarette when being drawn on by the smoker.
It would further be desirable to provide a paper wrapper in which burn rate control can be achieved economically with mass-production techniques. | {
"pile_set_name": "USPTO Backgrounds"
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The subject invention is directed toward the fastener art and, more particularly to an assembly for connecting associated components to relatively thin panels.
The invention is especially suited for use in the vehicle art for connecting various structures to vehicle body panels and will be described with respect thereto; however, as will become apparent, the invention is capable of broader application and could be used in many different environments for a variety of purposes.
In the manufacture of motor vehicles, it is frequently necessary to attach various structural and accessory components to sheet metal body panels. For example, roof rails have commonly been attached to the sheet metal roof panel through the use of expansible metal fasteners. Typically, the fasteners have comprised a tubular body having a flange at one end and an internally threaded portion at the other end. The fasteners are inserted through openings in the roof panel with the tubular body extending interiorly of the panel and the flange resting against the exterior surface of the panel. The barrel is arranged to radially expand and lock the fastener in the panel opening when a screw is threaded into the barrel.
The arrangement described is generally satisfactory but does suffer from certain disadvantages. The primary disadvantage is that the screw must be installed twice. First when the tubular body is expanded and again after the vehicle has been painted and the roof rail is being installed. If excessive torque is applied to the screw, the fastener can sometimes rotate resulting in an installation that can rattle and leak. | {
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1. Field of the Invention
The present invention relates to a method of reproducing a recording medium and an apparatus for reproducing the same. More particularly, the present invention relates to a method of reproducing a recording medium by compressing moving picture information, and an apparatus therefor.
2. Background of the Invention
There has been known one of the CD-ROM (CD-Read Only Memory) standards, which is called a video-CD. The video-CD in which audio information as well as moving picture information has been recorded has been put to practical use as a recording medium for a so-called "Karaoke"
In the video-CD, a moving picture signal as well as an audio signal has been compressed and encoded in conformity with the MPEG (Moving Picture Coding Expert Group) standards before being recorded.
In other words, the audio signal and moving picture signal are recorded in the following manner. The audio signal is converted into a digital signal, and then compressed by the compression coding system utilizing an audition psychology characteristic before being recorded. The moving picture signal is converted into a digital signal, and one screen is blocked in a plurality of blocks. Each of the blocks is subjected to discrete cosine transformation (DCT) so that the coding quantity is decreased in accordance with the degree of a change of an image. Codes of short lengths are allocated to the codes which have been subjected to the DCT in accordance with a VLC (Variable Length Code), as they are higher in the frequency of occurrence, so that the coding quantity are reduced as a whole.
In the case of moving picture data, a difference between an actual screen and a screen a change of which is predicted from a past screen and future screen is extracted. Then, the difference thus extracted and the predicted quantity of change are recorded, and the data quantity is also compressed. However, since a demodulated picture cannot be obtained from only data for the difference and the predicted quantity of change, picture data for one screen (1 frame) which is a reference to the data for the difference and the predicted quantity of change is compressed and encoded as it is, without referring to other pictures. In this manner, the reference picture thus compressed and encoded without referring to other pictures is called an "I-picture" (Intra Picture). Other pictures which contain change information for the I-picture is called a "P-picture" (Predicted Picture) or a "B-picture" (Bi-directional Prediction Picture).
The audio signal and moving picture signal are recorded, as shown in FIG. 1, on a disc by a sector unit established by the CD-ROM standards. In other words, in FIG. 1, Symbol V designates a sector (hereinafter referred to a "video sector") of moving picture data which has been compressed and encoded, and A designates a sector (hereinafter referred to an "audio sector") of audio data which has been compressed and encoded. Since the audio data is less than the moving picture data in the quantity of data, it is recorded in the ratio of one audio sector to a plurality of video sectors, as shown in FIG. 1.
As will be described in more detail later, information on a distinction between the audio sector and the video sector, information on an absolute time on a disc, and information on a time when a moving picture or sound is outputted at the time of reproducing (information on a correspondence in a reproducing timing between the moving picture and sound) are recorded on the respective sectors. The reproducing apparatus reproduces each music and a moving picture associated with that music on the basis of those information.
As is apparent from the above description of the compression encoding system for moving picture data, an accurate demodulated picture cannot be obtained without the I-picture. For this reason, when reproduction is started from the halfway position of a certain track (one track corresponds to one music; hereinafter, a sequence of events such as one music will be called one (1) sequence), it is difficult to obtain a accurate reproduced image unless the position of the I-picture is known.
In the format of the video-CD, in order to maintain a given image quality, the I-pictures are arranged in such a manner that one I-picture is necessarily recorded within 2 seconds. However, in the format of the original video-CD (hereinafter referred to as an "old video-CD format"), no information on the position of the I-picture is recorded on a disc. For this reason, the old video-CD format did not facilitate the start of reproduction from the halfway position of a certain track.
Thereafter, in the format of a revised video-CD format (hereinafter, referred to as a "new video-CD format"), a halfway position on a track where an image can be reproduced (hereinafter referred to as an "entry point"), after being converted into time information, is recorded on an area (a first track 1 as will be described later) where information on the number of music on the disc and recording data on the disc is recorded. The entry point is directed to information on the position of the I-picture and enables a picture to be reproduced even at the time of partially reproducing or forward feed reproducing by reproducing while referring to that point.
In the video-CD, data which has been subjected to a compression processing is recorded as the moving picture signal.
That data contains I-picture data which enables one screen to be reproduced by decoding the compression-processed data independently because the data has been subjected to compressing and encoding within one screen as described above, P-picture data which cannot be decoded without use of the I-picture, and B-picture data which cannot be decoded without use of the I-picture data and the P-picture data.
In the normal reproduction, those I-, P- and B-pictures are decoded, respectively, to output the reproduction of the moving picture. In the high-speed reproduction such as FF (fast forward) or REW (rewind), the I-picture data may be extracted discretely from the disc and then displayed.
In the high-speed reproduction, as the practical operation, the I-picture data is searched through the reproducing operation, and then decoded so that the decoded data is continuously outputted to be displayed as it looks like a still picture. Thereafter, a track jump is executed so that an I-picture is searched by executing the reproducing operation again from a jump completion point. Then, after the decoding processing is completed, the present screen is switched to a previous screen so that a picture of the I-picture decoded at this time is outputted to be displayed, and a track jump is executed. The above operation is repeated.
However, in the case where no I-picture could be found at the time of the reproducing operation, the picture of the previous I-picture is caused to be displayed for a long period of time.
For example, because the I-picture cannot be found in the duration where an optical head is scanning between two music on the disc, a picture which has previously been decoded and outputted to be displayed is continuously being displayed. Therefore, the operation is not changed to the high-speed reproducing operation.
Also, if the I-picture is decoded and display is switched immediately when the I-picture has been found, the duration from the start of displaying a certain picture to the start of displaying a next picture, that is, the length of a period of time during which each picture is displayed is dispersed. The shortened or lengthened period of time for displaying each picture makes its visibility very poor as a high-speed reproduced picture.
The above difficulties result in such problems that the visibility of a search screen as well as the usability are lowered.
Moreover, a Karaoke system has been realized which uses a video-CD conforming to the old video-CD format as a recording medium. However, in Japan, in recent years, music programs are reduced from TV programs whereby the entire music is difficult to memorize. Also, the Karaoke houses in which Karaoke systems are installed are increased. The account of loyalty to copyrights is shifted from a music unit system to a time charge system. Thus, the environments surrounding a Karaoke market are changed as a result of which the market has made the following demands for the Karaoke systems.
That is,
1) A user wishes to sing only the characteristic portions of music which is a so-called "impressive" ("Sabi" in Japanese). PA1 2) The user wishes to sing only the first or second part of a poem or to finish with singing of the second part. PA1 3) The user wishes to forwardly feed parts of music irrelevant to singing such as an interlude or a weak phrase for omission.
However, in the reproducing apparatus having the video-CD as a recording medium such as the conventional Karaoke system, there is no means for knowing the position of a specified partial sequence. For this reason, the user is required to search the start and end points of the partial sequence to manipulate the reproducing apparatus so as to realize the specified partial reproduction or omission described in the above items 1) to 3). This is troublesome. In particular, in the case of limiting the position of the partial sequence depending on music, for example, in the case of reproducing only the portion of "Sabi" (impressive), the operator must manipulate the reproducing apparatus at not only the start position of the partial sequence but also the end position of the partial sequence. Thus, the manipulation is troublesome.
As described above, in the old video-CD format, information on the position of the I-picture is not recorded on a disc. For this reason, when starting reproduction from the middle of certain music as in the above items 1) to 3), a moving picture associated with such a situation is difficult to reproduce.
In the new video-CD format, since the position of the I-picture is known as an entry point, the moving picture can be reproduced even from the middle of music. However, in the case of starting reproduction from a specified portion of music as in the above items 1) to 3), it can be specified from which entry point reproduction should be preferably started. | {
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1. Field of the Invention
The present invention is directed to the manufacture of electronic devices, and in particular electronic devices formed using one or more thin flexible sheets of an inorganic material.
2. Description of Related Art
Display devices utilizing plasma, liquid crystal, or organic light emitting diode display elements, to name a few, are fast overcoming cathode ray tube (CRT) displays in commercial products, finding use in a myriad of applications, from cell phones to televisions. However, the introduction of very thin, light weight, or flexible displays is only in its infancy. This is due in no small part to the tremendous structural demands placed on such display devices: they must be capable of withstanding repeated flexing or bending or other stress without harm to the device or the substrate on which it is disposed; due to the intended use of thin, light, or flexible displays in portable devices, they are expected to withstand rough handling, again without undue harm to the device or substrate, and; they must be capable of withstanding impact or a bending radius that can be less than 2 cm, and less than 1 cm in some cases.
One material contemplated for use in thin, light weight, or flexible displays or electronic devices is glass. Glass is generally chemically resistant, transparent, can form a hermetic barrier or seal, can tolerate typical electronic fabrication temperatures, and may be formed into very thin sheets. Sheets in excess of 10 m2 having thicknesses less than 1 mm, and even less than 0.7 mm have been produced and routinely used, and glass sheets are soon expected to reach dimension of at least about 100 m2. In a typical display manufacturing process, multiple displays are formed using one or more large glass sheets or substrates. The displays are then separated into individual display units, usually by scoring and breaking or other cutting methods. Thus, very large glass sheets are efficiently utilized by producing as many display or electronic units as possible.
Cutting glass, and in this case glass sheets, generally forms flaws (e.g. cracks) in the edges of the glass sheets. These flaws can serve as crack initiation sites, and thereby reduce the strength of the sheets, particularly if the glass is flexed such that the flaw experiences tensile stress. Generally, typical display devices do not experience significant flexing, thus the existence of these flaws is not of significant concern: Typical cutting methods produce edges of sufficient strength to survive both the standard device processing conditions and current application end use.
Shown in FIG. 1 is a Weibull plot showing the failure probability for 75 micron thick glass sheets in four-point bending according to standardized four-point bending tests (e.g. ASTM). The samples in this case were 5 mm wide×30 mm long×75 microns thick. The samples were tested in a four-point bend arrangement standing on edge so the tensile stress was applied across the entire 75 um face thickness. The glass sheet represented by curves 10 and 12 were laser cut, while the glass sheet represented by curve 14 was mechanically scribed and separated by bending to fracture the sheet. As depicted, none of the samples represented by the curves showed a high probability of withstanding a stress in excess of about 300 MPa. The samples for mechanical scoring, the most widespread method of separating glass, did not show a high probability of withstanding a stress in excess of 100 MPa. Although standard cutting methods for glass substrates greater than 0.4 mm thick address the needs of current device manufacturing processes or application end use, higher edge strength is required for substrates less than 0.4 mm thick as may be used in emerging processes and applications such as flexible displays.
Flexible displays or flexible electronic devices, by the very nature of their flexibility, may produce significant stress in the display or electronic substrate(s), either during the manufacturing process or in use. Thus, flaws that might be present in the glass may experience stresses sufficiently great that the glass will crack, causing the glass to fail. Since typical display manufacturing involves cutting the glass to form individual displays, and cutting is known to create multiple flaws in the glass along the cut edge, this bodes poorly for the fate of glass substrate-based flexible display devices.
Attempts to mitigate flaws at the edges of glass sheets have included laser cutting, grinding, polishing and so forth, all in the attempt to remove or minimize the flaws that are created when the glass sheet is cut to size. However, many of these approaches are unsatisfactory for flexible electronic applications, either because the technique is incapable of removing flaws down to the size needed for the expected stresses, or the technique is difficult to apply to such thin glass sheets (less than about 0.4 mm thick) in a manufacturable process or scale. Acid etching of the glass edges may be used, but acid etching may also degrade the display or electronic device disposed on the substrate. | {
"pile_set_name": "USPTO Backgrounds"
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Co-owned U.S. Pat. No. 7,295,731 B2 describes a method for using femtosecond laser radiation for the creation of optical waveguiding devices inside standard optical fibers. The femtosecond laser is focused inside the optical fiber and the intense light generated in the focal region produces non-linear absorption in the glass fiber and creates permanent refractive index changes. The different refractive index regions can be used to produce waveguide vias for light to travel, thus functionalizing the fiber for applications beyond their original intent. For example, these waveguides can be made to interact with the fiber core and allow light to be coupled from the core to the fiber cladding. This technique can be used to form applications such as local light tapping for power monitoring, cladding waveguides for sensing, periodic structures such as Bragg grating for light filters, and others.
Photonic crystal fibers have been established for years and they confine and guide light, not by having a core with a positive index difference to its surroundings, but instead by creating a light band gap, with subsequent confinement, around the center of the fiber by means of strategically positioned hollow (usually air filled) holes. The band gap structure guides the light in the center of the fiber, typically a solid core with a material that is the same as the material composing the rest of the solid portions of the fiber (typically fused silica/quartz glass). However, in certain configurations, the core itself may also be formed by a hollow hole and still guide the light in its center. Other types of fibers such as suspended core fibers also utilize hollow structure to form a cladding surrounding a solid core. In this case, the hollow areas are typically larger than the core itself and are connected by thin solid bridges that hold the structure together.
The hollow holes in all these types of fibers, with their very low refractive index when compared to glass fiber, are fundamental to the creation of a photonic band gap and to the working principle of this class of light waveguides. However these structures also present a challenge for the fabrication of waveguides with femtosecond lasers. Since there is no material to be modified inside those holes, the methods that form the current state of the art are not adequate and the introduction of other non-obvious elements to the fabrication procedures are required in order to have a means to achieve the same potential for the local creation of devices as is currently possible in standard optical fibers with femtosecond laser writing. | {
"pile_set_name": "USPTO Backgrounds"
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This invention relates generally to journal bearings and more specifically to a retainer system for journal bearings. More particularly, this invention relates to a retainer system for use with journal bearing sleeves made of a hard brittle material, for example, silicon carbide.
Conventional journal bearing sleeves are installed in holders by methods such as pressing, shrink fitting, adhesives, and interference rings. Bearing sleeves installed using these methods are frequently not in proper alignment after installation and need to be machined in order to place them in proper alignment.
A bearing sleeve made of silicon carbide cannot be pressed into stainless steel because it galls the stainless steel. It cannot be machined and is subject to breaking under bending or tension stresses. It cannot be drilled or tapped which would be necessary for the use of screws to fasten it in a holder. Thus, it must be installed in correct alignment to avoid problems.
The foregoing illustrates limitations known to exist in present devices and methods. It is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter. | {
"pile_set_name": "USPTO Backgrounds"
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The semiconductor industry has experienced rapid growth due to improvements in the integration density of a variety of electronic components (e.g., transistors, diodes, resistors, capacitors, etc.). For the most part, this improvement in integration density has come from shrinking the semiconductor process node (e.g., shrinking the process node towards the sub-20 nm node). As device dimensions shrink, voltage nodes also shrink, with modern core device voltages trending toward less than 1 Volt, and input/output (I/O) device voltages under 2 Volts.
Many types of analog, digital and mixed-signal circuits rely on tuning networks to achieve fine granularity in performance metrics, such as gain, bandwidth, center frequency, oscillation frequency, and the like. The tuning networks are often designed with a view to increase resolution while maintaining or shrinking area and also guarding against process, voltage, and temperature (PVT) variation. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates generally to electron guns for cathode ray tubes (CRTs) and more specifically to electron guns of the type used with monochrome tubes suitable for projection-type television receivers.
2. Discussion of the Related Art
In order to produce a high resolution image on a CRT raster, the electron beam which is swept over the phosphor screen must be well focused and of small size. Spherical aberrations inherent in the electron-optical lenses of the electron gun which forms and emits the electron beam can create distorted beam "spots" at the screen which become larger-than-optimal size. In order to reduce spherical aberrations in the gun and, therefore, achieve a smaller or better focused beam spot, lenses with larger apparent apertures are desirable within the electron gun structure. However, lens sizes are limited by the size of the CRT neck which the gun must fit within. Past teachings which expound upon and address these problems include U.S. Pat. No. 4,904,898 to Penird et al.; U.S. Pat. No. 4,271,374, to Kimura; U.S. Pat. No. 4,649,318 to Kukuchi et al.; and U.S. Pat. No. 4,728,846 to Yasuda. Each of these references illustrate what is herein called an "immersion" lens, where the lower potential grid of the accelerating portion of the main lens is fitted partially within the higher potential grid in order to achieve a larger apparent lens aperture with reduced spherical aberration. Kimura, Penird et al., and Kukuchi et al. describe einzel-type guns, while Yasuda shows a bipotential type gun. All of the cited references show an immersion lens for the accelerating portion of the main lens, which is the G3-G4 gap in the bipotential gun of Yasuda and the G4-G5 gap of the einzel guns of the others.
A further consideration for the operation of such guns, as recognized in the Penird et al. patent, is that the electron guns in projection-type CRTs are operated at higher voltages than direct-view CRTs in order to provide adequate brightness. Therefore, high voltage stability of the gun and the prevention of arcing between the grids, becomes of increasing concern while still maintaining an adequate spot size. The cited references are somewhat elaborate structurally, thus requiring intensive effort in forming the grids and/or assembling them into the gun to prevent artifacts such as burrs and microcracks on the smooth surfaces of the grids which would lead to high voltage instability. Further effort must be taken with the cited designs to prevent axial misalignments of the grids in relation to one another which may skew the lensing action of the grids and result in beam asymmetries or large spot sizes.
Certain structural improvements to the gun designs of the prior art are, therefore, desired in order to decrease spot size for high resolution while gaining high voltage stability and ease of manufacture of the gun. | {
"pile_set_name": "USPTO Backgrounds"
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A Mop is a tool commonly used for house cleaning, and a mop holder is a device for fixing the mop cloth. A conventional mop holder usually comprises a screw, when changing a mop cloth, said screw is released and new mop cloth is placed on the holder, afterward, the screw is tighten to hold the mop cloth again. This technique is relatively complex and since the mop contacts with water constantly, screw may oxidize easily, increasing difficulty to release the screw. | {
"pile_set_name": "USPTO Backgrounds"
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The ability of natural products and other compounds to act as proteasome inhibitors has attracted significant interest because of the wide range of cellular substrates and processes controlled or affected by the ubiquitin-proteasome pathway. For example, the oscillation of cyclins (cell cycle proteins required for the orderly progression through the cell cycle) has been found to be due to the regulated degradation mediated by the ubiquitin-proteasome pathway, and inhibition of this pathway is believed to result in the blockage of cell cycle progression. Additionally, the transcription factor NF-kB is another regulatory protein involved in a variety of cellular processes, including immune and inflammatory responses, apoptosis, and cellular proliferation, whose mode of action is controlled by the ubiguitin-proteasome pathway. Furthermore, it has also been shown that the ubiquitin-proteasome pathway is involved in retrovirus assembly and thus may be a useful target for the development of anti-HIV drugs. For a general discussion of the ubiquitin-proteasome pathway and proteasome inhibitors see, Myung et al. “The Ubiquitin-Proteasome Pathway and Proteasome Inhibitors” Medicinal Research Reviews 2001, 21, 245-273. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of Use
The present invention relates generally to an underwater communications system, and its methods of use, and more particularly to an underwater communications system that uses electromagnetic propagation and magnetic induction transmission, and optimizes the distance which can be achieved by digital transmission of information.
2. Description of the Related Art
Various underwater communication systems are known. One of the most common is based on acoustic techniques. A problem with such systems is that they are degraded by noise and interference from a number of sources. They are also subject to multi-path effects and in some environments are virtually unusable. Other underwater communication systems use radio links, e.g. extreme low frequency electromagnetic signals, usually for long-range communications between a surface station and a submerged vessel. These systems typically operate in the far field using physically large electric field coupled antennas and support data rates up to a few bits per second.
WO01/95529 describes an underwater communications system that uses electromagnetic signal transmission. This system has a transmitter and a receiver, each having a metallic, magnetic coupled aerial surrounded by a waterproof electrically insulating material. Use of electrically insulated magnetic coupled antennas in the system of WO01/95529 provides various advantages. This is because magnetically coupled antennas launch a predominantly magnetic field. A similar arrangement is described in GB2163029. Whilst the communications systems of WO01/95529 and GB2163029 have some technical advantages over more conventional acoustic or radio link systems, the functionality described is limited, and for many practical applications the available bandwidth is highly restrictive, as is distance over which data can be transmitted.
Magnetic antennas formed by a wire loop, coil or similar arrangements create both magnetic and electromagnetic fields. The magnetic or magneto-inductive field is generally considered to comprise two components of different magnitude that, along with other factors, attenuate with distance (r), at rates proportional to 1/r2 and 1/r3 respectively. Together they are often termed the near field components. The electromagnetic field has a still different magnitude and, along with other factors, attenuates with distance at a rate proportional to 1/r. It is often termed the far field or propagating component.
Signals based on electrical and magnetic fields are rapidly attenuated in water due to its partially electrically conductive nature. Seawater is more conductive than fresh water and produces higher attenuation. Propagating radio or electromagnetic waves are a result of an interaction between the electric and magnetic fields. The high conductivity of seawater attenuates the electric field. Water has a magnetic permeability close to that of free space so that a purely magnetic field is relatively unaffected by this medium. However, for propagating electromagnetic waves the energy is continually cycling between magnetic and electric field and this results in attenuation of propagating waves due to conduction losses.
The attenuation losses, the bandwidth restrictions and the limited distances over which data can be transmitted all pose significant practical problems for underwater communications.
Existing methods of acoustic communication are inherently restricted in the distance they can achieve at effective data rates. This is particularly true where the signal reaches a receiver by multiple paths (reflections occurring from an irregular sea floor, the sea surface, the coastline, nearby objects and the like, we well as when the sound wave path exhibits discontinuities in its properties (wave wash, bubbles in the water, changes in water density due to salinity variations). Little is known which can lessen these difficulties. The existing art of electromagnetic communication under water fails to recognize measures that can be taken to maximize the distance and/or useful information rate which can be achieved by adapting the devices sourcing and using the information so that more effective signal frequencies can be adopted. | {
"pile_set_name": "USPTO Backgrounds"
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The present application relates generally to an improved data processing system and method. More specifically, the present application is directed to a system and method for temporary pipeline marking for processor error workarounds.
In modern processor design, especially in an out-of-order processor design, design flaws in a pipeline can result in control state information living beyond the instruction for which it is intended, resulting in incorrect processing of the next instruction in that pipeline. Hung state information (as this form of design error refers to) is one of the most difficult problems to find and solve during a design phase, and are often not found until later when the design is implemented in hardware.
As another example, one or more state values used by a state machine that manages a pipeline in a processor can have a hung or stuck state value if the pipeline is at least partially cleared by a pipeline flush or an instruction rescind. In the processor, conditions can occur which require instructions currently executing in execution unit hardware of the processor to be flushed. For example, branches, load operations that miss the cache, exceptions, and the like can result in a pipeline flush. When instructions are flushed, state machines and control sequencers may need to be reset for the next operation to be executed successfully.
Failure to properly flush state from the control hardware of an execution unit is a source of design errors in processor designs, particularly for cases where complex instructions iteratively run for many cycles in the execution hardware (divide operations, for example). If a design error that results in an incomplete state reset for a particular instruction or instruction type is caught early in the design process, the design can be fixed without substantial penalty. However, if the design error is not detected until late in the design process, developing a workaround can be difficult. | {
"pile_set_name": "USPTO Backgrounds"
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Many types of input devices are presently available for performing operations in a computing system, such as buttons or keys, mice, trackballs, joysticks, touch sensor panels, touch screens, and the like. Touch sensitive devices, such as touch screens, in particular, are becoming increasingly popular because of their ease and versatility of operation. A touch sensitive device can include a touch sensor panel, which can be a clear panel with a touch-sensitive surface, and a display device, such as a liquid crystal display (LCD), that can be positioned partially or fully behind the panel so that the touch-sensitive surface can cover at least a portion of the viewable area of the display device. The touch sensitive device can allow a user to perform various functions by touching the touch sensor panel using a finger, stylus, or other object at a location often dictated by a user interface (UI) being displayed by the display device. In general, the touch sensitive device can recognize a touch event and the position of the touch event on the touch sensor panel, and the computing system can then interpret the touch event in accordance with the display appearing at the time of the touch event, and thereafter can perform one or more actions based on the touch event.
Some touch sensitive devices that incorporate touch sensor panels can include FPCs for routing signals indicative of a touch event to and from the touch sensor panel. Other devices, such as LCDs, organic light-emitting diode (OLED) displays, printed circuit boards, and the like, can also include FPCs for routing signals. While relatively small, the FPCs can still add to the size of the device and block critical areas that could otherwise be used for other device components, such as receivers, cameras, and the like. Thus, compact FPCs are desired. | {
"pile_set_name": "USPTO Backgrounds"
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The invention relates to a device or devices for sensing specified conditions in and out of fluid and has particular application as a swimming pool alert alarm for sensing persons or animals in or around the swimming pool as well as sensing a man overboard.
There are a number of sensing devices for this purpose available at least in the prior art. Some of these devices are as follows:
U.S. Pat. No. 3,054,096 awarded to S. Peritz teaches an emergency alarm particularly adaptable for use in a swimming pool. The device is adapted to float on the surface of the water and includes a pendulum which activates an audio alarm when sufficient water motion moves the pendulum to complete the alarm energizing circuit connected thereto. This device has certain drawbacks, namely, it is wind activated as well as by objects falling into the pool water and is an obstruction to authorized users of the swimming pool. If the device were adjusted whereby all but strong wind gusts were not detected then small children or animals would most probably not be detected either. The electrical circuit could be exposed to water rendering the device inoperable.
U.S. Pat. No. 3,475,746, awarded to inventors L. H. Nelson et al., teaches a self contained device that floats freely on the surface of a pool or the like. When the liquid in the pool is disturbed, a flexible diaphragm responds to pneumatic pressure producing a chamber containing air by wave motion to actuate a signaling device which continues to operate until turned off. This teaching encounters the same problems as the Peritz Patent discussed above.
U.S. Pat. No. 3,486,166, awarded to inventors N. L. Campana et al., teaches an alarm system for swimming pools which operates by submerging the sensing means (hydrophone) into the pool water. This system could only be installed at great economic expense to the pool owner and could not be removed from the pool for use elsewhere, etc.
U.S. Pat. No. 3,808,887, awarded to Albert T. Buttress, teaches the use of fibre optics to monitor liquid levels in a light transparent tank. This reference does not teach the use of fibre optics submerged in a liquid for measuring surface impact of that liquid.
U.S. Pat. No. 4,187,502, awarded to Frank O. Beverly et al., teaches a swimming pool alarm with a pressure transducer immersed into the swimming pool water. This system is expensive to produce, places the electronics in a position susceptible to water damage and could be triggered by external noise.
U.S. Pat. No. 4,408,193, awarded to Theodore I. Millen, teaches a swimming pool alarm system which monitors wave motion. This system has the obvious wind generated wave problems discussed above.
There has not been a completely successful swimming pool alarm system until the emergence of this invention. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention relates to molded plastic containers for housing cosmetics and personal care items, such as cologne, after shave, perfume, face powder, face cream, and the like.
2. Description of the Related Art
Heretofore numerous types of organizers and storage units, both molded and metal, have been proposed and produced in which cosmetic products in their containers are housed. In most cases, the storage capability of such units is limited both internally and externally. Internally, past units have organized cosmetics through sectional dividers. Such an approach may seem advantageous in theory but, in practice, the users eventually find themselves abandoning sectional assignments in favor of expedient storage, the end result being a disorganized collection of arbitrary cosmetics. Externally, past units have been designed to horizontally stand alone. This design has prohibited users from making the best use of vertical space, which has created an overall problem of storage space for the units themselves. | {
"pile_set_name": "USPTO Backgrounds"
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Pyrrolo[2,1-c][1,4]benzodiazepine antitumour antibiotics are commonly known as anthramycin class of compounds. In the last few years, a growing interest has been shown in the development of new pyrrolo[2,1-c][1,4]benzodiazepines (PBDs). These antibiotics react covalently with DNA to form an N2-guanine adduct that lies within the minor groove of duplex DNA via an acid-labile aminal bond to the electrophilic imine at the N10-C11 position (Kunimoto, S.; Masuda, T.; Kanbayashi, N.; Hamada, M.; Naganawa, H.; Miyamoto, M.; Takeuchi, T.; and Unezawa, H. J. Antibiot., 1980, 33, 665.; Kohn, K. W. and Speous, C. L. J. Mol. Biol., 1970, 51, 551.; Hurley, L. H., Gairpla, C. and Zmijewski, M. Biochem. Biophys. Acta, 1977, 475, 521.; Kaplan, D. J. and Hurley, L. H. Biochmestry, 1981, 20, 7572). The molecules have a right-handed twist, which allows them to follow the curvature of the minor groove of B-form double-stranded DNA spanning three base pairs. A recent development has been the linking of two PBD units through their C-8 positions to give bisfunctional alkylating agents capable of cross-linking DNA (Thurston, D. E.; Bose, D. S.; Thomson, A. S.; Howard, P. W.; Leoni, A.; Croker, S. J.; Jenkins, T. C.; Neidle, S. and Hurley, L. H. J. Org. Chem., 1996, 61, 8141).
Recently, PBD dimers have been developed that comprises two C2-exo-methylene substituted DC-81 subunits tethered through their C-8 position via an inert propanedioxy linker (Gregson, S. J.; Howard, P. W.; Hartely, J. A.; Brooks, N. A.; Adams, L. J.; Jenkins, T. C.; Kelland, L. R. and Thurston, D. E. J. Med. Chem. 2001, 44, 737). Recently, a noncross-linking mixed imine-amide PBD dimers have been synthesized that have significant DNA binding ability and potent antitumour activity. (Kamal, A.; Ramesh, G.; Laxman, N.; Ramulu, P.; Srinivas, O.; Neelima, K.; Kondapi, A. K.; Srimu, V. B.; Nagarajaram, H. M. J. Med. Chem. 2002, 45, 4679).
Naturally occurring pyrrolo[2,1-c][1,4]benzodiazepines belong to a group of antitumour antibiotics derived from Streptomyces species. Recently, there is much impetus for the PBD systems as they can recognize and bind to specific sequence of DNA. Examples of naturally occurring PBD's include anthramycin, DC-81, tomaymycin, sibiromycin and neothramycin.
However, the clinical efficacy for these antibiotics is hindered by several limitations, such as poor water solubility, carbiotoxicity, development of drug resistance and metabolic inactivation. | {
"pile_set_name": "USPTO Backgrounds"
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Recently, as lighting devices comprising light emitting diodes (LEDs) are used as replacement to traditional lighting devices such as conventional light bulbs, they also start being targeted at application of fluorescent tubes. U.S. Pat. No. 7,114,830 B2 discloses such a lighting device, which comprises an elongated, hollow, rigid tube into which a plurality of LEDs are inserted. The elongated, hollow tube provides a light mixing chamber with a light exit surface for light provided by the LEDs. The tube is rigid and typically made of a sturdy plastic or glass, which limits the flexibility of the manufacturing and installation of the LEDs and other functionalities of the lighting device into the tube. The lighting device is intended for use as direct replacement for a conventional fluorescent light tube in a conventional fluorescent lighting fixture. | {
"pile_set_name": "USPTO Backgrounds"
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The invention relates generally to Langmuir troughs which are used to deposit monomolecular layers of fatty acids and the like on substrates, and deals more particularly with a barrier mechanism for isolating a drive chain from an active chamber in such a Langmuir trough to prevent contamination of the active chamber.
A basic procedure for the deposition of a monomolecular layer of fatty acid on a substrate was originally developed by Dr. Irving Langmuir. According to this procedure, a monomolecular layer was spread on the surface of water in a trough, and then compressed by a movable barrier supported at the height of the layer. This movement of the barrier also aligned the molecules such that a hydrophilic end of each molecule was oriented adjacent to the water surface and a hydrophobic end of each molecule was oriented above and out of the water. Then, a substrate, typically positioned in a vertical plane, was lowered into the water through the monomolecular layer and, in the process thereof, coated with the monomolecular layer. If this process was repeated, or if the substrate was subsequently raised out of the water through the monomolecular layer, another layer was deposited on the substrate over the first layer. Alternately, the substrate could initially be positioned in the water before the monomolecular layer was spread on the water's surface, and then the substrate raised out of the water to deposit a single monomolecular layer on the substrate.
The coated substrates have various applications. For example, if the substrate is a semi-conductor wafer and the molecules are cross linkable upon exposure to ultraviolet light, the monomolecular layer or layers on the wafer can be hardened by exposure to ultraviolet light and used to form masks to define an etching pattern on the wafer. In another application, the monomolecular layer or layers can be hardened and to form a dielectric of precise thickness in electronic components. In still another application, multilayer films having nonlinear optical properties can be obtained by appropriate alternation or other sequencing of films having an optically active chromophore and another film that does not. Multilayers of this type may possess second harmonic generation properties.
It was also previously known to provide a Langmuir trough divided into two active chambers by a lock, and to deposit layers of different molecules on the surface of water in each chamber. Then, the molecules on the surface of the water in each chamber were compressed, and a substrate lowered into one chamber, moved laterally beneath the water surface through the lock into the other chamber, and then raised out of this other chamber. The result was the deposition of two different or alternating layers on the substrate.
It was also previously known to divide a Langmuir trough into two active chambers by a fixed central barrier supported at the surface of the water in the chambers. A monomolecular layer of one type was deposited on the surface of the water in one chamber and a monomolecular layer of another type was deposited on the surface of the water in the other chamber, and both layers were compressed. A chain driven substrate was then circulated downwardly into one chamber through the respective monomolecular layer, arcuately passed underneath the central barrier, and finally passed upwardly through the other chamber and the other monomolecular layer to provide two alternate monomolecular layers on the substrate. However, a potential problem has developed in this technique because the chain can possibly transport molecules of one type from one chamber into the other chamber and thereby contaminate the other chamber.
Accordingly, a general object of the present invention is to provide a barrier mechanism to isolate the drive chain in the aforesaid system from one or both of the chambers to prevent molecules of one type from one chamber from being carried by the chain into the other chamber.
Another general object of the present invention is to provide a barrier mechanism to isolate a drive chain or the like from an active chamber in other types of Langmuir troughs.
Another, more specific object of the present invention is to provide a barrier mechanism of the foregoing type which does not interfere with the movement of the substrate or the associated chain. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to rope suspension system for an elevator.
2. Description Of Related Art
Elevators generally include a bed, a motor attached to the bed, a motor shaft, a traction sheave so mounted on the shaft that its plane of rotation is inclined relative to the vertical plane, and at least one diverter pulley. Generally, the suspension ropes in such suspension systems for elevators run from the elevator car to the traction sheave via a route between the traction sheave and the diverter pulley, so that the ropes after passing around the traction sheave run to the diverter pulley via a route proximal to that of the ropes extending towards the traction sheave, the counterweight being suspended on the ropes coming from the diverter pulley.
In current practice, gearless elevators operated at high speeds, such as 2.5 to 10 m/s, use traction sheaves and diverter pulleys provided with rope grooves that have a semicircular cross-section. Such practice necessitates the use of a so-called "double-wrap" suspension, hereinafter referred to as DW suspension, in order to achieve sufficient friction between the ropes and the traction sheave. In DW suspensions, each rope is passed twice around the traction sheave, so that the total angle of contact between each rope and the traction sheave is about 310.degree. to 330.degree.. In fast DW elevators, the suspension ratio is 1:2, by which is meant the rope speed equals twice the car speed. In such elevator systems the ropes going downwards from the traction sheave and diverter pulley are not attached, respectively, to the elevator car and the counterweight but rather are attached to an external fixed structure near the top of the hoistway, the elevator car and the counterweight being suspended on the ropes by pulleys. The high rope speed results in increased noise and vibration in the car. To reduce the noise level, insulation arrangements and their attendant costs are required.
There are many other disadvantages associated with DW suspensions. In 1:2 DW suspensions, the rope has to undergo as many as twelve diversions, which together with the high rope speed causes wear of the ropes and fatigue fractures in the rope wires. In addition, the traction sheave is subjected to a heavy radial load resulting from the large number of rope loops around it, which naturally imposes certain restrictions regarding the choice of a motor. An associated result is the so-called DW effect, in which in certain conditions of wear of the rope grooves, a large force acting between the traction sheave and the diverting pulley and tending to bend the shaft of the traction sheave is developed within the suspension mechanism.
There are also rope suspension systems designed for use with light-weight geared elevators. An example is Finnish patent 56813, which discloses an elevator with a suspension system using at least one diverter pulley to guide the suspension ropes in such manner that the ropes going to the traction sheave cross the ropes leaving it, the angle of contact between the ropes and the traction sheave being within the range of 210.degree. to 250.degree. and the distance between the point of crossing of the ropes and the point of their contact with the traction sheave equalling 1.9 to 0.7 times the traction sheave diameter. The traction sheave is slightly inclined to enable the ropes to run clear of each other at the crossing point. However, the angle between the ropes and the traction sheave is a disadvantage, causing a sideways pull and therefore heavy wear of the ropes.
A similar rope suspension system is proposed in British patent publication 2,148,229, according to which the rope grooves are provided with polyurethane inserts. However, that solution has the disadvantage that the polyurethane wears out quickly due to the lateral pull and the heat generated.
An object of the present invention is to achieve a rope suspension system which reduces of the above-mentioned drawbacks while still preserving substantially the same friction between the ropes and the traction sheave, providing a longer rope life. | {
"pile_set_name": "USPTO Backgrounds"
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It is well known that in the production of steel, especially strip steel, in order to improve the quality of the surface of the steel, it is subjected to treatment with a solution of hydrochloric acid. This step is called “pickling”, and the resultant liquor from this step containing ferrous chloride FeCl2 is called “waste pickle liquor” (WPL). In general, the waste pickle liquor from such a treatment comprises an aqueous solution of about 3-5% HCl and 15-20 weight percent of ferrous chloride. In rare occasions, the WPL may comprise ferrous sulfate FeSO4 in case the pickling is performed using sulfuric acid H2SO4. Ferrous sulfate may also arise as a byproduct of Ti-production.
Several methods have been proposed for economically treating the pickle liquor in order to dispose of same and/or for converting the liquor to an easily disposable and/or useful product, e.g. ferric chloride (FeCl3). For example, one process involves treating the pickle liquor with chlorine gas in order to convert the ferrous chloride to ferric chloride. However, chlorine gas Cl2(g) is not always available and requires the presence of a production unit, e.g. an electrolysis unit. If Cl2 would be supplied in liquid phase, then cost, toxicity and safety problems usually arise. Oxygen O2, hydrochloric acid HCl in liquid phase and sulfuric acid H2SO4 can be made more easily available in large quantities as they are routinely transported.
US application US 2003/211031 discloses a process for producing ferric chloride whereby pickle liquor containing ferrous chloride and fortified with sufficient HCl is converted to ferric chloride in the presence of oxygen in a tower at a temperature above 132° F. The ferric chloride solution from the tower is subjected to evaporation so as to increase the concentration of the ferric chloride. The resultant concentrate is recycled into the tower until a concentration of about 40% by weight ferric chloride is obtained. A gas phase from either or both of the tower and the evaporator is scrubbed in order to remove HCl which can be used to fortify the pickle liquor. Flow rates are 1000-1500 gallons/min.
Japanese application JP 2002-001365 discloses a simple method of recycling an etching waste liquid by defects in the conventional ejector method for recycling iron chloride from etching waste water. A ferrous chloride solution is hereby oxidized by supplying oxygen containing gas using an ejector mechanism, whereby the free hydrochloric acid concentration in the oxidation reaction liquid is maintained at 1 mass % or less, to manufacture a ferric chloride solution. The method disclosed in this application seems to work only at high temperatures and at slow reaction rate.
U.S. Pat. No. 5,489,380 discloses an apparatus and a process for the biological purification of sewage, with which sewage, containing dissolved pollutants, and air are fed together to a reactor via at least two mutually separate nozzles. To achieve a high substance exchange in the reactor, the streams of the two-substance mixture emanating from the nozzles are conducted such that they make impact with each other in the said reactor in an impact zone. The sewage is passed from the reactor into Pa settling tank, in which bio sludge settles. This document does not disclose the possibility of chlorinating or oxychlorinating ferrous iron in a solution to ferric iron. In fact, this document relates to the treatment of sewage with air or pure oxygen and not to the oxidation, chlorination or oxychlorination of ferrous iron. As U.S. Pat. No. 5,489,380 is concerned with purification of sewage, rest gasses which are formed after reacting with the sewage are not re-introduced as reagens into the reactor, but are extracted from the process.
There remains a need in the art for an improved method and system for oxidizing metal ions, in particular for oxidizing ferrous iron Fe(II) to ferric iron Fe(III), which may be operated both in continuous and in batch mode and preferably in continuous mode, with improved reaction rates, at lower temperatures than state of the art techniques and at or near atmospheric pressure, and which has better scalability properties, i.e. wherein the production rate can be increased more efficiently by scaling up the installation than in the case of scaling up prior art techniques.
The present invention thereto aims to provide a method and system with an increased oxidation rate of a metal ion such as ferrous iron to ferric iron as compared to prior art methods and systems, which furthermore comprises improved scalability and versatility in production rate and operation parameters, which is further capable of oxidizing ferrous iron at atmospheric pressure or about atmospheric pressure if desired, and in a continuous way.
An objective of the present invention is not only to provide an improved process for treating pickle liquor, but also to provide a process for the conversion of ferrous iron to ferric iron, and in particular of: ferrous chloride to ferric chloride; ferrous sulfate to ferric chloro-sulfate; and/or ferrous sulfate to ferric sulfate,irrespective of the source of the ferrous iron. Another object is to provide a system to conduct the process. | {
"pile_set_name": "USPTO Backgrounds"
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In accordance with a common construction of the prior art, a box car end 10 is provided with an offset portion 12 and a corrugated portion 14, usually of steel construction. The box car end 10 is welded to a flat metal end liner 20 leaving a space 22 between liner 20 and offset portion 12. The assembly of liner 20 and end 10 is then suspended by means of appropriate overhead crane means (not shown) and is brought above the floor portion of the box car indicated generally at 30. Already in place and comprising the lower or floor portion of the car is an end sill 32 comprising a generally horizontal portion 34 and a generally vertically extending portion 36. Welded or otherwise appropriately affixed to end sill 32 is a floor panel support member 40. Panel support member 40 comprises a lower generally vertically extending portion 42 and a generally horizontally extending portion 44 which is welded to end liner 20 at 43 and supports on its upper surface a floor panel member 48. Floor panel member 48 extends along horizontal portion 44 of floor panel support 40 but terminates at a point 50 wherein it is welded or otherwise affixed to horizontal portion 44 leaving a space or gap 52.
However, prior to welding the panel support to the end sill and the panel to the panel support, in order to obtain engagement of the end and end liner assembly with the end sill 32 it is necessary to lower the end and end liner assembly and in such a way as to have the vertical portion 36 of the end sill enter into the opening 22 defined by offset 12 and flat end liner 20. This is a difficult operation. It is often time consuming and occasionally dangerous.
In order to provide an unobstructed end area 51, countersunk fasteners, for example, huck bolts 58 are usually utilized to hold the liner and end in engagement with the vertical extension of the end sill. The countersinking of the end liner and extension 36 indicated respectively at 54 and 56 and the drilling of holes 57 in offset portion 12 is done prior to lowering the end and end liner over the end sill extension. However, it often occurs that there is misalignment between the countersunk holes 54 in the end sill as compared with holes 56 in the end liner and/or holes 57. As a result it is often necessary to recountersink in order to put the fasteners in place. This is a time consuming operation and when a whole assembly line may be held up with such operations, the expense is greatly multiplied.
In another construction shown in FIG. 3 a fastener 59 is utilized to hold the end 10 and liner 20 in engagement with the end sill 32 and vertical extension 36. The fastener is not countersunk and the head 59a extends into the car so that when the horizontal portion 44 of the floor panel support is welded to the liner 20 an inwardly inclined extension 44a is provided which provides an obstruction in the car which can damage lading and/or make it difficult to pack in the end area 51 of the car.
Another prior art construction utilizes a corrugated end liner in which mechanical fasteners are placed between or below the corrugations which hold the end sill vertical extension in engagement with the offset portion of the end. A panel support is welded to the horizontal portion of the end sill and to the lower portion of the corrugations and/or the vertical extension of the end sill. However, in this construction the end of the car is obstructed to the extent of the corrugations. Also, the corrugations may damage some ladings. Furthermore, a corrugated end is weaker than a flat steel end, particularly with regard to bending applied longitudinally to the end of the car.
Still another prior art construction is shown in FIG. 4 wherein the end 10 and the flat end liner 20 are integral throughout the lateral extent of the car. The end has no offset 12 and a weld, for example, as shown at 11 holds the members together. This construction does avoid the obstructions in the end area such as 44a in FIG. 3 and the countersunk construction in FIG. 2. However, many customers are opposed to an integral end and end sill because if the end of the car is damaged the entire car end structure must be disassembled, for example, by torch burning, resulting in considerable expense and downtime to repair the car. For this reason the integral end and end sill construction is not desired by many customers.
It therefore is an object of the present invention to provide a box car end construction which leaves the end portion of the car unobstructed.
It is another object of the present invention to avoid the step of lowering the end liner and offset of the end into alignment with a vertical extension of the end sill.
It is another object of the present invention to avoid the problem of misaligned drilled and/or countersunk holes in the end structure of the car after the vertical extension has been placed within the opening defined by the liner and offset end portion.
Another object of the present invention is to avoid an integral end and end sill construction.
Another object of the present invention is to provide a fabrication technique which is less expensive than prior techniques.
Other objects will be apparent from the drawings and the following description. | {
"pile_set_name": "USPTO Backgrounds"
} |
The increasing number of electronic devices in the vehicle has made it necessary to display a greater quantity of information therein. Modern vehicles encompass a multitude of driver assistance systems, for example, whose information must be displayed in the vehicle. Moreover, vehicles often include a navigation system. Such a navigation system may be used to display digital geographic road maps including a route and, in some instances, multifarious supplementary information. Finally, in many cases, modern vehicles encompass communication and multimedia applications, including a cell phone interface and devices for playing back music and voice. For these applications, it must also be possible to display information in the vehicle.
To be able to flexibly display the multifarious information, freely programmable displays are used, for example, which frequently assume the playback task performed by conventional mechanical instruments. German Published Patent Application No. 10 2006 032 118 describes an instrument cluster for a motor vehicle, for example, that includes a display which may be used to variably display the velocity of the motor vehicle, the speed of the motor vehicle engine, the temperature of the motor vehicle engine, the tank level and/or the time. Moreover, information from a navigation system, a phone, a music system, an infotainment system and/or an air conditioning system may be displayed.
In addition to the instrument cluster, a display device, in which further information may be displayed, is frequently configured above the center console of the vehicle. This display device is used, in particular, as a multifunctional display and for displaying a geographic map of a navigation system. Such a multifunctional display is described, for example, in German Published Patent Application No. 199 41 956.
PCT Published Patent Application No. WO 2009/024474 describes a method for displaying information where a two-dimensional object is graphically displayed on a display. The graphical object includes a display field and an operator control field. The display field is shown on one side of the two-dimensional graphical object and the operator control field on the other side thereof. In response to an input by an input device, the graphic data to be displayed on the display are modified in a manner that causes the graphical object to rotate from one side to the other in a perspective representation on the display.
Very special requirements arise in connection with the displaying of information in a vehicle. In the vehicle, the information is acquired, inter alia, by the driver. Thus, it is imperative that the information be displayed in the vehicle in a manner that does not distract the driver when he/she acquires information while driving. Therefore, the driver should be able to intuitively and quickly acquire the displayed information, so that he/she only needs to avert his/her gaze very briefly from the driving situation in order to acquire information. If the operation of the vehicle devices is supported or managed by a display, the display should be provided in a manner that only requires the driver to glance very quickly at the display in order to implement the operation.
Also, when information is displayed in mobile devices, it should be able to be acquired quickly and intuitively. It is, namely, often the case that the user of the mobile device acquires the displayed information while he/she is performing other tasks. In this context, the problem also arises that the display area of a mobile device is often relatively small, so that it is especially important that the displayed information be readily comprehensible, and that a change in the information content be easy to follow. | {
"pile_set_name": "USPTO Backgrounds"
} |
The present invention relates, in general, to a bed, and more particularly to a hospital bed or nursing bed of a type including a frame with movable components which are adjustable by at least one electric motor accommodated in a casing and actuated by a control block which includes a printed circuit board and is disposed within the casing or externally onto the casing or separately from the casing.
Hospital beds or nursing beds are known in many designs. Oftentimes, the patient is incapable to adjust the frame, for example the leg portion or the back portion so that the adjustment must be carried out by the nursing staff. Therefore, beds are increasingly in demand which are equipped with drives to adjust the movable components so that the patient is only required to operate a hand switch to initiate the adjustment whereby certain functions, in particular those provided for therapy are triggered solely by the nursing staff.
The drive or drives are designed to best suit the required operations. Typically, hospitals or nursing homes place several beds in a single room. While each bed is equipped with a reading lamp, in situations when the patient needs to get up during nighttime and thus the lighting for the room is turned off, it is normally necessary for another person that is not bed-ridden to switch on the reading lamp. In addition, other patients in the room may become annoyed when a reading lamp is turned on during nighttime for a patient to leave the bed. Still, it is necessary to illuminate the respective area around the bed to allow a patient to safely leave the bed and subsequently get back into the bed. While it is conceivable to install a night lamp underneath the bed frame securely fix it thereto, it is still necessary, regardless of its configuration, to connect the lamp to an electric wall outlet via a fixed or loose cable. The presence of such a cable is, however, annoying in particular during daily cleaning works. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention relates to writing pens having ink eradicator or correction means and more particularly to a writing pen having a reservoir containing a correction fluid and removable brush applicator.
2. Brief Description of the Prior Art
Writing pens having ink eradicators and erasing means are known in the art. The listed patents are the best prior art known to the inventor:
Weaver, U.S. Pat. No. 2,481,803 discloses an applicator for ink eradicators wherein an eradicator fluid well is mounted in a fountain pen cap having a removable cover. A tube has one end extending into the well and its other end provided with a rubber sponge. In order to eradicate ink, the cover of the cap is removed and the pen is inverted allowing the eradicator fluid to flow through the tube and moisten the sponge. The sponge is then applied to the ink to be eradicated. This device also uses gravitational force to apply the eradicator fluid.
Maxwell, U.S. Pat. No. 3,941,488 discloses a marker having an erasing unit at the opposed end. The erasing unit comprises an enclosing barrel having a porous tip applicator and an inner wick of glass wool impregnated with a chemical reagent to bleach the dye or ink.
Neidhardt, U.S. Pat. No. 3,733,139 discloses a combination pen having a ball point cartridge at one end and a felt tip cartridge at the other.
Lin, U.S. Pat. Nos. 4,156,657 and 4,227,930 disclose a reversable pen having a compartment for ink and an opposed compartment for eradicator fluid. There is no brush applicator. These patents are directed toward the chemical composition of the eradicator fluid.
Prior, U.S. Pat. No. 3,341,884 discloses a holder having a nail polish receptable and a polish remover receptacle mounted at opposed ends. The polish receptacle has a hollow brush applicator which is screwed onto the open end of the receptacle to extend inwardly and covered with a cap in a stored position. To apply polish, the brush is unscrewed, inverted, and screwed onto the receptacle to extend outwardly. Gravitational force causes polish to flow through the hollow brush. The polish receptacle may also be compressed by a small handle to pneumatically force the polish through the brush.
The prior art in general, and these patents in particular, do not disclose a writing pen with a reservoir for a white-out type of correction fluid and a brush applicator. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to a structure of an image display apparatus which forms an image with an electron-emitting device.
2. Related Background Art
In this type of image display apparatus, an electron emitted from an electron-emitting device is transmitted through an accelerating electrode which accelerates the electron, and a phosphor member made of a fluorescent material and the like is irradiated with the electron. In the phosphor member, a bright spot (light-emission spot) is generated in a region irradiated with the electron, and the image is formed by the plural bright spots (hereinafter sometimes individual phosphor member is referred to as pixel).
However, the electrons with which the phosphor member is irradiated are scattered on the phosphor member (hereinafter the electron is referred to as “scattered electron”). When the scattered electrons are incident to the adjacent pixel again, a phenomenon called halation in which the scattered electrons causes the light emission from the adjacent pixel is generated, which results in troubles such as color drift.
Therefore, recently many technologies which suppress the halation are disclosed. For example, U.S. Pat. No. 5,639,330 discloses the image display apparatus in which a thickness of the accelerating electrode is adjusted in order to suppress efficiency of re-incidence of the scattered electron to the phosphor member of not more than 30%.
However, in the image display apparatus disclosed in U.S. Pat. No. 5,639,330, the light emission caused by the electrons other than the scattered electrons is also suppressed while the light emission caused by the halation is suppressed. Namely, the light emission caused by the proper electrons emitted from the electron-emitting device is suppressed. Therefore, since the intended brightness cannot be obtained, further improvement is demanded from the viewpoints of high brightness and high contrast. | {
"pile_set_name": "USPTO Backgrounds"
} |
Photoactivation of fluorescence is a powerful technique for the study of biological molecules in living cells. In particular, this method allows the study of dynamic cellular processes by providing a means to make fiducial marks on biopolymers, monitor biomolecule diffusion, trace cell lineage, and differentiate between two or more populations of a biomolecule (e.g., newly synthesized proteins vs. older proteins, or nucleic acids). Examples of photoactivatable fluorophores include caged fluorescein and photoactivatable green fluorescent protein (PA-GFP). More recently, the use of photochromic proteins such as Kaede (Ando et al., Proc. Natl. Acad. Sci. U.S.A., 99:12651-12656 (2002)) have allowed the discrimination between two different populations of a biomolecule by a shift in the fluorescence emission wavelength after photoactivation.
Photoactivation of PA-GFP can be used to temporally mark a protein population, but it is restricted to green fluorescence. The photoconvertable proteins, Kaede and EOS, (Wiedenmann et al., Proc. Natl. Acad. Sci. U.S.A. 101:15905-15910 (2004)) shift their fluorescence from green to red upon irradiation with long-wave UV light. However, Kaede is an obligate tetramer, and EOS monomer fusion constructs do not express at physiological temperatures. Thus, these proteins can not currently be used in a general method to tag proteins of interest and mark their localization in cells. None of these fluorescent proteins efficiently emit light in the near-IR (>650 nm), where autofluorescence is lowest and light penetration through living tissue is highest. In addition, all of these proteins are relatively large in size (27 kD for the Kaede monomer) and can interfere with the proper localization and function of the protein under study.
Photoactivation of small molecule fluorophores has thus far been mostly limited to o-nitrobenzyl (oNB)-based caged derivatives of coumarin, fluorescein, Q-rhodamine, and resorufin. In these dyes, fluorescence in the caged dye is reduced by either i) alkylation of a free phenolic hydroxyl in the parent dye with an oNB derivative (e.g., present in coumarin, fluorescein and resorufin) or, ii) carbamoylation of a secondary aryl amine with an oNB derivative (e.g., in Q-rhodamine). Photocleavage of the oNB moiety restores the structure of the parent dye, resulting in a large increase in fluorescence. Many exemplary fluorophores either lack suitable free phenol or aryl amine functionality, or such modified derivatives are still fluorescent, and thus are not amenable to the chemical modifications required to render them photoactivatable using this approach. For example, longer-wavelength far-red and near-IR rhodamine and oxazine dyes that have tertiary aryl amines are not compatible with this approach.
While caged-fluorescein is the most widely-used photoactivatable fluorophore, it is highly hydrophobic, poorly soluble in water, and labeled protein tends to aggregate. Moreover, its synthesis is difficult and the fluorescein chromophore bleaches very rapidly. Photocaged coumarin is photoactivated at the same wavelength used to visualize coumarin fluorescence, which greatly limits its use. Photocaged Q-rhodamine is difficult to synthesize and uncages slowly, and caged resorufin is chemically unstable in cell extract. Furthermore, both caged fluorescein and caged Q-rhodamine have two photolabile groups each. Thus, restoration of full fluorescence is a stepwise process, as it requires the removal of both groups, and leads to a heterogeneous population of fluorescent molecules. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention relates to an improvement in the creep resistance of melt-fabricable fluoropolymers, and more particularly to an additive to the fluoropolymer that increases its creep resistance.
2. Description of Related Art
U.S. Pat. No. 4,163,742 (Mansure) discloses the blending of carbon fibers with melt-fabricable tetrafluoroethylene copolymer resin to improve resistance to creep. The copolymer resin has a melt viscosity of 104 to 107 poises at 380° C., which corresponds to a melt flow rate at 372° C. of about 0.1 to 50 g/10 min. and the fibers have an average length of at least 2 mm. The blending process involves the mixing together of the resin in particle form with the carbon fibers in a mixture of water and a water-miscible organic solvent, followed by filtering, drying to form a filter cake of the resin/fiber blend, and compression molding. Blend compositions containing up to 50 wt % carbon fiber are disclosed. U.S. Pat. No. 4,414,356 (Michel) discloses the practice of the same blending and compression molding processes, but requires the carbon fibers also having an average length of at least 2 mm to be free of surface treatment.
U.S. Pat. No. 4,422,992 (Michel) discloses that the Mansure process does not lend itself to acceptable continuous commercial production. The Michel process involves the co-feeding of (a) the melt-fabricable tetrafluoroethylene copolymer having the melt flow characteristics disclosed in Mansure and (b) continuous carbon fiber into a twin screw extruder, wherein the extruder chops the fiber into 1.5 to 3 mm lengths. Shorter fibers are disclosed to compromise the reinforcing characteristics of the fiber. The extruder melt blends the chopped fiber and the copolymer resin and extrudes the resultant blend through a 2 to 4 mm diameter die opening to avoid clogging and to align the carbon fibers in the extrusion direction within the matrix of copolymer resin to maximize the reinforcement provided by the carbon fiber. The carbon fiber content of the blend is 20-35 wt %, preferably 30-35 wt %.
U.S. Pat. No. 5,604,285 (Miyamori et al.) discloses the addition of both carbon fiber and metal powder to melt-processible fluoropolymer to obtain a reduced coefficient of friction while maintaining mechanical strength. The carbon fiber length is 80 to 3000 micrometers as determined from the disclosure of average fiber diameter of 10-30 micrometers and average aspect ratio of 8 to 300, preferably 20 to 300 micrometers. The fluoropolymer has its end groups stabilized either by reaction with ammonia to form amide end groups or by fluorination, which is known to form —CF3 end groups. Injection molding is also disclosed.
U.S. Pat. No. 5,705,120 (Ueno) discloses inadequate wettability between polytetrafluoroethylene and carbon fiber and addresses this shortcoming by using a heat-treated carbon fiber, called graphite fiber, having a length of 50 micrometers to 5 mm, and having a surface treatment characterized by either carbon/oxygen ratio or by the presence of halogen or both. The fluororesin mixtures disclosed in Ueno contain 1 to 60 wt % of the specially treated graphite fiber. Compression molding and extrusion and injection molding are disclosed as fabrication methods, noting the importance of uniform admixing of the fluororesin and fiber ingredients. Only compression molding is used in the Examples.
There is a need for melt-fabricable tetrafluoroethylene copolymers that have substantially greater creep resistance than provided by the copolymer itself and that can be made by economical manufacture. | {
"pile_set_name": "USPTO Backgrounds"
} |
Display devices comprising touch-screen functionality in particular are used in mobile communications devices, tablet PCs and navigation devices and form an interface that enables an user to perform input operations by a selective contact with the display device, wherein these input operations typically are accompanied by a user interface visualized by the display device.
Also in conventional display systems, as for example in computer displays, an implemented touch-screen function may offer appealing possibilities of interaction in order to coordinate hereby for example menu selections, cursor movements or image movements as for example the rotation of 3D objects displayed on the display system.
It is known from several patent applications of the applicant, in particular from DE 10 2009 030 495 A1 to design a display device such that besides a touch-screen function it also allows for the detection of the finger of a user before it contacts the display device. In order to also allow the detection of a position of a finger in an area in front of the display device in addition to the contact of the display also specific separate electrodes are provided in addition to the electrode system serving the contact detection which allow to detect changes of the electric properties or states in an area in front of the display device and to derive signals therefrom which allow for a relatively high resolution position detection of the finger of a user. The electrodes serving the contact detection and the electrodes for contactless position detection provided separately therefrom may be enabled consecutively by a time division multiplexer device. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention relates to household room air purifiers of the type filtering room air to remove particulates down to very small sizes with efficiencies of 95% and more. More particularly, the invention relates to room air purifiers of a convenient quarter-round shape that will fit into a corner, that mount their own fans and motors, and that put out high volumes of air, in the hundreds of cubic feet per minute.
2. Description of the Related Art
Numerous household room air purifiers are known. Some incorporate so-called HEPA filters; others rely on electrostatic principles to separate unwanted particulate from the room air or use ozone generation to give a sense of fresh air. Continuing improvement efforts in known devices and a number of newly introduced devices signal that the best room air purifier is not yet found. | {
"pile_set_name": "USPTO Backgrounds"
} |
Sputtering is a method of depositing thin metal and insulating films onto semiconductor wafers. Sputtering is a term used to describe a physical mechanism in which atoms are dislodged from the surface of a material by collision with high energy particles. It can be compared to throwing steel balls at a concrete wall. Upon impact, the ball tears away fragments of the concrete, resulting in fragments which retain the chemical and physical properties of the concrete. If the process is continued, surfaces in the vicinity of the impact are covered with a layer of concrete dust. In sputtering, the "steel balls" are ionized atoms, typically argon, and the "wall" is a plate of material to be sputtered, commonly referred to as the "target".
Sputtering takes place in an evacuated chamber. Ionized argon atoms are introduced into the chamber which contains the wafers and a target of the film material to be sputtered. In diode sputtering, the target is maintained at a negative potential relative to the positively charged argon atom. This causes the positive ion to be accelerated towards the negatively charged target. The argon atoms slam into the target, thus tearing off some of the target material. Since the chamber is maintained at a vacuum, the liberated material settles on everything in the chamber, including wafers positioned therein. Two kinds of diode sputtering methods include direct current and radio frequency sputtering. Other sputtering methods include the triode and magnetron methods. Regardless of the method, ionized atoms are caused to accelerate toward the target, thus shearing material therefrom at the atomic level and depositing very thin films on semiconductor wafers and everything else in the sputtering chamber.
One drawback of sputtering is the difficulty in achieving conformal coverage deep within high aspect ratio steps or contacts on semiconductor wafers. The problem is described with reference to FIG. 1. Such illustrates a semiconductor wafer fragment 10 comprised of a bulk substrate material 12 having a deep contact opening 14 formed therein. In sputtering, the trajectory of the atomic material sputtered from the target depends in significant part upon the incident angle of the bombarding atom. Accordingly, atoms directed towards the wafer surface come from varying angles, only a comparatively small portion of which arrive at the wafer surface in a substantially perpendicular angle. The downwardly directed arrows shown in FIG. 1 are representative of the varying angles with which the depositing atoms strike the wafer. Such provides an undesired drawback of not conformally coating deep within contacts, as the quantity of perpendicularly angled atoms is small in comparison to the other angled atoms. This results in what is commonly known as a bread-loafing, non-conformal deposit of a metal layer 16, as shown.
To overcome such drawback, a device known as a collimator is used, such as is diagrammatically represented in FIG. 2 with reference numeral 18. Collimator 18 typically comprises a disk-shaped object having a plurality of round holes or openings 20 provided therethrough. A collimator functions effectively as a filter, essentially allowing only the perpendicularly angled atoms to pass therethrough and coat wafer 12. This results in a more conformal deposition within deep contacts than is possible when a collimator is not used. Layer 17 depicts such a deposited layer.
Collimators, like everything else within a sputtering chamber, of course also get coated with the sputtering material. Such results in the effect illustrated by FIG. 3. Collimator 18 gets coated with the sputtered deposited material 16 producing balled-up gatherings 16a of material 16. This at some point effectively diminishes the diametric size of openings 20 to where the deposition rate on a wafer 12 becomes unsatisfactory. Existing techniques involving collimators require them to be removed and cleaned such that sputtering can continue in a desired manner and rate.
Unfortunately, it is a tedious and costly job of cleaning collimators. The sputtering chamber must be effectively shut down and vacuum broken such that the collimators can be removed for cleaning. Presently, the service lifetime of a collimator is typically one-third that of the typical replacement life for a target in sputter deposition methods in semiconductor wafer processing.
It would be desirable to provide methods or techniques for increasing collimator lifetime to a point where such at least equals that of the target lifetime, enabling coincident servicing of the target and collimator. | {
"pile_set_name": "USPTO Backgrounds"
} |
The present invention relates to cribs and other usable objects (e.g., child usable objects). More particularly, the present invention pertains to crib attachments and other breathable apparatus that, for example, protect infants or young children from harm, e.g., crib attachments that prevent or protect infants or young children when in a crib from getting into one or more problematic situations, e.g., getting limbs extended and caught between crib slats or chewing on crib rails, siblings poking sharp objects into the crib, etc.
For example, conventional baby cribs include side rails that are made up of top and bottom horizontal bars interconnected by a series of spaced supports (e.g., vertical slats). Frequently, babies and toddlers, while sleeping or playing in their cribs, intentionally or accidentally extend their limbs out of the crib between the slats and have difficulty drawing them back into the crib. If this occurs when the child is sleeping, the extended limbs will remain uncovered and become cold, and the child will be ultimately awakened. Many cribs also have headboards and footboards that are also made with spaced-apart supports and the baby may also extend its arms or legs out of the crib between these slats.
Although various types of apparatus have been used to prevent such problematic situations (e.g., extension of limbs outside of the crib through the spaced-apart supports), many of such apparatus exhibit their own problems. For example, as described herein, ventilation may be problematic (e.g., such as that leading up to and resulting in suffocation). For example, crib bumper pads are widely used in cribs for protecting a child from injury caused by bodily impact of the child against the sides of the crib that define the interior boundary of the crib. However, in many cases, such crib bumpers do not allow for adequate ventilation within the crib and obstruct view of the child.
Infants usually breathe through the nasal passages. However, during crying or in the event their nasal passages are blocked, infants may breathe through their oral cavities. Mechanical resistance suffocation takes places when respiration is interrupted if these passages are both blocked externally by an object. When respiration is interrupted, CO2 levels in the blood rise. The body's response to this elevation in CO2 levels is to attempt more rigorous respiration. If the agent of suffocation is not removed, the incident may be fatal after two or three minutes. Further, the accumulation of CO2 or other dangerous gases inside the crib may be a possible cause of sudden infant death syndrome (SIDS). Existing crib apparatus, such as crib bumper pads, tend to trap dangerous gases inside the crib. Further, such apparatus may block the passages of infants under certain circumstances.
Various types of other crib apparatus have been described and attempt to reduce one or more of the above problems. For example, such apparatus are described in U.S. Pat. No. 5,881,408 to Bashista et al., entitled “Mesh Crib Liner,” issued 16 Mar. 1999; and U.S. Pat. No. 6,178,573 to Wagner et al., entitled “Ventilation Upgrade Kit for a Crib Bumper and Method of Using It.” | {
"pile_set_name": "USPTO Backgrounds"
} |
The invention relates to force sensing apparatus and in particular, force sensing apparatus for monitoring the bond force in an ultrasonic welding machine.
Ultrasonic welding is commonly used for wire bonding when packaging semiconductor devices and for other bonding operations. Force sensors are used in the ultrasonic wire bonding machines to either monitor the quality of the wire bond by measuring the bond force or to generate the required bond force in response to signals from the sensor.
In some arrangements the force sensor is located in a structure which is external from and isolated from the transducer. In other designs, the force sensor is mounted on the transducer body itself.
Sensors residing on the body of the ultrasonic transducer are normally of the balanced strain gauge design. They measure the surface strains produced by bending of the transducer during bonding and thus indirectly obtain information regarding the bond force. However, as they contact the transducer body they exert a load on the transducer, which interferes with the operation of the transducer.
Force sensors located in force arms external to the bond-head are, in general, not compact.
In general, piezoelectric force sensors and electrorestrictive force sensors suffer from the problem of output voltage drift. This introduces errors in successive measurements. To overcome this problem, a number of the prior art machines (see or example, U.S. Pat. Nos. 4,903,883 and 5,607,096) use two or more sensors to mutually compensate for any drift.
However, this has the disadvantage of increasing the cost and size of the sensor arrangement and also increases the processing required for the sensor signals.
In accordance with a first aspect of the present invention, there is provided force sensing apparatus for sensing deflection of a transducer in an ultrasonic welding machine, the apparatus comprising a body member, a transducer holder adapted to hold an ultrasonic transducer, the transducer holder being fixed to the body member, and a force sensor located between adjacent surfaces of the body member and the transducer holder to sense a force applied between the surfaces.
Preferably, the force sensor senses a force applied in a direction substantially parallel to the longitudinal axis of the transducer.
Typically, the adjacent surfaces of the body member and the transducer holder are oblique to the longitudinal axis of the transducer. Preferably, the adjacent surfaces are substantially perpendicular to the longitudinal axis of the transducer.
Preferably, the force sensor comprises a piezoelectric force sensor. Alternatively, the force sensor may comprise an electrostrictive force sensor.
Preferably, the sensing apparatus comprises a biasing device located between one of the adjacent surfaces and the force sensor to provide a preload to the force sensor.
In accordance with a second aspect of the present invention, there is provided a method of compensating a force sensor for performance changes in the sensor, the method comprising:
(a) at the beginning of a first time interval taking a first reference reading from the sensor with a reference force applied to the sensor;
(b) using the first reference reading as a reference for readings from the sensor during the first time interval to obtain an indication of an unknown force applied to the sensor; and
after the end of the first time interval repeating steps (a) and (b).
An advantage of this aspect of the invention is that it permits force sensors which are prone to drift by resetting the reference level for the sensor at periodic time intervals.
Preferably, the force sensor may be a piezoelectric force sensor or a electrorestrictive force sensor.
Typically, the reference reading is a reading of the voltage output from the sensor.
Typically, steps (a) and (b) are repeated as frequently as necessary to obtain a sufficiently accurate indication of the unknown force for the application in which the force sensor is being used. The length subsequent time intervals may be the same as or different from the first time interval.
Typically, the force sensor may be a force sensor for monitoring the contact force of an ultrasonic welding transducer on a workpiece. For example, the transducer may be a wire bonding transducer and the workpiece may be a contact pad of a semiconductor die or lead frame to which a wire is to be bonded by the transducer.
Preferably, where the force sensor monitors the contact force of an ultrasonic weld transducer, the first time interval corresponds to the time interval between separate welds, or between a number of welds. | {
"pile_set_name": "USPTO Backgrounds"
} |
The invention most closely corresponds with USPTO Class 119/702 wherein Class 119 relates to animal husbandry and sub-class 702 includes exercise or amusement devices for animals.
In its simplest form, the invention comprises a novel method of utilizing a two-piece hard rubber outer casing which is laced together with an edible rawhide material. The animal chews through the rawhide lacing and is able to gain access to user inserted treats contained inside the outer casing which dissembles after the lacing is chewed. The outer casing is sturdy enough that it may be reused multiple times.
An issue with current rawhide type chew treats or toys for pets is that large portions of rawhide are not safe for animals as they pose a choking hazard. Typical rawhide chew toys are also large and do not utilize an encasement type method which provides stimulation whereby the pet must perform process to access the treat. The inventive chew toy only allows for small portions of rawhide to be consumed at any given time. Further, the reusable casing provides an economical way for users to utilize the chew toy over and over as users can insert treats and lace the outer casing up with provided supplemental rawhide lacing. | {
"pile_set_name": "USPTO Backgrounds"
} |
A removable hard disk case generally includes a hard disk, a fan, a detection circuit and a enclosure-control chip. The detection circuit is used to detect the temperature, the fan's rotation speed and the voltage. The enclosure-control chip is used to collect environmental parameters and transmit them back to a host controller. A removable hard disk case of the conventional ATA (also called IDE) interface is generally connected to the host controller via a parallel ATA (PATA) bus. Using the PATA as the transmission interface, the enclosure-control chip in the removable hard disk case can transmit environmental parameters back to the host controller. The host controller also controls the enclosure-control chip in the removable hard disk case and transmits data to the hard disk via the PATA. An LED lamp is also directly connected to the enclosure-control chip in the removable hard disk case to flash when the hard disk malfunctions or is active.
Nowadays, the ATA interface evolves from parallel bus to serial bus, wherein two pairs of 1.5 GHz cables are used to transmit data at a higher speed. However, because the speed is as high as 1.5 GHz, if other external components are connected, there will be a problem of signal attenuation. Therefore, the 1.5 GHz cable can hardly be connected externally to other enclosure-control chips, or even the 1.5 GHz cable can be connected externally to other enclosure-control chips, the cost will be high. Generally, a channel of a host is connected to the hard disk via the serial ATA (SATA). The host controller is additionally connected to the LED lamp and the enclosure-control chip. However, the corresponding relation between the channel of the host and the enclosure-control chip disappears. That is, the corresponding relation between the hard disk connected to the channel and the LED lamp disappears. This will derives the following problem. When one hard disk malfunctions, the user cannot determine the hard disk corresponding to the flashing lamp. For instance, if a host controller has four serial ATA channels and can connect four hard disks, each accompanying a enclosure-control chip. Each of the enclosure-control chips has its ID. The host controller is series connected with the four enclosure-control chips via I2C interface. When the host controller finds that the hard disk of channel 1 malfunctions, it needs to let the LED lamp corresponding to channel 1 flash to notify the user to replace the hard disk. However, because the corresponding between the channel of the host and the enclosure-control chip disappears, unless the software has the capability of detecting the corresponding between the channel of the host and the ID of the enclosure-control chip, one can only assume the external wiring is the same as in the program. For instance, the program fixes the ID of the enclosure-control chip connected with channel 1 to 1, when the system performs the setting, the user must connect the cable of channel 1 to the removable hard disk case with ID 1 manually. However, manual assignment of ID easily connects wrong enclosure-control chips, resulting in the problems of incorrect flashing light and incorrect removal of hard disk.
Accordingly, the present invention aims to propose a method for detecting channels of a host to which hard disk controllers belong so as to build the corresponding relations between the channels of the host and the hard disk controllers. | {
"pile_set_name": "USPTO Backgrounds"
} |
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